David J. Haruch

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Cool Precision Semi Parts

Updated 2025-09-17

This is a collection of saved Ebay (and other sites like ebay) used parts listings. Annotations are speculation and are my own. All photos are obtained from public web-pages or public patent literature

Table of Contents

ASML

Yieldstar T200 - 2013 Vintage

Original Sources

Overlay metrology machines use special measuring microscopes (imaging or scatterometry) to take pictures of special marks made on wafers. Based on the pictures or signals from imaging the marks, the offset between special marks between layers can be measured (at sub-nanometer scale).

Balance mass video

The machines use a motion system (stage) to move the wafer with respect to the optics to take pictures of all the marks on a wafer at high throughput.

This ASML machine moves the wafer on X axis and the camera on the Y axis. This approach probably gives higher performance that a stacked XY stage layout assuming the camera is lightweight and compact.

The stages float on air bearings presumably preloaded by visible magnet arrays. Based on the porting holes the bearings appear to be an orifice or orifice/groove type. Magnetic preload allows for higher force density compared to a vacuum preloaded system. This enables stiff bearings and high servo bandwidth. The distintive mirror finished surfaces are required for air bearings to fly correctly (on a few micron film of air). There appear to be 3 horizontal bearings constraining Z, Rx, Ry DOFs and 2 vertical bearings constraining Rz and Y DOFs. Air bearings are also very clean (no particle or oil/grease droplet risks)

There is a balance mass system to eliminate optics excitation or stage crosstalk from motor reaction forces. The balance mass system also floats on air bearings. There are moving magnet trim motors and commutation encoders for the balance masses.

There are EDM cut flexures on a component perhaps for thermal relief or improved repeatability.

A pair of magnet tracks move the wafer stage along its remaining X DOF. Therefore the axis is moving coil. I would expect there to be a water cooling system to cool the motors. Visually these look like Tecnotion linear magnet tracks which have distinctive nickel plating on the back irons and black epoxy coated magnets

Overall the stage motion system appears capable of both high throughput and high repeatability due to all motion axes floating on air bearings.

KLA-TENCOR

Archer AIM 200 - 2007 Vintage

Source: https://caeonline.com/buy/mask-wafer-inspection/kla-tencor-archer-200-aim/9255571

KLA Archer machines are overlay metrology machines. The layout is a "C-Frame" much like a bridgeport mill but with an objective/optics/camera assembly instead of a milling spindle. Special marks made on wafers during the semiconductor manufacturing process are imaged to measure how well layers are aligned.

Stage and controller have ETEL branding. Appears to be a customized off-the-shelf stage

Stacked stage contruction using iron core linear motors and roller type linear guides. Label XYT. Stage structural material looks like aluminum. Overall nothing special and low cost (ETEL must take a healthy margin)

A high voltage electronics box and labels of "Z-PZT" likely mean there is peizo axis in the optics.

The stage and optics are mounted to large grey granite. The granite connects to steel weldment through passive isolation metal springs. There are visible magnets belonging to voice coil motors used to stop granite motion due to stage reaction forces. Compared to the 2013 ASML yieldstar machine above (with balance masses absorbing stage reaction forces) these voice coils and amplifiers likely add cost and they do not eliminate the excitation of the optics from stage reaction forces.