Ion Beam Etching

Summary

This chapter explores chemically assisted and chemical etching processes. Material can also be removed by pure physical sputtering. Ion beam etching (IBE) is an important technology for patterning of nonvolatile and chemically sensitive materials. The etching rate is a function of the ion flux, the sputtering yield, and the density of the material. The design of IBE grids with good ion flux and divergence uniformity is considered an art. Etching selectivities are generally low in IBE. IBE is prone to aspect ratio dependent etching because the transport of the sputtered species out of the features is a function of their aspect ratio. One class of applications that remains inaccessible for reactive ion etching is patterning of magnetic random access memory devices. To become more widely used, IBE chambers must be able to handle reactive background gases and reactive ions to introduce chemical effects.