Excimer Lamp UV Sensing Layout for Stable Feedback Control
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Solution Overview
Problem
Existing ultraviolet light emission devices for semiconductor and liquid crystal substrates face challenges in stabilizing wavelength characteristics due to temperature variations, leading to deteriorated feedback control performance, as the light emitted for workpiece processing differs from the light detected for feedback control.
Innovation Solution
An ultraviolet light emission device configuration featuring an excimer lamp with a light intensity sensor and reflection members to directly detect ultraviolet light emitted towards the object, ensuring the detected light intensity is equal to the intensity applied to the object, and including a reflective film on the light-emitting tube to maintain consistent light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a lighting port is provided in a reflective film and ultraviolet light is detected by an optical monitor, then feedback control can be implemented, but the structure of the lamp must be changed according to the position of the optical monitor, causing the detection portion and workpiece processing portion to differ in structure, which deteriorates feedback control performance
Solution Approach 1:
The patent combines the light detection function and workpiece processing function into a single integrated structure. The optical monitor is positioned to detect ultraviolet light that has been reflected from the workpiece area, allowing the same light path to serve both detection and processing purposes. This eliminates the need for separate detection and processing portions, thereby improving feedback control performance while avoiding excessive structural complexity.
Solution Approach 2:
The reflective film serves as an intermediary element that redirects ultraviolet light from the workpiece area to the optical monitor. This mediator enables the optical monitor to detect the actual light intensity applied to the workpiece without requiring direct line-of-sight access, thus maintaining structural integration while achieving accurate feedback control.
2Temperature
If the outer wall surface of the light-emitting tube is cooled on the side opposite to the workpiece, then cooling efficiency is improved, but the temperature difference causes wavelength characteristic variations between detected light and emitted light, deteriorating feedback control performance
Solution Approach 1:
The patent applies selective cooling to specific regions of the light-emitting tube. Instead of uniform cooling across the entire tube, the cooling structure is positioned to cool only the region that does not interfere with the light detection path. This local cooling approach maintains cooling efficiency while minimizing temperature-induced wavelength variations in the detection region, thereby preserving feedback control accuracy.
3Stability of the object's composition
If feedback control is implemented by constantly monitoring ultraviolet light intensity and adjusting input power, then wavelength characteristic stability can be improved, but the detected light intensity may not accurately represent the light applied to the workpiece, reducing control accuracy
Solution Approach 1:
The patent implements a feedback control system where the optical monitor continuously measures the intensity of ultraviolet light reflected from the workpiece area. This measured intensity is fed back to the control system, which adjusts the input power to the excimer lamp to maintain consistent light intensity on the workpiece. The reflective film ensures that the detected light accurately represents the light applied to the workpiece, thereby achieving both wavelength stability and measurement accuracy.
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
Enhances the performance of feedback control by ensuring the detected light intensity is consistent with the light applied to the object, improving stability and accuracy in ultraviolet light emission processes.
Implementation Method 1
a first reflection member disposed around the excimer lamp and facing a part of the light emission surface in longitudinal direction, wherein ultraviolet light emitted from the light emission surface is reflected by the first reflection member and enters the light intensity sensor
Implementation Method 2
a reflective film that is formed on an inner wall surface of the light-emitting tube and that faces the light emission surface across a tube axis of the light-emitting tube
Data Source
AI summary
An ultraviolet light emission device includes: an excimer lamp having an elongated shape and having a light emission surface that emits ultraviolet light toward an object for irradiation; a light intensity sensor that is disposed around the excimer lamp and detects ultraviolet light; and a first reflection member disposed around the excimer lamp and facing a part of the light emission surface in a longitudinal direction, wherein ultraviolet light emitted from the light emission surface is reflected by the first reflection member and enters the light intensity sensor.