Organic monolayers on semiconductor surfaces [Elektronische Ressource] : from electron-beam induced modification to wettability control / vorgelegt von Eugeniu Balaur

Ebalaur

Informations

• Publié par: friedrich-alexander-universitat_erlangen-nurnberg
• Publié le: 01 janvier 2007
• Nombre de lectures: 4
• Langue: English
• Poids de l'ouvrage: 18 Mo

Extrait

Organic monolayers on semiconductor
surfaces: from electron-beam induced
modification to wettability control


Der Technischen Fakultät der
Universität Erlangen-Nürnberg
zur Erlangung des Grades



DOKTOR-INGENIEUR


vorgelegt von

Eugeniu Balaur


Erlangen 2006

















Als Dissertation genehmigt von
der Technischen Fakultät der
Universität Erlangen-Nürnberg



Tag der Einreichung: 04.10.2006
Tag der Promotion: 23.02.2007
Dekan: Prof. Dr. A. Leipertz
Berichterstatter: Prof. Dr. P. Schmuki
Prof. Dr. R. Fink
Organische Monolagen auf
Halbleiteroberflächen: Von
Elektronenstrahl-induzierter
Modifikaktion zu kontrollierter
Benetzbarkeit

Der Technischen Fakultät der
Universität Erlangen-Nürnberg
zur Erlangung des Grades


DOKTOR-INGENIEUR

vorgelegt von

Eugeniu Balaur

Erlangen 2006

















Als Dissertation genehmigt von
der Technischen Fakultät der
Universität Erlangen-Nürnberg



Tag der Einreichung: 04.10.2006
Tag der Promotion: 23.02.2007
Dekan: Prof. Dr. A. Leipertz
Berichterstatter: Prof. Dr. P. Schmuki
Prof. Dr. R. Fink
Acknowledgements
The intellect cannot criticize itself, simply because it cannot be compared with
other species of intellect and because its capacity to know would be revealed only in
the presence of "true reality," i.e., because in order to criticize the intellect we should
have to be a higher being with "absolute knowledge." Knowledge works as a tool of
power and drive for knowledge makes the intellect to come along with another one in
order to compare things for finding out the “true reality”, triggering, essentially, the
humanity progress.
In this context, I would like to express my gratitude to the people who
contributed to my intellectual improvement and sustained me during all these years of
my PhD.
Above all, I would like to show my appreciation to my supervisor Patrik
Schmuki. During these years I have known Patrik as a person with an overly
enthusiasm regarding research, whose task was to present high-quality work in a team
environment.
I would also like to express my admiration to my professor from Moldova Ion
Tighineanu who first guided me on the path of science and whose young enthusiasm
strikes me always.
I owe lots of gratitude to my friend and colleague Thierry Djenizian for
showing me the way of research at my first steps toward science. He could not even
realize how much I have learned from him. Besides of being an excellent colleague,
Thierry was as close as a relative and a good friend to me. I am really glad that I have
come to get know him in my life.
The chain of my gratitude will continue with the great appreciation to some
friends and members of LKO: Andrei Ghicov, Yan Zhang, Andres Gabriel Muñoz. I
would also like to thank charming Helga Hildebrand not only for performing all the
surface analysis but also for helping and guiding me in general stuff.
I take the opportunity to thank also my close friend Eugeniu Foca whose
support I felt despite the long distance between us.
I am very grateful to my wife Viorica, for her love and patience during the PhD
period. I feel a deep sense of gratitude for my parents and my brother who formed part
of my vision and taught me the good things that really matter in life.

CONTENTS i
CONTENTS

ABSTRACT…………………………………………………………………..…1


CHAPTER 1
OVERVIEW………………………………………………………………….…4

1.1 Introduction…………………………………………………………….….4

1.2 Ultrathin organic films in nanoscience………………………………...…7
1.2.1 Organically modified surfaces…………………………………………...7
1.2.2 SAMs as constituents of nanotechnology………………………………10

1.3 Patterning techniques for nanolithography………………………...…..11
1.3.1 Particle-beam based lithography………………………………………..11
1.3.2 Lithography based on scanning probe microscopy……………………..14
1.3.3 Other patterning techniques………………………………………….....18

1.4 Scope of this research…………………………………………………….20


CHAPTER 2
THEORETICAL ASPECTS AND MOTIVATION………………………...22

2.1 Preparation of SAMs………………………………………………….....22
2.1.1 Organic thin films, concept of self-assembly…………………………..22
2.1.2 SAMs on Si(111) surfaces……………………………………………...25
2.1.3 SAMs on TiO surfaces…………………………………………….......29 2

