US5661669A
Expired / Lapsed
US
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Method for controlling semiconductor wafer processing
Assignee: Texas Instruments Inc
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Filing: 1995-06-07
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Granted: 1997-08-26
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Expires: 2015-06-07
Abstract
Abstract A system (10) for run-to-run control of semiconductor wafer processing is provided. An input/output device (12) receives a desired quality characteristic for a particular semiconductor fabrication process. A generating circuit (22) uses a model to generate appropriate process parameters for a processing unit (20) and an expected quality characteristic. An adjusting circuit (16) functions to adjust process parameter inputs of the processing unit (20). In-situ sensor (18) functions to measure a quality characteristic of the process in the processing unit (20) on a real-time basis. A comparing circuit (24) functions to compare the measured quality characteristic with the expected quality characteristic. A model adjusting circuit (26) may adjust the model of the generating circuit (22) if the measured quality characteristic varies from the expected quality characteristic by more than a predetermined statistical amount.
Inventors
- 👤 Purnendu Kanti Mozumder
- 👤 Gabe G. Barna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:12
CPC Classifications
G; G05; G05B; G05B17/00; G05B17/02; G05B13/00; G05B13/02; G05B13/04; G05B13/042
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
127 words
A method for run-to-run control of a processing unit, comprising: generating process parameters using a model which provides a transfer function from said process parameters to an expected quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process in real-time during said process using an in-situ sensor comprising an optical device operable on a single wavelength to generate a signal proportional to the concentration of a predetermined chemical species present during processing of the device; comparing said measured quality characteristic with said quality characteristic; and adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistic amount.
Claim 2
Independent Claim
127 words
A method for run-to-run control of a processing unit, comprising: generating process parameters using a model which provides a transfer function from said process parameters to an expected quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process in real-time during said process using an in-situ sensor comprising an optical device operable on a single wavelength to generate a signal proportional to the concentration of a predetermined chemical species present during processing of the device; comparing said measured quality characteristic with said quality characteristic; and adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistic amount.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said processing unit is a semiconductor processing unit and said device under manufacture is a semiconductor wafer.
Claim 4
Dependent Claim
27 words
The system of claim 2, wherein said adjusting step comprises operating a plurality of actuating devices operable to adjust selected process parameter inputs of the processing unit.
Claim 5
Dependent Claim
39 words
The system of claim 2, wherein said comparing step subtracts said expected quality characteristic from said measured quality characteristic to generate a difference value and averages said difference value with between two to eight difference values from previous devices.
Claim 6
Dependent Claim
61 words
The system of claim 2, wherein said sensor comprises a monochromator and further comprising the steps of: storing a value of said signal generated by said monochromator at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process.
Claim 7
Dependent Claim
35 words
The system of claim 2, wherein said adjusting step comprises adjusting a constant term of said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 8
Dependent Claim
43 words
The system of claim 2, wherein said adjusting step weights a difference between said measured quality characteristic and said expected quality characteristic for the current device with said difference for up to twenty-five previous devices to adjust a constant term of said model.
Claim 9
Independent Claim
117 words
A method for run-to-run control of a processing unit, comprising: generating process parameters using a plurality of models each of which provides a transfer function from said process parameters to at least one of a plurality of quality characteristics at least one of said characteristics being unmeasurable after said process is complete; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process in real-time during said process with an in-situ sensor; comparing the measured quality characteristics with expected quality characteristics; and adjusting the model if the measured quality characteristics vary from the expected quality characteristics by more than a predetermined statistical amount.
Claim 10
Independent Claim
117 words
A method for run-to-run control of a processing unit, comprising: generating process parameters using a plurality of models each of which provides a transfer function from said process parameters to at least one of a plurality of quality characteristics at least one of said characteristics being unmeasurable after said process is complete; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process in real-time during said process with an in-situ sensor; comparing the measured quality characteristics with expected quality characteristics; and adjusting the model if the measured quality characteristics vary from the expected quality characteristics by more than a predetermined statistical amount.
Claim 11
Dependent Claim
23 words
The method of claim 8 wherein said processing unit is a semiconductor processing unit and said device under manufacture is a semiconductor wafer.
Claim 12
Dependent Claim
27 words
The system of claim 9, wherein said adjusting step comprises operating a plurality of actuating devices operable to adjust selected process parameter inputs of the processing unit.
Claim 13
Dependent Claim
39 words
The system of claim 9, wherein said comparing step subtracts said expected quality characteristic from said measured quality characteristic to generate a difference value and averages said difference value with between two to eight difference values from previous devices.
Claim 14
Dependent Claim
61 words
The system of claim 9, wherein said sensor comprises a monochromator and further comprising the steps of: storing a value of said signal generated by said monochromator at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process.
Claim 15
Dependent Claim
35 words
The system of claim 9, wherein said adjusting step comprises adjusting a constant term of said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 16
Dependent Claim
43 words
The system of claim 9, wherein said adjusting step weights a difference between said measured quality characteristic and said expected quality characteristic for the current device with said difference for up to twenty-five previous devices to adjust a constant term of said model.
Claim 17
Independent Claim
157 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and a plurality of expected quality characteristics using a plurality of models and desired quality characteristics; adjusting selected inputs of the processing unit to process the device under manufacture using said generated process parameters; measuring a quality characteristic of said process utilizing a real-time, in-situ sensor comprising a monochromator operable to generate a signal proportional to the concentration of a predetermined chemical species present during processing of the device; storing a value of a signal generated by said monochromator at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process; comparing the measured quality characteristics with the expected quality characteristics; adjusting the model if the measured quality characteristics varies from the expected quality characteristics by more than a predetermined statistical amount.
