ATTENUATED TOTAL REFLECTION SPECTRA OF NITRIDED Si[O.sub.2]/Si STRUCTURES

• Published in: Journal of applied spectroscopy 2022-09, Vol.89 (4), p.665
• Main Authors: Odzhaev, V.B, Pyatlitski, A.N, Prosolovich, V.S, Kovalchuk, N.S, Soloviev, Ya. A, Zhygulin, D.V, Shestovsky, D.V, Yankovski, Yu.N, Brinkevich, D.I
• Format: Article
• Language: English
• Subjects: Annealing; Mass spectrometry; Nitrogen; Silica; Silicon
• ISSN: 0021-9037
• DOI: 10.1007/s10812-022-01408-3

The behavior of nitrogen in silicon dioxide films on single-crystal silicon substrates was studied by attenuated total reflection (ATR) and time-of-flight secondary ion mass spectrometry. Nitrogen was introduced into a dielectric formed by pyrogenic oxidation at 850 [degrees]C in an atmosphere of wet oxygen by implantation of [N.sup.+] ions of energy 40 keV at doses of 2.5x[10.sup.14] and 1.0x[10.sup.15] [cm.sup.-2] followed by rapid thermal annealing at 1000 or 1050 [degrees]C for 15 s in air Some of the samples were nitrided during thermal annealing in an Ni atmosphere with the addition of a small amount of [O.sub.2] at 1200 [degrees]C for 120 min. It was established that the majority of N atoms diffused during the heat treatments to the Si[O.sub.2]/Si interface and accumulated near the boundary region of the oxide. ATR spectra showed an absorption band with maxima at ~2320 and 2360 [cm.sup.-1] that was probably due to vibrations of double cumulative bonds of the O=Si=N- type. These bonds formed through the interaction of N with dangling bonds at the Si-dielectric interface, as a result of which uncompensated or strained bonds were replaced by more stable ones. The resulting stronger chemical bonds prevented charge accumulation on the surface of the Si[O.sub.2]/Si interface.