Proteus, Progen, Prospector Full-Chip Optical Proximity Correction

Overview
Proteus Progen, and Prospector form a comprehensive and powerful environment for performing full-chip proximity correction, building models for correction, and analyzing proximity effects on corrected and uncorrected IC layout patterns. The high level of programmability and flexibility built into these tools ensures an optimal match to your processing objectives and constraints.

Proteus, the core correction processing engine, combines an efficient hierarchy manager with proprietary, high-speed simulation algorithms. Proteus is typically parallelized across clusters of computers resulting in reliable, accurate full-chip corrections and compact output files with fast turn-around time.

• Progen™, a revolutionary lithography model development tool, enables users to create models of virtually any form and fit them to empirical data. The results are compact, efficient models used by the Proteus correction engine.
• Prospector™, an interactive visualization and analysis tool through which the interactions of models and patterns can be explored, measured, collated and exported for use by other tools.

Original pattern

Moderate correction

Aggressive correction

Notching effect correction.

Selective correction.

Proteus Correction Processor
Optical Proximity Correction (OPC) plays an increasingly critical role in enabling optical lithography to keep pace with shrinking chip dimensions. Proteus enhances yield and enables the continued evolution toward ultra deep sub-micron designs by modifying layout geometries for systematic distortions introduced during fabrication. Extensive programmability ensures that Proteus can be adapted to accommodate virtually any type of optical proximity effect or other distortions arising from resist, etch and underlying topography influences.

Programmable Correction Fidelity
In two dimensional configurations, a perfect correction would require continuously varying biases on features. To address trade-offs between correction fidelity and mask fabrication constraints, such as pattern grid and file size, the user is provided a number of options to control correction aggressiveness, granularity and tolerance. Treatments applied to corners, line-ends and other two-dimensional structures can be fully customized with the recipe control scripting language.

Multiple Layer Handling
Corrections involving influences from several masking layers can be handled in a number of ways. One method is to use figures in reference layers to select regions to correct. In advanced applications, reference levels can be used to model underlying topography for substrate-based correction.

Distributed Processing
Proteus supports distributed network processing for fast turn-around time. By distributing the task among several platforms, cycle times can be shortened to meet your requirements. Excellent scalability has been achieved on more than 100 processors.

Correction applied to pattern by modifying existing geometries and adding non-printing auxiliary features.
Design rules can be checked during correction.	Correction jobs are controlled via a straightforward user interface. (click to view larger image)

Engineered Mask Techniques
Proteus offers extensive support for a variety of engineered mask techniques. Auxiliary features can be placed in the corrected pattern using the recipe scripting language. These can be used as subresolution assist features, for customized serif or end-cap shapes, or for loadbalancing applications.

Proteus also supports corrections for many phase-shift mask (PSM) strategies. Correction can simultaneously modify phase and chrome masking layers.

Flexible User Interface
Several layers of programmability provide Proteus users the maximum degree of control over all aspects of the correction process, while at the same time preserving a simple user interface. In-depth recipe customization can be performed by directly modifying the recipe scripts. The recipe scripting language is linked to a configurable graphical user interface so that recipes and user-customized scripts can present a concise set of controls to non-expert users.

Design Rule Conformance
Mask design rules can be checked during correction to ensure that corrected mask patterns meet your mask fabrication requirements.

Correction applied to pattern by modifying existing geometries and adding non-printing auxiliary features. United States Patent Numbers 5,242,770 and 5,447,810 claim certain aspects of the use of Auxiliary Features to address proximity effects and depth of focus issues. The patents are assigned to ASML MaskTools, Inc. and, as with all patents, are presumed valid pursuant to U.S.C. $ 282.

Progen - Model Development Tool

ProGen provides automated tools for fitting models to empirical data.
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Progen builds the behavior models used by the OPC engine for proximity correction and by Prospector for lithography simulation. Progen's integrated environment supports:

• The IC community's commonly used empirical model forms.
• A framework for defining and testing new model forms using a general model expression language.
• Spreadsheet-like data management for defining an empirical test suite and modeling all test point configurations automatically.
• Regression tools that optimize model parameters to fit empirical data using user-defined cost functions.
• Visualization and plotting tools for direct analysis of model characteristics, CD behaviors and statistical fits.
• Conversion of models to a compact, efficient representation for seamless transfer to other Synopsys Mask Synthesis tools.

Prospector - Visualization and Analysis

ProGen models are defined using easy-to-read templates.
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Prospector is an interactive simulation and analysis tool that is closely integrated with the other OPC modules. High-speed wafer image simulation, based on Progen models, supports many proximity effect visualization and analysis functions. Prospector interactively provides qualitative and quantitative information on wafer imaging characteristics under alternative recipe parameter and process conditions.

Prospector Helps You: