Introduction

Fundamental to the area of nanotechnology is the ability to modify surfaces. There are many methods available to researchers to achieve surface modification over large areas but there are limited choices for small samples or sections of samples. The main method for small sample manipulation is via focused ion beams (FIB). These devices enable the user to define complex patterns covering hundreds of square micrometers all the way down to submicrometer feature formation.

FIB enables various materials to be deposited such as conductors, insulators and carbon based materials. FIB also enables users to etch materials selectively. FIB induced deposition and etching has been widely used in the field of mask repair, circuit modification, formation of contacts in semiconductors, atomic force microscope (AFM) tip fabrication, maskless lithography, and TEM sample preparation.

In this chapter, the materials of deposition, the basic concepts of focused ion beam induced deposition and etching, their parameters, and application examples will be introduced. The material presented will mostly draw from work with Ga+ ion beams but other ion sources will also exhibit similar behavior with the addition of gas.

Gas assisted focused ion beam etching

The wide use of FIB systems as micro-machining tools stems from their ability to precisely mill away material from a localized area. This may be done to expose buried structures for failure analysis, as in the semiconductor field, or to create free standing structures for nanotechnology.