Substrate Etching Scan Velocity Control for Uniformity
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Solution Overview
Problem
Existing substrate processing methods face challenges in achieving uniform etching across the substrate surface due to differences in etching amounts between the edge and center portions, which are not adequately addressed by existing methods that adjust scan velocity according to single equations or continuous changes, leading to low uniformity and complex control requirements.
Innovation Solution
A substrate processing method that determines a moving velocity for the liquid application position from the edge to the center of the substrate based on etching liquid supply conditions, using a scan velocity determining step to adjust for etching liquid density, temperature, supply time, and type, and employing a control device to manage the nozzle movement and etching liquid supply, ensuring uniformity by matching changes in center discharging conditions with corresponding scan step adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If continuous scan velocity change according to single equations is used, then etching uniformity is improved, but control complexity increases
Solution Approach 1:
The scan velocity change is divided into multiple discrete steps rather than continuous adjustment. The control device sets different scan velocities at different time points or positions, creating a stepped velocity profile that approximates the optimal continuous curve while simplifying control implementation.
Solution Approach 2:
The scan velocity is made dynamically adjustable during the scan process. The control device modifies the scan velocity based on real-time position or time parameters, allowing the system to adapt the scanning speed to compensate for etching uniformity variations without requiring complex continuous control algorithms.
2Manufacturing precision
If scan velocity is adjusted to compensate for etching differences, then etching uniformity is improved, but process complexity increases
Solution Approach 1:
The optimal scan velocity profile is pre-calculated and stored in the control device based on the known etching characteristics of the substrate. Before the actual etching process begins, the control device loads the predetermined velocity parameters that will compensate for edge-to-center etching differences, eliminating the need for complex real-time calculations during processing.
Solution Approach 2:
The scan velocity parameter is systematically varied according to a predetermined schedule or position-based profile. By changing the velocity parameter in discrete steps rather than continuously, the system achieves etching uniformity compensation while keeping the control logic relatively simple and the process易于实施.
3Manufacturing precision
If multiple parameters are adjusted simultaneously, then etching uniformity is improved, but control difficulty increases
Solution Approach 1:
The invention extracts and focuses on adjusting only the scan velocity parameter as the primary control variable. By isolating this single parameter for adjustment while keeping other parameters (such as etching liquid flow rate, substrate rotation speed) constant, the control difficulty is significantly reduced while still achieving improved etching uniformity.
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
This method enhances etching uniformity across the substrate surface by determining optimal scan velocities based on etching liquid supply conditions, effectively offsetting etching amount differences between the edge and center portions, even under varying conditions, and simplifies control by using stepwise or constant velocity changes.
Implementation Method 1
the temperature of the etching liquid supplied toward the principal face of the substrate in the center discharge step decreases toward the edge portion of the principal face of the substrate affected by vaporization heat
Data Source
AI summary
Scan step (S3) for moving a nozzle with etching liquid discharged therefrom is carried out such that etching liquid application position toward the rotating substrate moves from the edge portion toward the center portion of the principal face of the substrate. Thereafter, center discharging step (S4) for continuing the supply of the etching liquid toward the principal face of the substrate under the condition that the application position is positioned at the center portion of the principal face of the substrate W is conducted. Moving velocity of the liquid application position in the scan step (S3) is determined in accordance with supply condition of the etching liquid toward the substrate under the condition that the liquid application position is positioned at the center portion of the principal face of the substrate.