Effective dark current suppression with asymmetric MSM photodetectors in Group IV semiconductors

Author

Chui, Chi On ; Okyay, Ali K. ; Saraswat, Krishna C.

Author_Institution

Dept. of Electr. Eng., Stanford Univ., CA, USA

Volume

15

Issue

11

fYear

2003

Firstpage

1585

Lastpage

1587

Abstract

We have demonstrated for the first time, with both simulations and experiments, the application of an asymmetric metal electrode scheme in Group IV metal-semiconductor-metal photodetectors (MSM-PDs) to effectively lower dark current (I/sub dark/) without sacrificing the photocurrent (I/sub photo/) substantially. A new metric was introduced by normalizing the photocurrent-to-dark current ratio to the input optical power (NPDR) to provide an objective assessment of the detector performance. Improvement of at least 1.4 times in NPDR was obtained with asymmetric MSM-PDs. Finally, the impact of MSM sizing on NPDR was also addressed.

Keywords

Schottky barriers; dark conductivity; elemental semiconductors; germanium; infrared detectors; metal-semiconductor-metal structures; photodetectors; silicon; Ge; Ge-based materials; Group IV metal-semiconductor-metal photodetectors; Group IV semiconductors; MSM sizing; NPDR; Ni; Schottky barrier heights; Si; Ti; asymmetric MSM photodetectors; asymmetric metal electrode; effective dark current suppression; input optical power; near-infrared photodetection; normalizing photocurrent-to-dark current ratio; Circuits; Dark current; Detectors; Electrodes; Optical attenuators; Optical interconnections; Optical receivers; Photodetectors; Photonic band gap; Schottky barriers;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2003.818683

Filename

1237596