GaAs MESFET device dependences on ion-implant tilt and rotation angles

Lightly Cr-doped liquid-encapsulated Czochralski (LEC) GaAs wafers were implanted with 5*10/sup 12/ 100-keV Si/sup 29/ ions/cm/sup 2/ at tilt angles between 0 and 13 degrees and at rotation angles between 0 and 45 degrees C. Capacitance-voltage measurements were then made to determine electron profiles. It was found that cross-wafer device uniformity can be improved using implant tilt angles greater than 9 degrees . For microwave MESFET devices, the maximum transconductances at low I/sub DS/ are achieved using tilt angles greater than 6 degrees and rotation angles greater than 30 degrees .<
>