PAS 5500 200 i-Line

A lithography stepper is a projection exposure tool used in semiconductor manufacturing. A lithography stepper transfers a patterned image from a reticle onto photoresist on a wafer by exposing one field at a time and then moving to the next field. A lithography stepper sits in the photolithography area of the fab and is used to define patterned layers for later etch, implant, deposition, or lift off related steps.

Photolithography takes place after wafer preparation and photoresist coating, and it is followed by development and pattern transfer. A stepper in this part of the line is used after the wafer has received the film stack to be patterned and before the exposed pattern is transferred by a downstream process such as etch or implant masking. Layer to layer alignment is a central function because the exposure must register to features formed in earlier process steps.

Lithography steppers are used to print repeating microelectronic patterns into photoresist on semiconductor wafers. Lithography steppers support pattern definition for active regions, interconnect related layers, contact related layers, and other process levels that require optical registration to existing wafer features. Lithography steppers of this class are also used in process development and legacy production flows where optical projection lithography remains part of the manufacturing sequence.