The formation of elevated barrier height Schottky diodes to inp and In0.53Ga0.47as using thin,excimer laser-deposited Cd interlayers

Much recent attention has been paid to elevating the barrier height of contacts to InP and In_0.53Ga_{0. 47}As via the formation of a thin, intermediate layer between the semicon-ductor and a conventionally deposited, highly conductive contact layer. Here, we report on the use of thin (～200Å) excimer laser photodeposited Cd as an interlayer between these semiconductors and Au overlayers in order to raise the barrier height of the re-sulting diodes. Current-voltage measurements of ideal Schottky diodes fabricated using this process yield barrier heights of 0.70 eV and 0.55 eV to InP and In_0.53Ga_{0. 47}As, re-spectively. The photodeposition process has been integrated with conventional clean room processing resulting in Au/Cd/In_0.53Ga_{0. 47}As transistors with high transconductances (～200 mS/mm) and operating frequencies (f _max ～ 30 GHz). X-ray photoelectron spec-troscopy of thin Cd photodeposits on InP shows that the process produces an interfacial (～10Å thick) Cd-InP reaction zone covered by metallic Cd.