Radiation breakdown in silicon wafers

Radiation breakdown in silicon slabs is observed and studied as revealed in anomalous behavior of the dose characteristics of their radiation defects when the radiative intensity is varied. A theory is constructed for reversible radiation breakdown due to the bistability which develops in a gas of radiation vacancies when the gas can be regarded as quasi-two-dimensional. In order to explain the exponential saturation of the dose characteristics as the irradiation intensity is increased, scenarios are proposed in which different forms of the constituent radiation defects develop. Some parameters of the bistable gas of primary vacancies are estimated, including diffusion coefficients, dimensions of inhomogeneity regions, and the rate of movement of the stratification line. On the whole, satisfactory agreement with experiment is obtained. Discrepancies between the diffusion coefficient for neutral vacancies obtained here and in the literature are attributed to the role of interband recombination accompanying radiation defect formation during electron bombardment. Zh. éksp. Teor. Fiz. 114, 1067–1078 (September 1998)