Split gate flash memory and manufacture method thereof

Abstract

The invention provides a split grating flash memory and a manufacture method thereof. The split gate flash memory comprises a semiconductor substrate, a gate oxide and split structure units, wherein the gate oxide is positioned on the surface of the semiconductor substrate; and the split structure units are positioned on the gate oxide. Each split structure unit is provided with a floating gate, a gate medium layer, a control gate, a first side wall layer, a second side wall layer, a third side wall layer, a word line and side walls, wherein the floating gate is positioned on the gate oxide, and the surface of the floating gate is in a cambered shape with an inclined angle; the gate medium layer is positioned on the surface of the floating gate; the control gate is positioned on the gate medium layer; the first side wall layer is positioned on the control gate; the second side wall layer is positioned on the inner side wall of the control gate; the third side wall layer is positioned in the first side wall, the second side wall layer, the gate medium layer and the inner side wall of the floating gate; the word line is positioned between two split structure units and fills a gap; and the side walls are positioned at the outside walls of the split structure units. The invention improves the performance of flash memory erasure or writing and the electric performance of the flash memory.

Description

technical field [0001] The invention relates to a flash memory, in particular to a discrete gate flash memory and a manufacturing method thereof. Background technique [0002] In recent years, the development of flash memory (flash memory for short) is particularly rapid. The main feature of flash memory is that it can keep stored information for a long time without power on; and it has the advantages of high integration, fast access speed, easy erasing and rewriting, etc., so it has been widely used in many fields such as microcomputer and automatic control. a wide range of applications. [0003] The structure of the memory cell of the flash memory is different from the conventional MOS transistor. The gate (gate) of a conventional MOS transistor and the conductive channel are separated by a gate insulating layer, generally an oxide layer (oxide); while the flash memory is on the control gate (CG: control gate, which is equivalent to the gate of a conventional MOS transis...

AI Technical Summary

Problems solved by technology

[0004] After the existing discrete gate flash memory enters the feature size of 130nm, the surface area of ​​the gate also decreases accordingly, causing the capacitance between the discrete structural units to also continue to decrease, which affects the performance of erasing or writing the flash memory

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