Influence of oxygen diffusion through capping layers of low work function metal gate electrodes

被引：14

作者：

Chen, B ^{[1
]}

Jha, R

Lazar, H

Biswas, N

Lee, J

Lee, B

Wielunski, L

Garfunkel, E

Misra, V

机构：

[1] N Carolina State Univ, Dept Elect & Comp Engn, Raleigh, NC 27695 USA

[2] Rutgers State Univ, Dept Chem & Biol Chem, Piscataway, NJ 08854 USA

来源：

IEEE ELECTRON DEVICE LETTERS | 2006年 / 27卷 / 04期

关键词：

alloy; capping; effective work function; metal gate; MoTa; oxygen diffusion;

D O I：

10.1109/LED.2006.871184

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

This letter evaluates Ru and W capping layers for MoTa metal gate electrodes in MOS capacitor applications. The authors report that the oxygen diffusion from the capping layer plays an important role in determining the MoTa alloy effective work function value On SiO2. A MoTa alloy metal gate with Ru capping exhibits stable effective work function up to 900 degrees C annealing but is not stable with W capping. Auger electron spectroscopy and Rutherford backscattering spectroscopy analyses show minimal oxygen diffusion into MoTa gate stacks with Ru capping while severe oxygen diffusion into the gate is observed with W capping metal after 900 degrees C annealing. Current-voltage analysis also demonstrates different barrier heights of MoTa on SiO2 with Ru or W capping layer after 900 degrees C annealing, confirming the effective work function value change.

引用

页码：228 / 230

页数：3

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