Mobility Characterization by Magnetoresistance in Ultra Thin SOI Ring-FETs

We report a novel use of magneto-resistance (MR) to estimate carrier mobility in ultra-thin virgin SOI wafers. Measurements were made in pseudo-MOSFET configuration with electrical contacts in Corbino geometry and substrate biasing. The use of high magnetic fields enabled accurate extraction of electron mobility as a function of gate voltage (effective field) and film thickness. The MR mobility values are large and correlate well with the field-effect mobility determined in pseudo- MOSFETs at zero magnetic field.