<human>:  I have a question about semiconductor lithography. When you are printing a circuit pattern on a silicon wafer, what is the process called?
<bot>: The process is called photolithography. Photolithography is a process used to create a circuit pattern on a silicon wafer. The process involves exposing a light-sensitive chemical called photoresist to a light source. The light source is usually a laser, but it can also be a light emitting diode (LED). The light source is used to expose the photoresist, which is then developed to create a pattern. The pattern is then used to etch the silicon wafer.