Flash memory storage unit and manufacturing method therefor

Abstract

The invention discloses a flash memory storage unit and a manufacturing method therefor. The manufacturing method comprises the steps of forming an active region in a substrate by preparing a shallow trench isolation part in an isolation manner, wherein a tunneling oxide layer and a silicon nitride structure are grown on the active region in sequence; reducing the width of the silicon nitride structure to form a narrowed silicon nitride structure and a narrowing region; preparing a first polysilicon structure in the narrowing region; filling the shallow trench isolation part; peeling off the narrowed silicon nitride structure to form a trench; enabling a second polysilicon structure to be grown in the trench, wherein a regular trapezoidal floating gate is formed by the second polysilicon structure and the first polysilicon structure; etching the shallow trench isolation part; preparing a silicon oxide barrier layer on the surface of the shallow trench isolation part and the side wall and the surface of the regular trapezoidal floating gate; and preparing a control gate on the silicon oxide barrier layer. The manufacturing method for the flash memory storage unit has the beneficial effects of lowering the power consumption of the floating gate device, and improving the erasing speed and reliability of the flash memory storage.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor devices, in particular to a flash memory storage unit and a manufacturing method. Background technique [0002] Flash memory (Flash Memory, referred to as flash memory) is a long-life non-volatile semiconductor memory that can still maintain stored data information in the event of a power failure. It is widely used in USB flash drives, flash memory cards, and notebook computers. , And digital cameras, mobile phones and other portable flash memory digital storage products. [0003] The prior art provides a method for manufacturing a flash memory unit. First, an oxide layer and a silicon nitride layer are sequentially formed on a substrate 1, and the oxide layer and the silicon nitride layer are used as a hard mask layer; Etching shallow trenches 2 arranged in parallel on the substrate 1 with a hard film layer, and forming a regular trapezoidal silicon nitride structure and a silicon nitr...

AI Technical Summary

Problems solved by technology

[0004] The method for making the above-mentioned flash memory storage unit has the following disadvantages: due to the instability of the etched shape of the silicon nitride layer, it is easy to cause process defects such as filling gaps in the floating gate when filling the floating gate, and this method fills the gap between the formed floating gate and the control gate. The contact area A is small, resulting in low effective coupling capacitance between the floating gate and the control gate, and the distance between the control gate and the active area is relatively close, and the parasitic coupling capacitance between the control gate and the active area is relatively high, so that the control gate cannot effectively control The opening and closing of the floating gate device causes high power consumption or even failure of the device

Images