Theoretical approach to influence of As2 pressure on GaAs growth kinetics

e-J. Surf. Sci. Nanotech.

Nakamura

et al. 2015

The effects of Zn atoms as a dopant on the surface structure and initial growth processes on InP(111)B substrate are theoretically investigated on the basis of surface phase diagrams which are obtained by comparing the adsorption energy given by ab initio calculations with the gas-phase chemical potentials. The calculated surface phase diagrams demonstrate that the Zn-incorporated surface is stabilized under the growth conditions with high Zn supply ratio. Furthermore, In atoms tend to easily adsorb on the Zn-incorporated surface as an In-P dimer due to the formation of Zn-P and P-P bonds, implying that the adsorption of In atoms and resultant growth processes are promoted on the Zn-incorporated InP(111)B surface which is stabilized under Zn-rich conditions. These results suggest that effects of Zn doping on the surface structure and initial growth processes are crucial for understanding the bidirectional growth mechanisms of InP nanowires on InP(111)B substrate.

Section: Methodsmentioning

confidence: 99%

Effects of Zn Doping on the Surface Structure and Initial Growth Processes of InP Thin Film Layers on InP(111)B Substrate

Kato

e-J. Surf. Sci. Nanotech.

Nakamura

et al. 2015

“…We proposed an ab initio-based approach that incorporates the free energy of ideal gas per one particle (chemical potential) µ gas [5,6]. The adsorption-desorption behavior of In atom and As molecule on these surfaces can be determined by comparing µ gas with the adsorption energy E ad .…”

Section: Methodsmentioning

confidence: 99%

Recent Progress in Computational Materials Science for Semiconductor Epitaxial Growth

2017

Crystals

Recent progress in computational materials science in the area of semiconductor epitaxial growth is reviewed. Reliable prediction can now be made for a wide range of problems, such as surface reconstructions, adsorption-desorption behavior, and growth processes at realistic growth conditions, using our ab initio-based chemical potential approach incorporating temperature and beam equivalent pressure. Applications are examined by investigating the novel behavior during the hetero-epitaxial growth of InAs on GaAs including strain relaxation and resultant growth mode depending growth orientations such as (111)A and (001). Moreover, nanowire formation is also exemplified for adsorption-desorption behaviors of InP nanowire facets during selective-area growth. An overview of these issues is provided and the latest achievement are presented to illustrate the capability of the theoretical-computational approach by comparing experimental results. These successful applications lead to future prospects for the computational materials design in the fabrication of epitaxially grown semiconductor materials.

“…where ζ rot and ζ vibr are the partition functions for the rotational motion and the vibrational motion, respectively [8]. Similar equation with different expressions of the partition functions ζ rot and ζ vibr from those for As 2 is used for the chemical potential µ As4 of As 4 in the vapor phase.…”

Section: Computationalmentioning

confidence: 99%

“…The unit super cell consists of six atomic layers of GaAs, an atomic layer of fictitious H atoms and a vacuum region equivalent to about 15 atomic layers in thickness. Details of ab initio calculations have been set in previous studies [4][5][6][7][8]11].…”

Section: Computationalmentioning

confidence: 99%

An ab initio-based approach to phase diagram calculations for GaAs(001) surfaces

Ishizaki

e-J. Surf. Sci. Nanotechnol.

et al. 2005

Surface phase diagram of GaAs (001) is systematically investigated by using our ab initio-based approach. The phase diagrams of the c(4 × 4) and (2 × 4) surfaces are clarified as functions of temperature and As pressure. The calculated results reveal that c(4 × 4)β and (2 × 4)γ surfaces are strongly affected by As-molecular species such as As2 and As4. The c(4 × 4)β surface consisting of As dimers disappears under As4 because of small desorption energy of As dimers. The (2 × 4)γ surface appears only at high As pressure and low temperatures buried in the stable region of c(4 × 4)β under As4. These results are compared with experimental results to check the versatility of our approach to the surface phase diagram calculations.