In semiconductor processing, electric chuck heaters are used to heat the surface of a chuck, which is a device that holds a wafer in place during processing. The chuck is typically made of aluminum or copper and is used to hold the wafer during the various processing steps, such as photolithography, etching, and deposition. The chuck is typically cooled to prevent thermal damage to the wafer during processing, but it must also be heated to maintain a consistent temperature and prevent thermal gradients across the wafer.
The electric chuck heater consists of a heating element, typically made of resistive wire, that is embedded in the chuck. When current is passed through the heating element, it generates heat, which is conducted through the chuck and heats the surface of the chuck. The temperature of the chuck is controlled by adjusting the current flowing through the heating element.
The use of electric chuck heaters in semiconductor processing is important for several reasons. First, it helps to maintain a consistent temperature across the wafer, which is important for maintaining process repeatability and yield. Second, it helps to prevent thermal gradients across the wafer, which can cause warping and other defects. Finally, it can help to prevent contamination of the wafer by preventing condensation on the chuck surface.