A study on reactive ion etching lag of a high aspect ratio contact hole in a magnetized inductively coupled plasma

Abstract

Reactive ion etching lag (RIE lag) characteristics of a high aspect ratio contact hole in a magnetized inductively coupled plasma (M-ICP) etcher were investigated. The dependence of RIE lag on various process parameters, such as neutral gas pressure, magnetic flux density, bias power, bias frequency, and source power were investigated. It was confirmed that RIE lag could be reduced by properly adjusting these variables. Furthermore, the application of a magnetic field to the ICP etcher was helpful to increase the oxide etch rate and oxide-to-amorphous carbon layer selectivity.