Microscopy doesn’t get much attention in the general tech press (although we’re used to seeing really cool pictures taken by scanning electron microscopes (SEMs), whether they’re FinFET cross-sections or nematodes up close).
But in a wafer production line, you need inspection to identify, for example, whether a mask has a defect that could cause yield loss. You can see such defects using different light wavelengths, but the folks at Lawrence Berkeley have remarked that the wavelength makes a big difference in how things look.
So logic would suggest that, if you are looking for issues that will affect EUV exposure, then you should look at the target using the same light: EUV. So they’ve announced a project to develop what they call “the worlds most advanced [EUV] microscope,” called SHARP (Semiconductor High-NA Actinic Reticle Review Project… really??)
Lest this sound like no big deal, it will take 1½ years and $4.1M to do. And there are numerous technical challenges that parallel those of their photolithographic brethren (although at least they don’t have to develop a high-volume production source of EUV photons…). Most materials absorb EUV light, so you can’t use glass lenses; you have to use mirrors. Bizarrely, the lenses are “only slightly wider than a single human hair,” with high quality images magnified by up to 2000x.
More details on the features they’re designing can be found in their release…