Zinc diffusion process investigation of InP-based test structures for high-speed avalanche photodiode fabrication

The characterization of zinc diffusion processes for three different test s tructures has been investigated. The comparison between the different diffu sion process conditions for different test structures were explored. The zi nc diffusion profiles, such as the diffusion depth and the zinc dopant conc entration, were examined using secondary ion mass spectrometry with varying the amount of Zn3P2 source, the ampoule volume, and the diffusion time. It is observed that the diffusion profiles are severely impacted on the proce ss parameters, such as the amount of Zn3P2 source, the ampoule volume, and the diffusion time, as well as material parameters, such as doping concentr ation of the diffusion layer. These results from the Zn diffusion process c an be utilized for the high-speed InP/InGaAs avalanche photodiodes fabricat ion. (C) 2000 Elsevier Science Ltd. All rights reserved.