Dual-Body Susceptor with Rotatable Alignment for Epitaxial Growth
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Solution Overview
Problem
Current epitaxial methods for semiconductor wafer fabrication face issues such as auto-doping, haloing, thermal stress, and susceptor wear, which degrade wafer quality and increase operational costs due to thermal stress and susceptor replacement needs.
Innovation Solution
A susceptor design with a dual-body structure featuring holes in specific configurations and arrangements to reduce auto-doping, haloing, and thermal stress, allowing for selective gas flow and reducing the need for full susceptor replacement by enabling separate replacement of the second body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a susceptor is used to hold the wafer during high temperature epitaxial growth, then the wafer can be heated to grow epi-layer, but thermal stress causes slip dislocation and increases surface roughness
Solution Approach 1:
The susceptor is divided into two separable bodies: a first body that remains fixed and a second body that can be replaced. This segmentation allows the wear-prone second body to be replaced independently, maintaining susceptor performance and reducing thermal stress effects on the wafer surface quality.
Solution Approach 2:
The susceptor design incorporates a replaceable second body that can be dynamically exchanged when worn. This dynamic replacement capability ensures the susceptor maintains optimal thermal and mechanical properties throughout operation, preventing degradation that would cause slip dislocation and surface roughness.
2Temperature
If a susceptor is used during epitaxial growth, then wafer heating is enabled, but the susceptor wears from friction and requires replacement
Solution Approach 1:
The susceptor is segmented into a first body and a second body that can be separated and replaced independently. The second body, which contacts the wafer and experiences friction, can be replaced without replacing the entire susceptor, thereby extending the overall service life while maintaining heating capability.
Solution Approach 2:
The design allows the worn second body to be discarded and replaced, while the first body is retained and reused. This selective replacement strategy recovers the durable first body and replaces only the consumable second body, optimizing resource utilization and reducing operational costs.
3Quantity of substance
If ions migrate between susceptor and wafer surface, then epitaxial growth occurs, but auto-doping degrades wafer quality
Solution Approach 1:
The design extracts the problematic second body as a separate, replaceable component. By removing and replacing this body, accumulated dopants can be eliminated, preventing auto-doping while maintaining the epitaxial growth function. This separation allows the growth function to be preserved while the contamination issue is addressed through replacement.
4Reliability
If cleaning gas is used to remove oxide layer, then wafer cleaning is performed, but haloing occurs due to incomplete removal
Solution Approach 1:
By extracting the second body as a replaceable component, the system addresses incomplete cleaning through physical replacement rather than relying solely on cleaning gas effectiveness. This ensures that any contamination or oxide layer remnants are removed by replacing the affected susceptor component.
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 effectively controls slip dislocation, edge stress, minority carrier lifetime, and auto-doping, while decreasing the operational costs of the epitaxial reactor by reducing wear and maintenance needs.
Implementation Method 1
A process of forming a high purity crystalline layer with crystal orientations aligned on a surface of a single crystalline silicon wafer grown using the Czochralski method is referred to as an epitaxial growth method... performed by a reactor which operates under high temperature conditions and which includes a susceptor on which a wafer is placed to grow an epi-layer
Implementation Method 2
A susceptor design with a dual-body structure featuring holes in specific configurations and arrangements to reduce auto-doping, haloing, and thermal stress, allowing for selective gas flow
Implementation Method 3
Another drawback relates to the heat generated from a heating source during chip fabrication. This heat places thermal stress on the wafer, which, in turn, may cause slip dislocation and increase surface roughness of a rear surface of the wafer... A susceptor design with a dual-body structure featuring holes in specific configurations and arrangements to reduce auto-doping, haloing, and thermal stress
Data Source
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AI summary
A susceptor includes a first body including a plurality of first holes and a second body including a plurality of second holes. According to one arrangement, the second body is spaced from the first body to form a gap which allows a gas to pass from the second holes to the first holes. According to this or another arrangement, the first body is removably or rotatably coupled to the second body, or both. Rotation of the second body by a first amount or in a first direction brings at least one first hole in alignment with at least one second hole. And, rotation of the second body by a second amount or in a second direction causes a misalignment to occur between these holes.