DocumentCode :
1074974
Title :
Influence of impact ionization on the drain conductance in InAs-AlSb quantum well heterostructure field-effect transistors
Author :
Brar, Berinder ; Kroemer, Herbert
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
Volume :
16
Issue :
12
fYear :
1995
Firstpage :
548
Lastpage :
550
Abstract :
Using an InAs-AlSb heterostructure field-effect transistor (HFT) structure modified to incorporate an epitaxial p-type GaSb back gate, we measure the impact ionization current caused by hot electrons in the InAs channel. We show that the impact ionization current is only a small fraction of the deleterious increase in the drain current commonly observed in InAs-based transistors. Most of the drain current rise is caused by a feedback mechanism in which holes escaping into the substrate act like a positively charged parasitic back gate leading to an increase in the electron current flow in the channel by an amount that is large compared to the impact ionization current itself. Removal of the impact-generated holes by the epitaxial back gate breaks the feedback loop, and dramatically improves the DC characteristics of the devices, and increases the range of usable drain voltages.
Keywords :
III-V semiconductors; aluminium compounds; field effect transistors; hot carriers; impact ionisation; indium compounds; semiconductor quantum wells; DC characteristics improvement; InAs channel; InAs-AlSb; drain conductance; drain current; electron current flow; epitaxial p-type GaSb back gate; feedback mechanism; heterostructure field-effect transistors; hot electrons; impact ionization current; impact-generated holes removal; parasitic back gate; quantum well HFET; quantum well heterostructure FET; Charge carrier processes; Current measurement; Electrons; Feedback; HEMTs; Impact ionization; MODFETs; Space charge; Substrates; Voltage;
fLanguage :
English
Journal_Title :
Electron Device Letters, IEEE
Publisher :
ieee
ISSN :
0741-3106
Type :
jour
DOI :
10.1109/55.475583
Filename :
475583
Link To Document :
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