Alexandria Digital Research Library

Transport Properties of III-N Hot Electron Transistors

Author:
Suntrup, Donald J.
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
Mark Sherwin and Umesh Mishra
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2015
Issued Date:
2015
Topics:
Electrical engineering and Condensed matter physics
Keywords:
Nitride
Hot electron transistor
GaN
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2015
Description:

Unipolar hot electron transistors (HETs) represent a tantalizing alternative to established bipolar transistor technologies. During device operation electrons are injected over a large emitter barrier into the base where they travel along the device axis with very high velocity. Upon arrival at the collector barrier, high-energy electrons pass over the barrier and contribute to collector current while low-energy electrons are quantum mechanically reflected back into the base. Designing the base with thickness equal to or less than the hot electron mean free path serves to minimize scattering events and thus enable quasi-ballistic operation. Large current gain is achieved by increasing the ratio of transmitted to reflected electrons. Although III-N HETs have undergone substantial development in recent years, there remain ample opportunities to improve key device metrics. In order to engineer improved device performance, a deeper understanding of the operative transport physics is needed. Fortunately, the HET provides fertile ground for studying several prominent electron transport phenomena. In this thesis we present results from several studies that use the III-N HET as both emitter and analyzer of hot electron momentum states. The first provides a measurement of the hot electron mean free path and the momentum relaxation rate in GaN; the second relies on a new technique called electron injection spectroscopy to investigate the effects of barrier height inhomogeneity in the emitter. To supplement our analysis we develop a comprehensive theory of coherent electron transport that allows us to model the transfer characteristics of complex heterojunctions. Such a model provides a theoretical touchstone with which to compare our experimental results. While these studies are of potential interest in their own right, we interpret the results with an eye toward improving next-generation device performance.

Physical Description:
1 online resource (167 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3v987k6
ISBN:
9781339471693
Catalog System Number:
990046180220203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Donald Suntrup III
File Description
Access: Public access
SuntrupIII_ucsb_0035D_12792.pdf pdf (Portable Document Format)