Double Exposure Mask Set for Comb Pattern Decomposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional double exposure lithography methods face issues such as film punching problems and inconsistent corner rounding profiles due to the decomposition of comb patterns, leading to potential leakage and overlay issues in the deep submicron domain.
Innovation Solution
A novel mask set and method for decomposing a single comb mask pattern into two sub-mask patterns with specific features, where the second mask's base overlaps the first mask's base, and teeth are arranged to ensure regular spacing and protruding portions for improved corner rounding and reduced overlay regions, facilitating a double exposure process that addresses these issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional double exposure lithography decomposes comb patterns into two separate patterns, then the pattern density is increased, but film punching problems and inconsistent corner rounding profiles occur
Solution Approach 1:
The patent divides the single comb pattern into two separate comb patterns (first comb pattern and second comb pattern) for double exposure lithography. Each comb pattern contains teeth with specific pitch relationships to the original pattern, enabling increased pattern density while maintaining manufacturing precision through controlled segmentation of the exposure process
Solution Approach 2:
The patent applies different pitch relationships to different regions of the comb patterns. The first comb pattern has teeth with pitch P1, and the second comb pattern has teeth with pitch P2, where P1 and P2 are specifically related to the original pitch P. This local differentiation in pitch design ensures consistent corner rounding profiles at intersection positions while achieving the desired pattern density
2Quantity of substance
If conventional double exposure lithography decomposes comb patterns, then higher pattern density is achieved, but overlay regions suffer from film punching problems
Solution Approach 1:
The patent changes the pitch parameters of the decomposed comb patterns to specific relationships with the original pitch P (P1 and P2 are specifically related to P). This parameter adjustment optimizes the overlay region characteristics, preventing film punching problems while maintaining the benefits of increased pattern density through double exposure
3Device complexity
If perpendicular intersection of decomposed patterns is used, then the double exposure process is simplified, but corner rounding features are lost leading to leakage issues
Solution Approach 1:
The patent applies different pitch relationships to different regions of the comb patterns. The first comb pattern has teeth with pitch P1, and the second comb pattern has teeth with pitch P2, where P1 and P2 are specifically related to the original pitch P. This local differentiation ensures consistent corner rounding profiles at intersection positions while maintaining a relatively simple double exposure process
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
The solution effectively prevents film punching and leakage issues by ensuring rounded corner profiles and reduced overlay regions, enhancing the resolution and symmetry of the resulting photoresist patterns, thereby improving the double exposure process in the deep submicron domain.
Implementation Method 1
The images of the patterned photo-mask are projected through the high-precision optical system onto the wafer surface, which is coated with a layer of light-sensitive chemical compound, e.g. photo-resist. The patterns are then formed on the wafer surface after complex chemical reactions
Data Source
AI summary
A mask set for double exposure process and method of using said mask set. The mask set is provided with a first mask pattern having a first base and a plurality of first teeth and protruding portions, and a second mask pattern having a second base and a plurality of second teeth, wherein the second base may at least partially overlap the first base such that each of the protruding portions at least partially overlaps one of the second teeth.