Patent US4999014A successfully refreshed from Google Patents.
US4999014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring thickness of thin films
Assignee: Therma Wave Inc
•
Filing: 1989-05-04
•
Granted: 1991-03-12
•
Expires: 2009-05-04
Abstract
Abstract An apparatus (20) for measuring the thickness of a thin film layer (32) on substrate (28) includes a probe beam of radiation (24) focused substantially normal to the surface of the sample using a high numerical aperture lens (30). The high numerical aperture lens (30) provides a large spread of angles of incidence of the rays within the incident focused beam. A detector (50) measures the intensity across the reflected probe beam as a function of the angle of incidence with respect to the surface of the substrate (28) of various rays within the focused incident probe beam. A processor (52) functions to derive the thickness of the thin film layer based on these angular dependent intensity measurements. This result is achieved by using the angular dependent intensity measurements to solve the layer thickness using variations of the Fresnel equations. The invention is particularly suitable for measuring thin films, such as oxide layers, on silicon semiconductor samples.
Inventors
- 👤 Nathan Gold
- 👤 David L. Willenborg
- 👤 Jon Opsal
- 👤 Allan Rosencwaig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:48
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/21; G01N21/211
Claims Analysis
Total Claims: 67
Claim 1
Independent Claim
145 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam substantially normal onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position with the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 2
Independent Claim
145 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam substantially normal onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position with the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 3
Independent Claim
163 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein said focused incident probe beam includes at least one ray substantially normal to the surface of the substrate; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 4
Independent Claim
163 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein said focused incident probe beam includes at least one ray substantially normal to the surface of the substrate; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 5
Dependent Claim
35 words
An apparatus as recited in claim 1 or 2 wherein said focused incident probe beam includes at least one ray inclined near Brewster's angle with respect to either the thin film layer or the substrate.
Claim 6
Independent Claim
161 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface, wherein said focusing means is defined by a lens having a numerical aperture of at least 0.5; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and a processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 7
Independent Claim
161 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface, wherein said focusing means is defined by a lens having a numerical aperture of at least 0.5; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and a processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 8
Independent Claim
172 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface, wherein the variation in the angle of incidence of the rays of the focused incident probe beam, from the center to the outer edge, is at least 30 degrees; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 9
Independent Claim
172 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface, wherein the variation in the angle of incidence of the rays of the focused incident probe beam, from the center to the outer edge, is at least 30 degrees; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 10
Independent Claim
152 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam to a diameter of about one micron or less onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 11
Independent Claim
152 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam to a diameter of about one micron or less onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 12
Independent Claim
206 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein the light in said probe beam is linearly polarized prior to being focused by said focusing means and wherein said probe beam is focused substantially normal to the surface of the substrate such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 13
Independent Claim
206 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein the light in said probe beam is linearly polarized prior to being focused by said focusing means and wherein said probe beam is focused substantially normal to the surface of the substrate such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means.
Claim 14
Dependent Claim
57 words
An apparatus as recited in claim 7 wherein said detector means isolates and measures the angular dependent intensity of the S and P polarized components of said focused incident probe beam and said processor means utilizes the angular dependent intensity measurement of the S and P polarized light to determine the thickness of the thin film layer.
Claim 15
Dependent Claim
49 words
An apparatus as recited in claim 8 wherein said detector means includes means for measuring the intensity of the reflected probe beam along two orthogonal axes oriented in a manner to isolate the angular dependent intensity of the S and P polarized components of said focused incident probe beam.
Claim 16
Independent Claim
188 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means and wherein said processor means determines the thickness of the thin film layer using a mathematical model which relates the angular dependent intensity measurements made by the detector means, angle of incidence, polarization of the rays of the focused incident probe beam and layer thickness.
Claim 17
Independent Claim
188 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means and wherein said processor means determines the thickness of the thin film layer using a mathematical model which relates the angular dependent intensity measurements made by the detector means, angle of incidence, polarization of the rays of the focused incident probe beam and layer thickness.
Claim 18
Independent Claim
192 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means and wherein said detector means further functions to measure the total power of the reflected probe beam and wherein said processor means determines the thickness of the thin film layer based upon both the angular dependent intensity measurements and the total reflected power measurements made by the detector means.
Claim 19
Independent Claim
192 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements made by the detector means and wherein said detector means further functions to measure the total power of the reflected probe beam and wherein said processor means determines the thickness of the thin film layer based upon both the angular dependent intensity measurements and the total reflected power measurements made by the detector means.
