1 Introduction ................................................. 1
2 Basics ....................................................... 3
2.1 Clusters and their properties ........................... 3
2.2 Patterning methods ...................................... 4
2.3 Graphene ................................................ 5
2.4 Graphite oxidation ...................................... 8
3 Experimental methods and setup ............................... 9
3.1 Focused Ion Beams ....................................... 9
3.1.1 Liquid Metal Ion Source .......................... 9
3.1.2 The ionLiNE tool ................................ 10
3.1.3 Ion dose definitions ............................ 13
3.1.4 Origin of the defect distribution or structure
width ........................................... 15
3.2 Scanning Tunneling Microscopy .......................... 16
3.2.1 Principles ...................................... 16
3.2.2 LT-System ....................................... 17
3.2.3 RT-System ....................................... 18
3.2.4 Data analyzing .................................. 19
3.3 Scanning Tunneling Spectroscopy ........................ 21
3.4 Photo Emission Electron Microscopy ..................... 22
4 Sample preparation .......................................... 23
4.1 Substrate properties ................................... 23
4.2 Nano-pit fabrication ................................... 24
4.3 Cluster fabrication .................................... 27
5 Results and Discussion ...................................... 29
5.1 Ion dose dependence .................................... 29
5.2 Patterning with low ion dose ........................... 31
5.2.1 Nano-pits ....................................... 31
5.2.1.1 Nano-pit patterns ...................... 31
5.2.1.2 Distance dependence .................... 33
5.2.1.3 Influence of the pit size .............. 35
5.2.1.4 Beam characterization using
nano-pits .............................. 35
5.2.1.5 Finding patterns ....................... 39
5.2.2 Cluster growth .................................. 41
5.2.2.1 Silver cluster patterns ................ 42
5.2.2.2 Lead layer patterns .................... 47
5.2.2.3 Lead cluster patterns .................. 50
5.3 Patterning with high ion dose .......................... 59
5.3.1 Nano-cavities ................................... 59
5.3.1.1 Nano-cavity patterns ................... 59
5.3.1.2 Penetration depth of gallium ions ...... 61
5.3.1.3 Beam characterization using nano-
cavities ............................... 62
5.3.1.4 Graphene nano-structures ............... 63
5.3.2 Island growth ................................... 67
5.4 Cluster properties .................................... 70
5.4.1 Gold clusters ................................... 70
5.4.2 Silver clusters ................................. 70
5.4.2.1 Cluster height ......................... 71
5.4.2.2 Cluster facet .......................... 72
5.4.2.3 Cluster stability ...................... 74
5.4.3 Lead clusters ................................... 74
5.4.3.1 Cluster height ......................... 75
5.4.3.2 Cluster facet .......................... 81
5.4.3.3 STS measurements ....................... 84
5.4.3.4 Cluster stability ...................... 85
5.4.4 Discussion ...................................... 88
6 Monte Carlo Simulations ..................................... 91
6.1 Ion impact ............................................. 91
6.1.1 About TRIM ...................................... 92
6.1.2 Simulation results .............................. 92
6.2 Oxidation .............................................. 98
6.2.1 Algorithm ....................................... 98
6.2.2 Characterization ................................ 99
6.2.3 The physical background ........................ 106
6.2.4 Simulation results ............................. 108
6.2.4.1 Oxidation process ..................... 108
6.2.4.2 Random defects ........................ 110
6.2.4.3 Defect groups ......................... 111
7 Summary .................................................... 115
8 Outlook .................................................... 117
9 References ................................................. 119
10 Glossary ................................................... 135
11 Acknowledgements ........................................... 139
| 
