High-mobility mosfets with normal and superconducting gates

Among metallic systems, the two-dimensional electron gas (2DEG) is a class by itself. The reduced dimensionality has revealed a variety of new phenomena, and has generated a new generation of semiconductor devices. In this thesis I present a study on two-dimensional electron transport in high-mobility MOSFETs at temperature below 4.2 K. The electron transport mobility often serves as a characterization of the device quality, for scattering determines the length scales and the smearing of energy levels in the 2DEG. The essential ingredients in technology and handling to obtain a high mobility are discussed and the resulting device quality that is achieved, is compared with results by other groups. ... Zie: Summar