Poly-silicon filling method suitable for wide-size groove

Abstract

The invention provides a poly-silicon filling method suitable for a wide-size groove. The poly-silicon filling method suitable for the wide-size groove comprises the steps of performing first poly-silicon filling on the wide-size groove to form a first poly-silicon layer; oxidizing a surface of the first poly-silicon layer to form a silicon dioxide layer; respectively etching the silicon dioxide layer and the first poly-silicon layer; removing the silicon dioxide layer in the wide-size groove, wherein the effective width of the wide-size groove becomes narrow by the first poly-silicon layer filled in the wide-size groove; performing second poly-silicon filling on the wide-size groove to form a second poly-silicon layer; and etching the second poly-silicon layer to remove the second poly-silicon layer outside the wide-size groove.

Description

【Technical Field】 [0001] The present invention relates to the technical field of semiconductor chip manufacturing, and in particular, to a polysilicon filling method suitable for wide-sized trenches. 【Background technique】 [0002] In the manufacture of semiconductor chips, it is often necessary to fill the trench and re-etch the filler. However, in the process of using polysilicon as a filler for trench filling and re-etching the filler, the following phenomenon often occurs: For a trench with a larger opening size, the filling effect of the filler is worse, and the filling effect is worse. After the object is engraved back, the topography of the filler surface becomes worse, such as deep pits. Therefore, the above-mentioned problems with wide-sized trenches will bring a series of difficulties to subsequent processes. [0003] In view of this, it is necessary to provide a polysilicon filling method suitable for wide-sized trenches to solve the above-mentioned problems in the pri...

AI Technical Summary

Problems solved by technology

However, in the process of filling trenches with polysilicon as fillers and etching back the fillers, the following phenomenon often occurs: the filling effect of the fillers is poorer for trenches with larger opening sizes, and the filling After the object is etched back, the surface morphology of the filling will be worse, such as deep pits, etc.

Therefore, the above-mentioned problems for wide-sized trenches will bring a series of difficulties to subsequent processes

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