Wednesday, 22 April 2009
So in this picture we see a strange parallel wall structure which somehow survived the etching. Most likely it was a scratch on the surface which caused the Gallium Nitride (the semiconductor in question) to stand up to the malevolent potassium and hydroxide ions. The point is that:
a) It looks pretty
b) The GaN itself seems to be made from two distinct layers (we're guessing it is to do with some "dopants" getting involved when the wafer was grown)
c) It's a minor success but it's the first success that I've had in eighteen months of PhD
d) That broken wasteland at the bottom of the double wall is sapphire. As in the gemstone.
e) The image was taken with a FIB (essentially you nail Gallium ions at the surface and look for the electrons which come flying off)