MESFET's on a GaAs-on-insulator structure

MESFET's were fabricated on a GaAs-on-insulator structure which was grown by molecular beam epitaxy (MBE) on a GaAs substrate covered with a crystalline insulator film, Ca
x
Sr
1-x
F
2
. The g
m
value of 71 mS/mm was obtained for an FET with a gate length of 3 µm. Complete isolation of MESFET's by island formation of GaAs on the fluoride films was also attained for the first time using a conventional wet etching process.