Photonics Will Assist Next Lithography Tool

Aaron J. Hand, Senior Editor/Technology

Surely someday will find an end to Moore's Law, which says the number of transistors on a semiconductor chip will double every 18 months. Pundits have been predicting an end to this frenzied advancement in circuit density for some time, but progress shows no signs of slowing.
Continuing advances in lithography technologies have been vital to keeping chip architectures on this successful path, with optical lithography producing commercial semiconductors with feature sizes as small as 250 nm. Although optical lithography continues to outlive its obituaries year after year, it is certainly reaching its limits. It is expected to support one or two more generations to produce 180- and 130-nm chips, but the industry has been working to come up with the lithography technique that will take it further into the miniaturization future.
Lithography is by far the most critical step in the semiconductor manufacturing process, but it is also the most expensive. Despite the fact that chip makers are divided on which technique should be tapped as the postoptical lithography method of choice, they will have to come together to reach a decision on the best tool before long. The industry cannot afford to support more than one method.
Whatever the decision, a move past optical lithography by no means will see an end to the use of photonics technology in the lithographic process. Light-based devices will continue to support this vital step in semiconductor manufacturing.