research

The actual circuit fabrication process is comprised of several  sequential steps. Each step may be repeated any number of times and each repetition adds a single layer to the circuit. The steps involved are:

• Deposit or grow a thin film on the surface of the wafer (Epitaxy)
• Transfer the circuit pattern to the film (Photolithography)
• Use the pattern to remove selected areas of the film (Etching)
• Process the exposed areas of the wafer 

Photolithography: The word lithography simply refers to a printing process involving pattern transfer to a plane or flat surface. The designation of "photo" lithography, and more specifically "micro" lithography, is used primarily to describe the process required to pattern submicron features on a wafer surface in semiconductor processing. Photolithography is the most critical steps in semiconductor processing and is the heart of the modern day integrated circuit. Technically photolithography is the process by which a pattern is transferred from a mask or recticle to the wafer surface.

Etching: It is the process of removing unwanted materials from the wafer surface. There are two types of etching: wet and dry (or plasma). Until recently, wet etching techniques have been the mainstay of pattern delineation methods. However reproducible and controllable transfer (etching) of patterns in the 1-2 µm range is difficult if not impossible using the conventional "wet" etching. As a result considerable interest in the "dry" etching techniques has developed. Specifically, plasma assisted etch processes are attractive because of their unique capabilities.

My research work is divided into two parts. The first part deals with the development of photoresist on SiC. I was responsible for developing the photo process on new semiconductor equipments that were brought in. The second part deals with using photoresist as an etch mask for SiC.
details