4D SeriesResistivity

The industry standards for Sheet Resistivity and Capacitance Voltage mapping are now offered by Toho Technology through our partnership with Four Dimensions.

Four-Point Probe Software
Four-Point Probe Software
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CV Mapping Software
CV Mapping Software
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Contact Us

(773) 583-7183


Spec Sheet

4D SeriesThe Four Dimensions Four-Point Probe uses two current-supplying and two voltage-sensing probes to provide highly accurate and reproducible sheet resistivity and thickness measurements on a wide variety of materials. The system is built on a Windows 7 platform and features user-friendly “one-touch” operation and auto-calibration. Capable of measuring 50 sites in 90 seconds, measurements range from 1mΩ/sq to 800kΩ/sq and extend up to 8E11Ω/sq.


• 120 Manual System
• 280 Bench-top 200mm
• 300 Bench-top 300mm
• 1100 Flat Panel


Wafer Sizes Accommodated: 50, 75, 100, 125, 200 mm

Test Diameter: Up to 3mm from wafer edge

Measurement Range: 1mΩ/sq. to 800kΩ/sq. or 8E9 Ω/sq.

Measurement Units: Ω/sq., Ω-cm, V/I, μ [T], Å[T]

Measurement Repeatability: <0.2% (typical)

Quick-Checks: 1, 5, 9 sites | 5, 6, 9, 10, 13 site ASTM/SEMI | X-patterns or custom sites

Cartesian Maps: Any site-interval ≥0.1 mm, up to 6000 sites

Electronic Accuracy: <0.1% (precision resistor)

Current Resolution: 16 Bit A/D

Compliance Voltage for Measurement: 125V


• P/N type testing
• Silicon substrates
• Epi Layers
• Ion Implant dose & Uniformity
• Poly resistivity & thickness
• Metal deposition monitor
• Silicide process monitor
• Ion Implant diffusion
• Poly gate process monitor
• Metals
• Poly-Si, a-Si


• Capable of making measurements without a computer
• Standard resistor network and firmware allowing easy and quick electronic calibration
• Assembled with easily replaceable modules
• Optional trouble shooting kits available for quick and easy on-site troubleshooting
• Diagnostic program available for hardware and software
• Low price precision durable probe head

4D SeriesDesigned for superior repeatability, accuracy, and safety, the CV Mapping system uses Four Dimensions’ patented inverse mercury probe technology to measure capacitance voltage directly on non-patterned wafers without damaging samples. The unique Mercury Refresh feature improves performance by ensuring clean contact, with no mercury left on samples after testing. The spill-proof reservoir requires replacement only twice a year. Built on a Windows 7 interface, the system is user-friendly and versatile for both R&D and production applications.


• CV-Map 92 semi-automatic / 200mm
• CV-Map 3093 semi-automatic / 300mm
• CV-Map 3093C cassette to cassette
• CV-FP Flat Panel Display
• CVR CV + Sheet Resistance 


Capacitance Measurement Range: 0 to 20,000 pF through internal meter, or limited by the specification of the external meter

Current Measurement Range: 50fA to 1 mA

Bias Available: -100 to 100 V internal, or specified by the external meter up to 1000V

Measurement Pulse: 50mV, 100mV, >20µ for Ch, >1ms for Cq

Wafer Size: From 1 cm x 1 cm square chip to 8" or 12" round wafer

Probe: Mercury dot from 2x10⁻⁵ cm² to 0.8 cm², without mercury ring, or with 1-2 mercury rings or external probe station


• Thickness and k value for high/low k films
• Carrier density profiling
• Epi layer mapping
• Low dose ion implant layers
• Oxide integrity (Vbd, Qbd)
• Furnace contamination monitor
• SOI wafer characterization
• USJ layer carrier density profiling


• Refreshed mercury before each contact ensures clean contact
• Easy-to-change probe head
• Minimal probe head to wafer contact area
• Non scratching poly-carbonate probe head material