MIT Advances E-Beam Lithography for Chips

Researchers at MIT consider e-beam lithography as a potential future candidate for semiconductor mass production.

It is unclear how far in the future, as the current immersion lithography technology has been much more stubborn than we originally thought a decade ago. Companies such as Intel, have successfully pushed out the adoption of the extremely expensive transition to extreme ultraviolet lithography (EUV) so far.

MIT researchers now believe that e-beam lithography, which is commonly used for prototyping and is currently a slow and low-volume production process for semiconductors, could be an option for chip manufacturers as the technology can be scaled down to structures of 9 nm. Compared to e-beam lithography, traditional photolithography uses light that shines through the entire surface of a mask at once. The e-beam uses electrons that scans across the surface of the resist (a material that covers each layer of a chip) on a row-by-row basis.

The MIT researchers said that they were able to increase the efficiency of e-beam lithography by using a thinner mask, which requires less energy per beam and enables a higher number of parallel electron beams to accelerate the production process. They also said they used a common table salt solution to "develop the resist, hardening the regions that received slightly more electrons but not those that received slightly less."

There is doubt that the MIT approach will find its way into production. One manufacturer of lithography systems, Mapper, said that the presented system was "a little bit too sensitive."