AlGaN/GaN Schottky Barrier UV Photodetectors With a GaN Sandwich Layer

Author

Lee, K.H. ; Chang, P.C. ; Chang, S.J. ; Wang, Y.C. ; Yu, C.L. ; Wu, S.L.

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

9

Issue

7

fYear

2009

fDate

7/1/2009 12:00:00 AM

Firstpage

814

Lastpage

819

Abstract

We present the characteristics of an AlGaN/GaN Schottky barrier ultraviolet (UV) photodetectors (PDs) with and without a GaN sandwich layer. The effect of inserting this secondary GaN buffer layer on the growth mode and crystal properties of the whole epitaxial GaN layer was reported. It was found that we could reduce defect density and thus improve crystal quality of the AlGaN/GaN Schottky barrier UV PDs by using a GaN sandwich layer. It was also found that we could use the GaN sandwich structure to suppress photoconductive gain (PCG), enhance UV-to-visible rejection ratio (UTV-RR), reduce noise level, and enhance the detectivity of the fabricated PDs.

Keywords

III-V semiconductors; Schottky barriers; aluminium compounds; buffer layers; gallium compounds; photoconductivity; photodetectors; sandwich structures; semiconductor device noise; semiconductor epitaxial layers; semiconductor growth; ultraviolet detectors; AlGaN-GaN; Schottky barrier UV photodetector characteristics; UTV-RR; UV-to-visible rejection ratio; crystal properties; crystal quality; defect density reduction; epitaxial layer; gallium nitride sandwich layer; noise level reduction; photoconductive gain suppression; secondary buffer layer; Aluminum gallium nitride; Buffer layers; Gallium nitride; HEMTs; MODFETs; Photodetectors; Radiation detectors; Schottky barriers; Semiconductor radiation detectors; Substrates; Sandwich layer; secondary GaN buffer; ultraviolet (UV);

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2009.2022565

Filename

5170195