Selective epitaxial growth of compressively strained Ge layers on Si in 40-nm trench arrays

Characterization of residual strain in epitaxial Ge layers grown in sub-100 nm width SiO2 trench arrays

“…In the TEM images, all three samples show faceted top surfaces regardless of the pattern size. Analysis of the well-developed facets indicated that they were (001), (113), and (111) planes [26]. In the Ge layers, a high density of stacking faults and dislocations was observed in the bottom part of the Ge layers, particularly in the case of S90/O40 (see the arrows in Fig.…”

“…Under the same Ge volume, the development of surface undulations between the SiO 2 walls becomes energetically more difficult with decreasing L Si , which is due to an increase in the Ge/SiO 2 interface effect that contributes to the total Gibbs free energy. Since the epitaxial growth of the Ge layers on blanket Si is a limiting case where the value of L Si approaches infinity, the surface stability is not influenced by the Ge/SiO 2 interfaces and eventually epitaxial Ge films release their strain energy through an island growth mode [26]. In addition, the nominal thicknesses of the Ge layers deposited on S40/O30, S65/O65, and S90/ O40 were 150, 145, and 135 nm, respectively.…”

“…For instance, we reported that compressively strained Ge layers can be grown on 40-nm width SiO 2 trench arrays [26,27]. We demonstrated that the residual in-plane strains along two directions, parallel and perpendicular to the SiO 2 walls, can be independently measured through high resolution X-ray diffraction (HR-XRD) reciprocal space mapping (RSM).…”

Selective epitaxial growth of stepwise SiGe:B at the recessed sources and drains: A growth kinetics and strain distribution study

“…Cyclic deposition and etching (CDE) was applied to achieve SEG. [11][12][13][14][15][16] Unlike the co-flow process, by which precursors and HCl and/or Cl 2 etchant were simultaneously supplied into the chamber, 17 separated deposition and etching steps made up 1 cycle of the CDE process. During the deposition step, SiGe was simultaneously nucleated on Si and nitrides.…”

“…4,6,7 The sensitivity and resolution of the Nano Beam Diffraction (NBD) method is comparable to other methods, and the sample preparation procedure is relatively simple. [8][9][10] Recent studies using the NBD method have reported strain evolution in epitaxial Ge layers in narrow oxide trenches, 11,12 and strain distribution in fin-FET structures was reported using a combination of NBD and the finite element method (FEM). 13 In the present study, we report the crystallinity and strain distribution of epitaxial Si 1-x Ge x selectively grown by UHV-CVD.…”