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.

Silicon carbide CMOS channel

Abstract: A method for fabricating a semiconducting device on a substrate, where the improvement includes forming a strained silicon carbide channel layer on the substrate. A silicon layer is formed on top of the strained silicon carbide channel layer. A gate insulation layer is formed on top of the silicon layer and strained silicon carbide channel layer, at a temperature that does not exceed about eight hundred centigrade. A gate electrode is formed on top of the gate insulation layer, and the gate electrode is patterned. A low dose drain dopant is impregnated into the substrate, and activated with a first laser anneal. A source drain dopant is impregnated into the substrate, and activated with a second laser anneal. After the step of activating the low dose drain dopant with the first laser anneal, an insulating layer is formed around the gate electrode, at a temperature that does not exceed about eight hundred centigrade, and a spacer is formed around the gate electrode. The spacer is formed of a material that is reflective to the second laser anneal. Thus, standard materials for the spacer, such as silicon oxide or silicon nitride are not preferred for this application, because they tend to be transparent to the laser beam emissions.

Direct inkjet printing of Si3N4: Characterization of ink, green bodies and microstructure

Abstract: Direct inkjet printing of aqueous ceramic suspensions with high solid content was carried out for generating ceramic layers as well as 3D-components. In this study, silicon nitride (LPS-Si 3 N 4 ) was suspended with organic additives in an aqueous medium. Subsequently the suspension was adapted to this manufacturing technique concerning particle size and deflocculation. Thin layers and micro-scaled 3D-components, e.g. gearwheels and engineering parts, were generated and pressureless sintered. Mechanical properties (fracture toughness K Ic , hardness) and microstructure of printed LPS-Si 3 N 4 were evaluated. Results show that dense structures with good mechanical properties were obtained. No delamination or other flaw-like textures were observed. The high potential for direct inkjet printing to manufacture high performance silicon nitride ceramics is thus demonstrated.

Role of Microstructure in Hertzian Contact Damage in Silicon Nitride: I, Mechanical Characterization

Abstract: In this Part I of a two-part study of Hertzian indentation in silicon nitride we characterize irreversible contact damage as a function of microstructure. Three controlled silicon nitride microstructures are examined, representing a progression toward greater long-crack toughness: fine (F), bimodal with predominantly equiaxed α grains; medium (M), bimodal with mostly β grains of intermediate size; and coarse (C), with almost exclusively elongated β grains. An effect of increasing the microstructural heterogeneity in this sequence is to suppress ring cracking around the indenter, ultimately to a degree beyond that expected from increased toughness alone. Along with the crack suppression is a parallel tendency to enhanced damage accumulation beneath the indenter, such that the contact in the coarsest microstructure is predominantly quasi-plastic. The characterization of damage includes the following: determination of indentation stress-strain curves, to measure the level of quasi-plasticity; measurement of threshold loads for the initiation of ring cracking and subsurface yield, to quantify the competing damage processes; and measurement of characteristic dimensions of the ensuing cracks and deformation zones in their well-developed stages. These quantitative results are considered in terms of formal contact mechanics, along with finite element modeling to generate the essentially elastic-plastic fields in the different silicon nitride structures. This contact mechanics description serves also as the basis for subsequent analysis of strength degradation in Part II. Implications concerning microstructural design of silicon nitride ceramics for specific applications, notably bearings, are considered.

Densification and mechanical properties of titanium diboride with silicon nitride as a sintering aid

Abstract: Titanium diboride (TiB2) was hot-pressed at a temperature of 1800°C, and silicon nitride (Si3N4) was added as a sintering aid. The amount of Si3N4 that was added had a significant influence on the sinterability and mechanical properties of the TiB2. When a small amount (2.5 wt%) of Si3N4 was added, the Si3N4 reacted with titania (TiO2) that was present on the surface of the TiB2 powder to form titanium nitride (TiN), boron nitride (BN), and amorphous silica (SiO2). The elimination of TiO2 suppressed the grain growth effectively, which led to an improvement in the densification of TiB2. The formation of SiO2 also was deemed beneficial for densification. The mechanical properties-especially, the flexural strength-were enhanced remarkably through these improvements in the sinterability and microstructure. On the other hand, when a large amount (greaterthan equal to5 wt%) of Si3N4 was added, the mechanical properties were not improved much, presumably because of the extensive formation of a glassy Si-Ti-O-N phase at the grain boundaries.

Method and apparatus for forming silicon nitride film

Abstract: Provided is a method of forming a silicon nitride film on a surface to be processed of a target object, which includes: repeating a first process a first predetermined number of times, the process including supplying a silicon source gas containing silicon toward the surface to be processed and supplying a decomposition accelerating gas containing a material for accelerating decomposition of the silicon source gas toward the surface to be processed; performing a second process of supplying a nitriding gas containing nitrogen toward the surface to be processed a second predetermine number of times; and performing one cycle a third predetermined number of times, the one cycle being a sequence including the repetition of the first process and the performance of the second process to form the silicon nitride film on the surface to be processed.