Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5359400 | Applied Surface Science | 2013 | 6 Pages |
Abstract
We compared the electrical properties of HfO2, HfO2/La2O3, and La-doped HfO2 gate insulators deposited on Ge substrate using an atomic layer deposition (ALD) process. TDMAH [tetrakis(dimethylamino)hafnium] and La(iprCp)3 [tris(isopropyl-cyclopentadienyl) lanthanum] were employed as Hf and La precursors, respectively. Chemical compositions and binding structures were analyzed by X-ray photoelectron spectroscopy (XPS). Electrical properties were evaluated by capacitance-voltage (C-V) and current-voltage (I-V) measurements. We found that incorporation of La2O3 near Ge can enhance the electrical properties of Ge MOS capacitors. The best electrical properties of 50 mV of hysteresis and mid â¼1012 cmâ2 eVâ1 range interface states were found for the 400 °C-annealed HfO2/La2O3 bilayer sample. These values are significantly better than those of ALD HfO2 gate insulators on Ge. We attribute this to the formation of LaGeOx layers on the Ge surface, which reduces GeO bonding.
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Authors
Il-kwon Oh, Min-Kyu Kim, Jae-seung Lee, Chang-Wan Lee, Clement Lansalot-Matras, Wontae Noh, Jusang Park, Atif Noori, David Thompson, Schubert Chu, W.J. Maeng, Hyungjun Kim,