Quantum-dot resonant-cavity separate absorption, charge, and multiplication avalanche photodiode operating at 1.06 μm

We report on the design, fabrication and performance of a quantum-dot (QD) resonant-cavity separate absorption, charge, and multiplication avalanche photodiode (APD). The device was grown on GaAs using molecular beam epitaxy and was designed to detect light near 1.06 μm. The absorbing region consists of a stack of five self-assembled QD layers, that were formed by the deposition of six monolayers of In/sub 0.5/Ga/sub 0.5/As, with GaAs spacer layers. The peak efficiency at 1.06 μm is 57% with a spectral bandwidth of 1.3 nm. The photodiode exhibits low dark current, low multiplication noise (k<0.3), good gain characteristics and a low-breakdown voltage (/spl sim/15 V), which is much lower than that of Si-based APD's operating at 1.06 μm.