Oxidation

In this chapter, we will talk about the “oxidation process,” which is practically the first step in semiconductor fabrication. In this oxidation process, which takes place after cleaning, the goal is to react silicon and oxygen to create a thin SiO2 layer. This process plays a particularly important role in semiconductor fabrication, because the quality of the SiO2 layer determines the performance of CMOS or NMOS transistors. Specifically, it is most important to have a uniform thickness of the SiO2 layer throughout the silicon wafer, i.e., the uniformity of the thickness distribution of the SiO2 layer is the most critical parameter. In this chapter, we will talk about the equipment used in the oxidation process, the chemical molecules used, and the differences between wet oxidation and dry oxidation.