Pulsed radio frequency plasma deposition of a-SiN{sub x}:H alloys: Film properties, growth mechanism, and applications

Journal Article · Fri Sep 15 04:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2349565· OSTI ID:20884726

Vernhes, R; Zabeida, O; Klemberg-Sapieha, J E; Martinu, L ^[1]

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1. Regroupement quebecois sur les materiaux de pointe (RQMP) and Department of Engineering Physics, Ecole Polytechnique de Montreal, P.O. Box 6079, Station Centre-Ville, Montreal, Quebec, H3C 3A7 (Canada)

In this work, we propose a fabrication process of a-SiN{sub x}:H alloys by pulsing the radio frequency (rf) signal in a low pressure plasma-enhanced chemical vapor deposition (PECVD) system. The characteristics of the films can be controlled simply by adjusting the duty cycle of the pulsed rf power, while keeping the N{sub 2}/SiH{sub 4} gas mixture constant. Spectroscopic ellipsometry analysis in the ultraviolet-visible-near infrared and far infrared ranges, atomic force microscopy, and elastic recoil detection reveal strong variations in the optical properties (1.88{<=}n{<=}2.75, 10{sup -4}{<=}k{<=}5x10{sup -2} at 550 nm), optical gap (4.01 eV{<=}E{sub g}{<=}1.95 eV), microstructural characteristics (1.3 nm{<=}surface roughness{<=}8.3 nm), and chemical composition (0.47{<=}x{<=}1.35) of the coatings as a function of duty cycle. This behavior is interpreted in terms of radical concentration changes in the gas phase, as well as variation in the average ion bombardment energy at the film surface, leading to modifications of both chemical and physical mechanisms that sustain the film growth. Using the control of duty cycle, we fabricated two types of a-SiN{sub x}:H-based thin film devices, namely (i) a model Fabry-Perot optical filter deposited on plastic substrate and (ii) a superlattice structure displaying a photoluminescence signal four times higher than the reference single layer. These two examples of applications point out the main advantages of this pulsed rf PECVD process, in particular, low deposition temperature, reproducibility, versatility, and ease of use.

• OSTI ID: 20884726
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 100; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
CHEMICAL COMPOSITION
CHEMICAL VAPOR DEPOSITION
COATINGS
CRYSTAL GROWTH
ELLIPSOMETRY
INFRARED SPECTRA
ION BEAMS
MICROSTRUCTURE
OPTICAL FILTERS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
PLASMA
RADIOWAVE RADIATION
SILANES
SILICON ALLOYS
SUPERLATTICES
THIN FILMS
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA