The purpose of the four point probe is to measure the resistivity of any semiconductor material. It can measure either bulk or thin film specimen, each of which consists of a different expression.
Technical parameters
Highly repeatable needle contact conditions owing to controlled velocity of descent;
Individually adjustable needle loadings with direct indication of set load;
Solid tungsten carbide needles with precision radiused tips;
Fully visible contact area;
Micrometer controlled slice displacement;
Hinged steel cover to eliminate effects of light and electrical interference during measurement;
Specification – probe needles:
Material: 0.5 mm diameter tungsten carbide, 26 mm long, 45 degree included angle, 25 micron tip radius (or larger up to 100 microns);
Spacings: 1.00 mm, 1.27 mm, 1.59 mm – tolerance +/- 0.01 mm;
Travel 4 mm;
Insulation resistance: 2 x 105 megOhms at 500 volts;
Load: 0-100 grams applied by adjustable individual tension gauges;
Specimen: slice only, 76 mm diameter is normal maximum.
