Photoresist Layer Absorption Gradient for High-Resolution Patterning
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Solution Overview
Problem
The photolithography process in semiconductor manufacturing faces challenges in achieving high precision and resolution due to undesired shape formation at the top of the photoresist pattern, which is influenced by variations in light absorption rates within the photoresist layer.
Innovation Solution
A method is employed to form a photoresist layer with distinct parts having different light absorption rates, where a first part with lower absorption is processed to allow precise exposure and removal, while a second part with higher absorption forms the pattern, ensuring high resolution and avoiding top shape issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform photoresist layer is used for exposure, then the exposure process is simple, but the top part of the photoresist pattern forms undesired shape due to light absorption variations
Solution Approach 1:
The photoresist layer is designed with different light absorption characteristics in different regions: the bottom part (close to target layer) has higher light absorption rate while the top part (away from target layer) has lower light absorption rate. This local differentiation resolves the contradiction by enabling precise pattern formation at the critical bottom interface while maintaining processability at the top surface.
2Measurement precision
If the photoresist layer has high light absorption rate throughout, then exposure precision is improved, but exposure efficiency decreases and top shape formation is affected
Solution Approach 1:
Different regions of the photoresist layer are assigned different light absorption rates tailored to their specific functions. The bottom part near the target layer has high light absorption to ensure precise exposure image formation and sharp pattern definition, while the top part has low light absorption to allow sufficient light transmission and maintain exposure efficiency. This localized optimization resolves the contradiction between precision and productivity.
3Productivity
If the photoresist layer has low light absorption rate throughout, then exposure efficiency is improved, but manufacturing precision and pattern resolution deteriorate
Solution Approach 1:
The photoresist layer implements spatially varying light absorption properties: the top region has low absorption to ensure high exposure efficiency and adequate light penetration, while the bottom region adjacent to the target layer has high absorption to achieve sharp pattern definition and high manufacturing precision. This local differentiation simultaneously satisfies both productivity and precision requirements.
4Ease of manufacture
If a single-layer photoresist structure is used, then the process is simple, but top shape control and pattern quality are compromised
Solution Approach 1:
The photoresist layer is structured with distinct functional regions having different light absorption rates - a top part with lower absorption and a bottom part with higher absorption. This creates a functionally differentiated single layer that maintains manufacturing simplicity while achieving superior pattern quality and top shape control through localized property optimization.
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 enhances lithographic resolution and exposure efficiency, allowing for precise patterning with improved photoresist pattern quality and reduced process complexity.
Implementation Method 1
a light absorption rate of the first part is less than a light absorption rate of the second part
Data Source
AI summary
The present disclosure relates to the technical field of semiconductors, and provides a method of processing a photoresist layer, and a photoresist layer. The method of processing a photoresist layer includes: forming a photoresist layer on a target layer, where the photoresist layer includes a first part away from the target layer and a second part close to the target layer; processing the photoresist layer by using a first process, such that a light absorption rate of the first part is less than a light absorption rate of the second part; performing first exposure processing on the photoresist layer to form an exposure image in the second part; and stripping the first part and performing first development processing on the photoresist layer, to pattern the second part into a photoresist pattern.