To establish the links between the electronic properties of bulk semiconductors and the electrical behaviour of p-n junctions, MOS structures, Schottky barriers and Ohmic contacts as basic building blocks of almost all semiconductor devices including diodes, bipolar and MOS transistors, photodiodes and lasers.
Now the electronic properties of semiconductors of different type when combined together or with metals and insulators result in the specific electrical behaviour and characteristics of the corresponding p-n junctions, MOS structures, Schottky barriers and Ohmic contacts.
The generic current-voltage (I-V) and capacitance-voltage (C-V) characteristics of p-n junctions, MOS structures, Schottky barriers and Ohmic contacts with a reference to the physical processes responsible for their specific behaviour. Appropriate mathematical equations describing the I-V and C-V characteristics of the above structures.
Use of appropriate mathematical equations to calculate the I-V and C-V characteristics of p-n junctions, MOS structures, Schottky barriers and Ohmic contacts.
Formation of p-n junctions; band structure, depletion layer, depletion width, junction field and build-in potential; forward and reverse bias conditions; reverse bias capacitance and breakdown; injection and forward bias current; current-voltage characteristics and the Schottky equation. Field effect in MOS capacitor; band structure in accumulation, depletion and inversion; C-V characteristics. Formation of Schottky barrier and current-voltage characteristics of a Schottky contact. The Ohmic contact is as a specific implementation of a Schottky contact. A heterojunction is an interface between two layers or regions of dissimilar semiconductors. These semiconducting materials have unequal band gaps as opposed to a homojunction. The GaN high-electron-mobility transistor (HEMT) structure generally consists of a low-temperature GaN nucleation layer, a thin unintentionally doped GaN buffer layer, a part undoped AlGaN barrier layer, and a thin undoped GaN cap layer.
The aim of the laboratory is to consolidate the knowledge and the understanding of the p-n junctions, MOS structure, heterojunction diode, GaN-based HEMT device, Schottky barriers and Ohmic contacts from the Second Part of the course using Technology Computer Aided Design (TCAD) simulations width the industry standard Synopsys TCAD tool Sentaurus. The Metal-Oxide-Silicon structure is the heart of the Metal Oxide Semiconductor Field Effect Transistor (MOSFET) which the basis of the CMOS technology that penetrates every aspect of human life. The Si-SiO2 MOS system has been studied extensively because it is the most important part of the MOSFET. To understand the formation of the MOSFET channel, and the transistor performance, you will experiment in the TCAD environment with the simulation and the analysis of MOS structure.
The objectives of the laboratory include: