Invarium, Inc.

Cadence Design Systems, Inc.

Ram S Ramanujam

Franz X Zach

Chi-Song Horng

Roy Varada Prasad

Abdurrahman Sezginer

Shigeru Suzuki

Gokhan Percin

Gökhan Perçin

Gökhan Percin

A test mask with both verification structures and calibration structures is provided to enable the formation of an image of at least one verification structure and at least one calibration structure at a plurality of different test site locations under different dose and defocus conditions to allow the calibration structures to be measured and to obtain at least one computational model for optical proximity correction purposes.

Method for verifying and choosing lithography model

A method for generating an OPC model is provided which takes into consideration across-wafer variations which occur during the process of manufacturing semiconductor chips. More particularly, a method for generating an OPC model is provided which takes into consideration across-wafer variations which occur during the process of manufacturing semiconductor chips based on the parameters of test patterns measured at the 'wafer sweet spots' so as to arrive at an accurate model.

Calibration on wafer sweet spots

This invention relates to a method for real time monitoring and verifying optical proximity correction (OPC) models and methods in production. Prior to OPC is performed on the integrated circuit layout, a model describing the optical, physical and chemical processes involving lithography should be obtained accurately and precisely. In general, the model is calibrated using the measurements obtained by running wafers through the same lithography, patterning, and etch processes. In this invention, a novel real time method for verifying and monitoring the calibrated model on a production or monitor wafer is presented: optical proximity corrected (OPC-ed) test and verification structures are placed on scribe lines or cut lines of the production or monitor wafer, and with pre-determined schedule, the critical dimensions and images of these test and verification structures are monitored across wafer and across exposure field.

Method for real time monitoring and verifying optical proximity correction model and method

The present invention provides a system and method of modifying the mask layout shapes of an integrated circuit layout design to compensate for reticle field location-specific systematic CD variations resulting from mask writing process variations, lens imperfections in lithographic patterning, and photoresist process variations. Called PLC (Process-optimized Layout Compensation), each set of compensation rules according to the present invention is specifically tailored for a particular mask-writer-patterning-tools-and-resist-process combination, and are performed on a reticle-wide basis. Furthermore, for each geometric shape in the mask layout, the amount of modification is determined based on a categorization of the type of the shape, the specific location in the reticle field the particular shape falls in, its context (i.e., surrounding patterns, orientation, etc.), as well as certain photoresist parameters to be used in the patterning process.

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San Jose, CA, United States of America

Ram S Ramanujam