Application of novel O- and H-atom sources in molecular beam epitaxy

Abstract

Room-temperature growth of ZrO 2 thin films using a novel hyperthermal oxygen-atom source Determination of the atomic nitrogen flux from a radio frequency plasma nitride source for molecular beam epitaxy systems An intense atomic hydrogen source with a movable nozzle output Rev.A novel source based on electron stimulated desorption ͑ESD͒ has been developed for the production of O-atom and H-atom fluxes. The fluxes produced by these sources are greater than 10 15 atoms/cm 2 s with an ion-to-atom ratio of about 10 Ϫ8 , and no other contaminants are present. During operation in a typical molecular beam epitaxial ͑MBE͒ system, the pressure remains below 10 Ϫ9 Torr. The energies of the atoms range from about 1 to 4 eV, and no high energy species, which would damage a surface, are present in the flux. Therefore, these ESD atom sources are superior to plasma sources in all respects. The application of these sources for the in situ, room-temperature cleaning of GaAs and InP surfaces, the room-temperature growth of an insulating oxide layer on GaAs͑001͒, and the room-temperature MBE growth of ZrO 2 are described.

Electron bombardment of water adsorbed on Zr(0001) surfaces

“…We make this assignment based on the fact that there is no significant temperature rise of the sample during electron bombardment even at very high fluence. The electrons probably initiate hydrogen and deuterium electron stimulated desorption (ESD) [15][16][17][18][19][20], which alters the low temperature thermal desorption features near 320 K by depleting the adsorbed H/D and OH/OD species known to exist on this surface at these temperatures [21,22]. This sharpens up the 320 K hydrogen feature, possibly due to selective ESD depletion of either one type of species or of the same species at different binding sites.…”

Structural, Optical and Electrical Properties of HfO2 Thin Films Deposited at Low-Temperature Using Plasma-Enhanced Atomic Layer Deposition

“…The root mean square (RMS) roughness values of the HfO 2 films (50 nm) were obtained by Atomic Force Microscope (AFM, XE7, Park Systems Suwon, Korea) images and scanned at 2 µm × 2 µm size. The chemical bonding states and components were examined by using X-ray photoelectron spectroscopy (XPS, K-Alpha+, Thermo Fisher Scientific Waltham, MA, USA) To remove carbon-and nitrogen-contaminant layers from air, approximately 7 to 10 nm of the HfO 2 films was removed via Ar etching, at 1 keV, for 30 s [25,26]. Refractive index and absorption coefficient of HfO 2 (50 nm) were extracted from the Ellipsometry (SE, M2000D, J.A.…”

In-Situ Oxygen-Atom Erosion Study of a Polyhedral Oligomeric Silsesquioxane (POSS)-Siloxane Copolymer Using a Novel Hyperthermal Oxygen Atom Source and Analysis by X-Ray Photoelectron Spectroscopy

“…traditional polymer systems via copolymerization, grafting and blending processes.^-/ (22)(23)(24)(25)(26)(27). The operational concept of the hyperthermal oxygen atom generator is shown in Fig.…”