Strasbaugh 6EC CMP system

Where the 6EC fits

Strasbaugh, a US maker of polishing and grinding tools, designed the 6EC as a single-wafer planariser for research and development. A used Strasbaugh 6EC suits a university cleanroom or R&D lab that needs to polish oxide, polysilicon or other films on 100 or 150 mm wafers and pieces, and that changes processes often. One wafer, one platen, one carrier: the simplicity is what makes it a good teaching and development tool.

Compared with a production platform such as the Applied Materials Mirra, the 6EC trades throughput for flexibility and a far smaller footprint. For bulk thinning or odd-shaped samples, a lapping system from our wet processing and CMP category may serve you better.

Common configurations

Most 6EC tools are set up with interchangeable platens, so a lab can keep one platen per pad type or process, plus a platen kept for lapping. The carrier and retaining ring set the wafer size; labs that work with both 100 and 150 mm keep a carrier for each. Pad conditioning is often in situ, which keeps removal rates steadier through a run.

How the tool was configured determines its value. Two or three dedicated platens with matching carriers are worth more to a research lab than a bare machine.

When removal rate drifts

On a shared 6EC, falling or uneven removal rate usually traces to consumables rather than the machine: a glazed pad, a worn conditioner disk or a carrier film that has lost its compliance. We check those first and log pad hours, because a pad and disk change often restores the rate. If the drift persists after that, the cause is more likely a downforce or drive fault, which calibration and repair will find.

What we inspect

• Carrier and gimbal. Wear, vacuum and backpressure function, retaining ring condition and how the carrier sits on the pad.
• Downforce. Whether the applied force matches the set value across the range.
• Platen drive and carrier spindle. Speed accuracy, bearing noise and vibration.
• Pad conditioner. Arm sweep, downforce and disk condition.
• Slurry and water delivery. Pumps, tubing and nozzles, including dried slurry in lines.
• Splash guard, drain and enclosure. Corrosion and leaks around the platen.

Refurbishment, calibration and training

Refurbishment covers new seals, bearings and tubing where needed, a cleaned and requalified slurry system, and a reset of the carrier. The most important step is calibration of downforce, platen speed and carrier speed, because removal rate depends directly on them. A Certified tool is run on blanket oxide wafers, and we report removal rate and uniformity.

CMP results depend on the operator as much as on the tool. Our operator training covers pad break-in and conditioning, slurry handling, post-polish cleaning and the logbook habits that make a shared CMP tool reproducible.

Facilities

Depends on configuration; we confirm the list for each unit.

• Power, voltage and phases depending on configuration
• DI water for rinsing and pad conditioning
• Compressed dry air and vacuum for the carrier
• Slurry supply, usually from bottles with a dispense pump
• Drain to a slurry-tolerant waste line
• Local exhaust for the polishing area

Buying advice

Ask which platens, carriers and conditioners come with the tool, and what it last polished. Metal slurries leave residues that need extra cleaning. For any tool of this age, plan spare parts early; our article on keeping legacy tools running describes how.