Preparation method of flash memory

Abstract

The invention provides a preparation method of a flash memory, which comprises the following steps of: providing a substrate which comprises a storage area and a logic area, and sequentially forming a grid material composite layer and a dielectric layer on the substrate; etching the dielectric layer and the gate material composite layer to form a first opening in the storage region; sequentially forming a protective layer and a side wall on the side wall of the first opening; filling a word line gate layer in the first opening; removing the dielectric layer and the gate material composite layer on the substrate of the logic region, and forming a logic gate layer on the substrate of the logic region; removing the residual dielectric layer, forming a patterned hard mask layer on the storage region and the logic region in a conformal manner, and etching the logic gate layer by taking the patterned hard mask layer as a mask to form a logic gate; and etching to remove the patterned hard mask layer. The electrical performance of the flash memory is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for preparing a flash memory. Background technique [0002] Flash memory has become a research hotspot in non-volatile memory due to its convenience, high storage density, and good reliability, and flash memory is widely used in mobile and communication devices such as mobile phones, notebooks, handheld computers, and U disks. As a non-volatile memory, flash memory works by changing the critical voltage of the transistor or memory cell to control the switch of the gate channel to achieve the purpose of storing data, so that the data stored in the memory will not be interrupted by the power supply And disappeared, and flash memory is a special structure of electrically erasable and programmable read-only memory. Today, flash memory has occupied most of the market share of non-volatile semiconductor memory, becoming the fastest growing non-volatile semiconductor me...

AI Technical Summary

Problems solved by technology

Flash memory has a floating gate and a control gate. The width of the floating gate and the control gate affects the erasing and reading and writing capabilities of the flash memory, and the width of the floating gate and the control gate may be affected by the preparation process, resulting in shortening of the width of the floating gate and the control gate. , ultimately affecting the electrical performance of the flash memory

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