Effective work function modification of atomic-layer-deposited-TaN film by capping layer

作者：K. Choi, Husam N. Alshareef, H.C. Wen, H. R. Harris, H.F. Luan, Y. Senzaki, Patrick Lysaght, P. Majhi, B. H. Lee · 发表于：Applied Physics Letters · 年份：2006 · DOI：10.1063/1.2234288 · 被引用次数：45 · 研究领域：Semiconductor materials and devices、Advancements in Semiconductor Devices and Circuit Design、Metal and Thin Film Mechanics

We demonstrate that the metallic capping layer has a strong impact on the effective work function (EWF) of the metal gate. Specifically, the EWF of atomic-layer-deposited (ALD)-TaN could be increased from 4.5to4.8eV with chemical-vapor-deposited-TiN capping, which is sufficient amount of work function modification for silicon on insulator based devices. A strong interdiffusion of Ti atoms into the ALD-TaN film is observed and correlated well with the changes in the EWF change. Ti capping experiments confirm that the Ti interdiffusion can actually modify the EWF of Ti/ALD-TaN stack.