Dual-Station Vacuum Processor Offset Pumping Uniformity
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Solution Overview
Problem
Dual-station vacuum processors face challenges in achieving uniform pressure and flow rate across 0°-360° due to offset-pumping, leading to ununiform etching and difficulty in balancing high throughput with high performance.
Innovation Solution
A dual-station vacuum processor with a compensation mechanism, including a damper and baffle plate with transversely extending ribs, which increases flow resistance near the pumping port and lengthens the gas flow path to balance pumping rates, and a plasma restraint ring for further uniformity, creating a second atmospheric environment channel for cable isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If offset-pumping is used in dual-station vacuum processor, then throughput is improved by sharing vacuum pump between two chambers, but pressure uniformity deteriorates causing ununiform etching
Solution Approach 1:
The patent introduces a damper structure with specific geometric parameters (thickness, length, position) that creates localized flow resistance in the region near the pumping port. This local modification to the flow characteristics compensates for the asymmetric pumping effect, ensuring uniform pressure distribution across the substrate while maintaining the offset-pumping configuration for high throughput
Solution Approach 2:
The damper acts as an intermediary element between the pumping port and the chamber interior. It mediates the gas flow by introducing controlled resistance that balances the asymmetric pumping effect, allowing the offset-pumping port to serve both chambers effectively while maintaining pressure uniformity
2Manufacturing precision
If pumping port is positioned at bottom center for single station, then pressure uniformity is improved, but space utilization deteriorates in dual-station configuration
Solution Approach 1:
The patent deliberately employs asymmetric positioning of the pumping port at the bottom center of the dual-station chamber, combined with symmetric placement of dampers in both stations. This asymmetric configuration optimizes space utilization for dual-station operation while the symmetric damper compensation restores pressure uniformity across both chambers
3Productivity
If vacuum volume is increased for dual-station processor, then throughput is improved, but pumping rate deteriorates making it difficult to reach required vacuum degree
Solution Approach 1:
The damper introduces localized flow resistance that redistributes the gas flow paths within the chamber. This local modification effectively increases the pumping speed at critical regions by balancing the asymmetric flow patterns, enabling the system to achieve required vacuum degrees despite the larger vacuum volume of dual-station configuration
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 effectively ameliorates the impact of offset-pumping on uniformity, achieving pressure uniformity <1% and flow rate uniformity <20%, maximizing space utilization and ensuring high-performance etching processes.
Implementation Method 1
a damper is provided in an adjustment region 61 in each vacuum processing chamber; the damper has a set thickness in a vertical direction... flow resistance may be increased at a position proximal to the pumping port
Implementation Method 2
a longitudinally extending baffle plate is provided on a base plate of each vacuum processing chamber... lengthens the gas flow path to balance pumping rates
Implementation Method 3
an offset-pumping port and a vacuum pump common to and communicating with the two vacuum processing chambers
Data Source
AI summary
The present invention relates to a dual-station vacuum processor that pumps uniformly, comprising two vacuum processing chambers that may act as a process processing chamber, and an offset-pumping port and a vacuum pump which are common to and communicate with the two vacuum processing chambers, wherein a damper having a set thickness in a vertical direction is provided in a region proximal to the offset-pumping port in each vacuum processing chamber, so as to lower a pumping rate of gas at the pumping port proximal end and balance the pumping rate with the pumping rate of the gas at the pumping port distal end, thereby ameliorating the impact of chamber offset on the uniformity process processing. The present invention may further provide, in a rib as the damper, a channel in communication with the atmospheric environment outside of the chamber, so as to facilitate connection between a cable pipeline in the chamber and the outside.