Novel fabrication of Ti-Pt-Au/GaAs Schottky diodes

Author

Jean, Christopher A St ; Bishop, William L Bishop, Jr. ; Sarpong, Benjamin K. ; Marazita, Steven M. ; Crowe, Thomas W.

Author_Institution

Dept. of Electr. Eng., Virginia Univ., Charlottesville, VA, USA

Volume

47

Issue

7

fYear

2000

fDate

7/1/2000 12:00:00 AM

Firstpage

1465

Lastpage

1468

Abstract

A novel fabrication process for evaporated refractory-metal/n-GaAs Schottky contacts is presented. This process avoids the use of photoresist lift-off in order to maintain an exceptionally clean Schottky interface. Resulting millimeter-wave varactor diodes exhibit the same anode quality as previous electroplated platinum/n-GaAs varactor diodes but with improved reliability, repeatability and cost. A titanium deposition-rate of 1.2-1.6 nm/s was found to yield minimum ideality factor and breakdown voltages equivalent to those of Pt devices at a doping density of 1×10¹⁷ cm^-3. Devices fabricated on material doped at 2.3×10¹⁷ cm^-3 and above, however, had significantly lower breakdown voltages compared to platinum diodes. This is believed to be due to the lower barrier height of the titanium anodes, which causes an increased tunneling current

Keywords

III-V semiconductors; Schottky diodes; gallium arsenide; gold; millimetre wave diodes; platinum; semiconductor device reliability; semiconductor-metal boundaries; titanium; varactors; MM-wave varactor diodes; Schottky interface; Ti anodes; Ti deposition rate; Ti-Pt-Au-GaAs; Ti/Pt/Au/GaAs Schottky diodes; barrier height; breakdown voltages; evaporated refractory-metal/n-GaAs Schottky contacts; fabrication; minimum ideality factor; reliability; tunneling current; Anodes; Fabrication; Gallium arsenide; Maintenance; Platinum; Resists; Schottky barriers; Schottky diodes; Titanium; Varactors;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.848293

Filename

848293