Non-Movable Edge Ring Tuning for Plasma Sheath Uniformity
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Solution Overview
Problem
Existing substrate processing methods suffer from non-uniform plasma edge effects, leading to significant process non-uniformities at the substrate perimeter, which can cause particle generation and contamination, and current solutions like movable deposition rings introduce additional contamination risks.
Innovation Solution
A substrate processing apparatus featuring a non-movable edge ring and a sliding ring that is capacitively or electromechanically coupled to conductive pins or a baseplate, allowing adjustment of capacitive coupling to control the plasma sheath without physically moving the edge ring, thereby tuning the plasma edge profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a movable deposition ring is used to control plasma sheath, then edge effects are compensated, but particle generation and contamination occur
Solution Approach 1:
The system divides the deposition ring into two separate components: a stationary edge ring that remains fixed during processing, and a movable sliding ring that can be positioned beneath the substrate. This segmentation allows the edge ring to maintain plasma sheath control without the contamination issues of movable rings, while the sliding ring provides the necessary adjustability through capacitive coupling changes.
Solution Approach 2:
The sliding ring acts as an intermediary component that indirectly influences the plasma sheath at the substrate edge. By adjusting the position of the sliding ring beneath the substrate, the system modifies capacitive coupling to control the electric field and plasma sheath shape without requiring the edge ring itself to move, thereby avoiding particle generation from movable edge components.
2Manufacturing precision
If edge ring is physically moved to influence plasma sheath, then ion focusing is achieved, but contamination is introduced
Solution Approach 1:
The system replaces the mechanical movement of the edge ring with an electromagnetic field-based control mechanism. The sliding ring's position adjustments modify capacitive coupling, which in turn controls the electric field distribution and plasma sheath shape through field effects rather than direct mechanical movement of the edge ring, eliminating contamination from movable edge components.
3Manufacturing precision
If deposition ring is raised to bend plasma sheath, then edge uniformity is improved, but device complexity increases
Solution Approach 1:
Instead of raising the edge ring to bend the plasma sheath, the system inverts the approach by positioning the sliding ring beneath the substrate. The sliding ring's vertical displacement adjusts capacitive coupling to control the electric field and plasma sheath from below, achieving edge uniformity improvement while keeping the edge ring stationary and simplifying the overall mechanism.
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 enhances etch rate uniformity across the substrate surface, improving wafer processing yield by precisely controlling the plasma sheath without introducing additional contamination.
Implementation Method 1
displacing a sliding ring along a direction that changes an amount of capacitive coupling between the edge ring and a cathode of a power source
Implementation Method 2
forming a plasma above the substrate, and tuning a voltage on the edge ring by displacing a sliding ring along a direction that changes an amount of capacitive coupling between the edge ring and a cathode of a power source to control a plasma sheath near an edge of the substrate
Data Source
AI summary
Embodiments described herein generally related to a substrate processing apparatus. In one embodiment, a process kit for a substrate processing chamber disclosed herein. The process kit includes an edge ring configured to circumscribe a substrate in the semiconductor processing chamber, at least one conductive pin electrically coupled to the edge ring, a sliding ring positioned beneath the edge ring and comprising at least one insert hole for receiving the at least one conductive, and an actuator operable to displace the sliding ring relative to the at least one conductive pin along a direction that changes an amount of capacitive coupling between the at least one conductive pin and the sliding ring.