Stepper Exposure

Stepper Exposure A step wherein circuits are drawn onto a wafer by passing light through a mask. While the same term is used to refer to adjusting the amount of light that enters a shutter in a camera, the exposure in semiconductor processes refers to a step of selective irradiation of light. Stepper exposure is a step where light passes through a mask carrying a circuit pattern, causing a layer of light-sensitive photoresist on a wafer surface to form a circuit pattern. The mask is placed on a wafer and exposed to light, and the light transfers the circuit pattern from the mask onto the wafer. This process takes place in the exposure equipment called a stepper. A mask is placed in the stepper, which then transmits light through the mask onto a wafer coated with photoresist to create a microscopic image of the electronic circuit on the wafer.