Dual-Plenum Showerhead Faceplate for Uniform Gas Distribution
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Solution Overview
Problem
Semiconductor processing showerheads face challenges in achieving uniform gas distribution across semiconductor substrates due to limitations in the design of faceplates, which affect the efficiency of gas delivery and plasma generation.
Innovation Solution
The faceplate design includes a dual-plenum structure with radially extending first channels and circumferentially arranged second channels, along with distinct gas distribution holes, optimized for uniform gas flow and plasma distribution, featuring chamfered edges and specific cross-sectional areas to enhance gas flow and radical delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional single-plenum showerhead design is used, then the structure is simple, but uniform gas distribution across the substrate is difficult to achieve
Solution Approach 1:
The faceplate is divided into two separate plenums (first plenum and second plenum) with distinct gas distribution channels and holes. The first plenum contains first channels and first gas distribution holes, while the second plenum contains second channels and second gas distribution holes. This segmentation allows independent optimization of gas flow paths for each plenum, enabling uniform gas distribution across different regions of the substrate without requiring a single complex integrated structure.
2Manufacturing precision
If gas distribution holes are distributed across the faceplate, then gas delivery is facilitated, but edge-to-center flow uniformity is compromised
Solution Approach 1:
Different regions of the faceplate are equipped with different types of gas distribution features optimized for their specific requirements. The first plenum with first channels and first gas distribution holes serves specific regions, while the second plenum with second channels and second gas distribution holes serves other regions. This local optimization allows each region to receive gas flow tailored to its specific needs, achieving edge-to-center uniformity while maintaining overall gas delivery efficiency.
3Manufacturing precision
If channels extend towards the center axis, then radial gas distribution is improved, but channel cross-sectional area must be reduced
Solution Approach 1:
The invention transitions from a single-plenum design to a dual-plenum three-dimensional structure. By stacking two plenums vertically (in the thickness direction of the faceplate), the system provides additional spatial dimensions for gas distribution. This allows channels in each plenum to extend towards the center axis with adequate cross-sectional areas, as the second plenum compensates for any flow distribution imbalances, thereby achieving radial uniformity without compromising channel volume.
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 design ensures uniform gas distribution and maximizes the delivery of free radicals across the substrate, improving semiconductor processing efficiency and plasma generation.
Implementation Method 1
a plurality of first channels within the volume extending from the outer surface towards the center axis... a plurality of second channels within the volume. Each second channel may travel in a substantially circumferential direction with respect to the center axis
Implementation Method 2
a plurality of first gas distribution holes, each first gas distribution hole fluidly connected within the volume to one or more of the first channels... a plurality of second gas distribution holes, each second gas distribution hole extending through the top surface and the bottom surface
Data Source
AI summary
A dual-plenum showerhead for semiconductor processing operations is provided. The showerhead may include a faceplate with two sets of gas distribution holes, each set fed by a separate plenum. One set of gas distribution holes may be through-holes in the faceplate of the showerhead and may allow gases trapped between the faceplate and a plasma dome to flow towards a wafer. The other set of gas distribution holes may distribute gas routed through passages or channels in the faceplate towards the wafer. The passages or channels in the faceplate may include radial channels and annular channels and may be fed from an annular gas distribution channel about the periphery of the faceplate.