Adjustable Tuning Ring for Edge Uniformity Control
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Solution Overview
Problem
In substrate processing, edge critical dimension uniformity is challenging due to electric field termination effects, leading to non-uniform deposition and etching rates across the substrate, particularly at the perimeter, which affects die yields in semiconductor technology.
Innovation Solution
A process kit for a substrate processing apparatus comprising an edge ring with movable ring components, an adjustable tuning ring, and an actuating mechanism, which adjusts the gap between ring components to control capacitive coupling and ion direction at the substrate edge, thereby improving uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional process kits are used without adjustable components, then the device structure is simple, but edge critical dimension uniformity deteriorates due to electric field termination effects
Solution Approach 1:
The patent implements an adjustable tuning ring that can be dynamically repositioned along the substrate radius, allowing the process kit to adapt its configuration based on the specific edge effect characteristics of different substrates. This dynamic adjustability enables optimization of edge critical dimension uniformity while maintaining a relatively simple base structure.
Solution Approach 2:
The patent changes the positional parameter of the tuning ring relative to the substrate edge to control plasma sheath bending and ion acceleration characteristics. By adjusting the radial position of the tuning ring, the system modifies the electric field distribution and plasma flow patterns, thereby improving edge uniformity without fundamentally changing the device structure.
2Manufacturing precision
If fixed ring components are used, then the device is easy to manufacture, but process uniformity across the substrate deteriorates
Solution Approach 1:
The process kit is segmented into multiple independent components: a base ring structure, an adjustable tuning ring, and an actuating mechanism. This segmentation allows each component to be manufactured separately using standard processes, then assembled together. The modular design maintains ease of manufacture while enabling the complex function of adjustable edge control.
Solution Approach 2:
The patent introduces an intermediary actuating mechanism (such as a motor or actuator) that mediates between the control system and the tuning ring position. This intermediary component simplifies the overall assembly by providing a standardized interface for adjustment, making the system easier to manufacture and maintain while achieving precise process uniformity.
3Manufacturing precision
If the plasma sheath is allowed to bend freely at the substrate edge, then ion acceleration is high, but edge effects cause non-uniform deposition and etching
Solution Approach 1:
The tuning ring is positioned to preemptively counteract the natural bending of the plasma sheath at the substrate edge. By placing the conductive tuning ring at a specific radial position, it creates an opposing electric field that prevents excessive plasma sheath bending and ion acceleration, thereby reducing edge effects before they can cause non-uniform deposition or etching.
Solution Approach 2:
The patent modifies the electric field distribution parameter by introducing the adjustable tuning ring with controlled potential. By changing the radial position and electrical potential of the tuning ring, the system adjusts the plasma sheath curvature and ion acceleration characteristics, transforming the harmful edge effects into controlled conditions that achieve uniform processing.
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 solution enhances edge critical dimension uniformity by controlling the plasma sheath and ion direction, leading to improved die yields and process uniformity across the substrate.
Implementation Method 1
adjusting a height of the second ring component of the edge ring by actuating the adjustable tuning ring interfaced with the component to change a direction of ions at an edge of the substrate
Implementation Method 2
A plasma sheath can bend at the substrate edge depending on the edge ring geometry and therefore ions are accelerated perpendicularly to the plasma sheath
Implementation Method 3
silicon substrates are etched while electrostatically clamped to an electrostatic chuck
Data Source
AI summary
Process kits, processing chambers, and methods for processing a substrate are provided. The process kit includes an edge ring, a sliding ring, an adjustable tuning ring, and an actuating mechanism. The edge ring has a first ring component interfaced with a second ring component that is movable relative to the first ring component forming a gap therebetween. The sliding ring is positioned beneath the second ring component of the edge ring. The adjustable tuning ring is positioned beneath the sliding ring. The actuating mechanism is interfaced with the lower surface of the adjustable tuning ring and configured to actuate the adjustable tuning ring such that the gap between the first and second ring components is varied. In one or more examples, the sliding ring includes a matrix and a coating, the matrix contains an electrically conductive material and the coating contains an electrically insulting material.