Plasma treatment of porous SiN{sub x}:H films for the fabrication of porous-dense multilayer optical filters with tailored interfaces

Journal Article · Thu Jun 01 04:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2202692· OSTI ID:20795841

Vernhes, R; Amassian, A; 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)

Porous and dense silicon nitride films with low (1.58) and high (1.88) refractive indices were prepared by using successively microwave and radio frequency (rf) plasma-enhanced chemical vapor deposition. Surface treatments were performed on porous layers using argon and nitrogen rf plasmas in order to densify and flatten their surface, and hence to obtain an abrupt transition between porous and dense films. The processes during deposition and interface treatment were studied by in situ real-time spectroscopic ellipsometry as well as by other characterization techniques. We show that besides the densification effect, preferential sputtering and annealing phenomena occur during plasma treatments at high bias (|V{sub B}{sup treat}|>400 V), leading to silicon enrichment at the film surface and chemical stabilization of the film bulk. Using atomic force microscopy, we observed a significant reduction of the thickness of the surface roughness layer after treatment for single layers ({approx_equal}70% reduction) and multilayer stacks ({approx_equal}60% reduction). Porous-dense Fabry-Perot filters were fabricated using this approach that led to both enhanced optical performance due to minimized interface thickness and improved environmental stability.

• OSTI ID: 20795841
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 99; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
ARGON
ATOMIC FORCE MICROSCOPY
CHEMICAL VAPOR DEPOSITION
ELLIPSOMETRY
HYDROGEN
MICROWAVE RADIATION
NITROGEN
OPTICAL FILTERS
PLASMA
POROUS MATERIALS
RADIOWAVE RADIATION
REFRACTIVE INDEX
ROUGHNESS
SILICON
SILICON NITRIDES
SPUTTERING
SURFACE TREATMENTS
THICKNESS
THIN FILMS