Contents Abstract I 致謝 III Contents IV List of Figures VI List of Tables XIII Chapter 1 Introduction 1 Motivation 2 Outline of the Thesis 3 Chapter 2 Background 4 2.1 Principles of Perpendicular Recording 4 2.1.1 Introduction 4 2.1.2 Basic Concepts of Perpendicular Recording 5 2.1.3 Typical Writing Process of PMR 6 2.1.4 Required Magnetic Properties of High Density PMR [2] 7 2.2 Layer Structures of PMR 9 2.2.1 Adhesion Layer 9 2.2.2 Soft Magnetic Underlayer 9 2.2.3 Intermediate Layer 10 2.2.4 Recording Layer 12 2.2.5 Capping Layer 13 2.3 Magnetic Recording Layer and Intermediate Layer 13 2.3.1 Granular CoPtCr-SiO2 Recording Layer 13 2.3.2 Intermediate Layer 20 2.4 The Origin of Noise of the PMR 31 2.4.1 The Soft Underlayer [34] 31 2.4.2 The Recording Layer 32 Chapter 3 Experimental 39 3.1 Experimental Flow Chart 39 3.2 Ultra-High Vacuum Sputtering System (UHV) 39 3.3 Analysis Technique 41 3.3.1 Vibrating Sample Magnetometer (VSM) 41 3.3.2 Perpendicular Magneto-Optical Kerr Effect Meter (PMOKE) 42 3.3.3 Atomic Force Microscopy (AFM) 43 3.3.4 X-Ray Diffraction (XRD) 44 3.3.5 Transmission Electron Microscope (TEM) 45 3.4 Read and Write (R/W) Test 46 Chapter 4 Results and Discussion 47 4.1 Current Full-Stack Perpendicular Recording Media 47 4.2 Improvement on the Intermediate Layers 49 4.2.1 Ta/Ru Intermediate Layers 49 4.2.2 Effect of NiW and Pt 54 4.2.2 Dual Ru Intermediate Layers 57 4.2.3 MnRu Intermediate Layer 69 Chapter 5 Summary 73 References 74   List of Figures FIGURE 1- 1 THE WRITING PROCESS OF THE PMR FILM 2 FIGURE 2- 1 ILLUSTRATION OF THE MAGNETIZATION AND THE DEMAGNETIZATION FIELD 5 FIGURE 2- 2 ILLUSTRATIONS OF THE LONGITUDINAL MEDIA AND THE PERPENDICULAR MEDIA 5 FIGURE 2- 3 WRITING PROCESS IN (A) LONGITUDINAL AND (B) PERPENDICULAR RECORDING 6 FIGURE 2- 4 COMPARISONS OF THE ANISOTROPY FIELD OF VARIOUS RECORDING 7 FIGURE 2- 5 THE HYSTERESIS LOOP OF PMR WITH DIFFERENT PARAMETERS 8 FIGURE 2- 6 THE FILM STRUCTURES OF PERPENDICULAR RECORDING MEDIUM 9 FIGURE 2- 7 ILLUSTRATION OF EPITAXIAL GROWTH OF RU AND RECORDING LAYER ON FCC STRUCTURE [2] 11 FIGURE 2- 8 HIGH-RESOLUTION TEM IMAGE OF 16NM THICK COPTCR-SIO2 MAGNETIC LAYER [19] 14 FIGURE 2- 9 DEPENDENCE OF KU OF THE COPTCR-SIO2 MEDIA ON THE MAGNETIC LAYER THICKNESS [19] 14 FIGURE 2- 10 DEPENDENCE OF HC AND MR/MS OF THE COPTCR-SIO2 MEDIA ON THE MAGNETIC LAYER THICKNESS [19] 15 FIGURE 2- 11 VALUES OF COERCIVITY HC AS A FUNCTION OF SIO2 CONTENT FOR COPTCR-SIO2 MEDIA WITH VARIOUS FILM THICKNESS [20] 15 FIGURE 2- 12 TEM BRIGHT FIELD IMAGES OF