Diagnostics and modeling of an inductively coupled radio frequency discharge in hydrogen [Elektronische Ressource] / von Victor Anatolievich Kadetov

Kadetov

Sujets

• Physik

Informations

• Publié par: ruhr-universitat_bochum
• Publié le: 01 janvier 2004
• Nombre de lectures: 26
• Langue: English
• Poids de l'ouvrage: 13 Mo

Extrait

Diagnostics and modeling of
an inductively coupled
radio frequency discharge in hydrogen

Dissertation
zur
Erlangung des Grades eines
Doktors der Naturwissenschaften
in der
Fakultät für Physik und Astronomie
der Ruhr-Universität Bochum

von
Victor Anatolievich Kadetov
aus Moskau


Dissertation eingereicht am: 10.05.2004.
Tag der mündlichen Prüfung: 19.06.2004.
Referent: Prof. Dr. rer. nat. Uwe Czarnezki
Korreferent: Prof. Dr. rer. nat. Ralf Peter Brinkmann



Bochum 2004 Contents

1. Introduction..................................................................................5
2. Brief review on ICPs ....................................................................8
3. Fundamentals .............................................................................11
3.1. RF discharge basics11
3.1.1. Plasma generation in RF discharges ............................................................11
3.1.2. RF discharges classification ..........................................................................13
3.1.3. CCP discharges ..............................................................................................14
3.1.4. ICP discharges................................................................................................17
3.2. Diagnostic tools....................................................................................24
3.2.1. Langmuir probe .............................................................................................24
3.2.2. Fluorescence-dip spectroscopy .....................................................................27
3.2.3. Ion energy and mass analyzer.......................................................................29
3.2.4. Emission Spectroscopy ..................................................................................31
4. Theory .........................................................................................34
4.1. Analytical model of a hydrogen plasma............................................35
4.1.1. Profiles of plasma potential and plasma density (relative values).............36
4.1.2. Electron temperature.....................................................................................38
4.1.3. Energy balance...............................................................................................40
4.1.4. Plasma density (absolute values) ..................................................................43
4.2. Electrical model of an ICP source .....................................................44
4.2.1 Plasma configuration in a planar ICP .........................................................44
4.2.2 Set of equations for the transformer model.................................................47
4.2.3 Modeling an ICP source ................................................................................50
4.2.4 The efficiency of the GEC reference cell as a hydrogen plasma source ...57
4.2.5 Modification of the antenna design ..............................................................58
4.2.6 The modified plasma source .........................................................................63
4.3. Sheath theory .......................................................................................65
4.3.1. Static sheath....................................................................................................65
4.3.2. Sheath in ICP .................................................................................................67
4.3.3. Ion energy distribution..................................................................................72
5. Experimental setup ....................................................................75
2 5.1. Plasma source ......................................................................................75
5.1.1. ICP setup.........................................................................................................75
5.1.2. ICP source characterization..........................................................................77
5.2. Diagnostics ...........................................................................................79
5.2.1. Langmuir probe measurements....................................................................79
5.2.2. Laser diagnostics............................................................................................80
5.2.3. Measurement of ion energies ........................................................................83
5.2.4. Optical measurements ...................................................................................86
6. Results .........................................................................................87
6.1. Gas Temperature.................................................................................87
6.1.1. Doppler broadening.......................................................................................87
6.1.2. Gas temperature of a hydrogen ICP ............................................................88
6.2. Plasma bulk parameters .....................................................................89
6.2.1. Electron energy distribution function..........................................................89
6.2.2. Electron temperature.....................................................................................90
6.2.3. Plasma density................................................................................................93
6.3. Sheath dynamics..................................................................................95
6.3.1. Electric field in the ICP sheath.....................................................................95
6.3.2. Time-averaged electric field..........................................................................95
6.3.3. Time-varied electric field in the sheath........................................................98
6.3.4. Sheath parameters .......................................................................................100
6.4. Ion Energy Distribution functions...................................................102
6.4.1. Energy distribution of the ion flux .............................................................102
6.4.2. Electron temperature at the sheath edge106
6.4.3. Plasma potential...........................................................................................107
6.5. CCP-ICP mode transition ................................................................108
6.5.1. ICP emission.................................................................................................108
6.5.2. Intensity modulation....................................................................................110
6.5.3. Mode transition ............................................................................................110
6.5.4. Mode transition in the pulsed ICP .............................................................112
7. Summary and conclusions.......................................................114
Appendix A List of symbols and abbreviations..........................117
Appendix B Analytical model of a hydrogen plasma..................122
B.1. Particle transport equations.............................................................123
3B.1.1. Diffusion approximation .............................................................................124
B.2. Energy transport equation ...............................................................124
B.2.1. Elementary processes in a hydrogen plasma.............................................124
B.2.2. Energy loss due to a particle transport......................................................125
B.2.3. Ohmic heating ..............................................................................................125
B.2.4. The average density and the density at the sheath edge...........................126
B.2.5. Local energy balance and induced electric field .......................................127
B.3. One-dimensional model ....................................................................128
B.3.1. Set of dimensionless variables.....................................................................128
B.3.2. Particle transport equations........................................................................129
B.3.3. Profiles of plasma potential and plasma density (relative values)...........129
B.3.4. Electron temperature...................................................................................130
B.4. Spatially resolved model in the diffusion approximation..............132
B.4.1. Plasma density in the entire discharge volume .........................................132
B.5. Absolute value of the plasma density ..............................................133
Appendix C Transformer model..................................................134
C.1. Inductive power coupling into the plasma......................................134
C.1.1. Structure of an electromagnetic field induced in a vacuum ....................134
C.1.2. Antenna-plasma transformer .....................................................................136
C.1.3. Antenna inductance and transformer impedance