Abstract
We have investigated the device property dependence of high dielectric-constant (high-κ) TiLaO epitaxial-Ge/Si n -type metal-oxide-semiconductor (n-MOS) capacitors on different GeO 2 and SiO 2 interfacial layers. Large capacitance density of 3.3 μF/ cm 2 , small equivalent-oxide thickness (EOT) of 0.81 nm and small C-V hysteresis of 19 mV are obtained simultaneously for MOS capacitor using ultrathin SiO 2 interfacial layer, while the device with ultrathin interfacial GeO 2 shows inferior performance of larger 1.1 nm EOT and poor C-V hysteresis of 93 mV. From cross-sectional transmission electron microscopy, secondary ion mass spectroscopy, and x-ray photoelectron spectroscopy analysis, the degraded device performance using GeO 2 interfacial layer is due to the severe Ge outdiffusion, thinned interfacial GeO 2 and thicker gate dielectric after 550 °C rapid-thermal anneal.
Original language | English |
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Article number | 212105 |
Journal | Applied Physics Letters |
Volume | 95 |
Issue number | 21 |
DOIs | |
State | Published - 14 Dec 2009 |