摘要 |
The disclosure is related to an SSRM method for measuring the local resistivity and carrier concentration of a conductive sample. The method includes contacting the conductive sample at one side with an AFM probe and at another side with a contact electrode, modulating, at a modulation frequency, the force applied to maintain physical contact between the AFM probe and the sample while preserving the physical contact between the AFM probe and the sample, thereby modulating at the modulation frequency the spreading resistance of the sample; measuring the current flowing through the sample between the AFM probe and the contact electrode; and deriving from the measured current the modulated spreading resistance. Deriving the modulated spreading resistance includes measuring the spreading current using a current-to-voltage amplifier, converting the voltage signal into a resistance signal, and filtering out from the resistance signal, the resistance amplitude at the modulation frequency. |