The fabrication is reported of large-area (73 μm in diameter) front-illuminated planar InGaAs PIN photodiodes on S-doped InP substrates through the prebake process and investigations are made of various Zn diffusion times on a 2.9-μm thick absorption layer. As a result of the best tuning of the Zn diffusion time, the large-area planar InGaAs PIN photodiodes achieve a lowest capacitance of 0.43 pF, a lowest dark current of 39 pA, a highest responsivity of 0.99 A/W (79% quantum efficiency) at λ = 1.55 μm, and a highest 3-dB bandwidth of 6.98 GHz for a bare chip and 4.53 GHz for the device packaged in a TO can, respectively. Furthermore, the developed PIN photodiodes possess high breakdown voltage (less than -25V) and provide the P and N electrodes located at different sides of the photodiodes, thus improving the devices for easy bonding and packaging.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering