Manufacturing method of semiconductor device

Abstract

The invention provides a preparation method for a semiconductor device, and the method comprises the steps: forming a protection layer on a second polycrystalline silicon layer after the second polycrystalline silicon layer is formed, and forming a second dielectric layer on the first dielectric layer after the etching of the protection layer and the second polycrystalline silicon layer, wherein the protection layer protects the second polycrystalline silicon layer from being damaged by the dry etching technology during the dry etching of the second dielectric layer and the first dielectric layer; keeping a part of the second dielectric part and a part of the first dielectric layer nearby a side wall, wherein the second dielectric layer and the first dielectric layer protect the side wall from being affected by the wet etching technology during the removing of the protection layer through the wet etching technology; and finally removing the protection layer, the first electric layer and the second dielectric layer completely through the wet etching technology. According to the invention, the method protects the side wall and the second polycrystalline silicon layer from being affected by the etching technology, and improves the performance of a device.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for preparing a semiconductor device. Background technique [0002] With the continuous development of semiconductor technology, the critical dimensions of semiconductor devices are continuously reduced. Moreover, in the prior art, double-layer polysilicon has been used to prepare double-gate interconnection devices, so that the area of ​​the device is continuously reduced. [0003] In prior art, refer to Figure 1a As shown, when preparing double-layer polysilicon, the first polysilicon gate 2 is first formed on the semiconductor substrate 1, and then the insulating layer 6 is formed on the first polysilicon gate 2, and then the first polysilicon gate 2 is formed. A sidewall 4 is formed around the gate 2 and the insulating layer 6, and then a second polysilicon gate 3 is formed on the device, thereby forming a double-gate interconnect device. In th...

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Problems solved by technology

[0007] The object of the present invention is to provide a method for preparing a semiconductor device, which solves the problem of damaging sidewalls or polysilicon gates by etching insulating layers in the prior art

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