Patent US527049A successfully refreshed from Google Patents.
Patent US5103182A successfully refreshed from Google Patents.
US5103182A
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US
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Electromagnetic wave measurement of conductive layers of a semiconductor wafer during processing in a fabrication chamber
Assignee: Texas Instruments Inc
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Filing: 1990-04-02
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Granted: 1992-04-07
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Expires: 2010-04-02
Abstract
Abstract A non-invasive sensor system (50) for real-time in situ measurements of sheet resistance and thickness of conductive layers of a semiconductor wafer. The sensor (50) includes a microwave source (78) for generating a plurality of microwave signals. An emitter waveguide (52) receives the plurality of microwave signals from the microwave source (78) and emits the microwave signals in the direction of the semiconductor wafer (20) in fabrication chamber (18). The collector waveguide (84) detects the reflected microwave signals from the semiconductor wafer (20). A dual directional coupler (64) communicates with emitter waveguide (52) to direct the microwave signals to and from the emitter waveguide (52) and to generate a plurality of electrical signals that relate to semiconductor wafer (20), conductive layer (108), and deposition vapor physical characteristics. These physical characteristics include conductive layer thickness, resistivity, and substrate temperature. An alternative embodiment provides measurements of plasma vapor density and other interferometric parameters.
Inventors
- 👤 Mehrdad M. Moslehi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:02
CPC Classifications
H; H10; H10P; H10P74/00; H10P74/20; H10P74/203; G; G01; G01D; G01D5/00; G01D5/48; G01B; G01B15/00; G01B15/02; G01K; G01K11/00; H10P74/207; H10P74/27
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
185 words
An apparatus for non-invasive, real-time, in situ measurement of conductive layers of a semiconductor wafer during processing in a fabrication chamber, comprising: an electromagnetic signal source for generating electromagnetic waves; an emitter waveguide in communication with said electromagnetic wave source and fabrication chamber for emitting said electromagnetic waves through the chamber and toward the semiconductor wafer, said emitter waveguide spaced from said conductive layer such that said emitter waveguide is not invasive to said process, and also for detecting a portion of electromagnetic waves reflected from the semiconductor wafer; at least one coupler in communication with said emitter waveguide for generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to the power of said emitter electromagnetic waves and a reflected set of electrical signals proportional to the power of said portion of said electromagnetic waves that the semiconductor wafer reflects, said plurality of electrical signals from said at least one coupler being directly related to measurements of the semiconductor wafer conductive layer; and circuitry for converting said plurality of electrical signals into conductive layer measurements.
Claim 2
Independent Claim
185 words
An apparatus for non-invasive, real-time, in situ measurement of conductive layers of a semiconductor wafer during processing in a fabrication chamber, comprising: an electromagnetic signal source for generating electromagnetic waves; an emitter waveguide in communication with said electromagnetic wave source and fabrication chamber for emitting said electromagnetic waves through the chamber and toward the semiconductor wafer, said emitter waveguide spaced from said conductive layer such that said emitter waveguide is not invasive to said process, and also for detecting a portion of electromagnetic waves reflected from the semiconductor wafer; at least one coupler in communication with said emitter waveguide for generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to the power of said emitter electromagnetic waves and a reflected set of electrical signals proportional to the power of said portion of said electromagnetic waves that the semiconductor wafer reflects, said plurality of electrical signals from said at least one coupler being directly related to measurements of the semiconductor wafer conductive layer; and circuitry for converting said plurality of electrical signals into conductive layer measurements.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 wherein the fabrication chamber for said non-invasive, real-time, in situ measurement of conductive layers of a semiconductor wafer comprises a vapor deposition chamber.
Claim 4
Dependent Claim
29 words
The apparatus of claim 1 wherein the fabrication chamber for said non-invasive, real-time, in situ measurement of conductive layers of a semiconductor wafer comprises a conductive layer etch chamber.
Claim 5
Dependent Claim
30 words
The apparatus of claim 1 wherein said at least one coupler comprises a dual directional coupler for communicating among said electromagnetic wave source, said emitter waveguide, and said converting circuitry.
Claim 6
Dependent Claim
59 words
The apparatus of claim 1 wherein said electromagnetic waves have a frequency range bounded by a lower frequency and an upper frequency, said lower frequency producing a signal wavelength that is small relative to the dimensions of the semiconductor wafer and said upper frequency providing for optimal measurement sensitivity to electromagnetic wave interaction to be with the conductive layer.
Claim 7
Dependent Claim
28 words
The apparatus of claim 1 wherein said emitter waveguide further comprises a microwave transmitter for transmitting said electromagnetic waves and a microwave detector for detecting said electromagnetic waves.
Claim 8
Dependent Claim
18 words
The apparatus of claim 1, further comprising, a collector waveguide for collecting a portion of said electromagnetic waves.
