Narrow Results

We have investigated the nitrogen lattice location in MOVPE grown Ga_1-xIn_xN_yAs_1-y with x = 0.07 and y = 0.025 by means of ion beam channeling technique. In this system, the lattice constant of the Ga_1-xIn_xN_yAs_1-y film is equal to GaAs lattice. Therefore, we can grow apparently no strain, high quality and very thick GaInNAs film on GaAs substrate. The quality of the films as well as the lattice location of In and N were characterized by channeling Rutherford backscattering spectrometry and nuclear reaction analysis using 3.95 MeV He²⁺ beam. The fraction of substitutional nitrogen in the film was measured using the ¹⁴N(α,p)¹⁷O endothermic nuclear reaction. Our results indicate that more than 90% of In and N atoms are located the substitutional site, however, N atoms are slightly displaced by ~0.2 Å from the lattice site. We suggest that the GaInNAs film has a local strain or point defects around the N atoms.

A novel nanofabrication technology to produce dense arrays of silicon nanowhiskers up to 20 nm high has been developed. This rapid and simple technology employs electron beam rapid thermal annealing (EB-RTA) of untreated silicon. Pre-implantation of the silicon substrate with nitrogen at low energy (5 keV) has been shown to suppress the formation of these nanostructures. In this paper we demonstrate identical silicon nanostructure growth suppression when produced following nitrogen ion implantation at 50 keV and 100 keV. Specimens were implanted at room temperature and subsequently annealed at 1000°C for 15 s (temperature gradient 5°Cs^-1). Specific results obtained from AFM and NRA analysis are discussed highlighting the possibility of silicon nanowhisker growth control using nitrogen ion implantation.

Analysis using MeV ion beams is a thin film characterisation technique invented some 50 years ago which has recently had the benefit of a number of important advances. This review will cover damage profiling in crystals including studies of defects in semiconductors, surface studies, and depth profiling with sputtering. But it will concentrate on thin film depth profiling using Rutherford backscattering, particle induced X-ray emission and related techniques in the deliberately synergistic way that has only recently become possible. In this review of these new developments, we will show how this integrated approach, which we might call "total IBA", has given the technique great analytical power.

Analysis using MeV ion beams is a thin film characterisation technique invented some 50 years ago which has recently had the benefit of a number of important advances. This review will cover damage profiling in crystals including studies of defects in semiconductors, surface studies, and depth profiling with sputtering. But it will concentrate on thin film depth profiling using Rutherford backscattering, particle induced X-ray emission and related techniques in the deliberately synergistic way that has only recently become possible. In this review of these new developments, we will show how this integrated approach, which we might call “total IBA”, has given the technique great analytical power.