Flash memory unit and formation method thereof

Abstract

The invention discloses a flash memory unit and a formation method thereof. The flash memory unit comprises a substrate, a floating gate, a source line doping area, a second dielectric layer, a control gate, a first side wall, a third dielectric layer, word lines and a bit line doping area, wherein the surface of the substrate is provided with a first dielectric layer, the floating gate is located on the surface of the first dielectric layer, a second opening is formed inside the floating gate, the source line doping area is located at the position, at the bottom of the second opening, inside the substrate, the second dielectric layer is located on the surface of the floating gate and arranged on the surface of the position, at the bottom of the second opening, of the substrate, the control gate is located on the surface of the second dielectric layer, the first side wall is located on the surface of the side wall of the control gate, the third dielectric layer is located on the surface of the side wall of the floating gate, the word lines are located on the two sides of the first side wall, the two sides of the control gate, the two sides of the floating gate and the two sides of the third dielectric layer, and the bit line doping area is located inside the position, on the two sides of the first side wall, the two sides of the control gate, the two sides of the floating gate and the two sides of the word lines, of the substrate. The size of the formed flash memory unit is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a flash memory storage unit and a forming method thereof. Background technique [0002] In the current semiconductor industry, integrated circuit products can be mainly divided into three types: analog circuits, digital circuits and digital / analog hybrid circuits, among which storage devices are an important type of digital circuits. In recent years, among storage devices, flash memory (flash memory) has developed particularly rapidly. 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] figure 1 It is a schematic cross-sectional structure diagram of an existing flash storage unit, i...

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Problems solved by technology

[0004] However, the size of the existing flash memory storage unit is large, and it is difficult to further reduce the size

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