PhD student position in numerical simulation of semiconductor devices

Information about the research
Transistors made in gallium nitride (GaN) on silicon carbide (SiC) substrate have proven to be good candidates for generating power at microwave frequencies. The high breakdown field of GaN combined with the high thermal conductivity of SiC are the main reasons for the great performance of these components. Compared to more traditional semiconductors such as silicon and gallium arsenide the GaN-based transistors offer a theoretical improvement on the order of one magnitude in terms of output power performance.

At the Microwave Electronics Laboratory we are developing III-Nitride-based High Electron Mobility Transistors (HEMTs) for application in microwave power generation and sensing. Methods for integrating passive devices (resistors, capacitors and inductors) have been developed for monolithically integrated wide bandgap semiconductor circuits (WBG-MMIC). We have just started work on realizing indium nitride (InN) based HEMTs aimed for applications at THz frequencies. InN is very promising at these high frequencies since it has the highest electron mobility and saturation velocity of all III-Nitride semiconductors.

Drift-Diffusion simulators, solving Poisson's equation together with the current continuity equations for electrons and holes, have provided insight into the operation principles of many semiconductor technologies. However, the combination of new materials, high electrical power, and high frequencies at our laboratory sets great challenges on these kind of simulations. Approaching THz frequencies the device size needs to be shrunk to the limit where quantum effects may not be neglected, and microscopic input from band-structure calculations should be added. Furthermore, the wavelength at THz frequencies approaches the physical dimensions of the device, implying the solution of Maxwell´s equations. 

Major responsibilities
As PhD student, you will work with numerical simulations of III-Nitride-based semiconductor devices, especially HEMTs for microwave power generation and sensing. You should also perform electrical measurements to verify simulated results. The majority of the working time will be dedicated to research within your project and to courses required for obtaining the PhD. You will cooperate with other researchers working on material growth and analysis, semiconductor processing, as well as microwave circuit design and characterization. You will also participate in teaching activities at Chalmers.

Position summary
Full-time temporary employment. The position is limited to a maximum of five years.

Qualifications
We are looking for a highly motivated and independent candidate with a Master of Science degree in Electrical Engineering, Engineering Physics, or Physics, preferably with knowledge in solid state physics and microwave electronics.

Experience in characterization and modeling of high frequency power devices is a plus. Good communicative and collaborative skills are required; the applicant is also expected to be proficient in both verbal and written English. 

Chalmers continuously strives to be an attractive employer. Equality and diversity are substantial foundations in all activities at Chalmers.

Application procedure
The application should be marked with Ref 20150259 and written in English. The application should be sent electronically via Chalmers webpage.


Application deadline: August 31, 2015

For questions, please contact:
Assoc. Prof. Hans Hjelmgren,
hans.hjelmgren@chalmers.se,
+46 31 7721737

Dr. Niklas Rorsman,
niklas.rorsman@chalmers.se,
+46 31 7725053

Prof. Herbert Zirath,
herbert.zirath@chalmers.se,
+46 31 7721852

*** Chalmers declines to consider all offers of further announcement publishing or other types of support for the recruiting process in connection with this position. *** 
   



Chalmers University of Technology conducts research and education in engineering sciences, architecture, technology-related mathematical sciences, natural and nautical sciences, working in close collaboration with industry and society. The strategy for scientific excellence focuses on our eight Areas of Advance; Built Environment, Energy, Information & Communication Technology, Life Science, Materials Science, Nanoscience & Nanotechnology, Production and Transport. The aim is to make an active contribution to a sustainable future using the basic sciences as a foundation and innovation and entrepreneurship as the central driving forces. Chalmers has around 11,000 students and 3,000 employees. New knowledge and improved technology have characterised Chalmers since its foundation in 1829, completely in accordance with the will of William Chalmers and his motto: Avancez!