Semiconductor Mask OPC Layout Correction for Dense Pattern Printing
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Solution Overview
Problem
As semiconductor integration density increases, the proximity of image patterns on masks leads to significant light interference and diffraction, resulting in distorted layouts during photolithography processes, which existing resolution enhancement technologies like OPC struggle to adequately address.
Innovation Solution
A method involving optical proximity correction (OPC) is employed to generate a target curve using bias control points, iteratively updating design masks to minimize distortions by adjusting the mask patterns through multiple OPC processes, ensuring precise layout transfer onto the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If image patterns are placed closer together to increase integration density, then productivity is improved, but light interference and diffraction increase causing layout distortion
Solution Approach 1:
The patent applies optical proximity correction (OPC) to pre-distort the mask patterns before photolithography. By calculating and applying bias values to pattern contours in advance, the mask compensates for expected light interference and diffraction effects, ensuring that the final printed layout matches the desired pattern even when patterns are closely spaced
Solution Approach 2:
The patent modifies geometric parameters of the mask patterns by applying bias values to contour lines. The bias value adjusts the distance between pattern edges and feature boundaries, changing the physical dimensions of mask features to compensate for optical effects during photolithography
2Manufacturing precision
If optical proximity correction is applied to reduce light interference, then manufacturing precision is improved, but the fabrication process becomes more complex
Solution Approach 1:
The patent divides the OPC process into discrete steps: extracting contour lines from patterns, calculating bias values for each contour, applying biases to generate corrected patterns, and iteratively refining results. This segmentation makes the complex OPC process more manageable and implementable
Solution Approach 2:
The patent employs iterative OPC where the corrected patterns are evaluated, and bias values are adjusted based on the difference between desired and actual patterns. This feedback mechanism continuously refines the mask design to achieve the target layout accuracy
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 light interference and diffraction, enabling accurate printing of desired layouts on semiconductor wafers, thereby improving the fabrication of semiconductor devices by minimizing defects and ensuring functional integrity.
Implementation Method 1
the interference and diffraction of light are highly likely to occur
Implementation Method 2
the interference and diffraction of light are highly likely to occur
Data Source
AI summary
A method of fabricating a mask by performing optical proximity correction (OPC) is provided. The method of fabricating a mask includes generating a target curve by using bias control points, extracting a first contour of an initial design mask by performing an OPC process, generating a first updated design mask, which is obtained by updating the initial design mask, by using the first contour and the target curve, extracting a second contour of the first updated design mask by performing the OPC process, and generating a second updated design mask by using the second contour and the target curve.