Application of mid-infrared tuneable diode laser absorption spectroscopy to plasma diagnostics: a review

Within the last decade mid-infrared absorption spectroscopy over a region from 3 to 17?m and based on tuneable lead salt diode lasers, often called tuneable diode laser absorption spectroscopy or TDLAS, has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry in molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has led to further applications of TDLAS because most of these compounds and their decomposition products are infrared active. TDLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetic phenomena. Information about gas temperature and population densities can also be derived from TDLAS measurements. A variety of free radicals and molecular ions have been detected by TDLAS. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of quantum cascade lasers (QCLs) offers an attractive new option for the monitoring and control of industrial plasma processes. The aim of the present paper is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas, (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid-infrared.

[1]  Enric Bertran,et al.  Plasma-enhanced chemical vapor deposition of boron nitride thin films from B2H6–H2–NH3 and B2H6–N2 gas mixtures , 1998 .

[2]  D. Gruen,et al.  Deposition and characterization of nanocrystalline diamond films , 1994 .

[3]  H. Toyoda,et al.  Appearance mass spectrometry of neutral radicals in radio frequency plasmas , 1992 .

[4]  M. Zahniser,et al.  Sub-part-per-billion detection of nitric oxide in air using a thermoelectrically cooled mid-infrared quantum cascade laser spectrometer , 2002 .

[5]  T. Hattori,et al.  Effect of Rare Gas Dilution on CH3 Radical Density in RF-Discharge CH4 Plasma , 1993 .

[6]  G. Kroesen,et al.  In situ infrared absorption spectroscopy of dusty plasmas , 1996 .

[7]  D. Tafalla,et al.  LETTER TO THE EDITOR: Suppression of hydrogenated carbon film deposition by scavenger techniques and their application to the tritium inventory control of fusion devices , 2002 .

[8]  Michael J. Pilling,et al.  Study of the recombination reaction methyl + methyl .fwdarw. ethane. 1. Experiment , 1988 .

[9]  D. Romanini,et al.  CW cavity ring down spectroscopy , 1997 .

[10]  Time-dependent multi-term approximation of the velocity distribution in the temporal relaxation of plasma electrons , 1996 .

[11]  Kevin K. Lehmann,et al.  Ring-down cavity absorption spectroscopy of the very weak HCN overtone bands with six, seven, and eight stretching quanta , 1993 .

[12]  Y. Nakayama,et al.  Growth of amorphous hydrogenated carbon nitride films in radio-frequency plasma , 1999 .

[13]  B. Penetrante,et al.  Identification of mechanisms for decomposition of air pollutants by non-thermal plasma processing , 1997 .

[14]  R. Singer,et al.  Dependence of the growth rate, quality, and morphology of diamond coatings on the pressure during the CVD-process in an industrial hot-filament plant , 2002 .

[15]  C. Hollenstein,et al.  Diborane nitrogen/ammonia plasma chemistry investigated by infrared absorption spectroscopy , 2000 .

[16]  B. Penetrante,et al.  Non-Thermal Plasma Techniques for Pollution Control , 1993 .

[17]  J. Lawler,et al.  Absolute radical density measurements in a CH4H2 d.c. discharge , 1994 .

[18]  J. Röpcke,et al.  Infrared laser spectrum of the fundamental band of the boron monoxide free radical , 2001 .

[19]  P. Coll,et al.  Organic chemistry in Titan's atmosphere: new data from laboratory simulations at low temperature. , 1995, Advances in space research : the official journal of the Committee on Space Research.

[20]  H. Soltwisch,et al.  Infrared diode laser absorption spectroscopy of C(2)H(2) and C(2)H(6) in capacitively coupled methane RF discharges. , 2004, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[21]  J. Röpcke,et al.  On the spectroscopic detection of neutral species in a low-pressure plasma containing boron and hydrogen , 2003 .

[22]  J. Röpcke,et al.  Tunable Diode Laser Absorption Studies of Hydrocarbons in RF Plasmas Containing Hexamethyldisiloxane , 2002 .

[23]  N. L. Arthur.  Methyl-radical absorption cross-section at 216.4 nm and rate constant for methyl-radical recombination , 1986 .

[24]  J. Röpcke,et al.  Tunable Diode Laser Diagnostic Studies of H2-Ar-O2 Microwave Plasmas Containing Methane or Methanol , 1999 .

[25]  J. Butler,et al.  Observation of the gas‐phase infrared spectrum of BH3 , 1987 .

[26]  H. Soltwisch,et al.  Experimental investigation of the chemistry in a capacitively coupled hydrocarbon/oxygen radio frequency discharge , 2001 .

