Development of characterisation methods of sub-10 nm structures

Domain topic

Nano Physics



Single-digit (<10 nm) nanofabrication is one of the hottest topics in nanotechnology nowadays as it could provide a molecular self-assembly processing route for integrated circuits with sub 10 nm resolution. However, as the size of nanostructures goes below few nanometers, it is becoming increasingly difficult to characterise them in terms of size uniformity, composition, electronic, optical and other properties. This is particularly true for regular arrays of sub-10 nm nanostructures, produced by "bottom-up" techniques, such as block-copolymers or other self-organising systems. Further processing steps of pattern transfer, for example, dry etching or epitaxial growth, may result in additional deviations in properties of nanostructure arrays, which are difficult to measure. In the current project we would like to develop characterisation techniques based on instrumentation at DESY, to characterise sub-10 nm regular nanostructure arrays, fabricated at Lund University. Such measurement techniques will not only be quality characterisation tools, but will also provide a deeper understanding of separate fabrication steps for the ultra-high resolution pattern transfer, e.g. dry etching, sequential infiltration synthesis, epitaxy and others.

Project Description

In the current project we shall use high-𝜒 block copolymers (BCP), e.g. PS-b-MH, to form regular arrays of sub-10 nm features on a Si surface, with subsequent modification of the BCP layer by infiltration, reactive ion etching or other techniques. Grazing Incidence Small Angle X-ray Scattering (GISAXS) will be used to obtain information on the pattern size, potential shifts in the block copolymer pitch as a function of the guiding pattern of directed self-assembly BCP nanostructures, as well as the overall pattern fidelity over large sample areas with sub-nanometre accuracy as it is covered by the footprint of the X-rays in GISAXS geometry. The reciprocal-space GISAXS data will be complemented by real-space (AFM, SEM) information to gain a comprehensive insight into the transferred pattern features.

Methodological keywords

Single-digit nanofabrication, block-copolymer nano-lithography, directed self-assembly, Grazing Incidence Small Angle X-ray Scattering (GISAXS)