Fracture of GaAs Wafers

Abstract

Fracture characteristics of undoped and several kinds of doped GaAs single-crystal wafer were studied. The fracture toughness value determined by four-point bending fracture test of specimens precracked by indentation at room temperature showed no difference for In-, Si-, Cr- and undoped crystals. Indentation microcracking characteristics of In-, Si- and undoped crystals and probability distribution functions of the fracture stresses of In-doped and undoped crystals were found not to have meaningful differences. The polarity of the indentation cracking in relation to the indentation rosette extension and the temperature dependence of the fracture toughness value in relation to the crack tip plasticity were also investigated.