Wednesday, October 2, 2013

A short update on cleaning and imaging procedures...

Let me be (probably not the first) one to say that if research didn't slog forward it probably wouldn't move at all.  I have been working with AFM in attempts to find the right combination of AFM probe and cleaning procedure (of both the substrate and the liquid cell) which will yield micelles on the surface.  I have been corresponding with contacts on campus which have experience with cleaning AFM probes (which I have mentioned before can become contaminated by the gel packing which the are stored and shipped in) but once again the difficulty of meshing schedules makes that endeavor a slow one.  I am meeting with another research specialist today in hopes of looking at the set up they use and replicating their procedure and apparatus somewhere in our building so that I, and other who are trained to use the AFM, will have access to it so that cleaning of AFM probes will not be such a hassle.  I was able to come up with a contamination free way of transporting probes across the university campus which will keep the probes safe, secure and clean following the cleaning, but if I am never able to get assistance in the cleaning then the container is not worth much (although I'm happy that the simple design we came up with works so well).  
On another AFM front I am also spending time trying to locate the 30 nm and smaller lines which is proving to be much more difficult than the 50 nm lines I have posted about before on here. Those lines, which were much more in number creating an array that later proved to be too big for the field size and may have contributed to the lines large widths, were also slightly sloped on the side walls which caused the trench bottom to be smaller than the top (as previously discussed) and made them much easier to find.  The new set of e-beam etches were not as sloped and were smaller (which is good!) are much harder to find even with smaller radii AFM tips.  So far I have worked with tips down to 1 nm but from literature I have found that without cleaning of the probes the contamination of the tips might be the reason that the lines are so difficult to find (The Journal of Physical Chemistry B, 1998. 102(22): p. 4288-4294. and The Journal of Physical Chemistry C, 2008. 112(38): p. 14902-14906. and The Journal of Physical Chemistry B, 1999. 103(40): p. 8558-8567. to name a few).  So once the cleaning procedure has been worked out I can tell if the lines and micelles are hard to image because of the contamination or because my procedure is still lacking.  Either way I will update regarding these matters soon!