Tannersfriend: SOITEC just has a little problem now: they recently sold their GaAs epitaxi IP ; as I said: big mistake!
Oh, that's funny! Soitec still has its resp. now IntelliEPI's Speciality Electronics subsidiary on their on their homepage although they sold it – hm.
http://www.soitec.com/en/products-and-services/specialty-electronics/