8 research outputs found
Response of magnetron sputtered AlN films to controlled atmosphere annealing
The present investigation deals with the examination of the response of amorphous AlN films to post-deposition annealing environments such as high vacuum (HV) and nitrogen atmosphere (NA). The c/a ratio values from GIXRD for both cases are around 1.602. The XPS profile of NA-AlN shows a deficiency of nitrogen on the surface, whereas the oxygen impurity level is negligible in the case of NA compared with HV. The PL spectra substantiate the nitrogen vacancies in NA-AlN. The amorphous AlN exhibits a nanoindentation hardness of 18 GPa
Nanomechanical and optical properties of highly a-axis oriented AlN films
This paper reports optical and nanomechanical properties of predominantly a-axis oriented AlN thin films. These films were deposited by reactive DC magnetron sputtering technique at an optimal target to substrate distance of 180 mm. X-ray rocking curve (FWHM = 52 arcsec) studies confirmed the preferred orientation. Spectroscopic ellipsometry revealed a refractive index of 1.93 at a wavelength of 546 nm. The hardness and elastic modulus of these films were 17 and 190 GPa, respectively, which are much higher than those reported earlier can be useful for piezoelectric films in bulk acoustic wave resonators
Continuous multi cycle nanoindentation studies on compositionally graded Ti<SUB>1-x</SUB>Al<SUB>x</SUB>N multilayer thin films
Two types of Compositionally Graded Multilayer (CGM) films of Ti1-xAlxN consisting
of 21 layers were synthesized by reactive magnetron co-sputtering technique. The first one begins with a layer of
Ti0.4Al0.6N from substrate and ends with TiN, whereas exactly a reverse order has been
followed in the second one. As deposited CGM films are poly-crystalline with rocksalt structure similar to
stoichiometric TiN. Secondary Ion Mass Spectrometry (SIMS) depth profile of the films showed the presence of 21
layers of equal thickness (50 nm) with varying aluminum content in steps. Continuous Multi-Cycle (CMC)
nanoindentation technique was used to analyze the failure modes of these films. Topographic examination of the
indented zone revealed the presence of edge cracks inside and outside the indentation area when the load exceeds
beyond 90 mN. The Load-displacement profiles of CMC and single indentations exhibited the onset of pop-ins at a
depth of ~200 nm
Nanomechanical and optical properties of highly a-axis oriented AlN films
This paper reports optical and nanomechanical properties of predominantly a-axis oriented AlN thin films. These films were deposited by reactive DC magnetron sputtering technique at an optimal target to substrate distance of 180 mm. X-ray rocking curve (FWHM = 52 arcsec) studies confirmed the preferred orientation. Spectroscopic ellipsometry revealed a refractive index of 1.93 at a wavelength of 546 nm. The hardness and elastic modulus of these films were 17 and 190 GPa, respectively, which are much higher than those reported earlier can be useful for piezoelectric films in bulk acoustic wave resonators. (C) 2012 American Institute of Physics. http://dx.doi.org/10.1063/1.4772204