Gallium Nitride Process
Understanding GaN Process
GaN has revolutionized RF power amplifier technology. Its wide bandgap (3.4 eV vs 1.43 for GaAs) enables high breakdown voltage and high power density, while its high electron mobility provides high-frequency operation.
GaN Process Variants
| Process | Power Density | Thermal | Cost |
|---|---|---|---|
| GaN-on-SiC (150nm) | 5-8 W/mm | Excellent | High |
| GaN-on-SiC (100nm) | 3-5 W/mm, higher freq | Excellent | High |
| GaN-on-Si (200mm) | 3-5 W/mm | Good | Low |
| GaN-on-Diamond | 10+ W/mm | Best | Very High |
Frequently Asked Questions
What makes GaN superior for RF power?
Wide bandgap enables high breakdown voltage (5-10x GaAs power density). High electron mobility enables high frequency. High thermal conductivity (SiC substrate) enables heat removal. 28-50V operation simplifies matching.
GaN-on-SiC vs GaN-on-Si?
SiC: 3.5x better thermal conductivity than Si. Preferred for military, high power (>100W), and high reliability. Si: larger wafers (200mm vs 100-150mm), lower cost, adequate for moderate power (5G base station PAs at 10-50W).
What frequency can GaN operate?
0.15um GaN: DC to 20 GHz. 0.1um GaN: DC to 40 GHz. 0.05um GaN: approaching 100 GHz. GaN is replacing GaAs for PAs up to Ka-band and extending into W-band with advanced processes.