- For etch, PVD, lithography and prober chucks
- Clears particles without opening the chamber
- Laminated: 75, 100 and 150 mm
- Spin-coated: 200 and 300 mm
- High-temperature versions available
- Reusable, reconditioned with particle removal film
- Most-used sizes held in UK stock
Chuck Cleaning Wafers
Chuck cleaning wafers clean the chuck inside a semiconductor process tool without opening it. A wafer coated with a soft, tacky polymer runs through the tool polymer side down, and the particles on the chuck stick to the polymer and leave with it. They’re used on process tools such as etch, deposition and lithography systems, and on wafer probers.
Chuck cleaning wafers are made for chucks built into automated tools, where the chuck stays in place and the cleaning wafer runs through like a production wafer. The vacuum chucks on spin coaters and spin developers lift off to be wiped clean, and our spin coater chucks page covers those.
Why the chuck needs cleaning
Particles reach the chuck on wafer backsides and from flaking inside the chamber. On an electrostatic chuck in an etch or PVD tool, a particle stops the wafer sitting flat, so the helium backside cooling leaks and the tool faults. On a lithography vacuum chuck, the same particle lifts the wafer locally and causes a focus defect. On a prober, it tilts the wafer against the probe card.
The traditional fix is to vent the chamber and wet clean the chuck. That takes hours, from about an hour on a lithography tool to more than 12 hours on a PVD chamber, and the chamber then has to pump down and requalify. A chuck cleaning wafer usually clears the same fault in a few minutes.
How it’s used
The cleaning wafer goes in through the normal load port or cassette and runs a short recipe that chucks and dechucks it, then comes out with the debris on its polymer face. Most fabs keep one per tool type and use it when a fault appears, or as a routine step after maintenance. The wafer can be cleaned and used again.
Choosing a cleaning wafer
The wafer has to match the tool’s wafer size and its flat or notch, and the polymer has to suit the chuck temperature and type. Laminated wafers cover 75 mm to 150 mm and spin-coated wafers 200 mm and 300 mm. Our Entegris chuck cleaning wafers page lists the options. We supply them in the UK and Ireland and hold the most-used sizes in stock.