Vacancy No. IPS 02-2022

IPS 02-2022 Master Thesis: Growth and characterization of Indium and Gallium droplets on Si(111) surfaces

Job description

One major field of research for the forthcoming generations of nanoelectronic and nanophotonic devices is the integration of III-V semiconductors with the silicon-based CMOS technology. A very promising approach is the growth of III-V nanowires (NWs) on silicon substrates. While the fabrication of NWs of several materials on Si(111) is well established, the growth of InAs NWs remains a challenge due to the narrow window of suitable parameters. On the other hand, InAs exhibits among the highest values of electron mobility in semiconductors and therefore the integration of InAs NWs on Si is highly desirable.

It was shown for GaAs NWs that a specific surface manipulation procedure prior to the actual nanowire growth can significantly improve the sample quality in several aspects. During this process Ga droplets are deposited on the SiO2 oxide layer covering the Si(111) surface in order to etch nanoholes into the oxide to form nucleation sites. In a second step, again Ga precursor droplets are deposited to fill the nanoholes and to form nucleation seeds for the subsequent growth of GaAs nanowires. The quality of the nanowires is determined by the properties of these precursor droplets, such as wetting angle, size, filling ratio of the nanoholes, etc. Aim of this thesis is to transfer the knowledge from the case of GaAs to the growth of high-quality InAs nanowires. Main objective will be the morphological characterization of the etched nanoholes and the In droplets by in situ atomic force microscopy (AFM). The UHV-Cluster at IPS offers the unique possibility to conduct both, growth and characterization by AFM, under ultra-high-vacuum conditions, avoiding the deterioration of the specimen by oxidation or other contaminations. In the course of this work, you will acquire knowledge and hands-on experience in ultrahigh vacuum technology, growth of nanostructures by molecular beam epitaxy and various surface characterization methods.

Personal qualification
  • You study physics or material science and have basic knowledge in solid state physics.
  • You are willing to familiarize yourself with new topics and methods
  • You are interested in lab work and hands-on experiments
  • You’re fluent in English
Organizational unit

Institute for Photon Science and Synchrotron Radiation (IPS)

Starting date

after consultation

Contact person
Contract Duration

According to study regulations

Application up to

 July 04, 2022

Contact person in line-management

For further information, please contact Dr. Jochen Kalt, e-mail:


Please apply by clicking on "Apply" below.

Recognized severely disabled persons will be preferred if they are equally qualified.