Appendix A Definitions and Symbols
A.1 Symbols and Conversion Factors
A absorptivity a distance aperture b net increase in number of molecules per formula unit; b = μ − 1 C constant C Euler’s constant; C = 0.577 Cp heat capacity c speed of light; c = 2.998 ×1010 cm/s cp specific heat at constant pressure [J/gK, J/molK] cv specific heat at constant volume [J/gK, J/molK] D heat diffusivity [cm2/s] transmittivity 2 Di molecular diffusion coefficient of species i [cm /s] d lateral width of laser-processed features [μm, cm] diameter E electric field [V/cm] energy [J] −2 kBT (T = 273.15 K) = 2.354 ×10 eV 1 kcal/mol =# 0.043 eV =# 5.035 ×102 K 1eV=# 1.1604 ×104 K =# 1.602 ×10−19 J 1 kcal =# 4.187 ×103 J 1cm−1 =# 1.24 ×10−4 eV =# 1.439 K 1J=# 2.39 ×10−4 kcal EF Fermi energy E activation temperature [K]; E = E/kB E ∗ normalized activation temperature; E ∗ = E /T (∞) E activation energy [eV; kcal/mol] Em activation energy for melting Ev activation energy for vaporization at Tb
D. Bäuerle, Laser Processing and Chemistry, 4th ed., 739 DOI 10.1007/978-3-642-17613-5, C Springer-Verlag Berlin Heidelberg 2011 740 Appendix A
Eg bandgap energy = energy distance between (lowest) conduction and (highest) valence bands E laser-pulse energy [J] e elementary charge; e = 1.602 ×10−19 C ee≈ 2.718 eV electron Volt 1eV/particle = 23.04 kcal/mol F area Faraday constant; F = 96485 C/mol f focal length [cm] Gr Grashof number G Gibbs free energy g acceleration due to gravity gT temperature discontinuity coefficient H total enthalpy [J/cm3,J/g, J/mol] reaction enthalpy H a [J/atom]= H [J/cm3]·M/ρL = H [J/g]·M/L = H [J/mol]/L Hv heat of vaporization at Tb Hm heat of melting Ht total latent heat Ht = Hm + Hv h Planck’s constant; h = 6.626 ×10−34 Js ◦ height, thickness or depth of laser-processed patterns [A, μm] h1 thickness of single evaporated or sputtered layer on a substrate hi thickness of layer i on a substrate hl thickness of a liquid layer, or an adsorbate hs thickness of slab or substrate h change in layer thickness ◦ ablated layer thickness per pulse [A/pulse] hν photon energy hν[eV]≈1240/λ[nm] I intensity [W/cm2] Ia absorbed laser-light intensity Ith threshold intensity Iv evaporation intensity J flux 2 Ji flux of species i [species/cm s] j current density K force k kinetic (rate) constant k0 pre-exponential factor −23 kB Boltzmann constant; kB = 1.381 ×10 Ws/K rec ki recombination constant for species i k wavevector of laser radiation kT thermal diffusion ratio Appendix A 741
L Avogadro number (Loschmidt number); L = 6.022 ×1023 /mol L Langmuir [1 L = 10−6 Torr s] l characteristic length, depth [μm] lT heat-diffusion length [μm] − lα optical penetration depth [μm]; lα = α 1 M molar mass [g/mol] m mass exponent, e.g., in κ(T ) N total number of species (atoms, molecules, electrons, holes, etc.) per volume [cm−3] or per area [cm−2] −3 Ni number of species i per volume [cm ] or per area [cm−2] N number of laser pulses n refractive index (real part) exponent, e.g., in Di (T ) n normal vector nˆ unit vector √ n˜ complex refractive index; n˜ = ε = n + iκa ≡ n(1 + iκ0) P laser power [W] Pa absorbed laser power [W] p total gas pressure [mbar] 1 mbar =# 102 N/m2 =# 102 Pa ≈ 0.750 Torr =# 1.02 ×10−3 at[kp/cm2] =# 9.87 ×10−4 atm 1atm=# 2.688 ×1019[species/cm3] pi partial pressure of species i [mbar] Q source term q exponent, e.g., in equation of state q wavevector R optical (power) reflectivity electrical resistance ["] R sheet resistance ["/] RD optical reflection coefficient of deposited material RG gas constant; RG = 8.314 J/Kmol =# 1.987 cal/Kmol Ra Rayleigh number r radial distance rD radius of deposit S stress oversaturation S Poynting vector energy flux [J/cm2s] s sticking coefficient T temperature [K] Tb boiling temperature Tc center temperature 742 Appendix A
