Plasma-Exclusion Ring Geometry for Uniform Notched Wafer Processing
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Solution Overview
Problem
Existing substrate processing systems face challenges in achieving uniform etch and deposition rates at the notches of semiconductor wafers, leading to non-uniform surface topography and reduced yield due to variations in material removal and adhesion, which can result in voids during wafer-to-wafer bonding.
Innovation Solution
The introduction of a plasma-exclusion-zone ring with notches that match the profile of the wafer notches, featuring tapered and recessed surfaces to enhance plasma diffusion and uniformity, ensuring consistent etching and deposition rates across the wafer periphery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional substrate processing is used without plasma-exclusion-zone ring, then processing is simpler, but etch and deposition uniformity at wafer notches deteriorates
Solution Approach 1:
The plasma-exclusion-zone ring is divided into multiple segments with different surface characteristics. The ring includes a first portion with a first surface and a second portion with a second surface, creating distinct plasma interaction zones that address uniformity issues at different locations around the wafer periphery.
Solution Approach 2:
Different portions of the plasma-exclusion-zone ring are given different surface properties to create localized plasma exclusion effects. The first and second surfaces are configured to produce different plasma interaction patterns, allowing precise control of etch and deposition rates at specific notch locations.
2Manufacturing precision
If plasma diffusion is increased at wafer notches, then etch and deposition uniformity improves, but plasma control complexity increases
Solution Approach 1:
The plasma-exclusion-zone ring is positioned upstream of the wafer to pre-condition the plasma before it reaches the wafer periphery. By creating plasma exclusion zones in advance, the system achieves uniform material removal at notches without requiring complex real-time plasma control during the main processing step.
3Manufacturing precision
If plasma-exclusion-zone ring with tapered surfaces is used, then plasma diffusion uniformity improves, but manufacturing complexity of the ring increases
Solution Approach 1:
The plasma-exclusion-zone ring incorporates tapered surfaces and curved geometries to optimize plasma diffusion patterns. The first and second surfaces are configured with specific angles and curvatures that naturally guide plasma flow, achieving uniform diffusion without requiring additional active control mechanisms.
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 plasma-exclusion-zone ring improves etch and deposition uniformity at and near wafer notches, enhancing yield by maintaining consistent material removal and adhesion, thereby reducing voids and increasing the overall processing efficiency.
Implementation Method 1
featuring tapered and recessed surfaces to enhance plasma diffusion and uniformity
Implementation Method 2
plasma may be used to initiate chemical reactions
Data Source
AI summary
A plasma-exclusion-zone ring for a substrate processing system that is configured to process a substrate includes a ring-shaped body, an upper portion of the ring-shaped body, a base and a plasma-exclusion-zone ring notch. The upper portion of the ring-shaped body defines a radially inner surface and a top surface. The base of the ring-shaped body defines a radially outer surface, a first bottom surface extending radially inward from the radially outer surface, and a second bottom surface extending radially inward from the first bottom surface. The plasma-exclusion-zone ring notch is proportional to an alignment notch of the substrate. The first bottom surface is tapered and extends at an acute angle from the second bottom surface to the radially outer surface. The first bottom surface is configured to extend over and oppose a periphery of the substrate.