Luminescence Mechanism in Amorphous Silicon Oxynitride Films: Band Tail Model or N-Si-O Bond Defects Model

Abstract

Silicon oxynitride films are one kind of important gate dielectric materials for applications in the fabrication of silicon CMOS integrated circuits (ICs), which have been widely and deeply studied. However, with the significant demand of the technologies for Si-based monolithic optoelectronic ICs, the research efforts on the optoelectronic applications of these materials have been continually increasing, particularly in the study of light emission properties and recombination mechanisms. In this paper, we first briefly outline the present photoluminescence (PL) mechanisms in amorphous silicon oxynitride (a-SiO x N y) films. Since, the PL properties and recombination processes are affected by both structural disorder and chemical disorder, the PL mechanism has been still unclear and even controversial until now. Among these various PL recombination models, the band tail states and defect state models have gained general consensus. Recently, a N-Si-O bond defect model has been reported, which depends on relative atom concentration of oxygen and nitrogen in the silicon oxynitride materials. It has been revealed that oxygen bonding plays a key role, not only in reducing the structural disorder, but also in creating N-Si-O (N x) defect states in the band gap. The characteristics of two models, namely band tail and N-Si-O bond defects, have been discussed in detail. Finally, it has been shown that by controlling the chemical composition of these non-stoichiometric silicon oxynitride materials, the optical and electronic properties can be improved. Keywords: amorphous silicon oxynitride (a-SiN x O y), PL mechanism, band tail model, N-Si-O bond defect model, a-SiN x O y LED

Critical Level of Nitrogen Incorporation in Silicon Oxynitride Films: Transition of Structure and Properties, toward Enhanced Anticorrosion Performance

“…The second most prominent component for TD12 and TD7 conditions corresponds to a tetrahedral configuration of Si-(O) 4 (103.3 and 103.1 eV, respectively), describing the silica character of the films . This component however disappears for TD11 and TD9 (Figure b,a), similar to the decrease of the Si–O–Si LO3, TO3, TO2, absorptions observed by FT-IR.…”

“…Thus, an increase in O 2 supply results in higher oxygen content in the films, accompanied by lower nitrogen incorporation that is noted to drop from 9.4 atom % N for 0.3 sccm O 2 to 4.3 atom % N for 1.2 sccm O 2 . It is noted that the O/(O+N) relative atomic concentration has been characterized as a crucial factor that influences the chemical bonding configuration and physical properties of the film . Chen et al proposed that when the O/(O+N) ratio is above 0.4, nitride-like structures in the film are transformed and lean toward oxide-like structures.…”

“…It is noted that the O/(O+N) relative atomic concentration has been characterized as a crucial factor that influences the chemical bonding configuration and physical properties of the film. 10 Chen et al proposed that when the O/(O+N) ratio is above 0.4, nitride-like structures in the film are transformed and lean toward oxide-like structures. In consequence, the electronic properties change when the SiO x N y layer is intended for gate dielectric applications.…”

“…Although this material has been widely studied due to the above outstanding properties, further investigation of the structural and chemical disorder is of essence for new upcoming applications of SiO x N y . 10 Moreover, control of the chemical composition of such films is essential. Adjustable SiO x N y film composition and, by extension, tunable properties such as refractive index or network density are often achieved by controlling the starting reaction chemistry.…”

“…Their oxygen permeability and low water vapor transmission rate is also in demand for food packaging and electronic devices, given their ability to prevent degradation or failure of chemically reactive electrodes or conductive components after exposure to humidity or oxygen. Although this material has been widely studied due to the above outstanding properties, further investigation of the structural and chemical disorder is of essence for new upcoming applications of SiO x N y . Moreover, control of the chemical composition of such films is essential.…”