Banner

Home | Staff | Research | Publications | Seminars/Workshops | Teaching | Open Positions | How to find us | Intranet

Deutsch | English

Electron-initiated chemistry for nanotechnology


Electron-induced chemistry is a versatile approach to the fabrication of nanoscale materials and devices. Depending on the electron source used in such processes, different types of nanostructures are accessible. Using a tightly focused beam, structures of arbitrary shape with dimensions in the nanometer regime can be directly written on surfaces. This so-called focused electron beam induced deposition (FEBID) produces solid materials through electron-induced decomposition of volatile precursors such as metal organic compounds.

In contrast, divergent lower-energy electron beams process surfaces on macroscopic length scales. In this case, patterns can be imprinted onto a surface by electron exposure through a mask. Such patterns themselves often consist of smaller structures, namely, when electron exposure leads to formation of nanoparticles in the irradiated surface area. Hierarchical surface patterns are thus accessible.

Our research aims at a detailed understanding of chemistry underlying the fabrication of nanoscale materials by processes utilizing electron beams. Such processes are commercially relevant in areas such as the repair of masks for photolithography. Our activities are part of an international network developed through the previous European COST Action CELINA (Chemistry for ELectron-Induced NAnofabrication) coordinated by us and extended within the Marie-Curie Innovative Training Network ELENA (Low energy ELEctron driven chemistry for the advantage of emerging NAnofabrication methods) . A few results are highlighted here.


Electron-induced fabrication processes often do not yield a pure material. Instead, significant amounts of unwanted contaminations are embedded in the deposits. For instance, halide ligands are difficult to remove and thus require extensive irradiation. However, desorption of Cl ligands is enhanced in presence of NH3 because HCl is formed. Therefore, cisplatin decomposes under electron irradiation to yield pure platinum making it an attractive alternative to established FEBID precursors for platinum deposition.

ESD


Water vapour in combination with electron irradiation is an efficient means to remove carbon from nanoscale materials. In such a process, water produces reactive species that can break down carbon residues and remove it primarily in form of carbon monoxide. We apply different types of desorption experiments in ultrahigh vacuum to unravel the fundamentals of this chemistry.

Experimente

Electron-irradiation transforms surface grown metal-organic layers into a variety of nanostructured materials. For instance, copper(II) oxalate is converted to pure copper nanoparticles while the counterions are quantitatively removed as CO2. In contrast, surface layers of HKUST-1 yield copper nanoparticles embedded in an organic matrix, a material which can serve as template for autocatalytic decomposition of Fe(CO)5. Comparing HKUST-1 to copper(II) oxalate, we have started to unravel the fundamental chemistry of such surface activation by electron irradiation.

Nanopartikel

More information:

(1) Focused electron beam-induced processing;
D.H. Fairbrother, S.G. Rosenberg, C.W. Hagen, I. Utke, P. Swiderek,
in Low-Energy Electrons: Fundamentals and Applications, O. Ingólfsson (Ed.), Pan Stanford (2019), pp. 219.

(2) Cisplatin as Potential Pt FEBID Precursor: NH3 Ligands Enhance the Electron-Induced Removal of Chlorine;
M. Rohdenburg, P. Martinovic, K. Ahlenhoff, S. Koch, D. Emmrich, A. Gölzhäuser, P. Swiderek
J. Phys. Chem. C 123, 21774-21787 (2019).

(3) Electron-induced chemistry of surface-grown coordination polymers with different linker anions;
K. Ahlenhoff, S. Koch, D. Emmrich, R. Dalpke, A. Gölzhäuser, P. Swiderek
Phys. Chem. Chem. Phys. 21, 2351-2364 (2019).

(4) Electron beam induced surface activation of the metal organic framework HKUST 1: Unravelling the underlying chemistry;
K. Ahlenhoff, C. Preischl, P. Swiderek, H. Marbach,
J. Phys. Chem. C 46, 26658-26670 (2018).

(5) Chemistry for electron-induced nanofabrication;
P. Swiderek, H. Marbach, C.W. Hagen,
Beilstein J. Nanotechnol. 9, 1317-1320 (2018).

(6) Electron-driven and thermal chemistry during water-assisted purification of platinum nanomaterials generated by electron beam induced deposition;
Z. Warneke, M. Rohdenburg, J. Warneke, J. Kopyra, P. Swiderek,
Beilstein J. Nanotechnol. 9, 77-90 (2018).

(7) Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II) oxalate precursor layers;
K. Rückriem, S. Grotheer, H. Vieker, P. Penner, A. Beyer, A. Gölzhäuser,
P. Swiderek, Beilstein J. Nanotechnol. 7, 852-861 (2016).

(8) The role of NH3 in the electron-induced reactions of adsorbed and solid cisplatin;
J. Warneke, M. Rohdenburg, Y. Zhang, J. Orzagh, A. Vaz, I. Utke, J.Th.M. De Hosson, W.F. van Dorp, P. Swiderek; J.Phys.Chem. C 120, 4112-4120 (2016).

(9) Acetone and the precursor ligand acetylacetone: Distinctly different electron beam induced decomposition?
J. Warneke, W. F. Van Dorp, P. Rudolf, M. Stano, P. Papp, S. Matejcik, T. Borrmann, P. Swiderek;
Phys.Chem.Chem.Phys. 17, 1204-1216 (2015).

(10) Fundamentals of interactions of electrons with molecules;
John H. Moore, Petra Swiderek, Stefan Matejcik and Michael Allan,
in Nanofabrication using focused ion and electron beams: Principles and applications, P. Russell, I. Utke and S. Moshkalev (Eds.), Oxford University Press, New York (2012), pp. 184.

(11) Low Energy Electron Induced Decomposition and Reactions of Adsorbed Tetrakis(trifluorophosphine)platinum (Pt(PF3)4); K.Landheer, S.G.Rosenberg, L.Bernau, P.Swiderek, I.Utke, K.Hagen, D.H.Fairbrother, J. Phys. Chem. C 115, 17452 (2011).

(12) Electron-induced reactions of MeCpPtMe3 investigated by HREELS;
M.N.Hedhili, J.H.Bredehöft, P.Swiderek; J. Phys. Chem. C 113, 13282 (2009).


ELENA-Bild


Marie Sklodowska-Curie Innovative Training Network ELENA
( Low energy ELEctron driven chemistry for the advantage of emerging NAnofabrication
methods)

CELINA-Bild


COST Action CM1301 CELINA
( Chemistry for ELectron Induced NAnofabrication)

LogoUniversity of Bremen | Institute for Applied and Physical Chemistry | Tel. +49-421-218-63171 | Login | Imprint