VCSEL Module Current Balancing for Uniform Substrate Heating
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Solution Overview
Problem
Existing substrate heat-treating apparatuses using VCSEL devices face challenges in achieving temperature uniformity and reducing temperature deviations during the heat treatment process of flat substrates.
Innovation Solution
A substrate heat-treating apparatus that individually controls the supply current to each VCSEL device, allowing for uniform output and reducing temperature deviations by using a correlation between supply current and output, set as an equation or lookup table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple VCSEL devices are used to cover a large surface region, then the heating area is increased, but temperature uniformity deteriorates due to individual output variations
Solution Approach 1:
The patent applies local quality by assigning different supply current values to different VCSEL devices based on their individual characteristics and positional requirements. Each VCSEL device receives a customized current value from a lookup table that compensates for manufacturing variations and positional differences, ensuring uniform temperature distribution across the large heating area while maintaining individual device characteristics.
2Temperature
If individual output control is implemented for each VCSEL device, then temperature uniformity is improved, but device complexity increases due to individual current control
Solution Approach 1:
The patent implements preliminary action by pre-calculating and storing optimal supply current values for each VCSEL device in a lookup table during the manufacturing or setup phase. This pre-computed data accounts for individual device characteristics and positional variations, allowing the control system to simply retrieve and apply the appropriate current value during operation, thereby achieving precise individual control without requiring complex real-time calculations or control algorithms.
3Area of stationary object
If VCSEL devices are disposed to cover the entire semiconductor wafer, then heating coverage is improved, but temperature deviation increases due to variations in individual device outputs
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the supply current parameter for each VCSEL device based on its individual characteristics and position. The lookup table contains pre-determined current values that compensate for variations in device output, allowing the system to maintain uniform temperature distribution across the entire wafer surface even when using numerous VCSEL devices with inherent manufacturing variations.
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 uniform heating of the flat substrate, reducing temperature deviations and enhancing temperature uniformity, as demonstrated by the measured temperature distributions.
Implementation Method 1
a beam irradiating module including a plurality of VCSEL devices, and configured to irradiate a laser beam to the flat substrate
Implementation Method 2
The beam irradiating module utilizes divergence of a laser beam emitted from the VCSEL device, and may uniformly heat the semiconductor wafer through overlapping of laser beams emitted from the VCSEL devices adjacent to each other
Implementation Method 3
The beam irradiating module utilizes divergence of a laser beam emitted from the VCSEL device, and may uniformly heat the semiconductor wafer through overlapping of laser beams emitted from the VCSEL devices adjacent to each other
Data Source
AI summary
This present disclosure discloses a substrate heat-treating apparatus including a process chamber in which a flat substrate to be heat-treated is placed and a beam irradiating module having a plurality of VCSEL devices configured to irradiate a laser beam to the flat substrate, and the beam irradiation module is configured such that a supply current is controlled to allow outputs of the VCSEL devices to become the same.