US5654903A
Expired / Lapsed
US
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Method and apparatus for real time monitoring of wafer attributes in a plasma etch process
Assignee: Nokia of America Corp
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Filing: 1995-11-07
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Granted: 1997-08-05
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Expires: 2015-11-07
Abstract
Abstract The present invention provides a method and apparatus for monitoring the state of an attribute of a product during the manufacturing process. The invention employs an intelligent system trained in the relationship between the signatures of the manufacturing process and the product attribute as a function of time. In one embodiment the intelligent system comprises two intelligent systems: the first, trained in the relationship between the signatures of the manufacturing process and one or more signatures of the state of the attribute as a function of time; and the second, trained in the relationship between the product-state signatures as a function of time and the product attribute as a function of time. The disclosed apparatus can be an integral part of the manufacturing machinery allowing the process to continue until the exact moment when the desired state is achieved.
Inventors
- 👤 Edward A. Reitman
- 👤 Dale E. Ibbotson
- 👤 Tseng-Chung Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:20
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32917; H01J37/32935; G; G05; G05B; G05B13/00; G05B13/02; G05B13/0265; G05B13/027
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
144 words
A method of monitoring in real time, the state of an attribute of a product during the manufacturing process of said product, comprising the steps of: selecting one or more process signatures which characterize said manufacturing process and which have an indirect relationship to the state of said attribute; selecting one or more product-state signatures which characterize said attribute; collecting said process signatures in situ, over a period of time; inputting said previously collected process signatures to an intelligent system which has been trained in the relationship between said process signatures over a period of time and said product attribute as a function of time, said intelligent system having an output representing said attribute as a function of time; and using said output of said intelligent system to determine when a desired state of said attribute is found and to alter said manufacturing process.
Claim 2
Independent Claim
144 words
A method of monitoring in real time, the state of an attribute of a product during the manufacturing process of said product, comprising the steps of: selecting one or more process signatures which characterize said manufacturing process and which have an indirect relationship to the state of said attribute; selecting one or more product-state signatures which characterize said attribute; collecting said process signatures in situ, over a period of time; inputting said previously collected process signatures to an intelligent system which has been trained in the relationship between said process signatures over a period of time and said product attribute as a function of time, said intelligent system having an output representing said attribute as a function of time; and using said output of said intelligent system to determine when a desired state of said attribute is found and to alter said manufacturing process.
Claim 3
Dependent Claim
136 words
A method in accordance with claim 1 wherein said intelligent system comprises two intelligent systems and wherein said inputting step further comprises the steps of: inputting said previously collected process signatures to a first intelligent system which has been trained in the relationship between said process signatures over a period of time and one or more of said product state signatures as a function of time, said first intelligent system having an output representing one or more of said product state signature; and inputting said output of said first intelligent system into a second intelligent system which has been trained in the relationship between said product state signatures as a function of time and said attribute as a function of time, said second intelligent system having an output representing said attribute as a function of time.
Claim 4
Dependent Claim
30 words
A method in accordance with claim 1 wherein said selecting one or more process signatures step includes choosing one or more metrics representative of the material structures of the product.
Claim 5
Dependent Claim
17 words
A method in accordance with claim 1 wherein said intelligent system comprises one or more neural networks.
Claim 6
Dependent Claim
17 words
A method in accordance with claim 1 wherein said intelligent system comprises one or more recurrent networks.
Claim 7
Dependent Claim
18 words
A method in accordance with claim 1 wherein said intelligent system comprises one or more time delay networks.
Claim 8
Dependent Claim
14 words
A method in accordance with claim 1 wherein said product is a semiconductor wafer.
Claim 9
Dependent Claim
24 words
A method in accordance with claim 7 wherein said semiconductor wafer attribute is the post processing thickness of a film on said semiconductor wafer.
Claim 10
Independent Claim
138 words
A method of monitoring in real time, the state of an attribute of a semiconductor wafer during plasma etch processing, comprising the steps of: selecting one or more process signatures which characterize said plasma etch process and which have a cause and effect relationship to the state of said attribute; selecting one or more wafer-state signatures which characterize said attribute; collecting said process signatures in situ, over a period of time; inputting said process signatures to an intelligent system which has been trained in the relationship between said process signatures and said attribute as a function of time, said intelligent system having an output representing said attribute as a function of time; and using the output of said intelligent system to determine when a desired state of said attribute is found and to alter said plasma etch process.
