Reactive ion etching
Reactive Ion Etching (RIE) is a high resolution mechanism for etching materials. Samples are first masked by one of many patterning processes. They are then placed into a vacuum chamber. Gases are introduced into the chamber and then activated by Rf or microwave power to create a plasma. This plasma consists of a wide variety of reactive species, ions, and electrons. A negative DC bias is induced at the substrate by the free electrons. This bias accelerates ions in the plasma perpendicular to the sample surface. This provides a directional physical motivating force to the etch. Generally some form of passivating component is incorporated such that the etch proceeds only where energetic ions strike the surface. A well tuned etch can be very anisotropic compared to wet etches which are typically isotropic.
RIE is a key enabling semiconductor technology allowing IC processes to continue to approach the range of a few nanometers. This same technology may be used as a machining process for nano and micro scale devices. As such, RIE is also key enabling technology for MEMS and nanofabrication.
Technology Overview/Workshop Presentation
Reactive-ion etching (RIE) is an etching technology used in microfabrication. It uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated under low pressure (vacuum) by an electromagnetic field. High-energy ions from the plasma attack the wafer surface and react with it.