New materials deserve a lot of credit for helping miniaturize the computer chips that make our smartphones smart and keep our data centers humming. Hafnium-based dielectric materials, for example, are helping shrink transistors in Intel’s latest chips. Cobalt-containing organometallic thin films are protecting delicate chip features. But credit should also go to the high-purity cleaning and particle-removal chemicals that underpin the chip-making process. After every application of an exotic material to a silicon wafer, a meticulous cleaning step is needed to remove leftover particles and other unwanted gunk. While new chip fabrication materials get the headlines, ultra-high-purity cleaning chemicals are unsung heroes making them possible. They may not get respect, but these chemicals are profitable, and demand for them is growing. Manufacturers are investing in both new facilities and new technologies for making them as pure as possible so they don’t contribute unwanted gunk of their own. As they get