Tg gas-phase temperature Tl temperature within liquid TM temperature within medium Tm melting temperature Ts substrate temperature surface temperature Tst stationary temperature Tth threshold temperature Tv temperature of vapor T (∞) temperature far away from irradiated zone T temperature rise T ∗ normalized temperature, e.g., T/T (∞) t time tv time to reach Tst (Fig. 11.2.2) t time interval tm time of existence of melt on surface V volume [cm3] Vn volume per molecule/atom v velocity [cm/s] mass average velocity vls velocity of liquid–solid interface vvl velocity of vapor–liquid interface v0 sound velocity vs scanning velocity of laser beam or substrate [μm/s] v thermal velocity of gas molecules W reaction rate heterogeneous reactions [number of species/scm2] homogeneous reactions [number of species/scm3] ◦ WA ablation rate [μm/s; A/pulse] ◦ WD deposition rate [μm/s; A/pulse] ◦ WE etch rate [μm/s; A/pulse] Wex excitation rate w radius of laser focus with constant intensity distribution [μm] radius of laser focus at FWHM √ 2 we radius of laser focus (1/e intensity); we = 2w0 w0 radius of laser focus of Gaussian beam (1/e intensity) [μm] w probability width of reaction zone xi molar ratio of species i; xi = Ni /N x, xα set of space coordinates with α = 1, 2, 3, e.g., x, y, z Y Young’s modulus Z number of condensed atoms per molecule z charge of ions in units of e zR Rayleigh length of laser focus [μm] Appendix A 743
α optical absorption coefficient [cm−1] αT thermal diffusion constant β exchange coefficient exponent parameter symmetry factor factor βT coefficient of thermal expansion Γ increment parameter ratio aspect ratio [ratio of depth or height to width]; Γ = h/d γ exponent total reaction order adiabatic index; γ = cp/cv;1<γ ≤ 5/3 real part of increment γi reaction order with respect to species i difference δ delta function parameter ε dielectric constant permittivity spectral emissivity εa apparent emissivity −12 ε0 dielectric constant in vacuum; ε0 = 8.854 ×10 As/Vm εt total emissivity ζ parameter integer factor ζi stoichiometric coefficient of species i η dissociation yield dynamic viscosity [g/cm s]; η = ρνk reaction probability surface conductance [coefficient of surface heat transfer] [W/cm2K] % angle θ linearized temperature θ c center-temperature√ rise for Gaussian beam; θc = π Iaw0/2κ,see(7.1.4) %i coverage by species i ϑ angle κ thermal conductivity [W/cm K]; 1W/mK=# 2.39 ×10−3 cal/cmKs κa absorption index κa = nκ0 κD thermal conductivity of deposit κL, κ1 thermal conductivity of thin layer 744 Appendix A
κM thermal conductivity of medium κs thermal conductivity of substrate κ0 attenuation index Λ parameter spacing function λ wavelength of electromagnetic radiation [nm, μm] λ[nm]≈1240/hν [eV] λm mean free path of molecules [cm] μ factor index integer chemical potential Poisson ratio μ = b + 1 2 μe, μh mobility of electrons and holes [cm /Vs] ν frequency [s−1] index 2 νk kinematic viscosity [cm /s] νr laser-pulse-repetition rate [Hz] ξ overpotential parameter product parameter π 3.14159 ρ electrical resistivity [" cm] 3 mass density [g/cm ] summation sign e.g., a ± b ∓ c ≡ (a + b − c) + (a − b + c) ± σ electrical conductivity [" cm]−1 surface tension [J/cm2] excitation cross section of species [cm2] −12 2 4 σr Stefan–Boltzmann constant; σr = 5.67 ×10 W/cm K τ relaxation time [s] τ laser-pulse duration [s] laser-beam dwell time [s]; τ = 2w/vs τm time for surface melting τT thermal relaxation time [s] Φ electrical potential φ laser fluence [J/cm2] angle φth threshold fluence ϕ angle Appendix A 745
χ magnetic susceptibility parameter Ψ function ψ wave function " total solid angle; " = 4π Ohm d" solid angle [sr] ω angular frequency [s−1]; ω = 2πν ⊥ normal (perpendicular) parallel ∇2 Laplace operator ∇ Nabla operator
A.2 Abbreviations, Acronyms
− acac [CH3COCHCOCH3] = acetylacetonate anion AdGC allyl-diglycol-carbonate AES Auger electron spectroscopy ALE atomic layer epitaxy AM1 sunlight illumination APD ablative photodecomposition BBS barium aluminum borosilicate BK7 boron crown glass CAD computer-aided design CAM computer-aided manufacturing CARS coherent anti-Stokes Raman scattering CBE chemical beam epitaxy CCD charge-coupled device CMR colossal magnetoresistance, same as GMR CPA chirped-pulse amplification CVD chemical vapor deposition DLC diamond-like carbon; dry laser cleaning EAL etching of atomic layers; excimer-laser ablation lithography EB electron beam EBCVD electron-beam-induced chemical vapor deposition EBE electron-beam evaporation EDX energy-dispersive X-ray analysis EELS electron-energy-loss spectroscopy EMF electromotive force ESCA electron spectroscopy for chemical analysis ESR electron spin resonance FEP tetrafluoroethylene-hexafluoropropylene FH fourth harmonic Foturan lithium aluminosilicate glass doped with (photoactive) Ce 746 Appendix A
