Exposure Device Illuminance Measurement for VUV Substrate Processing
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Solution Overview
Problem
Existing exposure devices struggle to accurately adjust the exposure amount of vacuum ultraviolet rays on substrates due to changes in illuminance, leading to inconsistent exposure processing.
Innovation Solution
An exposure device equipped with a light source, an illuminometer to measure illuminance, and a controller that calculates and adjusts the exposure amount based on real-time measurements, ensuring the illuminometer's light receiving surface is at a constant height relative to the substrate, allowing for accurate exposure amount calculation and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If illuminance is measured before exposure processing, then exposure amount can be calculated in advance, but illuminance changes during exposure cause inaccurate exposure adjustment
Solution Approach 1:
The patent implements real-time feedback by measuring illuminance during the exposure process itself rather than before. The illuminometer continuously monitors the actual illuminance reaching the substrate, and this measured value is fed back to the control unit, which adjusts the exposure time accordingly to maintain accurate exposure amounts despite illuminance variations.
Solution Approach 2:
The patent establishes a predetermined relationship between illuminance and exposure time before exposure begins. The control unit stores multiple sets of illuminance values and corresponding exposure times, allowing it to quickly determine the appropriate exposure time based on the currently measured illuminance without complex real-time calculations during exposure.
2Manufacturing precision
If light source moves closer to substrate for better exposure, then exposure uniformity improves, but risk of light source contamination increases
Solution Approach 1:
The patent introduces a light blocking member as an intermediary between the light source and substrate. This member can be positioned to block direct line-of-sight paths that would allow debris or contaminants to travel from the substrate back to the light source, while still allowing the light source to be positioned close enough to the substrate to achieve uniform exposure.
Solution Approach 2:
The patent positions the illuminometer in a specific spatial dimension - laterally offset from the direct light path but still within the illumination field. This allows the illuminometer to measure illuminance accurately without being in the direct path where contamination would occur, separating the measurement function from the potentially contaminated exposure zone.
3Productivity
If substrate moves during exposure for high throughput, then productivity increases, but exposure amount control becomes difficult
Solution Approach 1:
The patent uses real-time illuminance measurement during exposure to provide feedback on the actual exposure conditions. Even when the substrate moves during exposure, the control unit continuously monitors illuminance and adjusts the exposure time based on the measured values, ensuring accurate exposure amounts are achieved regardless of substrate motion or throughput speed.
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 configuration enables precise control over the exposure amount, ensuring accurate and consistent exposure processing even with changes in illuminance, thereby improving the accuracy and efficiency of substrate exposure.
Implementation Method 1
an illuminometer that receives part of the vacuum ultraviolet rays and measures illuminance of the received vacuum ultraviolet rays during an emission period
Data Source
AI summary
Vacuum ultraviolet rays are emitted to a surface to be processed of a substrate to be processed by a light source. During an emission period in which the vacuum ultraviolet rays are emitted from the light source to the substrate, part of the vacuum ultraviolet rays is received by an illuminometer, and illuminance of the received vacuum ultraviolet rays is measured. A light receiving surface of the illuminometer is located at a constant height that is based on the surface to be processed of the substrate during the emission period of the vacuum ultraviolet rays. An exposure amount of the substrate is calculated based on the illuminance measured by the illuminometer. Emission of the vacuum ultraviolet rays from the light source to the substrate is stopped based on the calculated exposure amount of the substrate.