Claim 20
Dependent Claim
39 words
An apparatus as recited in claim 11 wherein said processor utilizes the angular dependent intensity measurements to approximate the thickness of the thin film layer and utilizes the total reflected power measurement to reduce the uncertainty of the result.
Claim 21
Independent Claim
196 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of linearly polarized radiation; lens means for focusing said probe beam substantially normal to the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam in a manner to isolate the S and P polarization components, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements of the S and P polarized light made by the detector means.
Claim 22
Independent Claim
196 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of linearly polarized radiation; lens means for focusing said probe beam substantially normal to the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam in a manner to isolate the S and P polarization components, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent intensity measurements of the S and P polarized light made by the detector means.
Claim 23
Dependent Claim
49 words
An apparatus as recited in claim 13 wherein said detector means includes means for measuring the intensity of the reflected probe beam along two orthogonal axes oriented in a manner to isolate the angular dependent intensity of the S and P polarized components of said focused incident probe beam.
Claim 24
Dependent Claim
77 words
An apparatus as recited in claim 13 wherein said focused incident probe beam has at least one ray having a substantial component of P polarized light inclined near Brewster's angle with respect to the thin film layer and wherein said processor means further functions to determine information as to the index of refraction of said thin film layer based on the measurement of the intensity of reflected P polarized light incident on the sample near Brewster's angle.
Claim 25
Dependent Claim
29 words
An apparatus as recited in claim 13 wherein said incident probe beam is focused to a diameter of about one micron or less on the surface of the substrate.
Claim 26
Independent Claim
164 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate, such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer using a mathematical model which relates the angular dependent intensity measurements made by the detector means, angle of incidence, polarization of the rays of the focused incident probe beam and layer thickness.
Claim 27
Independent Claim
164 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate, such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer using a mathematical model which relates the angular dependent intensity measurements made by the detector means, angle of incidence, polarization of the rays of the focused incident probe beam and layer thickness.
Claim 28
Dependent Claim
33 words
An apparatus as recited in claim 17 wherein said lens means has a numerical aperture of at least 0.5 and said probe beam is focused substantially normal to the surface of the substrate.
Claim 29
Dependent Claim
29 words
An apparatus as recited in claim 17 wherein said incident probe beam is focused to a diameter of about one micron or less on the surface of the substrate.
Claim 30
Independent Claim
192 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; first detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said first detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; second detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said second detector means for measuring the total power of the reflected probe beam; and processor means for determining the thickness of the thin film layer based upon both the angular dependent intensity measurements made by the first detector means and the total reflected power measured by the second detector means.
Claim 31
Independent Claim
192 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; first detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said first detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; second detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said second detector means for measuring the total power of the reflected probe beam; and processor means for determining the thickness of the thin film layer based upon both the angular dependent intensity measurements made by the first detector means and the total reflected power measured by the second detector means.
Claim 32
Dependent Claim
38 words
An apparatus as recited in claim 20 wherein said processor utilizes the angular dependent intensity measurements to approximate the thickness of the thin film layer and utilizes the total reflected power to reduce the uncertainty of the result.
Claim 33
Dependent Claim
33 words
An apparatus as recited in claim 20 wherein said lens means has a numerical aperture of at least 0.5 and said probe beam is focused substantially normal to the surface of the substrate.
Claim 34
Dependent Claim
29 words
An apparatus as recited in claim 20 wherein said incident probe beam is focused to a diameter of about one micron or less on the surface of the substrate.
Claim 35
Independent Claim
228 words
An apparatus for evaluating parameters of a sample which includes a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the sample such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining parameters of the sample including the thickness of the thin film layer and the index of refraction of the thin film layer or the substrate based upon the angular dependent intensity measurements made by the detector means and wherein the light in said probe beam is linearly polarized prior to being focused by said lens means and wherein sad probe beam is focused substantially normal to the surface of the substrate such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface.
Claim 36
Independent Claim
228 words
An apparatus for evaluating parameters of a sample which includes a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the sample such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining parameters of the sample including the thickness of the thin film layer and the index of refraction of the thin film layer or the substrate based upon the angular dependent intensity measurements made by the detector means and wherein the light in said probe beam is linearly polarized prior to being focused by said lens means and wherein sad probe beam is focused substantially normal to the surface of the substrate such that light rays incident on the sample surface have substantial components of S and P polarized light with respect to the plane of incidence at the sample surface.
