Hydrogen Effects on Heteroepitaxial Growth of Ge Films on Si(111) Surfaces by Solid Phase Epitaxy

Abstract

The influences of hydrogen atoms on Ge heteroepitaxial growth on Si(111) surfaces using solid phase epitaxy (SPE) have been investigated by scanning tunneling microscopy (STM). In the SPE growth of Ge films on H-terminated Si(111) surfaces, the formation of 3-dimensional (3D) Ge islands are suppressed. With the desorption of H atoms, the 3D islands appear on the Ge surface, which are considered to be formed by the agglomeration of Ge atoms. The density of the islands is decreased and the size of the islands is increased by the existence of Si-H bonding at the Ge/Si interface. These phenomena are considered to be caused by the release of the stress in the Ge film and the weakening of the interaction between the Ge film and the Si substrate by Si–H bonding. In addition, the activation energy of the migration of Ge atoms during the agglomeration is determined to be 0.3 eV.

Low-Temperature Growth of Polycrystalline Ge Films on SiO2 Substrate by HDPCVD

“…7,8 However, for thin film transistor ͑TFT͒ applications, successful Ge thin film deposition on SiO 2 substrates using chemical vapor deposition ͑CVD͒ techniques has not been demonstrated so far due to the extremely long incubation times needed. [9][10][11][12][13][14][15] In the present study, we demonstrate the deposition of polycrystalline Ge films directly onto fully SiO 2 covered Si substrates with nearly no incubation time by using high-density plasma CVD ͑HD-PCVD͒ technique at 400°C. X-ray photoelectron spectroscopy ͑XPS͒ and Auger electron spectroscopy ͑AES͒ analyses show that the deposition of very pure Ge thin films can be achieved without significantly detectable O and C incorporations.…”

“…22 Those exposed Si bonds on the surface can then enhance the adsorption probability of Ge atoms and act as the nucleation sites for the subsequent Ge deposition. 10,14 The relationship between the growth rate and the crystallinity of the layers can be explained by the following growth mechanism. The pair correlation function g(r) = density͑r͒/density͑0͒ describes the radial distribution function of the atoms in the crystal on an atomic scale with density͑0͒ as the mean density of the system and density ͑r͒ the probability density to find an atom at the distance r. Therefore, different crystalline structures lead to different characteristic atoms distribution patterns and amorphous structures do not show an or- dered distribution.…”

Properties of Ge Films Grown Through Inductively Coupled Plasma Chemical Vapor Deposition on SiO[sub 2] Substrates

“…9 Successful Ge thin-film deposition directly on SiO 2 substrates using chemical vapor deposition ͑CVD͒ techniques has not been demonstrated previously, however, because an extremely long incubation time is required. [10][11][12][13][14][15][16] Nevertheless, CVD has the advantage of uniformity control which is highly important in the larger dimension substrates and mass production, relative to such techniques as sputtering 17 and e-gun deposition. 18,19 In this paper, we report the physical and electrical properties of Ge films deposited at 300°C using inductively coupled plasma ͑ICP͒-CVD techniques.…”