US6556947B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical measurements of patterned structures
Assignee: Nova Ltd
•
Filing: 2000-10-26
•
Granted: 2003-04-29
•
Expires: 2020-10-26
Abstract
Abstract A method for measuring at least one desired characteristic of a patterned article is presented. The article is of a kind containing a plurality of different pattern elements located at different sites, each including a stack of layers. An optical model is provided, which is based on a set of parameters corresponding to predetermined characteristics of the article, and is capable of generating theoretical data indicative of spectral response of the article. The set of parameters includes parameters corresponding to geometrical characteristics of the pattern elements. Reference data is prepared containing a plurality of sets of parameters for at least some of the different pattern elements. A spectral measurement of light response is carried out at a selected site of the patterned article and measured data is generated. By varying said parameters' sets, the optical model is optimized, and then the theoretical spectral responses obtained through the optimized optical model and from the measured data is analyzed to determine therefrom the at least one desired characteristic.
Inventors
- 👤 David Scheiner
- 👤 Avi Ravid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:01
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/02; G01B11/06; G01B11/0616; H; H10; H10P; H10P74/00; H10P74/20; H10P74/203
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
159 words
A method for measuring at least one desired characteristic of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of: providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking a spectral measurement of light response at a selected site of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimized optical model and from the measured data, in order to determine therefrom said at least one desired characteristic.
Claim 2
Independent Claim
159 words
A method for measuring at least one desired characteristic of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of: providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking a spectral measurement of light response at a selected site of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimized optical model and from the measured data, in order to determine therefrom said at least one desired characteristic.
Claim 3
Dependent Claim
24 words
The method according to claim 1 , wherein said analyzing includes adjusting at least one parameter corresponding to said at least one desired characteristic.
Claim 4
Dependent Claim
33 words
The method according to claim 2 , wherein said reference data is prepared by applying spectral measurements to a test article including substantially all of said pattern elements contained in the patterned article.
Claim 5
Dependent Claim
24 words
The method according to claim 2 , wherein said reference data is prepared by applying information of feature design rules and obtaining parameter sets.
Claim 6
Dependent Claim
23 words
The method according to claim 2 , wherein said reference data is prepared by applying information of layer stack and obtaining parameter sets.
Claim 7
Dependent Claim
27 words
The method according to claim 2 , wherein said reference data is prepared by applying information of feature design rules and layer stack and obtaining parameter sets.
Claim 8
Dependent Claim
26 words
The method according to claim 2 , wherein said reference data includes information on indices of refraction, n, and extinction coefficient, k, of the stack layers.
Claim 9
Dependent Claim
29 words
The method according to claim 7 , wherein the step of optimizing the optical model includes adjusting parameters corresponding to the index of refraction, n, and/or extinction coefficient, k.
Claim 10
Dependent Claim
32 words
The method according to claim 8 , wherein said parameters corresponding to the indices of refraction, n, and extinction coefficients, k, of the stack layers are included within said sets of parameters.
Claim 11
Dependent Claim
30 words
The method according to claim 7 , wherein said reference data further comprises a plurality of algorithms for performing the optimization of said optical model and determining the desired characteristic.
Claim 12
Dependent Claim
37 words
The method according to claim 10 , wherein the reference data preparation comprises selecting the algorithm suitable for performing the optimization of said optical model and determining the desired characteristic as related to the corresponding parameters' set.
Claim 13
Dependent Claim
28 words
The method according to claim 1 , wherein said desired characteristic is determined using parameters' set that provides the theoretical spectral responses most closely fitting the measured data.
Claim 14
Dependent Claim
21 words
The method according to claim 1 , wherein the desired characteristic is thickness of at least one layer of the stack.
Claim 15
Dependent Claim
23 words
The method according to claim 1 , wherein the desired characteristic is an index of refraction, n, of at least one stack layer.
Claim 16
Dependent Claim
22 words
The method according to claim 1 , wherein the desired characteristic is an extinction coefficient, k, of at least one stack layer.
Claim 17
Dependent Claim
28 words
The method according to claim 1 , wherein the desired characteristics are an index of refraction, n, and an extinction coefficient, k, of at least one stack layer.
