Flash memory and method of forming the same

Abstract

A flash memory and its forming method, the flash memory includes: a semiconductor substrate, the semiconductor substrate includes an erasing area, a floating gate area and a word line bit line area, the floating gate area is located on both sides of the erasing area and is connected to the erasing area The area is adjacent, the word line bit line area is located on both sides of the erasing area and the floating gate area and is adjacent to the floating gate area; the erasing gate structure located on the erasing area of ​​the semiconductor substrate; the floating gate area located on the floating gate area of ​​the semiconductor substrate Gate structure; sidewalls and the first word line structure arranged in parallel on the floating gate structure, the floating gate structure and the sidewalls cover the sidewalls of the erasing gate structure, and the sidewalls are located on the erasing gate structure and the first word line structure Between a word line structure; the second word line structure located on the word line bit line region of the semiconductor substrate, the second word line structure covers the sidewall of the first word line structure, and the second word line structure and the first word line structure electrically connected, the second word line structure includes a second word line oxide layer covering the sidewall of the floating gate structure and the surface of the semiconductor substrate. The performance of the flash memory is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a flash memory and a forming method thereof. Background technique [0002] Flash memory is an important device in integrated circuit products. The main feature of flash memory is that it can keep stored information for a long time without applying voltage. Flash memory has the advantages of high integration, fast access speed and easy erasing, so it is widely used. [0003] Flash memory is classified into two types: stack gate flash memory and split gate flash memory. The stacked gate flash memory has a floating gate and a control gate above the floating gate. The stacked gate flash memory has the problem of over-erasing. Different from the stacked gate flash memory, the split gate flash memory forms a word line as an erasing gate on one side of the floating gate. The split-gate flash memory can effectively avoid the over-erasing effect. [0004] Improving the cou...

AI Technical Summary

Problems solved by technology

Stacked-gate flash memory has the problem of over-erasing

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