Anti-phase domain suppression and increased electron mobilities in InSb epilayers and quantum wells on off-axis Ge(211) and GeOI(001) substrates*

We report on the molecular beam epitaxy of InSb epilayers and Si \textit{$\delta $}-doped InSb/Al$_{x}$In$_{1-x}$Sb quantum wells (QWs) on off-axis Ge(211) and Ge-On-Insulator (GeOI)-On-Si substrates. The high carrier mobilities in $n$-type InSb and $p$-type Ge QWs provide a motivation to integrate these structures on a single substrate for an improved CMOS technology. Growth on GeOI substrates may also make possible the integration of InSb infrared detectors with Si transistors. We evaluate the suppression of anti-phase domains (APDs) through analysis of Reflection High-Energy Electron Diffraction (RHEED) patterns obtained during growth on off-axis substrates. The narrowest X-ray rocking curve width is 100 arc sec for a 4.0-$\mu $m-thick InSb epilayer. The highest room temperature electron mobilities of a 4.0-$\mu $m-thick InSb epilayer and an InSb QW are 64,000 and 23,500 cm$^{2}$/V-s for growth on off-axis Ge(211) and GeOI(001) substrates, respectively. We attribute the single-domain RHEED patterns, reduced X-ray rocking curve widths, and increased electron mobilities to the suppression of APDs in the structures grown on off-axis Ge(211) and GeOI(001) substrates.