If you are my age you will remember the rubber stamp kit you had as a kid. Today’s imprint? Same thing, just really tiny. Apparently the only way to satisfy our ever increasing desire for smaller, faster, lighter devices in our homes and to carry around or attach to our bodies is to stamp features that are smaller than the diffraction limit of light. That’s pretty small.
Everybody talks so glibly about nanotechnology. What is nano? If you are my age you remember when microwave ovens first entered our kitchens. They were supposed to be really short wavelengths. Actually, they are on the short side of radio waves with a wavelength of about 0.1mm. That’s 100,000 nm. That’s not nano.
Shorter than microwaves is the large infrared band of wavelengths. These wavelengths vibrate sympathetically with molecular rotations and metal plasma oscillations (like what goes on on the surface of the sun). Seems pretty small.
Shorter than this and you get into the visible range of light. It never ceases to amaze me that we humans have sensors capable of detecting this particular wavelength of energy. In terms of wavelength, visible light is 400 – 750 nm. So the wavelengths we can see are hundreds of nanos.
The manufacturing method most employed to date for integrated electronic circuits (photolithography) uses 193nm light. Using optical diffraction, this 193nm light allows the creation of features with minimum sizes of 50nm. As we try to go smaller we approach the diffraction limits of the light itself. Hmm.
Well, we can’t stop getting smaller, so in recent years we have cast about for a new method of manufacturing. Enter nanopatterning technology - a process by which you replicate the same pattern over and over with a single template.
It’s a stamp.
