Title :
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
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;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2003.818683
