Group III Nitride Substrate With Young’s Modulus Control for Low Warping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Group-III element nitride substrates obtained through heteroepitaxial growth are prone to warping, which affects the uniformity and performance of devices such as light-emitting diodes and semiconductor lasers.
Innovation Solution
A Group-III element nitride substrate with controlled Young's modulus fluctuation in the thickness direction, achieved by adjusting the growth speed of the nitride crystal and removing the base substrate, resulting in a freestanding substrate with reduced warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If heteroepitaxial growth is used to produce Group-III element nitride substrate, then the substrate can be obtained on a base substrate, but warping is liable to occur
Solution Approach 1:
The patent applies parameter changes by controlling the fluctuation width of Young's modulus in the thickness direction to be 50% or less. This involves adjusting growth conditions during heteroepitaxial growth to achieve uniform mechanical properties through the substrate thickness, thereby suppressing warping while maintaining ease of manufacture
Solution Approach 2:
The patent implements preliminary action by pre-controlling the Young's modulus distribution during the heteroepitaxial growth process itself. By managing the fluctuation width of Young's modulus from the beginning of substrate production, the warping issue is prevented before it occurs, rather than correcting it afterward
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 substrate exhibits minimal warping, ensuring uniformity and improved performance of functional layers, enhancing the production of large-sized devices.
Implementation Method 1
The Group-III element nitride substrate may be obtained by, for example, as described in Patent Literature 1, adopting, as a base substrate, a substrate including a material different in composition such as a sapphire substrate, and heteroepitaxially growing a Group-III element nitride crystal on the base substrate
Data Source
AI summary
A Group-III element nitride substrate includes a first main surface and a second main surface facing each other, wherein a fluctuation width of a Young's modulus in a thickness direction of the Group-III element nitride substrate is 50% or less.