SemEquip Ion Source

SemEquip’s key technology is the innovative ion source which has been developed and is currently in productization. This source uses an alternative ionization process and specialized design to produce intense ion beams of N and P type clusters.

Ionization Process

The first innovation in the SemEquip ion source is the ionization process itself. Conventional ion sources used in ion implanters utilize intense plasmas to produce ions from the feed materials. These plasmas dissociate large molecules and increase the emittance of the resulting ion beam. The SemEquip ion source uses an alternative, soft ionization process which produces intense ion beams of large molecules like ClusterBoron^® without dissociation. In addition, the SemEquip source produces cluster ions from conventional feed materials, while conventional sources do not produce cluster ions.

Molecular Preservation

Since the ClusterIon^® ion source was developed with cluster implantation in mind, it is designed to produce cluster ion beams without dissociation of the cluster molecule. The ClusterBoron^® molecule, for example, is relatively fragile and it is not compatible with conventional ion sources. The soft ionization process, and careful source design, allow the ClusterIon^® source to produce ClusterBoron^® beams of unprecedented intensity and quality.

Cluster Formation

The SemEquip ion source design is unique in it’s ability to produce clusters from conventional feed materials. For example, arsine feed material (AsH₃) is introduced into the source and a beam containing a significant fraction of As₄ is produced.  No other ion source used for ion implantation is known to produce this cluster ion, and yet it has significant advantage for the formation of N-type USJs. The SemEquip source produces many clusters in this way, such as the tetramer of phosphorus (P₄). These clusters open a wide array of potential implant processes with low effective energies not previously practical with conventional technologies.

Beam Current

It is important to note that it is necessary to produce competitive currents of these alternative implant species.  Even in prototype form, the SemEquip ion source is producing production worthy beam currents of ClusterBoron^® and arsenic tetramer. We fully expect that our continued development will produce significantly higher currents of these and other species of interest. It is our goal to provide technology for the productive formation of USJs for all future generations of semiconductor technology.

Brightness and Emittance

A fundamental issue for some implanter designs is the brightness of the ion beam.  Brightness is a measure of the beams intensity per unit angle. A related measure is emittance, which is a parameter characterizing a beam’s angular divergence. The SemEquip ion source produces a beam of high divergence and low emittance. This capability is directly related to the ion source design and the soft ionization process used for ionization. The combination of good beam current intensity and low emittance produces beams with very high brightness. This feature is especially important for medium current implanters, where control of the beam characteristics are critical.