[27]  J. Röpcke,et al.  Diagnostic studies of species concentrations in a capacitively coupled RF plasma containing CH4-H2-Ar , 2001 .

[28]  P. Bernath,et al.  Fourier transform jet emission spectroscopy of the B2Σ+-X2Σ+ transition of CN , 1992 .

[29]  J. Lawler,et al.  Detection of CH3 during CVD Growth of Diamond by Optical Absorption , 1992 .

[30]  P. Gonon,et al.  Chemical vapor deposition of B‐doped polycrystalline diamond films: Growth rate and incorporation efficiency of dopants , 1995 .

[31]  E. Hirota,et al.  The transition dipole moment of the ν2 band of the methyl radical , 1983 .

[32]  M. D'Olieslaeger,et al.  Correlation between the OES plasma composition and the diamond film properties during microwave PA-CVD with nitrogen addition , 1999 .

[33]  de A Ariël Graaf,et al.  Investigation of processes in low-pressure expanding thermal plasmas used for carbon nitride deposition: II. Ar/N2 plasma with graphite nozzle , 2001 .

[34]  S. Bugaev,et al.  Plasma-Chemical Conversion of Lower Alkanes with Stimulated Condensation of Incomplete Oxidation Products , 1998 .

[35]  Richard N. Zare,et al.  Methyl radical measurement by cavity ring-down spectroscopy , 1995 .

[36]  J. Maier,et al.  Cavity ringdown spectroscopy of molecular ions: A2Πu ← X2Σg+ (6−0) transition of N2+ , 1996 .

[37]  R. Zare,et al.  Spatially resolved measurements of absolute CH3 concentration in a hot-filament reactor , 1997 .

[38]  J. Wormhoudt,et al.  A measurement of the strength of the ν2 band of CH3 , 1989 .

[39]  M. Pilling,et al.  Determination of the absorption cross section for methyl at 216.36 nm and the absolute rate constant for methyl radical recombination over the temperature range 296-577 K , 1985 .

[40]  de A Ariël Graaf,et al.  Investigation of processes in low-pressure expanding thermal plasmas used for carbon nitride deposition: I. Ar/N2/C2H2 plasma , 2001 .

[41]  David M. Wardlaw,et al.  Study of the recombination reaction methyl + methyl .fwdarw. ethane. 2. Theory , 1988 .

[42]  T. Yamamoto,et al.  VOC decomposition by nonthermal plasma processing — a new approach☆ , 1997 .

[43]  KoHse-HoingHaus.  Applied Combustion Diagnostics , 2002 .

[44]  P. Martineau,et al.  Infrared diode laser diagnostics of methane plasmas produced in a deposition reactor , 1990 .

[45]  G. Turban,et al.  Mass spectrometric investigations on plasmas obtained from a dual electron cyclotron resonance-radio frequency discharge , 1998 .

[46]  H. Kojima,et al.  Spatial distribution of CH3 and CH2 radicals in a methane rf discharge , 1990 .

[47]  T. Encrenaz,et al.  Detection of the Methyl Radical on Neptune , 1999 .

[48]  M. Fraser,et al.  Ambient formaldehyde detection with a laser spectrometer based on difference-frequency generation in PPLN , 2001, Applied physics. B, Lasers and optics.

[49]  G. Turban,et al.  Growth, microstructure and electronic properties of amorphous carbon nitride films investigated by plasma diagnostics , 1999 .

[50]  J. Wormhoudt,et al.  Radical and molecular product concentration measurements in CF4 and CH4 radio frequency plasmas by infrared tunable diode laser absorption , 1990 .

[51]  G. Kroesen,et al.  Production and destruction of CFx radicals in radio‐frequency fluorocarbon plasmas , 1996 .

[52]  G. Kroesen,et al.  Measurements of radical densities in radio‐frequency fluorocarbon plasmas using infrared absorption spectroscopy , 1994 .

[53]  M. Zarcone,et al.  Electron distribution functions in laser fields , 2001 .

[54]  F. Raulin,et al.  Experimental simulation of Titan's organic chemistry at low temperature. , 1995, Planetary and space science.

[55]  R. McAdams,et al.  Prospects for non-thermal atmospheric plasmas for pollution abatement , 2001 .

[56]  Raymond W. Walker,et al.  Evaluated kinetic data for combustion modelling supplement I , 1994 .

[57]  Frank K. Tittel,et al.  Mid-Infrared Laser Applications in Spectroscopy , 2003 .

[58]  M. Nesladek,et al.  Optical emission spectroscopy of the plasma during microwave CVD of diamond thin films with nitrogen addition and relation to the thin film morphology , 1997 .

