The Study Of Ge-based InAs/GaAs Quantum-dot Light-emitting Structure

Light,as an information transmission medium,has huge advantages such as fast transmission speed,large capacity,low lost and so on,comparing with traditional electrical communication,and until now brilliant achievements have been made in middle-distance and long-distance communication,and what’s more,optical fiber communication has become one of the pillars of the 21 st century communication technology.Except middle-distance and long-distance communication,more improvements can be made for optical communication development in ultra-short-distance like data base and super computer,and this is the reason why silicon photonics attracts widespread attention.To achieve optical interconnects on chip,realizing a high quality on-chip-laser is the bottleneck problem.As direct-gap semiconductor,Ⅲ-Ⅴ materials have high-efficiency light-emission,therefore Ⅲ-Ⅴ materials epitaxial growth on Si wafer is considered as the most promising choice.However it is great challenges to obtain high quality Ⅲ-Ⅴ material on Si wafer due to large lattice mismatch,anti-phase domain and thermal expanse coefficient mismatch.Compared with Si,Ge almost has the same lattice constant with Ga As;in addition the technique of Ge film growth on Si wafer is very mature.Therefore it is more feasible to achieve high quality Ⅲ-Ⅴ materials epitaxial growth on Si substrate by using Ge as an intermediate layer.In this paper,we revolve around Ga As epitaxial growth on Ge substrate and launch a series experimental work,and the main research results are obtained as following.1.We systematically study on the Ge homogeneous epitaxial growth,research the effect of de-oxidation surface on post Ge film growth,and we develop a “two-step” growth mode and significantly broaden the growth parameter window for atomic-scale flat Ge surface.2.We focus on the growth mode of Ga As on Ge wafer and compare the different effects of anti-phase domain self-annihilation on miscut substrate and diatomic steps,finally we achieve ultra-thin and high quality Ga As buffer on Ge substrate,by high temperature annealing to realize high density diatomic steps.3.On this basis,we achieve 1.3μm and 1.55μm wavelength emission quantum-dot structure monolithically growth on Ge substrate,and room-temperature photoluminescence spectra shows a high-efficiency light-emission In As/Ga As QD structure epitaxial growth on Ge substrate is obtained.