Patterned Substrate Preparation for Epitaxial Stress Relief
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Solution Overview
Problem
Existing methods for growing III-V compound semiconductors on substrates like sapphire, silicon, and silicon carbide face challenges such as lattice and thermal stress mismatches, leading to warping, cracking, and high threading dislocation densities, which affect material performance and increase production costs.
Innovation Solution
A substrate with a base substrate and a thin film layer having recessed holes formed on its surface, allowing stress release during epitaxial growth, reducing defects and cracks by forming the holes using a corrosive gas in a reaction container.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If photolithography or etching is used to make patterned substrates, then stress control is improved, but device complexity and production cost increase
Solution Approach 1:
The substrate surface is pre-modified by forming recessed holes before epitaxial growth. This preliminary action creates stress relief pathways in advance, preventing warping and cracking during subsequent epitaxial layer growth without requiring complex post-processing photolithography or etching steps.
Solution Approach 2:
The substrate surface is transformed into a porous structure with recessed holes distributed across the surface. These pores provide stress relief during epitaxial growth, allowing the system to accommodate lattice mismatch and thermal stress without compromising structural integrity, thereby simplifying the overall process.
2Stability of the object's composition
If photolithography or etching is used to make patterned substrates, then stress control is improved, but production cost increases
Solution Approach 1:
The substrate surface is pre-modified by forming recessed holes before epitaxial growth. This preliminary action creates stress relief pathways in advance, preventing warping and cracking during subsequent epitaxial layer growth without requiring complex post-processing photolithography or etching steps.
Solution Approach 2:
The substrate surface is transformed into a porous structure with recessed holes distributed across the surface. These pores provide stress relief during epitaxial growth, allowing the system to accommodate lattice mismatch and thermal stress without compromising structural integrity, thereby simplifying the overall process.
3Shape
If a buffer layer is added in the middle of the epitaxial layer, then warping control is improved, but threading dislocation density increases
Solution Approach 1:
The substrate surface is pre-modified by forming recessed holes before epitaxial growth. This preliminary action creates stress relief pathways in advance, preventing warping and cracking during subsequent epitaxial layer growth without requiring complex post-processing photolithography or etching steps.
Solution Approach 2:
The substrate surface is transformed into a porous structure with recessed holes distributed across the surface. These pores provide stress relief during epitaxial growth, allowing the system to accommodate lattice mismatch and thermal stress without compromising structural integrity, thereby simplifying the overall process.
4Shape
If a buffer layer is added in the middle of the epitaxial layer, then warping control is improved, but epitaxial layer thickness is limited
Solution Approach 1:
The substrate surface is pre-modified by forming recessed holes before epitaxial growth. This preliminary action creates stress relief pathways in advance, preventing warping and cracking during subsequent epitaxial layer growth without requiring complex post-processing photolithography or etching steps.
Solution Approach 2:
The substrate surface is transformed into a porous structure with recessed holes distributed across the surface. These pores provide stress relief during epitaxial growth, allowing the system to accommodate lattice mismatch and thermal stress without compromising structural integrity, thereby simplifying the overall process.
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 method simplifies and lowers the cost of substrate preparation by forming recessed holes without complex etching, effectively reducing stress-related defects and improving semiconductor quality and performance.
Implementation Method 1
conducting a corrosive gas into the reaction container to form one or more recessed holes in at least a part of the exposed surface
Implementation Method 2
conducting a metal source into the reaction container, and forming a thin film layer on a surface of the base substrate
Data Source
AI summary
Disclosed is a method for preparing a substrate relate to the field of semiconductors. The method comprises the following steps: S1, providing a reaction container in which a base substrate is mounted; S2, conducting a metal source into the reaction container, and forming a thin film layer on a surface of the base substrate, wherein a part of a surface of the base substrate is covered by the thin film layer, so that the base substrate is provided with an exposed surface that is not covered by the thin film layer; and S3, conducting a corrosive gas into the reaction container to form one or more recessed holes in at least a part of the exposed surface.