Substrate Wet Etching Control for Post-Process Film Uniformity
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Solution Overview
Problem
Existing substrate processing methods fail to maintain uniform film thickness after etching, as the film thickness becomes non-uniform again due to post-processing, despite initial attempts to equalize it based on pre-processing film thickness profiles.
Innovation Solution
A substrate processing apparatus and system that control the wet etching amount at each position on the substrate surface based on the characteristics of the post-processing, using a linked processing system that acquires information from pre-processing and post-processing to adjust the etching process accordingly, ensuring uniform film thickness across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If film thickness is equalized based on pre-processing film thickness profile, then film thickness uniformity is improved during etching, but film thickness becomes non-uniform again after post-processing
Solution Approach 1:
The patent applies preliminary action by acquiring information about post-processing characteristics before performing the etching process. The control unit uses this advance information to pre-calculate the etching amount at each position, ensuring that the film thickness remains uniform even after post-processing. This is achieved by obtaining post-processing film thickness change information and using it to adjust the etching profile in advance.
Solution Approach 2:
The patent implements feedback by using information about post-processing characteristics to adjust the etching process. The control unit receives feedback about how the film thickness will change during post-processing and modifies the etching amount at each position accordingly. This feedback loop ensures that the final film thickness profile remains uniform despite the effects of post-processing.
2Ease of operation
If conventional etching is performed without considering post-processing characteristics, then processing simplicity is maintained, but final film thickness uniformity deteriorates
Solution Approach 1:
The patent introduces an intermediary element - a host computer that acts as a mediator between the post-processing apparatus and the etching apparatus. The host computer acquires post-processing characteristic information and transmits it to the control unit, which then calculates the appropriate etching profile. This intermediary system maintains processing simplicity by automating the complex calculations and coordination, while ensuring final film thickness uniformity through precise control.
3Productivity
If etching amount is uniformly applied across the substrate, then processing time is reduced, but film thickness non-uniformity increases due to post-processing effects
Solution Approach 1:
The patent applies local quality by varying the etching amount at different positions on the substrate based on local requirements. Instead of uniform etching, the control unit calculates and applies position-specific etching amounts that account for local post-processing effects. This is achieved by dividing the substrate into multiple regions and controlling the etching amount independently for each region, ensuring uniform final film thickness while maintaining 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 maintains uniform film thickness by dynamically controlling the etching amount during the wet etching process based on post-processing characteristics, preventing non-uniformity and improving the yield of semiconductor device products.
Implementation Method 1
an etching unit configured to etch a surface of a substrate by discharging a processing liquid to the substrate rotated by the substrate holding unit
Data Source
AI summary
A substrate processing apparatus includes: a substrate holding unit configured to hold and rotate a substrate; an etching unit configured to etch a surface of a substrate by discharging a processing liquid to the substrate rotated by the substrate holding unit; and a control unit configured to control an etching amount by the etching unit. In the substrate processing apparatus, the control unit controls an etching amount at each position on the surface of the substrate based on information upon a characteristic of a surface processing to be performed on the substrate by a post-processing apparatus which is configured to perform a post-processing after a substrate processing by the substrate processing apparatus.