Claim 11
Independent Claim
138 words
A method of monitoring in real time, the state of an attribute of a semiconductor wafer during plasma etch processing, comprising the steps of: selecting one or more process signatures which characterize said plasma etch process and which have a cause and effect relationship to the state of said attribute; selecting one or more wafer-state signatures which characterize said attribute; collecting said process signatures in situ, over a period of time; inputting said process signatures to an intelligent system which has been trained in the relationship between said process signatures and said attribute as a function of time, said intelligent system having an output representing said attribute as a function of time; and using the output of said intelligent system to determine when a desired state of said attribute is found and to alter said plasma etch process.
Claim 12
Dependent Claim
136 words
A method in accordance with claim 9 wherein said intelligent system comprises two intelligent systems and wherein said inputting step further comprises the steps of: inputting said previously collected process signatures to a first intelligent system which has been trained in the relationship between said process signatures over a period of time and one or more of said product state signatures as a function of time, said first intelligent system having an output representing one or more of said product state signature; and inputting said output of said first intelligent system into a second intelligent system which has been trained in the relationship between said product state signatures as a function of time and said attribute as a function of time, said second intelligent system having an output representing said attribute as a function of time.
Claim 13
Dependent Claim
19 words
A method in accordance with claim 9 wherein said wafer-state signature includes the ellipsometric trace of the semiconductor wafer.
Claim 14
Dependent Claim
19 words
A method in accordance with claim 9 wherein said wafer-state signature includes the interferometric trace of the semiconductor wafer.
Claim 15
Dependent Claim
26 words
A method in accordance with claim 9 wherein said selecting step includes choosing one or more metrics representative of the material structures of the semiconductor wafer.
Claim 16
Dependent Claim
26 words
A method in accordance with claim 9 wherein said selecting step includes choosing one or more metrics representative of the pattern density of the semiconductor wafer.
Claim 17
Dependent Claim
20 words
A method in accordance with claim 9 wherein said first and second intelligent system comprises one or more neural networks.
Claim 18
Dependent Claim
17 words
A method in accordance with claim 9 wherein said intelligent system comprises one or more recurrent networks.
Claim 19
Dependent Claim
18 words
A method in accordance with claim 9 wherein said intelligent system comprises one or more time delay networks.
Claim 20
Dependent Claim
19 words
A method in accordance with claim 9 wherein said attribute is the post etch thickness of the semiconductor wafer.
Claim 21
Dependent Claim
115 words
Apparatus for monitoring in real time, the state of an attribute of a product during the manufacturing process, comprising: means for collecting one or more process signatures which characterize said manufacturing process and which have an indirect relationship to the state of said attribute; an intelligent system which has been trained in the relationship between said process signatures and said attribute as a function of time; input means for inputting said process signatures to said intelligent system over a period of time; and means for creating an output signal from said intelligent system, said output signal containing information for determining when a desired state of the attribute is obtained and to stop said manufacturing process.
Claim 22
Dependent Claim
115 words
Apparatus for monitoring in real time, the state of an attribute of a product during the manufacturing process, comprising: means for collecting one or more process signatures which characterize said manufacturing process and which have an indirect relationship to the state of said attribute; an intelligent system which has been trained in the relationship between said process signatures and said attribute as a function of time; input means for inputting said process signatures to said intelligent system over a period of time; and means for creating an output signal from said intelligent system, said output signal containing information for determining when a desired state of the attribute is obtained and to stop said manufacturing process.
Claim 23
Dependent Claim
160 words
An apparatus in accordance with claim 19 wherein said intelligence system comprises two intelligent systems and further comprising: a first intelligent system which has been trained in the relationship between said process signatures and one or more product state signatures which characterize said attribute and whose output represents said one or more product state signatures of said attribute; input means for inputting said process signatures to said intelligent first system over a period of time; a second intelligent system which has been trained in the relationship between said product state signatures as a function of time and said attribute as a function of time; input means for inputting said output of said first intelligent system into said second intelligent system over a period of time; and means for creating an output signal from said second intelligent system, said output signal containing information for determining one of a desired state of the attribute is obtained and to stop said manufacturing process.
Claim 24
Dependent Claim
17 words
An apparatus in accordance with claim 19 wherein said intelligent system comprises one or more neural networks.
Claim 25
Dependent Claim
17 words
An apparatus in accordance with claim 19 wherein said intelligent system comprises one or more recurrent networks.
Claim 26
Dependent Claim
18 words
An apparatus in accordance with claim 19 wherein said intelligent system comprises one or more time delay networks.
Claim 27
Dependent Claim
14 words
An apparatus in accordance with claim 19 wherein said product is a semiconductor wafer.
Claim 28
Dependent Claim
15 words
An apparatus in accordance with claim 24 wherein said manufacturing process is plasma etch processing.
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