ASML PAS 5500 i-line wafer stepper

Where a used PAS 5500 fits

The ASML PAS 5500 is a step-and-repeat wafer stepper platform. Its i-line versions expose at 365 nm through reduction optics, printing sub-micron features across a whole wafer with automatic alignment and wafer handling. Pilot lines, MEMS and power-device fabs, and university research fabs that have outgrown contact lithography buy used PAS 5500 steppers because they give production-grade overlay and throughput.

It is a big commitment. A stepper needs a controlled room, careful facilities, trained operators and someone who can keep it running. For groups patterning a few wafers a week, a laser writer is often a better match.

Budget for reticles as well as the tool. Each layer needs a 6 in reticle written by a mask shop, and because the pattern is drawn larger than it prints, the reticle is easier to write than a fine contact mask. Even so, every layer is a separate order with its own lead time. That cost hardly matters for a fixed process, but groups that change designs every week feel it quickly.

What we look at before you buy

Every PAS 5500 we assess gets a configuration and condition review:

• Model and lens: the exact model, the numerical aperture range of the lens and the illumination options, from the tool's records and nameplates.
• Light source: mercury lamp house, shutter and illuminator.
• Stage and interferometers: stage motion, laser interferometer function and error logs.
• Alignment system: alignment optics, marks recognised and stored calibration.
• Wafer and reticle handling: robot function, cassette stations and reticle library.
• Environmental chamber: temperature control and filtration.
• Computer and software: system disks, backups and the state of the control hardware.

Where the tool can be powered in its current fab, we observe a run and record overlay and focus data the owner can provide. Where it cannot, the tool is sold As-is with full photos and history.

Relocation is most of the job

For a stepper, how the tool is moved matters as much as its condition. The lens and stage must be secured, shock and tilt monitored in transit, and the environmental chamber reconnected exactly. We plan de-installation and crating and the move as one project, then requalify the tool at your site. Your room needs stable temperature, a suitable floor and the right utilities before the tool arrives.

Service and spare parts

Our maintenance work on PAS 5500 steppers covers handler repairs, lamp changes, alignment and focus calibration, and fault finding from error logs. Parts are sourced from used and third-party stock; we are independent of ASML and do not imply OEM support. Before you buy, we tell you which parts are hard to find for that model so you can plan spares.

Facilities

• Three-phase power, depending on configuration
• Process cooling water for the lamp and electronics
• Clean dry air and vacuum for handling and stage
• Exhaust for the lamp house
• A temperature-stable, low-vibration room under yellow light

Buying advice

Settle the wafer size first: changing a stepper between 150 mm and 200 mm is only practical when the handler and chuck parts exist. Our post on 150 mm versus 200 mm tools covers that decision. Then compare the lens specification with your smallest feature, and check the export classification for your country early. The lithography overview lists alternatives for smaller labs.