A Review of Magnetron Etch Technology

Abstract
Magnetic confinement of a low pressure rf discharge is useful in generating high density plasmas with low sheath voltages at the bounding surfaces. Thus, substrates exposed to such plasmas receive large fluxes of low energy ions. Additionally, since source gas fragmentation is substantially higher than in conventional systems, the etching chemistry is also very different. The discussion will focus on designs in which the magnetic field is generally parallel to the substrate and highlight the physical properties of these configurations which lead to low impedance and high plasma density. Examples of etching characteristics in polymer and silicon etch chemistries will be given. In many cases, excellent uniformity, high etch rate, and very flexible profile control have been demonstrated; and magnetron systems have proven to be entirely appropriate for in situ wafer at a time processing applications. The future of these systems is very bright, although there are still a few unresolved issues, such as oxide etching which is selective to silicon. The nature of the problems, as well as potential solutions, will also be discussed in this presentation.