LASER-ANNEALED SILICON IMPATT DIODES

Laser annealing of double drift silicon IMPATT diodes was studied and found to be advantageous compared to conventional furnace processing techniques. Both pulsed and cw laser annealing of ion implanted drift regions and junctions gave improved rf (140 GHz) diode performance over that obtained from diodes fabricated by standard methods from the same starting material and implantation conditions. The improved performance of laser annealed diodes is attributed to an increase in crystal perfection in the regions damaged by ion implantation. Both dopant activation and carrier mobility are thereby improved; laser annealing also provides improved spatial definition of the diode junction and drift regions.