Dust nucleation and growth in reactive ion etching discharges
- Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering
Particle contamination of wafers in plasma processing reactors is a continuing concern in the semiconductor fabrication community. For example, in Reactive Ion Etching discharges (RIEs), moderate ion fluxes and biases lead to a balance in electrostatic and ion-drag forces on large particles near the plasma-sheath boundaries, resulting in particles trapping above the substrate. For the same conditions, intermediate sized particles may be trapped near the peak in the plasma potential. Small particles behave more like large charged clusters and, under certain conditions, may have large fluxes onto the substrate. The rate of growth of these particles, as well as the transition between neutral and charged states, are therefore important in evaluating particle contamination. A 2-dimensional Monte Carlo simulation has been developed to address particle growth and transport in RIE discharges. They will present several strategies to prevent large particle growth and accumulation above the wafer. Particle size and density distributions also is presented for early times (10s ms) and late times (a few seconds) after discharge initiation to demonstrate the evolution of particle size distributions.
- Sponsoring Organization:
- Sandia National Labs., Albuquerque, NM (United States); National Science Foundation, Washington, DC (United States); Wisconsin Univ., Madison, WI (United States)
- OSTI ID:
- 419692
- Report Number(s):
- CONF-960634--
- Country of Publication:
- United States
- Language:
- English
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