An Airlock Compatible IC Testing Substage

This "custom-made" prober module for the Micrion 9000 (9500) FIB is inserted through the narrow entrance port of the loadlock-chamber - this is why we nicknamed this line of instruments the "Pico Prober Modules".

After arrival on the worktable inside the FIB, it engages with a "Zero Insertion Force" connector, which closes 160 electrical contacts. The sub-stage shown in the large photo is equipped with four manipulators, each of them covering 14 mm x 14 mm x 5 mm.

These manipulators are driven by miniature stepper motors which provide a positioning accuracy of 1 µm (standard version) in each direction. As an option, the XYZ movement is equipped with integrated fine shift piezo actuators, improving the positioning resolution to 10 nanometers.

New, Taller "Loadlock Chamber"

The "kit" for this module also contains a new loadlock chamber (see below), which fits to the front door of the Micrion 9000 (9500). It replaces the standard loadlock, the only difference being, that the lid does not taper down toward the operator, and that there is adequate space to clip on the prober module prior to insertion. All standard Micrion wafer holders fit the new loadlock as usual.

Specimen mounting, setup and alignment work is done at air, using a "Dry Dock" Platform.

The "Dry Dock" is a duplication of the worktable of the FIB that makes all operations and setup at air easy. It is equipped with the same ZIF-connectors, so it can be run directly from the electronics controller. Therefore, the module can be used at air, for instance under a light (or laser scanning) microscope.

Controllers

Desktop controller, driving the sub-miniaturized motors of the manipulator crosstables, digital 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. The "TouchDown" Software makes computer operation very comfortable.

Manipulator Movement - Miniaturized Crosstables

The coverage of the needle movement is 20 mm x 20 mm x 5 mm, topped by 10 µm piezo fine shift in each direction.

The development of the whole "Pico Prober" series became possible, after designing the miniaturized XYZ-crosstables shown in this photo. Instead of 65 mm high, as earlier models were, it now stands just 20 mm tall.

This made other designs possible, such as airlock-interchangeable prober modules. Note the arm extending to the left. It is the touch alarm that indicates reaching the end of travel in XY. For Z there is also a built-in alarm. Fine touchdown is done 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 accidentally crash into the specimen.

The prober module will work on chips held in place by small clips, as well as on packaged ICs. The specimens are mounted to the FEI stage, independent from the probing device, therefore they can rotate freely. The probing arms are mechanically adjustable before pumpdown, to optimize their coverage.

Further Products in this Field of Work

• Fast Electrostatic Beam Blanking ( "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 more than two needles and piezo-driven manipulator stages in XY(Z) - "High Precision Probers" with 10 nanometers positioning resolution.