Making method for storage capacitor

Abstract

A method for manufacturing a storage capacitor, comprising: forming a first dielectric layer on an insulating layer of a substrate; forming a first conductive layer on the first dielectric layer; selectively etching the first conductive layer and The first dielectric layer forms a groove, and the bottom of the groove exposes the surface of the insulating layer; a second dielectric layer is formed on the side wall of the groove; a second conductive layer is formed on the bottom of the groove and the surface of the second dielectric layer ; forming a third dielectric layer on the sidewall and above the second conductive layer in the trench; filling the third conductive layer on the first conductive layer and the third dielectric layer in the trench. The manufacturing method avoids the defect that capacitor plates collapse during the manufacturing process.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for manufacturing a storage capacitor. Background technique [0002] A DRAM storage unit generally includes a storage capacitor and a MOS transistor. The increase of its storage density needs to integrate more storage units per unit area and store more information per unit storage unit. The integration of more memory cells per unit area depends on the reduction of device size and the progress of lithography technology; for storing more information per unit memory cell, in addition to looking for high dielectric constant materials and reducing the distance between capacitor plates, most people currently use The method of increasing the surface area of ​​the plate, for example, the capacitor plate is designed in the shape of a barrel, a column, a crown, etc. to increase the area of ​​the plate. Chinese patent application No. 98118488.X proposes a meth...

AI Technical Summary

Problems solved by technology

During the baking process of the subsequent process, the air in the air gap 119a expands due to heat and explodes, causing the failure of the capacitor to be manufactured.

Reducing the depth of the groove 106a can avoid the formation of the air gap 119a, but the surface area of ​​the capacitor plate is sacrificed to reduce the capacity of the storage capacitor

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