Rotating Substrate Holder for Critical Dimension Profile Control
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Solution Overview
Problem
Semiconductor fabrication processes face challenges in achieving uniform profile control of critical dimensions during etching, particularly due to uneven reaction environments and substrate profiles, leading to non-uniform post-process critical dimensions.
Innovation Solution
An etching apparatus with a substrate holder that can be rotated and tilted, controlled by a process control system to adjust parameters such as temperature, gas flow, and rotational speed, to compensate for uneven environments and profiles, ensuring uniform etching across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used without substrate rotation or tilting, then the process is simple and easy to operate, but the post-process critical dimension uniformity is poor due to uneven reaction environments
Solution Approach 1:
The substrate holder is made rotatable and tiltable during the etching process, transforming a static holding mechanism into a dynamic one. This allows real-time adjustment of substrate orientation and rotation speed to compensate for uneven reaction environments, thereby improving critical dimension uniformity without requiring multiple separate processing steps
Solution Approach 2:
The system changes physical parameters including rotation speed, tilt angle, and temperature distribution across the substrate surface. By dynamically adjusting these parameters during etching, the process compensates for non-uniform reaction conditions and achieves better dimensional control
2Manufacturing precision
If substrate rotation is implemented to improve uniformity, then the critical dimension uniformity improves, but the process time and energy consumption increase
Solution Approach 1:
Instead of rotating the substrate at maximum speed throughout the entire etching process, the system applies partial rotation only during specific phases or at optimized speeds. This reduces unnecessary energy consumption and process time while still achieving the uniformity benefits where needed
3Manufacturing precision
If multiple process adjustments are made based on pre-process substrate data, then the profile control precision improves, but the measurement and control complexity increases
Solution Approach 1:
The system measures pre-process substrate data (such as critical dimension variations across the substrate surface) and uses this information to feedback-adjust etching parameters including rotation speed, tilt angle, and temperature distribution. This closed-loop control enables precise profile control while automating the complexity of multiple parameter adjustments
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 approach significantly improves the uniformity of post-process critical dimensions by up to 51%, achieving desired profiles such as zigzag or stair shapes, and provides feedback for optimizing subsequent processes.
Implementation Method 1
FIG. 7 is a schematic diagram illustrating a centrifugal effect resulting from rotation of a substrate holder of the system in accordance with some embodiments.
Implementation Method 2
FIG. 9 is a schematic diagram illustrating that the substrate holder is tilted in accordance with some embodiments.
Implementation Method 3
A recipe adjustment calculation is performed for the substrate to generate recipe adjustment data. Process parameters of the etching process for the substrate are determined based on the substrate process recipe and the recipe adjustment data, and the etching process is performed on the substrate according to the process parameters
Data Source
AI summary
An etching apparatus is provided to be able to rotate or tilt a substrate holder on which a to-be-processed substrate is placed. According to a profile of a pre-process critical dimension of the substrate, the etching apparatus may rotate or tilt the substrate holder during an etching process in order to achieve a desired profile of a post-process critical dimension of the substrate that is related to the pre-process critical dimension.