High-Photocurrent and Wide-Bandwidth UTC Photodiodes With Dipole-Doped Structure
Meng, Qian Qian
Liu, Chong Yang
Ang, Kian Siong
Manoj Kumar, Chandra Mohan
Date of Issue2014-07-25
School of Electrical and Electronic Engineering
InP-based unitraveling-carrier photodiodes (UTC-PDs) with novel dipole-doped structure to achieve high photocurrent as well as wide bandwidth are demonstrated in this letter. The dipole-doped layers in combination with a 22-nm-thick undoped InGaAs setback layer were employed at the InGaAs/InP absorption and collection interface to reduce the current blocking effect. A high photocurrent of 160 mA with 1.9 GHz 3-dB bandwidth from a 70-(mu ) m-diameter top-illuminated UTC-PD is achieved. A large 3-dB bandwidth of 62.5 GHz, extracted using an equivalent circuit model, has also been obtained from a 12-(mu ) m-diameter UTC-PD device. The results demonstrate that the dipole-doping can serve as an effective alternative to the quaternary InGaAsP layer at InGaAs/InP interface for InP-based UTC-PD to suppress the current blocking and reduce the complexity in epilayers growth and device fabrication.
Dipole-doped layer; high speed; photocurrent; uni-traveling-carrier photodiodes (UTC-PDs); 3-dB bandwidth
IEEE Photonics Technology Letters
© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The published version is available at: [http://dx.doi.org/10.1109/LPT.2014.2343260].