Diamond Layer Growth by Scanning Microwave Plasma CVD
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Solution Overview
Problem
Conventional microwave plasma CVD methods are limited in irradiating area, restricting the growth of diamond substrates to diameters smaller than 300 mm, hindering the application of diamond in large-diameter semiconductor devices due to limitations in microwave irradiation.
Innovation Solution
A method involving the parallel movement of the substrate or microwave plasma irradiation position relative to the substrate surface during diamond growth in a microwave plasma CVD apparatus, combined with subsequent hot filament CVD for further thickness, enabling large-diameter single crystal diamond layer formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional microwave plasma CVD method with fixed irradiation area is used, then single crystal diamond growth is achieved, but substrate diameter is limited to less than 300 mm
Solution Approach 1:
The patent applies the dynamics principle by making the microwave irradiation system movable. Specifically, the microwave plasma irradiation position is moved in a direction parallel to the substrate surface during diamond layer growth, allowing the limited microwave irradiation area to cover the entire large-diameter substrate over time, thereby enabling growth on substrates with diameters of 300 mm or more
2Manufacturing precision
If microwave plasma is irradiated directly downward on stationary substrate, then single crystal growth is achieved, but uniform growth across large area is difficult
Solution Approach 1:
The patent moves the microwave plasma irradiation position parallel to the substrate surface during growth, ensuring that the entire substrate area receives uniform plasma exposure over time. This dynamic irradiation approach maintains consistent growth conditions across the large substrate area, achieving uniform diamond layer growth
3Length of stationary object
If substrate is stationary during microwave plasma irradiation, then simple apparatus operation is achieved, but large-diameter substrate growth is limited
Solution Approach 1:
The patent introduces a moving mechanism for the microwave plasma irradiation system that can traverse across the substrate surface. This adds controlled motion capability to the apparatus, enabling coverage of large-diameter substrates while maintaining relatively simple system architecture through straightforward mechanical translation of the irradiation source
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
Enables the growth of large-diameter single crystal diamond layers with reduced defects, suitable for use as heat sinks in integrated circuits, by uniformly irradiating microwave plasma and promoting horizontal growth.
Implementation Method 1
decomposing or activating the raw material gas (reaction gas) by thermal decomposition or plasma
Implementation Method 2
decomposing or activating the raw material gas (reaction gas) by thermal decomposition or plasma
Implementation Method 3
a vapor phase growth method... CVD (chemical vapor deposition method)
Data Source
AI summary
The present invention is a method for growing a diamond layer by a microwave plasma CVD method, including: a step of placing a substrate 2 in a reaction vessel 1 of a microwave plasma CVD apparatus 10; a step of introducing a raw material gas (reaction gas) 6 into the reaction vessel 1; and a step of growing a diamond layer on a surface of the substrate 2 by irradiating microwave plasma on the surface of the substrate 2, wherein the step of growing the diamond layer includes at least one of moving the substrate 2 in a direction parallel to the surface of the substrate 2 and moving an irradiation position of the microwave plasma in a direction parallel to the surface of the substrate 2. Thereby, a large-diameter diamond substrate is provided.