We report the role of charged species (N2+) on the growth of GaN films by modified activated reactive evaporation (MARE). In MARE technique, substrate is subjected to low energy nitrogen ion bombardment by keeping it in conjunction with the radio frequency cathode. The low energy ion irradiation contributes to the effective formation of GaN as well as in the drastic reduction of the oxygen impurity content by resputtering of the weakly bonded oxygen adatoms. Significant reduction in oxygen impurity can be achieved in the MARE by increasing the concentration of the charged species in the plasma. © 2010 The Electrochemical Society.

Mahaveer K. Jain

Department Of Physics

CHARGED SPECIES

GROWTH OF GAN

LOW ENERGY NITROGEN

LOW-ENERGY ION IRRADIATION

MODIFIED ACTIVATED REACTIVE EVAPORATION

OXYGEN ADATOMS

OXYGEN IMPURITY

Radio frequencies

RE-SPUTTERING

Gallium alloys

Gallium nitride

Ion bombardment

Ions

Oxygen

Ecology

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

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IIT Madras

Role of Charged Species on the Growth of GaN Films by Modified Activated Reactive Evaporation

Electrochemical and Solid-State Letters

Nano-crystalline c-axis orientated indium nitride (InN) thin films were prepared on amorphous polycarbonate, polyimide and glass substrates by modified activated reactive evaporation (MARE) method without any intentional heating of the substrate. The films show strong visible photoluminescence (PL) peak at ~ 1.95 eV indicating the band edge transition which is in good agreement with the optical absorption. The shift in the band gap from reported value is mainly due to Burstein-Moss shift and presence of residual oxygen. InN film grown on inexpensive flexible substrates at room temperature opens opportunity for large scale device applications like solar cells and displays. © 2009 American Institute of Physics.

AIP Conference Proceedings

Room temperature growth of nano-crystalline InN films on flexible substrates by modified activated reactive evaporation

We report the preparation of polycrystalline GaN films on glass substrates by modified activated reactive evaporation (MARE). In this technique, substrates are kept on cathode instead of ground electrode and hence subjected to low-energy nitrogen ion bombardment. With increase in rf power, nitrogen to gallium (N/Ga) ratio in the films and film resistivity monotonically increases whereas oxygen impurity reduces. All GaN films are of wurtzite structure and films grown at higher powers have preferred orientation towards c-axis. Crystalline quality improves with increase in rf power up to ∼150 W and thereafter it degrades. Improvement in crystalline quality can be attributed to Ga/N stoichiometry and reduction in oxygen concentration, whereas degradation can be attributed to the presence of point defects due to excess nitrogen and nitrogen ion bombardment. Optical emission spectroscopy (OES) is used to investigate the relative concentration of excited species during GaN growth. MARE offers a technique to grow low-temperature group III nitride semiconductors. A high deposition rate (4.3 μm/h) was achieved in MARE for growing polycrystalline films on relatively inexpensive substrates. MARE is relatively less complex and offers a viable alternative for large scale growth for polycrystalline GaN thin films. © 2009.

Journal of Crystal Growth

Low-temperature growth of polycrystalline GaN films using modified activated reactive evaporation

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. © 2008 IOP Publishing Ltd.

Journal of Physics D: Applied Physics

Growth of InN thin films by modified activated reactive evaporation

Surface Science

Effectiveness of in situ NH3 annealing treatments for the removal of oxygen from GaN surfaces

Journal of Nanoscience and Nanotechnology

Synthesis and Luminescence Properties of Alumina Encapsulated InN Nanorods

Role of charged species on the growth of GaN films by modified activated reactive evaporatione

Journal	Electrochemical and Solid-State Letters
ISSN	10990062
Open Access	No