Optimization of STM-tip preparation methods
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
The Scanning Tunneling Microscope (STM) was invented by Gerd Binnig and Heinrich Rohrer and gave them the Nobel Prize in Physics 1986. STM can give us atomic resolution of a surface by applying a voltage between a very sharp tip (STM-tip) and the surface of a material that we want to examine. The STM-tip is moving over the surface and a computer is collecting the tunnel current in every single point to create a digital image.
This diploma work is focused on the preparation of the STM-tip. The preparation method that is used is electrochemical etching of a tungsten wire. The sharper the STM-tip is the better resolution in the STM images we can get. With the purpose to get as sharp tip as possible and with a well-defined geometry, we prepared several tips by systematically varying the etching parameters such as voltage, current, concentration and wire length. A new method has been tested to minimize the oxidation on the surface and finally the tips were characterized with scanning electron microscope (SEM).
Place, publisher, year, edition, pages
2011. , 28 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-30873OAI: oai:DiVA.org:kth-30873DiVA: diva2:402068
Master of Science in Engineering - Microelectronics
Götelid, Mats, Associate Professor