Using ZYGO’s Large Aperture Systems to Maintain Two Independent Metrology Cavities

ZYGO^®’s horizontal-axis Large Aperture systems are designed to maintain two independent metrology cavities - a nominal interferometer aperture (4"), and a choice of one of four beam expander diameters (12", 18", 24" and 32").

When configured with the proper accessories, these systems can measure both surface form and transmitted wavefront quality.

The Large Aperture Systems comprise of:

Interferometer mainframe (Dynafiz™ or Verifire™)

Beam expander (available as 12", 18", 24" or 32" diameter)

MUX cube (switchable mirror assembly)

Reference optics – transmission and reference flats as needed based on the optical configuration

Phase measuring receptacle (for 12" and 18" systems; 24" and 32" utilize wavelength shifting mainframes and do not need a PMR)

Mounts – Mounts for the test optics and reference optics are available

The Large Aperture System parts can be purchased independently of the interferometer mainframe.

Verifire™ XL

The Verifire™ XL interferometer system is a stand-alone large aperture workstation for measuring flat surfaces up to 12” (300 mm) in diameter. Examples include front-surface reflectors, windows, and wafer chucks or semiconductor wafers.

With its downward-looking configuration, the system eliminates the need for special component holding fixtures in most conditions. The operator can just place a test part on the flat surface of the tilt/tip stage, and slide the entire stage under the measurement aperture.

The Verifire™ XL interferometer has a small footprint, thus requiring only a minimal area of valuable floor space in a production facility. All the requirements of the user are in-built, including the vibration isolation system. The transmission flat is also integrated and pre-aligned, and does not need any adjustments. This enhances throughput and simplifies operation.

ZYGO^®'s special QPSI™ acquisition technology is also incorporated. This helps to eliminate fringe “print through”, which in turn enables reliable high-precision measurements, even when there is vibration (frequently found in production environments).