Resist Pattern Formation via Segmented Exposure and Base Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional resist pattern formation methods face limitations in improving sensitivity, resolution, and line width roughness performance due to the trade-off relationship between these parameters, and are hindered by defects from random noise such as photon shot noise.
Innovation Solution
A resist pattern formation method involving a resist layer with a base resin, sensitizer precursor, acid generator, and base generator, where pattern exposure and flood exposure are used to generate and neutralize acids and bases, with specific ratios and heat treatment to optimize sensitivity and resolution while reducing line width roughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sensitivity of resist is increased, then exposure time is reduced, but resolution and line width roughness performance decrease
Solution Approach 1:
The patent divides the exposure process into two distinct stages: pattern exposure and flood exposure. Pattern exposure forms the initial latent image with high spatial precision, while flood exposure uniformly generates additional acid throughout the resist layer to enhance sensitivity. This segmentation allows each exposure step to optimize for its specific function without compromising the other performance parameters.
Solution Approach 2:
The patent introduces a base generator that preliminarily prepares basic components in the resist layer before exposure. During pattern exposure, these pre-positioned bases neutralize acids in unexposed regions, sharpening the pattern boundaries. This preliminary preparation enables the subsequent flood exposure to increase sensitivity without degrading resolution, as the pattern definition has already been established.
2Productivity
If sensitivity of resist is increased, then throughput is improved, but line width roughness performance decreases
Solution Approach 1:
By separating the exposure into pattern and flood stages, the patent enables the flood exposure to uniformly increase acid generation across the entire resist layer, enhancing sensitivity and throughput. The pattern exposure stage maintains precise line width control, while the flood exposure adds sensitivity without significantly increasing line width roughness due to the uniform nature of the exposure.
Solution Approach 2:
The base generator preliminarily distributes bases throughout the resist layer before exposure. During development, these bases neutralize acids in a controlled manner, reducing the impact of random fluctuations in acid generation. This preliminary distribution smooths out variations in line width that would otherwise result from photon shot noise, thereby reducing line width roughness while maintaining high sensitivity.
3Productivity
If light source output power is increased, then exposure time is reduced, but system cost increases
Solution Approach 1:
The patent segments the exposure process into pattern exposure and flood exposure, allowing the use of a lower-power light source. The pattern exposure uses the light source to form the critical pattern features, while the flood exposure uniformly illuminates the entire resist layer to generate additional acid for sensitivity enhancement. This segmentation enables reduced light source power requirements compared to a single high-power exposure system.
Solution Approach 2:
The patent introduces a base generator as an intermediary component that amplifies the effect of the light source. The base generator provides pre-positioned bases that react with acids generated during exposure, extending the effective sensitivity of the resist system. This intermediary enables the use of lower-power light sources while maintaining high throughput, as the base generator enhances the chemical amplification process without requiring increased optical power.
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 enhances sensitivity and resolution while minimizing line width roughness and photon shot noise defects, thereby increasing throughput and reducing exposure system costs.
Implementation Method 1
generating an acid from the acid generator by performing pattern exposure on the resist layer; generating an acid from the acid generator by performing flood exposure on the resist layer
Implementation Method 2
performing heat treatment on the resist layer after the flood exposure
Data Source
AI summary
A resist pattern formation method includes: forming on a substrate a resist layer containing a base resin, a sensitizer precursor, an acid generator, a base generator, and a base; generating a sensitizer from the sensitizer precursor; generating an acid from the acid generator and a base from the base generator; performing heat treatment on the resist layer after flood exposure; and developing the resist layer after the heat treatment. A ratio (C1=A1/B1) of a value (A1) representing an acid in pattern exposure to a value (B1) representing a base in the pattern exposure satisfies a relationship 0.9×C1<C2<10×C1 relative to a ratio (C2=A2/B2) of a value (A2) representing an acid in flood exposure to a value (B2) representing a base in the flood exposure.