Dual Rotatable Shields for Multi-Cathode PVD Chamber Deposition
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Solution Overview
Problem
In multi-cathode PVD chambers, there is unwanted deposition on substrates during pressure reduction and cross-contamination between targets due to simultaneous deposition of materials from multiple targets, requiring frequent chamber venting and hardware replacement.
Innovation Solution
The implementation of dual rotatable shields in a multi-cathode processing chamber, where a first rotatable shield with a conical portion and holes is coupled to a shaft, and a second rotatable shield is concentric with the first, allowing independent rotation to selectively expose the substrate to desired cathodes and prevent unwanted deposition, thereby minimizing cross-contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple targets are used in a multi-cathode PVD chamber for depositing different materials, then material diversity and deposition capability are improved, but cross-contamination between targets and unwanted deposition on substrates occur
Solution Approach 1:
The shielding system is divided into multiple independent rotatable shields (first shield, second shield, third shield) that can be individually positioned to selectively block or expose different cathodes. Each shield has holes at specific positions that can be aligned with desired cathodes, allowing precise control over which material sources are active, thereby preventing cross-contamination while maintaining multi-material deposition capability.
Solution Approach 2:
The shields are designed to rotate independently around the chamber axis, transforming a static shielding configuration into a dynamic one. This rotation capability allows the system to switch between different cathode combinations during the deposition process, enabling sequential deposition of multiple materials without venting the chamber, thus eliminating cross-contamination while preserving deposition versatility.
2Productivity
If simultaneous deposition from multiple targets is performed, then deposition speed and productivity are improved, but cross-contamination between materials increases
Solution Approach 1:
The system enables periodic switching between different cathode configurations by rotating the shields to different angular positions. During a deposition cycle, the shields can be positioned to expose one or two cathodes at a time in a controlled sequence, allowing materials to be deposited periodically rather than simultaneously, thus maintaining high productivity while preventing cross-contamination through temporal separation of material deposition.
3Manufacturing precision
If chamber venting is performed frequently to prevent cross-contamination, then substrate purity is improved, but processing time and productivity decrease
Solution Approach 1:
The rotatable shields act as intermediary components between the cathodes and the substrate. By positioning these shields strategically with holes aligned to specific cathodes, the system can selectively block unwanted material flux from reaching the substrate while allowing desired materials to deposit. This intermediary shielding mechanism maintains substrate purity without requiring chamber venting, thus preserving processing time and productivity.
4Manufacturing precision
If hardware replacement is performed frequently to address contamination, then substrate purity is improved, but device complexity and operational time increase
Solution Approach 1:
The rotatable shield system provides self-service functionality by automatically controlling which cathodes are exposed to the substrate through rotation. The holes in each shield are positioned to align with specific cathodes, allowing the system to self-regulate material deposition without manual intervention or hardware replacement. This automated shielding mechanism maintains substrate purity while reducing operational complexity and processing time.
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 reduces unwanted deposition and cross-contamination, allowing for sequential deposition without venting the chamber, enhancing process control and throughput while maintaining substrate purity.
Implementation Method 1
Physical vapor deposition (PVD) chambers are often used in the semiconductor industry. PVD in semiconductor fabrication is typically performed with a target made of a desired film material.
Implementation Method 2
a conical portion extending downward and radially outward from the base
Data Source
AI summary
Embodiments of a process kits for use in a process chamber are provided herein. In some embodiments, a process kit for use in a multi-cathode processing chamber includes: a first rotatable shield coupled to a first shaft, wherein the first rotatable shield includes a base, a conical portion extending downward and radially outward from the base, and one or more holes formed through the conical portion, wherein no two holes of the one or more holes are diametrically opposed; and a second rotatable shield coupled to a second shaft concentric with the first shaft, wherein the second rotatable shield is disposed in the first rotatable shield, and wherein the first rotatable shield is configured to rotate independent of the first rotatable shield.