Hardness and fracture toughness of semiconducting materials studied by indentation and erosion techniques

Abstract In recent years, the growing field of semiconductor micromechanics has created an increasing demand for strength data on semiconductors and for adequate tests and evaluations of their mechanical properties. In a recently published paper, the present authors have demonstrated that the solid particle erosion rate can be taken as a simple and highly reproducible statistical measure of the susceptibility of silicon and GaAs to contact damage in the micron range. In the present work the scope is broadened to include several new crystal orientations (and one new doping level), as well as three other materials: germanium, InP and InAs, for which the hardness and fracture toughness K Ic values are determined by means of the indentation technique. K Ic values are also derived from erosion data by means of a recently reported brittle fracture model, based on non-lateral spalling in single-crystal semiconductors. These values are compared with results obtained by the indentation technique and conventional test methods reported in the literature. Fracture surface energies are deduced from the experimental K Ic results. The materials tested are ranked with respect to elastic properties, microhardnesses, fracture toughnesses, and sensitivities to contact damages in general. The influence of crystallographic orientation on room temperature microfracture properties is clearly established, but the corresponding influence on microhardness is found to be rather limited. The influence of doping on the room temperature mechanical properties is noticeable but small.