Claim 18
Independent Claim
158 words
A method for thickness mapping of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of: providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking spectral measurements of light response at selected sites of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimized optical model and from the measured data, in order to determine therefrom the thicknesses at the selected sites, and generating the thickness map.
Claim 19
Independent Claim
158 words
A method for thickness mapping of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of: providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking spectral measurements of light response at selected sites of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimized optical model and from the measured data, in order to determine therefrom the thicknesses at the selected sites, and generating the thickness map.
Claim 20
Dependent Claim
30 words
The method according to claim 17 , wherein the thickness of the article is determined using parameters' set that provides the theoretical spectral responses most closely fitting the measured data.
Claim 21
Dependent Claim
20 words
The method according to claim 17 , wherein said thickness is that of at least one layer of the stack.
Claim 22
Independent Claim
161 words
A method for determining a surface profile of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of; providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking spectral measurements of light response at selected sites of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimization and the measured data, in order to determine therefrom the desired characteristics at the selected sites, and calculating the surface profile from said characteristics.
Claim 23
Independent Claim
161 words
A method for determining a surface profile of a patterned article containing a plurality of different pattern elements located at different sites, each including a stack of layers, the method comprising the steps of; providing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, said optical model being capable of generating theoretical data indicative of spectral response of the article; preparing reference data containing a plurality of sets of parameters for at least some of said different pattern elements; taking spectral measurements of light response at selected sites of said patterned article and generating measured data; optimizing the optical model by varying said parameters' sets; and analyzing the theoretical spectral responses obtained through the optimization and the measured data, in order to determine therefrom the desired characteristics at the selected sites, and calculating the surface profile from said characteristics.
Claim 24
Dependent Claim
21 words
The method according to claim 20 , wherein said desired characteristics are thicknesses of at least one layer of the stack.
Claim 25
Dependent Claim
26 words
The method according to claim 20 , wherein the desired characteristics are determined using parameters' set providing theoretical spectral responses most closely fitting the measured data.
Claim 26
Dependent Claim
23 words
The method according to claim 20 , wherein said optimizing of the optical model includes the step of varying predetermined sets of parameters.
Claim 27
Dependent Claim
46 words
The method according to claim 23 , wherein at least two of the variable predetermined sets of parameters correspond to characteristics of the selected sites of at least two types. 25 .The method according to claim 20 , wherein said patterned article is a semiconductor wafer.
Claim 28
Dependent Claim
35 words
The method according to claim 25 , further comprising the step of defining a location of the selected measuring site, and applying further measurements in a similar site located in at least one different die.
Claim 29
Independent Claim
28 words
The method according to claims 20 , wherein said patterned article is a semiconductor wafer and the selected sites are located within the same die of the wafer.
Claim 30
Dependent Claim
26 words
The method according to claim 20 , wherein said further measurements use the set of parameters providing theoretical spectral responses most closely fitting the measured data.
Claim 31
Independent Claim
180 words
A system for optical measuring at least one desired characteristic of a patterned article containing a plurality of pattern elements located at different sites, each including a stack of layers, the system comprising: a measuring unit including a spectrophotometer that determines spectral response of a measurement site on the article and generates spectral measured data; a memory for storing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements and said optical model is capable of generating theoretical data indicative of spectral response of the article, said memory storing a reference data containing a plurality of sets of parameters for at least some of said different pattern element; a processing unit coupled to the measuring unit for receiving the spectral measured data, optimizing the optical model by various parameters' sets contained in the reference data, analyzing the theoretical spectral responses obtained through the optimization and the measured data in order to determine therefrom said at least one desired characteristic.
Claim 32
Independent Claim
180 words
A system for optical measuring at least one desired characteristic of a patterned article containing a plurality of pattern elements located at different sites, each including a stack of layers, the system comprising: a measuring unit including a spectrophotometer that determines spectral response of a measurement site on the article and generates spectral measured data; a memory for storing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements and said optical model is capable of generating theoretical data indicative of spectral response of the article, said memory storing a reference data containing a plurality of sets of parameters for at least some of said different pattern element; a processing unit coupled to the measuring unit for receiving the spectral measured data, optimizing the optical model by various parameters' sets contained in the reference data, analyzing the theoretical spectral responses obtained through the optimization and the measured data in order to determine therefrom said at least one desired characteristic.
