Monte Carlo modeling of the dc saddle field plasma: Discharge characteristics of N2 and SiH4

Enhancements in rates of ionization, dissociation, and current in the dc saddle field (DCSF) glow discharge are studied using the direct Monte Carlo method (DMCM). The DCSF consists of a planar semitransparent anode positioned between two planar cathodes, producing a symmetric electric field that serves to lengthen the path of electrons. Simulations of current versus anode transparency of a N2 discharge agree very well with experimental results reported previously. Numerical results of the DCSF SiH4 discharge are also presented. At typical operating conditions (600V, 5cm cathode-anode spacing, anode transparency of 0.8), DMCM predicts a significant increase in the dissociation rate at pressures below 100mTorr in comparison to the dc diode. In consideration of its use for plasma enhanced chemical vapor deposition, the efficiency with which the DCSF operates at low pressures makes it attractive for the production of thin films whose qualities are sensitive to gas phase reactions.