Application of the Shubnikov-de Haas oscillations in the characterization of Si MOSFET's and GaAs MODFET's

The Shubnikov-de Haas magnetoconductance oscillations were used to measure directly the gate-to-channel capacitance of Si MOSFET's and GaAs MODFET's, to detect the onset of parallel conduction in GaAs MODFET's, and to provide an approximate measure of channel length in sub-100-nm channel of Si MOSFET's. The measurements do not require knowledge of any device parameters, are immune to any gate parasitic capacitance, and are independent of source and drain series resistances. One needs to know only the magnetic field, the oscillation period (for gate-to-channel capacitance measurement), the gate voltage (for detection of the onset of parallel conduction), and the number of oscillation peaks (for the channel length characterization). Experimental results have shown that the characterization methods are accurate, and can be applied to FET's with sub-100-nm channel length.