Growth of high quality Ge-on-Si layer by using an ultra-thin LT-Si buffer in RPCVD

2nd International Workshop on Materials Science and Mechanical Engineering

机械制造;材料科学

Zhang, J.^1 ; Chen, X.^1 ; Wang, J.A.^1 ; Chen, G.B.^1 ; Tang, Z.H.^1 ; Tan, K.Z.^1 ; Cui, W.^1

Science and Technology on Analog Integrated Circuit Laboratory ChongQing, 400060, China^1

关键词: Band gap narrowing;    Chemical mechanical polishing(CMP);    Cyclic annealing;    Epitaxial layer thickness;    High-temperature annealing;    Low surface roughness;    Monolithic photonic integrated circuits;    Threading dislocation densities;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/504/1/012020/pdf
DOI  :  10.1088/1757-899X/504/1/012020

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Ge epitaxial layer on Si substrate becomes more attractive for Si-based monolithic photonic integrated circuit (PIC). Low threading dislocation density and low surface roughness play a vital role in realizing the fabrication of the Ge optoelectronic devices. In this study, an ultra-thin LT-Si buffer for the deposition of Ge layer was investigated with regard to Ge layer's crystallinity, symmetrical characteristic, threading dislocation density, and surface roughness. As a result, Ge epitaxial film has low threading dislocation density (TDD=5106cm-2) and smooth surface (RMS = 0.68nm) in 5μm5μm scan field with the Ge epitaxial layer thickness of about 1μm. What's more, it was grown in a short time by using an ultra-thin LT-Si buffer layer without using chemical mechanical polishing (CMP), high temperature annealing, H2 annealing or cyclic annealing. In addition, room temperature direct gap photoluminescence was observed from intrinsic tensile-strained (0.21%) Ge-on-Si layer and bandgap narrowing in Ge epitaxial layer is 85meV.