Semiconductor structure and method for forming semiconductor structure

Abstract

The invention provides a semiconductor structure and a method for forming the semiconductor structure. The method comprises a step of providing a substrate which comprises a core region and a high-voltage region, wherein a pad oxide layer is on the core region and the high-voltage region, a step of removing the pad oxide layer, a step of forming a first dielectric layer at least on the high-voltage region after removing the pad oxide layer, a step of forming a hard mask layer on the first dielectric layer, and a step of forming isolation structures in the core region and the high-voltage region with the hard mask layer as a mask. The pad oxide layer is removed before forming the isolation structures, the number of times of the wet etching process after the subsequent formation of the isolation structures can be effectively reduced, the reduction of the probability of the occurrence of bridging and short circuit problems is facilitated, the probability of defects in a subsequently formed gate structure is reduced, and the improvement of the performance of the formed semiconductor structure is facilitated.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] In the current semiconductor industry, integrated circuits can be divided into three main types: analog circuits, digital circuits, and digital / analog hybrid circuits. Among them, memory devices are an important type in digital circuits. Among storage devices, in recent years, flash memory (Flash Memory, referred to as a flash memory device) has attracted attention from all parties and has developed particularly rapidly. The main feature of the flash memory device is that it can keep storing information for a long time without power on; it also has the advantages of high integration, fast storage speed, and easy erasing and rewriting. Therefore, flash memory devices have been widely used in many fields such as personal computers and automatic control. [0003] With the continuous de...

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Problems solved by technology

[0005] However, in the prior art, the floating gate formed by the self-aligned polysilicon process is prone to defects, which leads to the degradation of the performance of the formed semiconductor structure.

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