Effects of nitrogen incorporation in InSb1−xNx grown using radio frequency plasma-assisted molecular beam epitaxy

Abstract

InSb 1−x N x was grown by radio frequency plasma-assisted molecular beam epitaxy. The effect of nitrogen plasma power ͑200-500 W͒ and growth temperature ͑330-420°C͒ on nitrogen incorporation was investigated. A combined analysis involving x-ray diffraction, x-ray photoelectron spectroscopy, and secondary ion mass spectroscopy measurements indicates that the dominant nitrogen defect is interstitial N-Sb. Increasing the plasma power resulted in increase in the interstitial N-Sb amount rather than the substitutional N Sb amount. For fixed plasma power, decreasing the growth temperature helped reduce the interstitial N-Sb defect. Under the experimental conditions, the average value of substitutional N is approximately 1.6%-2%.

Optical properties and bonding behaviors of InSbN alloys grown by metal-organic chemical vapor deposition

“…From the area covered by each type of bonding over the total area of the spectrum, the contributions of the four types of N bonds are 27% (In-N), 13% (In-N-Sb), 46% (Sb-N) and 14% (N-N), respectively. It means that most of the incorporated N occupies the position of In and forms N-Sb bonds as antisite defects, which is different from the samples grown by MBE or direct N implantation [2,12]. The antisite defects in a single crystal may not contribute to the bandgap reduction but do contribute to the lattice mismatch.…”

“…Theoretical calculation using k.p model reveals that the N content x required for a band gap reduction of 0.1 eV in InSb 1 À x N x alloy is only about 0.01 [7], which is much lower than those required for other alloys like InAsSb, InTlSb and InSbBi [8][9][10]. So far, the InSbN alloys reported are mostly fabricated by molecular beam epitaxy (MBE) and ion implantation techniques [11][12][13]. There is also a report on InSbN alloys grown by a metalorganic chemical vapor deposition (MOCVD) technique [14], but only limited information is available, to the best of our knowledge.…”

Effect of thermal annealing on properties of InSbN grown by molecular beam epitaxy

“…Since our current range of annealing temperature is much lower than the established dissociation temperature ͑Ͼ550°C͒ of strong N-In bonds, 15 the annealing process most likely removes the N-N interstitials. 12 In fact using the lattice mismatch model reported by Pham et al,4,16 the defects that can contribute to the tensile strain are ͓100͔-split interstitial N-N and ͓110͔-split interstitial N-N. Second, no significant change in total N content after annealing was obtained from SIMS. This means that N is not likely to out diffuse from our bulk structures.…”

“…2,3 Recent progress in radio frequency ͑rf͒ molecular beam epitaxy ͑MBE͒ has led to encouraging achievements in this material growth such as an increased N incorporation. 4 Nevertheless in this growth technique, 5 the commonly known problem lies in its high intrinsic background electron concentration ͑n e ͒ of ϳ10 18 cm −3 even through N is an isoelectronic acceptor. 6,7 The most likely causes of high n e can be attributed to N interstitials since the rf plasma source can create charged species.…”

“…Such N source is expected to generate more neutral atomic N. 4 The average growth rate was 1 m / hr and the Sb/In flux ratio was kept at ϳ2 which is Sb stabilized condition. Due to the large lattice mismatch between GaAs and InSb, a two-step InSb buffer layer was first grown to suppress dislocations prior to the InSbN epilayer growth.…”