Characterization of processing-induced defects in high-purity InP by photoluminescence

Abstract

Low-temperature photoluminescence experiments were performed on high-purity InP substrates as a function of heat treatment, flat-profile ion implantation and subsequent annealing procedures. Whereas the well resolved near band edge luminescence proved the superior substrate quality, up to 6 sharp luminescence lines (some of them not reported so far) and one shallow broad-band emission were observed after Si3N4 deposition and various annealing procedures. From the temperature dependence of the luminescence peak intensities the activation energies of the novel lines were determined and discussed in terms of excitons bound to processing-induced complex defects. These assignments are supported by the observation of a strong enhancement of the luminescence after low dose Ar+ ion implantation.

Dielectric properties of semi-insulating Fe-doped InP in the terahertz spectral region

“…Nominally pure InP crystals contain different unintentional impurities due to the growth processes with the concentrations up to 5·10 15 cm −3 . The most common unintentional impurities in the SI InP are Si, S, Zn, C 15 , 17 . In order to trap the free carriers produced by these impurities, InP crystals are doped with iron that creates acceptor levels in the mid-gap region of InP 7 .…”

High-resolution photoinduced transient spectroscopy as a new tool for quality assessment of semi-insulating InP

“…The results shown in table 2 indicate that the defect structure of SI InP:Fe is very complex and the material properties are affected by a number of various point defects. Trap T1 (10 meV) is likely to be attributed to shallow donor impurities such as sulfur in the phosphorus sublattice or silicon in the indium sublattice [6,7]. The ionization energy of these donors is around 6 meV [7].…”

“…The ionization energy of these donors is around 6 meV [7]. Trap T2 (20 meV) can be assigned to shallow acceptor impurities such as silicon in the phosphorus sublattice or zinc in the indium sublattice [6,7]. The ionization energy of these acceptors is around 30 meV [7].…”

“…On the other hand, it has been suggested that iron in InP is compensated by a shallow donor related to the 2316 cm −1 local vibration mode (LVM) assigned to the fully hydrogenated indium vacancy V In H 4 [16]. Trap T3 (50 meV) is presumably another shallow donor formed, however, by a native defect or a native defect-impurity complex [6,7]. Traps T4 (60 meV) and T5 (80 meV) we assumed as unknown, for we have not managed to find any reference on the properties to defects corresponding to these traps.…”

“…Thus, at a temperature below 200 K the lifetime starts to be determined by band-to-acceptor (BA), band-to-band (BB), donor-acceptor (DA) and donor-to-band (DB) transitions. The probability of these transitions decreases with decreasing temperature and the lifetime increases [6,17]. To some extent, the temperature dependence of the µτ product is also affected by the changes in the electron mobility.…”