Change in Surface Conductivity of Elastically Deformed p-Si Crystals Irradiated by X-Rays

Abstract

Changes in conductivity of irradiated and non-irradiated p-Si mono-crystals under the influence of elastic uniaxial mechanical stress were investigated in this paper. An analytical expression was suggested to describe the dependence of surface conductivity as a function of mechanical stress and X-ray irradiation dose. It was shown that 4-angular nano-particles on the surface of “solar” silicon affect the electroconductivity changes under mechanical stress. It was established that X-ray irradiation causes the generation of point defects in silicon. These defects suppress the dislocations movement. It was shown that the resistivity of previously irradiated samples of “electronic” silicon is only slightly sensitive to the influence of uniaxial compression at certain deformation rate.

Mechanically Stimulated Changes in Surface Electrical Conductivity of X-Irradiated Silicon Crystals

“…In the area of the near-surface crystal layer where the Al film is deposited, due to the discrepancy between the parameters of the Al and Si lattices, a region of the crystal stress state is formed under the aluminum film. Under the action of the strain potential due to the discrepancy between the parameters of the Al and Si lattices, the value of electrical conductivity in the near -surface layer of the crystal increases and, as a rule, by 50-70% the mobility of charge carriers increases [13,[15][16]. In addition, the metal film deposited on the Si surface contributes to the formation of a site in the near-surface layer, which is an effective getter for deep-level structural defects [9,13].…”

“…Under the action of the strain potential due to the discrepancy between the parameters of the Al and Si lattices, the value of electrical conductivity in the near -surface layer of the crystal increases and, as a rule, by 50-70% the mobility of charge carriers increases [13,[15][16]. In addition, the metal film deposited on the Si surface contributes to the formation of a site in the near-surface layer, which is an effective getter for deep-level structural defects [9,13]. Such defects can be impurity atoms moved from the sample volume to the near-surface region, Si atoms that leave the lattice nodes at interstitial positions, and vacancies generated at such outputs [11].…”

“…The exposure dose was 492 R/min. The absorbed dose was increasing by 130 Gy in every 30 minutes [13]. Mechano-stimulated change in electrical conductivity R(σ) the test samples were performed using the setup described in [13,14].…”