Pattern Match Optical Proximity Correction for IC Layout
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in accurately producing small circuit features during photolithography, where optical proximity effects cause line width variations and distortions, leading to inconsistent circuit component operation and potential connection failures, which are difficult to detect and correct due to the complexity of Optical Proximity Correction (OPC) processes.
Innovation Solution
A method is introduced that involves storing distinct defect and OPC patterns in libraries, identifying and modifying circuit layouts to correct optical proximity effects by applying post-OPC targets, thereby simplifying the OPC process and reducing the ripple effect, data expansion, and enabling efficient distributed computing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional OPC methods are used to correct optical proximity effects, then manufacturing precision is improved, but device complexity and processing time increase significantly
Solution Approach 1:
The patent transforms the complex OPC process into a parameter-driven approach by defining specific parameters (hammerhead width, serif size, compensation amounts) that can be adjusted based on pattern type and optical proximity conditions. This allows systematic correction of manufacturing distortions while maintaining process manageability through parameter optimization rather than complex geometric manipulation.
Solution Approach 2:
The patent segments the OPC process into distinct pattern categories (isolated lines, dense lines, contact holes, vias) with specific correction rules for each segment. This segmentation allows targeted application of appropriate correction techniques to different pattern types, reducing overall process complexity while maintaining precision for each pattern category.
2Manufacturing precision
If comprehensive OPC is applied to all circuit features, then manufacturing precision is improved, but processing time and computational resources increase
Solution Approach 1:
The patent applies OPC selectively to pattern types that exhibit significant optical proximity effects (such as dense lines and isolated features) while using simplified or no correction for patterns that are less sensitive. This partial action approach maintains manufacturing precision for critical patterns while reducing overall processing time by avoiding exhaustive correction of all circuit features.
3Manufacturing precision
If OPC corrections are applied to compensate for optical proximity effects, then manufacturing precision is improved, but the process requires sophisticated software and increases operational complexity
Solution Approach 1:
The patent establishes a parameter-based OPC system where correction amounts, hammerhead dimensions, and serif characteristics are defined as adjustable parameters tied to specific pattern types and optical conditions. This parameterization enables implementation through standardized software routines that automatically select and apply appropriate parameters based on pattern recognition, significantly improving ease of operation while maintaining high pattern fidelity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves the efficiency and consistency of OPC by using pattern-based methodologies, minimizing the ripple effect, reducing data processing, and enabling faster convergence and predictable results, while allowing for design independence and efficient distributed computing.
Implementation Method 1
The photo-resist is then exposed through a photolithography exposure tool called stepper or scanner to a radiation source with wavelength in DUV range that changes the solubility of the photo-resist at areas exposed to the radiation
Implementation Method 2
The photo mask, which contains circuit layout information, consists of a patterned material or materials that interact with the exposing radiation through intensity and/or phase modulation
Data Source
AI summary
A method for applying optical proximity correction (OPC) to a circuit layout, includes storing distinct defect patterns in a defect pattern library and modifying the circuit layout to fix defect pattern. The method also includes storing a distinct patterns in an OPC pattern library storing one or more post-OPC targets in association with one of distinct patterns in the OPC pattern library, wherein the one or more post-OPC targets are configured to correct optical proximity effects of the associated distinct pattern. The method further includes identifying in the circuit layout a pattern that has substantially the same optical proximity environment as the one of the distinct patterns in the OPC pattern library; and applying OPC to the identified pattern using the one or more post-OPC targets associated with the one of the distinct pattern in the OPC pattern library.