Electrical depth profile of p-type GaAs/Ga(As, N)/GaAs heterostructures determined by capacitance–voltage measurements

Abstract

Capacitance–voltage measurements on metal-semiconductor contacts are used to examine depth-resolved electrical characteristics of GaAs/Ga(As, N)/GaAs heterostructures. The experimental depth profiles of the carrier concentration are compared with calculations based on self-consistent solutions of the Poisson equation. As-grown Ga(As, N) layers are p type, and hole concentrations of about 3×1016 cm−3 are observed for undoped Ga(As, N) layers with a GaN mole fraction of 3% and thicknesses below 80 nm. This hole concentration is stable during rapid thermal annealing. For a GaN mole fraction of about 3%, the valence band offset between GaAs and Ga(As, N) is found to be +(11±2) meV. The heterointerfaces are of type I. The dominant carrier depletion in as-grown heterostructures is due to donor-like defect levels, which are accumulated at the GaAs-on-Ga(As, N) interface. The amount of these interfacial defects rises remarkably in thicker Ga(As, N) layers, but can be completely removed by rapid thermal annealing after growth. By release spectroscopy, further hole traps with definite level energies are distinguished at the Ga(As, N)-on-GaAs interface, which are probably due to the specific GaAs growth conditions.

Electrical properties of nitrogen‐related defects in n‐type GaAsN grown by molecular‐beam epitaxy

“…Polyakov et al [14] and Jenn-Fang et al [15] had reported a similar defect which was attributed to interfacial defect. P. Krispin et al [16] also detect this trap in p-type GaAsN samples and point that to interfacial trap center.…”

Characterization of deep-level defects in GaNAs/GaAs heterostructures grown by APMOVPE

“…It is generally known that while the undoped GaAs is usually n-type, a dilute GaNAs can be p-type or n-type, depending on the growth conditions and the type of elemental sources used in different growth techniques. The results presented in the literature indicate that as-grown, unintentionally doped GaNAs grown by MOVPE [13,14] or MBE [15] is usually p-type, however for example a CBE growth can result in the n-type GaNAs material [16]. It has been speculated that this ptype background doping is a result of unintentional carbon contaminations [1,17,18].…”

Observation of defect complexes containing Ga vacancies in GaAsN

“…However, also the valence band changes a little, and it has been recently shown that GaAsN/GaAs material system has type-I band alignment. 6,7 Various defects are formed in the material during the growth, and post-growth annealing can be used to eliminate some of them. 8,9 Intrinsic point defects identified in the arsenide-nitrides so far are an As Ga antisite, 10,11 an N interstitial, [12][13][14] and a Ga vacancy.…”