Silicon nitride

About: Silicon nitride is a research topic. Over the lifetime, 32678 publications have been published within this topic receiving 413599 citations. The topic is also known as: N₄Si₃.

Optimised antireflection coatings for planar silicon solar cells using remote PECVD silicon nitride and porous silicon dioxide

Abstract: Silicon nitride (SiN) films fabricated by remote plasma-enhanced chemical vapour deposition (RPECVD) have recently been shown to provide an excellent electronic passivation of silicon surfaces. This property, in combination with its large refractive index, makes RPECVD SiN an ideal candidate for a surface-passivating antireflection coating on silicon solar cells. A major problem of these films, however, is the fact that the extinction coefficient increases with increasing refractive index. Hence, a careful optimisation of RPECVD SiN based antireflection coatings on silicon solar cells must consider the light absorption within the films. Optimal optical performance of silicon solar cells in air is obtained if the RPECVD SiN films are combined with a medium with a refractive index below 1·46, such as porous SiO2. In this study, the dispersion of the refractive indices and the extinction coefficients of RPECVD SiN, porous SiO2, and several other relevant materials (MgF2, TiOx, ZnS, B270 crown glass, soda lime glass, ethylene vinyl acetate and resin as used in commercial photovoltaic modules) are experimentally determined. Based on these data, the short-circuit currents of planar silicon solar cells covered by RPECVD SiN and/or porous SiO2 single- and multi-layer antireflection coatings are numerically maximised for glass-encapsulated as well as non-encapsulated operating conditions. The porous SiO2/RPECVD SiN-based antireflection coatings optimised for these applications are shown to be universally suited for silicon solar cells, regardless of the internal blue or red response of the cells. Copyright © 1999 John Wiley & Sons, Ltd.

Method to plasma deposit on organic polymer dielectric film

Abstract: A method for protecting an organic polymer underlayer during a plasma assisted process of depositing a subsequent film on the organic polymer underlayer is disclosed. The method provides the deposition of a protective continuous layer using organic polymer damage-free technique in order to not damage the organic polymer underlayer and to protect the organic polymer underlayer during the plasma assisted process of depositing a subsequent film. The organic polymer damage-free technique is a non-plasma process, using only thermal energy and chemical reactions to deposit the continuous layer. The organic polymer damage-free technique can also be a plasma assisted process using a reduced plasma power low enough in order to not damage the organic polymer underlayer. This method is applicable to many organic polymer underlayers such as organic polymer is aromatic hydrocarbon, polytetrafluoroehtylene (PTFE), parylene, benzocyclobutene-based polymers (BCB), polyimide, fluorinated polyimide, fluorocarbon-based polymers, poly(arylene ether)-based polymers (PAE), cyclohexanone-based polymers, and to many plasma assisted deposition processes such as plasma enhanced CVD deposition, plasma enhanced ALD deposition and plasma enhanced NLD deposition of silicon dioxide, silicon nitride, nitrided diffusion barrier such as TiN, TaN, WN, TiSiN, TaSiN, WSiN.

Atomic Layer Deposition of Silicon Nitride from Bis(tert-butylamino)silane and N2 Plasma.

Abstract: Atomic layer deposition (ALD) of silicon nitride (SiNx) is deemed essential for a variety of applications in nanoelectronics, such as gate spacer layers in transistors. In this work an ALD process using bis(tert-butylamino)silane (BTBAS) and N2 plasma was developed and studied. The process exhibited a wide temperature window starting from room temperature up to 500 °C. The material properties and wet-etch rates were investigated as a function of plasma exposure time, plasma pressure, and substrate table temperature. Table temperatures of 300–500 °C yielded a high material quality and a composition close to Si3N4 was obtained at 500 °C (N/Si = 1.4 ± 0.1, mass density = 2.9 ± 0.1 g/cm3, refractive index = 1.96 ± 0.03). Low wet-etch rates of ∼1 nm/min were obtained for films deposited at table temperatures of 400 °C and higher, similar to that achieved in the literature using low-pressure chemical vapor deposition of SiNx at >700 °C. For novel applications requiring significantly lower temperatures, the temp...

Progress in Low‐temperature Surface Passivation of Silicon Solar Cells using Remote‐plasma Silicon Nitride

Abstract: Using a remote-plasma technique as opposed to the conventional direct-plasma technique, significant progress has been obtained at ISFH in the area of low-temperature surface passivation of p-type crystalline silicon solar cells by means of silicon nitride (SiN) films fabricated at 350–400°C in a plasma-enhanced chemical vapour deposition system. If applied to the rear surface of the low-resistivity p-type substrates, the remote-plasma SiN films provide outstanding surface recombination velocities (SRVs) as low as 4 cm s−1, which is by a clear margin the lowest value ever obtained on a low-resistivity p-Si wafer passivated by a solid film, including highest quality thermal oxides. Compared to direct-plasma SiN films or thermally grown oxides, the remote-plasma films not only provide significantly better SRVs on low-resistivity p-silicon wafers, but also an enormously improved stability against ultraviolet (UV) light. The potential of these remote-plasma silicon nitride films for silicon solar cell applications is further increased by the fact that they provide a surface passivation on phosphorus-diffused emitters which is comparable to high-quality thermal oxides. Furthermore, if combined with a thermal oxide and a caesium treatment, the films induce a UV-stable inversion-layer emitter of outstanding electronic quality. Due to the low deposition temperature and the high refraction index, these remote-plasma SiN films act as highly efficient surface-passivating antireflection coatings. Application of these films to cost-effective silicon solar cell designs presently under development at ISFH turned out to be most successful, as demonstrated by diffused p-n junction cells with efficiencies above 19%, by bifacial p-n junction cells with front and rear efficiencies above 18%, by mask-free evaporated p-n junction cells with efficiencies above 18% and by MIS inversion-layer cells with a new record efficiency of above 17%. All cells are found to be stable during a UV test corresponding to more than 4 years of glass-encapsulated outdoor operation. © 1997 John Wiley & Sons, Ltd.