Numerical simulation of gamma-ray radiation dose-rate effects of typical semiconductor devices

In order to research radiation effects of ultra-small semiconductor device, a coupled algorithm for FVM with MC Method is described. The transient responses of reverse biased diodes with different structures, working at Gamma-ray radiation environment, are simulated by the new algorithm. The results are compared with Enlow's photocurrent model. It shows that the algorithm is reliable in simulating dose-rate effects of semiconductor devices. The relationship among dose-rate, thickness of epitaxial layer, pulse-width and reverse photocurrent is also investigated. It shows that epi-layer constrains the collecting volume, so that the thinner epi-layer is, the lower peak value and the fast falling-down speed of photocurrent will be; and that the narrower pulse-width is, the higher peak value of current with respect to the same dose will be. (authors)