Chemical vapor deposition of silicon–germanium heterostructures

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.…”

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

“…In reference [24], we described the procedure of SiGe layers growth in details. At moderate growth temperature, a decrease of the adatoms mobility inhibits the formation of undulations of the SiGe layer [25] due to the Stranski-Krastanov growth mode or surface instabilities, leading to a low final surface roughness.…”

“…However, there are several restrictions for growing thick BL at low temperature by CVD, such as the decrease of the growth rate due to the dynamic hydrogen coverage [24] or the low adatoms mobility and the high defect density (about 10 5 -10 7 cm À 2 ) that lead to an increase of the root-mean-square surface roughness (RMS) with the deposited thickness [29,30]. Otherwise, the Si BL growth temperatures are usually 600 1C in the UHV-CVD mode or 700 1C in the LP-CVD mode [24].…”

Si/SiGe near-infrared photodetectors grown using low pressure chemical vapour deposition

“…There are various CVD designs depending on the different epitaxy requirements. For the growth of SiGe on Si substrates, ultra-high vacuum CVD [8][9][10], rapid thermal CVD, remote plasma-enhanced CVD [11], and other low pressure CVD techniques have been reported [12]. The apparatus used in this report, is low pressure CVD equipment, designed and built at Southampton University [15].…”

“…Meanwhile, 3D SiGe islands provides the possibility of enhanced sensitivity in the near-and mid-IR ranges. To produce 3D SiGe nanostructures, surface controlled reactions and nucleations must be considered and self-assembled growth, exploiting Ge surface segregation and strain relaxation under specific growth conditions and relatively low temperature [12,14].…”