OPC Mask Design for Semiconductor Pattern Distortion
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Solution Overview
Problem
As semiconductor devices become highly integrated, the optical proximity effect leads to pattern distortion during the lithography process, causing defects due to the influence of diffraction and interference of light, which existing methods fail to accurately correct and verify.
Innovation Solution
The method involves performing optical proximity correction (OPC) on a mask design by measuring line widths, obtaining probability distributions, and comparing them with critical probabilities to determine if further correction is needed, ensuring the OPC rule check is conducted to verify the accuracy and reliability of the pattern transfer onto a wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If optical proximity correction (OPC) is performed on mask design to correct pattern distortion, then manufacturing precision is improved, but device complexity increases due to multiple correction iterations and probability distribution calculations
Solution Approach 1:
The patent performs preliminary OPC corrections and probability distribution calculations before final mask fabrication. By conducting multiple correction iterations and analyzing line width probability distributions in advance, the method predicts potential defects and adjusts the mask design proactively, ensuring high pattern transfer accuracy while systematically managing the complexity through structured preliminary analysis steps
Solution Approach 2:
The patent implements a feedback mechanism where probability distributions of line widths are calculated and compared against critical thresholds. If the probability of line widths falling within critical ranges exceeds acceptable limits, the OPC process automatically iterates with adjusted parameters. This closed-loop feedback system continuously refines the mask design to optimize pattern accuracy while providing controlled management of process complexity
2Reliability
If multiple OPC iterations are performed to ensure pattern accuracy, then reliability is improved, but productivity decreases due to extended processing time
Solution Approach 1:
The patent applies partial OPC iterations by performing corrections only on critical pattern regions where optical proximity effects are most pronounced. Instead of uniformly processing all patterns through multiple full OPC cycles, the method selectively applies corrections based on probability distribution analysis of line widths, achieving reliable defect prediction for critical areas while reducing overall processing time and maintaining acceptable productivity
Solution Approach 2:
The patent dynamically adjusts OPC parameters such as correction amounts and iteration counts based on the calculated probability distributions of line widths. When probability values indicate low risk of defects, the process reduces the number of iterations or skips corrections for non-critical patterns. This adaptive parameter adjustment maintains high reliability for critical patterns while improving overall mask fabrication throughput by avoiding unnecessary processing steps
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 accuracy and reliability of the OPC process by predicting and preventing defects, ensuring that the pattern formed on the wafer matches the intended design, even as integration density increases.
Implementation Method 1
the optical proximity effect leads to pattern distortion during the lithography process, causing defects due to the influence of diffraction and interference of light
Implementation Method 2
the optical proximity effect leads to pattern distortion during the lithography process, causing defects due to the influence of diffraction and interference of light
Data Source
AI summary
A method includes performing OPC on a first mask design having a plurality of patterns having line widths; measuring a number of each of the line widths within the first mask design on which the OPC was performed; obtaining a probability distribution of each of the line widths within the first mask design on which the OPC was performed; obtaining a distribution of each of the line widths by multiplying the number of each of the line widths by the probability distribution; obtaining a line width distribution of the first mask design by summing the distribution of each of the line widths; comparing a probability distribution within a first critical line width in the line width distribution with a first critical probability; and performing the OPC on the first mask design again if the probability distribution within the first critical line width is greater than the first critical probability.