Every chip is made in a near-perfect vacuum, and MKS Instruments sold the tools that measure how near. Its pressure gauges and gas flow controllers sit inside the machines that etch and coat silicon wafers. Chip equipment makers bought them by the thousand. MKS had been making these instruments since the 1960s. When it went public in March 1999, the chip industry was climbing out of a slump and about to boom.

Gauges for Every Gas

MKS started in 1961 near Boston. Its early specialty was the capacitance manometer, a gauge that reads tiny pressures with great accuracy. As chipmaking grew, so did the need to control gases precisely inside sealed chambers. MKS built a wide line of gauges, valves, and flow controllers. Most of its sales went to semiconductor equipment makers such as Applied Materials. The rest went to other industries that worked in a vacuum.

From Gauges to Lasers

MKS priced its IPO at $14 a share in March 1999 and listed on Nasdaq as MKSI. Over the next 25 years it grew by buying other companies. It bought Newport, a laser and optics maker, in 2016 and Atotech, a chemicals company, in 2022. Those deals moved MKS well beyond chip tools. The company still trades on Nasdaq as MKSI, now under the name MKS Inc.

Cover: A Philosopher Shewing an Experiment on the Air Pump, Valentine Green. Art Institute of Chicago, public domain. Chosen for an experiment with the air pump (vacuum).