No abstract

The effects of TaON/LaON dual passivation interlayer on the interfacial and electrical properties of Ge metal-oxide-semiconductor (MOS) capacitor with HfO 2 gate dielectric are investigated. As compared to its counterpart with only LaON as passivation interlayer, the formation of HfGeO x and LaHfO x , which would degrade the interfacial quality, is effectively suppressed due to the strong blocking role of the TaON barrier layer against Hf diffusion. As a result, excellent interfacial and electrical properties are achieved for the Ge MOS device with the TaON/LaON dual passivation interlayer: high k value (20.9), low interface-state density (5.32 Â 10 11 cm À2 eV À1) and oxide-charge density (À3.90 Â 10 12 cm À2), low gate leakage current density (1.77 Â 10 À4 A/cm 2 at V g ¼ V fb þ 1 V), and high reliability under high-field stress. Published by AIP Publishing.

InGaAs metal-oxide-semiconductor (MOS) capacitors with composite gate dielectric consisting of Ti-based oxynitride (TiON)/Ta-based oxynitride (TaON) multilayer are fabricated by RF sputtering. The interfacial and electrical properties of the TiON/TaON/InGaAs and TaON/TiON/InGaAs MOS structures are investigated and compared. Experimental results show that the former exhibits lower interface-state density (1.0 × 1012 cm−2 eV−1 at midgap), smaller gate leakage current (9.5 × 10−5 A/cm2 at a gate voltage of 2 V), larger equivalent dielectric constant (19.8), and higher reliability under electrical stress than the latter. The involved mechanism lies in the fact that the ultrathin TaON interlayer deposited on the sulfur-passivated InGaAs surface can effectively reduce the defective states and thus unpin the Femi level at the TaON/InGaAs interface, improving the electrical properties of the device.

Nitrided Y2O3 (YON) interfacial passivation layer (IPL) is used to passivate the HfO2/Ge interface for better interfacial and electrical properties of Ge metal-oxidesemiconductor (MOS) capacitor. Two different approaches were used to prepare the YON IPL, one is to deposit YON directly by sputtering Y2O3 target in Ar+N2 ambient, and the other is to deposit YN first by sputtering Y target in Ar+N2 ambient followed by the annealing in N2+O2 to convert YN to YON. Experimental results indicate that the MOS capacitor fabricated by the latter approach could achieve more excellent interfacial and electrical properties due to more effective suppression of the formation of Ge oxides.