Structural characteristics of AlN films deposited by pulsed laser deposition and reactive magnetron sputtering: A comparative study

Abstract

Aluminum nitride films have been deposited on Si͑111͒ substrates at different substrate temperatures using two techniques; pulsed laser deposition or reactive magnetron sputtering. The films deposited by either of the techniques have been characterized by x-ray diffraction and transmission electron microscopy to determine the crystalline quality, grain size, and epitaxial growth relation with respect to the substrate. The bonding characteristics and the residual stresses present in the films have been evaluated using Raman and Fourier transform infrared spectroscopy. Secondary ion mass spectrometry has been performed to determine the nitrogen stoichiometry and the presence of impurities such as oxygen and silicon. The adhesion strength of the AlN films to the silicon substrate and the wear resistance have been determined by scratch test and a specially designed microscopic wear test. A comparison of the different characteristic features associated with the AlN films deposited by pulsed laser deposition or magnetron sputtering is presented with particular emphasis to electronic and tribological applications.

Nanoparticles of wurtzite aluminum nitride from the nut shells

“…This shift in peak position is consistent with the shifts reported by Balasubramanian et al for nanoparticles and nanotubes of AlN. 18,19 The transmission electron micrographs for almond and walnut shells are presented in Fig. 3 showing the nanodimensionality of the AlN crystallites.…”

Comment on “Ion-assisted pulsed laser deposition of aluminum nitride thin films” [J. Appl. Phys. 87, 1540 (2000)]

“…8 Lu et al, on the other hand, reported infrared absorption bands at ϳ750 cm Ϫ1 , i.e., with a frequency shift of ϳ80 cm Ϫ1 in relation to the expected value. A similar, but smaller shift ͑ϳ35 cm Ϫ1 ͒ was also observed by Jagannadham et al 5 and was attributed to the residual stress in the AlN films. Indeed, a recent work by Kuball et al studying the effects of hydrostatic pressure on the vibration modes of AlN can help us to understand these results.…”

“…This is a promising result since most of the good quality crystalline AlN films are usually deposited at rather high temperatures, incompatible with the present technologies. 4,5 The technological consequences of these results motivated us to carefully scrutinize the Raman and infrared data leading Lu et al to such substantial conclusions. We found, however, that the analyses of Lu et al probably contain inaccuracies regarding the true crystalline quality of their AlN films.…”

Low temperature growth of c-axis oriented AlN films on γ-LiAlO2 by radio frequency magnetron sputtering

“…The crystallite size calculated from the Scherrer's equation [18] of X-ray line broadening increased from 7.3 to 15.0 nm. Fig.…”

“…So other sources of atomic or ionic nitrogen are essential to form high quality AlN films [18]. Considering the possible stoichiometric deviation of the present AlN films, we introduced N 2 to the sputtering ambient with different concentrations at different T s .…”