This photo shows a substage type IC-testing device with four motorized probing arms, making optimum use of the specimen chamber of the "FEI 986 FC". New sub-miniaturized motors made the very flat structure of the crosstables possible. Standard positioning accuracy is 1 µm under visual observation.

Pic.1: 4-station airlock-compatible prober module

Three motors are mounted to each one of the crosstables driving the prober needles in X, Y and Z from a small desktop controller, covering 14 mm x 14mm horizontally, and 5 mm in Z.The needles will be pre-aligned manually before evacuating the specimen chamber. Piezo touchdown works very gentle, far superior (10 nm) to any mechanical fine drive.

The whole probing device is inserted into the vacuum chamber by the standard airlock interchanger.

Movement Coverage and Docking in on the FIB Worktable

This probing module will work on chips held in place by small clips, as well as on packaged ICs. The prober module inserts through the airlock interchanger, like any one of the standard specimen holders. After arrival on the FIB worktable, the module docks in on 160 gold contacts, to connect to the motor and piezo voltages. Automatic contact is made at the same instant to four SMB high frequency connectors.

A "Dry Dock" workstation for the use of the prober module at air(under a light microscope, or for setup work)provides all operations and movements including signal handling, the same way as being done on the FIB worktable in the vacuumchamber.

The manipulator tips move up and down driven by a fine shift piezo element, controlled by a DC signal. This movement principle is magnitudes superior to any mechanical touchdown device. One of the main advantages is, that there is no lateral hysteresis at all (side shifting, when reversing the direction of the vertical piezo movement). The downward "coarse movement" is motorized, it can move extremely slowly. Many users find, that the motorized vertical movement is so fine, they almost never use the Z-Piezos. There is a "panic" button on the controller,lifting up all 4 needles together. In the relaxed status, the piezos are "short", this ensures that the needles move away from the specimen when a power failure occurs, so they will not accidently crash into the specimen.

Tiny screws hold the needles in small conical holder tips, at 45 degrees, straight, or at right angle to the holder arm. The signal cables are shielded, but very flexible. A large vacuum feedthrough flange with high frequency compatible plugs is in the shipment volume. Triax signal cables if required.

Controllers

Digital manual control, driving the sub-miniaturized motors of the manipulator crosstables; potentiometer for motor speed ranging from 1.5 mm down to as slow as about 0,2 µm per second. "Panic" button lifts all piezos when hit. There is a "communications window" for action control. The controller is a small desktop unit connected to a larger power electronics which may be placed behind the FIB or SEM. The software package "TouchDown" is now available.

Optional Software

The Kammrath & Weiss software package "TouchDown" provides many features for easier re-visiting previously memorized tip locations, and other systematic PC assisted work. Alternatively, the "Knights" software can be implemented. Detailed information upon request.

Further Products in this Field of Work

• "Electrostatic Beam Blanking" for pulses in the picoseconds range
• Wafer-Prober-Stage
• "Cryo-Stages" (Liquid Nitrogen or Helium)
• "Cryo-Modules" as substages (LN2). The cryo "Stages" can be combined with manipulators (fixed or detachable).
• Various other Prober Modules with one, two, three and more needles and piezo-driven manipulator stages in XY(Z)-"High Precision Probers" with 10 nm positioning resolution. Optional heating devices.