Split-gate flash memory and method of forming the same

Abstract

The present invention provides a split-gate flash memory and a forming method thereof. The formation method of the split-gate flash memory includes: forming a first dielectric layer and a floating gate layer on the substrate in sequence; forming a separate second dielectric layer on the floating gate layer, and the area where the second dielectric layer is located is the word line area; A first sidewall is formed around the dielectric layer, and the area between adjacent first sidewalls is the source line area; using the first sidewall as a mask, the floating gate layer and the first dielectric layer are etched to the substrate; The source line is formed in the electrode line area; the second dielectric layer, the floating gate layer and the first dielectric layer under the second dielectric layer are removed to form a floating gate and a floating gate dielectric layer; on the top of the floating gate adjacent to the word line area The floating gate sidewall below the tip forms a third dielectric layer; a tunneling dielectric layer is formed to cover the substrate, the third dielectric layer, the floating gate, the first sidewall and the source line surface; the tunneling dielectric layer is formed in the word line area Word lines are formed on the top. The method of the present invention can improve the erasing performance, reduce the voltage applied on the word line and save power consumption.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a split-gate flash memory and a forming method thereof. Background technique [0002] In the current semiconductor industry, integrated circuit products can be mainly divided into three types: logic, memory and analog circuits, among which storage devices account for a considerable proportion of integrated circuit products, such as RAM (random access memory), DRAM (dynamic Random access memory), ROM (read-only memory), EPROM (erasable programmable read-only memory), FLASH (flash memory) and FRAM (ferroelectric memory), etc. The development of flash memory in memory is particularly rapid. Its main feature is that it can keep the stored information for a long time without power on. It has many advantages such as high integration, fast access speed and easy erasure, so it has been widely used in many fields such as microcomputer and automatic control. a wide range of applications. ...

AI Technical Summary

Problems solved by technology

[0013] The technical problem to be solved by the present invention is that the erasing performance of the self-aligned split-gate flash memory formed in the prior art is poor, and the voltage during the erasing operation, that is, the voltage applied to the word line is relatively high, so that the device is High power consumption during erase operation

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