Preparation of epitaxial HfO2 film (EOT=0.5 nm) on Si substrate using atomic-layer deposition of amorphous film and rapid thermal crystallization (RTC) in an abrupt temperature gradient

A new process route for preparing epitaxial dielectric films on Si substrates is proposed. It uses atomic layer deposition and rapid thermal crystallization instead of molecular beam epitaxy. The key is to create an abrupt temperature gradient along the thickness of an amorphous film by exploiting non-equilibrium heat conduction so that the film crystallizes film from the Si interface. The effectiveness of this technique was demonstrated by fabricating epitaxial HfO₂ films on Si substrates and achieving an equivalent oxide thickness of 0.5 nm. This technique has the potential to fabricate single-crystal gate dielectric structures in future MOSFETs.