Preclean Chamber Liner and Shield Ring for RF Grounding and Flow Conductance
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Solution Overview
Problem
Existing process chambers face challenges in effectively managing contaminants and etched materials during plasma cleaning processes, particularly due to inadequate flow conductance and flow equalization, leading to deposition of unwanted materials on chamber surfaces.
Innovation Solution
The implementation of a process kit comprising a chamber liner, confinement plate, shield ring, and ground straps that maintain electrical connection and facilitate continuous RF grounding, while allowing for vertical movement of the substrate support to accommodate both high-pressure and low-pressure processes, thereby preventing mechanical rubbing and particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a process kit is used to reduce deposition of contaminants and etched materials, then the cleanliness of chamber surfaces is improved, but the flow conductance and flow equalization may be inadequate for removing displaced materials
Solution Approach 1:
The process kit is divided into multiple functional components: a chamber liner for protection, a confinement plate with slots for flow control, and a shield ring for directing plasma flow. This segmentation allows each component to optimize its specific function while collectively maintaining both cleanliness and flow conductance.
Solution Approach 2:
The confinement plate features slots with specific geometries positioned at particular locations to create localized flow patterns. The shield ring is positioned to specifically direct plasma flow where needed. This local quality optimization ensures adequate flow conductance in critical areas while maintaining overall chamber cleanliness.
2Adaptability or versatility
If the substrate support moves vertically to accommodate both high-pressure and low-pressure processes, then process versatility is improved, but mechanical rubbing and particle generation may occur
Solution Approach 1:
The shield ring acts as an intermediary component between the substrate support and the chamber walls. It provides continuous RF grounding and physically shields moving parts from contact with stationary components, eliminating mechanical rubbing and particle generation while allowing vertical movement for process versatility.
Solution Approach 2:
The patent replaces mechanical grounding connections with electromagnetic RF grounding through the shield ring. This substitution eliminates mechanical friction and particle generation from contact between moving and stationary parts, while maintaining electrical continuity for plasma processing.
3Reliability
If ground straps are used to maintain electrical connection between the shield ring and chamber liner, then continuous RF grounding is achieved, but device complexity increases
Solution Approach 1:
The ground straps integrate multiple functions into a single component: electrical grounding, mechanical support for the shield ring, and structural alignment features. This merging reduces the total number of separate components needed while maintaining continuous RF grounding reliability.
Solution Approach 2:
The ground straps serve multiple purposes simultaneously: providing RF grounding path, supporting the movable shield ring, defining positional relationships between components, and facilitating assembly. This multi-functionality reduces overall device complexity while ensuring reliable electrical connection.
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 configuration enables efficient removal of contaminants and etched materials, maintains continuous RF grounding, and allows for rapid switching between high-pressure and low-pressure processes, reducing particle generation and enhancing the cleanliness of the chamber surfaces.
Implementation Method 1
Electromagnetic energy (e.g., radio frequency) is applied to an injected gas, such as argon, to excite the injected gas into a plasma state. The plasma releases ions that bombard the surface of the substrate to remove contaminants and/or material from the substrate.
Implementation Method 2
Preclean chambers, typically, use ion bombardment (induced by RF plasma) to remove the native oxide on the metal contact pads and other materials.
Implementation Method 3
a plurality of ground straps coupled to the shield ring at a first end of each ground strap of the plurality of ground straps and to the confinement plate at a second end of each ground strap to maintain electrical connection between the shield ring and the chamber liner when the shield ring moves
Data Source
AI summary
Embodiments of process kits for use in a process chamber are provided herein. In some embodiments, a process kit for use in a process chamber includes: a chamber liner having a tubular body with an upper portion and a lower portion; a confinement plate coupled to the lower portion of the chamber liner and extending radially inward from the chamber liner, wherein the confinement plate includes a plurality of slots; a shield ring disposed within the chamber liner and movable between the upper portion of the chamber liner and the lower portion of the chamber liner; and a plurality of ground straps coupled to the shield ring at a first end of each ground strap of the plurality of ground straps and to the confinement plate at a second end of each ground strap to maintain electrical connection between the shield ring and the chamber liner when the shield ring moves.