This thesis presents the micro-fabrication process of a Long Range Surface Plasmon Polariton (LRSPP) biosensor device. The fabrication process was modified in two aspects which include adding a channel etch stop layer to improve the accuracy and uniformity of channels in the device and replacing the photoresist etching mask by an Al etching mask to avoid the thermal cracking. The optical performance of the fabricated chips shows that the biosensor has a 5.03dB/mm attenuation loss and has a 0.10dB response for a monolayer of BSA on Au waveguides. CYTOP bonding process was introduced in the fabrication of the device that incorporates a glass cover. A glass wafer was successfully bonded to a silicon wafer by CYTOP bonding process to seal the channels, which ensured an isolated testing environment for the biochemical fluid.iii

The authors report the fabrication of long-range surface plasmon polariton biosensors consisting of thin narrow Au stripes embedded in a low refractive index fluoropolymer with etched fluidic channels. The fabrication process incorporates a sacrificial SiO2 channel etch stop layer to avoid waveguide damage and prevent channel over-etching, and an Al etch mask to minimize thermal cracking of the fluoropolymer during channel etching. Process details are reported along with fabrication results, and the optical and biosensing performance of the fabricated devices are demonstrated. The biosensors were tested for bulk sensitivity and bovine serum albumin (BSA) protein adsorption producing notable changes for solutions with different refractive indices (increment of 2 × 10−3) and a change in insertion loss of 0.1 dB as a monolayer of BSA forms on the device.