The effects of process condition of top-TiN and TaN thickness on the effective work function of MOSCAP with high-k/metal gate stacks  

作　　者：马雪丽 杨红 王文武 殷华湘 朱慧珑 赵超 陈大鹏 叶甜春 

机构地区：[1]Institute of Microelectronics Chinese Academy of Sciences

出　　处：《Journal of Semiconductors》2014年第10期187-189,共3页半导体学报（英文版）

基　　金：Project supported by the Important National Science&Technology Specific Projects(No.2009ZX02035);the National Natural Science Foundation of China(Nos.61176091,61306129)

摘　　要：： We introduced a TaN/TiAl/top-TiN triple-layer to modulate the effective work function of a TiN-based metal gate stack by varying the TaN thickness and top-TiN technology process. The results show that a thinner TaN and PVD-process top-TiN capping provide smaller effective work function （EWF）, and a thicker TaN and ALD-process top-TiN capping provides a larger EWF; here, the EWF shifts are from 4.25 to 4.56 eV. A physical understanding of the dependence of the EWF on the top-TiN technology process and TaN thickness is proposed. Compared with PVD-TiN room temperature process, the ALD-TiN 400 ℃ process provides more thermal budget. It would also promote more Al atoms to diffuse into the top-TiN rather than the bottom-TiN. Meanwhile, the thicker TaN prevents the Al atoms diffusing into the bottom-TiN. These facts induce the EWF to increase.We introduced a TaN/TiAl/top-TiN triple-layer to modulate the effective work function of a TiN-based metal gate stack by varying the TaN thickness and top-TiN technology process. The results show that a thinner TaN and PVD-process top-TiN capping provide smaller effective work function （EWF）, and a thicker TaN and ALD-process top-TiN capping provides a larger EWF; here, the EWF shifts are from 4.25 to 4.56 eV. A physical understanding of the dependence of the EWF on the top-TiN technology process and TaN thickness is proposed. Compared with PVD-TiN room temperature process, the ALD-TiN 400 ℃ process provides more thermal budget. It would also promote more Al atoms to diffuse into the top-TiN rather than the bottom-TiN. Meanwhile, the thicker TaN prevents the Al atoms diffusing into the bottom-TiN. These facts induce the EWF to increase.

关 键 词：TAN ALD-TiN PVD-TiN effective work function 

分 类 号：TN386[电子电信—物理电子学] P208[天文地球—地图制图学与地理信息工程]