Substrate Processing VUV Intensity Control Through Quartz Window Feedback
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Solution Overview
Problem
The intensity of vacuum ultraviolet (VUV) light in a process chamber is affected by quartz window transmission efficiency and cannot be effectively controlled, leading to defects and increased absorption, which affects the efficiency of UV treatment processes.
Innovation Solution
A substrate processing apparatus with a measurement unit that includes a tube, a fluorescent body, an optical fiber, and a light sensor to convert and measure UV light intensity, allowing for precise control of UV lamp power through a power controller based on measured intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If VUV light is used for substrate treatment, then treatment efficiency is improved and operating temperature is reduced, but light intensity cannot be controlled due to quartz window transmission issues
Solution Approach 1:
The patent implements a feedback control system where a sensor detects the actual VUV light intensity transmitted through the quartz window, and this information is fed back to a controller that adjusts the lamp power accordingly. This closed-loop feedback mechanism enables precise control of light intensity despite variations in window transmission, resolving the contradiction between high productivity and ease of operation.
Solution Approach 2:
The patent replaces manual or mechanical control methods with an automated electronic control system. The sensor-electronics-controller-lamp circuit system automatically regulates light intensity without mechanical intervention, substituting mechanical control with an electronic feedback-based control mechanism that overcomes the transmission control limitation.
2Productivity
If VUV light is applied for extended periods, then processing productivity increases, but quartz window transmission efficiency deteriorates due to defect accumulation
Solution Approach 1:
The sensor continuously monitors the actual light intensity transmitted through the quartz window and provides real-time feedback to the controller. As the window degrades over time, the feedback signal changes, and the controller automatically compensates by adjusting lamp power to maintain consistent transmitted intensity, thereby maintaining productivity while accounting for window reliability degradation.
Solution Approach 2:
The system performs preliminary monitoring and adjustment before significant degradation affects processing quality. By continuously measuring transmitted light intensity and proactively adjusting lamp power, the system prevents defects caused by insufficient illumination while extending the effective service life of the quartz window.
3Manufacturing precision
If quartz window transmission is increased to improve light delivery, then light absorption defects increase, but reducing transmission improves defects while decreasing treatment effectiveness
Solution Approach 1:
The feedback control system detects variations in transmitted light intensity caused by window absorption defects and automatically adjusts lamp power to compensate. This ensures consistent treatment quality at the substrate while preventing harmful absorption effects from accumulating, resolving the contradiction between manufacturing precision and harmful factors.
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
Enables accurate monitoring and adjustment of VUV light intensity within the processing chamber, maintaining consistent treatment quality and reducing defects in the quartz window.
Implementation Method 1
a fluorescent body disposed at one end of the tube and configured to convert a UV light into a visible light
Data Source
AI summary
A substrate processing apparatus may be presented. The apparatus comprising a lamp unit configured to emit a UV (ultraviolet) light, a lamp compartment configured to contain one or more lamp units, a processing chamber with a susceptor and configured to process a substrate, the susceptor is configured to support a substrate for processing, a separation window disposed between the lamp compartment and the processing chamber, and configured to be transparent for a light from the UV lamp to reach to the substrate, a measurement unit disposed in a wall of the processing chamber, the measurement unit configured to measure a light intensity in the processing chamber, and a power controller electrically connected to the measurement unit and configured to adjust a supply of power to the lamp compartment according to the light intensity measured by the measurement unit.