As semiconductor feature sizes shrink, manufacturers need a light touch — and at the right wavelength. A look at three areas — lithography, metrology and assembly — shows how photonics-based innovations are tackling some of the semiconductor industry’s most pressing problems.

Steppers are among the most critical tools used for semiconductor manufacturing and are at the heart of the photolithographic process, which transfers the features that are on a mask onto the photoresist material on a wafer. Subsequent processing reproduces that transferred layout in layers of conductors and insulators that eventually comprise a functioning integrated circuit. Today, state-of-the-art features are as small as 65 nm. Soon, they will be 45 nm, and the generation beyond that, 32 nm. The latter two scales are several years away, although the equipment needed for them is being rolled out now...