Claim 9
Dependent Claim
22 words
The apparatus of claim 1, wherein said electromagnetic wave source comprises a low frequency solid state frequency source capable of frequency scanning.
Claim 10
Dependent Claim
26 words
The apparatus of claim 8, further comprising a microwave signal chopper within said electromagnetic wave source for electronically chopping said electromagnetic waves to improve signal-to-noise ratios.
Claim 11
Dependent Claim
22 words
The apparatus of claim 1, further comprising a plurality of detectors for measuring a predetermined aspect of said portion of electromagnetic waves.
Claim 12
Dependent Claim
29 words
The apparatus of claim 10, further comprising a process control computer for calculating conductive layer electromagnetic wave reflectance measurements as a function of said emitted and reflected electromagnetic waves.
Claim 13
Dependent Claim
32 words
The apparatus of claim 11, further comprising a plurality of electronically recorded look-up tables within said computer for automatically converting semiconductor wafer electromagnetic wave reflectance measurements into conductive film physical property measurements.
Claim 14
Dependent Claim
35 words
The apparatus of claim 11, further comprising a plurality of look-up tables that relate to conductive layer etchings for converting said electromagnetic wave reflectance measurements into conductive layer thickness and sheet measurements during etch processes.
Claim 15
Dependent Claim
30 words
The apparatus of claim 11, further comprising a plurality of look-up tables that relate to silicon dopant levels for converting said electromagnetic wave reflectance measurements into silicon substrate dopant levels.
Claim 16
Dependent Claim
30 words
The apparatus of claim 11, further comprising a plurality of look-up tables that relate to semiconductor wafer temperatures for converting said electromagnetic wave reflectance measurements into semiconductor wafer temperature measurements.
Claim 17
Dependent Claim
39 words
The apparatus of claim 11, wherein the deposition chamber contains plasma vapors and further comprising a plurality of look-up tables that relate to plasma density for converting said electromagnetic wave reflectance measurements into plasma vapor electromagnetic wave interaction measurements.
Claim 18
Dependent Claim
23 words
The apparatus of claim 1 wherein said emitter waveguide is spaced from said conductive layer between about 1.18 inches and about 3.4 inches.
Claim 19
Independent Claim
305 words
An apparatus for non-invasive, real-time in situ measurements of conductive layers of a semiconductor wafer during processing in a fabrication chamber, comprising: an electromagnetic wave source for generating electromagnetic waves and comprising a low-power solid state microwave signal source capable of frequency scanning and a microwave signal chopper for electronically chopping said electromagnetic waves; an emitter waveguide in communication with said electromagnetic wave source and within the fabrication chamber, said emitter waveguide comprising a microwave transmitter spaced from said conductive layer such that said emitter waveguide is not invasive to said process and for transmitting said electromagnetic waves through the chamber and toward the semiconductor wafer and a plurality of microwave detectors for detecting a predetermined aspect of said electromagnetic waves reflected from the semiconductor wafer, said electromagnetic waves having a frequency range bounded by a lower frequency and an upper frequency, said lower frequency producing a signal wavelength that is small relative to the dimensions of the semiconductor wafer and said upper frequency providing for optimal measurement sensitivity to electromagnetic wave interaction with the conductive layer on a semiconductor substrate; a dual directional coupler for communicating among said electromagnetic wave source and said emitter waveguide, said dual directional coupler comprising measuring circuitry for generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to the power of said electromagnetic waves and a reflected set of electrical signals proportional to the power of said portion of said reflected electromagnetic waves, said plurality of electrical signals from said at least one coupler being directly related to measurements of the semiconductor wafer conductive layer; a process control computer for calculating conductive layer electromagnetic wave reflectance measurements as a function of said emitted and reflected electromagnetic waves; and a plurality of electronically recorded look-up tables sets within said calculator.
Claim 20
Independent Claim
305 words
An apparatus for non-invasive, real-time in situ measurements of conductive layers of a semiconductor wafer during processing in a fabrication chamber, comprising: an electromagnetic wave source for generating electromagnetic waves and comprising a low-power solid state microwave signal source capable of frequency scanning and a microwave signal chopper for electronically chopping said electromagnetic waves; an emitter waveguide in communication with said electromagnetic wave source and within the fabrication chamber, said emitter waveguide comprising a microwave transmitter spaced from said conductive layer such that said emitter waveguide is not invasive to said process and for transmitting said electromagnetic waves through the chamber and toward the semiconductor wafer and a plurality of microwave detectors for detecting a predetermined aspect of said electromagnetic waves reflected from the semiconductor wafer, said electromagnetic waves having a frequency range bounded by a lower frequency and an upper frequency, said lower frequency producing a signal wavelength that is small relative to the dimensions of the semiconductor wafer and said upper frequency providing for optimal measurement sensitivity to electromagnetic wave interaction with the conductive layer on a semiconductor substrate; a dual directional coupler for communicating among said electromagnetic wave source and said emitter waveguide, said dual directional coupler comprising measuring circuitry for generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to the power of said electromagnetic waves and a reflected set of electrical signals proportional to the power of said portion of said reflected electromagnetic waves, said plurality of electrical signals from said at least one coupler being directly related to measurements of the semiconductor wafer conductive layer; a process control computer for calculating conductive layer electromagnetic wave reflectance measurements as a function of said emitted and reflected electromagnetic waves; and a plurality of electronically recorded look-up tables sets within said calculator.
