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Langmuir-Blodgett (LB) films have previously been used as organic insulating layers in compound semiconductor metal-insulator- semiconductor devices, with promising preliminary results. This thesis describes the first investigation of the use of LB films In gallium arsenide metal-insulator-semiconductor devices. Diodes incorporating thin layers of w-tricosenoic acid or substituted copper phthalocyanine possessed 'leaky' electrical characteristics, i.e. there is some conduction through the LB film. This 'leaky' behaviour was exploited to produce the first metal- Insulator-semiconductor-switch (MISS) incorporating an LB film. MISS devices on n-p(^+) GaAs were produced with good switching characteristics and a high yield (~90%), using LB film thicknesses between 9 and 33 nm. It was shown that the 'punch through' mechanism was responsible for the switching behaviour. p-n(^+) GaAs/LB film MISS diodes behaved rather differently, with good switching characteristics only found at reduced temperature. Some degradation of the characteristics of LB film MISS devices was noted, although this was reduced by using the more robust phthalocyanlne LB films. Metal-tunnel-insulator-semiconductor diodes were produced on the ternary alloy Ga(_.47)In(_.53)As, using LB film monolayers. The barrier height was apparently larger than that of Schottky barriers on this material, with a very substantial reduction in current density due to tunnelling through the LB film. Using this technique it may be possible to produce very high performance GaInAs fleld-effect-transistors, which are analogous to GaAs metal-semiconductor field effect transistors.

This thesis studies the effects of gas ambients on the electrical properties of the insulator-semiconductor interface of a MIS capacitor. A microcomputer-controlled instrumentation system has been developed to extract this information from measurement of the a.c. admittance of MOS or MIS devices. The system incorporates several novel developments in circuitry and software which enable these admittance data to be automatically collected and processed in the frequency domain by remote recalibration of the instrumentation. This advancement permits interface state density information to be calculated more quickly and accurately than has been previously possible using manually-operated equipment. The system has been used to investigate the influence of gases on the density of interface states in a MIS capacitor, in particular the palladium/silicon dioxide/silicon structure which is sensitive to hydrogen gas. A distinct change in the distribution of surface state density across the silicon bandgap has been observed upon exposure to a hydrogen ambient. An alternative insulating layer, an organic Langmuir-Blodgett film multilayer of ω-tricosenoic acid, has been characterised and examined, and increased sensitivity of this structure to hydrogen gas has been indicated.

Metal-insulator-semiconductors (MIS) are one of the most basic elements in the digital and microwave circuits. Theoretical and experimental investigation has shown that the dominant mode of propagation in MIS is not a quasi-TEM mode at all frequencies. It has been shown that an MIS transmission line is in fact a slow-wave structure in a certain frequency range. Slow-wave structures offer a large effective permittivity, therefore, can be employed to create large propagation delay and to reduce the guided wavelength. These characteristics can be utilized to design compact passive elements such as delay lines, phase shifters and filters. MIS structures can be easily fabricated using the current semiconductor technology. As well, they can be designed to operate in the slow-wave region for implementation of miniaturized passive components. In this thesis, first, an MIS interconnect is designed, fabricated and measured. Then, the transmission line characteristics are extracted from simulated and measured results. Subsequently, the MIS line parameters are used in designing a compact slow-wave meander line structure, which is compatible with silicon-based-packaging (SBP) solutions used in modern system-in-package/system-on-package (SIP/SOP) technologies.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 2, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Materials Engineering, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. / The properties-of systems which undergo a metal-insulator (MI) transition are currently being extensively studied. Both the transport and thermodynamic properties of these MI systems show interesting behaviour, particularly near the MI transition. A complete theory to describe MI systems does not yet exist. In the present work the focus is on the thermodynamic properties of MI systems, in particular on the specific heat and susceptibility. The thermodynamic properties in the absence of a magnetic field are now well understood, with models such as the two-fluid model giving a good account of the behaviour. In finite magnetic fields the thermodynamic properties are even more interesting and varied. It is the aim of the present work to develop and test models to explain the effects of applying magnetic fields to MI systems. The focus is mainly on phosphorous doped silicon, and the results are gratifying. The theory should, however, also apply to other similar MI systems. / Andrew Chakane 2018

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Metal-insulator-semiconductor switches (MISS), in which the T denotes some form of thin semi-insulating layer and the semiconductor part consists of a pn junction, are part of the general class of regenerative switching devices which includes the thyristor. The switching behaviour of the MISS derives from the ability of the MIS junction to exhibit current gain and to exist in two modes, deep depletion and inversion. In this thesis, a general model for the regenerative switching is proposed after investigating the properties of the MIS junction both theoretically and experimentally. Results from MIS diodes with tunnelling-thickness oxide Mayers indicate that interface states play a dominant role in their electrical behaviour and that the uniformity of the oxide is poor, giving rise to a large spread in the current-voltage characteristics. Subsequently, the epitaxial form of the MISS device is investigated and in particular the importance of isolation of the pn junction. It is concluded that spreading effects set a practical lower limit to the device dimensions, making the epitaxial form unsuitable for microelectronic applications. An alternative semi-insulator, 'silicon-rich oxide' (SRO) is introduced as an optional I-layer with possibly greater integrity than tunnel oxide. MIS diodes formed with SRO are shown to have very similar properties to tunnelling diodes. Large area devices fabricated using this material are surprisingly discovered to exhibit stable negative differential resistance (NDR). Although this discovery at first appears to be contrary to normal circuit stability criteria and to the regenerative feedback model itself, both of these points are resolved. It is shown that the frequency of oscillation of an unstable device is controlled by the external circuit. Then it is proposed that if this frequency is greater than the maximum frequency of operation of the regenerative mechanism, stable NDR is observed. In the final chapter, alternative lateral MISS structures which should overcome the geometrical limitations of epitaxial devices are discussed.