Sio2 Plays an important role in IC technology because is acts as a diffusion mask permitting selective diffusion into silicon water through the window etched into oxide and no other semiconductor material has a he oxide which is able to active all the properties of Sio2. ● It acts as the active gate electrode in mos device structure ● It provides electrical insulation of multilavel matalization used in VLSI. ●Sio2 is used to isolate one device from another.