Claim 37
Dependent Claim
56 words
An apparatus as recited in claim 24 wherein said detector means isolates and measures the angular dependent intensity of the reflected S and P polarized components of said focused incident probe beam and said processor means utilizes the angular dependent intensity measurement of the S and P polarized light to determine the parameters of the sample.
Claim 38
Dependent Claim
49 words
An apparatus as recited in claim 25 wherein said detector means includes means for measuring the intensity of the reflected probe beam along two orthogonal axes oriented in a manner to isolate the angular dependent intensity of the S and P polarized components of said focused incident probe beam.
Claim 39
Dependent Claim
77 words
An apparatus as recited in claim 25 wherein said focused incident probe beam has at least one ray having a substantial component of P polarized light inclined near Brewster's angle with respect to the thin film layer and wherein said processor means further functions to determine information as to the index of refraction of said thin film layer based on the measurement of the intensity of reflected P polarized light incident on the sample near Brewster's angle.
Claim 40
Independent Claim
174 words
An apparatus for evaluating parameters of a sample which includes a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam to a diameter of about one micron or less onto the surface of the sample such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining parameters of the sample including the thickness of the thin film layer and the index of refraction of the thin film layer or the substrate based upon the angular dependent intensity measurements made by the detector means.
Claim 41
Independent Claim
174 words
An apparatus for evaluating parameters of a sample which includes a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam to a diameter of about one micron or less onto the surface of the sample such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the probe beam after it has been reflected from the surface of the substrate, said detector means for measuring the intensity of various rays as a function of position within the reflected probe beam, with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining parameters of the sample including the thickness of the thin film layer and the index of refraction of the thin film layer or the substrate based upon the angular dependent intensity measurements made by the detector means.
Claim 42
Independent Claim
186 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein said lens means has a numerical aperture of at least 0.5 and said probe beam is focused substantially normal to the surface of the substrate; detector means for receiving the reflected probe beam, said detector means for measuring the interference effected created by the interaction between the rays of the probe beam reflecting off the thin film layer and the upper surface of the underlying substrate as a function of position within the reflected probe beam, with the position of the interference effects within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent interference effects measured made by the detector means.
Claim 43
Independent Claim
186 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising: means for generating a probe beam of radiation; lens means for focusing said probe beam onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein said lens means has a numerical aperture of at least 0.5 and said probe beam is focused substantially normal to the surface of the substrate; detector means for receiving the reflected probe beam, said detector means for measuring the interference effected created by the interaction between the rays of the probe beam reflecting off the thin film layer and the upper surface of the underlying substrate as a function of position within the reflected probe beam, with the position of the interference effects within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent interference effects measured made by the detector means.
Claim 44
Independent Claim
168 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising; means for generating a probe beam of radiation; lens means for focusing said probe beam to a diameter of about one micron or less onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the reflected probe beam, said detector means for measuring the interference effects created by the interaction between the rays of the probe beam reflecting off the thin film layer and the upper surface of the underlying substrate as a function of position within the reflected probe beam, with the position of the interference effects within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent interference effects measured made by the detector means.
Claim 45
Independent Claim
168 words
An apparatus for measuring the thickness of a thin film layer on the surface of a substrate comprising; means for generating a probe beam of radiation; lens means for focusing said probe beam to a diameter of about one micron or less onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; detector means for receiving the reflected probe beam, said detector means for measuring the interference effects created by the interaction between the rays of the probe beam reflecting off the thin film layer and the upper surface of the underlying substrate as a function of position within the reflected probe beam, with the position of the interference effects within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and processor means for determining the thickness of the thin film layer based upon the angular dependent interference effects measured made by the detector means.
Claim 46
Independent Claim
25 words
An apparatus as recited in claims 29 or 30 wherein said interference effects in said reflected probe beam are in the form of intensity variations.
Claim 47
Independent Claim
51 words
An apparatus as recited in claims 1, 2, 4, 5, 6, 7, 10, 11, 17, 24, 28, 29 or 30 wherein said detector means measures the intensity across the reflected probe beam at a plurality of discrete points, from the center of the reflected probe beam to the outer edge thereof.
