200V, 4MV/cm lateral diamond MOSFET

We report here the fabrication and characterization of a lateral monocrystalline diamond Metal Oxide Semiconductor Field Effect Transistor (MOSFET). First, 20–40 nm of an Al
2
O
3
layer has been deposited by ALD (380°C) on Oxygen terminated boron doped diamond and annealed at high temperature (500°C). This process has been optimized to build MOS capacitors that show gate control with distinctive accumulation, flatband, depletion and deep depletion, regions without gate leakage. Following this, lateral diamond MOSFETs operating in the deep depletion regime have been experimentally demonstrated, exhibiting already impressive features: 200 V breakdown with 0.6 nA/mm gate and drain leakage, 4 MV/cm peak electric field at breakdown even without the use of field plates, carrier mobility between 1000 and 1700 cm
²
/V.s, with a doping of the epilayer at 1.75×10
¹⁷
cm
⁻³
(Boron doped-MPCVD).