Abstract
Ultrathin dielectric capping layers are a prominent route for threshold voltage control in advanced Si devices. In this work the position of an Al 2O 3 layer inside a HfO 2-based stack is systematically varied and investigated following a low and a high temperature anneal. Electrical results are compared with a sub-nanometer resolution materials characterization, showing a diffusion of Al to the bottom HfO 2 interface. A correlation is found between the presence of Al at the bottom interface and a flatband voltage increase. Based on these findings, we propose to use the position of the Al 2O 3 for fine-tuning the threshold voltage.
Original language | English |
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Article number | 062907 |
Journal | Applied Physics Letters |
Volume | 100 |
Issue number | 6 |
DOIs | |
State | Published - 6 Feb 2012 |
Externally published | Yes |