Reduction of threading dislocation density in Ge/Si using a heavily As-doped Ge seed layer

TitleReduction of threading dislocation density in Ge/Si using a heavily As-doped Ge seed layer
Publication TypeJournal Article
Year of Publication2016
AuthorsLee, KHong, Bao, S, Wang, B, Wang, C, Yoon, SFatt, Michel, J, Fitzgerald, EA, Tan, CSeng
JournalAip Advances
Volume6
Issue2
Pagination025028
Date Published2016/02//
ISBN Number2158-3226
Keywordschemical-vapor-deposition, detector, germanium epitaxial film, growth, motion, Pressure, si, silicon 001
Abstract

High quality germanium (Ge) epitaxial film is grown directly on silicon (001) substrate with 6. off-cut using a heavily arsenic (As) doped Ge seed layer. The growth steps consists of (i) growth of a heavily As-doped Ge seed layer at low temperature (LT, at 400 degrees C), (ii) Ge growth with As gradually reduced to zero at high temperature (HT, at 650 degrees C), (iii) pure Ge growth at HT. This is followed by thermal cyclic annealing in hydrogen at temperature ranging from 600 to 850 degrees C. Analytical characterization have shown that the Ge epitaxial film with a thickness of similar to 1.5 mu m experiences thermally induced tensile strain of 0.20% with a treading dislocation density (TDD) of mid 10(6)/cm(2) which is one order of magnitude lower than the control group without As doping and surface roughness of 0.37 nm. The reduction in TDD is due to the enhancement in velocity of dislocations in an As-doped Ge film. (C) 2016 Author(s).

Short TitleAIP Adv.