Revolutionary 3D Architecture for >1kV Power Devices
Breaking the voltage barrier with vertical gallium nitride technology. By driving current through thick GaN drift layers instead of laterally across the surface, vertical GaN FETs achieve SiC-class voltage handling while maintaining GaN's superior switching speed—the future of high-voltage power conversion.
Gallium-nitride (GaN) devices leverage a heterojunction between AlGaN and GaN that creates a two-dimensional electron gas (2-DEG) with exceptional mobility. This electron sheet forms spontaneously at the interface due to polarization effects, enabling both normally-on (depletion-mode) and normally-off (enhancement-mode) device architectures.
| Parameter | Lateral GaN (E-mode) | Vertical GaN |
|---|---|---|
| Breakdown Capability | 600–900 V typical | 1,200 V today; roadmap to 3 kV |
| Current Density | Limited by surface field crowding | Much higher (area scales like SiC) |
| Thermal Path | Top-side only | Heat sinks through GaN substrate – better cooling |
| Wafer Cost | Low (GaN-on-Si) | High — requires bulk GaN or engineered substrates |
| Target Applications | Consumer electronics, data centers | EV drivetrains, utility-scale converters, grid infrastructure |
Vertical current conduction through thick drift layers eliminates surface field crowding, enabling higher breakdown voltages and current densities.
Heat dissipation through the GaN substrate provides efficient cooling paths, reducing junction temperatures and improving reliability.
Advanced edge termination and field plate designs optimize electric field distribution, pushing breakdown limits beyond traditional lateral devices.
Bulk GaN and engineered substrate technologies enable low-defect-density vertical structures with superior performance metrics.
Maintains GaN's inherent high electron mobility for MHz switching frequencies while handling kV-class voltages.
Robust avalanche characteristics provide inherent protection against voltage transients and improve system reliability.
Explore band diagrams, 2-DEG formation, and carrier dynamics in vertical GaN structures with interactive parameter control.
Compare lateral vs. vertical GaN performance metrics including Ron, switching losses, and thermal characteristics.
Visualize heat flow patterns and junction temperature distributions in vertical GaN power devices.
Analyze electric field profiles and breakdown mechanisms in vertical GaN structures with edge termination.
Test vertical GaN devices in power converter topologies for EV and grid applications.
Comprehensive technical details on vertical GaN technology, fabrication processes, and design considerations.
import numpy as np
from scipy import constants as const
class VerticalGaNFET:
"""
Physics-based model for vertical GaN power FET
"""
def __init__(self, device_params):
# Material parameters
self.Eg = 3.4 # eV, GaN bandgap
self.Nc = 2.3e18 # cm^-3, conduction band density
self.epsilon_r = 9.0 # GaN relative permittivity
self.mu_n = 1500 # cm^2/V-s, electron mobility
# Device dimensions
self.drift_thickness = device_params['drift_thickness'] # um
self.drift_doping = device_params['drift_doping'] # cm^-3
self.active_area = device_params['active_area'] # cm^2
def calculate_breakdown_voltage(self):
"""
Calculate theoretical breakdown voltage using critical field
"""
Ec = 3.3e6 # V/cm, critical field for GaN
# Punch-through design
Vbr = 0.5 * Ec * self.drift_thickness * 1e-4
return Vbr
def calculate_specific_resistance(self):
"""
Calculate specific on-resistance (mΩ-cm²)
"""
q = const.e
rho = 1 / (q * self.drift_doping * self.mu_n)
R_drift = rho * self.drift_thickness * 1e-4
R_specific = R_drift * self.active_area * 1000 # mΩ-cm²
return R_specific
def figure_of_merit(self):
"""
Baliga's Figure of Merit (BFOM)
"""
epsilon_0 = const.epsilon_0 * 1e2 # F/cm
Vbr = self.calculate_breakdown_voltage()
Ron_sp = self.calculate_specific_resistance() * 1e-3 # Ω-cm²
BFOM = (epsilon_0 * self.epsilon_r * self.mu_n * (3.3e6)**2) / Ron_sp
return BFOM
# Example: 1.2kV vertical GaN device
device = VerticalGaNFET({
'drift_thickness': 10, # um
'drift_doping': 1e16, # cm^-3
'active_area': 0.01 # cm^2
})
print(f"Breakdown Voltage: {device.calculate_breakdown_voltage():.0f} V")
print(f"Specific Resistance: {device.calculate_specific_resistance():.2f} mΩ-cm²")
print(f"Baliga FOM: {device.figure_of_merit():.2e}")
Development of bulk GaN substrates and initial 600V prototypes
Demonstration of 1.2kV devices with competitive Ron and switching performance
First commercial products for EV inverters and industrial applications
Achievement of 3kV devices for grid-scale applications and MW converters
Vertical GaN enables smaller, lighter, and more efficient traction inverters for next-generation electric vehicles. The combination of high voltage capability and fast switching reduces system size by 40% while improving range through higher efficiency.
For renewable energy integration and HVDC transmission, vertical GaN offers unprecedented power density and efficiency. Multi-level converters using vertical GaN can achieve >99% efficiency at MW power levels.