Claim 33
Dependent Claim
13 words
The system according to claim 29 , wherein said desired characteristic is thickness.
Claim 34
Dependent Claim
17 words
The system according to claim 29 , wherein said desired characteristic is an index of refraction, n.
Claim 35
Dependent Claim
16 words
The system according to claim 29 , wherein said desired characteristic is an extinction coefficient, k.
Claim 36
Dependent Claim
26 words
The system according to claim 29 , wherein the processing unit operates to adjust at least one parameter corresponding to said at least one desired characteristic.
Claim 37
Dependent Claim
34 words
The system according to claim 29 , wherein said reference data is prepared by applying spectral measurements to a test article including substantially all of the different pattern elements contained in the patterned article.
Claim 38
Dependent Claim
25 words
The system according to claim 29 , wherein said reference data is prepared by applying information of the feature design rules and obtaining parameter sets.
Claim 39
Dependent Claim
23 words
The system according to claim 29 , wherein said reference data is prepared by applying information of layer stack and obtaining parameter sets.
Claim 40
Dependent Claim
26 words
The system according to claim 29 , wherein said reference data includes information on indices of refraction, n, and extinction coefficient, k, of the stack layers.
Claim 41
Dependent Claim
31 words
The system according to claim 29 , wherein said reference data further comprises a plurality of algorithms suitable for performing the optimization of said optical model and determining the desired characteristic.
Claim 42
Dependent Claim
32 words
The system according to claim 29 , wherein said parameters corresponding to the indices of refraction, n, and extinction coefficients, k, of the stack layers are included within said sets of parameters.
Claim 43
Dependent Claim
14 words
The system according to claim 29 , and further comprising a pattern recognition utility.
Claim 44
Dependent Claim
13 words
The system according to claim 29 , and further comprising an auto-focusing assembly.
Claim 45
Dependent Claim
183 words
An optical profilometer for determining a surface profile of a patterned article containing a plurality of pattern elements located at different sites, each including a stack of layers, the optical profilometer comprising: a measuring unit including a spectrophotometer that determines spectral response of a measurement site on the article and generates spectral measured data; a memory for storing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, and said optical model is capable of generating theoretical data indicative of spectral response of the article, said memory storing a reference data containing a plurality of sets of parameters for at least some of said different pattern element; and a processing unit coupled to the measuring unit for receiving the spectral measured data, optimizing the optical model by various parameters' sets, analyzing the theoretical spectral responses obtained through the optimization and the measured data, in order to determine therefrom the desired characteristic at selected sites, and calculating the surface profile from said characteristic.
Claim 46
Dependent Claim
183 words
An optical profilometer for determining a surface profile of a patterned article containing a plurality of pattern elements located at different sites, each including a stack of layers, the optical profilometer comprising: a measuring unit including a spectrophotometer that determines spectral response of a measurement site on the article and generates spectral measured data; a memory for storing an optical model based on a set of parameters corresponding to predetermined characteristics of the article, wherein said set includes inter alia parameters corresponding to geometrical characteristics of the pattern elements, and said optical model is capable of generating theoretical data indicative of spectral response of the article, said memory storing a reference data containing a plurality of sets of parameters for at least some of said different pattern element; and a processing unit coupled to the measuring unit for receiving the spectral measured data, optimizing the optical model by various parameters' sets, analyzing the theoretical spectral responses obtained through the optimization and the measured data, in order to determine therefrom the desired characteristic at selected sites, and calculating the surface profile from said characteristic.
References Cited (Backward Citations)
EP0718595A2
Cited
US5963329A
Cited
US5900633A
Cited
US5889592A
Cited
US6100985A
Cited
WO1999054679A1
Cited
US6242739B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-04-28 | 2006-10-28 | 2007-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-04-28 | 2010-10-28 | 2011-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-04-28 | 2014-10-28 | 2015-04-29 | $7700.00 | Window Closed / Lapsed |