Molecular Beam Mass Spectrometry System for Characterization of Thermal Plasma Chemical Vapor Deposition

Park, Soonam; Liao, Feng; Larson, J.M.; Girshick, Steven L.; Zachariah, Michael R.

doi:10.1007/s11090-004-2273-1

Cited by 10 publications

(9 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TIMS can also be used for the detection of metastable particles such as N 2 (A 3 + u ) [61] or O 2 (a 1 g ) [62]. Many reports of TIMS of radicals can be found in the literature for fluorocarbon [33,63], oxygen [21,64], chlorine [65], silane [66][67][68][69] or hydrocarbon [34, 35, 66-68, 70, 71] plasmas.…”

Section: Measurement Of Short-lived Reactive Neutral Speciesmentioning

confidence: 99%

Quadrupole mass spectrometry of reactive plasmas

Benedikt¹,

Hecimovic²,

Ellerweg³

et al. 2012

J. Phys. D: Appl. Phys.

100

View full text Add to dashboard Cite

Reactive plasmas are highly valued for their ability to produce large amounts of reactive radicals and of energetic ions bombarding surrounding surfaces. The non-equilibrium electron driven plasma chemistry is utilized in many applications such as anisotropic etching or deposition of thin films of high-quality materials with unique properties. However, the non-equilibrium character and the high power densities make plasmas very complex and hard to understand. Mass spectrometry (MS) is a very versatile diagnostic method, which has, therefore, a prominent role in the characterization of reactive plasmas. It can access almost all plasma generated species: stable gas-phase products, reactive radicals, positive and negative ions or even internally excited species such as metastables. It can provide absolute densities of neutral particles or energy distribution functions of energetic ions. In particular, plasmas with a rich chemistry, such as hydrocarbon plasmas, could not be understood without MS. This review focuses on quadrupole MS with an electron impact ionization ion source as the most common MS technique applied in plasma analysis. Necessary information for the understanding of this diagnostic and its application and for the proper design and calibration procedure of an MS diagnostic system for quantitative plasma analysis is provided. Important differences between measurements of neutral particles and energetic ions and between the analysis of low pressure and atmospheric pressure plasmas are described and discussed in detail. Moreover, MS-measured ion energy distribution functions in different discharges are discussed and the ability of MS to analyse these distribution functions with time resolution of several microseconds is presented.

show abstract

Section: Measurement Of Short-lived Reactive Neutral Speciesmentioning

confidence: 99%

Quadrupole mass spectrometry of reactive plasmas

Benedikt¹,

Hecimovic²,

Ellerweg³

et al. 2012

J. Phys. D: Appl. Phys.

100

View full text Add to dashboard Cite

show abstract

“…The integrated energy enables us to plot and compare concentration profiles for ions of similar masses. However, relative ion concentration profile can only be obtained after the overall mass discrimination of the system is measured 14 . The overall mass discrimination of the present MBMS system with quadrupole mass spectrometer depends on two factors, transmission efficiency and enrichment factor 14 .…”

Section: Resultsmentioning

confidence: 99%

“…However, relative ion concentration profile can only be obtained after the overall mass discrimination of the system is measured 14 . The overall mass discrimination of the present MBMS system with quadrupole mass spectrometer depends on two factors, transmission efficiency and enrichment factor 14 . The transmission efficiency of the quadrupole detector varies with mass such that quadrupoles typically have higher transmission efficiency for lower mass ions.…”

Section: Resultsmentioning

confidence: 99%

Ion Measurements in Premixed Methane-Oxygen Flames

Alquaity¹,

Hourani²,

Chahine³

et al. 2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

View full text Add to dashboard Cite

Ions are formed as a result of chemi-ionization processes in combustion systems. Recently, there has been an increasing interest in understanding flame ion chemistry due to the possible application of external electric fields to reduce emissions and improve combustion efficiency by active control of combustion process. In order to predict the effect of external electric fields on combustion plasma, it is critical to gain a good understanding of the flame ion chemistry. In this work, a Molecular Beam Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry on equivalence ratio of premixed flames. The relative ion concentration profiles are compared qualitatively with previous methane-oxygen studies and show good agreement. The relative ion concentration data obtained in the present study can be used to validate and improve ion chemistry models for methane-oxygen flames.

show abstract

“…In MBMS, the plasma composition is measured by sampling a gas through a small orifice into a differentially pumped vacuum system ͑usually with two or three pumping stages͒ containing a mass spectrometer ͑MS͒. [1][2][3][4][5] The sampling orifice is in line of sight with the ionizer of the MS and therefore even reactive species with high surface reactivity can be detected. MBMS provides, when properly designed and calibrated, absolute densities; a very important information for the identification of growth precursors.…”

Section: Molecular Beam Sampling System With Very High Beam-to-backgrmentioning

confidence: 99%

Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

Benedikt¹,

Ellerweg²,

Keudell³

2009

Review of Scientific Instruments

View full text Add to dashboard Cite

A novel method of reducing the background pressure in a vacuum system used for sampling a molecular beam from a high pressure region is presented. A triple differential pumping stage is constructed with a chopper with rotating skimmer within the first pumping stage, which serves effectively as a valve separating periodically the vacuum system from the ambient environment. The mass spectrometry measurement of the species in the molecular beam show an excellent beam-to-background ratio of 14 and a detection limit below 1 ppm. The potential of this method for detection of low density reactive species in atmospheric pressure plasmas is demonstrated for the detection of oxygen atoms generated in an atmospheric pressure microplasma source.

show abstract

Molecular Beam Mass Spectrometry System for Characterization of Thermal Plasma Chemical Vapor Deposition

Cited by 10 publications

References 18 publications

Quadrupole mass spectrometry of reactive plasmas

Quadrupole mass spectrometry of reactive plasmas

Ion Measurements in Premixed Methane-Oxygen Flames

Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

Contact Info

Product

Resources

About