FWHM full width at half maximum GMR giant magnetoresistance HAZ heat-affected zone − hfacac [CF3COCHCOCF3] = hexafluoroacetylacetonate anion HPDS hexaphenyldisilane HTS high-temperature superconductors HV high vacuum (10−7 < p < 10−3 mbar) IBAD ion-beam assisted deposition IC integrated circuit IR infrared radiation ITO indium tin oxide Kapton polyimide (Du Pont) LA laser annealing LAL laser-ablation lithography LC laser cleaning; liquid crystal LCP laser-induced chemical processing LCVD laser-induced CVD LEC laser-enhanced electrochemistry LEE laser-enhanced electrochemical etching LEED low-energy electron diffraction LEP laser-enhanced electrochemical plating LI laser implantation LID laser-induced desorption LIF laser-induced fluorescence LIFT laser-induced forward transfer LIS laser isotope separation LMBE laser molecular beam epitaxy LPCVD laser-enhanced PCVD LPE laser-enhanced plasma etching LPPC laser-pulsed plasma chemistry LSA laser-surface alloying LSAW laser-supported absorption wave LSCW laser-supported combustion wave LSD laser-sputter deposition LSDW laser-supported detonation wave MALDI matrix-assisted laser desorption ionization MBE molecular beam epitaxy ME metal ML multiline operation of laser monolayer MMA methylmethacrylate MOCVD metal-organic CVD MP multiphoton MPA multiphoton absorption MPD multiphoton dissociation Appendix A 747
MPI multiphoton ionization Mylar same as PET NC nitrocellulose NEP noise equivalent power NIR near IR OMA optical multichannel analyzer PA polyamide PAN polyacrylonitrile PC polycarbonate PCVD plasma CVD PE plasma etching polyethylene PEEK polyetheretherketone PEO polyethylene oxide PES polyethersulfone PET polyethylene-terephthalate (same as Mylar) PI polyimide [Kapton, Upilex] PL photoluminescence PLA pulsed-laser annealing PLD pulsed-laser deposition PLE pulsed-laser evaporation PLPC pulsed-laser plasma chemistry PLZT lanthanum-doped PZT, i.e., Pb1−3y/2LayTi1−x Zrx O3 PMMA polymethyl-methacrylate (Plexiglas) PP polypropylene PPQ poly(phenyl-quinoxaline) pps pulses per second PS polystyrene PSL polystyrene latex PSUL polysulfone PTFE polytetrafluoroethylene (Teflon) PU polyurethane PVAC polyvinylacetate PVC polyvinyl chloride PVDF polyvinylidene fluoride PXE same as PZT (PbTi1−x Zrx O3) Pyrex borosilicate glass (80% SiO2,12%B2O3,3%Al2O3,4%Na2O) PZT lead titanate zirconate PbTi1−x Zrx O3 QCM quartz-crystal microbalance QMS quadrupole mass spectrometer RBS Rutherford backscattering spectroscopy RF radio frequency RHEED reflection high-energy electron diffraction RIE reactive ion etching rms root mean square 748 Appendix A
RTA rapid thermal annealing SAW surface acoustic wave SEM scanning electron microscopy SERS surface-enhanced Raman scattering SEW surface electromagnetic wave SH second harmonic SI semi-insulating SIMS secondary ion mass spectroscopy SLC steam laser cleaning SNOM scanning near-field optical microscopy SOI silicon on insulator SOS silicon on sapphire SQUID superconducting quantum interference device SRR split ring resonator STE self-trapped exciton STED stimulated emission depletion SXM scanning-probe microscopy TEM transmission electron microscopy TEOS tetraethylorthosilicate TFT thin-film transistor TG thermogravimetry TH third harmonic TiBAl Al(C4H9)3 TM trade mark TMVS trimethylvinylsilane TOF time-of-flight UHV ultrahigh-vacuum (p < 10−7 mbar) ULSI ultra-large-scale integrated systems UPS ultraviolet photo-spectroscopy UV ultraviolet radiation VIS visible radiation VLSI very-large-scale integrated systems VUV vacuum UV XAFS X-ray absorption fine structure spectroscopy XPS X-ray photoemission spectroscopy XRD X-ray diffraction YBCO YBa2Cu3O7−δ YSZ 8 mol % Y2O3 stabilized ZrO2 Appendix B Mathematical Functions and Relations
Bessel Function