Process Chamber Pump Liner for Uniform Gas Flow and Heat Loss
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Solution Overview
Problem
Current pump liners in processing chambers, such as ALD and CVD chambers, suffer from side-to-side variations in temperature and gas flow, leading to wafer planar non-uniformity due to asymmetric heat loss and flow conductance, which is challenging to address with existing optimization methods that require individualized designs and trial-and-error approaches.
Innovation Solution
A pump liner design with a ring-shaped body featuring an upper and lower portion separated by an annular partition, including circumferentially spaced apertures and a slit valve opening, which self-adjusts flow conductance using spring-actuated valve assemblies and variable slit valve openings to achieve uniform gas distribution and symmetric heat loss, reducing side-to-side variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If variable size openings are used to choke gas flow toward pumping ports, then gas flow uniformity is improved, but device complexity increases and manufacturing cost increases
Solution Approach 1:
The patent applies local quality by positioning pump ports at specific locations around the pump liner perimeter and configuring apertures in the edge ring with specific sizes and distributions tailored to each local region. This local optimization ensures uniform gas flow distribution to each pump port while accounting for asymmetric pumping conditions, achieving improved gas flow uniformity without requiring variable size openings throughout the entire liner.
2Manufacturing precision
If individualized pumping liner designs are created through simulation and wafer deposition mapping, then flow uniformity is improved, but productivity decreases and loss of time increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring the edge ring with optimally sized and positioned apertures during manufacturing, based on anticipated asymmetric pumping conditions. This pre-optimization eliminates the need for time-consuming trial-and-error testing and individualized design iterations, significantly reducing lead time while maintaining flow uniformity.
Solution Approach 2:
The patent applies self-service through the self-adjusting flow conductance mechanism where spring-actuated valve assemblies automatically regulate gas flow to each pump port based on local pressure conditions. This self-regulating behavior achieves flow uniformity without requiring external optimization efforts, simulation studies, or trial-and-error testing, thereby improving productivity and reducing time losses.
3Ease of operation
If asymmetric pumping configuration is used with fore lines located off-axis, then ease of operation is improved, but temperature uniformity deteriorates and gas flow uniformity deteriorates
Solution Approach 1:
The patent applies asymmetry by deliberately configuring the edge ring with non-uniform aperture distributions and sizes that correspond to the asymmetric pump port locations. This asymmetric design compensates for the asymmetric pumping configuration, ensuring that each region of the process chamber receives appropriate gas flow and heat distribution, thereby maintaining temperature uniformity and gas flow uniformity despite the off-axis fore line location.
4Ease of manufacture
If pump ports are located closer to some openings than others, then ease of manufacture is improved, but gas flow conductance uniformity deteriorates
Solution Approach 1:
The patent applies local quality by configuring apertures in the edge ring with specific sizes and distributions tailored to each local region's distance from pump ports. Regions closer to pump ports have differently sized apertures compared to regions farther away, ensuring that each location contributes appropriately to uniform overall gas flow conductance despite variations in pump port proximity.
Data Source
AI summary
Embodiments of the present disclosure are related to directed to a pump liner for a process chamber. The pump liner is aligned with particular components in the process chamber so that there is an upper gap and a lower gap between the pump liner and the particular processing chamber components (e.g., an edge ring). The pump liner advantageously reduces side to side variation in temperature and gas flow based on its alignment with particular components in the process chamber (e.g., the edge ring) and the size of the upper gap and the lower gap. Some embodiments advantageously provide better precursor flow distribution for various process spacing between the showerhead and wafer.