Lattice-Matched III-Nitride Composite Substrate Formation
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Solution Overview
Problem
Conventional methods for forming composite substrates with III-nitride seed layers often result in strain and defects due to the need for additional bonding steps and strain relief techniques, leading to poor crystalline quality and device performance in semiconductor light-emitting devices.
Innovation Solution
A method involving a growth substrate with a lattice constant closely matched to the III-nitride seed layer, allowing for single-step bonding and reduced strain, where the seed layer is grown with the nitrogen face exposed, eliminating the need for trenches and additional bonding steps, and enabling growth on the gallium face for improved crystalline quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional bonding steps and strain relief techniques are used to form composite substrates with III-nitride seed layers, then the substrate can be formed, but strain and defects are introduced leading to poor crystalline quality
Solution Approach 1:
The patent changes the lattice constant parameter of the growth substrate to closely match the III-nitride seed layer, reducing strain and eliminating the need for complex bonding steps and strain relief techniques while improving crystalline quality
Solution Approach 2:
The patent extracts and eliminates unnecessary processing steps including trenches and additional bonding operations, retaining only the essential single-step bonding process that achieves the desired composite substrate structure with improved crystalline quality
2Reliability
If additional bonding steps and trenches are used for strain relief, then strain is reduced, but processing complexity and contamination risk increase
Solution Approach 1:
By optimizing the lattice constant match between substrate and seed layer, the patent reduces strain at the source, eliminating the need for additional bonding steps and trenches that would introduce contamination opportunities
Solution Approach 2:
The patent removes intermediate bonding layers and trench structures that create interfaces susceptible to contamination, achieving a simpler, cleaner structure with improved device performance
3Ease of manufacture
If multiple bonding steps are used to form the composite substrate, then the substrate structure can be achieved, but processing time and complexity increase
Solution Approach 1:
The patent combines multiple separate bonding operations into a single-step bonding process by optimizing the initial substrate-seed layer interface, reducing processing time while maintaining structural integrity
Solution Approach 2:
The patent performs preliminary optimization of the substrate lattice constant before bonding, ensuring that the single-step bonding process succeeds without requiring subsequent corrective operations or additional bonding steps
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 reduces strain and contamination, resulting in better crystalline quality and performance of III-nitride light-emitting devices with less processing complexity and higher yield.
Implementation Method 1
a III-nitride layer is grown on a growth substrate
Implementation Method 2
The growth substrate has an in-plane lattice constant asubstrate. The III-nitride layer has a bulk lattice constant alayer. In some embodiments, [(|asubstrate−alayer|)/asubstrate]*100% is no more than 1%
Data Source
AI summary
In a method according to embodiments of the invention, a III-nitride layer is grown on a growth substrate. The III-nitride layer is connected to a host substrate. The growth substrate is removed. The growth substrate is a non-III-nitride material. The growth substrate has an in-plane lattice constant asubstrate. The III-nitride layer has a bulk lattice constant alayer. In some embodiments, [(|asubstrate−alayer|)/asubstrate]*100% is no more than 1%.