The influence of surface currents on pattern-dependent charging and notching
Surface charge dissipation on insulator surfaces can reduce local charging potentials thereby preventing ion trajectory deflection at the bottom of trenches that leads to lateral sidewall etching (notching). We perform detailed Monte Carlo simulations of pattern-dependent charging during etching in high-density plasmas with the maximum sustainable surface electric field as a parameter. Significant notching occurs for a threshold electric field as low as 0.5 MV/cm or 50 V/µm, which is reasonable for the surface of good insulators. The results support pattern-dependent charging as the leading cause of notching and suggest that the problem will disappear as trench widths are reduced.
Additional Information© 1998 American Institute of Physics. (Received 23 March 1998; accepted 14 April 1998) This work was supported by a NSF-Career Award and a Camille Dreyfus Teacher-Scholar Award awarded to K.P.G.
Published - HWAjap98b.pdf