Yes, nice to read indeed, action_or_reaction! I do like the pictures! ;-)
At the AGM lab tour we learned that the molecular epitaxy beam (MBE) system does not put only a single layer on the gallium arsenide wafer, but 87 of them consisting of different materials.
Now if only someone whould create a follow-up paper explaining and highlighing the role and importance of TCAD and especially the TDK! It is a (IMHO still underestimated) key enabler for chip developers and fabs.