Claim 21
Dependent Claim
33 words
The apparatus of claim 18, wherein said plurality of electronically recorded look-up tables comprises a set of look-up tables for converting semiconductor wafer electromagnetic wave reflectance measurements into conductive film physical property measurements.
Claim 22
Dependent Claim
29 words
The apparatus of claim 18, wherein said plurality of electronically recorded look-up tables comprises a set of look-up tables for converting said reflectance measurements into conductive layer etching measurements.
Claim 23
Dependent Claim
30 words
The apparatus of claim 18, wherein said plurality of electronically recorded look-up tables comprises a set of look-up tables for converting said reflectance measurements into silicon substrate dopant level measurements.
Claim 24
Dependent Claim
29 words
The apparatus of claim 18, wherein said plurality of electronically recorded look-up tables comprises a set of look-up tables for converting said reflectance measurements into semiconductor wafer temperature measurements.
Claim 25
Dependent Claim
31 words
The apparatus of claim 18, wherein said plurality of electronically recorded look-up tables comprises a set of look-up tables for converting said reflectance measurements into plasma vapor electromagnetic wave interaction measurements.
Claim 26
Dependent Claim
23 words
The apparatus of claim 18 wherein said emitter waveguide is spaced from said conductive layer between about 1.18 inches and about 3.4 inches.
Claim 27
Independent Claim
149 words
A method for performing non-invasive real-time in situ semiconductor wafer conductive layer measurements during processing in a fabrication chamber, comprising the steps of: spacing an emitter waveguide within said fabrication chamber and from said conductive layer such that said emitter waveguide is not invasive to said process; generating electromagnetic waves; emitting said electromagnetic waves from said emitter waveguide toward the semiconductor wafer; detecting a portion of said electromagnetic waves that the semiconductor wafer reflects within the fabrication chamber; generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to said electromagnetic waves and a reflected set of electrical signals proportional to said portion of said electromagnetic waves that the semiconductor wafer reflects, said plurality of electrical signals being directly related to the semiconductor wafer conductive layer measurements; and converting said plurality of electrical signals into semiconductor wafer conductive layer measurements.
Claim 28
Independent Claim
149 words
A method for performing non-invasive real-time in situ semiconductor wafer conductive layer measurements during processing in a fabrication chamber, comprising the steps of: spacing an emitter waveguide within said fabrication chamber and from said conductive layer such that said emitter waveguide is not invasive to said process; generating electromagnetic waves; emitting said electromagnetic waves from said emitter waveguide toward the semiconductor wafer; detecting a portion of said electromagnetic waves that the semiconductor wafer reflects within the fabrication chamber; generating a plurality of electrical signals, said plurality of electrical signals comprising an emitted set of electrical signals proportional to said electromagnetic waves and a reflected set of electrical signals proportional to said portion of said electromagnetic waves that the semiconductor wafer reflects, said plurality of electrical signals being directly related to the semiconductor wafer conductive layer measurements; and converting said plurality of electrical signals into semiconductor wafer conductive layer measurements.
Claim 29
Dependent Claim
15 words
The method of claim 25, further comprising the step of electronically chopping said electromagnetic waves.
Claim 30
Dependent Claim
36 words
The method of claim 25 wherein said step of generating a plurality of electrical signals further comprises the step of producing DC voltages proportional to said emitted set of signals and said reflected set of signals.
Claim 31
Dependent Claim
41 words
The method of claim 25, wherein the semiconductor wafer contains a patterned conductive layer formed by etching from said conductive layer and said converting step further comprises the step of converting said plurality of electrical signals into etching end-point detection measurements.
Claim 32
Dependent Claim
26 words
The method of claim 25, wherein said detecting step further comprises the step of detecting said portion of reflected electromagnetic waves at different deposition process temperatures.
Claim 33
Dependent Claim
20 words
The method of claim 25, further comprising the step of converting said plurality of signals to semiconductor substrate dopant levels.
Claim 34
Dependent Claim
24 words
The method of claim 25, wherein said converting step further comprises the step of converting said plurality of signals into semiconductor wafer temperature measurements.
Claim 35
Dependent Claim
22 words
The method of claim 25 wherein said spacing step said emitter waveguide is spaced between about 1.18 inches and about 3.4 inches.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1995-04-07 | 1995-10-07 | 1996-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-07 | 1999-10-07 | 2000-04-07 | $3760.00 | Window Closed / Lapsed |
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