Composite Substrate Heat-Dissipation Channels for GaN Devices
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Solution Overview
Problem
The low thermal conductivity and poor heat dissipation performance of silicon-based substrates used for gallium nitride-based semiconductor devices lead to reduced performance and lifespan, particularly in high-power applications, and existing methods to enhance heat dissipation, such as substrate thinning and encapsulation optimization, are inefficient and prone to warping.
Innovation Solution
A composite substrate with a first semiconductor layer and a second semiconductor layer stacked, featuring heat dissipation grooves and channels that are interconnected to improve heat dissipation, potentially including a bonding layer and passivation structure, and optionally incorporating a circulating coolant to enhance thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If silicon or sapphire substrates are used to reduce epitaxy cost, then manufacturing cost is reduced, but heat dissipation capability deteriorates
Solution Approach 1:
The patent uses a composite substrate structure combining silicon substrate with silicon carbide layer, integrating the low cost and CMOS compatibility of silicon with the high thermal conductivity of silicon carbide to simultaneously achieve cost reduction and improved heat dissipation
Solution Approach 2:
The substrate is segmented into multiple functional layers (silicon substrate, silicon carbide layer, buffer layer, GaN layer) with distinct roles, allowing optimization of each layer's properties for both cost-effectiveness and thermal management
2Temperature
If substrate is thinned to improve heat dissipation capability, then heat dissipation performance is improved, but substrate hardness is reduced and warping occurs
Solution Approach 1:
Heat dissipation channels are locally introduced into the substrate rather than thinning the entire substrate, allowing heat dissipation enhancement in specific regions while maintaining the overall structural integrity and hardness of the substrate
Solution Approach 2:
Instead of addressing heat dissipation in the vertical dimension by thinning, the patent introduces horizontal heat dissipation channels within the substrate plane, transferring heat laterally to heat dissipation structures without compromising substrate thickness and strength
3Temperature
If encapsulation is optimized to improve heat dissipation, then heat dissipation capability is improved, but process complexity increases and production efficiency is reduced
Solution Approach 1:
Heat dissipation channels are pre-formed in the substrate before epitaxial growth and device fabrication, establishing the heat dissipation pathway in advance to avoid complex post-processing encapsulation modifications
Solution Approach 2:
The silicon carbide layer acts as an intermediary between the GaN device layer and the silicon substrate, providing a thermal management interface that simplifies the overall heat dissipation design compared to complex encapsulation solutions
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 composite substrate effectively addresses the heat dissipation challenge by creating an interconnected heat dissipation flow channel, improving the thermal management of high-power gallium nitride-based components, increasing their lifespan and production efficiency while maintaining structural integrity.
Implementation Method 1
a heat dissipation channel is disposed on a side wall of the first semiconductor layer, or a surface, away from the second semiconductor layer, of the first semiconductor layer, and the heat dissipation channel is in communication with the heat dissipation groove
Data Source
AI summary
Disclosed are a composite substrate and a semiconductor structure, and the composite substrate includes a first semiconductor layer and a second semiconductor layer that are stacked, at least one heat dissipation groove is disposed on a surface, close to the second semiconductor layer, of the first semiconductor layer, a heat dissipation channel is disposed on a side wall of the first semiconductor layer, or a surface, away from the second semiconductor layer, of the first semiconductor layer, and the heat dissipation channel is in communication with the heat dissipation groove. The composite substrate and the semiconductor structure according to the present application can effectively resolve a heat dissipation problem of a high-power gallium nitride-based component by using a heat dissipation channel and a heat dissipation groove that are interconnected internal and external.