Effects of heat treatment on noise spectrum in Au-InP Schottky barriers

Measurements are reported on low frequency noise in Au-InP Schottky diodes after heating cycles. An 1/f noise component was dominant in annealing time range before 80 min. Observation of G-R noise spectra are achieved for long-term operations. Noise measurements between 77 K and 300 K have given the time constants and the activation energies of five trapping levels. The G-R processes are attributed to traps due to gold contamination in the depletion region.     

Interdiffusion effects of heat treatment on GaxIn1-xSb diodes metallised with gold

A thick gold deposition has been used for metallic contact to GaxIn1-xSb. On a diode arrangement, the interdiffusion of these elements has been studied with heat treatment at 200°C. Only Ga and In diffuse out of the initial interface into the gold top layer, where they form stable compounds. The depth distribution profiles show that the microalloying takes the form of a layered structure of fixed intermetallic phases.     

Parametric generated high-efficiency oscillations in acoustoelectric oscillators

Diagnostic experiments are presented indicating that the r-? emission of acoustoelectric oscillators includes important range of components due to parametric interactions. The process of conversion is characterised by the emission of a transitory frequency spectrum.     

Bias dependence of low-frequency gate current noise in GaAs MESFETs

The spectra of gate current noise are investigated in GaAs MESFETs between 10/sup 2/ and 10/sup 4/ Hz. A change in the white-noise behaviour is observed with the increase of the gate current. It is shown that the contribution of an ideal Schottky shot noise is associated with two thermal noise components. The thermal noise sources originate in different leakage conductances.<>     

1/f noise in MODFETs at low drain bias

The 1/f noise in normally-on MODFETs biased at low drain voltages is investigated. The experimentally observed relative noise in the drain current S_I/I² versus the effective gate voltage V_G=V_GS-V_off shows three regions which are explained. The observed dependencies are S_I/I²∝V_G ^m with the exponents m=-1, -3, 0 with increasing values of V_G. The model explains m =-1 as the region where the resistance and the 1/f noise stem from the 2-D electron gas under the gate electrode; the region with m=0 at large V_G or V_GS≅0 is due to the dominant contribution of the series resistance. In the region at intermediate V_G , m=-3, the 1/f noise stems from the channel under the gate electrode, and the drain-source resistance is already dominated by the series resistance