2.2 Concept of electron-beam lithography………………………………….32
2.2.1 Principles of the Scanning Electron Microscopy……………………....32
2.2.2 Electron-specimen interactions………………………………….……..34
2.2.3 Electron-beam lithographic techniques………………………………...37

2.3 Mechanically activated surfaces………………………………………...40
2.3.1 Principles of the Atomic Force Microscopy…………………………....40
2.3.2 Scratching as a patterning method……………………………………...43

2.4 Concept of wetting. Hydrophobic and hydrophilic surfaces…………..45
2.4.1 Wetting theory………………………………………………………….45
2.4.2 Water interaction on planar and rough surfaces………………………..47
ii CONTENTS
CHAPTER 3
EXPERIMENTAL…………………………………………………………….50

3.1 SAMs attachment………………………………………………………...50
3.1.1 Organically modified Si(111) surfaces…………………………………50
3.1.2 SAMs on flat and porous TiO surfaces………………………………..52 2

3.2 Electron beam treatment………………………………………………...54
3.2.1 Scanning Electron Microscope…………………………………………54
3.2.2 Elphy Quantum lithographic technique………………………………...55
3.2.3 Exposure parameters…………………………………………………...55

3.3 Scratching of SAM-modified silicon…………………………………….57
3.3.1 AFM based nanoscratching…………………………………………….57
3.3.2 Microscratching…………………………………………………….......58

3.4 Cupper deposition experiments…………………………………………59
3.4.1 Electrodeposition of Cu on Si(111)…………………………………….59
3.4.2 Immersion plating of Cu on Si(111)……………………………………60

3.5 UV light induced modification of TiO surfaces………………………..60 2
3.6 Surface Analysis Techniques…………………………………………….61
3.6.1 X-Ray Photoelectron Spectroscopy (XPS)…………………………......61
3.6.2 Auger Electron Spectroscopy (AES)…………………………………...61
3.6.3 Attenuated Total Reflectance Fourier Spectroscopy (ATR-FTIR)…….62
3.6.4 Contact angle measurements…………………………………………...63
3.6.5 Photoelectrochemical measurements…………………………………...63


CHAPTER 4
ORGANIC THIN FILMS ON SEMICONDUCTOR SURFACES.
RESULTS AND DISCUSSIONS.…………………………………………….64

4.1 Self-assembled monolayers on H-Si(111) surfaces……...64
4.1.1 Attachment of different SAMs: influence of chain length and
functional group……….………………………………………………64
4.1.1.1 XPS studies……………………………………………………...64
4.1.1.2 ATR-FTIR spectroscopy……………………………………......86
4.1.1.3 Contact angle measurements…………………………………....90
4.1.1.4 Electrochemical properties……………………………………...92
4.1.1.5 Conclusion……..………………………………………………101

CONTENTS iii

4.1.2 Electron-beam induced modification of SAMs…………………….102
4.1.2.1 Cupper selective deposition……………………………………102
4.1.2.2 Influence of e-beam dose………………………………………107
4.1.2.3 Influence of SAM on e-beam treatment……………………….114
4.1.2.4 Influence of e-beam accelerating voltage……………………...117
4.1.2.5 Conclusion……………………………………………………..121

4.1.3 Cu deposition on scratched SAMs……………………………….....123
4.1.3.1 Micro- and nanoscratching…………………………………….123
4.1.3.2 Immersion plating……………………………………………...125
4.1.3.3 Electrochemical deposition…………………………………....131
4.1.3.4 Conclusion………………..……………………………………133

4.2 Self-assembled monolayers on TiO surfaces………….136 2
4.2.1 Attachment of different SAMs: influence of head group………….136
4.2.1.1 XPS studies…………………………………………………….136
4.2.1.2 Conclusion……………………………………………………..149

4.2.2 Wettability of flat and porous SAMs modified TiO surfaces…….150 2
4.2.2.1 Influence of the substrate geometry…………………………...150
4.2.2.2 Influence of the surface chemistry…………………………….160
4.2.2.3 UV light-induced changes of wetting behaviour………………163
4.2.2.4 Conclusion…………………………………………………..…171

MAIN CONCLUSIONS……………………………………………………..174
REFERENCES………………………………………………………………178
LIST OF SYMBOLS………………………………………………………...192
LIST OF PUBLICATIONS…………………………………………..……..196
CURRICULUM VITAE…………………………………………………….198