Carrier Transportation Mechanism of the $hbox{TaN}/ hbox{HfO}_{2}/hbox{IL}/hbox{Si}$ Structure With Silicon Surface Fluorine Implantation |
| |
Authors: | Woei Cherng Wu Chao-Sung Lai Tzu-Ming Wang Jer-Chyi Wang Chih Wei Hsu Ming Wen Ma Wen-Cheng Lo Tien Sheng Chao |
| |
Affiliation: | Inst. & Dept. of Electro- Phys., Nat. Chiao-Tung Univ., Hsinchu; |
| |
Abstract: | In this paper, the current transportation mechanism of HfO2 gate dielectrics with a TaN metal gate and silicon surface fluorine implantation is investigated. Based on the experimental results of the temperature dependence of gate leakage current and Fowler-Nordheim tunneling characteristics at 77 K, we have extracted the current transport mechanisms and energy band diagrams for TaN/HfO2/IL/Si structures with fluorine incorporation, respectively. In particular, we have obtained the following physical quantities: 1) fluorinated and as-deposited interfacial layer (IL)/Si barrier heights (or conduction band offsets) at 3.2 and 2.7 eV; 2) TaN/fluorinated and as-deposited HfO2 barrier heights at 2.6 and 1.9 eV; and 3) effective trapping levels at 1.25 eV (under both gate and substrate injections) below the HfOF conduction band and at 1.04 eV (under gate injection) and 1.11 eV (under substrate injection) below the HfO2 conduction band, which contributes to Frenkel-Poole conduction. |
| |
Keywords: | |
|
|