Fig. 1.
(a) Schematic diagram of the experimental structure. (b) HRTEM of the sample
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Xueli Ma, Hong Yang, Wenwu Wang, Huaxiang Yin, Huilong Zhu, Chao Zhao, Dapeng Chen, Tianchun Ye. The effects of process condition of Top-TiN and TaN thickness on the effective work function of MOSCAP with high-k/metal gate stacks[J]. Journal of Semiconductors, 2014, 35(10): 106002. doi: 10.1088/1674-4926/35/10/106002
X L Ma, H Yang, W W Wang, H X Yin, H L Zhu, C Zhao, D P Chen, T C Ye. The effects of process condition of Top-TiN and TaN thickness on the effective work function of MOSCAP with high-k/metal gate stacks[J]. J. Semicond., 2014, 35(10): 106002. doi: 10.1088/1674-4926/35/10/106002.
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The effects of process condition of Top-TiN and TaN thickness on the effective work function of MOSCAP with high-k/metal gate stacks
doi: 10.1088/1674-4926/35/10/106002
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Abstract
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.-
Keywords:
- TaN,
- ALD-TiN,
- PVD-TiN,
- effective work function
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References
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