Shadow Frame Varied Profile for Deposition Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current shadow frames in plasma processing chambers cause deposition non-uniformity, particularly at the edges and corners of substrates, leading to reduced deposition on the periphery.
Innovation Solution
A shadow frame design featuring two opposing major side frame members coupled with minor side frame members and corner brackets that include orthogonal legs and a rounded corner, along with a recessed area and sloped planar surfaces, to minimize shadowing and enhance uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional shadow frame with straight edges is used, then the substrate periphery is protected from deposition, but deposition non-uniformity occurs at the edges and corners due to shadowing effects
Solution Approach 1:
The shadow frame incorporates rounded corners instead of sharp 90-degree angles. This curvature modification eliminates the shadowing effect that occurs at sharp corners, allowing plasma and deposition materials to reach the substrate edges and corners uniformly. The rounded profile ensures consistent deposition thickness across the entire substrate periphery while maintaining the protective function of the shadow frame.
Solution Approach 2:
The shadow frame features a non-uniform profile where the distance from the substrate edge varies along the frame perimeter. Specifically, the frame is positioned closer to the substrate at corners and edges compared to the mid-sections of each side. This local variation in positioning compensates for the shadowing effect, ensuring uniform deposition coverage at critical areas while maintaining appropriate clearance elsewhere.
2Object-affected harmful factors
If the shadow frame is positioned close to the substrate to prevent deposition, then edge protection is improved, but shadowing effects cause non-uniform deposition at the periphery
Solution Approach 1:
The rounded corner geometry allows the shadow frame to approach the substrate more closely at corner regions without creating shadowing effects. The curved profile enables plasma and deposition materials to reach the substrate edges uniformly, ensuring consistent deposition thickness while maintaining effective protection against unwanted peripheral deposition.
Solution Approach 2:
Instead of maintaining a uniform distance between the shadow frame and substrate throughout, the design inverts the approach by varying the distance locally - closer at corners and edges where shadowing is most problematic, and farther at mid-sections. This inverted positioning strategy optimizes deposition uniformity while maintaining protective coverage.
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 new shadow frame design improves amorphous silicon deposition uniformity by reducing edge lip shadowing and ensuring even coverage, increasing deposition thickness on the substrate edges and corners.
Implementation Method 1
Glass substrate processing techniques include plasma-enhanced chemical vapor deposition (PECVD)... The plasma is formed by introducing one or more process gases into the chamber and exciting the gases with an electrical field to cause dissociation of the gases into charged and neutral particles
Data Source
AI summary
Embodiments of the present disclosure generally relates a shadow frame including two opposing major side frame members adjacent to two opposing minor side frame members coupled together with a corner bracket, wherein the corner bracket includes a corner inlay having legs that extend in directions generally orthogonal to each other.