Reducing aspect ratio dependent etch with direct current bias pulsing

Abstract

Embodiments of the present disclosure generally relate to a system used in a semiconductor device manufacturing process. More specifically, embodiments provided herein generally include apparatus and methods for synchronizing and controlling the delivery of an RF bias signal and a pulsed voltage waveform to one or more electrodes within a plasma processing chamber. The apparatus and methods disclosed herein can be useful to at least minimize or eliminate a microloading effect created while processing small dimension features that have differing densities across various regions of a substrate. The plasma processing methods and apparatus described herein are configured to improve the control of various characteristics of the generated plasma and control an ion energy distribution (IED) of the plasma generated ions that interact with a surface of a substrate during plasma processing. The ability to synchronize and control waveform characteristics of a voltage waveform bias established on a substrate during processing allows for an improved control of the generated plasma and process of forming, for example, high-aspect ratio features in the surface of the substrate by a reactive ion etching process. As a result, greater precision for plasma processing can be achieved, which is described herein in more detail.