Hi Jaroslaw, Since I use the same process with the same results both on Si/SiOx (just resist) and Saphirre Wafers (7nm Al on top), the influence seems to be very small. For my structures, beam focus and development seem to have a much larger influence on the outcome, but bear in mind that this is for very small structures ( 150 micron writefield, rectangles about 50 microns long and 1 micron wide, connecting "bow ties" with a 50 nm long single pixel line in the middle). If you need more info, just send me an email :-) Best, Gabriel Gabriel Puebla-Hellmann ETH Zuerich Laboratory for Solid State Physics Quantum Device Lab HPF D12 Schafmattstr. 16 8093 Zurich Switzerland Tel: +41 44 633 71 24 www.qudev.ethz.ch -----Original Message----- From: mems-talk-bounces+gabriepu=phys.ethz.ch@memsnet.org [mailto:mems-talk-bounces+gabriepu=phys.ethz.ch@memsnet.org] On Behalf Of Jaroslaw Syzdek Sent: Monday, August 15, 2011 9:31 PM To: mems-talk@memsnet.org Subject: [mems-talk] E-beam evaporate metal onto PMMA Another PMMA question, that is more general in nature - when I e-beam evaporate metal onto my PMMA resist - how much does it affect its sensitivity for e-beam writing? during e-beam evaporation there's a lot of electrons and x-rays in the chamber. I don't know how severe that is and how much it affects the dosage during writing... thanks in advance for any info on that. Jaroslaw Syzdek