COPTCR-SIO2 MEDIA WITH VARIOUS SIO2 CONTENTS [20] 16 FIGURE 2- 13 VALUES OF KUV/KBT AS A FUNCTION OF SIO2 CONTENT FOR MEDIA WITH VARIOUS FILM THICKNESS [20] 16 FIGURE 2- 14 VALUES OF KU FOR {[CO90CR10]80PT20}100-Z-(SIO2)Z MEDIA AS A FUNCTION OF SIO2 CONTENT [20] 17 FIGURE 2- 15 TEM BRIGHT FIELD IMAGES OF COPTO FILMS. OXYGEN TO CO AVERAGE CONTENT RATIOS WERE (A) 6.7% (B) 14% (C) 24% [21] 17 FIGURE 2- 16 THE TEM BRIGHT FIELD IMAGE OF COPTCRO MAGNETIC LAYER[22] 18 FIGURE 2- 17 TEM IMAGES FOR THE MEDIA WITH 10 (TOP), 15(MIDDLE), AND 21(BOTTOM) AT% OXYGEN[23] 19 FIGURE 2- 18 HC AND MS DEPENDENCE ON OXYGEN CONTENT FOR CO-CR-PT-SI-O PMR MEDIA. SELECTED VSM HYSTERESIS LOOPS ARE SHOWN AS WELL.[23] 20 FIGURE 2- 19 DEPENDENCE OF PERPENDICULAR HYSTERESIS CURVES FOR SAMPLES WITH RU LAYERS DEPOSITED AT 5, 10, AND 20MTORR 21 FIGURE 2- 20 SUFACE MORPHOLOGIES OF THE RU FILMS DEPOSITED AT DIFFERENT WORKING PRESSURE 21 FIGURE 2- 21 CROSS-SECTIONAL TEM IMAGE OF A 16.7NM THICK COCRPT-SIO2 MAGNETIC FILM DEPOSITED ON THIN DEVELOPED (RU2/RU1) UNDERLAYER OF 11.9 NM THICKENSS [24] 23 FIGURE 2- 22 COMPARISON OF COERCIVITY DEPENDENCES ON RU UNDERLAYER THICKNESS [24] 23 FIGURE 2- 23 COMPARISON OF RECORDING PERFORMANCE FOR MONOPOLE HEAD OF MEDIA WITH DIFFERENT RU UNDERLAYER [24] 23 FIGURE 2- 24 STRUCTURE OF PERPENDICULAR RECORDING MEDIUM THAT USES NUCLEATION CONTROL SN LAYER (INDICATED BY ARROW) [28] 24 FIGURE 2- 25 GRAIN SIZE DISTRIBUTION OF THE IL2 LAYER PREPARED WITHOUT AND WITH THE NUCLEATION CONTROL SN LAYER [28] 24 FIGURE 2- 26 PLAN-VIEW TEM IMAGES OF THE IL2 LAYER PREPARED 25 FIGURE 2- 27 (A) SCHEMATIC OF MEDIA LAYER STRUCTURE (B) CROSS-SECTION TEM IMAGE [30] 26 FIGURE 2- 28 GRAIN SIZE DISTRIBUTIONS OF CO GRAINS IN MEDIA DEPOSITED ON RU90CR10 LAYERS WITHOUT OXYGEN AND OXYGEN [31] 27 FIGURE 2- 29 DEPENDENCE OF HC (SOLID LINE) AND SQ (BROKEN LINE) ON CR CONTENT OF NMIL WITH THE RECORDING MEDIA WITH PT-CR NMIL [32] 28 FIGURE 2- 30 CROSS-SECTIONAL TEM IMAGES OF THE PMR FILMS WITH (A) PT AND (B) PT-CR NMILS. RIGHT FIGURES SHOW SADPS [32] 28 FIGURE 2- 31 COMPARISON OF LAYER STRUCTURES OF RECORDING MEDIA WITH (A) THE CONVENTIONAL INTERMEDIATE LAYER DESIGN AND (B) THE MAGNETIC INTERMEDIATE LAYER DESIGN [33] 29 FIGURE 2- 32 COERCIVITY AND △Θ50 OF HCP (00.2) PEAKS OF COCRPT-SIO2 LAYERS FOR DIFFERENT THICKNESSES OF THE COCR INTERMEDIATE LAYER [33] 30 FIGURE 2- 33 RECORDING PERFORMANCE OF COCRPT-SIO2 DISKS PREPARED ON TA/COCR/RU1/RU2 WITH DIFFERENT RU1 LAYER THICKNESS AND TA/RU1/RU2 INTERMEDIATE LAYERS (SHOWN AT THE 6NM