Obscura’s Blog

1.0 Introduction
1.1 Background of study

In this project, the optical waveguide will be fabricated using a silicon wafer. Some of the processes such as oxidation, photolithography and etching method must be done.
Oxidation is the most important step in fabrication. These include thermal oxidation, electrochemical anodization and plasma-enhanced chemical vapor deposition (PECVD) [2].
Photolithography is a process of transferring patterns of a geometric shape on a mask to a thin layer photosensitive material (photoresist) covering the surface on a semiconductor wafer [2].
Etching is a process to remove the unmasked portions of layer. Etching process can be divided to dry etching and wet etching. Wet etching is used extensively in semiconductor processing. It is suitable for blanket etches of polysilicon, oxide, nitride, metals and III-V compounds[2]. Dry Etching refers to the removal of material, typically a masked pattern of semiconductor material, by exposing the material to a bombardment of ions (usually plasma of reactive gases such as fluorocarbons, oxygen, chlorine, and boron trichloride; sometimes with addition of nitrogen, argon, helium and other gases) that dislodge portions of the material from the exposed surface. Unlike with many (but not all, see isotropic etching) of the wet chemical etchants used in wet etching, the dry etching process typically etches directionally or anisotropically [2].

1.2 Problem statement

The waveguide will be designed using Rsoft software. According to the design, the waveguide will be fabricated in UTHM clean room.

1.3 Objectives

The objectives of the project are to design and fabricate the silica optical waveguide. To fabricate the waveguide, the various type of waveguide needs to be designed. The design must have a function to guide the optical wave in single mode. After that, all waveguides will be tested in Rsoft software to see their performance.

1.4 Scope of project

• Silicon material or silicon wafer will be used. Silicon is ideally suited for such components because of its low production cost and well-established processing technologies that have been developed by the microelectronics industry [5].
• Rsoft software will be used to design the structure of the waveguide and also to simulate the waveguide in single mode optical fiber.
• The fabrication techniques will be studied in UTHM clean room. The fabrications process must do in area without the dust particles [2].