GaN-based avalanche photodiodes

Author

Verghese, S. ; McIntosh, K.A. ; Molnar, R.J. ; Chen, C.-L. ; Molvar, K.M. ; Melngailis, I. ; Aggarwal, R.L.

Author_Institution

Lincoln Lab., MIT, Lexington, MA, USA

fYear

1998

fDate

22-24 June 1998

Firstpage

54

Lastpage

55

Abstract

Visible-blind UV sensors for applications that require both wide bandwidth and high sensitivity will benefit from avalanche photodiodes (APDs) that have an internal gain mechanism. This paper reports the first clear observation of avalanche multiplication gain in an ultraviolet photodiode fabricated in the III-V materials system. The photodiodes were fabricated from GaN layers grown on a sapphire substrate by hydride vapour phase epitaxy (HVPE) (Molnar et al., J. Crystal Growth, vol. 178, 147, 1997). First, a 10 /spl mu/m thick layer of n-type GaN was deposited, followed by a 0.25 /spl mu/m thick Zn-doped "i" layer. Circular mesas of 30 /spl mu/m diameter were formed by reactive ion etching and were contacted with a semitransparent Ti film.

Keywords

III-V semiconductors; avalanche photodiodes; gallium compounds; semiconductor device metallisation; semiconductor device testing; sputter etching; transparency; ultraviolet detectors; vapour phase epitaxial growth; 0.25 micron; 10 micron; 30 micron; APDs; Al/sub 2/O/sub 3/; GaN layers; GaN-based avalanche photodiodes; III-V materials system; Ti-GaN:Zn-GaN-Al/sub 2/O/sub 3/; Zn-doped i-layer; avalanche multiplication gain; avalanche photodiodes; circular mesas; hydride vapour phase epitaxy; internal gain mechanism; n-type GaN layer; photodiodes; reactive ion etching; sapphire substrate; semitransparent Ti film contact; sensitivity; sensor bandwidth; ultraviolet photodiode; visible-blind UV sensors; Avalanche photodiodes;

fLanguage

English

Publisher

ieee

Conference_Titel

Device Research Conference Digest, 1998. 56th Annual

Conference_Location

Charlottesville, VA, USA

Print_ISBN

0-7803-4995-4

Type

conf

DOI

10.1109/DRC.1998.731118

Filename

731118