Why Choose GaN High Electron Mobility Transistors (HEMTs)?
Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) are among the fastest and most efficient semiconductor devices available for high-frequency and high-power applications. Unlike conventional MOSFETs, HEMTs utilize a heterojunction formed between two semiconductor materials with different bandgaps—typically AlGaN and GaN. This creates a high-density two-dimensional electron gas (2DEG), enabling exceptional electron mobility, low on-resistance, and outstanding switching performance.
Because of their excellent electrical characteristics, GaN HEMT structures on sapphire are widely used in RF electronics, microwave circuits, radar systems, satellite communications, and next-generation wireless infrastructure.
Common Applications of GaN HEMTs
- 5G and wireless communication infrastructure
- RF power amplifiers
- Microwave and millimeter-wave electronics
- Satellite communications and receivers
- Radar and defense systems
- Power converters and switching devices
- Electric vehicle power electronics
- Aerospace and scientific instrumentation
UniversityWafer also supplies HEMT structures on alternative substrates, including Silicon Carbide (SiC) HEMTs and Silicon HEMTs, allowing researchers to select the substrate best suited to their thermal, electrical, and cost requirements.
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Typical AlGaN/GaN HEMT on Sapphire Specifications
| Parameter | Specification |
|---|---|
| Substrate | Sapphire |
| GaN Buffer Thickness | 1.8 ± 0.25 μm |
| AlGaN Composition | 20%, 23%, or 26% ± 1.25% Al |
| AlGaN Thickness | 21 ± 1 nm |
| AlN Interlayer Thickness | 1 ± 0.5 nm |
| Sheet Resistance | <420 Ω/sq |
| Electron Mobility | >1200 cm²/V·s |
| Sheet Carrier Concentration | >1 × 1013 cm-2 |
| Wafer Bow | <60 μm |
| Buffer Layer Resistivity | >1 × 105 Ω/sq |
| Substrate Resistivity | >10,000 Ω/sq |
| Surface Quality | >90% defect-free area |
Custom GaN HEMT structures are available with different wafer diameters, AlGaN compositions, epitaxial layer thicknesses, carrier concentrations, and mobility specifications for RF, microwave, and power semiconductor research.
GaN HEMT Structure on Sapphire
A GaN HEMT structure on sapphire is an AlGaN/GaN heterostructure grown on an insulating sapphire substrate. These wafers are used for high-frequency, high-power, and RF semiconductor device research, including microwave amplifiers, radar electronics, 5G communication systems, satellite receivers, and power switching devices.
How AlGaN/GaN HEMTs Work
HEMTs use a heterojunction between two semiconductor materials with different bandgaps. In an AlGaN/GaN HEMT, the interface between the AlGaN barrier layer and GaN channel forms a high-density two-dimensional electron gas, also known as a 2DEG. This electron channel provides high mobility and enables fast switching at high frequencies.
Why Use Sapphire for GaN HEMT Growth?
Sapphire substrates are commonly used for GaN epitaxial growth because they are electrically insulating, mechanically strong, chemically stable, and cost-effective compared with some alternative substrates.
- Excellent electrical insulation
- Strong mechanical stability
- Good chemical resistance
- Large-area wafer availability
- Lower cost than many bulk GaN or SiC options
- Suitable for GaN, AlGaN, and AlN epitaxial structures
Typical GaN HEMT Layer Structure
A GaN HEMT wafer on sapphire typically includes several epitaxial layers engineered to support high electron mobility and device reliability.
- Sapphire substrate: insulating base wafer for GaN epitaxy
- AlN nucleation layer: helps manage lattice mismatch and supports GaN growth
- GaN buffer layer: provides the main crystalline layer for device operation
- AlGaN barrier layer: creates the heterojunction needed for 2DEG formation
- GaN channel: supports high electron mobility
- Source, gate, and drain contacts: define the transistor structure
Applications of GaN HEMT Wafers
GaN HEMT structures on sapphire are used where high power density, high breakdown voltage, and high-frequency operation are required.
- RF power amplifiers
- Microwave electronics
- Radar transmitters
- Satellite communication systems
- 5G and wireless infrastructure
- Power conversion devices
- High-speed switching research
- Defense and aerospace electronics
- Wide-bandgap semiconductor research
Sapphire vs. SiC for GaN HEMTs
Sapphire is an excellent choice for research and cost-sensitive GaN HEMT development. However, silicon carbide (SiC) offers higher thermal conductivity, which can be beneficial for high-power devices where heat dissipation is critical. Many researchers compare GaN-on-sapphire, GaN-on-SiC, and GaN-on-silicon structures depending on the target RF, microwave, or power electronics application.
Request GaN HEMT on Sapphire Wafers
UniversityWafer supplies AlGaN/GaN HEMT structures on sapphire with custom layer thicknesses, AlGaN composition, sheet resistance, mobility, sheet carrier concentration, bow, and buffer resistivity. Provide your required wafer diameter, substrate, HEMT layer design, and quantity for a fast quote.