B4-Flash with convexity grid electrode structure

Abstract

The invention relates to a non-volatile memory, in particular to a B4-Flash with a convexity grid electrode structure. The convexity grid electrode structure successively comprises a tunnel oxide layer, an electric charge storage layer, a dielectric barrier layer and a conducting layer from bottom to top, wherein the tunnel oxide layer is of a convexity type structure of which two sides of the top surface bulge to the middle; the top surface of the tunnel oxide layer is a smooth convex cambered surface; meanwhile, the electric charge storage layer is of an arch bridge shaped structure, wherein the top surface edge of the arch bridge shaped structure bulges to the middle, and two sides of the bottom surface of the arch bridge shaped structure sink to the middle; the electric charge storage layer is a graded silicon nitride layer, and the silicon nitride layer shades to the shallow energy level of silicon enrichment silicon nitride from the deep energy level of the silicon enrichment silicon nitride from bottom to top. According to the B4-Flash with the convexity grid electrode structure, tunneling from the electric charge storage layer to a substrate can be greater than the tunneling injected into the electric charge storage layer from a gate pole so as to inhibit even eliminate and erase saturation and improve erasing speed.

Description

technical field [0001] The invention relates to a nonvolatile memory, in particular to a B4-Flash with a convex gate structure. Background technique [0002] Flash memory is a kind of non-volatile memory device. Traditional flash memory uses floating gates to store data. Since polysilicon is a conductor, the charges stored in floating gates are continuously distributed. Since polysilicon is a conductor, the charge stored in the floating gate is distributed continuously. When there is a leakage channel, the charge stored on the entire floating gate is lost through this leakage channel. Therefore, the biggest obstacle limiting the ability of flash memory to scale down is that its tunnel oxide thickness cannot be continuously reduced. Because in the case of a thin tunnel oxide layer, effects such as direct tunneling and stress-induced leakage current will pose a huge challenge to the leakage control of the memory. With the widespread application of flash memory, the recently...

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Problems solved by technology

[0007] Existing problems in the existing technology: Because the existing floating gate B4-Flash technology still adopts a planar gate structure, there is a problem of erase saturation

The device structure formed by the method provided by this patent is the same as the traditional Flash structure, so during the programming process, the distribution of its power lines is the same as Figure 1 shows exactly the same, so there is still the problem of erase saturation

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