Growth of InN thin films by modified activated reactive evaporation

Abstract

Indium nitride films have been grown using modified activated reactive evaporation (MARE). The films were grown on glass and silicon substrates at room temperatures, i.e. without any intentional substrate heating. In this technique, the substrates were kept on the cathode instead of the grounded electrode and hence subjected to low energy nitrogen ion bombardment leading to highly c-axis oriented films. The photoluminescence (PL) and Raman spectrum shows significant improvement in the quality of the films compared with conventional activated reactive evaporation. The band gap measured from the room temperature PL was found to be 1.9 eV. Very high growth rates can be achieved in the MARE growth technique. The modification in the activated reactive evaporation technique may have a large impact on the growth of various compounds such as metal oxides.

InN layers grown by MOCVD on substrates

“…The inset shows the squared absorption coefficient a 2 of InN films as a function of photon energy. The a 2 first rises gradually and then steeply to $ 10 9 cm À2 with increasing photon energy, which is the typical absorption intensity for direct bandgap semiconductors [21,22]. The optical band gap is determined to be about 1.07 eV by extrapolating the linear part to a 2 ¼ 0.…”

Annealing studies on InN thin films grown by modified activated reactive evaporation

“…MARE is a combination of conventional activated reactive evaporation (ARE) and biased sputtering. In MARE, the substrates are kept on the cathode instead of ground electrode and hence subjected to low-energy nitrogen ion bombardment [15]. High-purity indium is thermally evaporated in the presence of nitrogen plasma excited by a rf source (13.56 MHz).…”

“…High-purity indium is thermally evaporated in the presence of nitrogen plasma excited by a rf source (13.56 MHz). The films were grown at a plasma power of 100 W, which has shown better structural and optical properties [15]. Though InN films grown at room temperature (without intentional heating), temperature at the substrate was found increasing continuously.…”

“…In our previous work [15] we have grown nitrogen-rich InN thin films by modified activated reactive evaporation (MARE). MARE technique is well-suited for low temperature, large scale deposition of polycrystalline InN thin films.…”

Composition-dependent structural, optical and electrical properties of In x Ga1−x N (0.5 ≤ x ≤ 0.93) thin films grown by modified activated reactive evaporation

“…By this technique, we have grown structurally good quality InN and GaN thin films [21,22], InN films on flexible substrates like polyimide and polycarbonate [23] and also reported room temperature growth of IGN films using a mixed source of indium and gallium [24]. It may be pointed out that due to the difference in the vapour pressures of indium and gallium, it is always difficult to control the In/Ga ratio from a single evaporation source.…”