Semiconductor manufacturing equipment is the machines that a fab uses to build a chip on a silicon wafer, layer by layer. This page covers the two largest groups. Deposition machines lay down layers of material, sometimes only a few atoms thick. Etch machines remove material wherever the circuit pattern says it must go. Each machine can cost millions of dollars, and a large fab holds hundreds of them.
A chip is built from dozens of layers, and each layer follows the same cycle. First, deposition lays a thin film over the whole wafer. The film may be an insulator, such as silicon dioxide, or a metal, such as copper or tungsten. Second, lithography prints the circuit pattern for that layer onto a light-sensitive coating. It shines light through a mask, a plate that carries the pattern. Lithography is done by separate machines. Third, etching removes the film wherever the pattern has left it uncovered. Then the coating is cleaned off, and the next layer begins.
Most etching today is plasma etching. A plasma is a gas with so much energy that its atoms have lost electrons and carry an electric charge. Inside a sealed chamber, these charged particles strike the wafer and carry the uncovered film away, straight downwards. Some deposition is just as precise. One method, atomic layer deposition, adds one layer of atoms in each cycle. So the thickness of the film can be controlled to a fraction of a nanometre, a billionth of a metre.
Take, for example, an etch machine at a fab in Taiwan, cutting the tiny holes that connect two metal layers of a phone chip. Wafers arrive in a sealed box of 25, called a lot. A robot arm moves each wafer into a chamber. The machine follows a recipe, a list of gas flows, pressures, power levels and times. Here the etch lasts about 60 seconds. Hundreds of sensors record the chamber's conditions many times a second. Each hole must stop exactly on the metal below it. If it stops short, the connection fails. If it goes too deep, it damages the layer underneath. Over a week, the sensors show the chamber's pressure creeping up slightly, as deposits build up on its walls. The fab's software spots the trend, and the chamber is cleaned before any wafer is spoiled.
Why does this matter so much? A wafer that is etched wrongly cannot be repaired. One bad step can ruin hundreds of chips, and it lowers the yield, the share of chips that work. So the results of every machine are checked by wafer inspection and measurement, and the machines' sensor data goes to an industrial data platform for analysis.
The machines run on complex software, which controls each step and analyses the data it produces. The equipment makers run large engineering centres in Bengaluru and Chennai that write much of that software. The buyers are chip makers and each semiconductor foundry, mostly in Taiwan, South Korea and the United States. The new fab at Dholera in Gujarat, described on the page on semiconductor fabs in India, will need the same kinds of machine.