Interstitial oxygen in elemental and compound semiconductors: fundamental properties and trends

Abstract

The equilibrium structure, electronic properties and potential energy surfaces of interstitial oxygen (Oi) in c-C, Si, BP, AlP, c-SiC and c-BN are calculated in small and large molecular clusters. The theoretical level ranges from the 'approximate ab initio' Hartree-Fock method of partial retention of diatomic differential overlap to large-basis-set ab initio Hartree-Fock followed by second-order corrections for electron correlation (MP2). The equilibrium site is a puckered bridged bond in all hosts. In compound semiconductors, Oi has a larger degree of bonding with the most electronegative of the two host atoms (P, C or N) than with the least electronegative one and puckers in a direction that maximizes the overlap with its second-nearest neighbour. The dipole moment of the defect and the barrier for reorientation of Oi around and through the (111) axis are calculated. In order to estimate the relative stability of Oi in the various hosts, we determine the energies involved in inserting molecular O2 into the lattice and dissociating it into two isolated Ois. Finally, we calculate the barriers for migration of Oi between adjacent equilibrium sites. There are two such barriers in compound semiconductors. Whenever possible, we correlate the properties of Oi with various properties of the host, such as its and length and its ionic character, in order to gain predictive insight into the fundamental properties of interstitial oxygen in semiconductors.

Atomic-Scale Mechanisms of Oxygen Precipitation and Thin-Film Oxidation of SiC

“…Single O atom.-We start by describing the properties of one oxygen atom in cubic SiC for which there is some prior work [15]. In agreement with that work, we find that an oxygen molecule is not stable in SiC because of the relatively small interstitial volume.…”

Isolated oxygen defects in3C- and4H-SiC: A theoretical study

“…[9][10][11] The geometry obtained in the present calculation is practically the same as the result of earlier calculations ͑see Fig. 4͒.…”

“…9,10 DiVentra and Pantelides found that oxygen clustering in the ͑110͒ plane in 3C-SiC could be energetically feasible in a manner very similar to the possible core of the thermal double donors in silicon. 10 In an earlier work we calculated interstitial and substitutional oxygen in the neutral state in a molecular cluster model of 3C-SiC, 11 but neither relative stabilities nor occupancy levels were given.…”

Oxygen-dislocation interactions in silicon at temperatures below 700 °C: Dislocation locking and oxygen diffusion

“…It has been shown that an oxygen molecule in Si is not stable and dissociates with a large gain in energy. 17 The proposal that oxygen dimer is the fast diffusing species required to explain anomalous oxygen transport seems to be gaining strength since it can explain a number of experimental findings. Theoretical studies have shown that the oxygen dimer has stable configurations and can migrate with an activation energy of about 1.5 eV.…”