MBE Growth of Alinn and Bi2se3 Thin Films and Hetero-Structures

MBE Growth of Alinn and Bi2se3 Thin Films and Hetero-Structures
Author: Ziyan Wang
Publisher: Open Dissertation Press
Total Pages:
Release: 2017-01-26
Genre:
ISBN: 9781361285299

This dissertation, "MBE Growth of AlInN and Bi2Se3 Thin Films and Hetero-structures" by Ziyan, Wang, 王子砚, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract:  Molecular Beam Epitaxy is an advanced method for the synthesis of single-crystal thin-film structures. However, the growth behavior varies case by case due to the complicated kinetic process. In this thesis, the epitaxial growth processes of AlxIn1-xN alloy and Bi2Se3 thin-films are studied. Heteroepitaxial growth of AlxIn1-xN alloy on GaN(0001) substrate is carried out in the Nitrogen-rich flux conditions. A series of transient growth stages are identified from the initiation of the deposition. A significant effect of source beam-flux on the incorporation rate of Indium atoms is observed and measured. A correlation between the incorporation rate and the growth conditions (flux ratio and growth temperature) is revealed by the dependence of the growth-rate of the film on beam fluxes. A mathematic model is then suggested to explain the effect, through which the measured results indicating a surface diffusing and trapping process is indicated. Unexpected behavior of the lattice-parameter evolution of the growth front during deposition is also observed, indicating a complex strain-relaxation process of the epilayers. For three-dimensional (3D) topological insulator of Bi2Se3, growths are attempted on various substrate surfaces, including clean Si(111)-(7x7), Hydrogen terminated Si(111), Bismuth induced Si(111) reconstructed surfaces, GaN(0001), and some selenide "psudo-substrates." The specific formation process of this quintuple-layered material in MBE is investigated, from which the Van der Waals epitaxy growth characteristics inherent to deposition of Bi2Se3 is determined, and the mechanism of the "two-step growth" technique for this material is further clarified. Among the various substrates, those that are inert to chemical reaction with Bi/Se are important for the growth. The epilayers' lattice-misfit with the substrate is also a crucial factor to the structural quality of the Bi2Se3 epifilms, such as the defects density and the single-crystalline domain size. The effect of a vicinal substrate on suppressing the twin-defects in film is also addressed. Using a suitable substrate and adapting an optimal condition, ultra-thin films of Bi2Se3 with a superior structural quality have been achieved. Multilayered Bi2Se3 structures with ZnSe and In2Se3 spacers are attempted. Finally the high-quality superlattices of Bi2Se3/In2Se3 are successfully synthesized. The hetero-interfaces in the superlattice structure of Bi2Se3/In2Se3 are sharp, and the individual layers are uniform with thicknesses being strictly controlled. The behaviors of strain evolution during the hetero-growth process are finally investigated. An exponential relaxation of misfit strain is observed. And the correlation between the residual strain and the starting surface in the initial growth stage is also identified. DOI: 10.5353/th_b4716348 Subjects: Aluminum alloys Indium alloys Bismuth compounds Selenium compounds Thin films Heterostructures Molecular beam epitaxy

Thin Films: Heteroepitaxial Systems

Thin Films: Heteroepitaxial Systems
Author: Amy W K Liu
Publisher: World Scientific
Total Pages: 706
Release: 1999-06-01
Genre: Technology & Engineering
ISBN: 9814496405

Heteroepitaxial films are commonplace among today's electronic and photonic devices. The realization of new and better devices relies on the refinement of epitaxial techniques and improved understanding of the physics underlying epitaxial growth. This book provides an up-to-date report on a wide range of materials systems. The first half reviews metallic and dielectric thin films, including chapters on metals, rare earths, metal-oxide layers, fluorides, and high-Tc superconductors. The second half covers semiconductor systems, reviewing developments in group-IV, arsenide, phosphide, antimonide, nitride, II-VI and IV-VI heteroepitaxy. Topics important to several systems are covered in chapters on atomic processes, ordering and growth dynamics.

Thin Film Growth Techniques for Low-Dimensional Structures

Thin Film Growth Techniques for Low-Dimensional Structures
Author: R.F.C. Farrow
Publisher: Springer
Total Pages: 572
Release: 1987-12
Genre: Science
ISBN:

This work represents the account of a NATO Advanced Research Workshop on "Thin Film Growth Techniques for Low Dimensional Structures", held at the University of Sussex, Brighton, England from 15-19 Sept. 1986. The objective of the workshop was to review the problems of the growth and characterisation of thin semiconductor and metal layers. Recent advances in deposition techniques have made it possible to design new material which is based on ultra-thin layers and this is now posing challenges for scientists, technologists and engineers in the assessment and utilisation of such new material. Molecular beam epitaxy (MBE) has become well established as a method for growing thin single crystal layers of semiconductors. Until recently, MBE was confined to the growth of III-V compounds and alloys, but now it is being used for group IV semiconductors and II-VI compounds. Examples of such work are given in this volume. MBE has one major advantage over other crystal growth techniques in that the structure of the growing layer can be continuously monitored using reflection high energy electron diffraction (RHEED). This technique has offered a rare bonus in that the time dependent intensity variations of RHEED can be used to determine growth rates and alloy composition rather precisely. Indeed, a great deal of new information about the kinetics of crystal growth from the vapour phase is beginning to emerge.

Study of III -Nitrides Heterostructures Grown by Molecular Beam Epitaxy

Study of III -Nitrides Heterostructures Grown by Molecular Beam Epitaxy
Author: Che Woei Chin
Publisher: LAP Lambert Academic Publishing
Total Pages: 124
Release: 2011-05
Genre:
ISBN: 9783844392678

Various techniques have been used to grow III-nitride heterostructures including metalorganic vapor deposition, hydride vapor epitaxy and molecular beam epitaxy (MBE). Among these techniques, MBE presents a number of advantages such as precise control of layer thickness and composition. MBE is a highly sophisticated system which thin film quality is sensitive to the growth parameters. From the literature, a systematic growth procedure has not been well-documented. This book presents an in depth understanding of MBE growth mechanism which is essential for thin film quality improvement. Detailed study on the growth mechanism allows the acquisition of the fundamental knowledge in growing precise optoelectronics device structures. This book focuses on the study of III-nitride thin films grown by MBE on various aspects, supported by analysis using a variety of structural and optical characterization techniques. The book starts with the introduction of the MBE architecture, follows by the detailed growth procedures. The characterization and analysis of various III-nitride thin films grown on Si and sapphire will be presented in the last part of the book.