POSITION IN THE X AXIS) [33] 30 FIGURE 2- 34 A SCHEMATIC OF MAGNETIC BIAS SOFT UNDERLAYER FILM [34] 31 FIGURE 2- 35 NOISE SOURCE MODEL FOR PERPENDICULAR RECORDING MEDIA [3] 32 FIGURE 2- 36 RECORDING DENSITY DEPENDENCE OF SNR AND NORMALIZED MEDIA NOISE [35] 33 FIGURE 2- 37 (A) EXAMPLE OF A SERIES OF RECOIL LOOPS MEASURED ON A COCRPT ALLOY. (B) NORMALIZED DCD REMANENCE CURVES EXTRACTED FROM THE RECOIL LOOPS. THE OPEN CIUCLES AND SOLID CIRCLES ARE REPRESENTED THE UNCORRECTED AND CORRECTED DCD CURVES, RESPECTIVELY. THE OPEN SQUARE REPRESENTED SFD.[37] 36 FIGURE 2- 38 (A) EXAMPLES OF A SERIES OF RECOIL LOOPS (B) THE OPEN CIRCLES REPRESENT IRM CURVE, AND THE SOLID CIRCLES REPRESENT △M OF THE PERPENDICULAR COCRPT FILM MENTIONED ABOVE [36] 37 FIGURE 2- 39 THICKNESS DEPENDENCE OF THE △M FOR THE COCRPT ALLOY[38] 38 FIGURE 2- 40 △M DEPENDENCE OF THE EFFECTIVE DEMAGNETIZATION FACTOR (SOLID LINE) AND THE SFD (DASHED LINE)[38] 38 FIGURE 3- 1 THE UHV SPUTTERING SYSTEM 40 FIGURE 3- 2 THE TRANSFER MANIPULATOR IN THE LOADING CHAMBER 40 FIGURE 3- 3 THE PICTURE OF VSM 41 FIGURE 3- 4 THE SCHEME DIAGRAM OF VSM 42 FIGURE 3- 5 THE SCHEME DIAGRAM OF PMOKE 43 FIGURE 3- 6 THE SCHEME DIAGRAM OF AFM 44 FIGURE 3- 7 THE SCHEME DIAGRAM OF XRD INSTRUMENT 45 FIGURE 3- 8 STANDARD POST-PROCESSING OF COMMERCIAL DISK 46 FIGURE 4- 1 XRD PATTERNS OF TA/COPTCR-SIO2/RU/PT/TA/SUB. 47 FIGURE 4- 2 HYSTERESIS LOOP OF THE FULL-STACK PERPENDICULAR RECORDING MEDIA 48 FIGURE 4- 3 (A) PLANE VIEW TEM IMAGE AND (B) CROSS-SECTION TEM IMAGE OF THE FULL-STACKED COPTCR-SIO2 PERPENDICULAR RECORDING MEDIA 48 FIGURE 4- 4 GRAIN SIZE DISTRIBUTION OF COPTCR-SIO2LAYER 48 FIGURE 4- 5 XRD PATTERNS OF TA/RU/TA/SUB. WITH DIFFERENT DEPOSITION POWER OF THE BOTTOM TA LAYER 50 FIGURE 4- 6 ROCKING CURVES OF RU (00.2) PEAKS OF SAMPLES WITH TA LAYERS DEPOSITED BY DIFFERENT POWERS. 51 FIGURE 4- 7 THE FWHM OF RU HCP(0002) PEAKS AS A FUNCTION OF DIFFERENT DEPOSITION POWER OF TA LAYER 51 FIGURE 4- 8 XRD PATTERNS OF TA/RU/TA/SUB. WITH DIFFERENT TA LAYER THICKNESS 52 FIGURE 4- 9 ROCKING CURVES OF THE RU HCP(00.2) TEXTURE OF SAMPLES WITH DIFFERENT TA LAYER THICKNESS 53 FIGURE 4- 10 THE FWHM OF RU (00.2) PEAKS PLOTTED AS A FUNCTION OF TA LAYER THICKNESS (NM) 53 FIGURE 4- 11 THE PHASE DIAGRAM OF NIW 55 FIGURE 4- 12 THE Θ-2Θ SCAN RESULTS OF THE PMR FILMS WITH (A) NIW INTERMEDIATE LAYER AND (B) PT INTERMEDIATE LAYER 55 FIGURE 4- 13 THE HYSTERESIS LOOPS OF THE FILMS WITH PT INTERMEDIATE LAYER AND NIW INTERMEDIATE LAYER, RESPECTIVELY 56 FIGURE 4- 14 THE THORNTON DIAGRAM [48] 57 