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.

Electronic structure of silicon nitride

Abstract: Silicon Nitride is found to have a valence band maximum of nitrogen lone pair p electrons because of the planar nitrogen site. This contrasts with the usual lone pair semiconductors, such as SiO2, caused by a p4 valence configuration. Consequently although the valence band density of electron states shows a lone pair band and a deeper bonding band as usual, impurities have a greater effect in the nitride than in conventional lone pair semiconductors. Hole transport is also discussed.

Memory cell incorporating a chalcogenide element and method of making same

Abstract: A memory cell incorporating a chalcogenide element and a method of making same is disclosed. In the method, a doped silicon substrate is provided with two or more polysilicon plugs to form an array of diode memory cells. A layer of silicon nitride is disposed over the plugs. Using a poly-spacer process, small pores are formed in the silicon nitride to expose a portion of the polysilicon plugs. A chalcogenide material is disposed in the pores by depositing a layer of chalcogenide material on the silicon nitride layer and planarizing the chalcogenide layer to the silicon nitride layer using CMP. A layer of TiN is next deposited over the plugs, followed by a metallization layer. The TiN and metallization layers are then masked and etched to define memory cell areas.

Large-scale silicon nitride nanophotonic phased arrays at infrared and visible wavelengths.

Abstract: We demonstrate passive large-scale nanophotonic phased arrays in a CMOS-compatible silicon photonic platform. Silicon nitride waveguides are used to allow for higher input power and lower phase variation compared to a silicon-based distribution network. A phased array at an infrared wavelength of 1550 nm is demonstrated with an ultra-large aperture size of 4 mm×4 mm, achieving a record small and near diffraction-limited spot size of 0.021°×0.021° with a side lobe suppression of 10 dB. A main beam power of 400 mW is observed. Using the same silicon nitride platform and phased array architecture, we also demonstrate, to the best of our knowledge, the first large-aperture visible nanophotonic phased array at 635 nm with an aperture size of 0.5 mm×0.5 mm and a spot size of 0.064°×0.074°.

Piezoresistance of carbon nanotubes on deformable thin-film membranes

Abstract: Carbon nanotubes have interesting electromechanical properties that may enable a new class of nanoscale mechanical sensors. We fabricated two-terminal nanotube devices on silicon nitride membranes, measured their electronic transport versus strain, and estimated their band gaps and the strain-induced changes in them. We found band-gap increases and decreases among both semiconducting and small-gap semiconducting (SGS) tubes. The SGS band gaps exceeded the predicted curvature-induced gaps for their diameter. Some of the band-gap changes for both types of tubes exceeded the predicted maxima. These anomalies are likely caused by interaction with the rough silicon nitride surface.

Statistical analysis of the intergranular film thickness in silicon nitride ceramics

Abstract: Silicon nitride materials typically reveal thin amorphous intergranular films along grain boundaries, with only the exception of special boundaries. It is known that such grain-boundary films strongly affect the high-temperature properties of the bulk material. High-resolution electron microscopy (HREM) was used to study these amorphous films in different Si[sub 3]N[sub 4] ceramics. The observed film thicknesses at grain boundaries in these materials varied between 5 and 15 [angstrom]. It was shown that the grain-boundary film thickness strongly depends on film chemistry. Careful inspections of film-thickness measurements across grain boundaries in a given material suggest that the film widths vary on the order of 1 [angstrom]. Therefore, a quantitative evaluation should allow for the determination of the standard deviation of the film thickness. The amorphous film widths along grain boundaries in four materials were measured over the entire length (up to 1 [mu]m) of the grain boundary between two triple points. Forty to fifty data points were evaluated for each boundary, giving a Gaussian-like distribution of the film thickness around a median value, which corresponded well with the film width measured from single HREM micrographs. The accuracy achieved by the statistical method was better than [plus minus] 1 [angstrom].