DMD Column Masking for Lithography Line Edge Roughness
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Solution Overview
Problem
Current photolithography techniques face challenges in creating precise and cost-effective patterns on large area substrates, particularly in correcting non-uniform patterns, which leads to line edge roughness issues in semiconductor and display device manufacturing.
Innovation Solution
A software application platform that utilizes a digital micromirror device (DMD) with multiple columns of mirrors, where at least one entire column is disabled, and the substrate is translated in steps to expose it to electromagnetic radiation, iteratively ensuring uniform pattern correction across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional photolithography techniques are used to create patterns on large area substrates, then manufacturing cost is reduced, but line edge roughness increases and pattern uniformity deteriorates
Solution Approach 1:
The patent segments the exposure process into multiple sequential shots instead of exposing the entire substrate in one shot. The substrate is divided into multiple exposure regions that are exposed iteratively, with each shot covering a portion of the substrate. This segmentation allows for better control of exposure parameters and reduces line edge roughness by avoiding the harmful effects of single-shot exposure across large areas.
Solution Approach 2:
The patent introduces dynamic adjustment of exposure parameters between shots. The system dynamically modifies exposure conditions (such as exposure dose, scan speed, or mirror positioning) for each subsequent shot based on the previous shot's results. This dynamic adjustment enables real-time correction of pattern uniformity issues and reduction of line edge roughness throughout the exposure process.
2Productivity
If multiple columns of mirrors in DMD are all enabled for exposure, then exposure speed increases, but pattern uniformity deteriorates due to non-uniform illumination
Solution Approach 1:
The patent applies local quality by selectively enabling or disabling specific columns of mirrors in the DMD device for each exposure shot. Instead of uniformly enabling all columns, the system adjusts which columns are active based on the specific exposure requirements of different substrate regions. This local adjustment ensures uniform illumination patterns while maintaining efficient exposure speed across the entire substrate.
3Loss of time
If the entire substrate is exposed in a single shot, then processing time is reduced, but line edge roughness increases due to non-uniform exposure effects
Solution Approach 1:
The patent employs periodic action by dividing the exposure process into multiple periodic shots rather than a single continuous exposure. Each shot is a discrete exposure event with controlled duration and parameters, repeated sequentially across different substrate regions. This periodic exposure approach maintains reasonable processing time while significantly reducing line edge roughness compared to single-shot exposure.
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 corrects non-uniform image patterns and reduces line edge roughness, enhancing the precision and efficiency of pattern creation on substrates, thereby addressing the need for improved maskless lithography techniques.
Implementation Method 1
a light-sensitive photoresist is typically applied to at least one surface of the substrate. Then, a pattern generator exposes selected areas of the light-sensitive photoresist as part of a pattern with light to cause chemical changes to the photoresist
Implementation Method 2
in a digital micromirror device (DMD) installed in an image projection system, the DMD having a plurality of columns, each column having a plurality of mirrors
Data Source
AI summary
An image correction application relating to the ability to apply maskless lithography patterns to a substrate in a manufacturing process is disclosed. The embodiments described herein relate to a software application platform, which corrects non-uniform image patterns on a substrate. The application platform method includes in a digital micromirror device (DMD) installed in an image projection system, the DMD having a plurality of columns, each column having a plurality of mirrors, disabling at least one entire column of the plurality of columns, exposing a first portion of the substrate to a first shot of electromagnetic radiation, exposing a second portion of the substrate to a second shot of electromagnetic radiation, and iteratively translating the substrate a step size and exposing another portion of the substrate to another shot of electromagnetic radiation until the substrate has been completely exposed to shots of electromagnetic radiation.