Substrate Processing Control for Film Thickness Drift
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Solution Overview
Problem
Existing substrate processing technologies face challenges in maintaining consistent film thickness and quality due to factors like cleaning, pre-coat, and waiting times, which result in short-term and long-term variations in processing results.
Innovation Solution
A substrate processing apparatus and method that utilize a controller to modify control parameters with first and second modification values that vary over time, suppressing both short-term and long-term film thickness variations by adjusting parameters such as cycle frequency and processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single modification value is used to adjust control parameters, then the system can respond to either short-term or long-term variations, but it cannot simultaneously suppress both short-term and long-term film thickness variations
Solution Approach 1:
The modification value is divided into two distinct components: a first modification value for short-term variations (addressing cleaning and pre-coat effects) and a second modification value for long-term variations (addressing waiting time effects). This segmentation allows each component to target specific time scales independently, enabling simultaneous suppression of both short-term and long-term film thickness variations without requiring an overly complex unified system.
2Manufacturing precision
If the control parameter is adjusted frequently to maintain film thickness, then short-term variations are suppressed, but the system becomes sensitive to cleaning and pre-coat effects
Solution Approach 1:
The first modification value is applied in advance to compensate for the known effects of cleaning and pre-coat operations. By anticipating these disruptions and pre-adjusting the control parameter, the system maintains film thickness consistency without becoming overly sensitive or unstable after cleaning events occur.
3Manufacturing precision
If the recipe is modified based on measurement information, then film thickness can be maintained, but waiting time in chamber affects the processing result
Solution Approach 1:
The control parameter modification system dynamically adapts to different time scales of variation. The second modification value specifically addresses long-term drift caused by waiting time in the chamber, allowing the system to maintain film thickness consistency even during extended processing intervals without requiring frequent recipe modifications that would amplify waiting time effects.
Data Source
AI summary
Examples of a substrate processing apparatus includes a device for subjecting a substrate to processing, and a controller for modifying a control parameter predetermined to control the device with a first modification value and a second modification value that vary over time, thereby calculating a modified parameter, and controlling the device based on the modified parameter, wherein the first modification value has a shorter term for modifying the control parameter than the second modification value.