Study of thermally grown and photo-CVD deposited silicon oxide–silicon nitride stack layers

Abstract

Silicon oxide-silicon nitride (ON) stack layers have been formed by mercury sensitized photochemical vapour deposition (photo-CVD) of silicon nitride layers over thermally grown and photo-CVD deposited silicon oxide layers on p-type Si (100) substrates. The properties of these two groups of samples were studied using Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) and capacitance-voltage measurements. Photo-CVD deposited nitrogen-rich stoichiometric silicon nitrides over thermally grown oxides give less electronic state density with an increased Si-N bond concentration, and on the other hand photo-CVD deposited oxide-nitride stacks give less fixed oxide charges. The absence of Si-H bonds in nitrides indicates that all nitrides are hydrogenated. Oxygen incorporation in the nitride layer was studied from FTIR and XPS measurements, which in turn affects the properties of these stack layers.

Characterization of SiNx/a-Si:H crystalline silicon surface passivation under UV light exposure

“…1 the IR spectra of sample P1 and N1 before UV irradiation are reported. Comparing these spectra is evident that the peaks at 820 cm − 1 , 614 cm − 1 , 1550 cm − 1 , related to N-Si 3 (asymmetric stretching mode [11]), Si-Si (stretching mode [12]), NH 2 (wagging mode [13]) respectively are higher in sample P; while the 2170 cm − 1 , relative to H-Si-HN 2 (stretching mode [14]) are higher in sample N1. Therefore it is evident that the SiN x /a-Si:H double layer composition depends on the doping type of silicon substrates on which it has been grown.…”

Study of Si3N4/SiO2/Si and SiO2/Si3N4/Si Multilayers by O and N K-Edge X-ray Absorption Spectroscopy

“…2(b), as a defect layer because the stretching out of the C-V curve indicates the presence of higher electronic state densities. 22) Considering also the NEXAFS results in Fig. 2(a), the fact that the electrical properties of the ON film with the double interface (one interface is Si 3 N 4 /SiO 2 and the another is SiO 2 /Si) is very similar to those of SiO 2 film with single interface (only SiO 2 /Si interface) means that the interface between Si 3 N 4 and SiO 2 layers is very stable.…”

“…Therefore, the larger flat band shifts could be attributed to the accumulation of positive charges at the interface. 21,22) In short, the larger negative flat band shift in NO and Si 3 N 4 film means that the interfacial positive charge in these films is trapped more predominantly, that is, the defect density is higher than in that of ON or SiO 2 film. This C-V result agrees well with the results of breakdown voltage and leakage current in Fig.…”

Cycling of implantation step and remote plasma process step for nitride spacer etching applications.

“…) the pristine SiN film contains a Si-O[3] bond at 103.6eV indicating the presence of an oxidized layer at the surface. After a 60s exposition to the hydrogen CCP discharge, the analysis reveals a modification of the surface with the formation of a new bond at 102.7eV, labelled SiN* that can be attributed to either Si-F[5] or Si-O-N [6] in figure 4b). As shown in figure 4c), Fluorine concentration is significantly increased by the implantation: although the CCP plasma is hydrogen based, the chamber's walls are contaminated with fluorine by other processes thus explaining the high amount post implantation.…”