Morning Star, - I have no doubt that it can be done.

I just know the story when the SI producers (e.g. Wacker Siltronic) went from 150 to 200, then to 300mm). These were huge projects. It is not like just triggering a switch from 150 to 200. A lot of expensive hardware is involved to build and optimize zone melting furnaces, saws, polishing machines... I hope they can use a lot of the existing Si-technology for GaAS!