tailieunhanh - Novel Fabrication Methods for 2D Photonic Crystals in Silicon Slab Waveguides

A special method to manufacture metallic microstructures is SLM. It is one of the rare generative methods for metals and is normally taken into the list of rapid prototyping technologies. The technique is completely different than the abrasive techniques described so a base platformmade of the desiredmetalmaterial, a thin layer of a metal powder is distributed. A focused laser beam is ducted along the structure lines given by a 3DCADmodel,which is controlled by a the laser exposure, themetal powder ismelted, forming a welding bead. The first layer of welding beads forming a copy of the 3D CAD structure is generated. . | Invited Paper Novel Fabrication Methods for 2D Photonic Crystals in Silicon Slab Waveguides Dennis W. Prather Janusz Murakowski Sriram Venkataraman Yao Peng Anita Balcha Thomas Dillon and David Pustai The University of Delaware Department of Electrical and Computer Engineering 140 Evans Hall Newark DE 19716 Email dprather@ ABSTRACT In this paper we present the development of several new and novel fabrication methods for the realization of two-dimensional photonic crystal devices in silicon slab waveguides. We begin by presenting a process for the fabrication of high fill-factor devices in silicon-on-insulator wafers. Next we present a grayscale fabrication process for the realization of three-dimensional silicon structures such as tapered horn couplers. We then present the fabrication of suspended silicon slabs using a co-polymer process based on direct write electron beam lithography and silicon sputtering. And lastly we conclude by presenting an alternate method for realizing PhC devices in a silicon slab based on a combination of wet and dry etching processes in bulk silicon wafers. Keywords photonic crystal devices nano-fabrication silicon-on-insulator and slab waveguides 1. INTRODUCTION Since their introduction photonic crystal PhC devices have steadily received increased attention from the research community 1 . In terms of device geometries most references to PhC devices have come in the form of two-dimensional PhCs fabricated in slab waveguides with the majority of these being silicon slab waveguides 2-4 . A major reason for this is the ease with which PhCs can be fabricated using silicon-on-insulator SOI wafers which offer a streamlined process for creating suspended silicon slabs or asymmetric slab waveguides having a glass under layer. However despite the ease of fabricating PhCs in SOI wafers they remain significantly more expensive than their bulk silicon counterparts. As a result there is a motivation to develop silicon slab fabrication .