Ion implantation in β-Ga2O3: Physics and technology

Ion-beam modification of metastable gallium oxide polymorphs

Abstract: Structural changes under the action of Al+ irradiation have been investigated by X-ray diffraction for polymorphic Ga2O3 layers grown by halide vapor phase epitaxy on c-plane sapphire and consisting predominantly of α-phase with inclusions of e(κ)-phase. As a result of irradiation, some new reflections appear, which can be interpreted in two ways – either as a phase transition of the α- and/or e(κ)-phase to the more stable β-phase, or as a selective radiation-stimulated strain of the e(κ)-phase, i.e., an increase in the interplanar distance of a family of planes parallel to the surface. The discussed ion-stimulated phenomena have to be taken into account when utilizing ion implantation to modify Ga2O3 properties.

Ion-Beam Modification of Metastable Gallium Oxide Polymorphs

Abstract: Gallium oxide with a corundum structure ({\alpha}-Ga2O3) has recently attracted great attention in view of electronic and photonic applications due to its unique properties including a wide band gap exceeding that of the most stable beta phase (\b{eta}-Ga2O3). However, the lower thermal stability of the {\alpha}-phase at ambient conditions in comparison with the \b{eta}-phase requires careful investigation of its resistance to other external influences such as ion irradiation, ion doping, etc. In this work, the structural changes under the action of Al+ ion irradiation have been investigated for a polymorphic gallium oxide layers grown by hydride vapor phase epitaxy on c-plane sapphire and consisting predominantly of {\alpha}-phase with inclusions of {\alpha}(\k{appa})-phase. It is established by the X-ray diffraction technique that inclusions of {\alpha}(\k{appa})-phase in the irradiated layer undergo the expansion along the normal to the substrate surface, while there is no a noticeable deformation for the {\alpha}-phase. This speaks in favor of the different radiation tolerance of various Ga2O3 polymorphs, especially the higher radiation tolerance of the {\alpha}-phase. This fact should be taken into account when utilizing ion implantation to modify gallium oxide properties in terms of development of efficient doping strategies.

An Introduction to Solid State Diffusion

Abstract: The energetics and mechanisms of diffusion control the kinetics of such diverse phenomena as the fabrication of semiconductors and superconductors, the tempering of steel, geological metamorphism, the precipitation hardening of nonferrous alloys and corrosion of metals and alloys. This work explains the fundamentals of diffusion in the solid state at a level suitable for upper-level undergraduate and beginning graduate students in materials science, metallurgy, mineralogy, and solid state physics and chemistry. A knowledge of physical chemistry such as is generally provided by a one-year undergraduate course is a prerequisite, though no detailed knowledge of solid state physics or crystallography is required.

Secondary Ion Mass Spectrometry: An Introduction to Principles and Practices

Abstract: DESCRIPTION Serves as a practical reference for those involved in Secondary Ion Mass Spectrometry (SIMS) • Introduces SIMS along with the highly diverse fields (Chemistry, Physics, Geology and Biology) to it is applied using up to date illustrations • Introduces the accepted fundamentals and pertinent models associated with elemental and molecular sputtering and ion emission • Covers the theory and modes of operation of the instrumentation used in the various forms of SIMS (Static vs Dynamic vs Cluster ion SIMS) • Details how data collection/processing can be carried out, with an emphasis placed on how to recognize and avoid commonly occurring analysis induced distortions • Presented as concisely as believed possible with All sections prepared such that they can be read independently of each other