Role of Low-Energy Electrons (<35 eV) in the Degradation of Fe(CO)5 for Focused Electron Beam Induced Deposition Applications: Study by Electron Stimulated Desorption of Negative and Positive Ions

AbstractWe present the results of electron beam assisted molecular beam epitaxy (EB-MBE) on the growth mode of silicon on CaF2/Si(111). By irradiating the CaF2 surface with low energy electrons, the fluorine is desorbed, leaving an ordered array of F-centers behind. Using atomic force microscopy (AFM), we do not detect any surface damage on the CaF2 layer due to the low energy electron irradiation. The surface free energy of the CaF2 is raised due to the F-center array and the subsequent silicon layer is smoother. Using AFM and X-ray photoelectron spectroscopy (XPS), we find an optimal range of exposures for high temperature (650°C) growth of the silicon overlayer that minimizes surface roughness of the silicon overlayer and we present a simple model based on geometrical thermodynamics to explain this.We observed a similar optimal range of exposures that minimizes the surface roughness for medium (575°C) and low (500°C) growth temperatures of the silicon layer. We present an explanation for this growth mode based on kinetics.

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Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.240 ◽

2017 ◽

Vol 8 ◽

pp. 2410-2424 ◽

Cited By ~ 13

Author(s):

Julie A Spencer ◽

Michael Barclay ◽

Miranda J Gallagher ◽

Robert Winkler ◽

Ilyas Unlu ◽

...

Keyword(s):

Electron Beam ◽

Structural Integrity ◽

High Surface ◽

High Surface Area ◽

Chloride Ions ◽

Residual Chlorine ◽

Scanning Electron Microscopy Data ◽

Electron Beam Induced Deposition ◽

Electron Stimulated Desorption ◽

Microscopy Data

The ability of electrons and atomic hydrogen (AH) to remove residual chlorine from PtCl2 deposits created from cis-Pt(CO)2Cl2 by focused electron beam induced deposition (FEBID) is evaluated. Auger electron spectroscopy (AES) and energy-dispersive X-ray spectroscopy (EDS) measurements as well as thermodynamics calculations support the idea that electrons can remove chlorine from PtCl2 structures via an electron-stimulated desorption (ESD) process. It was found that the effectiveness of electrons to purify deposits greater than a few nanometers in height is compromised by the limited escape depth of the chloride ions generated in the purification step. In contrast, chlorine atoms can be efficiently and completely removed from PtCl2 deposits using AH, regardless of the thickness of the deposit. Although AH was found to be extremely effective at chemically purifying PtCl2 deposits, its viability as a FEBID purification strategy is compromised by the mobility of transient Pt–H species formed during the purification process. Scanning electron microscopy data show that this results in the formation of porous structures and can even cause the deposit to lose structural integrity. However, this phenomenon suggests that the use of AH may be a useful strategy to create high surface area Pt catalysts and may reverse the effects of sintering. In marked contrast to the effect observed with AH, densification of the structure was observed during the postdeposition purification of PtC x deposits created from MeCpPtMe3 using atomic oxygen (AO), although the limited penetration depth of AO restricts its effectiveness as a purification strategy to relatively small nanostructures.

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Gas phase low energy electron induced decomposition of the focused electron beam induced deposition (FEBID) precursor trimethyl (methylcyclopentadienyl) platinum(iv) (MeCpPtMe3)

Physical Chemistry Chemical Physics ◽

10.1039/c2cp42637d ◽

2012 ◽

Vol 14 (42) ◽

pp. 14611 ◽

Cited By ~ 46

Author(s):

Sarah Engmann ◽

Michal Stano ◽

Štefan Matejčík ◽

Oddur Ingólfsson

Keyword(s):

Electron Beam ◽

Gas Phase ◽

Low Energy ◽

Energy Electron ◽

Low Energy Electron ◽

Electron Beam Induced Deposition ◽

Induced Decomposition

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The role of electron-stimulated desorption in focused electron beam induced deposition

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.4.56 ◽

2013 ◽

Vol 4 ◽

pp. 474-480 ◽

Cited By ~ 16

Author(s):

Willem F van Dorp ◽

Thomas W Hansen ◽

Jakob B Wagner ◽

Jeff T M De Hosson

Keyword(s):

Activation Energy ◽

Growth Rate ◽

Electron Beam ◽

Electron Irradiation ◽

Carbon Membrane ◽

Average Value ◽

Fundamental Process ◽

Electron Stimulated Desorption ◽

Substrate Temperatures

We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growth rate is lower at higher substrate temperatures. From Arrhenius plots we calculated the activation energy for desorption, E des, of W(CO)6. We found an average value for E des of 20.3 kJ or 0.21 eV, which is 2.5–3.0 times lower than literature values. This difference between estimates for E des from FEBIP experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption.

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Lithography with low-energy electrons

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100112324 ◽

1984 ◽

Vol 42 ◽

pp. 468-471

Author(s):

T. H. Newman ◽

R. F. W. Pease ◽

K. J. Polasko ◽

Y. W. Yau

Keyword(s):

Electron Beam ◽

High Resolution ◽

Electron Beam Lithography ◽

Proximity Effects ◽

Low Energy ◽

Low Energy Electrons ◽

Circuit Fabrication ◽

Electron Range ◽

Exposure Process

Two prominent problems of electron beam lithography are slow throughput and proximity effects. The former arises from the serial nature of the exposure process; the current available in a beam of given resolution is limited by electron optical considerations and the resist sensitivity is limited by material considerations such that a dose of 1 μC/cm2 at 20 kV is required for the most sensitive resist and ten times that dose if high resolution is required.Proximity effects are caused by electrons scattered through lateral distances greater than the resolution of the pattern; a 20 keV electron in silicon has a range of about 3 μm whereas feature sizes are often less than 1 μm. Lowering the energy of the exposing electrons to, say, 2 keV would lower the electron range to less than 0.1 μm in silicon and thus effectively eliminate proximity effects as far as semiconductor circuit fabrication is concerned.

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