Growth of strained Si and strained Ge heterostructures on relaxed Si1−xGex by ultrahigh vacuum chemical vapor deposition

Abstract

Numerous applications require the growth of planar strained-layer heterostructures on relaxed Si1−xGex. After briefly reviewing these applications as well as the challenges in growing such heterostructures, we provide experimental examples illustrating the influence of lattice mismatch, growth temperature, and film composition on the morphology of thin strained layers in the Ge–Si alloy system. Procedures for growing strained Si and strained Ge single and double heterostructures via ultrahigh vacuum chemical vapor deposition are described in detail. We demonstrate planar growth of strained Ge layers with lattice mismatches as high as 2%, planar Si layers on any Si1−xGex lattice constant, and double heterostructures that are comprised of a strained Ge layer capped with strained Si. Notably, the techniques described here have already been applied to the fabrication of extremely high mobility p- and n-channel metal–oxide–semiconductor field-effect transistors and germanium-on-insulator substrates.

SiGe high-temperature growth kinetics in reduced pressure-chemical vapor deposition

“…Bandgap engineering by controlling either the strain or the Ge content significantly improves the performances of Si-based devices such as modulation-doped field effect transistors (MODFETs) [1,2] or metal oxide semiconductor FETs (MOSFETs) [3][4][5]. The lattice mismatch inherent to the Si/SiGe system (4.2% for pure Ge) leads to the presence of threading dislocations and surface undulations for thick SiGe films grown on Si (0 0 1).…”

“…The aim being, in the very near future, to grow high-quality SiGe virtual substrates with final Ge concentrations between 20% and 50%, which are most interesting as templates for high electron [3] and hole mobility [4] tensile-strained Si channels or high hole mobility compressively strained Ge channels [5], we report in this paper on a systematic study in RP-CVD of the high-temperature (750 1CpTp950 1C) growth kinetics of SiGe using a SiH 2 Cl 2 +GeH 4 (+HCl) gaseous chemistry.…”

Asymmetrical quantum dot growth on tensile and compressive-strained ZnO nanowire surfaces

“…With increasing strain, the impact of the strain type on the QD energy becomes more apparent [32]. The compressive strain lowers the step energy while the tensile strain increases the step energy [33][34][35][36]. This will lead to the energy barrier, E 0 b , for compressive strained surface being larger than that for the tensile strained surface, E 00 b .…”

Promoting strain relaxation of Si0.72Ge0.28 film on Si (100) substrate by inserting a low-temperature Ge islands layer in UHVCVD

“…Thin, high quality low and high-Ge content SiGe buffers were successfully fabricated [5,14]. However, there are few reports by ultrahigh vacuum chemical vapor deposition (UHVCVD) due to the problem in growing at such low temperature (usually at 400 8C, sometimes even below 200 8C) [15].…”