FIGURE 4- 15 XRD PATTERNS OF THE FILMS WITH DIFFERENT TOP RU LAYERS DEPOSITED BY DIFFERENT POWERS 58 FIGURE 4- 16 ROCKING CURVES OF (A) THE RU (00.2) PEAKS AND (B) THE CO (00.2) PEAKS OF THE FILMS WITH DIFFERENT TOP RU LAYERS DEPOSITED BY DIFFERENT POWERS 59 FIGURE 4- 17 △Θ50 OF RU AND COPTCR-SIO2 (00.2) PEAKS AS A FUNCTION OF THE DEPOSITION POWER OF THE TOP RU LAYER 59 FIGURE 4- 18 HYSTERESIS LOOPS OF COPTCR-SIO2 FILMS WITH RU LAYERS DEPOSITED BY DIFFERENT DEPOSITION POWER 61 FIGURE 4- 19 COERCIVITY OF COPTCR-SIO2 MEDIA AS A FUNCTION OF THE DEPOSITION POWER OF THE TOP RU LAYER 61 FIGURE 4- 20 Α VALUE AS A FUNCTION OF THE DEPOSITION POWER OF THE TOP RU LAYER 61 FIGURE 4- 21 XRD PATTERNS OF COPTCR-SIO2 FILMS WITH DIFFERENT BOTTOM RU LAYER THICKNESS 63 FIGURE 4- 22 ROCKING CURVES OF RU AND CO (0002) PEAKS AS A FUNCTION OF THE BOTTOM RU LAYER THICKNESS 63 FIGURE 4- 23 HYSTERESIS LOOPS OF THE FILMS WITH DIFFERENT BOTTOM RU LAYER THICKNESS 64 FIGURE 4- 24 HC AS A FUNCTION OF THE BOTTOM RU LAYER THICKNESS 64 FIGURE 4- 25 XRD PATTERNS OF THE FILMS WITH DIFFERENT THICKNESS RATIO OF THE BOTTOM RU LAYER THICKNESS TO THE TOP RU LAYER THICKNESS 65 FIGURE 4- 26 ROCKING CURVES OF CO HCP(00.2) PEAKS OF FILMS WITH DIFFERENT THICKNESS RATION OF THE BOTTOM RU LAYER TO THE TOP RU LAYER 66 FIGURE 4- 27 △Θ50 OF COPTCR-SIO2 HCP(00.2) PEAKS AS A FUNCTION OF THE BOTTOM RU LAYER THICKNESS 66 FIGURE 4- 28 HYSTERESIS LOOPS OF THE FILMS WITH DIFFERENT THICKNESS RATIO OF THE BOTTOM RU LAYER THICKNESS TO THE TOP RU LAYER THICKNESS 68 FIGURE 4- 29 Α VALUES AS A FUNCTION OF THE BOTTOM RU LAYER THICKNESS 68 FIGURE 4- 30 HC AS A FUNCTION OF THE BOTTOM RU LAYER THICKNESS 68 FIGURE 4- 31 THE MNRU PHASE DIAGRAM 69 FIGURE 4- 32 THE CRYSTAL STRUCTURE OF MNRU. THE ARROWS MEAN THE DISORDER MAGNETIZATION OF MN. 70 FIGURE 4- 33 THE Θ-2Θ XRD SCANS OF THE FILMS WITH MNRU INTERMEDIATE LAYER AND WITH PURE RU LAYER, RESPECTIVELY 71 FIGURE 4- 34 THE HYSTERESIS LOOPS OF THE FILMS WITH DIFFERENT MNRU LAYERS AND WITH RU LAYER ONLY, RESPECTIVELY 72   List of Tables TABLE 2. 1 LIST OF THE INTERMEDIATE LAYERS AND THE RECORDING LAYERS 11 TABLE 2. 2 COMPARISONS OF DIFFERENT PERPENDICULAR MEDIA [18]. 12 TABLE 2. 3 MAGNETIC PROPERTIES OF COCRPTO MEDIA WITH RU AND RU-OXIDE ILS [30] 26 TABLE 4. 1 THE COERCIVITY, NUCLEATION FIELD AND SQUARENESS OF THE HYSTERESIS LOOPS OF THE PMR FILMS WITH THE PT INTERMEDIATE LAYER AND THE NIW INTERMEDIATE LAYER, RESPECITVELY 56 TABLE 4. 2 THE COERCIVITY AND SQUARENESS OF THE FILMS WITH DIFFERENT INTERMEDIATE LAYERS 72