Electron Energy Loss Spectroscopy Characterization of TANOS (TaN/Al₂O₃/Si₃N₄/SiO₂/Si) Stacks

Abstract

Abstract:The interfacial layer between the Al 2 O 3 layer and the Si 3 N 4 layer formed after postdeposition annealing~PDA! of TaN/Al 2 O 3 /Si 3 N 4 /SiO 2 /Si~TANOS! stacks was investigated using transmission electron microscopy~TEM!, scanning transmission electron microscopy, and electron energy loss spectroscopy~EELS!. From the result of the TEM analysis, it was found that the 2-nm-thick interface layer between Al 2 O 3 and Si 3 N 4 layers was amorphous. The high-loss EELS analysis showed that the phases of the interfacial layer weakly bound together instead of the substoichiometric silicon oxide and amorphous Al 2 O 3 near the bottom interface of the crystalline Al 2 O 3 . The low-loss EELS analysis showed that aluminum existed in metallic state at the interface. Therefore, we speculated that SiO x N y could be formed by oxidation of Si 3 N 4 during PDA and that metallic aluminum could be formed by the decomposition of weakly bound amorphous Al 2 O 3 during electron irradiation. These complicated reactions near the interface could induce oxygen deficiency in the Al 2 O 3 layer and finally degrade the retention properties of TANOS stacks.

Laser-Induced Trapping of Metastable Amorphous AlOx/C (2.5 < x ≤ 3.5) Nanocomposites: Implications for Use as Solid Phase Gas Generators

“…Specifically, the Al-L 23 edge EEL spectrum from a representative AlO x NP, as shown in the corresponding Al atom % distribution image in Figure a, reveals a unique and distinct spectral profile when compared to the standard spectrum for α-Al 2 O 3 samples. Previous articles have referred to such specific spectral peak arrangements as originating from a highly amorphous Al 2 O 3 or, in most cases, AlO x of unknown stoichiometry. − Hence, the unique EELS profile plausibly emerges from metastable oxide states trapped in laser-induced free-energy minima during the transition of Al to its stable oxide forms. Furthermore, the O–K edge EEL spectrum corresponding to the O (at.…”

Operando Characterization of Catalysts through use of a Portable Microreactor

“…In addition to the spectrum obtained with the sample loaded in the cell, a spectrum obtained in a control experiment without the sample is shown to subtract the effect caused by the SiN windows. The two strong peaks at 108 and 115 eV are associated with Si−O bonds that exhibit a transformation in response to the reaction conditions.…”

Inert ambient annealing effect on MANOS capacitor memory characteristics

“…Instead, ISPC showed a strong saturation effect of the electron charging characteristics. This must be related to the modifications of the IL layer during the PDA steps, where reports indicate that aluminum existed in a metallic phase at the interface [25]. This situation could provide leakage paths to the alumina layer that limit the nitride layer charging.…”

“…Between the Si 3 N 4 and the Al 2 O 3 an interfacial layer (IL) of 1-2 nm is evident. The unintentional growth of an IL between the nitride charge storage and the high-k blocking oxide layers has been observed quite often [15,[24][25][26] and it is attributed to the oxidation of the nitride layer either during the ALD deposition process or during the PDA step, producing thus a silicon oxynitride layer and generating oxygen deficiency conditions within the Al 2 O 3 layer [25].…”