Etching Apparatus Dynamic Control for Bevel Precision
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Solution Overview
Problem
Existing bevel etching technologies face challenges in precisely controlling the etching process for semiconductor wafers, particularly in managing the deviation and diffusion of etching solutions, which can lead to uneven film removal and re-adherence issues.
Innovation Solution
An etching apparatus with a substrate holder, rotation driver, liquid discharge unit, and controller that adjusts rotational velocity, discharge velocity, and discharge direction of the etching solution to maintain immediate deviation conditions, ensuring precise control over the etching process and preventing solution re-adherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the etching solution is discharged to the peripheral portion of the substrate, then the etching process can be performed, but the etching solution may deviate from the substrate immediately after landing, causing unintended etching or re-adherence issues
Solution Approach 1:
The system dynamically adjusts the rotational velocity of the substrate holder and the discharge velocity/direction of the liquid discharge unit based on real-time detection of etching solution behavior. This dynamic control allows the system to maintain optimal conditions for immediate deviation while preventing re-adherence, resolving the contradiction between achieving precise etching and avoiding harmful solution behavior.
Solution Approach 2:
The controller modifies operational parameters including rotational velocity, discharge velocity, and discharge direction of the etching solution to establish and maintain immediate deviation conditions. By changing these parameters, the system ensures the etching solution deviates immediately after landing, preventing re-adherence while maintaining etching precision.
2Manufacturing precision
If the rotational velocity of the substrate is increased to control etching uniformity, then etching uniformity improves, but control complexity increases
Solution Approach 1:
The system incorporates a detector that monitors the state of the etching solution and provides feedback to the controller. The controller uses this feedback to automatically adjust rotational velocity and discharge parameters, maintaining etching uniformity without requiring complex manual control. This feedback mechanism simplifies the overall control complexity while achieving precise etching uniformity.
3Reliability
If the discharge velocity of the etching solution is increased to prevent re-adherence, then re-adherence is prevented, but etching precision may be compromised
Solution Approach 1:
The system changes multiple parameters simultaneously - not only discharge velocity but also rotational velocity and discharge direction - to achieve immediate deviation conditions. This multi-parameter adjustment prevents re-adherence while maintaining etching precision by optimizing the interaction between the etching solution and substrate surface.
Solution Approach 2:
The system dynamically balances discharge velocity with rotational velocity to prevent re-adherence while maintaining etching precision. The controller adjusts these parameters in real-time based on detected conditions, ensuring that high discharge velocity does not compromise etching precision but rather works in conjunction with other parameters to achieve both reliability and precision.
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 apparatus enables precise control over the etching process, allowing for selective etching of intended areas with high precision and preventing unintended etching, thereby optimizing film removal and maintaining process accuracy.
Implementation Method 1
a vacuum chuck configured to hold a substrate in a horizontal posture and rotates the substrate around a vertical axis
Implementation Method 2
a process of removing any unnecessary film on a peripheral portion of a circular substrate, such as a semiconductor wafer, by wet etching with a chemical liquid
Data Source
AI summary
An etching apparatus includes a substrate holder configured to hold a substrate; a rotation driver configured to rotate the substrate holder around a rotation axis; a liquid discharge unit configured to discharge an etching solution to a peripheral portion of the substrate; and a controller configured to control an operation of the etching apparatus by controlling at least the rotation driver and the liquid discharge unit. The controller controls at least one of a rotational velocity of the substrate, a discharge velocity of the etching solution from the liquid discharge unit or a discharge direction of the etching solution from the liquid discharge unit to etch the substrate under immediate deviation conditions in which the etching solution is deviated from the substrate immediately after the etching solution from the liquid discharge unit lands at a liquid landing point in the peripheral portion of the substrate.