RUI (Collaborative Research): Ion and Radical Beam Tailored Oxide, Nitride, and Germanide Electronic Film Materials

Tarleton State University, Stephenville TX

Investigators

Abstract

This is an RUI collaborative research project among three physics programs at neighboring state universities: Angelo State University, Tarleton State University, and Southwest Texas State Uni-versity. The project focuses on three main topics: (1) correlation between electrical and optical properties and stress in ZnO and nitrogen-doped ZnO fabricated at reduced temperatures using radical atomic beam processing, (2) feasibility of fabricating predicted ZnO-Mn and Zn-Co room temperature transparent magnetic semiconductors, and (3) dielectric properties of select amor-phous or potentially epitaxial insulator oxide alloys consisting of Pr-Al-O, Gd-Ga-O, Hf-Al-O, Pr-Zr-O and La- Hf-O (most with possible oxynitridation and alloy-dependent band gap variabil-ity) relevant for magnetic spin tunneling structures and next-generation CMOS gate applications. A study towards the stabilization and characterization of metastable Ni-incorporated Cu-Ge and Co- Ge thin film crystalline phases will also be included. Thin film materials fabrication will be conducted using ion beam sputter processing strategies. The approach is to implement mono-energetic Ar + or Xe + ions (<1 keV) to control incident film adatom energy (between ~ 6 eV to ~ 20 eV), and vary the substrate angle of incidence to promote kinetic film growth at reduced temperatures with and without reflected energetic Ar/Xe atom bombardment. Low energy (<100 eV) reactive (O2 + /N2 + ) assist ion beams will be compared with neutral thermal atomic radi-cals to promote optimal oxidation (and dopant nitridation) at reduced substrate temperatures. The implementation of in-situ low energy and/or neutral atomic radical species to promote reactive sputtering is relatively unique for ion beam sputtering and is not possible with magnetron sput-tering due to its higher operating pressure regime. The group also has the capability of processing sputtered films with rapid thermal annealing and high-energy (< 1 MeV) inert ion mixing to study germanide formation in amorphous deposited metal-Ge films. %%% The project addresses fundamental research issues in a topical area of materials science having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. Undergraduates from all three universities will be involved in multiple phases of the research, with strong participation from underrepresented groups. In addition to ion beam sputtering, students will be involved with rapid thermal process-ing, electrical transport studies, ion beam analysis, scanning electron microscopy with EDS, ad-vanced x-ray diffraction and fluorescence analysis, magnetometry, and optical characterization (reflectivity, FTIR, photoluminescence). In addition, students will have a chance to collabora-tively interact with Central Texas microelectronics industry scientists and doctoral institution re-search teams interested in the project. All three collaborating universities are close enough to permit an active degree of inter-university group visits and student exchanges to support the re-search. The research will encourage students to consider pursuing research at various materials-related doctoral programs, or consider further education in a professional masters program. In addition, the broad thin film materials experience gained from the project will be useful prepara-tion for student internships in the microelectronics industry and strengthening the workforce pool of educated BS/MS graduates for this critical industry. ***