Diamond Substrate Manufacturing via Patterned Growth
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Solution Overview
Problem
The selective growth process for diamond substrates reduces dislocation defects but is prone to generating abnormal growth particles, rendering the substrates unsuitable for semiconductor devices.
Innovation Solution
A method involving heteroepitaxial growth on a foundation surface of materials like iridium, rhodium, or platinum, with CF4 plasma removal of foreign substances from patterned diamond walls, and optimizing pattern gap ratios and bottom portion preparation to minimize stress and abnormal growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If selective growth process is used to reduce dislocation defects, then dislocation defect density is reduced, but abnormal growth particles are generated
Solution Approach 1:
The patent applies preliminary action by performing pattern formation on the diamond surface before the selective growth process. The patterned structure with controlled gap widths is created in advance to guide the subsequent lateral overgrowth, ensuring that diamond grows selectively in desired regions while preventing abnormal particle formation during the growth process.
Solution Approach 2:
The patent implements local quality by creating patterns with specific local geometries (gap widths of 1-10 μm) on the diamond surface. These locally varied structures control where lateral overgrowth occurs, allowing dislocation defects to be reduced in specific regions while maintaining control over the growth process to prevent abnormal particle generation.
2Area of stationary object
If heteroepitaxial growth is used to obtain large-area substrates, then substrate area is increased, but dislocation defects increase due to lattice mismatch
Solution Approach 1:
The patent applies segmentation by dividing the heteroepitaxial growth process into distinct stages: initial epitaxial growth to form a continuous layer, followed by pattern formation, and then selective lateral overgrowth. This segmented approach allows the large substrate area to be maintained while controlling dislocation propagation through the patterned regions.
Solution Approach 2:
The patent uses an intermediary patterned structure as a mediator between the heteroepitaxial diamond layer and the selective growth regions. The patterned gaps (1-10 μm wide) act as intermediaries that guide dislocation behavior, allowing the large-area substrate to maintain low dislocation density in the final product by controlling where growth occurs.
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 results in diamond substrates with reduced dislocation defects and suppressed abnormal growth particles, enabling the production of high-quality, large-area substrates for semiconductor applications.
Implementation Method 1
a foreign substance adhered on the wall of the patterned diamond is removed, for instance by using CF 4 plasma
Implementation Method 2
it has been investigated to produce a diamond substrate by heteroepitaxial growth, in which diamond is grown on the other material
Implementation Method 3
to produce epitaxial diamond by a direct current plasma CVD method
Implementation Method 4
to subject the surface to treatment for generating a diamond nuclei
Data Source
Figure 1(a)~1(i)
Figure 2(a)~2(i)
Figure 3~4
AI summary
The present invention provides a method for manufacturing a diamond substrate, including: a first step of preparing patterned diamond on a foundation surface, a second step of removing a foreign substance adhered on a wall of the patterned diamond prepared in the first step, and a third step of growing diamond from the patterned diamond prepared in the first step to form the diamond in a pattern gap of the patterned diamond prepared in the first step. There can be provided a method for manufacturing a diamond substrate with few dislocation defects, in which generation of abnormal growth particles are suppressed.