Electrode Pattern for Resistance Heating Element Wafer Uniformity
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Solution Overview
Problem
Poor uniformity of heating in wafer processing apparatuses due to inadequate design of resistance heating elements leads to uneven heating of wafers, affecting film thickness and etching accuracy in semiconductor production.
Innovation Solution
Optimized electrode pattern design that matches power density with heat loss boundary conditions, reduces electrode width near heat loss areas, and adjusts path widths to compensate for heat loss at contact areas and holes, ensuring uniform temperature distribution across the wafer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the electrode width is reduced near heat loss areas (contacts and holes), then the power density increases to compensate for heat loss, but the electrode structure becomes more complex with variable width adjustments
Solution Approach 1:
The electrode pattern implements local quality by varying the width of electrode paths in different regions. Specifically, the width is reduced near heat loss areas (contacts and holes) to increase power density locally, while maintaining standard width in other areas. This localized modification addresses the temperature uniformity problem without making the entire electrode structure complex.
2Power
If the electrode paths are adjusted to circle around contacts or reduce width at connections, then heat generation is improved in contact areas, but the manufacturing precision requirements increase
Solution Approach 1:
The invention applies parameter changes by systematically varying the electrode path width as a design parameter. The width is adjusted to specific ratios (0.5-0.95 of original width) near heat loss areas to optimize power density. This controlled parameter modification achieves the desired power distribution while maintaining manufacturability through clear design rules.
3Temperature
If the outermost electrode path width is reduced to insulate main heater area from tab heat loss, then temperature uniformity improves, but the electrode area decreases
Solution Approach 1:
The outermost electrode path implements local quality by having reduced width specifically at regions adjacent to tabs where heat loss occurs. This localized width reduction creates thermal insulation effect at the boundaries while preserving the full electrode area in the main heating region, thus achieving temperature uniformity without significant area loss.
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
Achieves uniform temperature distribution with minimal localized non-uniformity, enhancing the heating efficiency and reducing stress concentration, thereby improving the accuracy and yield of semiconductor production processes.
Implementation Method 1
Ceramic heaters containing heating elements have been used to support the wafers and substrates and to heat them to a specified treating temperature
Data Source
AI summary
There is disclosed a wafer processing apparatus having optimized electrode patterns for its resistive heating element. The optimized electrode pattern is designed to compensate for the heat loss around contact areas, electrical connections, and through-holes, etc., by generating more heat near or around those areas, providing maximum temperature uniformity. In another embodiment of the optimized design of the invention, the resistance of heating element closely matches the impedance of the power supply for higher efficiency, especially when higher operating temperature or higher electrical power is required.