Device Simulation

Advanced Monte Carlo Modeling of
III-V Field-Effect Transistors

Device Simulation

Supervisor Assoc.Prof.Dr. Cengiz BESIKCI, Master study of Aydin T.BAKIR, January 1999

Related studies: Numeric Schrodinger Solution.

Device Animation Downloads

Advanced particle level simulation of the MESFET and MODFET devices are shown in the animations. General information about the simulation is given in this web page.

MESFET AVI

MODFET AVI

MESFET and MODFET simulation AVI files are in ZIP format to reduce download time. You should uncompress these files to see the animations.

List of International Journal Papers

C.Besikci, A. T. Bakir and B. Tanatar," Dielectric Screening Effects on Electron Transport in GaInP/InGaAs/GaAs Quantum Wells," Journal of Applied Physics, vol. 88, pp. 1504-1511, 2000.

List of medical information technology related journal papers and symposiums

Hacettepe Üniversitesi Hastaneleri’ndeki Bilgi Sistemlerinin Birlikte Çalışabilirliği P.YILDIRIM, A.BAKIR Tıp Bilişimi 06, 3. Ulusal Tıp Bilişimi Kongresi, Antalya, Turkiye 16-19 Kasım 2006, Sayfa 103-109

Interoperability between various IT Systems in Hacettepe University Hospitals in Turkey P.YILDIRIM, A.BAKIR International HL7 Interoperability Conference IHIC 2006, Cologne Germany ,24-25 August 2006, http://ihic.hl7.de/proceedings.html

Web Based Teleradiology Application in Hacettepe University Hospitals in Turkey P.YILDIRIM, A.BAKIR, S.BİRİNCİ In Proceedings of 12th International Symposium for Health Information Management Research Sheffield, UK 18 to 20 July 2007, Page 109-118

Hacettepe Üniversitesi Hastaneleri’nde Web Temelli Teleradyoloji Uygulaması, P.YILDIRIM, A.BAKIR, S.BİRİNCİ 4. Ulusal Tıp Bilişimi Kongresi, 15-18 Kasım 2007 Antalya, Türkiye

A workflow based nuclear medicine information system. (nmis) integrated into his and pacs. O. Ugur. 1. , F. Sahin. 2. , N. B. Kesimli. 2. , D. Duzgunoglu 2., A. Bakir 2. , S. Birinci 2. , V.Babekoglu 3., H. Bilginer 4. European Journal of Nuclear Medicine and Molecular Imaging, Journal Issue : Volume 33, Supplement 2 / September, 2006

Thesis Abstract

Semiconductor device modeling and simulation techniques have an important role in today’s microelectronics technology. These techniques allow the designers examine the operation of novel devices and circuits before fabrication and check their design ideas. In this study, an improved ensemble Monte Carlo simulation program has been developed for the Modulation Doped Field-Effect Transistors (MODFETs) by including the effects of screening on polar optical phonon scattering. Three valleys of the GaAs conduction band, size quantization in the valley and the lowest three subbands in the quantum well have been taken into account. The higher lying states have been considered to have three dimensional properties. We have also taken real space transfer into account. The Monte Carlo program is descibed in detail and the simulation results are presented. The result show that screening effects, which are generally ignored in the Monte Carlo simulations of MODFETs, should be included in the simulation in order to predict the device performance correctly. Screening significantly changes the band populations throughout the device by lowering the intra-subband polar optical phonon scattering rates. It has also been observed that ignorence of these effects is expected to result in an underestimation of the cut-off frequency of a MODFET with a reasonably high two-dimensional electron gas density.

Keywords: Device Modeling, Monte Carlo, Screening, polar optical phonon scattering, MODFET, MESFET.

MESFET Monte Carlo Modeling

The GaAs MESFET structure used in the simulations is shown in the Figure. The device has dimensions of 2m x 0.2m. The gate length is chosen to be 1m. GaAs doping density is taken to be Nd=1.0E17 cm-3.

MODFET Monte Carlo Modeling

The AlGaAs layer thickness is 70 nm and this layer has a doping density of 5.0E17 cm-3. The GaAs layer thickness is 110 nm and has a doping density of 1.0e14 cm-3. n+ regions have the doping density of 5.0xE17 cm-3.