Nitrogen and phosphorus implanted MESFETs in semi-insulating 4H-SiC

Abstract Nitrogen and phosphorus ion implantation were used to fabricate 2 μm gate length, n-channel Metal-Semiconductor Field-Effect-Transistors (MESFETs) in semi-insulating bulk 4H-SiC. In order to create the channel region, either nitrogen or phosphorus ion-implantations was performed to a depth of 300 nm at room temperature to a volumetric concentration of 5×10 17 cm −3 . The source/drain regions were created by nitrogen implantation to a volumetric concentration of 2×10 19 cm −3 , regardless of the species used for the channel implantation. Annealing for a duration of 15 min at 1450 °C (for nitrogen-implanted channels) or 1500 °C (for phosphorus-implanted channels) activated the implants. This study utilized aluminum Schottky gates for the FETs. Both the nitrogen and phosphorus-implanted channel MESFETS exhibited pinch-off voltages at approximately 18 V and the drain saturation currents between 30 and 40 mA.