Optical Proximity Correction Using Virtual Targets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor device fabrication progresses, the miniaturization of patterns leads to distortions and deviations in reproduced patterns due to light interference and processing effects, causing improper pattern reproduction and increased costs due to reduced yield.
Innovation Solution
A system and method using adjustment patterns and physical parameters to control mask structure dimensions through optical proximity correction, where sacrificial patterns are selected and processed to determine optimal locations, reducing computational effort and memory usage by focusing on local environments and virtual targets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If optical lithography is used to reproduce patterns, then the fabrication process can be automated and scaled, but distortions and deviations occur in the reproduced patterns due to light interference and processing effects
Solution Approach 1:
The patent applies preliminary action by performing optical proximity correction on the mask pattern before lithography exposure. The system pre-calculates and applies adjustment patterns to compensate for known distortions, so that when the corrected mask is exposed, the final reproduced pattern matches the intended design specifications without requiring post-processing corrections.
Solution Approach 2:
The system incorporates feedback by using measured or simulated distortion data from previous lithography processes to inform the correction algorithm. The optical proximity correction tool uses feedback about actual pattern reproduction deviations to iteratively adjust the mask pattern, ensuring that the corrected pattern produces the desired final geometry after lithography.
2Productivity
If the dimensions of structures are made smaller to increase device density, then more devices can be packed into a substrate, but the structures become smaller than the wavelength of light used in optical lithography, causing interference effects and distortions
Solution Approach 1:
The patent applies preliminary action by performing optical proximity correction on the mask pattern before lithography exposure. The system pre-calculates and applies adjustment patterns to compensate for known distortions, so that when the corrected mask is exposed, the final reproduced pattern matches the intended design specifications without requiring post-processing corrections.
Solution Approach 2:
The system changes the geometric parameters of the mask pattern structures through optical proximity correction. By adjusting the dimensions, positions, and shapes of mask features based on calculated distortion models, the system compensates for light wavelength limitations and ensures that the final pattern dimensions match the intended small features even when they are smaller than the light wavelength.
3Manufacturing precision
If optical proximity correction is performed using traditional methods, then pattern reproduction accuracy can be improved, but computational effort and memory usage increase significantly
Solution Approach 1:
The patent applies segmentation by dividing the complex optical proximity correction problem into smaller, manageable regions. The system processes the mask pattern in discrete segments or zones, applying correction algorithms locally to each region rather than attempting to correct the entire pattern at once. This segmentation reduces the computational complexity and memory requirements while maintaining overall pattern reproduction accuracy.
Solution Approach 2:
The system applies local quality by tailoring the optical proximity correction adjustments to specific local regions of the mask pattern based on their unique distortion characteristics. Rather than applying a uniform correction approach, the system analyzes and corrects each local area according to its specific geometric features and expected distortion behavior, optimizing accuracy while reducing overall computational burden.
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 significantly reduces runtime and memory requirements, allowing for more efficient optical proximity correction and improved pattern reproduction accuracy, thereby enhancing the semiconductor fabrication process.
Implementation Method 1
as the dimensions of the structures making up the patterns continue to become smaller, their sizes approach (in some cases, the dimensions of the structures are smaller than) the wavelength of the light used in optical lithography, and the interference and processing effects can cause distortions and deviations in the patterns as they are reproduced onto the semiconductor substrate
Data Source
AI summary
System and method for using adjustment patterns as well as physical parameters as targets to control mask structure dimensions using optical proximity correction. A method for correcting layer patterns comprises selecting optimum sacrificial patterns, defining virtual targets from the optimum sacrificial patterns, and executing an optical proximity correction process with the virtual targets to correct layer patterns. The selecting of the optimum sacrificial patterns may be performed in a separate processing stage, thereby reducing the number of targets to be investigated during a process window optical proximity correction, thereby reducing the runtime, processing, and memory requirements.