Is there an optical technique that can small features to an accuracy of ~100nm

Question

The dimension to be measured is the width (nanometer accuracy on height is 'relatively' easy). The features to be measured are 2 - 10 micron wide. X-ray and deep UV wavelengths cannot be used.

Answer 1

100 nm is just below the best resolution you can get with visible light:

http://en.wikipedia.org/wiki/Angular_res...

The calculation above gives 187 nm using blue light and the widest possible lens in oil.  I guess if you go into the near UV, you could do a little better.  You'll need to get the wavelength down to the 250-300nm range (middle of UV spectrum) to achieve that resolution.

Answer 2

Confocal light microscopes can image detail with 100nm resolution using blue wavelengths or shorter.  However, these devices are expensive.  Your best bet is to rent time on one, either from the manufacturer or a university.

Wikipedia is not a reliable knowledge source.