[표제지 등]
Abstract
표목차
그림목차
칼라
목차
PART 1 : 이온빔 표면분석법 연구 17
제1장 서론 19
제2장 본론 24
제1절 기초이론 24
1. Shadow cone 24
2. Close encounter probability 28
3. 결정내부에서의 Channeling 30
가. Average(continuum) potential 30
나. Critical angle 32
다. Minimum yield 34
라. Angular yield 35
4. Planar channeling 37
5. Channeling flux distribution 38
제2절 Channeling applications 40
제3절 Channeling simulation codes 48
1. Flux distribution 49
가. Binary collision model과 continuum model. 50
나. 챈널을 진행하는 이온의 에너지 손실 51
1) 원자핵에 의한 운동량변화량과 에너지 손실. 51
2) 전자에 의한 이온의 에너지 손실 52
2. Yield calculation과 lattice site location. 53
제4절 실험 56
1. Experimental setup 56
가. Chamber 56
나. Goniometer 56
다. Target holder 58
라. Electronics 58
2. 결정 정렬 방법 59
가. 결정의 주축을 찾는 일반적인 방법 60
나. 좌표변환 62
다. Goniometer의 영점정렬방법 67
라. Misalignment의 측정 68
마. 결정의 임의 방향을 빔방향으로 맞추는 방법 69
바. 일반적 결정정렬 방법의 타당성과 문제점 73
3. LabView 에 의한 계측시스템 자동화 82
가. LabView 의 개요 및 구성 82
1) LabView 의 개요 82
2) LabView 의 구성 83
나. LabView에 의한 goniometer control program 87
1) 기본 goniometer 구동 program 87
2) 임의의 공간각으로의 이동 92
다. 계측시스템의 자동화(goniometer, current integrator, MCA) 93
제5절 결과 및 논의 97
1. Goniometer Alignment 97
가. Optical alignment 97
1) 챔버 정렬 97
2) goniometer 정렬 98
나. 빔에 의한 goniometer 정렬 98
2. Si 및 GaAs 웨이퍼에 대한 시험분석 100
가. Si에 대한 시험분석 100
나. GaAs 에 대한 시험분석 105
다. Electron suppressor system의 성능 조사 108
제3장 결론 111
참고문헌 112
APPENDIX 1 115
PART 2 : 레이저유도 플라즈마 분광법 연구 119
제1장 서론 121
제2장 본론 123
제1절 레이저 유도 플라즈마 특성 123
1. 플라즈마의 공간적 특성 123
2. 레이저 파장 특성 126
가. 삭마되는 속도 126
나. 화구의 형상 127
다. 플라즈마의 특성 128
3. 초점 특성 132
4. 레이저 세기에 따른 플라즈마의 변화 136
제2절 정성분석 방법의 개발 140
1. 레이저 유도 플라즈마법에 의한 성분 분석의 특징 140
2. 분석 장치의 최적화 141
3. 표준 분광선 라이브러리 142
4. 정성분석 과정 144
제3장 결론 149
참고문헌 150
판권지 151
PART 1 : 이온빔 표면분석법 연구 15
Table 1.1. Channeling의 활용분야. 22
Table 2.1. Channeling parameters for some crystals for 1 MeV He. 27
Table 2.2. Critical angle and X min(이미지참조) for some lattices for 1 MeV He. Data taken from ref.[7]. 38
Table 2.3. Specification of the used goniometer 57
Table 2.4. Boards of which LabView has device drivers internally. 83
Table 2.5. Commands of MM3000 goniometer controller. 90
PART 2 : 레이저유도 플라즈마 분광법 연구 15
Table A.1. Species of screen function in interatomic potential 116
Table A.2. Species of interatomic screening length 117
Table 1. Standard reference materials for the spectral reference library. 143
PART 1 : 이온빔 표면분석법 연구 10
Fig. 1.1. Penetration of 40 keV 86Kr(이미지참조) in the principal crystallographic directions on Al and in amorphous Al₂0₃.[3] 19
Fig. 1.2. Artists conception of the channeling process on a microscopic scale.[6] 20
Fig. 1.3. An example of the interaction of incident ions with an aligned crystal. 21
Fig. 1.4. Blocking pattern for 150 keV protons incident on a tungsten crystal.[6] 23
Fig. 2.1. Concept of trapping of incident ions in a channel 25
Fig. 2.2. Formation of a shadow cone due to the Coulomb collision of incident ions on the first lattice atom. 25
Fig. 2.3. Simple binary collision model for the calculation of the shadow cone radius. 26
Fig. 2.4. Deduction of the shadow cone radius Rc. The minimum value of r₂is Rc(이미지참조). 27
Fig. 2.5. Flux distribution at the second atom layer as a function of the normalized impact parameter r₂/Rc(이미지참조). 29
Fig. 2.6. The scattering yield at the second atom I₂normalized to the surface peak intensity as a function of the thermal vibration amplitude. 29
Fig. 2.7. Simplified model for calculating the continuum potential. 30
Fig. 2.8. A plot of FRS(x') versus x'. FRS is the square root of the Moliere string potential fM. x'=1.2. 1/a in eq.(10)[7].(이미지참조) 32
