We fabricate ultra-thin HfO
2 gate stacks of very high permittivity value by using atomic layer deposition (ALD) and Ti-cap post deposition annealing. The HfO
2 layer is directly deposited on hydrophilicized Si surface by ALD. A cubic crystallographic phase is generated in ALD-HfO
2 by short time annealing with Ti capping layer. The Ti layer absorbs residual oxygen in HfO
2 layer. The reduced oxygen concentration during annealing suppresses the growth of the interfacial SiO
2 layer. The dielectric constant of ALD-HfO
2 is enhanced to ~40, and extremely scaled ~0.2 nm equivalent oxide thickness of total gate stack is obtained.
抄録全体を表示