I am still not able to use the e-beam equipment at the University of Tulsa due to the program not having x-y control over the beams position. The program is able to communicate with the hardware and activate the beam but because the beam does not move anywhere during the process all that is left is a burned spot where all of the beam energy is focused during the trial. The beam technician has been working with me on this project, trying to get the x-y control back but still has had no luck and has contacted the e-beam company for support. We are awaiting their response and hope that this will allow us to continue with the project.
One thing that I am unsure about lately is the surface integrity once the etching has been done. Long story short, the PMMA bonding on the silica is disrupted by the e-beam, so that when the sample is immersed in a developer, the disrupted bits lift away leaving the pattern that we are looking for. I am not worried about the resolution because that has already been shown to have high definition. I am concerned because the developer is an alcohol and ketone, which I am hopeful will not leave a residue. If it does, I am not sure how it will affect the adsorption of the surfactants when we move onto that stage of the research. I am thinking I will run a few tests with the developer on a clean silicon sample and determine how much of a film, if any, the developer leaves behind after evaporation.
The other side of the project, involving etching the silicon, is also having difficulty, as the etching machine is having a performance check and will be available again shortly. Until then, I am going to focus on the developer residue tests and nanosphere soaking, for retaining spheres and monolayer converage.
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