Conductive Edge Member Bias for Plasma Ion Density Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma processing technologies face challenges in uniformly adjusting the plasma ion density near the substrate edge, which affects the efficiency of plasma processing such as etching.
Innovation Solution
A plasma processing method and apparatus that apply a positive voltage to a conductive member closer to the grounded chamber wall than the substrate, adjusting the plasma ion density by controlling the potential of the conductive member relative to the substrate, using radio frequency or pulsed bias power to optimize ion distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dome-shaped upper electrode is used to make plasma density uniform, then plasma density uniformity is improved, but the ability to independently adjust ion density near the substrate edge is limited
Solution Approach 1:
The invention divides the electrode structure into multiple independent conductive members (edge ring and upper electrode) that can be controlled separately. The edge ring is electrically isolated from the upper electrode, allowing independent voltage application to each component. This segmentation enables separate control of plasma density in different regions, particularly allowing independent adjustment of ion density near the substrate edge while maintaining overall plasma uniformity.
Solution Approach 2:
The invention applies different voltages to different spatial regions of the plasma chamber. By applying a voltage different from the substrate potential to the edge ring (conductive member), it creates a localized electric field that specifically affects the plasma ion density near the substrate edge. This local quality control allows precise adjustment of ion density in the edge region without disrupting the overall plasma uniformity achieved by the dome-shaped upper electrode.
2Manufacturing precision
If the conductive member is positioned closer to the substrate, then ion density control near the substrate edge is improved, but the risk of interfering with substrate processing is increased
Solution Approach 1:
The edge ring serves as an intermediary component between the upper electrode and the substrate. It is positioned closer to the substrate than the upper electrode but maintains a controlled distance. The edge ring mediates the electric field distribution, creating a localized effect on ion density near the substrate edge while preventing direct interference with the substrate processing. The electrical isolation and controlled positioning of this intermediary element allow precise ion density control without harmful side effects.
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 effectively increases the density of negative ions near the substrate edge, allowing for precise adjustment of positive ion density and enhancing the efficiency of plasma processing operations like etching.
Implementation Method 1
plasma is being generated in the chamber for plasma processing on the substrate
Implementation Method 2
applying a positive voltage to a conductive member when plasma is being generated in the chamber
Data Source
AI summary
A plasma processing method according to an exemplary embodiment includes preparing a substrate in a chamber of a plasma processing apparatus. The substrate is disposed on a substrate support in the chamber. The substrate support includes a lower electrode and an electrostatic chuck. The electrostatic chuck is provided on the lower electrode. The plasma processing method further includes applying a positive voltage to a conductive member when plasma is being generated in the chamber for plasma processing on the substrate. The conductive member extends closer to a grounded side wall of the chamber than the substrate.