Different architectures of relaxed Si1−xGex/Si pseudo-substrates grown by low-pressure chemical vapor deposition: Structural and morphological characteristics

Band engineering and absorption spectra in compressively strained Ge0.92Sn0.08/Ge (001) double quantum well for infrared photodetection

“…The electronic band parameters, gaps, discontinuities and effective masses for heterointerfaces between compressively strained Ge 1−x Sn x and relaxed Ge have been computed at room temperature. From this preliminary and mendatory work, we conclude that pseudomorphic Ge 1-x Sn x alloys become direct band gap semiconductors at a Sn-fraction of 15 [19,20], Ge on insulator (GeOI) substrates formed by wafer bounding [21][22][23] or recent advances in the growth of germanium nanowire arrays by vapour-liquid-solid (VLS) and vapoursolid-solid (VSS) techniques [24]. In this work and on the basis of our previous results [25] on the electronic band parameters for GeSn strained, first we determined the band offsets at Ge 1−x Sn x /Ge strained (001)-oriented relaxed interfaces.…”

Low-defect metamorphic Si (Ge) epilayers on Si (001) with a buried template of nanocavities for multiple-junction solar cells

“…Actually, it is observed in the non-implanted SiGe/Si presented in Fig. 1b [28], in which the threading dislocation density can be estimated, with low statistics, at 5 Â 10 5 cm À 2 . After chemical etching, dislocation etch pits are revealed in Fig.…”

“…Stopping and range of ions in matter (SRIM) simulations were used to determine He profiles to pick up the most pertinent implantation parameters [28]; (001) p-type Si wafers were implanted at room temperature with He þ at 10 keV, with a flux of about (9.0 70.3)10 12 cm À 2 s À 1 at high fluences (5 Â 10 15 cm À 2 ) to address the role of the porous layer (position from the surface and porosity) on the relaxation mechanism. The latter was chosen thanks to Monte Carlo simulations giving a He projection range R p of (110 750) nm.…”

“…Depending on the chosen relaxation model [37] or experimental data (mainly the growth temperature), the critical thickness values h c stretches from 6-7 nm to 200-120 nm in the 20-25% Ge composition range [28]. High R value reaching 97.3070.05% has been deduced as compared to those of conventional SiGe layer types (85-93%) [28]. To confirm these results of Ge composition and SiGe thickness, we have also characterized our samples by RBS.…”

“…The 2013 record efficiencies were 28 Numerous architectures of lattice-relaxed Ge (Si) pseudosubstrates (PSs) on Si(001) have been developed earlier for strained SiGe CMOS (complementary metal oxide semiconductor) technology [4]. However these methods have been supplanted by (expensive) SOI and GeOI (silicon or germanium on insulator) [5] wafers, which allows the electrical insulation of CMOS devices.…”