Low-temperature copper-induced lateral growth of polycrystalline germanium assisted by external compressive stress

Abstract

Articles you may be interested inEffect of bilayer geometry on the diffusion of Ni in amorphous Si and the consequent growth of silicides J. Vac. Sci. Technol. B 30, 061203 (2012); 10.1116/1.4757134Hydrogenation-assisted nanocrystallization of amorphous silicon by radio-frequency plasma-enhanced chemical vapor depositionCopper-induced lateral growth of polycrystalline germanium ͑poly-Ge͒ at temperatures as low as 150°C was enabled by the application of an external mechanical stress during the annealing step of sample processing. An equivalent compressive strain of 0.05% was externally applied at 150°C for 10 h to a deposited amorphous Ge layer and crystalline growth rates of 2.5 and 1.8 m / h were observed in directions parallel and perpendicular to the stress axis, respectively. These results were confirmed by scanning electron microscope and transmission electron microscopy ͑TEM͒ analyses. In addition, TEM and x-ray diffraction analyses indicate that a fraction of poly-Ge annealed in the presence of applied compressive stress possessed a tetragonal structure with space-group P4 3 2 1 2. The presence of the tetragonal phase is hypothesized to be the primary mechanism responsible for the lateral growth of poly-Ge.

Stress evolution of Ge nanocrystals in dielectric matrices

“…For the sample experiencing largest compressive stress, crystallization starts at around 775 °C, however for the sample with tensile stress this temperature is 1000 °C. This is in agreement with works of several groups who reported the relation between stress and crystallization [29,34,35]. As tensile strain increases, the strain energy at the Ge NC surface increases, and the Ge-Ge bonds become more stretched at the surface of the Ge NC.…”

“…For these samples, the crystallization temperature threshold is between 800 °C and 850 °C. This is in agreement with work in [29]. In that work, it was shown that application of an external mechanical compressive stress during annealing for copper-induced growth of polycrystalline Ge leads to enhancement of crystallization.…”

Electrodeposition of Cu-Doped MoS2for Charge Storage in Electrochemical Supercapacitors

“…This may reflect Cuinduced crystallization when MoS 2 is annealed, since Cu-induced crystallization of other semiconductors such as Si and Ge has been reported. 35,36 The best insight into the Cu-doped MoS 2 thin film structure, composition and phase is provided by the XRD results of Figure 4. The XRD patterns are virtually identical for undoped and Cu-doped MoS 2 , despite the sulfur deficiency in the Cu-doped films from both the RBS and EDX analyses.…”

Low Temperature Metal-Induced Lateral Crystallization of Si1-xGex Using Silicide/Germanide-Forming-Metals

“…MILC of Si has been extensively studied, and the preferred metal is Ni due to small lattice mismatch between NiSi 2 and Si. Similar to Si, when Ge is in contact with a suitable metal such as Cu, 15) Al, 16) Au, 17) Ni, 18,19) Co, 20) or Pd, 21) its crystallization temperature is reduced. However, compared to the number of studies on MILC of Si, fewer works have been done on Ge rich SiGe and Ge, in which the choice of seed metal is still not obvious.…”