Protective Edge Layer on Silicon Epitaxial Substrates for Defect Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
III-V compound materials epitaxially grown on silicon substrates are prone to defects such as meltback, cracks, and pits, leading to poor quality in high-temperature, high-frequency, and high-power electronic devices.
Innovation Solution
A silicon substrate with a protective layer is manufactured, featuring a thicker middle part and thinner edge part with differing crystal orientations, where a covering layer is formed on the edge part and polished to create a protective layer, using materials like silicon dioxide or silicon nitride to prevent defect propagation during high-temperature processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If III-V compound materials are epitaxially grown on a silicon substrate, then high-temperature, high-frequency and high-power electronic devices can be manufactured, but defects such as meltback, cracks, particles and pits occur resulting in poor quality
Solution Approach 1:
The silicon substrate is divided into a middle part and an edge part with different thicknesses and crystal orientations. The middle part has a greater thickness and a to-be-grown surface with a specific crystal orientation, while the edge part has a smaller thickness and different crystal orientation, allowing different regions to serve different functions in preventing defects
Solution Approach 2:
Different regions of the substrate are given different properties: the middle part has optimized thickness and crystal orientation for epitaxial growth, while the edge part has reduced thickness and different crystal orientation to prevent defect propagation, with a protective covering layer applied specifically to the edge part
2Reliability
If a covering layer is formed on the edge part to prevent defect extension, then defect propagation is blocked, but the substrate structure becomes more complex
Solution Approach 1:
A protective covering layer is formed on the edge part of the silicon substrate before the epitaxial growth process. This preliminary protective measure prevents defects from the edge part from extending to the middle part during high-temperature processing, avoiding the need for complex defect repair processes later
Solution Approach 2:
The covering layer acts as an intermediary protective barrier between the edge part and the middle part of the substrate. Materials such as silicon dioxide, silicon nitride, or aluminum oxide are deposited on the edge part to block the propagation of defects while allowing the epitaxial growth process to proceed normally on the middle part
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 protective layer effectively prevents defects in the edge part from extending to the middle part, enhancing the quality of III-V compound materials by reducing defects and maintaining material integrity during high-temperature processing.
Implementation Method 1
the covering layer is formed through thermal oxidation of the silicon substrate
Implementation Method 2
the covering layer is formed through deposition including: physical vapor deposition
Implementation Method 3
the covering layer is formed through deposition including: chemical vapor deposition
Implementation Method 4
the covering layer is formed through deposition including: plasma enhanced chemical vapor deposition
Data Source
AI summary
The present application provides a substrate and a manufacturing method therefor. The substrate includes a silicon substrate and a protective layer, the silicon substrate includes a middle part and an edge part, and a thickness of the middle part is greater than a thickness of the edge part. The middle part has a to-be-grown surface, and a crystal orientation of the to-be-grown surface is different from a crystal orientation of surface of the edge part. The protective layer covers the edge part and is configured to prevent defects in the edge part from extending to the middle part during high-temperature processing.