Abstract
The replacement of poly-silicon by metallic compounds in the gate stack leads to the search of metals with suitable work function. However, it is observed that thermal budget has a large influence on the effective work functions of several metals, In this paper, we investigated the possible modification of the chemical states by physical analysis techniques (XPS, XRR, MEIS, TOF-SIMS) by studying the chemistry of the high-k oxide/metal interface. We show that in the case of the TiN/TaN/HfO2/SiO2/Si stack, several modifications occur upon 1000C N2annealing: Increase of the nitrogen content of the TaN, interdiffusion of the Ti and TaN, and formation of Ta2O5at the TaN/HfO2interface.
Original language | English |
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Pages (from-to) | 433-442 |
Number of pages | 10 |
Journal | ECS Transactions |
Volume | 16 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1 Dec 2008 |
Externally published | Yes |