Impact ionization and high-field transport in semiconductors
Bude, Jeffrey Devin
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/22805
Description
Title
Impact ionization and high-field transport in semiconductors
Author(s)
Bude, Jeffrey Devin
Issue Date
1992
Doctoral Committee Chair(s)
Hess, Karl
Department of Study
Electrical and Computer Engineering
Discipline
Electrical and Computer Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Electronics and Electrical
Language
eng
Abstract
Aspects of high field transport related to hot electron reliability effects are investigated--with special emphasis, the phenomenon of impact ionization. Both the ionization rate itself and its effect on bulk semiconductor transport are computed by a full-band Monte Carlo algorithm for Si and several III-V materials. Furthermore, a new interpretation of hot carrier luminescence spectra is given which can explain important features of hot electron distribution functions in MOSFETs.
Our theory of impact ionization in semiconductors expands an earlier theory of Kane and includes the effects of high electric fields and high scattering rates on the electron-electron collision process. It is shown that their combined effect, i.e., the intracollisional field effect and collision broadening, leads to a softening of the threshold energy for impact ionization and a marked increase in the anisotropy of the ionization rate with respect to the direction of the electric field. Ionization rates are presented for Si, GaAs, InP, InAs, and Ga$\sb{0.43}$In$\sb{0.57}$As. Using these ionization rates, several prejudices concerning impact ionization are re-examined and a new view of the role of thresholds is offered. Trends of ionization coefficients related to the energy band structure for these compounds are also discussed.
Finally, a new computational model for the physical mechanisms of light emission in Si under various doping and carrier densities is developed with incorporates various hot carrier distribution function models. Our model includes a realistic band structure which is essential to the study of hot carrier luminescence in Si. Furthermore, by including these band structure effects, it is shown that the dominant light emission mechanism in normally biased Si MOSFETs is a combination of direct and phonon-assisted inter-conduction band radiation.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
