Herstellung und Untersuchung metallischer Einzel-Elektronen-Transistoren

Hofmann, Karl; Kurz, Heinrich (Thesis advisor)

Aachen : Publikationsserver der RWTH Aachen University (2001)
Dissertation / PhD Thesis

Aachen, Techn. Hochsch., Diss., 2001

Abstract

Single-electron transistors (SETs) are quantum devices and are based on the controlling of the Coulomb blockade. They are the ultimate development of low-power devices with an extreme high potential of integration. Their dominant purpose is seen in future memory devices. Usually the key element of all metallic SETs is a tunnel junction consisting of a metal-insulator-metal transition. In this current thesis the microscopic and electrical investigations of e-gun evaporated titanium thin films are presented in detail. Also the properties of TI/TiOX/Ti junction are discussed. Titanium films containing a fiber texture with a grain size of up to 25nm show a decreasing resistivity with falling temperature. Whereas the resistivity of films built of random orientated crystals with a significantly smaller grain size of 15nm increases with falling temperature. Based on simulations results of the SET characteristics three different conceptions of planar and vertical metallic SETs were developed and investigated using improved methods of nano-technology. The lateral dimension of all fabricated SETs are less than 50nm and their operation temperature was between 4.2K and 77K. The electrical characteristics of the devices include all typical Coulomb features of single-electron devices: blockade, staircase and oscillations.