Gas Shower Head with Variable Hole Density for CVD Film Uniformity
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Solution Overview
Problem
In the semiconductor industry, chemical vapor deposition (CVD) processes face challenges in achieving film profile uniformity, particularly for larger wafer sizes, leading to issues like protrusions and depressions, and insufficient edge support during wafer thinning operations due to uneven film thickness.
Innovation Solution
A film formation apparatus with a gas shower head featuring varying hole densities in central and peripheral regions, where the peripheral region has a higher hole density, is used to deposit a thicker film edge, providing enhanced support during wafer thinning and improving process yield by mitigating edge peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If chemical vapor deposition (CVD) process is used for larger wafer sizes, then film deposition coverage is improved, but film profile uniformity deteriorates leading to protrusions and depressions
Solution Approach 1:
The shower head is designed with non-uniform hole density distribution, where the peripheral region has a higher hole density than the central region. This local variation in hole density creates different gas flow characteristics in different regions, enabling better control over film deposition uniformity across the wafer surface, particularly addressing the edge thickness issue in larger wafers
2Ease of manufacture
If conventional shower head with uniform hole density is used, then manufacturing simplicity is maintained, but film thickness uniformity deteriorates at wafer edges
Solution Approach 1:
The shower head incorporates regions with different hole densities - a central region with lower hole density and a peripheral region with higher hole density. This local differentiation in hole density is designed to compensate for the natural tendency of film deposition to be thinner at the edges, thereby achieving more uniform overall film thickness across the wafer
3Productivity
If film deposition is performed on larger wafers, then production capacity is improved, but edge support during wafer thinning deteriorates due to insufficient film thickness
Solution Approach 1:
By concentrating higher hole density in the peripheral region of the shower head, the design ensures enhanced gas flow and reactant delivery to the wafer edge regions during deposition. This results in thicker and more robust film formation at the wafer edges, providing necessary mechanical support during subsequent wafer thinning operations while maintaining compatibility with larger wafer sizes for improved production capacity
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 apparatus ensures a thicker film edge, enhancing substrate strength and preventing peeling, thereby improving the reliability and yield of semiconductor processing by maintaining uniformity and support across the wafer edge.
Implementation Method 1
In the semiconductor industry, apparatus, such as chemical vapor deposition (CVD) apparatus, for forming films has been used to deposit various layers over the substrate
Data Source
AI summary
A gas shower head includes a plate, a plurality of central holes disposed in a central region of the plate, and a plurality of peripheral holes disposed in a peripheral region of the plate. The central holes are configured to form a first portion of a material film, and the peripheral holes are configured to form a second portion of the material film. A hole density in the peripheral region is greater than a hole density in the central region. The first portion of the material film includes a first thickness corresponding to the hole density in central region, and the second portion of the material film includes a second thickness corresponding to the hole density in peripheral region and greater than the first thickness.