Mutus et al. at the University of Alberta have recently examined a suspended graphene film by low energy electron point projection microscopy (LEEPPM). [arXiv:1102.1758] Even though the electron energy was only 100-200 eV, approximately 75% of the electrons get through the film. With an effective source size of < 5Å, imaging resolution is quite good. The authors claim that the low beam energy does not result in sample contamination in the way higher voltage techniques such as STEM do. (I find this claim puzzling, since it is the secondary electrons which are largely responsible for chemical reactions induced by high voltage e-beams.) They speculate that a graphene film could be used as the ultimate microscope slide for imaging thin objects by PPM.

In EUV lithography, carbon deposition on the optics seriously degrades performance. A nice experiment at the University of Hyogo has shown that bleeding oxygen or ozone into the optics while irradiating with EUV can remove the deposits. [J. Vac. Sci. Technol. B 29, 011030 (2011); doi:10.1116/1.3533945]
An old invention by Somekh comes to mind; he discovered the same trick for electron beam systems in 1999. [US 6394109]

The Lyding group at the University of Illinois at Urbana—Champaign reports the writing of < 5 nm metallic structures by EBL. The lithography was carried out by electron beam induced deposition of hafnium diboride in a UHV scanning tunneling microscope.

Find the publication at DOI: 10.1021/nn1018522 .

In electron beam lithography, we usually attempt to squeeze as much current into the beam as possible. What about the other extreme? Can we arrange to get one electron at a time in the beam, and what use might that have?

The Baum group at the Max Planck Institute of Quantum Optics has done just this. Reporting in PNAS [doi: 10.1073/pnas.1010165107], they demonstrate single-electron pulses generated by photoemission. The photoemission in turn is driven by tuned, femtosecond UV pulses. Tuning of the UV wavelength turns out to be important for the bandwidth, coherence and duration of the resulting electron pulse. The experiment results in a transverse (electron) coherence of 2.5 nm, quite adequate for diffraction studies.

Now, with a coherence length of 2.5 nm and a duration of 100 fs or less, one can study atomic-scale dynamics in condensed matter and molecules by so-called four-dimensional imaging. Many interesting phenomena become visible; see the first twelve or so references in the paper.