ultraviolet lithography abbr., DUV; EUV (rus. литография, ультрафиолетовая otherwise глубокая ультрафиолетовая литография; экстремальная ультрафиолетовая литография) — nanotechnology of electronic circuits using lithography with exposure of the photoresist by deep ultra violet (DUV) or extreme ultra violet (EUV) radiation.

Description

Ultraviolet radiation with a wavelength of 248 nm (deep ultraviolet) allows using templates with a minimum width of conductors of 100 nm. The circuit layout is produced by ultraviolet radiation that passes through a mask and is focused by a system of lenses that reduces the pattern on the mask to the microscopic size of the circuit. A silicon wafer is moved under the lens system so that all microprocessors on the wafer are successively treated. Ultraviolet rays pass through the free spaces of the mask. Under their influence the positive photosensitive layer in the relevant area of the wafer becomes soluble and is removed with organic solvents. The maximum resolution achieved by DUV lithography is 50-60 nm.

Extreme ultraviolet radiation (EUV) with a wavelength of about 13.5 nm provides a nearly 20-fold decrease in the wavelength, as compared to the DUV, to a value corresponding to the layer thickness of several tens of atoms. EUV lithography makes it possible to print the lines up to 30 nm wide and form electronic components with the dimensions below 45 nm. EUV lithography uses systems of special convex mirrors that reduce and focus the image obtained after applying the mask. Such mirrors are nanoheterostructures containing up to 80 separate metal layers (each with thickness of about 12 atoms), therefore they do not absorb, but reflect the extreme ultraviolet radiation.

Illustrations

Microstructure containing 80 nm wide elements with spacing of 200 nm fabricated on a Si wafer usi

Microstructure containing 80 nm wide elements with spacing of 200 nm fabricated on a Si wafer using the lithography technique with UV radiation in the 248 nm wavelength ("blue ultraviolet").


Author

  • Gusev Alexander I.

Source

  1. Gusev A. I. Nanomaterials, Nanostructures, and Nanotechnologies (in Russian) // Fizmatlit, Moscow (2007) - 416 pp.

Contact us