University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 1-1-1987 Reactively sputter-deposited titanium oxide and barium silicon titanate thin films. Toru Yamashita University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Recommended Citation Yamashita, Toru, "Reactively sputter-deposited titanium oxide and barium silicon titanate thin films." (1987). Electronic Theses and Dissertations. 6149. https://scholar.uwindsor.ca/etd/6149 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). 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UMI* REACTIVELY SPUTTER-DEPOSITED TiO„ AND Ba^Si_Ti0o THIN FILMS X 4 £ a by Toru Yamashita A Dissertation Submitted to the Faculty of Graduate Studies Through the Department of Engineering Materials in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor Windsor, Ontario Windsor, Ontario March,1987 UMI N um ber: DC53246 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright materia! had to be removed, a note will indicate the deletion. UMI Microform DC53246 Copyright 2009 by ProQuest LLC All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 C Toru Yamashita To My Parents i ABSTRACT Thin films of titanium oxide and bar ium-silicon-titanium oxide have been fabricated by reactive sputter depositon using metallic targets. The focus of the present study has been the relationships between deposition conditions and the resulting properties of the films. The deposition unit was equipped with a triode sputtering source and an auxiliary rf power supply. The flow rates of the sputtering gas (Ar) and the reactive gas (02 ) were controlled by mass flowmeters. Substrate heating was initially achieved with a ceramic heater. During the course of the work, a tantalum wive heater was designed and developed for use at higher substrate temperatures. The sputter-deposition parameters monitored in this experiment included the oxygen flow rate, the argon flow rate (which was converted to an equivalent partial pressure), the rf power density applied to the target, and the substrate temperature. Additional important parameters for the fabrication of the barium-silicon-titanium oxide thin films were the structure and the composition of the metallic target source. The deposited films were analyzed with a variety of techniques, including x-ray diffractometry, x-ray photoelectron spectroscopy, Rutherford backscattering ii spectroscopy, and Raman spectroscopy. For the titanium oxide films the electrical resistivity was measured as a function of temperature to determine the conduction mechanism for each film. Phase relations in the titanium oxide films were summarized by plotting the substrate temperature versus the oxygen flow rate to give a "metastable phase diagram". This diagram was in reasonable agreement with similar diagrams published in the literature and was also in agreement with the electrical conduction mechanism diagram constructed in the present work. The data for the average structure and composition of the films obtained by x-ray diffraction, Raman spectroscopy, and Rutherford backscattering spectroscopy were in good mutual agreement. X-ray photoelectron spectroscopy revealed the presence of a fully oxidized surface layer on all the analyzed samples, regardless of the film deposition conditions. A metallic target containing barium, silicon, and titanium with the respective atomic ratios of 2 :2:1 was prepared by combining the techniques of induction melting and powder sintering. The relative compositions of barium-silicon-titanium oxide films reactively sputter deposited from the metallic target were determined by x-ray photoelectron spectroscopy. For samples deposited at a ill substrate temperature of 70° C, the relative titanium content increased and the relative silicon content decreased as the argon partial pressure was reduced and/or the applied rf power density was raised. The conditions for obtaining stoichiometric Ba jSi 2 TiOg thin films were projected from these data. ACKNOWLEDGEMENTS The author wishes to express his gratitude to Dr. Hisao Yamauchi