Refractive index properties of SiN thin films and fabrication of SiN optical waveguide

Abstract

SiN thin films having excellent surface morphology for the optical device application were synthesized using a plasma enhanced chemical vapor deposition (PECVD) method at low temperature (350 • C) using silane (SiH 4 ) and nitrogen (N 2 ). The effects of the SiH 4 /N 2 flow ratio, rf power and annealing on the SiN films were investigated. The optical and structural properties of SiN films were characterized using an ellipsometry, a fourier-transform infrared spectroscopy (FT-IR), and an atomic force microscope (AFM). The refractive index increased from 1.6 to 2.3 as the SiH 4 /N 2 ratio was increased from 0.17 to 1.67. The rms surface roughness decreased from 14.1 to 3.6Å after post-deposition annealing process performed at 800 • C for 1hr in an air ambient. We could fabricate straight waveguides based on a three layer structure and have no problems with step coverage.

Dynamical backaction in an ultrahigh-finesse fiber-based microcavity

“…We can numerically reproduce this modulation via the transfer matrix method [38]. The membrane stripe is simulated as a dielectric slab with a refractive index of n = 1.725 + (3.55 × 10 −5 )i (see Appendix A), in accordance with the values reported in the literature [39,40]. The shape and magnitude of both the linear and quadratic coupling agree well with the numerical simulations.…”

“…Figure 7(a) depicts the measured cavity linewidths with the sample inserted (blue circles) and simulations (black solid line) as a function of the membrane's position. To reproduce the measurement we need an imaginary part of the refractive index of Im(n) = 3.55×10 −5 , whichagrees to what has been reported in the literature for stoichiometric Si 3 N 4 (Ref [39,40]…”

A Review: Preparation, Performance, and Applications of Silicon Oxynitride Film

“…Adjustable refractive index means that the refractive index can be continuously tuned along the normal direction of the surface of the SiN x O y film by changing the proportion of the reaction gas [58]. In order to prepare graded-index SiN x O y film for applications in optical waveguide materials, gradient-index films, and anti-reflection films, researchers conducted extensive research on the refractive index-adjustable performance of SiN x O y film, such as the research on controlling the flow rate and ratio of reactive gas, reaction process, etc.…”

Stamp stress analysis with low temperature nanoimprint lithography

“…To save cost and time, it is necessary to study the LTNIL process by modeling and simulation. Kim et al used a viscoelastic model to simulate low temperature NIL with temperature range T g < T < T g + 40°C [10]. Song et al researched room temperature NIL by simulating different imprinting speeds and patterns [11].…”