Movable Upper Electrode With Buried Dielectric For Plasma Density Control
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Solution Overview
Problem
In substrate processing apparatuses where one electrode is movable with respect to the other, achieving uniform plasma density distribution across the processing space is challenging, leading to difficulties in performing multiple plasma processes uniformly on a substrate within a single chamber.
Innovation Solution
The solution involves burying a dielectric in at least a portion of the upper electrode, which divides the potential difference between the plasma and the ground into two components, allowing for controlled plasma density distribution by adjusting the gap between the electrodes, thereby enabling uniform plasma processing across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If one electrode is made movable with respect to the other to change process conditions, then process flexibility is improved, but plasma density uniformity deteriorates
Solution Approach 1:
The patent applies local quality by making only a specific portion of the upper electrode movable while keeping other portions fixed. This selective movability allows process condition adjustment in certain regions without disrupting plasma uniformity across the entire processing space, thereby resolving the contradiction between process flexibility and plasma density uniformity.
Solution Approach 2:
The upper electrode is segmented into movable and fixed portions, allowing independent control of different regions. This segmentation enables process condition optimization for specific areas while maintaining overall plasma uniformity, thus achieving both process flexibility and manufacturing precision.
2Ease of operation
If the gap between electrodes is changed to adjust plasma density, then process control is improved, but plasma diffusion increases
Solution Approach 1:
The patent implements local quality by allowing gap adjustment only in specific regions of the processing space rather than uniformly across the entire chamber. This localized gap control enables precise plasma density management without causing excessive plasma diffusion, thus improving process control while minimizing plasma loss.
3Adaptability or versatility
If process conditions are changed by moving electrodes, then one-chamber plural processes are enabled, but chamber opening is avoided
Solution Approach 1:
The patent applies dynamics by incorporating movable portions into the electrode structure, allowing process conditions to be changed dynamically without opening the chamber. This dynamic adjustment capability enables one-chamber plural processes while maintaining a sealed chamber environment, thus achieving process versatility without compromising chamber integrity.
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 allows for the realization of one-chamber plural processes with uniform plasma density distribution, enhancing the etching rate and process efficiency by adjusting the plasma density in the processing space without opening the chamber.
Implementation Method 1
by burying the dielectric in at least a portion of the upper electrode; and changing an interval between the upper electrode and the lower electrode
Implementation Method 2
a processing space between the upper electrode and the lower electrode, and a ground which is electrically connected to the upper electrode, one of the upper electrode and the lower electrode being moveable with respect to the other
Data Source
AI summary
A substrate processing apparatus includes a chamber accommodating a wafer, a susceptor disposed inside the chamber and on which the wafer is held, an upper electrode facing the susceptor, and a second high frequency power source connected to the susceptor, wherein the upper electrode is electrically connected to a ground and is moveable with respect to the susceptor. The substrate processing apparatus divides a potential difference between plasma generated in a processing space and the ground into a potential difference between the plasma and a dielectric and a potential difference between the dielectric and the ground by burying the dielectric in the upper electrode, and changes a gap between the upper electrode and the susceptor. Accordingly, plasma density between the upper electrode and the susceptor is changed.