...Extract from an old report from 2010 out of "Association of German Engineers"
SEMICONDUCTOR
Gallium Arsenide under pressure
(don't take the headline serious its from 2010 and with google translation)
extract from report
The fact that the arsenic used is extremely toxic in pure form and in many compounds, naturally leads to the fact that in the production of GaAs extreme care should be exercised.And not only there: also in the disposal of waste products.
This the lack in comparison with Si mass application market are perhaps the reasons why there are only four worldwide manufacturers that have adopted the material: two in Japan, one each in China and Germany: the Freiberger Compound Materials (FCM) in Saxony, the about one-third of the world market served.
Original Link to Product description of German FCM Company:
http://www.freiberger.com/fileadmin/Download/GaAs_kompakt_Produktinfo_dt_Rev_I.pdf
Translation of Product description FMC = Freiberger Compund Materials:
http://translate.google.de/translate?hl=en&sl=de&u=http://www.freiberger.com/fileadmin/Download/GaAs_kompakt_Produktinfo_dt_Rev_I.pdf&prev=/search%3Fq%3DProduktinformation%2Bzu%2BGalliumarsenid%2Bkompakt%2B(nach%2BArt.%2B32%2BEG%2B1907/2006%2B(REACH))%2Bin%2B%25C3%259Cbereinstimmung%2Bmit%2Bdem%2BFormat%2Bder%2BVerordnung%2B(EG)%2BNr.%2B453/2010%2BDruckdatum:%2B18.01.2012,%2B%25C3%25BCberarbeitet:%2B18.01.2012,%2BInkrafttreten:%2B18.01.2012%2BVersion:%2BI,%2Bersetzt%2BVersion%2BH:%26biw%3D1366%26bih%3D705
Its a JV Company & subsidiary (Siemens) called Infineon and Wacker Chemicals....