ABSTRACT
This chapter introduces some ideas basic to understanding particles. It explains some phenomena important to the particle problems of the microelectronics industry and at a level commensurate. A particle is a small piece of material that is larger than a cluster of a few molecules, but small enough to remain suspended in a fluid for a time. It has the same physical properties as the bulk material of which it is a piece. When particles are suspended in a gas, the result is an aerosol. If all particles in an aerosol are the same size, the aerosol is said to be monodisperse. The most important property of an aerosol is its particle concentration. Concentration can be expressed in different ways. The forces of primary importance to determining the characteristics of particles in the microelectronics industry are drag force, gravitational force, inertial force, diffusion, electrostatic forces, and adhesion forces.
