GaAs vertical PIN diode using MeV implantation

For high-power microwave switching, PIN diodes are preferred over MESFETs due to their higher breakdown voltage, lower on-state resistance, and lower off-state capacitance. The authors have fabricated vertical PIN diodes using MeV Si/S coimplantation and keV Be/P coimplantation into undoped semi-insulating GaAs to obtain buried n⁺ and surface p⁺ regions respectively. An exploratory device with a 500*500 mu m² junction area and a 3 mu m thick intrinsic region has a breakdown voltage of 70 V, reverse leakage current density of 40 mu A/cm² at 20 V, an off-state capacitance of 3.9 nF/cm² and a DC forward resistance of 2.4 Omega at 100 mA.