Lithography Distortion Correction via Measured Model Inversion
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Solution Overview
Problem
Lithography processes for semiconductor and display device manufacturing face significant distortion errors in wafers and application panels, which accumulate and worsen across layers, and are exacerbated by environmental heat and stress.
Innovation Solution
A method is introduced to measure and correct distortion by creating a distortion model based on the differences between actual and designed feature locations, using digital micro-mirror devices to adjust light projection, and combining correction models for global alignment, accounting for plate shift and rotation across multiple layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple layers are printed and processed sequentially, then device functionality is achieved, but distortion errors accumulate and worsen across layers
Solution Approach 1:
The patent applies preliminary distortion correction by creating correction models from measured distortion data obtained from previous layers. These correction models are then applied in advance to subsequent layers before printing, preventing distortion accumulation rather than correcting it after the fact. This is evident in the iterative process where distortion measurements from layer N are used to generate correction models for layer N+1.
Solution Approach 2:
The patent implements a feedback mechanism where distortion is measured after each layer processing, and this measurement feeds into creating correction models for the next layer. The system continuously monitors pattern placement errors and uses this information to adjust and correct distortion in subsequent layers, forming a closed-loop control system that progressively improves alignment accuracy.
2Manufacturing precision
If distortion correction models are created for each section, then local precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the substrate into multiple sections or regions, each with its own distortion correction model. This segmentation allows local distortion characteristics to be captured and corrected independently for each region, improving local precision. The system creates section-specific correction models based on measured distortion data from each region, rather than applying a single global correction model.
Solution Approach 2:
The patent applies local quality by creating distortion correction models that are specific to different regions of the substrate. Each section receives a customized correction model tailored to its local distortion characteristics, allowing the system to address region-specific distortion patterns with appropriate correction strategies rather than using a uniform approach.
3Measurement precision
If multiple measurements and correction iterations are performed, then distortion accuracy is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary distortion measurements and creates correction models in advance before final production printing. By establishing correction models from initial measurements and applying them proactively to subsequent layers, the system reduces the need for repeated measurement-correction cycles during production, thereby improving efficiency while maintaining accuracy.
Solution Approach 2:
The patent implements an iterative feedback process where distortion is measured, correction models are generated, and corrections are applied. This feedback loop continues until distortion is reduced to acceptable levels, allowing the system to balance measurement precision with processing efficiency by stopping iterations when sufficient correction is achieved.
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 effectively reduces distortion errors by accurately aligning and printing layers, improving the precision of pattern placement and reducing residual distortions, even in complex substrate geometries.
Implementation Method 1
using digital micro-mirror devices to adjust light projection
Data Source
AI summary
Methods and systems are provided that, in some embodiments, print and process a layer. The layer can be on a wafer or on an application panel. Thereafter, locations of the features that were actually printed and processed are measured. Based upon differences between the measured differences and designed locations for those features at least one distortion model is created. Each distortion model is inverted to create a corresponding correction model. When there are multiple sections, a distortion model and a correction model can be created for each section. Multiple correction models can be combined to create a global correction model.