The trend towards miniaturisation of microelectronic devices and the search for exotic new optoelectronic devices based on multilayers confer a crucial role on semiconductor interfaces. Great advances have recently been achieved in the elaboration of new thin film materials and in the characterization of their interfacial properties, down to the atomic scale, thanks to the development of sophisticated new techniques. This book is a collection of lectures that were given at the International Winter School on Semiconductor Interfaces: Formation and Properties held at the Centre de Physique des Rouches from 24 February to 6 March, 1987. The aim of this Winter School was to present a comprehensive review of this field, in particular of the materials and methods, and to formulate recom mendations for future research. The following topics are treated: (i) Interface formation. The key aspects of molecular beam epitaxy are emphasized, as well as the fabrication of artificially layered structures, strained layer superlattices and the tailoring of abrupt doping profiles. (ii) Fine characterization down to the atomic scale using recently devel oped, powerful techniques such as scanning tunneling microscopy, high reso lution transmission electron microscopy, glancing incidence x-ray diffraction, x-ray standing waves, surface extended x-ray absorption fine structure and surface extended energy-loss fine structure. (iii) Specific physical properties of the interfaces and their prospective applications in devices. We wish to thank warmly all the lecturers and participants, as well as the organizing committee, who made this Winter School a success.

The trend towards miniaturization of microelectronic devices and the search for exotic new optoelectronic devices based on multilayers confer a crucial role upon semiconductor interfaces. Great advances have recently been made in the production of new thin-film materials and in the characterization of their interfacial properties down to the atomic scale, thanks to the development of sophisticated new techniques. This book is a collection of lectures given by specialists at the International Winter School on "Semiconductor Interfaces: Formation and Properties," which was held at the Centre de Physique des Houches from 24 February to 6 March, 1987. The following topics are particularly emphasised: - Interface formation, including molecular beam epitaxy, the fabrication of artificially layered structures, strained layer superlattices and the tailoring of abrupt doping profiles. - Characterization down to the atomic scale using techniques such as STM, HRTEM, SEXAFS and SEELFS. - Specific physical properties of the interfaces and their prospective device applications.

Using the continuum of interface-induced gap states (IFIGS) as a unifying theme, Mönch explains the band-structure lineup at all types of semiconductor interfaces. These intrinsic IFIGS are the wave-function tails of electron states, which overlap a semiconductor band-gap exactly at the interface, so they originate from the quantum-mechanical tunnel effect. He shows that a more chemical view relates the IFIGS to the partial ionic character of the covalent interface-bonds and that the charge transfer across the interface may be modeled by generalizing Pauling?s electronegativity concept. The IFIGS-and-electronegativity theory is used to quantitatively explain the barrier heights and band offsets of well-characterized Schottky contacts and semiconductor heterostructures, respectively.

The trend towards miniaturisation of microelectronic devices and the search for exotic new optoelectronic devices based on multilayers confer a crucial role on semiconductor interfaces. Great advances have recently been achieved in the elaboration of new thin film materials and in the characterization of their interfacial properties, down to the atomic scale, thanks to the development of sophisticated new techniques. This book is a collection of lectures that were given at the International Winter School on Semiconductor Interfaces: Formation and Properties held at the Centre de Physique des Rouches from 24 February to 6 March, 1987. The aim of this Winter School was to present a comprehensive review of this field, in particular of the materials and methods, and to formulate recom mendations for future research. The following topics are treated: (i) Interface formation. The key aspects of molecular beam epitaxy are emphasized, as well as the fabrication of artificially layered structures, strained layer superlattices and the tailoring of abrupt doping profiles. (ii) Fine characterization down to the atomic scale using recently devel oped, powerful techniques such as scanning tunneling microscopy, high reso lution transmission electron microscopy, glancing incidence x-ray diffraction, x-ray standing waves, surface extended x-ray absorption fine structure and surface extended energy-loss fine structure. (iii) Specific physical properties of the interfaces and their prospective applications in devices. We wish to thank warmly all the lecturers and participants, as well as the organizing committee, who made this Winter School a success.

Semiconductor interfaces are of paramount importance in micro, nano- and optoelectronics. Basic as well as applied research on such systems is therefore of extremely high current interest. To meet the continuous need for a better understanding of semiconductor interfaces with respect to both their fundamental physical and chemical properties as well as their applications in modern opto- and microelectronics, the series of international conferences on the formation of semiconductor interfaces was begun. The fourth conference of the series held in Jülich addresses as main topics: clean semiconductor surfaces; adsorbates at semiconductor surfaces; metal-semiconductor, insulator-semiconductor and semiconductor-semiconductor interfaces; devices and wet chemical processes. The 12 invited lectures assess the present status of the research in important areas and about 180 contributed papers describe most recent achievements in the field.