Epitaxial n/sup +/ layer GaAs mesa-finger interdigital surface photodetectors

Author

Darling, Robert B. ; Nabet, Bahram ; Samaras, John E. ; Ray, Sankar ; Carter, Even L.

Author_Institution

Dept. of Electr. Eng., Washington Univ., Seattle, WA, USA

Volume

10

Issue

10

fYear

1989

Firstpage

461

Lastpage

463

Abstract

Several varieties of interdigital surface photodetectors have been fabricated on semi-insulating GaAs using mesa-etched n/sup +/ epitaxial layers as the carrier collection electrodes. This structure provides a significant responsivity improvement over conventional metal-semiconductor-metal (MSM) photodiodes by eliminating the surface reflection of the metal fingers and by providing increased photoconductive gain. High-speed testing using 100-ps doubled Nd:YAG pulses gave FWHM (full width at half maximum) responses of less than 500 ps for a 4- mu m finger width and spacing and showed minimal degradation from standard MSM detectors of the same surface geometry. By introducing no additional process steps, the mesa-finger detectors are also monolithically compatible with mesa-etched GaAs MESFET technology.<>

Keywords

III-V semiconductors; Schottky gate field effect transistors; gallium arsenide; photodetectors; phototransistors; semiconductor epitaxial layers; 5 micron; FWHM; GaAs; MESFET technology; YAG:Nd; YAl5O12:Nd; carrier collection electrodes; interdigital surface photodetectors; mesa-etched n/sup +/ epitaxial layers; photoconductive gain; responsivity improvement; surface geometry; Detectors; Electrodes; Epitaxial layers; Fingers; Gallium arsenide; Photoconducting materials; Photodetectors; Photodiodes; Reflection; Testing;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.43100

Filename

43100