A method of manufacturing a semiconductor device

Abstract

The present invention proposes a method for manufacturing a semiconductor device, comprising: providing a semiconductor substrate; sequentially forming a gate oxide layer and a floating gate polysilicon layer on the semiconductor substrate; forming a large-sized floating gate buffer oxide layer; dividing the large-sized floating gate buffer oxide layer into a plurality of small-sized floating gate buffer oxide layers of the same size; performing chemical mechanical polishing. The method of the present invention provides a relaxed window for subsequent processes by optimizing the pattern of the floating gate buffer oxide layer formed on the floating gate polysilicon layer located in the large-area active region after the FGBF photolithography process, to solve the problem of the floating gate polysilicon layer After CMP, recesses are formed in the floating gate polysilicon layer located in the large-area active region, so as to improve the overall performance of the embedded flash memory and the yield rate of the embedded flash memory.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for manufacturing an embedded flash memory floating gate. Background technique [0002] Memory is used to store a large amount of digital information. According to recent surveys, memory chips account for about 30% of semiconductor transactions worldwide. Over the years, technological progress and market demand have led to more and more high-density various Types of memory, such as RAM (random access memory), SRAM (static random access memory), DRAM (dynamic random access memory) and FRAM (ferroelectric memory), etc. [0003] Random access memory, such as DRAM and SRAM, has the problem of data loss after power failure during use. To overcome this problem, various nonvolatile memories have been designed and developed. Recently, flash memory based on the floating gate concept has become the most versatile non-volatile memory due to its small cell size and good per...

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Problems solved by technology

Therefore, during the CMP process, as the size of the active region increases, the recess phenomenon becomes more and more serious, and the recess will be transferred to the floating gate polysilicon layer after CMP, causing damage to the active region by the subsequent etching process.

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