Fabrication of Si MOSFET´s using neutron-irradiated Silicon as semi-insulating substrate

The feasibility of a novel silicon-on-semi-insulating substrate structure has been demonstrated. MOS field-effect transistors (MOSFET´s) are fabricated on neutron-irradiated silicon wafers which are used as semi-insulating substrates. In order to keep the substrate semi-insulating, laser annealing is used to make the semiconducting layer, and to activate the impurities implanted in the semiconducting layer, and plasma anodization is employed to grow the gate oxide. The mobility of carrier in the channel is about 100 cm²/V . s for p-channel MOSFET´s and 300 cm²/V . s for n-channel devices. This structure has inherent advantages such as crystallographically single crystalline.