Effects of fabrication and temperature on baritt diode oscillators

Abstract

The large signal analysis considers the current transport as a thermionic injection-diffusion process, to obtain the shape of injected current, induced external current, power output and efficiency. This analysis is simple and flexible and is later utilized with a modification to explain the observed performance of the diffused BARITT diode as a function of the temperature.

Diffused device performance is evaluated from 350°K to 77°K. The power output and efficiency improve as the temperature decreases from 350°K to 150°K due to decreased space-charge effects. At 77°K the performance deteriorates due to the current transport being almost completely controlled by space-charge limited current. Schottky device performance is evaluated from 374°K to 300°K, and is mainly controlled by the current-voltage relationship, which is dependent on concentration of holes at the valence band edge and the space-charge effects.

Two processes are developed for the fabrication of Schottky and diffused BARITT diodes. Au-Cr metallization is used to obtain Schottky contact and metallization of the diffused contact. The Au-Cr-NSi Schottky barrier height varies from .81 to .59 eV as the chromium thickness increases from zero (no chromium) to more than 200 Two processes are developed for the fabrication of Schottky and diffused BARITT diodes. Au-Cr metallization is used to obtain Schottky contact and metallization of the diffused contact. The Au-Cr-NSi Schottky barrier height varies from .81 to .59 eV as the chromium thickness increases from zero (no chromium) to more than 200 Å. This technique of achieving a control in barrier height by varying the intermediate metal thickness can also be utilized to advantage in other metal-semiconductor systems. This technique of achieving a control in barrier height by varying the intermediate metal thickness can also be utilized to advantage in other metal-semiconductor systems.

The purpose of this thesis is to obtain improved understanding of BARITT devices, by experimentally and theoretically investigating BARITT diode oscillators and related devices. To accomplish this objective, silicon Schottky and diffused BARITT and related devices are fabricated, the performance of these devices is evaluated and a large signal analysis is developed to explain observed performance as an oscillator.