Scanning Spreading Resistance Mode (SSRM)

Scanning Spreading Resistance Mode (SSRM) is a technique based on contact mode that is is frequently used to map the variation in majority carrier concentration in doped semiconductors. Sensor Signal is the electric current between the conductive tip and sample for an applied DC bias, VDC.  Using a logarithmic amplifier, SSRM measures the current by referencing it to an internal resistor, thereby yielding a local resistance value.