[59]  M. Pilling,et al.  The pressure and temperature dependence of the rate constant for methyl radical recombination over the temperature range 296–577 K , 1983 .

[60]  Paul B. Davies,et al.  Diode laser spectroscopy and coupled analysis of the ν2 and ν4 fundamental bands of SiH+3 , 1994 .

[61]  J. Lawler,et al.  Methyl radical production in a hot filament CVD system , 1993 .

[62]  J. Röpcke,et al.  Quantitative detection of methyl radicals in non-equilibrium plasmas: a comparative study , 2004 .

[63]  T. Hattori,et al.  H 2 Partial Pressure Dependences of CH 3 Radical Density and Effects of H 2 Dilution on Carbon Thin-Film Formation in RF Discharge CH 4 Plasma , 1995 .

[64]  J. Röpcke,et al.  Study of an H2/CH4 moderate pressure microwave plasma used for diamond deposition: modelling and IR tuneable diode laser diagnostic , 2005 .

[65]  M. Zahniser,et al.  TOBI: A two-laser beam infrared system for time-resolved plasma diagnostics of infrared active compounds , 2003 .

[66]  T. Hattori,et al.  Correlation between CH3 Radical Density and Carbon Thin-Film Formation in RF Discharge CH4 Plasma , 1994 .

[67]  J B McManus,et al.  Astigmatic mirror multipass absorption cells for long-path-length spectroscopy. , 1995, Applied optics.

[68]  P. Davies,et al.  Infrared laser spectroscopy of the A 2Πu←X 2Σ+g system of the Si−2 anion , 1996 .

[69]  E. Filimonova,et al.  Comparative modelling of NOx and SO2 removal from pollutant gases using pulsed-corona and silent discharges , 2000 .

[70]  J. Röpcke,et al.  On NOx production and volatile organic compound removal in a pulsed microwave discharge in air , 2005 .

[71]  J. Lawler,et al.  Evaluation of a substrate pretreatment for hot filament CVD of diamond , 1994 .

[72]  T. Fujii,et al.  Diagnosis of a CH4/N2 Microwave Discharge: Ionic and Neutral Species , 2000 .

[73]  Vibration-rotation spectrum of BH X1Σ+ by Fourier transform emission spectroscopy , 1988 .

[74]  John U. White.  Long Optical Paths of Large Aperture , 1942 .

[75]  W. Demtröder.  Laser Spectroscopy: Basic Concepts and Instrumentation , 1996 .

[76]  Daniele Romanini,et al.  Measurement of density in a discharge by intracavity laser absorption spectroscopy and CW cavity ring-down spectroscopy , 1998 .

[77]  G. Kroesen,et al.  Measurement of the gas temperature in fluorocarbon radio frequency discharges using infrared absorption spectroscopy , 1996 .

[78]  Hunt,et al.  Infrared Diode Laser Spectrum of the nu(1) Fundamental Band of ClBO. , 2000, Journal of Molecular Spectroscopy.

[79]  J. A. Coxon,et al.  Rotational Analysis of the A2Π → X2Σ+ visible band system of boron monoxide, BO , 1984 .

[80]  M. Heaven,et al.  Laser-induced fluorescence of the BO and BO2 free radicals , 1980 .

[81]  A. B. Callear.  Oscillator strengths of the bands of the B2 A'1---X2 A , 1976 .

[82]  M. Hori,et al.  CH3 Radical Density in Electron Cyclotron Resonance CH3OH and CH3OH/H2 Plasmas , 1995 .

[83]  R. Zare,et al.  Measurement of the methyl radical concentration profile in a hot‐filament reactor , 1995 .

[84]  E. M. Veldhuizen,et al.  Electrical discharges for environmental purposes : fundamentals and applications , 2000 .

[85]  M. Quack,et al.  High temperature UV absorption and recombination of methyl radicals in shock waves , 1977 .

[86]  R. Dillon,et al.  Tunable diode laser spectroscopy measurement of CH3 and C2H2 densities in a H2O/CH3OH radio frequency chemical vapor deposition diamond system , 1997 .

[87]  S. Lucidi,et al.  Automatic optimization strategy for the design of circular multipolar magnets , 2001 .

[88]  M. Hori,et al.  Synthesis of Diamond Using RF Magnetron Methanol Plasma Chemical Vapor Deposition Assisted by Hydrogen Radical Injection , 1995 .

[89]  M. Zahniser,et al.  IRMA: A tunable infrared multicomponent acquisition system for plasma diagnostics , 2000 .

