UltraStep 1500

The UltraStep 1500 handles wafers with diameters from 2 to 6 inches. The machine includes a laser, a receiver, and an autoloader for wafer handling.^[3][1][2]

A wafer stepper uses a projection lens system to reduce and focus the image of a reticle onto a small area of the wafer. The wafer is mounted on a precision stage that steps the wafer to the next exposure location after each field is exposed.

The machine aligns the reticle and wafer using an optical alignment system, then exposes the photoresist with a controlled light source. The laser component likely serves as the exposure source, while the receiver may be part of the alignment or metrology system.

The UltraStep 1500 is used in the lithography step of semiconductor wafer fabrication. Before exposure, the wafer is coated with photoresist; after exposure, the wafer undergoes development to form patterned resist layers.

Lithography steppers are typically positioned in the fab after the photoresist coating track and before the developer module. The patterned wafer then proceeds to etch or other transfer processes.

Steppers of this class are used for critical layer patterning where alignment precision and resolution are required beyond the capability of mask aligners.