As explained in Chapter 3, nanolithography involves the transfer of a nano-sized pattern onto a material, which is then processed in line with that pattern. Particularly in the field of semiconductor manufacturing, nanolithography is one of the most promising next-generation technologies. In Near-field photolithography, patterns of tiny holes or slits of 100 nm or less are created on a metallic film impenetrable by light, and then light is applied. The only light that gets through the holes or slits is near-field light, resulting in the transfer of the pattern of holes or slits in the metallic film to the material on the underside.

Canon is developing near-field mask lithography processes that combine photomask production technology that uses thin-film base material to achieve tight, gap-less contact between the photomask and photoresist, and technology for the high quantity, uniform creation of the perforation patterns that give rise to near-field light. It has already succeeded in creating patterns using near-field light made up of components no wider than 20 nm, which is less than one tenth the wavelength of light (see "Near-Field Optical Technologies," Tackling Next Generation Technologies).

Boasting various advantages over other methods, including the fact that it enables processing to resolutions of the order of tens of nanometers without the need for large-scale equipment, this near-field mask lithography technology holds out tremendous promise for the next generation of exposure equipment, which will be expected to deliver 20 nm-sized resolution.