Patent attributes
Methods, systems, and computer programs are presented for determining wear of a consumable part in a semiconductor processing apparatus. One chamber includes a reference part, a consumable part, a transfer arm for transferring the substrate into the chamber, a sensor on the transfer arm, and a controller. The reference part is not subject to wear during operation of the chamber, while the consumable part is subject to wear. The sensor is configured to measure a first distance from the sensor to a surface of the consumable part as the transfer arm travels near the consumable part, and the sensor is configured to measure a second distance from the sensor to a surface of the reference part as the transfer arm travels near the reference part. The controller determines the wear amount of the consumable part based on the first distance and the second distance.