Surface-Charge-Layer Sheet-Resistance Measurements for Evaluating Interface RF Losses on High-Resistivity-Silicon Substrates

Surface-charge-layer sheet resistance (SCL-R_SH) current-voltage differential measurements on ring-gate metal-insulator-semiconductor field-effect transistor structures are proposed as an alternative to S-parameter transmission line and capacitance-voltage measurements to evaluate the interface RF losses on high-resistivity-silicon substrates. Argon implantation is employed to amorphize the silicon surface, thus increasing the SCL-R_SH. The RF attenuation decreases as R_SH increases, if other microwave losses (substrate, metallization, and radiation losses) are kept at the same low level. Full suppression of the surface losses is achieved for high-dose implants, giving SCL-R_SH ~ 6.0·10⁷ Ω□, minimum RF losses and voltage independent behavior of both parameters.