Substrate-Specific OPC Models for Gate Photomask Dimension Control

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Solution Overview

Problem

Traditional Optical Proximity Correction (OPC) methods for photomask patterns in semiconductor manufacturing are inadequate as they fail to accurately account for differences in optical effects across various substrates, leading to errors in gate dimension control, especially in advanced integrated circuit technologies below 65 nm, where slight substrate variations affect photolithography performance.

Innovation Solution

A method is developed to create separate optical proximity effect models for active area and shallow-trench isolation substrates, allowing for individual OPC corrections to the gate photomask patterns on each, thereby reducing errors by 4% and improving dimension control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single OPC model based on Active Area is used for all gate photomask patterns, then the manufacturing process is simple, but spacing dimension errors occur when photolithography exposure conditions vary

Engineering Contradiction:
ImproveOPC process simplicityVSAvoidgate spacing dimension accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent segments the gate photomask patterns into two distinct categories: those on Active Area substrates and those on Shallow-trench isolation substrates. Separate OPC models are created for each substrate type, allowing each model to be optimized for its specific substrate characteristics. This segmentation resolves the contradiction by maintaining process simplicity through automated classification while achieving high precision through substrate-specific correction models.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by creating specialized OPC models tailored to each substrate type's unique optical characteristics. The Active Area model and Shallow-trench isolation model have different parameters and correction rules optimized for their respective substrate properties. This allows each local region (substrate type) to receive appropriately optimized correction, resolving the contradiction between unified simple processing and location-specific precision requirements.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If separate OPC models are created for Active Area and Shallow-trench isolation substrates, then spacing dimension accuracy improves, but device complexity increases

Engineering Contradiction:
Improvegate spacing dimension accuracyVSAvoidOPC model complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent manages complexity by segmenting the problem into two distinct, well-defined substrate types with dedicated models. Rather than creating a single complex model attempting to handle all variations, the segmentation approach creates two simpler, specialized models. The automated classification system routes patterns to the appropriate model, preventing the need for complex decision-making within each model itself.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a universal OPC processing framework that can handle multiple substrate types through a single integrated system. The classification mechanism and processing pipeline are designed to work with both Active Area and Shallow-trench isolation models uniformly. This universality reduces overall system complexity by providing a consistent interface and workflow, despite the presence of multiple specialized models.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS8434034B2Method of making optical proximity correction to original gate photomask pattern based on different substrate areas
Publication Date: 2013.04.30 SHANGHAI HUALI MICROELECTRONICS CORP
  • US8434034B2 patent drawing
  • US8434034B2 patent drawing
  • US8434034B2 patent drawing

AI summary

The present invention relates to the field of semiconductor manufacturing, and particularly to a method of making Optical Proximity Correction to an original gate photomask pattern based on different substrate areas. The present invention discloses a method of making OPC to an original gate photomask pattern based on different substrate areas, which makes correction to gate photomask pattern dimension on the AA and to gate photomask pattern dimension on the STI respectively by creating two different optical proximity effect models of the gate, so as to control the finally imaged gate photomask pattern dimensions more accurately; moreover, the error of the correction result of the gate spacing dimension on the STI can be reduced by 4% by separating the patterns and using the gate model based on the STI, so as to avoid the spacing dimension error when the photolithography exposure conditions vary.