Structural and morphological characterization of InGaAs/InP 2.5 μm photodetector heterostructures with different metamorphic buffer layer profiles

doi:10.18721/JPM.183.234

Structural and morphological characterization of InGaAs/InP 2.5 μm photodetector heterostructures with different metamorphic buffer layer profiles

Physical electronics

Authors:

Barantsev O.V. Vasilkova E.I. Pirogov E.V. Dementev P.A. Nevedomskiy V.N. Karachinsky L.Ya. Novikov I.I. Sobolev M.S.

Abstract:

In_0.83Ga_0.17As/InP PIN-photodiode heterostructures with different metamorphic buffer layers' profiles have been grown by molecular beam epitaxy. Cross-section transmission electron microscopy images have been investigated to estimate the density of threading dislocations. Heterostructures' surface and its roughness have been researched by atomic force microscopy. The lowest dislocation density and surface roughness were observed in the heterostructure with a linear-graded metamorphic buffer layers (MBLs). MBLs were designed with a In mole fraction gradient of 0.18 rel. units/μm. Epitaxial growth was concluded with a final in situ high-temperature annealing step. Potential distribution of the heterostructures' cleaved surface has been researched by Kelvin probe force microscopy.