S-302-4

The Signatone S-302-4 includes a 100 mm probe stand and a four-point probe head with 5 mil radius tips spaced at 40 mil intervals. The S-302-4 is used to make sheet resistance and resistivity measurements of substrates and thin films. The S-302-4 interfaces with a Keithley 2450 SourceMeter to perform these measurements. The S-302-4 is part of a probe station system that also includes a Cascade MicroTech EPS150TRIAX probe station.^[1][2][3]

The S-302-4 operates by lowering the four-point probe head into contact with the sample using a lever arm. The probe tips are compressed between 50% and 70% of their travel during contact. The probe height can be adjusted using a Z-adjust knob. Current is sourced through the outer probes and the voltage is measured across the inner probes, allowing calculation of sheet resistance using a correction factor that accounts for sample geometry.^[3]

The S-302-4 is used with Keithley KickStart software for measurement control and data export. Measurements can be performed in two-wire or four-wire configurations. The Keithley 2450 provides voltage and current sourcing and measurement capability.^[1]

The S-302-4 is used for ex situ characterization of thin films and substrates in a laboratory or cleanroom environment. Sheet resistance and resistivity measurements are performed after film deposition or substrate preparation to evaluate electrical properties. The tool is typically employed during process development, quality control, and research investigations rather than in-line production wafer mapping.

The S-302-4 is used for sheet resistance and resistivity measurements of substrates and thin films. Applications include I-V characterization, low-current measurements, C-V characterization, and resistance and conductance measurements. The tool is suitable for measuring the sheet resistance of conductive inks, transparent conductive oxides, metal films, and other thin-film materials.^[1][4][5]