Planar InP/InGaAs Avalanche Photodiodes Grown By Atmospheric Pressure Metal Organic Vapour Phase Epitaxy.

We compare the performance of high speed planar InP/InGaAs separate absorption, grading and multiplication region avalanche photodiodes where the grading layer consists of a single quaternary layer or a chirped superlattice. The devices are grown by atmospheric pressure metal organic vapour phase epitaxy which has been found to produce good quality, low defect density, uniform material on large area (2") slices. Both types of grading layer are found to suppress the slow component of the avalanche photodiodes pulse response while exhibiting low dark currents (1-10nA @ 0.9Vb). The characteristics of the diodes are shown to be uniform over 2" wafers and suitable for use at bit rates up to at least 2.4Gbaud.