Fabrication of array waveguide gratings (AWGS) for Multiplexers/Demultiplexers (MUX/DEMUX) application

Abstract

In this dissertation, the fabrication process of Arrayed Waveguide Gratings (AWGs) for Passive Optical Network (PON)implementation is presented. The study is important to the fabrication of AWGs as the fabrication tools are unique and need to be optimized. The study is also focuses on the metal masking process for the fabrication of a quality AWGs patterning process. Throughout this project, optimization has been carried out for direct-current (DC) planar magnetron sputtering of Cr, photolithography, and wet etching of Cr. The optimizations for the Cr metal mask are masking thickness, critical dimension (CD), side wall angle (SWA), and surface roughness. After the optimization process, we succeed to increase the patterning yield from 40% up to 100%. The critical dimension was also being reduced to the range of 0.4 – 0.8μm for 7μm width and 350nm thick Crpattern. The SWA of the photoresist (PR) was improved from 35° to 19°. Due to the wet etching properties, the surface roughness of the Cr pattern did not seem to be improved in this project.