Claim 18
Independent Claim
157 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and a plurality of expected quality characteristics using a plurality of models and desired quality characteristics; adjusting selected inputs of the processing unit to process the device under manufacture using said generated process parameters; measuring a quality characteristic of said process utilizing a real-time, in-situ sensor comprising a monochromator operable to generate a signal proportional to the concentration of a predetermined chemical species present during processing of the device; storing a value of a signal generated by said monochromator at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process; comparing the measured quality characteristics with the expected quality characteristics; adjusting the model if the measured quality characteristics varies from the expected quality characteristics by more than a predetermined statistical amount.
Claim 19
Dependent Claim
23 words
The method of claim 15 wherein said processing unit is a semiconductor processing unit and said device under manufacture is a semiconductor wafer.
Claim 20
Dependent Claim
27 words
The system of claim 16, wherein said adjusting step comprises operating a plurality of actuating devices operable to adjust selected process parameter inputs of the processing unit.
Claim 21
Dependent Claim
39 words
The system of claim 16, wherein said comparing step subtracts an expected quality characteristic from said measured quality characteristic to generate a difference value and averages said difference value with between two to eight difference value from previous devices.
Claim 22
Dependent Claim
35 words
The system of claim 16, wherein said adjusting step comprises adjusting a constant term of said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 23
Dependent Claim
43 words
The system of claim 16, wherein said adjusting step weights a difference between said measured quality characteristic and said expected quality characteristic for the current device with said difference for up to twenty-five previous devices to adjust a constant term of said model.
Claim 24
Independent Claim
104 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and an expected quality characteristic using a model and a desired quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a signal correlated to a quality characteristic of said process which is not measurable after the process is complete utilizing a real-time, in-situ sensor; comparing said measured quality characteristic with said expected quality characteristic; adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 25
Independent Claim
104 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and an expected quality characteristic using a model and a desired quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a signal correlated to a quality characteristic of said process which is not measurable after the process is complete utilizing a real-time, in-situ sensor; comparing said measured quality characteristic with said expected quality characteristic; adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 26
Dependent Claim
23 words
The method of claim 21 wherein said processing unit is a semiconductor processing unit and said device under manufacture is a semiconductor wafer.
Claim 27
Dependent Claim
27 words
The system of claim 22, wherein said adjusting step comprises operating a plurality of actuating devices operable to adjust selected process parameter inputs of the processing unit.
Claim 28
Dependent Claim
39 words
The system of claim 22, wherein said comparing step subtracts said expected quality characteristic from said measured quality characteristic to generate a difference value and averages said difference value with between two to eight difference values from previous devices.
Claim 29
Dependent Claim
61 words
The system of claim 22, wherein said sensor comprises a monochromator and further comprising the steps of: storing a value of said signal generated by said monochromator at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process.
Claim 30
Dependent Claim
35 words
The system of claim 22, wherein said adjusting step comprises adjusting a constant term of said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 31
Dependent Claim
43 words
The system of claim 22, wherein said adjusting step weights a difference between said measured quality characteristic and said expected quality characteristic for the current device with said difference for up to twenty-five previous devices to adjust a constant term of said model.
Claim 32
Independent Claim
163 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and an expected quality characteristic using a model and a desired quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process utilizing a real-time, in-situ monochromator for measuring a signal correlated to a non-directly observable quality characteristic of said process and generating a signal proportional to the concentration of a predetermined chemical species present during processing of the device; storing a value of signal at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process; comparing said measured quality characteristic with said expected quality characteristic; adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 33
Independent Claim
163 words
A method for run-to-run control of a processing unit, comprising: generating process parameters and an expected quality characteristic using a model and a desired quality characteristic provided by a user; adjusting selected inputs of the processing unit to process a device under manufacture using said generated process parameters; measuring a quality characteristic of said process utilizing a real-time, in-situ monochromator for measuring a signal correlated to a non-directly observable quality characteristic of said process and generating a signal proportional to the concentration of a predetermined chemical species present during processing of the device; storing a value of signal at predetermined intervals during the processing to generate data representative of an optical emission trace; and converting a slope at an end-point of said optical emission trace to a quality characteristic for the process; comparing said measured quality characteristic with said expected quality characteristic; adjusting said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 34
Dependent Claim
23 words
The method of claim 28 wherein said processing unit is a semiconductor processing unit and said device under manufacture is a semiconductor wafer.
Claim 35
Dependent Claim
27 words
The system of claim 29, wherein said adjusting step comprises operating a plurality of actuating devices operable to adjust selected process parameter inputs of the processing unit.
Claim 36
Dependent Claim
39 words
The system of claim 29, wherein said comparing step subtracts said expected quality characteristic from said measured quality characteristic to generate a difference value and averages said difference value with between two to eight difference values from previous devices.
Claim 37
Dependent Claim
35 words
The system of claim 29 wherein said adjusting step comprises adjusting a constant term of said model if said measured quality characteristic varies from said expected quality characteristic by more than a predetermined statistical amount.
Claim 38
Dependent Claim
43 words
The system of claim 29, wherein said adjusting step weights a difference between said measured quality characteristic and said expected quality characteristic for the current device with said difference for up to twenty-five previous devices to adjust a constant term of said model.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 7.5 Years (Year 8) | 2004-08-25 | 2005-02-24 | 2005-08-26 | $3760.00 | Window Closed / Lapsed |
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