Atomic mechanisms of stress formation of group IVB-VIB transition metal nitrides deposited by DC magnetron sputtering [Elektronische Ressource] / vorgelegt von Patrick Mwangi Karimi

Patrick Geddes

Sujets

• Physik

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2007
• Nombre de lectures: 26
• Langue: Deutsch
• Poids de l'ouvrage: 2 Mo

Extrait

Atomic Mechanisms of Stress Formation of Group IVB-VIB Transition
Metal Nitrides Deposited by DC Magnetron Sputtering




Von der Fakultät für Mathematik, Informatik und
Naturwissenschaften
der Rheinisch-Westfälischen Technischen Hochshule Aachen
zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften
genehmigte Dissertation



Vorgelegt von



Patrick Mwangi Karimi
(M.Sc.)
aus Kirinyaga, Kenia



Berichter: Herr Uni.-Prof. Dr.rer.nat. Matthias Wuttig
Frau Uni.-Prof. Dr.rer. nat. Heidrun Heinke



Tag der mündlichen Prüfung: 04. Juni 2007


Diese Dissertation ist auf den Internetseiten der Hochschulbiliothek
online verfügbar.






Gedruckt mit Unterstützung des Deutschen Akademischen Austauschdienstes






























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Contents

List of Figures……………………………………………………………………………………………………………..viii
List of Tables……………………………………………………………………................................................................xiv

1 Introduction and motivation.............................................................................................................................1
1.1 Introduction............................................................................................................................................................1
1.2 Motivation................................3
1.3 Thesis outline........................3

2 Theory: Sputtering, growth, structure and stress models ...................................................5
2.1 Sputtering........................................5
2.1.1 DC glow discharge...6
2.1.2 Plasma interactions..................................................................................................................................8
2.1.3 Reactive sputtering...9
2.2 Thin film growth....................10
2.2.1 Thermodynamics.....10
2.2.2 Kinetics............................12
2.2.3 Structure evolution during film deposition......................................................................13
2.3.4 Stress models..............15
2.3.4.1 Tensile Stresses .....................................................................................................................16
2.3.4.2 Compressive stresses........................................................................................................17
2.3.4.3 Structure and stress in group IVB-VIB metal oxides ..........................18

3 Theory: Characterization techniques...................................................................................................21
3.1 X-ray Diffraction..................................................................................................................................................21
3.1.1 Bragg’s equation......23
3.1.2 Texture: Grain orientation..............................................................................................................26
3.2 X-ray reflectometry.............27
iii
3.3 Rutherford backscattering spectroscopy (RBS)........................................................................30
3.3.1 Rutherford backscattering cross-section and yield...................................................32
3.4 Mechanical Properties .....................................................................................................................................33
3.4.1 Stress: Definition.....33
3.4.2 Stress in three dimension ................................................................................................................34
23.4.3 Stress measurement by x-ray diffraction (sin ψ method)...................................38
3.4.4 Wafer curvature methods40
3.5 Optical properties using ellipsometry ................................................................................................43
3.5.1 Optical constants ....................................................................................................................................46

4 Experimental procedures....49
4.1 Film deposition.......................49
4.2 X-ray Diffraction experiments .................................................................................................................51
4.2.1 Bragg-Brentano geometry (BB)................................................................................................51
4.2.2 Grazing incidence x-ray-diffraction (GXRD)...............................................................54
4.2.3 Texture measurement (pole figure)........................................................................................56
4.2.4 X-ray reflectometry (XRR)...........................................................................................................57
4.3 Rutherford backscattering spectroscopy (RBS)........................................................................57
4.4 Transmission Electron Microscopy (TEM) ..................................................................................59
4.5 Residual stress measurement.....................................................................................................................60
24.5.1 Stress measurement by XRD sin ψ technique ..........................................................60
4.5.2 Ex-situ stress set-up .............................................................................................................................61
4.5.3 In-situ stress set-up...............................................................................................................................64
4.6 Spectroscopic ellipsometry..........................................................................................................................67
4.7 Electrical measurements using four point Probe......................................................................70

5 Growth and in-situ stress evolution of zirconium nitride (ZrN ) films ...............72 x
5.1 Introduction................................72
5.2 Results ...........................................................................................................................................................................73
5.2.1 Correlation between stress with structural, optical and electrical
properties of ZrN films grown at constant pressure (1.0 Pa).........................73 x
5.2.1.1 Deposition characteristics, density and film roughness.....................73
5.2.1.2 Film composition.................................................................................................................74
iv
5.2.1.3 Film structure ..........................................................................................................................76
5.2.1.4 Film texture and cell size of ZrN thin films ...............................................81 x
5.2.1.5 In-situ stress evolution (variation of N flow)............................................83 2
25.2.1.6 X-ray stress measurement (sin ψ technique) .............................................83
5.2.1.7 Optical and electrical properties of ZrN deposited at constant x
pressure (1.0 Pa) ...................................................................................................................87
5.2.2 Effect of sputtering pressure on in-situ stress and structure of ZrN
thin films ......................................................................................................................................................90
5.2.3 Effect of sputtering power on stress development of ZrN films...................93
5.2.4 Discussion.....................95
5.2.4.1 Structure, film density and in-situ stress
(at constant pressure of 1.0 Pa)..............................................................................95
5.2.4.2 In-situ stresses at a various sputtering pressure, relaxation............97
5.2.4.3 In-situ stressputtering power..............................................98
5.2.5 Conclusion ...................................................................................................................................................98

6 Growth and in-situ stress evolution of niobium nitride (NbN ) films ...............100 x
6.1 Introduction.............................100
6.2 Results..........................................101
6.2.1 Correlation between stress with structural, optical and electrical ............101
properties NbN films grown at constant pressure (1.0 Pa)...........................101 x
6.2.1.1 Deposition characteristics and film density...............................................101
6.2.1.2 Film structure .......................................................................................................................101
6.2.1.3 Film Texture..........................................................................................................................105
6.2.1.4 In-situ stress evolution (variation of N flo