for his supervision, guidance and friendship throughout the course of this 3tudy and during his entire tenure at •.he University of Windsor. Acknowledgements are extended to Dr. W.V. Youdelis for his invaluable discussions and help in using induction furnace. The author is grateful to Mr. J.W. Robinson of the University of Windsor for hi3 assistance in the maintenance of the sputter deposition system and electron microscopy analysis. The author is also grateful to Dr. R. Aroka of the University of Windsor for his great help on the Raman Spectroscopy analysis and to Dr. M. Sayer of Queen's University for hi3 helpful discussion and assistance. The author is indebted to Mr. G. DeMagglo, Dr. B. Chao, Mr. J. Tyler and Dr. T. Takagi of the Energy Conversion Device Inc., Troy, Michigan. The author is also grateful to Dr. Y. Miyasaka and Dr. M. Kimura, Nippon Electric Company, Tokyo, Japan for their offering the useful information’ of fresnoite. The author wishes to express his gratitude to Dr. Whitten of Queen's University for his help of the use of Rutherford backscattering spectroscopy. Acknowledgements are also extended to Mr.R. White and Mr.P. Kawa for their V help. Assistance of computer programming by Mr. D.Curry of the University o i Windsor was appreciated. Finally, the author would like to thank Miss Kerene Boong and his friends and members of his family for their support and encouragement throughout this study. Vi TABLE OP CONTENTS ABSTRACT............................................. i ACKNOWLEDGEMENTS............................. lv TABLE OF CONTENTS........................................... v* LIST OF TABLES............................................... lx LIST OF FIGURES.............................................. * CHAPTER 1 INTRODUCTION................................ l CHAPTER 2 LITERATURE REVIEW.......................... 5 2.1 OPTICAL PROPERTIES OF CERAMICS........... 5 2.2 ELECTRICAL PROPERTIES OF NON­ CRYSTALLINE SEMICONDUCTORS 6 2.3 PIEZOELECTRIC THIN FILMS... .............. U 2 . 4 SPUTTERING. ................................ 12 2.41 DIODE SPUTTERING............................ 12 2.4 2 MAGNETRON SPUTTERING...................... 13 2.43 - TRIODE SPUTTERING.................... I3 2 . 44 REACTIVE SPUTTERING. ................ 1* 2.5 THIN FILM ANALYSIS METHODS............... 15 2.51 XPS (X-RAY PHOTOELECTRON SPECTROSCOPY)............................... 15 2.52 RUTHERFORD BACKSCATTERING SPECTROSCOPY................................ 16 2.53 RAMAN SPECTROSCOPY........................ 17 2.6 FILM THICKNESS MEASUREMENTS.............. 18 2.7 TITANIUM OXIDES................... 20 2.71 EQUILIBRIUM PHASE DIAGRAM........ .'....... 20 2.72 STRUCTURES................................... 21 vii 2.?3 OPTICAL PROPERTIES........................ 22 2.74 ELECTRICAL PROPERTIES....... 24 2.8 FRESNOITE................................... 26 CHAPTER 3 TiO x THIN FILMS............................ 29 3.1 EXPERIMENTAL PROCEDURE........... 29 3.11 TARGET PREPARATION........................ 29 3.12 THIN FILM PREPARATION..................... 29 3.13 THICKNESS MEASUREMENTS.................... 32 3.14 PHASE AND COMPOSITION ANALYSES.......... 33 3.15 RESISTIVITY MEASUREMENTS.................. 34 3.2 RESULTS AND DISCUSSION.................... 36 3.21 DEPOSITION RA TE ......... 36 3.22 PHASE RELATIONS .................... 38 3.221 X-RAY DIFFRACTOMETRY..................... 38 3.2 22 X-RAY PHOTOELECTRON SPECTROSCCr ........ 42 3.223 RUTHERFORD BACKSCATTERING SPECTROSCOPY................................ 46 3.224 RAMAN SPECTROSCOPY......................... 50 3.225 COMPARISON OF METASTABLE PHASE DIAGRAMS............................. 53 3.23 RESISTIVITY................................. 56 CHAPTER 4 Ba2Sl2Ti08 THIN FILMS..................... 63 4.1 EXPERIMENTAL PROCEDURE.................... 62 4.11 TARGET PREPARATION......................... 62 4.12 THIN FILM PREPARATION........ 64 4.13 THICKNESS MEASUREMENTS.................... 66 4.14 PHASE AND COMPOSITION ANALYSES........... 66 Viii 4.2 RESULTS AND DISCUSSION..................