SiC Substrate AlGaN HEMT for Heat Dissipation and Breakdown Voltage
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Solution Overview
Problem
Current semiconductor devices, such as HEMTs with GaN and AlGaN layers, face challenges in improving characteristics like heat dissipation and breakdown voltage, and achieving high carrier density and low ON-resistance.
Innovation Solution
A semiconductor device structure is proposed, comprising a SiC first region, an Alx2Ga1-x2N second region, and an Alx3Ga1-x3N third region, with specific electrode configurations and insulating layers, where the second region is epitaxially grown on the first region and the third region is grown on the second region, optimizing lattice constants and stress conditions to enhance carrier concentration and reduce ON-resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional GaN-based HEMT structure is used, then device simplicity is maintained, but heat dissipation performance is insufficient and breakdown voltage is limited
Solution Approach 1:
The patent employs a composite material structure consisting of SiC substrate, AlGaN barrier layer, and GaN channel layer. This multi-material composition enables superior heat dissipation through SiC's high thermal conductivity while maintaining the desired electrical characteristics through the AlGaN/GaN heterostructure, thereby resolving the contradiction between heat dissipation performance and structural simplicity.
Solution Approach 2:
The patent applies local quality by using different materials with specific properties in different regions: SiC for heat dissipation in the substrate region, AlGaN for carrier confinement and polarization effect in the barrier layer, and GaN for high electron mobility in the channel. This localized optimization of material properties achieves enhanced heat dissipation without uniformly increasing overall device complexity.
2Strength
If AlGaN barrier layer with high Al composition is used, then breakdown voltage is improved, but carrier density decreases and ON-resistance increases
Solution Approach 1:
The patent optimizes the Al composition ratio x in AlxGa1-xN barrier layer within the range 0.2≤x≤1, and controls the barrier layer thickness to 2-100 nm. By precisely adjusting these parameters, the patent achieves a balance between breakdown voltage enhancement (through higher Al content) and maintaining low ON-resistance (through controlled thickness and composition), resolving the contradiction between these two performance metrics.
Solution Approach 2:
The patent applies partial action by using an AlGaN barrier layer with moderate Al composition (0.2≤x≤1) rather than maximum Al content, combined with optimized thickness (2-100 nm). This partial application of high-Al-content material achieves sufficient breakdown voltage improvement while avoiding excessive carrier density reduction, thereby maintaining low ON-resistance.
3Manufacturing precision
If lattice mismatch is reduced by material selection, then crystalline quality is improved, but stress control becomes more difficult
Solution Approach 1:
The patent controls the Al composition ratio x in AlxGa1-xN within 0.2≤x≤1 and adjusts the barrier layer thickness to 2-100 nm. By optimizing these parameters, the patent achieves a balance between reducing lattice mismatch (improving crystalline quality) and managing stress in the heterostructure, as the Al composition and thickness directly influence both lattice matching and stress distribution.
Solution Approach 2:
The patent applies local quality by carefully selecting material composition and thickness for each layer: SiC substrate for lattice matching, AlGaN barrier layer with specific Al content for stress management, and GaN channel for high quality crystalline growth. This localized optimization of each layer's properties achieves both good crystalline quality and stress control.
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 configuration results in improved heat dissipation, higher breakdown voltage, and increased carrier density, leading to lower ON-resistance and superior transistor performance compared to traditional GaN-based HEMTs.
Implementation Method 1
an Alx2Ga1-x2N second region, and an Alx3Ga1-x3N third region, with specific electrode configurations and insulating layers, where the second region is epitaxially grown on the first region and the third region is grown on the second region
Implementation Method 2
optimizing lattice constants and stress conditions to enhance carrier concentration and reduce ON-resistance
Data Source
AI summary
According to one embodiment, a semiconductor device includes first to third regions, and first to third electrodes. The first region includes a first partial region, a second partial region, and a third partial region between the first and second partial regions. A direction from the first partial region toward the first electrode is aligned with a first direction. A direction from the second partial region toward the second electrode is aligned with the first direction. A second direction from the first electrode toward the second electrode crosses the first direction. A direction from the third partial region toward the third electrode is aligned with the first direction. At least a portion of the third region is provided between the first and second electrodes in the second direction. At least a portion of the second region is provided between the third and first regions.