In Situ Plasma Cleaning via Deposition Ring Grounding
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Solution Overview
Problem
Current plasma cleaning processes in Physical Vapor Deposition (PVD) chambers face challenges as they often require venting the chamber to remove metallic deposits, leading to increased downtime due to the risk of resputtering metallic material, which can damage components and reduce chamber uptime.
Innovation Solution
A method and apparatus for plasma cleaning that allows for grounding a metal film on chamber components without breaking vacuum, using a metallic connecting strap and grounding loop to electrically couple the deposition ring with a lift-pin plate, enabling plasma cleaning without resputtering the metal film, thus maintaining chamber integrity and uptime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma cleaning is performed to remove organic residues from chamber components, then cleaning effectiveness is improved, but metallic material may be resputtered throughout the chamber causing damage and reducing chamber uptime
Solution Approach 1:
A deposition ring is introduced as an intermediary component that sacrificially accumulates metallic deposits during PVD processing. The ring is positioned to intercept metal flux before it reaches critical chamber components. During plasma cleaning, the ring is electrically isolated while other components are grounded, allowing selective cleaning without resputtering the sacrificial deposits.
Solution Approach 2:
The electrical state parameter of chamber components is dynamically changed between processing and cleaning modes. During PVD, the deposition ring is grounded to attract metal deposits. During plasma cleaning, the ring is electrically isolated (floating potential) while other components remain grounded, creating a potential difference that prevents resputtering of metallic material during the cleaning process.
2Reliability
If the chamber is vented to perform plasma cleaning and replace deposition rings, then complete cleaning is achieved, but chamber downtime increases significantly
Solution Approach 1:
The deposition ring enables continuous operation by allowing plasma cleaning to be performed without venting the chamber. The ring remains in place throughout multiple processing cycles, accumulating deposits gradually. When cleaning is needed, the ring is electrically isolated and the chamber undergoes plasma cleaning while maintaining vacuum, eliminating the need to break vacuum for ring replacement and enabling continuous chamber utilization.
Solution Approach 2:
The deposition ring serves itself by sacrificially accumulating all metallic deposits that would otherwise contaminate critical chamber components. The ring automatically performs the cleaning function for the rest of the chamber through selective electrical isolation during plasma cleaning, eliminating the need for manual intervention or chamber venting.
3Object-affected harmful factors
If the deposition ring is electrically isolated during plasma cleaning, then resputtering of metallic material is prevented, but the metal film on the ring remains charged
Solution Approach 1:
Before plasma cleaning begins, the deposition ring is electrically isolated by raising it to a floating potential. This preliminary action prevents charge accumulation during the cleaning process. The ring is positioned on insulating support structures that are established before cleaning, ensuring that when plasma is ignited, electrons cannot accumulate on the ring surface, maintaining electrical stability throughout the cleaning operation.
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
Enables effective removal of contaminants from PVD chamber components without breaking vacuum, preventing resputtering of metallic material and reducing downtime by allowing for in-situ plasma cleaning, thereby increasing chamber uptime and maintaining component functionality.
Implementation Method 1
removing contaminants from the chamber with a plasma formed in the chamber
Implementation Method 2
Atoms from the sputtering target may eject or sputter from the sputtering target and deposit a metal film on the substrate
Data Source
AI summary
Methods and apparatus for in-situ plasma cleaning of a deposition chamber are provided. In one embodiment a method for plasma cleaning a deposition chamber without breaking vacuum is provided. The method comprises positioning a substrate on a susceptor disposed in the chamber and circumscribed by an electrically floating deposition ring, depositing a metal film on the substrate and the deposition ring in the chamber, grounding the metal film deposited on the deposition ring without breaking vacuum, and removing contaminants from the chamber with a plasma formed in the chamber without resputtering the metal film on the grounded deposition ring and without breaking vacuum.