Etude du comportement electrique des semiconducteurs multicristallins à base de silicium – effet des joints de grains

Abstract

This thesis deals with two principle axes : • Statistical characterization • And dynamical characterization of pn and Schottky (Al/mc-Si) diodes. Statistical characterization is done through experimental ܫሺܸሻ and ܥሺܸሻ measures using Polix-Photowatt multicristalline silicon structures. Parameters taken into account were the Aluminium plot position, the metal nature and the operating temperature. We used an iterative ܫሺܸሻ method and we developed a ܥሺܸሻ method to extract diode parameters. Results obtained indicated the presence of trap levels in the grain boundaries, an important effect of the metal position and operating temperature. Dynamical characterization is carried out by the ac-small signal measurements applied to Shottky and ݊݌diodes. These structures identification showed a fractional behavior of the ݊݌diode and an integer behavior of the Schottky one. The main contributions of this work were then: • The electrical characterization of multicrystalline silicon through Schottky Al/mc-Si diodes; • Development of an iterative method based on ܥሺܸሻ measurements to extract active doping densities; • Proposition of an electrical equivalent circuit to explain polycrystalline silicon electrical behavior; • Proposition of an identification diode method based on ac-small signal measurements; • Experimental demonstration that ݊݌diode is a fractional system and Schottky diode is an integer one.