The Effects of Low Energy Ion-Beam Milling on the Physical and Electrical Properties of N-GaAs.

Low energy neutral Ar ion-beam etching of n-GaAs was investigated as a possible “cleaning” procedure prior to contact metallization. The ion-beam source energy was varied between 35 eV and 1200 eV at a fixed current density of 1 mA/cm 2 . The effects of ion-milling on lightly doped n-GaAs were analyzed electrically by measuring current-voltage (IV) and capacitance-voltage (CV) characteristics of Schottky barriers formed after the ion-milling. The metal semiconductor barriers were prepared immediately following ion-milling without breaking vacuum. Photoluminescence and Rutherford Backscattering (RBS) were used to determine if any physical modification of the surface and near surface region of the ion-milled substrates had occurred.