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

Surface-charge-layer sheet resistance
$({\hbox{SCL-}} R_{\rm SH})$
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
${\hbox{SCL-}}R_{\rm SH}$
. The RF attenuation decreases as
$R_{\rm SH}$
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
${\hbox{SCL-}}R_{\rm SH}\sim {\hbox {6.0}}\cdot {\hbox{10}}^{7}~\Omega/\square$
, minimum RF losses and voltage independent behavior of both parameters.