Magneto-Optical Investigations of Surface Space-Charge Layers in Metal-Oxide - Semiconductor (Mos) Systems.

The effect of finite boundaries on the Faraday rotation and ellipticity due to the two dimensional electron gas (2DEG) formed in the inversion layer of a metal-oxide-semiconductor (MOS) system is considered. Although the 2D Drude model is mainly used, many body effects are also considered using the memory-function approach. The validity of using a 2D model for the inversion layer is justified by showing its equivalence to a three dimensional model which includes multiple reflections within the inversion layer. The free carriers in the metal gate are investigated by calculating the surface admittance of the gate. It is found that the admittance is independent of temperature in the range 4 - 300(DEGREES)K, and due to surface scattering, the effect of the gate is small. We also find that the effect of a finite oxide layer enhances the rotation by 21%, due to multiple reflections. For a finite semiconductor substrate the transmission coefficient is shown to be a periodic function of the semiconductor thickness. This leads to very large enhancements due to interference effects. In an effort to improve agreement between theory and experiment the memory-function approach is used to write down the magneto-conductivity. However it is found that at fields \u3e 1 x 10(\u275) G unusually high mass enhancements are obtained