Atomic force microscopy

• Subject Area: Condensed Matter Physics
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 467555526

The atomic force microscopy (AFM) is one of the important structural analysis methods for the research and optimization of novel functional materials in the field of modern Material Sciences. In particular the quantitative understanding of the correlation of the deposition conditions, the structural characteristics and the functional properties of these materials is of key importance. The AFM-system, which is applied for, will be used in the running as well as planned research projects of the respective working groups for the analysis of complex, multinary and sometimes metastable semiconductor systems. These materials and their corresponding heterostructures will be grown epitaxially by metal organic vapour phase epitaxy (MOVPE) techniques on various crystalline substrates. The AFM will be combined with the complementary high-resolution X-ray diffraction (HR-XRD) and transmission electron microscopy (TEM) techniques. In particular the AFM methodology will be applied to clarify the surface morphology as well as the interface characteristics of novel heterostructures of these materials on lateral length scales ranging from about 10 nm up to 100 µm. The surface and interface step configuration, the formation of terraces, characteristic roughening processes, phase transitions of epitaxial growth surfaces are of key importance for an iterative optimization of novel layer systems. Based on this quantitative understanding of the correlation of epitaxial deposition conditions and structural characteristics only, one can realize novel opto-electronic device concepts for these different material classes ( multinary, metastable III/V-semiconductor materials, IV-based layer structures, novel transition-metal-di-chalcogenides (TMDC) and other 2-dimensional layer systems and their corresponding heterostructures ) for optimized laser applications or for the integration of these functional materials on silicon (Si) substrates. The applied AFM-system will substitute an existing 25-year-old AFM-equipment, which has been used permanently in this period of time, for the structural analysis of surfaces and interfaces of various different semiconductor materials and heterostructures and will extend specifically the AFM-methodology for the wide range of planned research projects including complex selective epitaxial growth also on large area Si-substrates.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Rasterkraftmikroskop
• Instrumentation Group: 5091 Rasterkraft-Mikroskope
• Applicant Institution: Philipps-Universität Marburg
• Leader: Professor Dr. Wolfgang Stolz