Shallow Ion Implanting OPC Method for Poly-Silicon Contact Regions
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Solution Overview
Problem
Conventional Optical Proximity Correction (OPC) methods for shallow ion implanting layers face challenges in compensating for pattern distortions due to reflective influences from front layers, leading to errors and inefficiencies, particularly when pattern intervals are small, resulting in photoresist collapse and increased processing complexity.
Innovation Solution
An OPC method that selectively identifies and eliminates invalid pattern regions in shallow ion implanting layers by extending poly-silicon contacting regions and performing model-based OPC corrections, thereby simplifying the processing and reducing the risk of process problems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional OPC routine is performed on all patterns in shallow ion implanting layer, then pattern distortion compensation is attempted, but calculation resource is wasted on invalid patterns and processing time is prolonged
Solution Approach 1:
The patent extracts and removes invalid pattern structures (those falling on STI regions or outside shallow ion implanting regions) from the OPC processing scope. By identifying patterns that do not require correction and excluding them from the OPC routine, the calculation resources are concentrated on valid patterns only, thereby reducing overall processing time while maintaining compensation accuracy for patterns that actually need it.
Solution Approach 2:
The patent segments the shallow ion implanting layer patterns into valid and invalid categories based on their spatial relationship with device regions and contact holes. This segmentation allows differential processing where only valid patterns undergo OPC correction, while invalid patterns are excluded from the correction process, optimizing resource allocation and processing efficiency.
2Manufacturing precision
If OPC routine processes all pattern structures including those on STI, then comprehensive correction is attempted, but complexity of OPC routine increases and calculation resources are wasted
Solution Approach 1:
The patent extracts invalid pattern structures that fall on STI (shallow trench isolation) regions or outside the shallow ion implanting regions and removes them from the OPC processing scope. This extraction reduces the number of patterns requiring correction, thereby simplifying the OPC routine complexity and reducing calculation resource requirements while maintaining correction completeness for valid patterns.
Solution Approach 2:
The patent applies different processing treatments to different regions: valid patterns within shallow ion implanting regions undergo full OPC correction, while invalid patterns on STI or outside implanting regions are excluded from correction. This local differentiation optimizes the balance between correction completeness and processing complexity by applying correction only where necessary.
3Productivity
If pattern interval is small (less than 1.5-3 times minimum size), then layout density is high, but hot spots form and photoresist collapse occurs
Solution Approach 1:
The patent performs preliminary identification and special handling of potential hot spot regions where pattern intervals are smaller than 1.5-3 times the minimum size. By detecting these high-risk areas before the main OPC processing and applying targeted corrections or adjustments, the method prevents photoresist collapse and maintains reliability while preserving high layout density in valid regions.
4Manufacturing precision
If reflected light from front layer is considered in OPC, then pattern distortion compensation is attempted, but amount of wafer data collected becomes huge making correction difficult
Solution Approach 1:
The patent extracts and excludes invalid pattern structures from the set of patterns requiring OPC correction. By removing patterns that fall on STI regions or outside shallow ion implanting regions, the amount of wafer data that needs to be processed and corrected is significantly reduced, making the reflection-based distortion compensation more manageable while maintaining accuracy for valid patterns.
Data Source
AI summary
The present invention discloses an OPC method for a shallow ion implanting layer, comprising the following steps of: selecting a valid device region in an implanting active region in a shallow ion implanting original layout; selecting a region in the valid device region which is contacted with a poly-silicon pattern in a poly-silicon layer, as a poly-silicon contacting region; extending the length and width of the poly-silicon contacting region and the non poly-silicon contacting region, to form a new poly-silicon contacting region and a new non poly-silicon contacting region; combining a gap portion which an interval between any two new poly-silicon contacting regions and/or new non poly-silicon contacting regions after extending is smaller than or equal to G and completely fallen in the STI region, with the poly-silicon contacting regions and non poly-silicon contacting regions after extending, to form a correction target layer; performing a model-based OPC routine on the correction target layer, to obtain a mask layer.