AlN-Buffered GaN Laminated Substrate for Low-Warp Epitaxy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to form a high-quality GaN layer on an underlying substrate with reduced thickness to minimize warping and maintain crystallinity, as thinner layers tend to deteriorate in quality and cause precision issues in semiconductor manufacturing.
Innovation Solution
A group III-nitride laminated substrate is created with an underlying substrate, a first layer of aluminum nitride, and a second layer of gallium nitride, where the GaN layer has a thickness of 10 μm or less, achieving high crystallizability and surface flatness through specific growth conditions and heat treatment, ensuring high in-plane uniformity and dopant concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the thickness of the GaN layer is reduced to minimize warping, then warping is reduced, but the quality of the GaN layer deteriorates
Solution Approach 1:
An aluminum nitride (AlN) layer is introduced as an intermediary between the underlying substrate and the GaN layer. This AlN layer serves as a buffer that improves the crystallinity and quality of the thin GaN layer, enabling high-quality GaN growth at reduced thicknesses (10 μm or less) while minimizing warping effects.
Solution Approach 2:
The invention changes the material parameter by using AlN instead of conventional buffer layers, and optimizes the thickness parameter of the GaN layer to 10 μm or less. This parameter change allows achieving both reduced warping and maintained quality through the combination of thin GaN layer and AlN buffer layer.
2Shape
If the thickness of the GaN layer is reduced, then warping is reduced, but crystallizability deteriorates
Solution Approach 1:
The AlN layer acts as an intermediary buffer layer that provides a suitable crystalline foundation for GaN growth. This intermediary structure enables atoms to arrange in proper crystalline order even when the GaN layer is thin, thereby maintaining crystallizability at reduced thicknesses.
Solution Approach 2:
The invention uses a composite structure consisting of AlN buffer layer and GaN layer. This composite material approach leverages the beneficial properties of both materials: AlN provides excellent lattice matching and thermal stability, while GaN provides the desired semiconductor properties, achieving both reduced warping and maintained crystallizability.
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 a GaN layer with improved crystallizability, surface flatness, and in-plane uniformity, reducing warping and enhancing semiconductor element performance while maintaining a thin thickness to prevent excessive warping.
Implementation Method 1
a first layer that is formed on the underlying substrate and is made of aluminum nitride; and a second layer that is formed on the first layer and is made of gallium nitride
Implementation Method 2
a half-value width of (0002) diffraction determined through X-ray rocking curve analysis is 100 seconds or less, and a half-value width of (10-12) diffraction determined through X-ray rocking curve analysis is 200 seconds or less
Data Source
AI summary
Provided is a technology capable of improving the quality of a GaN layer that is formed on an underlying substrate. A group III-nitride laminated substrate includes an underlying substrate, a first layer that is formed on the underlying substrate and is made of aluminum nitride, and a second layer that is formed on the first layer and is made of gallium nitride. The second layer has a thickness of 10 μm or less. A half-value width of (0002) diffraction determined through X-ray rocking curve analysis is 100 seconds or less, and a half-value width of (10-12) diffraction determined through X-ray rocking curve analysis is 200 seconds or less.