Yunqiang Zhang from 183 Midwick Dr, Milpitas, CA 95035

Generalization Of The Photo Process Window And Its Application To Opc Test Pattern Design
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US Patent:

7568180, Jul 28, 2009
Filed:

Feb 22, 2005
Appl. No.:

10/595703
Inventors:

Hans Eisenmann - Tutzing, DE
Kai Peter - Friedberg, DE
Dennis Ciplickas - San Jose CA, US
Jonathan O. Burrows - San Jose CA, US
Yunqiang Zhang Zhang - Sunnyvale CA, US
Assignee:

PDF Solutions - San Jose CA
International Classification:

G06F 17/50
US Classification:

716 21, 716 5, 716 19
Abstract:

A method comprises the steps of: (a) simulating on a processor a fabrication of a plurality of layout patterns by a lithographic process; (b) determining sensitivities of the layout patterns to a plurality of parameters based on the simulation; (c) using the sensitivities to calculate deviations of the patterns across a range of each respective one of the parameters; and (d) selecting ones of the patterns having maximum or near-maximum deviations to be used as test patterns.

Method And Apparatus For Determining The Effect Of Process Variations
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US Patent:

7966583, Jun 21, 2011
Filed:

Jul 8, 2008
Appl. No.:

12/169278
Inventors:

Paulus J. M. Van Adrichem - Wijchen, NL
Yunqiang Zhang - Sunnyvale CA, US
Assignee:

Synopsys, Inc. - Mountain View CA
International Classification:

G06F 17/50
G06F 19/00
G06K 9/00
US Classification:

716 53, 716 51, 716 55, 382149, 700121
Abstract:

Embodiments of the present invention provide systems and techniques for determining the effect of process variations. During operation, the system can receive a layout which includes multiple instances of a pattern. Next, the system can correct the pattern instances using different photolithography process models which model the photolithography process at different exposure and focus conditions. Next, the corrected layout can be printed on a wafer. The system can then perform electrical tests on the wafer, or it can measure the critical dimensions of the features on the wafer. The yield loss or the exposure-focus matrix can then be generated by using the test data or the measurement data.

Stochastic Optical Proximity Corrections
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US Patent:

20210263407, Aug 26, 2021
Filed:

Feb 24, 2021
Appl. No.:

17/184460
Inventors:

- Mountain View CA, US
Yunqiang Zhang - Mountain View CA, US
International Classification:

G03F 1/72
G03F 1/84
Abstract:

A method of improving mask data used in fabrication of a semiconductor device includes, in part, setting a threshold value associated with a defect based on stochastic failure rate of the defect, performing a first optimal proximity correction (OPC) of the mask data using nominal values of mask pattern contours, identifying locations within the first OPC mask data where stochastically determined mask pattern contours may lead to the defect, placing check figures on the identified locations to enable measurement of distances between the stochastically determined mask pattern contours, and performing a second OPC of the first OPC mask data so as to cause the measured distances to be greater than the threshold value.

Yunqiang Zhang