Front Cover -- Handbook of Silicon Based MEMS Materials and Technologies -- Copyright Page -- Contents -- List of contributors -- Preface -- Where is silicon based MEMS heading to? -- References -- I. Silicon as MEMS Material -- 1 Properties of silicon -- 1.1 Properties of silicon -- 1.1.1 Crystallography of silicon -- 1.1.1.1 Miller index (hkl) system -- 1.1.1.2 Stereographic projection -- 1.1.2 Defects in silicon lattice -- 1.1.3 Mechanical properties of silicon -- 1.1.4 Electrical properties -- 1.1.4.1 Introduction-dopants and impurities in silicon
1.1.4.2 Piezoresistive effect in silicon -- General piezoresistive effect -- Strain -- Stress in anisotropic materials -- Strain effect on resistivity -- Linearity -- Effect of temperature and doping -- Example of a piezoresistive sensor design -- Surface effects -- References -- 2 Czochralski growth of silicon crystals -- 2.1 The Czochralski crystal-growing furnace -- 2.1.1 Crucible -- 2.1.2 Hot zone materials -- 2.1.3 Hot zone structure -- 2.1.4 Gas flow -- 2.2 Stages of growth process -- 2.2.1 Melting -- 2.2.2 Neck -- 2.2.3 Crown -- 2.2.4 Body -- 2.2.5 Tail -- 2.2.6 Shut-off
2.3 Selected issues of crystal growth -- 2.3.1 Diameter control -- 2.3.2 Doping -- 2.3.3 Hot zone lifetime -- 2.4 Improved thermal and gas-flow designs -- 2.5 Heat transfer -- 2.6 Melt convection -- 2.6.1 Free convection -- 2.6.2 Crucible rotation -- 2.6.3 Crystal rotation -- 2.6.4 Marangoni convection and gas shear -- 2.7 Magnetic fields -- 2.7.1 Cusp field -- 2.7.2 Transverse field -- 2.7.3 Melt flows under transverse field -- 2.7.4 Time-dependent fields -- 2.8 Hot recharging and continuous feed -- 2.8.1 Hot recharging -- 2.8.2 Charge topping -- 2.8.3 Crucible modifications
2.8.4 Continuous Czochralski growth -- 2.9 Heavily n-type doped silicon and constitutional supercooling -- 2.9.1 Constitutional supercooling -- 2.9.2 Melting-point depression -- 2.9.3 Origin of dopant gradient in the melt -- 2.9.4 Path to lower resistivity -- 2.10 Growth of large diameter crystals -- 2.10.1 Neck growth for large crystals -- 2.10.2 Neck extension -- 2.10.3 Additional stresses on neck -- 2.10.4 Dislocations oriented in (100) direction in large diameter crystals -- 2.10.5 Crucible wall temperature -- 2.10.6 Double-layered crucible structure -- 2.10.7 Crucible deformations
2.10.8 Intentional devitrification -- 2.10.9 Transverse or cusp field for very large crystals -- 2.10.10 Boosting crystal weight -- 2.10.11 Seed chuck -- 2.10.12 Additional challenges -- References -- Further reading -- 3 Properties of silicon crystals -- 3.1 Dopants and impurities -- 3.2 Typical impurity concentrations -- 3.3 Concentration of dopants and impurities in axial direction -- 3.4 Resistivity -- 3.5 Radial variation of impurities and resistivity -- 3.6 Thermal donors -- 3.7 Defects in silicon crystals
