Summary for atomically smooth surfaces on aluminum Discussion
atomically smooth surfaces on aluminum are not directly solved in the thread, but Marc Banks suggests a practical amateur route: study home telescope-mirror grinding and polishing methods. He notes that hobbyists routinely reduce irregularities and deformations to under 10 microns, sometimes less, and that many of those techniques can transfer to materials like quartz and aluminum. The original question asks about making an aluminum substrate smooth enough for DIY microlithography, considering regular polishing followed by electropolishing, and asks what to read to learn more. No one in the thread offers a detailed aluminum-specific chemical-mechanical polishing recipe or confirms that electropolishing alone will achieve the needed surface quality. The main takeaway is to borrow from optical polishing practice rather than expect a simple amateur aluminum process to deliver wafer-like perfection.
January 16, 2014
Q. Some background:
I have been experimenting with D-I-Y microlithography (well, preparing to anyway). In order to do this, I need some sort of substrate. Silicon wafers are both too expensive and too fragile for my purposes. My thoughts are to use aluminum since it is (relatively) cheap. The problem is, however, the fact that the surface needs to be as smooth as possible. How would I go about doing this in a manner that is doable for an amateur such as myself? Chemical-mechanical polishing seems to be what is used for silicon wafers industrially, but this seems beyond the scope of something I could do, and besides I have been unable to find references for how to do it with Aluminum anyway. What about using regular means of polishing, and then electopolishing? What should I read to educate myself on the subject?
Thanks
-Kevin
Kevin Keith
home experimentalist – St. George, Utah, USA
A. Kevin,
While I don’t know that it will provide you with the ‘perfect’ surface, I’d look into how home hobbyists grind telescope mirrors. They are regularly able to get irregularities and deformations down to under 10um (even less in some circumstances).
Many of their polishing techniques should be easily transferable, and you can do it to things like quartz and aluminum.
Hope I’ve helped a bit.
Marc Banks
Blacksmith – Lenoir, North Carolina USA