Method for forming insulating structure and semiconductor structure

Abstract

The invention discloses a method for forming an insulating structure and a semiconductor structure, in particular a method for forming a self-alignment structure of a passing gate. The method for forming the insulating structure comprises: a first step of providing a substrate, in which deep trenches filled with a silicon material and shallow trench isolators adjoined with the deep trenches are arranged inside the substrate, and a patterned pad oxide layer and a hard mask which define openings of the deep trenches together are arranged on the substrate sequentially; a step of oxidization, in which first oxide layers are formed on the surfaces of the silicon material in the deep trenches to serve as the insulating structure of the passing gate; a step of forming first silicon layers in the openings to cover the first oxide layers; and a step of removing the hard mask.

Description

technical field [0001] The present invention relates to a method of forming an insulating structure. In particular, the present invention relates to a method of forming a self-aligned insulating structure for a passing gate. Background technique [0002] In the development of the dynamic random access memory (DRAM) process, in order to increase the component density on the chip, the word line (word line) will be arranged to "pass" other deep trench capacitors that are not controlled by the word line from above, so as to Effectively improve integration. figure 1 That is, the word line passes through other deep trench capacitors not controlled by the word line from above. like figure 1 As shown, on the layout pattern, respective word lines 101 cross over the active area 102, the deep trench capacitor 103 and the shallow trench isolation (STI), wherein when the deep trench capacitor 103 has not yet been fabricated, only the shallow Trench isolation (STI) and active region 1...

AI Technical Summary

Problems solved by technology

Therefore, on the one hand, the cost of using an additional photomask to define the position of the insulating structure is saved; on the other hand, the first oxide layer and the first silicon layer can be precisely formed in a self-alignment manner. On the deep trench, the alignment problem between the insulating structure and the trench capacitor is automatically solved, and the requirement that the insulating structure can accurately cover the deep trench capacitor is perfectly met

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