The formation of elevated barrier height Schottky diodes to InP and In 0.53 Ga 0.47 AS using thin, excimer laser deposited Cd interlayers

Much recent attention has been paid to elevating the barrier height of contacts to InP and In0.53Ga0. 47As 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 (∼200A) 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 In0.53Ga0. 47As, re-spectively. The photodeposition process has been integrated with conventional clean room processing resulting in Au/Cd/In0.53Ga0. 47As 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 (∼10A thick) Cd-InP reaction zone covered by metallic Cd.