Optical effects of ion implantation P. D. TOWNSEND, P. J. CHANDLER and L. ZHANG School of Mathematical and Physical Sciences University of Sussex 1 CAMBRIDGE UNIVERSITY PRESS
Preface 1 An overview of ion implantation 1.1 Development of ion implantation 1.2 Properties influenced by ion implantation 1.2.1 Mechanical and chemical properties 1.2.2 Electrical properties 1.2.3 Optical properties 1.2.4 Optical properties controlled by surface layers 1.3 Processes occurring during ion implantation 1.3.1 Nuclear collisions and high defect densities 1.3.2 Point defects and electronic interactions 1.3.3 Synergistic effects 1.3.4 Radiation enhanced diffusion 1.3.5 Thermal effects 1.3.6 Compositional effects 1.4 A summary of the advantages of ion beam processing 1.5 Pattern definition 1.6 Energy and dose requirements 1.7 Summary of implantation effects 2 2.1 2.1.1 2.1.2 2.1.3 2.1.4 2.1.5 2.2 Ion ranges, damage and sputtering Predictions of range distributions Nuclear collisions Differential cross-section Electronic stopping Summary of nuclear and electronic stopping Ion range distributions Damage distributions page xiii 1 1 4 5 6 8 10 11 12 14 14 14 16 17 18 20 21 21 22 24 24 27 29 31 33 34 35 Vll
Vlll 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.2.6 2.2.7 2.2.8 2.2.9 2.3 2.4 2.5 2.5.1 2.5.2 2.5.3 2.5.4 Electronic defect formation Displacement threshold effects Diffusion, relaxation and amorphisation Stability of amorphised layers Amorphisation of semiconductors Stability of point and cluster defects Defect diffusion and crystallography Structural and compositional changes Conclusions on damage distributions Channelling Sputtering Computer simulations Simulation approaches Molecular dynamics Boltzmann transport equation State of simulation programs 3 Optical absorption 3.1 Analysis methods using absorption, ESR and RBS 3.2 In situ optical absorption 3.3 Crystallographic effects on stress and defect motion 3.4 Sapphire 3.5 Alkali halides 3.5.1 F and F 2 centres 3.5.2 F 3, F 2 ' and F 3 ' bands 3.5.3 Other features 3.6 Defect complexes 3.7 Growth curves 3.8 Molecular beam effects on absorption 3.9 Isotopic and ion species effects 3.10 Measurement of oscillator strength 3.11 ESR and ENDOR 3.12 High dose effects 3.12.1 Amorphisation 3.12.2 Colloids 3.12.3 Precipitate phases 3.13 Summary of problems in interpretation 4 4.1 Luminescence Luminescence processes 38 39 39 47 47 49 51 52 54 55 57 62 63 65 66 66 67 70 70 71 75 77 83 85 88 89 90 93 95 100 101 103 103 103 105 108 109 112 115 115
4.2 Luminescence during ion implantation 4.3 Effects of implantation temperature 4.4 In situ luminescence 4.4.1 Alkali halides - excitons 4.4.2 Alkali halides - a search for bi-excitons 4.4.3 CaF 2 4.4.4 Silica 4.4.5 Sapphire 4.4.6 LiNbCb - impurity and stoichiometric effects 4.4.7 LiNb0 3 - excitons 4.4.8 Surface impurity emission 4.4.9 Solid argon 4.4.10 Summary of in situ luminescence effects 4.5 Photoluminescence 4.5.1 Luminescence of NaF 4.5.2 Synthesis of new semiconductor alloys 4.5.3 Divacancies in sapphire 4.6 Waveguide lasers 4.7 Thermoluminescence 4.7.1 Silica and quartz 4.7.2 CaF 2 4.7.3 LiF dosimeters 4.8 Impurity doping of CaO 4.9 Cathodoluminescence 4.10 Depth effects 5 Ion implanted waveguide analysis 5.1 Characteristics of ion implanted waveguides 5.2 Waveguide mode theory 5.2.1 Maxwell equation approach 5.2.2 Quantum mechanics analogy 5.3 Waveguide coupling 5.3.1 End coupling 5.3.2 Prism coupling 5.4 Index profile determination 5.4.1 WKB approximation for a graded index profile 5.4.2 Ion implanted optical barrier waveguides 5.4.3 Reflectivity calculation method (RCM) 5.4.4 Index profile characterisation 5.4.5 Examples of refractive index profile fitted by usin
X 5.4.6 5.5 5.5.1 5.5.2 Thin film reflectivity method Planar waveguide attenuation Prism methods Insertion loss 6 Ion implanted optical waveguides 6.1 Practical waveguide structures 6.1.1 Conventional fabrication methods 6.1.2 Fabrication by ion implantation structural effects 6.1.3 Chemically formed ion implanted waveguides 6.2 Summary of effects of ion implantation on index 6.3 Materials exhibiting index changes 6.4 Crystalline quartz 6.5 Niobates 6.5.1 Lithium niobate 6.5.2 Optical damage in lithium niobate 6.5.3 Other niobates 6.6 Tantalates 6.7 Bismuth germanate 6.8 Laser hosts 6.8.1 Garnets 6.8.2 Other laser substrates 6.9 Non-linear materials 6.10 Other crystalline materials 6.11 Non-crystalline materials 6.12 Combination with conventional techniques 6.13 Ion implanted chemical waveguides 6.14 Summary of progress so far 7 7.1 7.1.1 7.1.2 7.1.3 7.2 7.2.1 7.2.2 7.2.3 7.3 7.3.1 Applications of ion implanted waveguides Waveguide construction techniques Channel waveguides Optical writing Double barrier implants Ion implanted waveguide lasers Spectroscopic effects Planar waveguide laser performance Channel waveguide lasers Frequency doubling Quartz 183 189 190 192 194 196 197 197 198 200 201 202 202 207 207 213 215 217 219 222 222 226 228 232 233 238 238 241 242 247 248 248 251 253 255 259 260 263 264 265
xi 7.3.2 Potassium niobate 266 7.3.3 Potassium titanyl phosphate 270 7.4 Photorefractive effects 272 7.5 Future and related applications 275 277 Index 279