Interference lithography

Interference lithography is a technique for patterning regular arrays of fine features, without the use of complex optical systems or masks. The basic principle is the same as in interferometry or holography. An interference pattern between two coherent light waves is set up and recorded in a recording layer (photoresist). The technique is readily extendible to electron waves as well, as demonstrated by the practice of electron holography[1]. Spacings of a few nanometers are readily achieved using electron holograms.

The benefit of using interference lithography is the quick generation of dense features over a wide area. Hence, it is commonly used for testing photoresist processes for lithography echniques based on new wavelengths(e.g., EUV or 193 nm immersion).

The drawback of interference lithography is that it is limited to patterning arrayed features only. Hence, for drawing arbitrarily shaped patterns, other photolithography techniques are required.

References

1. R. E. Dunin-Borkowski et. al., Microsc. Res. Tech. vol. 64, pp. 390-402 (2004).