XPS Study of the Bonding Properties of Lanthanum Oxide/Silicon Interface with a Trace Amount of Nitrogen Incorporation

Abstract

Recently, both electrical and material properties of lanthanum oxide (La2normalO3) have been found to significantly improve with a trace amount of nitrogen doping. This work conducted a detailed investigation on the nitrogen incorporation at the La2normalO3/Si interface by using X-ray photoelectron spectroscopy (XPS) and capacitance–voltage measurements. The process-dependent chemical bonding structures of Si, O, and La atoms at the interface were studied in detail. For samples annealed at 500°C and above, the interfacial metallic La–Si bonds were converted into La–N bonds, and some Si–O bonds were found at the interface. These effects resulted in a significant reduction in the interface trap density. The bulk properties of La2normalO3 were also improved with the proposed technique as a result of the filling of oxygen vacancies with nitrogen atoms.

Surface oxygen-vacancy induced photocatalytic activity of La(OH)3 nanorods prepared by a fast and scalable method

“…The high binding energy of the satellite can be ascribed to the shake-up process associated with the O 2p -La 4f charge transfer. 29 The O1s XPS spectra can be fitted with two peaks ascribing to La-O and H 2 O. 29 From Fig.…”

“…29 The O1s XPS spectra can be fitted with two peaks ascribing to La-O and H 2 O. 29 From Fig. 4b and c, the molar ratio of O/La can be determined, which is less than 3.0.…”

On the scaling of subnanometer EOT gate dielectrics for ultimate nano CMOS technology

“…Yet, amongst all these issues, the interface properties and their thermal instabilities need to be resolved firstly [64][65][66][67][68][69][70][71][72]. Transition metal (TM) or rare-earth metal (RE) based high-k dielectrics are extrinsic materials to the substrate silicon.…”

“…It was proposed that the oxygen in W may diffuse into the La 2 O 3 film to fill up the oxygen vacancies there. Oxygen vacancies are the major defect centers in La 2 O 3 which result in several instability issues and enhance the gate leakage current [59][60][61][62][63][64][65][66][67][68][69][70][71]. Post-metallization annealing may cause an reverse effect.…”

“…Most of the high-k silicides are conductive. The interfacial silicide layer would not affect the EOT but the interface metal-Si bonding is one of the interface trap precursors and results in the channel mobility degradation and in other instabilities [2,[59][60][61][62][63][64][65][66][67][68][69][70]. Most of the high-k materials, including hafnium oxide and lanthanum oxide are only marginally stable against the formation of silicates.…”