Illuminating Apparatus Sensor Distance Adjustment for Photolithography
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Solution Overview
Problem
In photolithography processes, miniaturization of patterns leads to increased defect rates and decreased yields due to slight changes in exposure conditions, causing uneven line widths and illuminance unevenness in the illumination region.
Innovation Solution
An illuminating apparatus is designed with a light emitting portion, a mounting table, a sensor to detect light emitted and reflected, an adjusting unit to set the distance between the object and sensor, and a controlling unit to adjust the light amount based on sensor detection, ensuring uniform illuminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a sensor is disposed in the vicinity of a light emitting portion to detect diffused light or diffusely reflected light, then the integrated exposure light amount can be controlled to reduce illuminance unevenness, but the influence of diffused light from other than the light emitting portion to be controlled cannot be ignored
Solution Approach 1:
A reflecting member is introduced as an intermediary between the light emitting portion and the sensor. This reflecting member reflects light from the light emitting portion toward the sensor, enabling accurate detection of the light amount from the specific light emitting portion while blocking diffused light from other portions. The sensor thus receives primarily the reflected light from the target light emitting portion, improving measurement precision without sacrificing the ability to control illuminance uniformity.
Solution Approach 2:
The invention extracts and isolates the light signal from the specific light emitting portion by using the reflecting member to direct only that portion's light to the sensor. This extraction method separates the desired signal (light from the controlled light emitting portion) from unwanted signals (diffused light from other portions), thereby improving the accuracy of light amount detection for controlling illuminance uniformity.
2Illumination intensity
If the amount of diffused light is monitored to control illuminance unevenness, then some uniformity can be achieved, but the control accuracy is insufficient due to interference from other light sources
Solution Approach 1:
The reflecting member serves as a reliable intermediary that establishes a direct optical path from the light emitting portion to the sensor. This mediated connection ensures that the sensor accurately measures the light amount from the intended light emitting portion, providing reliable feedback for controlling the illumination intensity uniformity across the illumination region.
Solution Approach 2:
The system uses the sensor to detect the light amount from the light emitting portion via the reflecting member, and this detection result is fed back to control the light emitting portion's output. This feedback mechanism reliably adjusts the illumination intensity to maintain uniformity, with the reflecting member ensuring that the feedback signal accurately represents the controlled light source.
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 effectively reduces illuminance unevenness, improving the accuracy and yield of pattern transfer in photolithography processes by ensuring uniform integrated exposure light amounts across the illumination region.
Implementation Method 1
a sensor configured to detect an amount of light emitted from the light emitting portion and reflected by the object
Data Source
AI summary
An illuminating apparatus, including: a light emitting portion; a mounting table on which an object irradiated with a light from the light emitting portion is mounted; a sensor configured to detect an amount of light emitted from the light emitting portion and reflected by the object; an adjusting unit configured to adjust a distance between the object and the sensor; and a controlling unit configured to control a light amount of the light emitting portion based on a detection result of the sensor in a state in which a distance between the object and the sensor is adjusted by the adjusting unit.