Interfacial properties of ZrO2 on silicon

Abstract

Electrical and spectroscopic comparison of HfO 2 / Si interfaces on nitrided and un-nitrided Si (100) Yttrium silicate formation on silicon: Effect of silicon preoxidation and nitridation on interface reaction kinetics The interface of zirconium oxide thin films on silicon is analyzed in detail for their potential applications in the microelectronics. The formation of an interfacial layer of ZrSi x O y with graded Zr concentration is observed by the x-ray photoelectron spectroscopy and secondary ion mass spectrometry analysis. The as-deposited ZrO 2 /ZrSi x O y /Si sample is thermally stable up to 880°C, but is less stable compared to the ZrO 2 /SiO 2 /Si samples. Post-deposition annealing in oxygen or ammonia improved the thermal stability of as-deposited ZrO 2 /ZrSi x O y /Si to 925°C, likely due to the oxidation/nitridation of the interface. The as-deposited film had an equivalent oxide thickness of ϳ1.3 nm with a dielectric constant of ϳ21 and a leakage current of 3.2ϫ10 Ϫ3 A/cm 2 at Ϫ1.5 V. Upon oxygen or ammonia annealing, the formation of SiO x and SiH x N y O z at the interface reduced the overall dielectric constants.

Electronic structures and optical properties of monoclinic ZrO2 studied by first-principles local density approximation + U approach

“…But the experimental data of ZrO 2 films does not show a similar shoulder [30,31]. In many aspects, ZrO 2 resembles its twin oxide, HfO 2 , though it is generally believed that the electron correlations in ZrO 2 are weaker.…”

“…[1,2]. Moreover, ZrO 2 has been proven to have one of the most high dielectric constants [3] and be promising in optical and protective coatings [4,5].…”

Thermodynamic considerations in the stability of binary oxides for alternative gate dielectrics in complementary metal–oxide–semiconductors

“…Both types of interfacial layers have been reported [10,15,[24][25][26][27]. The interface between interfacial SiO 2 and the high-k layer tends to be rough, and intermixing can be difficult to distinguish from roughness [28].…”

Scanning transmission electron microscopy of gate stacks with HfO2 dielectrics and TiN electrodes

“…For example, the precise chemistry of SiO 2 -like interfacial layers formed between ZrO 2 or HfO 2 gate dielectrics and the Si substrate interface under oxidizing deposition conditions is still under debate. Electrical measurements show that the dielectric constant of these interfacial layers is greater than that of pure, bulk SiO 2 and it has been suggested that the interfacial layer is substoichiometric SiO 2 or a metal silicate [5][6][7]. Recent medium energy ion-scattering and electron energy-loss spectroscopy (EELS) studies found no evidence for silicate formation [8,9].…”