Band Diagram Study of Different Epitaxies and Estimation of the Infuence on the Device Characteristics for Indium Phosphide and Gallium Nitride Based HEMTs
Project Description
The goal of this semester project is to gain intuition about band diagram engineering for two different kinds of material classes and practical limits which have to be considered when a HEMT is to be fabricated on them.
In a HEMT the foremost purpose of the epitaxial structure is to create a two-dimensional electron gas (2DEG) with a sheet carrier density nS and mobility of this carriers _ which should be as high as possible. Once this electron gas is created ohmic- (source and drain) and Schottky contacts (gate) are fabricated on the wafer. The success of the fabrication of this contacts is characterized by the ohmic contact resistance RC and reverse-bias leakage currents Ileak. Different epitaxies and choice of metallizations of source, drain and gate will facilitate or prevent the easy fabrication of one of these contact types.