RF Terminology » RF Components » Microwave Semiconductor Materials: Si, GaAs, InP, GaN, AlN, InN Comparison
Microwave Semiconductor Materials: Si, GaAs, InP, GaN, AlN, InN Comparison
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This article provides a comparative overview of key properties for various semiconductor materials commonly used in microwave applications, specifically: Silicon (Si), Gallium Arsenide (GaAs), Indium Phosphide (InP), Gallium Nitride (GaN), Aluminum Nitride (AlN), and Indium Nitride (InN). The tabular format allows for easy comparison of these materials.
The following table summarizes the important microwave semiconductor material properties for these binary III-nitride compounds, measured at a temperature of 300K.
| Material Properties | GaAs | Si | InP | GaN | AlN | InN |
|---|---|---|---|---|---|---|
| Structure | Zinc Blende | Diamond Cubic | Zinc Blende | Wurtzite | Wurtzite | Wurtzite |
| Lattice constant | 5.653 | 5.431 | 5.869 | a=3.18, c=5.18 | a=3.11, c=4.97 | a=3.54, c=5.71 |
| Band Gap (eV) | 1.42 | 1.12 | 1.35 | 3.44 | 6.2 | 0.7 to 1.0 |
| Nature of bandgap | direct | indirect | direct | direct | direct | direct |
| Refractive index | 3.3 | 3.42 | 3.1 | 2.3 | 2.1 to 2.2 | 2.9 to 3.0 |
| Dielectric constant | 12.9 | 11.7 | 12.6 | 10.4 | 8.5 | 15.3 |
| Thermal conductivity (W/cm-L) | 0.46 | 1.56 | 0.68 | 2.0 to 2.4 | 3.0 to 3.3 | 0.6 to 1.0 |
| Electron Mobility (cm²/V-s) | 8000 | 1400 | 5400 | 2000 | 300 | 3200 |
| Hole Mobility (cm²/V-s) | 400 | 500 | 200 | 400 | 14 | - |
| Electron saturated velocity (10�?� cm/s) | 0.7 | 2.3 | 3.9 | 2.5 | 1.9 | 3.4 |
Key Takeaways:
- GaAs: Excellent electron mobility makes it suitable for high-frequency, low-noise amplifiers.
- Si: Cost-effective and widely used, though its indirect bandgap limits high-frequency performance compared to GaAs. It’s thermal conductivity is good.
- InP: High electron saturated velocity makes it good for high speed applications.
- GaN: High breakdown voltage and high thermal conductivity make it ideal for high-power amplifiers.
- AlN: Large band gap and high thermal conductivity make it good for high-temperature applications.
- InN: High electron mobility and saturated velocity make it suitable for high-frequency devices.