Fig. 2.9. Fictitious crystal. The unit area of a string πr²o is shown together with the nonchanneling area πr²min‥(이미지참조) 34
Fig. 2.10. Model for the calculation of the angular yield. 36
Fig. 2.11. Simple theoretical angular yield curve. 37
Fig. 2.12. Flux distribution in a channel of cylindrical symmetry. Flux peaks at the center of the channel. 39
Fig. 2.13. Dechanneling particles by electrons and defects. 41
Fig. 2.14. Backscattering(Backscatering)spectra for random and (110) aligned Si crystal after implant damage. 42
Fig. 2.15. Schematic of four ion scatterings of reconstruction, relaxation, and adsorbate covered. 43
Fig. 2.16. Schematic of ion Scattering spectra for amorphous film on single crystal. 44
Fig. 2.17. Schematic of the backscattering spectra from different epitaxial layers. 45
Fig. 2.18. Angular scans of the normalized channeling for annealing to the various temperature. 46
Fig. 2.19. Schematic diagram of the goniometer used in the channeling experiment. 57
Fig. 2.20. Electronics for the channeling experiment. 59
Fig. 2.21. Example of the crystal considered through the rest of the chapter. 61
Fig. 2.22. Angular scan of a Al single crystal around [110] axis with tilting angle 3.8° for (p,γ) reaction originally done by Andersen et al. 61
Fig. 2.23. Stereographic representation deduced from Fig. 2.22 as is done by Andersen et al. They thought the misalignment of the sample (or the goniometric system) is given by the distance op, but it is not true as is verified later. 62
Fig. 2.24. Fixed (Lab) frame of reference. A,B,C are the goniometer rotational axis. b is the beam vector. 63
Fig. 2.25. Setup for the misalignment measurement of the goniometer using a well cut silicon wafer. 69
Fig. 2.26. Typical result of the misalignment measurement. The matching B angle increases drastically as A angle approaches ±90˚. 69
Fig. 2.27. The crystal coordinate is defined by the major axis →s and a vector →p in the major plane. Any direction →r relative to these two directions can be easily transformed to the CFR.(이미지참조) 70
Fig. 2.28. The crystal model for the explanation of the crystal alignment procedure. Any angle can be represented by the length on the sphere of r=1. 74
Fig. 2.29. Top view of the crystal model of Fig. 2.28. 74
Fig. 2.30. Crystal alignment when goniometer axis matches the major axis of the crystal and γ=0. 74
Fig. 2.31. Polar diagram for Fig. 2.32. the intersection precisely positions the crystal axis. 74
Fig. 2.32. Crystal alignment when goniometer axis does not matches the major axis of the crystal and γ=0. 75
Fig. 2.33. Trajectory of the beam (ABCD circle) on the sphere for Fig. 2.32. The beam vector matches the crystal plane at A,B,C,D. 75
Fig. 2.34a. Channeling minima for Fig. 2.33. 76
Fig. 2.34b. Polar diagram for Fig. 2.34a. 76
Fig. 2.35. Side view of the sphere model for the case of Fig. 2.33. The points B and D in Fig. 2.33 match P but ▲ in Fig. 2.34b appears as Q causing the difference between the measured tilt angle θm and the real angle θr.(이미지참조) 77
Fig. 2.36. Similar to the case of Fig. 2.33 but now assuming the rotation axis is not on the crystal plane. As (a) can be reduced to Fig. 2.33, the situation can be treated equally. 79
Fig. 2.37. General situation of the crystal alignment. When the misalignment angle γ is not known, the common procedure fails to find the real crystal axis. 80
