Surface Diffusion of Sb on Si(111) Measured by Second Harmonic Microscopy

Abstract

Surface diffision of Sb on Si(ll1) has been studied by second harmonic microscopy, which uses surface second harmonic generation to monitor surface concentration profiles with a 3 pm spatial resolution. At temperatures near 55% of the bulk melting point and in the coverage range 0 < 6 < 0.12, the activation energy, &iff, and pre-exponential factor, DO, were found to be 60 f 3 kcdmol and 6 x 103*0.' cm2/s, respectively. The high prefactor and activation energy indicate that the surface diffusion is governed by a recently developed adatom-vacancy mechanism.

Impact of directional walk on atom probe microanalysis

“…Also, solutes were often observed to align along specific directions, P was In the case of semiconductors, the very same problems are very likely to affect the data, especially since most APT analysis are performed in laser pulsing mode. Surface migration of various adatoms on Ge [59][60] and Si [61][62] was investigated by several techniques. The difference in the energy barrier for surface migration and desorption was measured to be in the same range (respectively 1.3-2.6 eV and 1.5-3.5 for example for Si [62]).…”

“…Surface migration of various adatoms on Ge [59][60] and Si [61][62] was investigated by several techniques. The difference in the energy barrier for surface migration and desorption was measured to be in the same range (respectively 1.3-2.6 eV and 1.5-3.5 for example for Si [62]). This means that such processes are likely to similarly affect the atom probe microanalysis of some semiconductors, when a pole structure is observed within the desorption map [63].…”

Surface diffusion of Ge on Si(111): Experiment and simulation

“…Through use of second-harmonic microscopy ͑SHM͒, we have examined heterodiffusion of group-III and -V adsorbates on group-IV substrates. 9,[12][13][14] The large values for E and D 0 observed for these systems mimic for heterodiffusion the effects just described for self-diffusion. The close correspondence arises from the known ability of the adsorbates to substitute into the top layer of the substrate.…”

“…Raw second-harmonic images were processed using methods described previously 13 to remove detector shot noise and broadening from the system's optical response function. The resulting profile was converted to the coverage domain using a calibration curve ͑shown in Sec.…”

New Insights into the Origins of Sb-Induced Effects on Self-Catalyzed GaAsSb Nanowire Arrays

“…The results indicate that the Ga adatom adsorbs stronger on a (110) surface in the case of As or Sb adatom presence with an increased adsorption energy by 0.59 and 0.33 eV, respectively. It is worth noting that although the As enhances the Ga binding more than Sb, it has been reported that the surface diffusion of As is much less than that of Sb, 31,35,36 indicating that Sb has more chance to interact with Ga surface adatoms. Thus, we suggest that the higher radial growth rate with increased Sb 2 flux is due to enhanced (temporary) Ga binding to the Sb adatoms adsorbed on the (110) nanowire side-facet surfaces, which reduces the Ga diffusion on the facets and increases the chance for further radial growth.…”