Chuck Cleaning Wafers (CCW)
An Entegris chuck cleaning wafer is a silicon wafer with a flat, engineered polymer coating. It runs through the tool like a production wafer, polymer side down. The polymer conforms to the chuck surface, including grooves and pins, and particles stick to it and come out with the wafer. The chamber stays closed, there’s no hardware to change, and the tool is usually back in production within minutes.
Where it’s used
- Dry etch (electrostatic chucks). Particles under the wafer cause helium backside leaks and poor temperature control. Entegris quotes a few minutes to recover against more than 8 hours for a wet clean.
- PVD and other deposition (electrostatic chucks). Particles cause backside pressure faults and film non-uniformity. A few minutes against more than 12 hours.
- Lithography (vacuum chucks). A particle under the wafer causes a hot spot and a focus defect. A few minutes against more than an hour.
- Wafer probers and metrology (vacuum chucks). Particles carried in on wafer backsides tilt the wafer against the probe card and can damage the card. A cleaning wafer clears the chuck without stopping the prober to open it, which matters most when the chuck is running hot or cold.
Wafer types and sizes
- Laminated wafers on 75 mm, 100 mm and 150 mm substrates, in flat and notch versions and with different levels of tack. A high-temperature version is available.
- Spin-coated wafers on 200 mm and 300 mm substrates, including PM-PLUS for lithography chucks and a high-temperature SC4 coating.
Other sizes and special formats are made to order.
Reuse
Each wafer is designed for many cleaning cycles. Between uses, the debris it has collected is lifted off with particle removal film (PRF) and a hand-held contact roller, with the wafer held on a vacuum chuck. We supply the film, rollers and a 200 mm vacuum chuck with adaptor.
Choosing a wafer
Tell us the tool and chuck type (electrostatic or vacuum), the wafer size and whether it uses a flat or a notch, the chuck temperature, and the fault you’re seeing. If you already use an Entegris or ITS chuck cleaning wafer, the part number is enough. For background on where these wafers fit, see our chuck cleaning wafers page.
From SiSTEM
SiSTEM supplies Entegris chuck cleaning wafers in the UK and Ireland. We hold the most-used sizes and particle removal film in stock in the UK.
