The QuadMap features tools necessary for engineers to define meaningful test parameters and operators to quickly load a sample and test.

Operators simply place the sample on the vacuum chuck, close the door, enter the ID of the test sample and press the Start button. The sample loads, and begins testing. A typical 50 location test, on a 300mm wafer will complete in less than one minute. During the test, the results table displays each test site’s results and highlights in red for failures.

At the conclusion of the test, the data is automatically stored in a database. Operators may view the wafer graphs in up to 5 different formats including 2D black & white, 2D color, 3D, 3D half X and 3D half Y. Statistical results shown include Avg, Std Dev, 1Sigma, Max and Min. Operators may also print a report (printer not included) or export data to a spread sheet and save to a USB flash drive.

Engineers define and create tests to verify the processing tolerances are in compliance. They define the test modes including autorange or current setting, dual configuration, sensitivity and pass/fail tolerances. Additionally, engineers will also define the number of test sites up to 14,000, which probe head is installed, sample size, edge exclusion, etc. Once a test is defined, it is stored in the test list. Of course, Engineers have all of the same privileges as operators and can run the tests desired.

Engineers will also appreciate the powerful trending tool provided by QuadMap. With the data automatically stored into a data base; after a number of tested samples, engineers can sort the results and identify trends effecting the measured samples.

QuadMap is defined for the production environment. Bright polished stainless steel skins and other materials assure Fab ready operation. A modular design assures that if a failure does occur, a field service technician can quickly replace the errant part.

·   High speed measurements of thin films, wafers and solar tiles.

·   Reports sheet resistance Ohms per square and resistivity in Ohms per cm.

·   Available in 150mm, 156mm square, 200mm and 300mm configurations

·   Speed: 50 points per minute with standard configuration

·   Dual configuration: applies the standard ## to automatically correct for geometric errors caused by probe spacing and/or edge proximity , improving overall accuracy

·   Auto-range: finds the ideal current setting to meet the parameters of the standard for measuring.

·   Standard range: 1mΩ to 100MΩ per square

·   P/N typing

·   5 different 2D and 3D mapping to choose from

·   Data is automatically stored and may be exported to a spread sheet.

Optional SECSII/GEM interface allows control and ability to upload data from FAB management system

Key features in all Signatone systems include auto-range and dual configuration. Auto-range automatically finds the ideal current setting to meet the parameters of the standard for measuring. At the first test site, the software controls the current source to step through a number of settings until the measured voltage is in target range as defined by the standard. This current is then used for all subsequent measurements of the sample. Dual configuration mode applies the standard ## to automatically correct for geometric errors caused by probe spacing and/or edge proximity improving overall accuracy.

Signatone offers 3 product families- The QuadMap for production, the QuadPro for R&D and the Pro4 for basic, manual measurements. Each family has a variety of options and configurations. With over 60 configurations to choose from, Signatone has the product that will meet your application.

Lucas Signatone QuadPro Resistivity System

·   Reports average resistivity, resistivity standard deviation, average sheet resistance and sheet resistance standard deviation

·   Temperature coefficient of resistance (TCR) measurements integrated with automated temperature chuck and source meter (optional).

·   Automated 2D & 3D contour mapping

·   Employs the dual configuration testing method for improved accuracy and repeatability

·   For samples 10 to 300mm

·   1 to 49 NIST traceable automated measurements per sample 

QuadPro Automatic System

The QuadPro includes a computer, stepper controller, and base station with either a 200 or 300mm diameter isolated chuck.

The software allows for selecting 1, 5, 9, 25 or 49 points for automated testing and mapping of the test sample. Positioning patterns may be set to either round or square configuration.

The edge exclusion may also be defined. On the first measurement, the software auto ranges the meter finding the best settings for the sample testing. Dual configuration assures that errors introduced by the probe head manufacturer are eliminated, increasing the repeatability and accuracy of measurements. The Software controller automatically steps to each position and records the X-Y position, Sheet Resistance, Resistivity and V/I measurement in a visible table.

Upon completion of the test points, a wafer contour map is displayed. The contour map may be toggled between 2D and 3D viewing. The average and standard deviation of resistivity and sheet resistance display prominately above the contour map. 

The Temperature Coefficient of Resistance option integrates temperature control of the test sample as well as the automated source meter control and resistance calculations. Integrated with a variety of Signatone thermal chuck systems, the test allows setting of temperature steps in degrees C, dwell time at temperature before reading, starting temperature and ending temperature. Each temperature, and resistance reading is stored in a table and plotted on a graph for analysis.

Signatone offers a variety of thermal chucks and temperature ranges. The standard, most common range is ambient to 350°C. However, different combinations of chucks and controllers could have a low of -55°C to a high of 600°C.

The QuadPro standard configuration includes the Keithley 2400 Source Measurement Meter. This meter allows resistance measurements in the range of 1 milliohm to 2 megaohms. Some of the newer high resistance materials require a greater resistance measurement range. For those applications, Signatone implements the Agilent 4156 Parametric Analyzer along with special triaxial shielding. This configuration increases the range from 100 millohms to 10 gigaohms, see to the right. 

Four Point Probe Heads

Signatone offers two probe heads to choose from; the SP4 and the HT4. The SP4 is an inline probe made of delrin and used in most applications. Several choices are available for configuration to your specific application. The three spacings are .040, .050 and .0625 inches. The three pressures available are 45, 85, and 180 grams. Tips are made of Tungsten Carbide or Osmium and a choice of .0016, .005, .010 inches radius.

The HT4 inline four point probe head looks similar to the SP4 but is made of ceramic and designed for high temperature and high resistance measurements. The HT4 accurately collects data at temperatures up to 650°C. The coaxial high temperature wiring also allows resistance measurements up to 10 Gigohms. The HT4 features spacing of .050 and .0625 inches and pressure is fixed at 180 grams. Tips are made of Tungsten Carbide or Osmium and a choice of .0016, .005, .010 inches radius.

QuadPro Test & Calibration

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%.

Specifications

Automation: Select min temperautre, max temperature, interval and dwell time, then auto
Run Display: Temp, Rs, resistivity or thickness
Calculate TCR or Map Rs @ Temperature.

Output: 2D and 3D contour maps, save and get results, print results including contour maps, copy to clip board, etc. Retest function.

                Probe Heads