Title :
High frequency GaAs/Al0.25Ga0.75As heterojunction bipolar transistors with transparent indium-tin-oxide emitter contacts
Author :
Li, W.Q. ; Karakucuk, M. ; Kulman, J. ; East, J.R. ; Haddad, G.I. ; Bhattacharya, P.K.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Abstract :
The authors have characterised a GaAs/Al0.25Ga0.75As heterojunction bipolar transistor (HBT) with transparent indium tin oxide (ITO) emitter contacts. An ITO to n-GaAs contact resistance of 2*10-7 Omega /cm2 was measured with 50AA of indium as a prelayer. HBT devices with fT=18GHZ, fmax=20GHz, and optical pulse response of 80ps FWHM have been measured. The results indicate that this device technology is a good candidate for application in optically controlled microwave circuits.
Keywords :
III-V semiconductors; aluminium compounds; contact resistance; gallium arsenide; heterojunction bipolar transistors; indium compounds; ohmic contacts; phototransistors; solid-state microwave devices; tin compounds; 18 GHz; 20 GHz; GaAs-Al 0.25Ga 0.75As; GaAs/Al 0.25Ga 0.75As heterojunction bipolar transistors; HBT devices; ITO-GaAs; InSnO-GaAs; contact resistance; current gain; ohmic contact; optical pulse response; optically controlled microwave circuits; photoresponse; phototransistor; power gain; transparent ITO emitter contacts;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19931493
