What is FEBIP?

FEBIP stands for Focused Electron Beam Induced Processing. It is a micro- or nanofabrication technique which can be used for deposition or etching of material and has many names: 

As the most general description, we have chosen FEBIP.

The basic principle of FEBIP can shortly be described as follows. In a high vacuum chamber, an electron beam is focused on a surface. A gas (generally called the precursor gas) is introduced into the vacuum chamber and the precursor molecules adsorb on the substrate. Under the influence of the electron beam, the precursor molecules are dissociated into volatile and non-volatile components. This beam induced reaction occurs only locally, at or around the irradiated area.

Fig. 1. Electron beam induced deposition (EBID). (Courtesy of I. Utke and W. van Dorp)
Fig. 2. Electron beam induced etching (EBIE). (Courtesy of I. Utke and W. van Dorp)

Depending on the type of precursor, the non-volatile components stick to the substrate and form a deposit (in the case of EBID, Fig. 1) or react with the substrate and form volatile species (in the case of EBIE, Fig. 2). Hence, a structure is grown or the substrate is etched. By moving the electron beam, 2D and 3D patterns can be transferred onto or into the substrate. The dimensions of the final structure depend mainly on the electron beam that is used, and can vary from hundreds of micrometers down to a single nanometer. The processes that occur at and around the irradiated area are very complex. Reactions at the surface (between substrate and precursor molecules) and electron beam induced effects (electron scattering, dissociation, heating, charging) occur simultaneously and only locally, making it a challenge to discover the governing mechanisms.

The advantage of this technique is that materials are patterned and deposited/etched simultaneously, making it a one-step technique. Since it is maskless and resistless, the method allows the freedom to choose any substrate material and geometry (planar and non-planar). The disadvantage of the method up to this moment is the low purity of deposits and the low throughput.


Fig. 3. The complexity of the FEBIP process is reflected by the different fields of expertise that it relates to. (Courtesy of C. Hagen)

A field closely related to FEBIP is IBIP (Ion Beam Induced Processing), also known as IBID (Ion Beam Induced Deposition). Ion beams can be used in a similar way as electron beams for etching, deposition and imaging, but, in addition, can also physically sputter materials. For more information, you can, for instance, visit the European Focused Ion Beam Users Group (EFUG) webpage at www.imec.be/efug/.