Claim 48
Independent Claim
113 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam substantially normal onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 49
Independent Claim
113 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam substantially normal onto the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 50
Independent Claim
139 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface wherein said incident probe beam is focused in a manner such that it includes at least one ray that is substantially normal to the surface of the substrate; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 51
Independent Claim
139 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface wherein said incident probe beam is focused in a manner such that it includes at least one ray that is substantially normal to the surface of the substrate; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 52
Independent Claim
144 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface wherein said incident probe beam is focused in a manner to include at least one ray that is inclined near Brewster's angle with respect to either the thin film layer or the substrate; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 53
Independent Claim
144 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface wherein said incident probe beam is focused in a manner to include at least one ray that is inclined near Brewster's angle with respect to either the thin film layer or the substrate; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 54
Independent Claim
143 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incident with respect to said surface wherein the incident probe beam is focused in a manner such that the variation in the angle of incidence of the rays with respect to the substrate is at least 30 degrees; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 55
Independent Claim
143 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incident with respect to said surface wherein the incident probe beam is focused in a manner such that the variation in the angle of incidence of the rays with respect to the substrate is at least 30 degrees; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 56
Independent Claim
120 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam to a diameter of about one micron or less on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 57
Independent Claim
120 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam to a diameter of about one micron or less on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 58
Independent Claim
169 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein the light in said probe beam is linearly polarized prior to being focused and wherein said probe beam is directed substantially normal to the surface of the substrate such that the light incident on said substrate includes substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 59
Independent Claim
169 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface and wherein the light in said probe beam is linearly polarized prior to being focused and wherein said probe beam is directed substantially normal to the surface of the substrate such that the light incident on said substrate includes substantial components of S and P polarized light with respect to the plane of incidence at the sample surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements.
Claim 60
Dependent Claim
53 words
A method as recited in claim 38 further including the steps of: isolating the angular dependent intensity variations of the S and P polarized components of said focused incident probe beam; and determining the thickness of the thin film layer utilizing the angular dependent intensity measurement of the S and P polarized light.
Claim 61
Dependent Claim
50 words
A method as recited in claim 39 wherein said isolation step is performed by measuring the intensity of the reflected probe beam along two orthogonal axes oriented in a manner to isolate the angular dependent intensity variations of the S and P polarized components of said focused incident probe beam.
Claim 62
Dependent Claim
71 words
A method as recited in claim 39 wherein said incident probe beam has at least one ray having a substantial component of P polarized light inclined near Brewster's angle with respect to the thin film layer and further including the step of determining the index of refraction of said thin film layer based on the measurement of the intensity of reflected P polarized light incident on the sample near Brewster's angle.
Claim 63
Independent Claim
149 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements and wherein the thickness of the thin film is calculated using a mathematical model which relates the angular dependent intensity measurements, angle of incidence and polarization of the rays of the focused incident probe beam with layer thickness.
Claim 64
Independent Claim
149 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; and determining the thickness of the thin film layer based upon the angularly dependent intensity measurements and wherein the thickness of the thin film is calculated using a mathematical model which relates the angular dependent intensity measurements, angle of incidence and polarization of the rays of the focused incident probe beam with layer thickness.
Claim 65
Independent Claim
126 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; measuring the total power of the reflected probe beam; and determining the thickness of the thin film layer based upon both the angular dependent intensity measurements and the total reflected power.
Claim 66
Independent Claim
126 words
A method of measuring the thickness of a thin film layer on the surface of a substrate comprising the steps of: generating a probe beam of radiation; focusing the probe beam on the surface of the substrate such that various rays within the focused probe beam create a spread of angles of incidence with respect to said surface; measuring the intensity of various rays as a function of position within the reflected beam with the position of the rays within said reflected probe beam corresponding to specific angles of incidence with respect to said surface; measuring the total power of the reflected probe beam; and determining the thickness of the thin film layer based upon both the angular dependent intensity measurements and the total reflected power.
Claim 67
Dependent Claim
39 words
A method as recited in claim 43 wherein the angular dependent intensity measurements are utilized to approximate the thickness of the thin film layer and the total reflected power measurement is utilized to reduce the uncertainty of the result.
References Cited (Backward Citations)
US2587282A
Cited
US2897371A
Cited
US2973686A
Cited
US3017512A
Cited
US3601492A
Cited
US3708229A
Cited
US3737237A
Cited
US3824017A
Cited
JPS533363A
Cited
US4293224A
Cited
US4358201A
Cited
US4355903A
Cited
US4308586A
Cited
US4367044A
Cited
US4453828A
Cited
US4555767A
Cited
US4582431A
Cited
US4660980A
Cited
US4672196A
Cited
US4611919A
Cited
US4618262A
Cited
US4660979A
Cited
US4645349A
Cited
US4744660A
Cited
US4815856A
Cited
US4873430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-11 | 1994-09-10 | 1995-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-11 | 1998-09-10 | 1999-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-11 | 2002-09-10 | 2003-03-12 | $7700.00 | Window Closed / Lapsed |