Future Trends in Microelectronics: From Nanophotonics to Sensors to Energy

SI₃N₄/SiO₂ Planar Photonic Structures Fabricated by Focused Ion Beam

L. A. M. Barea, F. Vallini, D. L. S. Figueira, A. Da Silva Filho, N. C. Frateschi

Device Research Laboratory, Applied Physics Dept. Gleb Wataghin, Univ. of Campinas–UNICAMP, 13083-970 Campinas, SP, Brazil

A. R. Vaz

Center for Semiconductor Components, University of Campinas–UNICAMP, 13083-870 Campinas, SP, Brazil

1.   Introduction

Micro-optical resonators are essential components in optical integrated systems, as they facilitate the selective capture, release, and storage of photons as well as interaction with matter and other photons. As an example, microdisks¹ and micro-rings^2,3 are elements that provide extremely long photon lifetimes that can be used for spectral filtering and for highly efficient nonlinear photon interactions.^4,5 The small volumes and the high photonic lifetime in micro-resonators are very important, for example, to enable four-wave mixing (FWM) with a single pumping frequency.⁶

However, coupling light to and from the micro-resonator is still achieved via hybrid integration, typically using tapered silica fibers.⁷ In this chapter, we present a new technique for the fabrication of structures with monolithically integrated resonators and planar tapered waveguides, all based on SiN_x/SiO₂ layers deposited on silicon.

We use an approach that combines nanofabrication techniques based on focused ion beam (FIB) milling and smoothing⁸ and conventional microfabrication techniques. We have fabricated ...