Current oscillations in high-resistivity silicon with deep levels

Abstract

Investigations of current oscillations observed in high resistivity Au‐compensated n+–i–in+ and p+–p+ silicon samples are reported. The specific resistivities of the i regions are 20 k Ω cm and about 105 Ωcm at the n‐type Si and 14 k Ωcm at the p‐type silicon, respectively. The dc I–U‐characteristics and the contact preparation justify the assumption that single injection SCLC are attributable to the current oscillations and that double injection is negligible. The waveforms of the oscillations are not sinusoidal in general. The frequencies are in the range of 100 kHz at the 105 Ωcm material. In the 20 k Ω cm samples a pulse like waveform is typical for the current instabilities and the repetition rate of the pulses is about 10 kHz. Measurements using voltage pulses show that current oscillations are initiated a certain delay time after applying the voltage pulse, if a critical trap occupation is reached.

Properties of the gold acceptor state in silicon

“…Using a 50 pm thick Au/Sb (0.5%) foil to alloy the n+ contacts, an n+ layer of about 12 pm [21] exists with the saturation concentration of Sb. In this n+ layer the hole lifetime is about 10-lo s [24] and the diffusion length L, N 0.1 pm .…”