Shower Plate Surface Design for Plasma CVD Film Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for improving uniformity of film thickness in semiconductor manufacturing often require changing process conditions or introducing new hardware, which limits usable conditions and increases development costs, and empirical approaches to modifying the shower plate shape are inefficient.
Innovation Solution
A method for designing a shower plate with convex, concave, and flat regions defined by intersection points and quadratic functions, allowing for the adjustment of the surface configuration to achieve improved in-plane uniformity without altering film forming conditions, by overlaying secondary equations on a base convex equation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If process conditions are changed to improve uniformity, then film thickness uniformity is improved, but usable conditions are significantly limited
Solution Approach 1:
The shower plate surface is designed with different regions (convex, concave, flat) having different geometries to locally control plasma distribution and film deposition patterns, achieving uniformity without restricting process conditions
Solution Approach 2:
Instead of adjusting process parameters (1D optimization), the invention modifies the spatial geometry of the shower plate surface (adding dimensional complexity) to control film uniformity, thereby preserving process condition flexibility
2Manufacturing precision
If new hardware is introduced to improve uniformity, then film thickness uniformity is improved, but film quality changes and required thickness is not satisfied
Solution Approach 1:
The invention changes the geometric parameters of the existing shower plate (surface profile, curvature radii, region dimensions) rather than introducing new hardware, thereby maintaining film quality while achieving uniformity through mathematical optimization of surface equations
3Manufacturing precision
If empirical methods are used to determine shower plate shape, then favorable results can be achieved, but many prototypes must be created increasing development cost
Solution Approach 1:
The invention performs preliminary mathematical modeling and simulation to determine the optimal shower plate shape equations before manufacturing, eliminating the need for multiple prototype iterations and reducing development time
Solution Approach 2:
Instead of creating multiple physical prototypes through empirical trial-and-error, the invention uses mathematical equations to create a virtual model that predicts performance, allowing optimization without physical iteration
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 approach significantly improves film thickness uniformity, reducing it to less than 1% while maintaining equivalent film quality properties, and allows for repeated adjustments to achieve satisfactory film distribution.
Implementation Method 1
a shower plate having a convex surface configured by a convex equation L which is a function of a radius R: (b) forming a film on a wafer using the shower plate in the plasma CVD apparatus... a wafer is placed on a susceptor, above which the shower plate is disposed substantially in parallel for discharging a gas therethrough and generating a plasma between the susceptor and the shower plate
Implementation Method 2
forming a film on a wafer using the shower plate in the plasma CVD apparatus
Data Source
AI summary
A method of designing a shower plate for a plasma CVD apparatus includes (a) providing a shower plate having a convex surface configured by a convex equation; (b) forming a film on a wafer using the shower plate in the plasma CVD apparatus; (c) determining a distribution of thickness of the film formed on the wafer by dividing a diametrical cross section of the film into multiple regions; (d) determining at least one secondary equation; and (e) designing a surface configuration of the shower plate by overlaying the secondary equation on the convex equation.