Material and electrical analysis of hafnium titania bilayer dielectric metal-oxide-semiconductor field-effect transistors

An approach of fabricating laminated titanium oxide on hafnium oxide bilayer dielectric has been developed for future high-performance device applications. The dielectric layers showed negligible intermixing and no silicide formation with silicon substrate. X-ray diffraction analysis demonstrated superior thermal stability (>950°C) of the hafnium titania bilayer dielectric. With the same total physical thickness of dielectric, a thicker titanium oxide layer resulted in improved electrical characteristics. It has been found that the hafnium titania bilayer dielectric metal-oxide-semiconductor field-effect transistor showed not only improved output current and transconductance, but also increased electron and hole mobility compared to hafnium binary oxide device.