Peter H. McMurry, Associate Fellow

Modeling of Particle Transport in High-Density Plasma Chemical Vapor Deposition Tools

This research group created models to help avoid particle contamination in the manufacture of semiconductors. In recent years, the focus of particle contamination in production of semiconductor devices has shifted from the clean room to processing equipment and toward smaller particles. For example, it is predicted that by the year 2005 particles down to 0.050 µm, and perhaps as small as 0.015 µm, will be critical to the yield of 1Gbit Dynamic Random Access Memory computer chips. Such ultrafine particles are typically produced by nucleation in the gas phase. The research group’s main objective was to develop computational models to predict particle transport generated by nucleation in high-density plasma chemical vapor desposition tools.

During plasma processes, particles are charged negatively due to higher electron flux and trapped inside the plasma electrostatically. The purpose of this work was to predict the particle trajectory after the plasma is turned off. The flow velocity and temperature field were obtained first by using fluent. Then, the particle trajectories were calculated by simulating a discrete second phase in a Lagrangian frame of reference.

The results of this modeling work will be compared to those of experimental work that uses transmission electron microscopy. The combined results will improve the understanding of particulate contamination during semiconductor fabrication and will eventually make it possible to develop novel strategies to achieve defect-free manufacturing of semiconductor devices.

Research Group

Hiromu Sakurai, Research Associate