Substrate Batch Inversion for Uniform Phosphoric Acid Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing systems face challenges in reducing processing variations between the upper and lower halves of substrates when immersed in a phosphoric acid solution in a vertical attitude, due to differences in solution freshness at varying depths.
Innovation Solution
A substrate processing system that includes a batch processing apparatus with a first and second attitude changing mechanism, a lifter, and a controller, which performs first and second batch processing by immersing substrates in a chemical liquid, and rotates the substrates to vertically invert them between processing stages, thereby reducing processing variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If substrates are immersed in phosphoric acid solution in vertical attitude for batch processing, then processing efficiency is improved, but processing uniformity deteriorates due to solution freshness variation at different depths
Solution Approach 1:
The patent applies inversion by rotating the substrate carrier 180 degrees around the vertical axis between first and second batch processing. This causes the upper half of substrates (which received fresher solution during first processing) to be positioned at the lower half during second processing, and vice versa. This reciprocal positioning equalizes the etching exposure between upper and lower halves across the two processing cycles, resolving the uniformity issue while maintaining batch processing efficiency.
Solution Approach 2:
The patent implements periodic action by performing two sequential batch processing cycles with intermediate carrier rotation. The first batch processing exposes substrates to phosphoric acid solution, then the carrier is rotated 180 degrees, and the second batch processing repeats the exposure. This periodic repetition with positional inversion ensures that each substrate region receives equivalent cumulative etching exposure, achieving uniformity while maintaining high productivity through batch processing.
2Productivity
If substrates are processed collectively in batch, then productivity is improved, but processing variation between upper and lower halves increases
Solution Approach 1:
The patent uses inversion of the substrate carrier position between two batch processing cycles. By rotating the carrier 180 degrees around the vertical axis, substrates that were in the upper position during first batch processing move to the lower position during second batch processing, and vice versa. This inversion compensates for the depth-related solution freshness variations, ensuring consistent processing results across all substrates while maintaining collective batch processing throughput.
Solution Approach 2:
The patent changes the spatial parameter of substrate positioning by rotating the carrier 180 degrees between processing cycles. This parameter change transforms the original vertical position distribution of substrates, causing upper substrates to become lower substrates and vice versa. This parameter transformation equalizes the cumulative exposure to phosphoric acid solution across all substrate regions, improving processing consistency while maintaining batch processing efficiency.
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 system effectively reduces processing variations between the upper and lower halves of substrates by ensuring uniform exposure to the chemical liquid through vertical inversion of the substrates between batch processing stages.
Implementation Method 1
the substrate group is collectively subjected to an etching treatment
Data Source
AI summary
A controller of a substrate processing system controls a lifter to perform first batch processing to immerse a plurality of substrates in a vertical attitude in a chemical liquid in a chemical treatment tank. The controller controls a second attitude changing mechanism to rotate the plurality of substrates subjected to the first batch processing about a horizontal axis, to vertically invert the plurality of substrates in the vertical attitude. The controller controls the lifter to perform second batch processing to immerse the plurality of vertically-inverted substrates in the vertical attitude in the chemical liquid in the chemical treatment tank.