Fig. 2.38. Finding the real crystal axis is possible by tilting in the misalignment direction when the misalignment γ is known. 81
Fig. 2.39. VI controls and indicators available in the panel(pannel). 85
Fig. 2.40. An example of block diagram. 86
Fig. 2.41. Flow chart of goniometer manipulation program. 88
Fig. 2.42. Front panel of the goniometer manipulation program. 91
Fig. 2.43. Flow chart of goniometer movement for arbitrary direction. 93
Fig. 2.44. Communications for automatic measurement & control between host PC and peripherals. 95
Fig. 2.45. Procedure of control and acquisition(aquisition) during polar scan 96
Fig. 2.46. Measurement of the exact port angles. 97
Fig. 2.47. Measurement of the misalignment angle. 100
Fig. 2.48. Polar plot of a {100} silicon wafer. 2.4 MeV He (a)Tilt angle=10°. (b) for tilt angle 60°. 101
Fig 2.49. Polar diagram of a {100} Silicon wafer. 2.4 MeV He, Tilting angle=10°. 102
Fig. 2.50. Angular scan of the {110} plane of silicon crystal. 103
Fig. 2.51. Backscattering yield of He on Si for random and {110} plane directions. 104
Fig. 2.52. Backscattering yield of He on Si for random, {100} plane and [110] directions. 104
Fig. 2.53. Polar plot of a [100] GaAs wafer. 0.5 MeV He Tilting angle =10°. 106
Fig. 2.54. Polar diagram of a [100] GaAs wafer. 0.5 MeV He, Tilting angle =10°. 106
Fig. 2.55. Angular scan of the {110} plane of GaAs for incident energy 107
Fig. 2.56. Backscattering yield of He on GaAs for random and {110} plane directions. 107
Fig. 2.57. Backscattering yield of He on GaAs for random, {100} plane and [110] directions. 108
Fig. 2.58. Secondary electron emission from target surface as functions of various ions, their energies and the bias voltage of the electron suppressor. 109
PART 2 : 레이저유도 플라즈마 분광법 연구 13
Fig. 1. Spatial plasma intensity distribution contour of the Zn based alloy sample. 124
Fig. 2. Simulated spatial distribution of Zn intensity in the plasma of the Zn based alloy sample. 125
Fig. 3. Mass ablation rate of Cu target with Nd:YAG laser wavelength variation. 127
Fig. 4. Crater shape difference with Nd:YAG laser wavelength variation 129
Fig. 5. Plasma characteristics with plasma height variation at copper target. (a) λ=1064 nm, (b) λ=532 nm, (c) λ=355 nm, E=30 mJ 130
Fig. 6. The laser induced plasma images of Copper target. The laser beam (1064 nm, 50 mJ) is over focused (a), right focused (b) and under focused (c). 133
Fig. 7. The laser induced plasma images of Copper target. The laser beam (532 nm, 50 mJ) is over focused (a), right focused (b) and under focused (c). 134
Fig. 8. The spectra of laser-induced plasma from the copper target at different focal position. 135
Fig. 9. The shapes of plasma at ablating energy of (a) 18 mJ, (b) 50 mJ, (c) 65 mJ and (d) 80 mJ using 1064 nm laser. 137
Fig. 10. The shapes of plasma at ablating energy of (a) 15 mJ, (b) 35 mJ, (c) 45 mJ and (d) 65 mJ using 532 nm laser. 138
Fig. 11. Background emission intensity variation with laser energy at Cu target. (1064 nm Nd:YAG laser) 139
Fig. 12. The experimental setup for laser-induced plasma spectroscopy for qualitative elemental analysis. 142
Fig. 13. LIBS spectrum of aluminum standard and its peak position. The LabCalc searches the peak position automatically with the preset parameters. 145
Fig. 14. Many library spectra can be opened on a working screen for comparison and decision of elements. The shown spectra are Al Co, Cr and Cu from top to down. 146
Fig. 15. The LIBS spectrum of NBS 626 Zn alloy. 147
Fig. 16. The LIBS spectrum of alloy coin 148