Spin-Coating Optical Feedback for Resist Thickness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing apparatus struggle to accurately and efficiently control resist layer thickness during mass production, which is critical for achieving precise critical dimensions in semiconductor circuits.
Innovation Solution
A spin-coating apparatus equipped with an optical detector that measures resist layer thickness in-situ by correlating light intensity with resist layer thickness using polynomial functions, allowing for real-time feedback to adjust spin-coating process conditions such as spin speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spin coating is used to deposit resist layer, then deposition efficiency is improved, but manufacturing precision of resist layer thickness deteriorates
Solution Approach 1:
The patent implements real-time optical detection during spin coating to measure resist layer thickness, with the measurement signal fed back to the control system to dynamically adjust spin speed and maintain target thickness. This closed-loop feedback mechanism resolves the contradiction by enabling high-speed deposition while maintaining precise thickness control through continuous monitoring and adjustment.
Solution Approach 2:
The patent replaces traditional mechanical thickness measurement methods with optical detection. An optical detector measures the reflected light intensity from the resist layer surface, which correlates to thickness, eliminating the need for physical contact or post-processing measurements. This substitution enables real-time monitoring during high-speed spin coating without compromising either productivity or precision.
2Manufacturing precision
If multiple processing parameters are varied to optimize critical dimensions, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent uses real-time optical feedback to directly control resist layer thickness, eliminating the need to manually optimize multiple interdependent parameters such as resist material composition, radiation dose, and development time. The feedback system automatically adjusts spin speed based on measured thickness, simplifying the overall process while maintaining precise critical dimension control.
Solution Approach 2:
The patent changes the primary control parameter from a combination of multiple process variables (resist composition, radiation dose, development time) to a single dominant parameter: spin speed, which is directly controlled by the optical feedback system. This parameter simplification reduces device complexity while maintaining manufacturing precision through direct thickness control.
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 enables precise control of resist layer thickness, improving the uniformity of critical dimensions and integrating seamlessly into existing semiconductor fabrication processes.
Implementation Method 1
illuminating at least one region of the material layer with a light; recording strength of the light reflected from the at least one region
Data Source
AI summary
A method, comprising forming a material layer over a substrate; illuminating at least one region of the material layer with a light; recording strength of the light reflected from the at least one region; and determining a thickness of the material layer in the at least one region according to the strength of the light.