VUV Transmission Filter for Uniform Plasma Light Processing
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Solution Overview
Problem
Conventional VUV light processing apparatuses face challenges in maintaining uniformity and reproducibility due to variations in light intensity and wafer in-plane uniformity, leading to issues with resist LWR and CD differences between coarse and fine patterns, which affect semiconductor device quality.
Innovation Solution
A sample processing apparatus using a plasma light source with a VUV transmission filter that blocks ions, electrons, and radicals, allowing for uniform application of VUV light across the wafer surface, improving transmittance and reducing roughness on photoresist surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional excimer lamps are used for VUV light processing, then vacuum ultraviolet light can be applied to the wafer, but variations in light intensity and wafer in-plane uniformity occur, leading to resist LWR and CD differences
Solution Approach 1:
A VUV transmission filter is introduced as an intermediary component between the plasma light source and the wafer. This filter selectively transmits VUV light while blocking ions, electrons, and radicals, thereby mediating the interaction to achieve uniform light intensity distribution and eliminate the harmful effects that caused resist LWR and CD variations
Solution Approach 2:
The invention changes the physical state and composition of the light source system by using a plasma light source with controlled gas pressure and composition. By adjusting the plasma generation parameters and introducing a VUV transmission filter, the light intensity distribution and spectral characteristics are optimized to achieve uniform illumination across the wafer surface
2Reliability
If plasma light source with VUV transmission filter is used, then uniformity and reproducibility of VUV light processing is improved, but device complexity increases
Solution Approach 1:
The VUV transmission filter serves multiple functions simultaneously: it transmits VUV light to the wafer, blocks ions and electrons from damaging the photoresist, filters radicals that could cause unwanted chemical reactions, and provides a stable spectral distribution. This multi-functionality improves reliability without requiring separate components for each function, thereby limiting the increase in device complexity
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
The apparatus achieves excellent reproducibility and uniformity in VUV light processing, reducing resist LWR and CD differences, thereby enhancing the accuracy and quality of semiconductor processing.
Implementation Method 1
a plasma light source that emits VUV light including a wavelength of 200 nm or less, the plasma light source including a plasma generating unit that generates plasma in a plasma generating space in the chamber
Implementation Method 2
a VUV transmission filter provided between the plasma light source and a sample to be processed, the VUV transmission filter transmits VUV light including the wavelength of 200 nm or less and does not transmit electrons, ions, and radicals in the plasma
Data Source
AI summary
There is provided a VUV light processing apparatus that can apply vacuum ultraviolet light to the entire surface of a wafer in excellent reproducibility and can process the wafer with VUV (vacuum ultraviolet) light in excellent reproducibility. A VUV light processing apparatus includes: a chamber connected with a gas supply apparatus and an evacuation apparatus, the chamber being capable of reducing the pressure inside the chamber; a plasma light source that generates VUV light including a wavelength of 200 nm or less, the plasma light source including a plasma generating unit that generates plasma in the chamber; and a VUV transmission filter provided between a stage on which a sample to be processed is placed and the sample in the chamber, the VUV transmission filter transmitting the VUV light including a wavelength of 200 nm or less and not transmitting electrons, ions, and radicals in plasma, the VUV transmission filter having the outer diameter size larger than that of the sample.