[90]  J. Röpcke,et al.  Line strengths and transition dipole moment of the nu2 fundamental band of the methyl radical. , 2005, The Journal of chemical physics.

[91]  J. Röpcke,et al.  Modeling of microwave discharges of H2 admixed with CH4 for diamond deposition , 2005 .

[92]  Ronald K. Hanson,et al.  A cw laser absorption diagnostic for methyl radicals , 1993 .

[93]  F. Tittel,et al.  Portable fiber-coupled diode-laser-based sensor for multiple trace gas detection , 1999, Applied physics. B, Lasers and optics.

[94]  Hiroshi Ito,et al.  Effects of H, OH, and CH3 radicals on diamond film formation in parallel-plate radio frequency plasma reactor , 1997 .

[95]  T. Ichiki,et al.  Effects of the substrate bias on the formation of cubic boron nitride by inductively coupled plasma enhanced chemical vapor deposition , 1994 .

[96]  M. Hannemann,et al.  On the Ions in an Argon-Hexamethyldisiloxane Radio-Frequency-Discharge , 1994 .

[97]  Phelps,et al.  Anisotropic scattering of electrons by N2 and its effect on electron transport. , 1985, Physical review. A, General physics.

[98]  R. S. Mulliken.  The Isotope Effect in Band Spectra, II: The Spectrum of Boron Monoxide , 1925 .

[99]  N. Mutsukura.  Deposition of Diamondlike Carbon Film and Mass Spectrometry Measurement in CH4/N2 RF Plasma , 2001 .

[100]  Omar Elmazria,et al.  Surface acoustic wave devices based on nanocrystalline diamond and aluminium nitride , 2003 .

[101]  Wen-Jhy Lee,et al.  Converting Methane by Using an RF Plasma Reactor , 1998 .

[102]  P. Davies,et al.  Diode laser spectroscopy of 10B16O and 11B16O boron monoxide (X2Σ , 2004 .

[103]  V. Bondybey,et al.  Fourier transform UV, visible, and infrared spectra of supersonically cooled CN radical , 1992 .

[104]  A. V. Phelps,et al.  Vibrational excitation of D2 by low energy electrons , 1985 .

[105]  J. Röpcke,et al.  A DIODE LASER AND MODELING STUDY OF MIXED (CH4-H2-O2) AC PLASMAS , 1999 .

[106]  A. Wrobel.  3 – Plasma-Polymerized Organosilicones and Organometallics , 1990 .

[107]  P. Martineau,et al.  Diagnostics and modeling of silane and methane plasma CVD processes , 1992 .

[108]  J. Röpcke,et al.  On the hydrocarbon chemistry in a H2 surface wave discharge containing methane , 2001 .

[109]  S. Baughcum,et al.  Real-time detection of methyl radicals by diode laser absorption at 608 cm−1☆ , 1982 .

[110]  J. Röpcke,et al.  Diagnostic studies of H2?Ar?N2 microwave plasmas containing methane or methanol using tunable infrared diode laser absorption spectroscopy , 2003 .

[111]  J. Röpcke,et al.  A time resolved laser study of hydrocarbon chemistry in H2-CH4 surface wave plasmas , 2001 .

[112]  Geoffrey Duxbury.  Infrared Vibration-Rotation Spectroscopy: From Free Radicals to the Infrared Sky , 2000 .

[113]  J. Röpcke,et al.  Comparison of optical emission spectrometric measurements of the concentration and energy of species in low-pressure microwave and radiofrequency plasma sources , 1993 .

[114]  W. A. Payne,et al.  Rate Constant for the Recombination Reaction CH3 + CH3 → C2H6 at T = 298 and 202 K. , 2002, The journal of physical chemistry. A.

[115]  P. Martineau,et al.  Infrared laser diagnostics in methane chemical‐vapor‐deposition plasmas , 1992 .

[116]  J. Röpcke,et al.  Diode laser spectroscopy of the fundamental bands of 12C14N, 13C14N, 12C15N, 13C15N free radicals in the ground 2 Sigma+ electronic state. , 2005, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[117]  T. Ichiki,et al.  Preparation of cubic boron nitride films by low pressure inductively coupled plasma enhanced chemical vapor deposition , 1994 .

[118]  J. Albella,et al.  Deposition of diamond and boron nitride films by plasma chemical vapour deposition , 1995 .

[119]  I. Dubois,et al.  The A-X and B-X transitions of BO , 1985 .

[120]  J. Röpcke,et al.  Spectroscopic diagnostics and modeling of Ar∕H2∕CH4 microwave discharges used for nanocrystalline diamond deposition , 2004 .