Four Dimensions' Four Point Probe systems measure the sheet resistance / resistivity / thickness of a wide range of materials. We offer a wide range of models, options, and probe heads to suit your materials', measurement, and budget needs. We can also tailor systems to your special requirements.

• All our four-point probe systems (except computerless models) can be modified to measure the pn junction leakage of USJ (range 1E-9 to 1E-2 S/cm2).
• We can extent range up to 8E9 Ohms/square or 8E11 Ohms/square for poly Si or amorphous Si film sheet resistivity measurement.
• We offer precise four point probe head with special needle array, such as rectangular or parallelogram array.

Four Dimensions' Mercury Probe Systems use the liquid metal Mercury to form temporary non damaging electrical contacts on numerous materials. The instantaneous contact formed on semiconducting materials can be of MOS, MIS, or Schottky barrier type. This permits various electrical characterizations of for example silicon and compound semiconductors without the need of metal deposition processes.

Our unique Mercury probe design features outstanding safety and contact area repeatability. It permits us to offer the widest range of contact areas and probe head configurations. Mercury refreshing mechanism results in normally No Hg mark left on the test side. The mercury contacts can be a dot (3E-5 cm2 to 0.8 cm2) or a dot and one or more rings, as well as a linear array of four probes. Thus our systems can probe on a variety of substrates including insulators, as well as SOI structures.

Our automated Mercury probe systems come with unique capacitance and current meters that can perform C-V, I-V, Q-V, as well as V-t measurements. These measurements allow a wide range of sample characterization:

• Oxide integrity monitoring
• Doping density profiling, low dose ion implantation monitoring, and USJ doping profiling
• Carrier lifetime extraction
• Resistivity measurements of semi-insulating materials
• Pseudo MOST characterization of SOI structures (B systems)
• Ferroelectric sample investigations
• Poly Silicon characterization

See the application chart for more details.

Square waves are used to determine the quasistatic, deep pulse, and high frequency capacitance. Square wave probing is insensitive to series resistance and eliminates the need of phase adjustments required in conventional capacitance measurements using sinusoidal signals. The versatility of the system can be enhanced by accessories for external probing and by attaching external meters such as Agilent 4285A, or Keithley 590 C-V meters, or Keithley 2410 high voltage source.

Our Windows based CVmap software serves the needs of both, research and development as well as production line, environments. top

Based on decades of experience with needle four point probes and C-V, I-V Mercury probing stations, Four Dimensions developed a Mercury four point probe (patent pending). The liquid metal Mercury is used to form temporary electrical contacts at four terminals. These probes cause no damage to the sample and permit no contact pressure probing.

The system meets the requirements for ultra shallow junction probing, but may well be applied to other ultra thin films found for example in hard disks and flat panels.

Advantages of Mercury Probes:

• Non destructive probing
• No pressure probing
• Highly repeatable contact area

Basic features:

• Safe design principle
• Refreshed mercury before each contact insures clean contact
• Clean and safe Mercury handling
• Mercury reservoir replacement only twice a year

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• Combined C-V, I-V and four point probe mapping system
• all features of M4PP3093 and CVmap 3093 A/B combined
• Suited for the characterization of USJ

Four Dimensions' needle four point probe systems and mercury probing systems feature a modular structure. This structure allows us to provide manual, desktop, as well as fully automated systems in each product line. It also permits easy customization. If you have special requirements in sample size, sample handling, or measurement features, contact us to discuss them.

Examples of customization:

• We have pattern recognition hardware and software for alignment to patterns on the samples.
• We offer a hot chuck with our four point probes for high T measurements
• We offer all our systems with R-theta and x-y movement stages, which permits measurements of virtually any unconventionally sized and shaped sample.
• We customize stages for ingots.
• Extra external meters with GPIB control to enlarge the systems versatility.
• Our in-house software development permits tailoring the software to your needs.

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