Kumar, S. and Parashar , A. and Rauthan , C. M. and Singhal , S. K. and Dixit , P. N, and Singh , B. P. and Bhattacharyya, R. (2008) Morphological Observation of Y and T Junctions in Nanostructured Boron Nitride Thin Films. Journal of Nanoscience and Nanotechnology, 8 (7). pp. 3526-3531. ISSN 1533-4880

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Abstract

Formations of Y and T nano junctions have been observed in boron nitride films deposited on silicon substrates by plasma chemical reaction of diborane (B2H6 diluted in hydrogen) and ammonia (NH3) gases using dual frequency (microwave/radio) plasma enhanced chemical vapor deposition technique without any intentional heating of the substrates. It has been observed that these nano junctions form at a critical feed gas ratio of ammonia and diborane. We have investigated the effect of gas feed ratio R (=NH3/B2H6) in the plasma reaction chamber, keeping all other deposition parameters constant, on the morphology of boron nitride films. The deposited films are characterized by SEM, AFM, TEM and Laser Raman. For gas feed ratio, R < 100, octahedron and cubic morphologies have been observed in BN films and on increasing R to >100, size of the crystallites reduces to nanometer level. In some of our BN samples deposited at a critical value of gas ratio (R = 400), uniform Y and T junctions having bamboo like morphologies, in nanometer level, have been observed, which we wish to emphasis here as an interesting and newer observation in boron nitride films deposited by the dual frequency PECVD technique. This change in morphology exhibited by varying gas feed ratio is mainly due to excess nitrogen ions in the plasma.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Scientific Publishers.
Uncontrolled Keywords:	Boron Nitride, Y and T Junctions, PECVD, Nanostructures, Morphology.
Subjects:	Chemistry Materials Science Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	17 Apr 2015 07:50
Last Modified:	17 Apr 2015 07:50
URI:	http://npl.csircentral.net/id/eprint/1105

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