Method for manufacturing DRAM (Dynamic Random Access Memory) capacitor

Abstract

The invention relates to a method for manufacturing a DRAM (Dynamic Random Access Memory) capacitor, which comprises the following steps of: sequentially forming a barrier layer, a first molding layer, a first isolating layer, a second molding layer, a second isolating layer and a sacrificial layer on a semiconductor substrate, and then penetrating to form a plurality of slotted holes; forming cylindrical lower electrodes in all the slotted holes; forming a side wall on the outer side of the cylindrical lower electrode; and etching the second isolating layer, the second molding layer, the first isolating layer and the first molding layer based on the side walls, wherein the left isolating layer forms a support body of the lower electrode. The side wall is used as a mask, and other molding layers and isolation layers are etched and removed, so that the support body can be simply formed, the process cost is reduced, and the production time is shortened. Even if the capacitor has a very high height-width ratio, the capacitor does not topple over, and the problem that the capacitor topples over can be fundamentally solved.

Description

technical field [0001] The present application relates to a semiconductor memory device, in particular to a method for manufacturing a DRAM capacitor. Background technique [0002] As semiconductor devices become more highly integrated, the horizontal area of ​​a unit cell on a semiconductor substrate will gradually decrease. Even though the horizontal area of ​​a unit cell on a semiconductor substrate is gradually reduced, in order to store charges in a semiconductor device, a sufficiently high capacitance of a capacitor needs to be maintained. But in order to maintain the capacitance of the capacitor, the height of the bottom electrode needs to be increased to enlarge the contact area between the bottom electrode and the dielectric layer. However, increasing the height of the bottom electrode will cause the bottom electrode to collapse because the aspect ratio (Aspect Ratio) of the bottom electrode is too high. In addition, the aspect ratio of the lower electrodes may ca...

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Problems solved by technology

[0003] The existing method is to support the capacitor. However, the formation of the support layer usually uses the ArF immersion exposure (ArFImmersion Photo) process, but this process leads to increased production costs and increased production time.

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