Several lithographic techniques are used for patterning in the nanoscale region. Extreme ultraviolet lithography (EUVL) is an emerging contender for the replacement of optical photolithography in the production of computer chips.
Extreme Ultraviolet Lithography (EUVL)
Extreme Ultraviolet Lithography (EUVL) is very similar to standard photolithography but uses intense beams of ultraviolet light reflected from a circuit design pattern, or mask, to burn the pattern into a silicon wafer.
Figure 1. Simple schematic diagram of EUVL apparatus
Unlike photolithography that uses a system of lenses to focus light, in EUVL extreme ultraviolet light is reflected through a series of mirrors. This occurs in a vacuum as extreme ultraviolet light can be absorbed by air. The extreme ultraviolet light used in the process comes from a plasma created when a laser interacts with a beam of xenon gas clusters expanding at supersonic speeds.
The development of EUVL is targeted directly at enabling the production of the next generation in computer chips.
Building mirrors with sufficient precision is the current limiting factor in EUVL but once this problem is overcome resolutions below 30nm are expected.