Extremely Scaled (similar to 0.2 nm) Equivalent Oxide Thickness of Higher-k (k=40) HfO2 Gate Stacks Prepared by Atomic Layer Deposition and Oxygen-Controlled Cap Post-Deposition Annealing

作者：Morita Yukinori^*; Migita Shinji; Mizubayashi Wataru; Ota Hiroyuki

来源：Japanese Journal of Applied Physics, 2012, 51(2): 02BA04.

DOI：10.1143/JJAP.51.02BA04

We fabricate ultrathin HfO2 gate stacks of very high permittivity by atomic layer deposition (ALD) and oxygen-controlled cap post-deposition annealing. The HfO2 layer is directly deposited on a wettability-controlled Si surface by ALD. To enhance permittivity, a cubic crystallographic phase is generated in ALD-HfO2 by short-time annealing with a Ti capping layer. The Ti layer absorbs residual oxygen in the HfO2 layer, which suppresses the growth of the interfacial SiO2 layer. The dielectric constant of ALD-HfO2 is increased to similar to 40, and a gate stack of extremely scaled equivalent oxide thickness (similar to 0.2 nm) is obtained.

• 出版日期2012-2