Contributions for the modelling of the semiconductor devices based on heterodimensional Schottky Contacts

Author(s)

Regiane Aparecida Ragi Pereira

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2003-02-21

Examining board members

Murilo Araujo Romero; Antonio Martins Figueiredo Neto; Jose Roberto Leite; Antonio Carlos Seabra; Jacobus Willibrordus Swart

• Advisor: Murilo Araujo Romero

Abstract

This thesis deals with the modeling of the electronic characteristics of semiconductor devices based on heterodimensional Schottky contacts, defined as contacts between a metal and a reduced dimensionality system. Specifically, this work focus on the situation in which a metal is placed in direct contact with a two dimensional electron gas located at the interface of a modulation doped heterojunction. Devices of interest are Schottky diodes as well as metal-semiconductor-metal (MSM) structures. For the capacitance-voltage characteristics a quasi two-dimensional model is developed, which yields very good agreement with available experimental results. For the current-voltage characteristics a unified model is presented, considering the tunneling as well as the thermionic emission mechanisms. Our theoretical predictions, supported by a few experimental findings, suggest that, for photodetection applications, the use of heterodimensional contacts, replacing conventional metal-semiconductor junctions, can reduce the dark current by at least one order of magnitude. (AU)