Improved interfacial and electrical properties of HfLaON gate dielectric Ge MOS capacitor by NbON/Si dual passivation layer and fluorine incorporation

Gemetal-oxide-semiconductor(MOS) capacitor with HfLaON/(NbON/Si) stacked gatedielectric and fluorine-plasma treatment is fabricated, and its interfacial andelectrical properties are compared with its counterparts without the Sipassivation layer or the fluorine-plasma treatment. The experimental results show that the HfLaON/(NbON/Si)GeMOS device treated by fluorine plasma exhibits excellent performance: low interface-state density (4.3  × 1011 cm−2 eV−1), small flatband voltage (0.22  V), good capacitance-voltage behavior, small frequency dispersion and low gate leakage current (4.18 × 10−5 A/cm2 at Vg = Vfb + 1 V). These should be attributed to the suppressed growth of unstableGe oxides on theGe surface during gate-dielectric annealing by the NbON/Si dual interlayer and fluorine incorporation, thus reducing the defective states at/near the NbSiON/Geinterface and improving theelectrical properties of the device.

Source: Applied Physics Letters - November 8, 2016 Category: Physics Authors: Yong Huang, Jing-Ping Xu, Lu Liu, Pui-To Lai and Wing-Man Tang Source Type: research