Estudo de dispositivos eletrônicos baseados em filmes de diamante dopados com boro

Abstract

In this work, the main objective was the study of boron doped diamond films aiming the use of them as semiconductor material for electronic devices. Schottky diodes and a field effect transistor were the devices built with these films. We have determined the main transport properties (resistivity and carrier density) that revealed the semiconductor behavior of doped boron synthetic diamond films (p-type). We also have studied the influence of cleaning processes on the surface quality of diamond for the production of good metal-diamond electrical contacts. We have observed the increase in resistivity as well as a reduction of the surface conductivity that is associated to the removal of hydrogen terminated diamond layers in the ionic cleaning process. The changes promoted by cleaning were studied current-voltage and capacitance-voltage measurements. The analysis of the temperature dependent resistivity indicated the hopping mechanism as the dominant conduction process over a wide temperature range. In addition, we investigated the presence of deep energy levels of impurities or defects in the diamond lattice using capacitance spectroscopy. Finally, after well established the contacts properties on the diamond surface we fabricated and analyzed the characteristics of a prototype field effect transistors based on boron doped diamond with oxygen termination.