Stress effect in Au-Si Schottky diode doped with Cu

Abstract

The stress effect in Au-Si Schottky diodes doped with copper was examined by photoelectric measurement under localized anisotropic stress of the order of 109 dyn/cm2. It was found out that the current increase with stress was due to the changes of both the shunt resistance and the effective Richardson constant of a Schottky diode. The changes of these diode parameters with stress are attributed to the multiplication of the residual lattice strain in silicon due to copper introduction. The lattice strain produces a strain-induced level at 0.160 eV from the conduction band edge. We can infer that a tunneling current component through the potential barrier via this strain-induced level increases with stress. To obtain a highly stress-sensitive diode, the lattice strain of the order of 0.9–1.2×10−4 must be introduced previously into the surface of silicon by the choice of a proper copper diffusion condition.