Substrate Region Partitioning for Uniform Semiconductor Pattern Development
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Solution Overview
Problem
Conventional substrate processing methods for semiconductor and liquid crystal devices face challenges in achieving uniform in-plane development accuracy due to non-uniform chemical discharge and dissolution products distribution, leading to pattern dimension variations and development inhibition effects.
Innovation Solution
A pattern forming method that involves forming a resist film on a substrate, exposing it to create a latent image, and developing it by flowing a solution while partitioning the substrate into regions to determine correction exposure doses based on pattern opening ratios, ensuring actual pattern dimensions match design dimensions, and using the resist pattern as a mask for etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional spray method is used to supply chemical onto a rotating substrate, then the substrate can be processed, but the discharge pressure and supply amount of chemical cannot be uniform across central and peripheral portions, resulting in poor in-plane development accuracy
Solution Approach 1:
The substrate surface is divided into multiple regions (first region and second region) with different exposure doses. The first region receives a larger exposure dose while the second region receives a smaller exposure dose, compensating for the non-uniform chemical supply and dissolution product distribution across the substrate plane.
Solution Approach 2:
Different exposure doses are applied to different regions of the substrate based on their specific requirements. The central region (first region) receives a different dose than the peripheral region (second region), optimizing pattern dimensions locally for each area to achieve overall uniformity.
2Manufacturing precision
If substrate rotation is used during development, then processing can be performed, but dissolution products are distributed non-uniformly on the substrate due to centrifugal forces, making it difficult to obtain uniform in-plane process accuracy
Solution Approach 1:
The exposure dose is pre-adjusted for different regions before development occurs. By calculating and applying different exposure doses to different regions in advance, the patent compensates for the anticipated non-uniform dissolution product distribution caused by substrate rotation and centrifugal forces.
Solution Approach 2:
The patent uses a correction exposure dose determination process that considers the pattern opening ratio and upstream/downstream region relationships to calculate the appropriate exposure dose for each region, effectively feedback-adjusting for the non-uniform conditions created by substrate rotation.
3Manufacturing precision
If correction exposure dose is determined based on pattern opening ratio and upstream region patterns, then actual pattern dimensions can match design dimensions, but the process complexity increases due to region partitioning and calculation requirements
Solution Approach 1:
The patent changes the exposure dose parameter based on the pattern opening ratio and the patterns in upstream regions. By systematically varying this key parameter across different regions, the patent achieves accurate pattern dimensions while managing complexity through a structured approach.
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 method effectively reduces pattern dimension variations and improves in-plane uniformity by correcting exposure doses, resulting in higher accuracy and reduced CD variations, as demonstrated by a three sigma value of 4.8 nm compared to 5.3 nm without correction.
Implementation Method 1
developing the resist film by flowing a developing solution on the resist film to form a resist pattern
Implementation Method 2
exposing the resist film to form a latent image of pattern on the resist film
Data Source
AI summary
A pattern forming method includes developing a resist film on a main surface of a substrate by flowing a developing solution on the film to form a resist pattern, the developing the film including partitioning the surface into M (≧2) regions and determining correction exposure dose for each of the M region, the determining the correction exposure dose including determining a correction exposure dose for an i-th (1≦i≦M) region so that an actual pattern dimension of a pattern on the i-th region matches a design pattern dimension based on a pattern opening ratio of a pattern to be formed on the substrate, the pattern being located on a region which is further upstream region than the i-th region with respect to an upstream direction of a flow of the solution, and forming the pattern by etching the substrate using the resist pattern as a mask.