Plasma processes such as reactive ion etching (RIE) and plasma enhanced chemical vapor deposition (PECVD) constitute a large and essential part of semiconductor manufacturing processes today. As the dimensions of electric devices and circuits fabricated on a semiconductor chip surface decrease, the development of plasma processes with more precise controllability is increasingly needed. For the development of such processes, a better understanding of plasma-surface interactions under various process conditions is required. Recently several research groups have examined surface reaction mechanisms during plasma processing by using molecular dynamics (MD) simulations and compared the numerical results with experimental observations. It has been demonstrated that such MD simulations can provide useful, and sometimes quantitatively reliable, information on surface reaction mechanisms and process characteristics. To further extend the capability of MD simulations to examine more different processes that are widely used in the semiconductor industry, the author and his collaborators have developed classical interatomic potential functions suitable for MD simulations of Si/SiO2 selective etching by halogens and fluorocarbons and of organic polymer etching by hydrogen/nitrogen plasmas, using potential data obtained from ab initio quantum mechanical calculations. Using these functions, we have performed MD simulations for various RIE processes in order to understand the surface chemical reactions caused by plasma-surface interactions during the processes. In this presentation, we shall review recent results of our MD simulations and related experimental data (mostly those of well-controlled beam etching experiments) obtained by various authors.