Flash memory manufacturing method

Abstract

The invention discloses a flash memory manufacturing method, comprising: providing a semiconductor substrate, the semiconductor substrate including a first region and a second region; sequentially forming a first polysilicon layer and a tunnel oxide layer on the first region, Forming a second polysilicon layer on the first region and the second region; performing photolithography and etching processes on the first polysilicon layer and the second polysilicon layer on the first region to form a stacked gate structure; The second polysilicon layer is subjected to photolithography and etching processes to remove part of the memory cell area and the second polysilicon layer of the stacked gate structure on the peripheral circuit area to form the first gate structure, and in the second area forming a second gate structure; forming sidewalls on both sides of the stacked gate structure, the first gate structure and the second gate structure; and removing the sidewalls on the second region. In the invention, the second polysilicon layer is subjected to photoetching and etching processes before forming side walls, preventing polysilicon residues, and improving device performance and reliability.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a flash memory manufacturing method. Background technique [0002] Memory is used to store a large amount of digital information. Over the years, technological progress and market demand have resulted in more and more high-density various types of memory. Among them, Flash memory has long life, high integration, and high access speed. The advantages of fast, easy to erase and rewrite are widely used in various electronic products such as smart cards, SIM cards, microprocessors, and mobile phones. [0003] Generally, a typical flash memory device includes a storage area and a peripheral circuit area (periphery), wherein the storage area includes memory cells (cells), and the peripheral circuit area includes various types of transistors. In order to improve integration and process efficiency, embedded flash memory technology embeds flash memory technology into ...

AI Technical Summary

Problems solved by technology

[0011] The invention provides a flash memory manufacturing method to solve the problem that polysilicon is easy to remain at the corner of the side wall

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