Particles and particle transport in ion implanters

The behavior of particles on wafers during implantation is analyzed and methods of eliminating particles are discussed. Particle transport is mainly aerodynamic and particles are held on wafers by electrostatic (and chemical) forces. By eliminating aerodynamic forces and decreasing electrostatic forces, particle count on wafers can be greatly diminished. In experiments reported here, the additional particle count per implantation was reduced to +- 4 particles per wafer using proper precautions. (orig.)