A common application in today’s fast paced semiconductor industry is measuring high frequencies in the RF/Microwave region (GHz). RF/Microwave measurements enable engineers to characterize both the linear and nonlinear behavior of devices, providing critical information such as the cutoff frequency of a filter and amplifier power output. RF/Microwave measurement applications can be difficult without the proper measurement equipment and further complicated if proper techniques are not used. The Micromanipulator Company has responded to the demands of RF/Microwave probing, offering a complete line of RF/Microwave probing stations and accessories designed to meet industry needs. In addition Micromanipulator probe stations are designed to support both low level DC and high frequency AC measurements on the same probe station.

Micromanipulator invented analytical probing in 1956 and was the first probe station manufacturer to offer a high frequency GHz probe, the popular model 44. Micromanipulator has complete RF/Microwave probing systems that are easy to use and capable of obtaining repeatable and consistent measurement data. Micromanipulator RF/Microwave probing systems are designed to painlessly interface to Network Analyzers and to provide an extremely stable station structure to reduce vibrations and increase probe and cable stability.

While Micromanipulator has a number of high frequency probes and probe holders it also offers the Picoprobe® line of RF/Microwave passive and active probes.

Micromanipulator High Frequency/Microwave Products

• Wide range of probe stations compatible with High Frequency/RF tests
• Wide range of ambient and thermal chucks with a built in calibration substrate holder
• Microwave manipulators and probe head link arms
• RF/Microwave probes
• Calibration substrate
• Cables
• Variety of shielding methods

Station choices
There are three options available from Micromanipulator when considering a probe station for RF/Microwave probing; manual, motorized and semi-automatic. Choosing between these stations is a matter of personal choice, budget and application. Most of Micromanipulator probe stations may be configured for RF/Microwave testing. All our probe stations have open designs that facilitate RF/Microwave cable routing and overall setup flexibility.

Micromanipulator recommends either the 4000 or 8000 series stations for RF/Microwave tests of 6/8" (150/200mm) wafers or the P300 series stations for 300mm wafers. Manual, motorized and semiautomatic versions are available. The 4060 stations are recommended when only basic testing is required; the 8060 stations are recommended when both RF/Microwave testing and low current/low noise tests are required.

All stations have rock solid four point platen support/lifts that mechanically isolate vibration. The large area platen accommodates a variety of probing setups, cabling and large RF/Microwave manipulators. The standard configuration provides the ability to smoothly raise and lower the probe station’s platen for probe touchdown and separation. Professionals appreciate the ability to see the DUT while at the same time protecting expensive RF/Microwave probes. In contrast, when the station chuck is allowed to move in Z, sample focus is lost and probe damage is far more likely because the distance between the probes and the point of contact is not visible. However, these probe stations are available with Z stage/chuck mount and drives should the user want to hold the platen rigid and raise and lower the chuck to meet the probes. Micromanipulator provides both alternatives.

Calibration Substrate Chuck
Micromanipulator offers a wide range of ambient and thermal chucks with integrated calibration substrate holders. These chucks are designed with two substrate holders placed on the side of the chuck body which provide flexibility in orienting calibration substrates. The substrate fixtures do not restrict stage movement and increase testing efficiency because calibrations can be conducted without removal of the DUT. The calibration substrate holders are mounted outside the heat shield ring on thermal chucks, thus the calibration substrate remains at a constant temperature even while the sample temperature changes.

Manipulators and Probe Head Link Arms
The RF/Microwave manipulators and probe head links supplied by Micromanipulator are another key element of an optimal RF/Microwave setup. The WAVE100 and WAVE200 manipulators feature anti-backlash, rectilinear XYZ axis controls for precise, anti-drift positioning. They are designed to probe pad sizes of > 2 microns.

The WAVE manipulators have a large base to damp probe vibration and provide a solid platform for the manipulator controls. The base comes in a number of versions to attach to a wide range of platen types. A combination vacuum and magnetic base is recommended. It combines the advantages of a magnetic holder which resists tipping when using heavy cables with advantages of a vacuum base which resists horizontal creep on the platen. The combination base provides an attachment to the platen associated with a mechanical lock-down but with the flexibility to position the manipulator anywhere on the platen. A standard vacuum base or magnetic base is also available.

The model WAVE100 and WAVE200 manipulators may be fitted with two versions of link arms to hold Picoprobe® Model 40 and above probe heads. These link arms have controls which provide 4° of probe rotation to adjust planarity and 4° of theta adjustment. Precise tip planarity and theta adjustments are critical to RF/Microwave applications to maintain probe contact with non-planar structures and precise tip placement. The model PLS-8000 link arm holds the probe head straight along the main axis of the arm and the model PLF-8000 holds the probe head at a right angle (90°).

RF/High Frequency Probes and Probe Heads
Micromanipulator offers a number of probes which may be used in tests over 1 GHz. The model 44RF passive probes are designed to operate between 700MHz and 5 GHz. Two point designs (G-S or S-G), and UMC or SMA cabling are available. For highest performance SMA cables are used. These probes are used with standard manipulators not the WAVE100/200 models.

Picoprobe® Probe Heads and Calibration Substrates
Micromanipulator offers the industry leading Picoprobe® RF/Microwave probes. Picoprobe® probes are available in passive (DC to 5GHz) or active (DC to 26 GHz) versions which fit in standard manipulators. Higher frequency probe heads (DC to 325GHz) are used with the WAVE100/200 manipulators and the PLS8000 or PLF8000 link arms.

Calibration Substrates
Calibration substrates enable the user to calibrate the complete RF/Microwave system (network analyzer + cabling + probes) to a known NIST standard. Micromanipulator offers GGB Industries complete line of calibration substrates. Each GGB Industries calibration substrate comes complete with extremely precise elements. Devices on the calibration substrates represent opens, shorts, matched loads and throughs. When used properly, the devices insure accurate RF/Microwave test results.

The advantages of the GGB Industries calibration substrate offering, when used with a Micromanipulator RF/Microwave Probe Station include:

• Support of precise SOLT (Short, Open, Load, Through), LRM (Line, Reflect, Match) and LRL (Line, Reflect, Line) calibrations
• Convenient alignment of open, short, matched load and through devices
• Support of probe pitch ranges from 30 to 1,250 microns
• Suitable for frequency ranges from DC to 220GHz
• Support of GS, SG and GSG footprint configurations

Cables
Many cables needed for RF/Microwave measurements are available through Micromanipulator. Consult the individual probe or probe head configuration guide for exact cable requirements.

Variety of shielding methods
Micromanipulator offers a number of probe station light, EMI, RFI and moisture shielding options.

• Light/EMI/RFI entire station shield through the LTE series of enclosures
• Light/EMI/RFI/Moisture chuck chamber plus probe shield through "Top Hat" enclosures for the 8000 and P200-300 series stations