Effective work function of Pt, Pd, and Re on atomic layer deposited HfO2

Abstract

Platinum and Pd show a significant difference in work function on SiO2 and high-K materials (HfO2). The effective metal work functions for Pd, Pt, and Re on atomic layer deposited HfO2, which are different from the vacuum work function and important for device threshold voltage control, are measured by the C-V method. The difference is attributed to the dipoles at the metal/HfO2 interface, which is a result of charge transfer across the interface. Moreover, the extracted charge neutrality level and screening parameter are correlated with the phase development, film stoichiometry, and density of interface states at the metal/high-K interface.

Quantum transport in indium nitride nanowires

“…Photolithography followed by metallization of Pd/Au is processed to define four-probe contacts with equal spacing (as depicted in Fig 2a inset). Palladium (Pd) is selected as the adhesive contact metal to form ohmic electrical contacts because its work function (5.12-5.65 eV) 15,16 matches with the large electron affinity of InN (5.8 eV). nanowire presented here has a diameter of 117 nm, much larger than the Bohr radius (~4.6 nm) 28,29 , so that the electron transport reveals bulk 3D conduction.…”

Interface characterization of metal-HfO2-InAs gate stacks using hard x-ray photoemission spectroscopy

“…3(b) shows the In 2p 3/2 signal recorded at 14 keV for three different samples (all with 12 nm HfO 2 ): no metal, 6 nm W, and 5 nm Pd on top, in descending order. No substantial influence of the top metals on the shape or energy position of the spectra can be seen, despite the large differences in work function φ and electron affinity χ for W (φ = 4.55 eV), 34 Pd (φ = 5.12 eV), 35 and HfO 2 (χ = 2.2 eV). 36 This is an important observation regarding the validity of conventional XPS studies which are usually performed on samples with only a thin high-k layer, while realistic devices need a gate metal.…”

Photoelectrochemical Reduction of CO2Using Third-Generation Conjugated Polymers

“…Using such a carbon electrode might also increase the efficiency due to a better energy level alignment. Pt has a work function of~6.0eV [36] whereas the polymer has a HOMO level (valence band) of 5.5 which is higher than that of Pt. This may lead to non-efficient hole transfer to the electrode which again might explain the lower efficiency.…”