Ultra-micro-indentation of silicon and compound semiconductors with spherical indenters

Details of microindentation of silicon, such as the semiconductor-to-metal transformation, which takes place on loading, have been examined using sphe rical indenters. Various forms of silicon are studied, including heavily bo ron-doped wafers and silicon damaged and amorphized by ion implantation as well as material containing dislocations. Results indicate that only silico n, which contains high concentrations of point defects or is amorphous, exh ibits mechanical properties that differ significantly from undoped, defect- free crystal. Amorphous silicon exhibits plastic flow under low indentation pressures and does not appear to undergo phase transformation on loading a nd unloading. Indentation of compound semiconductors is also studied and th e load/unload behavior at room temperature is quite difficult ent from that of silicon. Both gallium arsenide and indium phosphide, for example, under go slip-induced plasticity above a critical load.