The innovation engine for new materials

Taishi Kato

Taishi Kato


University of California Santa Barbara


Electrical and Computer Engineering

Site Abroad: 

Micro/Nanoelectronics, Tyndall National Institute, Cork


Maryam Shayesteh

Faculty Sponsor(s): 

Ray Duffy

Project Title: 

Modeling advanced Germanium devices

Project Description: 

Silicon's robust qualities have made it the semiconductor of choice but as device scaling becomes increasingly more difficult alternative semiconductor materials are being researched. Germanium is viewed as a possible candidate to replace silicon in MOS devices due to its high electron (3900 cm/ V·s) and hole (1900 cm/ V·s) mobilities. In the case of silicon simulations, modelling and processing techniques are well established and are easily accessible but this is not the case for germanium. Modelling is a crucial tool in device research, processing devices for every experimental option is costly and time consuming compared to a modelling program which can run simulations quickly and provide valuable insight into experimental results without actually having to buy materials. Modelling programs also offer knowledge of the physics that takes place within the device in addition to optimizing the entire production of such components. This project sought to alter an existing silicon modelling program to accurately simulate germanium structures; the programs used were Silvaco’s ATLAS and ATHENA. This modification was done by using an existing modelling program created for silicon and manually manipulating the default parameters to match germanium’s mobility and recombination parameters. After implementing the correct parameters to fit a germanium model a resistor, diode and MOSFET were modelled in the program. The characteristics such as current densities, junction depth, dopant concentration, and electric field of simulated germanium devices were compared with expected results and with silicon devices offering further understanding of the behaviour of germanium based devices.