Lithography

There are several different ways of creating nanodots. Lithographic methods such as those used by Cowburn et al. (1999a), Li et al. (2002) and discussed in chapter 3, although successful, are limited in the grain size they can produce; in photolithography the wavelength of light used in the fabrication process effectively limits the dot size to those above $0.4\mu$m, and electron beam lithography is still a prohibitively expensive process.