Structure of arsenic-treated indium phosphide (001) surfaces during metalorganic vapor-phase epitaxy

Abstract

We have studied the initial stages of heterojunction formation during the metalorganic vapor-phase epitaxy of indium arsenide on indium phosphide. Exposing an InP ͑001͒ film to 10 mTorr of tertiarybutylarsine below 500°C results in the deposition of a thin InAs layer from 1.5 to 5.0 atomic layers thick ͑2.3-7.5 Å͒. The surface of this epilayer remains atomically smooth independent of arsenic exposure time. However, in an overpressure of tertiarybutylarsine at or above 500°C, the arsenic atoms diffuse into the bulk, creating strained InAsP films. These films form three-dimensional island structures to relieve the built-up strain. The activation energy and pre-exponential factor for arsenic diffusion into indium phosphide have been determined to be E d ϭ1.7Ϯ0.2 eV and D o ϭ2.3Ϯ1.0ϫ10 Ϫ7 cm 2 /s.

Self-Catalyzed Growth and Characterization of In(As)P Nanowires on InP(111)B Using Metal-Organic Chemical Vapor Deposition

“…Due to the limited solubility of P and As (in both liquid at the growth temperature, 375 °C, and solid at room-temperature phases of In [ 46 ], In-P [ 47 ], and In-As [ 48 ]) and the diffraction spot in Fig. 2 d (enclosed by a green circle) corresponding to tetragonal-structured In (or In-rich alloy), we expect that the concentrations of P and As in the wire tip are negligible [ 49 ]. Similar results have been reported for In-catalyzed growth of InP and InPSb nanowires [ 31 , 32 ].…”

Finite-size effects and analytical modeling of electrostatic force microscopy applied to dielectric films

“…where ε 0 is the permittivity of vacuum and c 0 is an irrelevant constant (the remaining parameters have all been already defined). This expression is reminiscent of the expression valid for metallic substrates introduced by Hudlet et al [23,24] if z is substituted with z + h/ε r , a type of substitution first suggested in [21] in the context of EFM. We previously showed the validity of equation (3) in the thin film limit with both direct capacitance measurements and finite-element numerical calculations [3][4][5].…”

“…For the cone contribution, we also generalize the expression valid for metallic substrates [23,24] to thin dielectric films by substituting z with z + h/ε r [21], thus obtaining where all parameters were previously defined. Note that for large tip radii and small tip-substrate distances (typically R > 100 nm and z + h/ε r < 100 nm), the cone contribution in equation ( 5) becomes practically independent from z and its variation with distance is negligible.…”

“…In the modeling of planar dielectrics, the samples are typically modeled as laterally infinite [22], in analogy with the case of metallic substrates [23,24]. In some studies, lateral finite-size effects have been considered by using simplified models that give physical insight into the problem, but do not allow accurate quantification of the experimental data [25,26].…”