Modeling of low temperature plasma for FOUP cleaning*

The contamination control in the processing stages in semiconductor industry is a major issue for the microelectronics yield and performance, as well as for the development of new technologies in the area. This mainly concern the wafer carrier boxes (FOUP), which typically provide environmental isolation, clean and secure wafer transport. However, molecule or wall contamination inside the carrier box, can strongly affects the production processes. The goal of this research is to find an efficient solution for decontamination of the FOUP by generating an uniform low temperature plasma inside the box. Various types of plasma are considered with the main task of cleaning using the plasma fluxes directed to the walls and in the same time not damaging the surfaces. In order to apply and test different types of plasma we make use of numerical modeling. The first studied type of plasma is a capacitive RF plasma generated inside a closed box. A time dependent 2 dimensional multi-fluid model is constructed in order to study the plasma behavior and plasma properties. The model is applied to a simplified 2D geometry with pure Ar gas. The influence of various parameters are studied and preliminary results are presented.