The Signatone Pro4 provides simple answers to sheet and bulk resistivity measurements. Since 1968, Lucas-Signatone has offered an inline four point probing solution. To make the measurements, the user lowers the four-point probe head onto sample then selects the test button in the software. The computer automatically controls the instrument and steps through a number of current settings to find the ideal current for accurate readings.
A V/I measurement is taken and recorded. The system uses the Dual Configuration test method of ASTM Standard F84-99 to compensate for errors in probe spacing and errors caused by proximity to the edge of the conducting layer. NIST traceable calibration standards are available for purchase with the system. Proper use of the standards and the calibration procedure insures the specified system accuracy of better than 1%. The standard range of the system is 1 miliohm up to 800K ohms-per-square.
The Pro4-440N system includes: Keithley 2400, two four-point probe heads, Pro4 software, Pro4 stand, and a notebook PC.
The Pro4 software manages the tests, displays results and allows printouts or export of the data. The user inputs the size and shape of the sample, edge exclusion and number of points to be tested. The user may also define pass/fail criteria and which parameter (Sheet Resistance, Resistivity, or V/I) to display. A graphic picture of the target probe points is displayed. Prompts tell user to move to the next position. Upon completion of testing all points, the average, standard deviation, minimum and maximum are prominently displayed. Upon completion, a summary report may be printed showing the data and pass/fail status.
The Pro4-4400 is the same as the Pro4-440N, but without the computer. The customer supplies a PC running Windows 7 with one available RS-232 or USB port. The Pro4 is designed to measure resistivity and sheet resistance of wafers and other materials. The Pro4 applies the dual configuration method and autoranging to assure accurate measurements. The system includes the probe stand, two four point probe heads, the test meter (Keithley 2400), and software.
The Pro4-4000 does not include the PC or the meter, but it does include the software to run on a Windows 7 PC. The customer supplies the Keithley 2400 sourcemeter and the Windows 7 PC. The system includes the probe stand, two four point probe heads, and the software.