Low-temperature deposition of cubic boron nitride thin films

A. Bonizzi; R. Checchetto; A. Miotello; P. M. Ossi

doi:doi:10.1209/epl/i1998-00518-y

DOI: 10.1209/epl/i1998-00518-y

Europhys. Lett, 44 (5), pp. 627-633 (1998)

Low-temperature deposition of cubic boron
nitride thin films

A. Bonizzi ¹, R. Checchetto ², A. Miotello ² and P. M. Ossi ³

¹ Dipartimento di Ingegneria Nucleare, Politecnico di Milano - I-20133 Milano, Italy
² Istituto Nazionale per la Fisica della Materia (INFM) and Dipartimento di Fisica
Università di Trento - I-38050 Povo (TN) Italy
³ Istituto Nazionale per la Fisica della Materia (INFM) and
Dipartimento di Ingegneria Nucleare, Politecnico di Milano - I-20133 Milano, Italy

(received 21 July 1998; accepted in final form 15 October 1998)

PACS. 64.70Kb - Solid-solid transitions.
PACS. 68.55Jk - Structure and morphology; thickness.
PACS. 81.15Cd - Deposition by sputtering.

Abstract:

BN thin films have been deposited on (100)-oriented Si wafers by radio frequency (RF) magnetron sputtering using r.f. target power in the $100 \div 200\;{\rm W}$ range and substrate bias voltage in the $-50 \div -130\;{\rm V}$ range, while maintaining a low substrate temperature ( $T<400\;{\rm K}$ ). Film characterization has been performed by using Fourier Transform Infrared Spectroscopy (FTIR), Micro-Raman Spectroscopy, X-ray Diffraction (XRD) and nanoindentation measurements. With appropriate choice of the bias voltage BN films with predominant cubic phase (90 at. %) can be obtained. The deposited layers are nearly stoichiometric (the B/N atomic composition ratio is $1.1\div 1.2$ ) and present a considerable nanohardness value ( $\rm \sim 30\; GPa$ ); structural analysis shows grain size in the nanometric range, thus giving rise to strong phonon confinement effects.

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