Capacitor structure and manufacturing method thereof, and memory

Abstract

The invention relates to a capacitor structure, a manufacturing method thereof and a memory. The method comprises the following steps of forming a first capacitor structure on a substrate, wherein the first capacitor structure comprises a first capacitor dielectric layer, a first upper electrode and a plurality of first lower electrodes which are arranged at intervals and are of a columnar structure; the first capacitor dielectric layer at least covers the side wall of the first lower electrode, and the first upper electrode fills a gap at the outer side of the first capacitor dielectric layer; forming a second capacitor structure on the first capacitor structure, wherein the second capacitor structure comprises a second capacitor dielectric layer, a second upper electrode and a plurality of second lower electrodes arranged at intervals; the second lower electrode is of a U-shaped structure, the bottom of the second lower electrode makes contact with the top of the first lower electrode, the second capacitor dielectric layer is at least located on the surface of the second lower electrode, and the second upper electrode is located on the surface of the second capacitor dielectric layer and fills a gap at the outer side of the second capacitor dielectric layer. According to the present invention, the surface area of the dielectric layer can be effectively increased by forming the first capacitor structure and the second capacitor structure which are laminated.

Description

technical field [0001] The invention relates to the technical field of semiconductor memory devices, in particular to a capacitor structure, a preparation method thereof, and a memory. Background technique [0002] With the shrinking of the size of semiconductor storage devices, it is becoming more and more difficult to achieve the same capacitance or increase the capacitance. According to the capacitance formula, under the same dielectric material with high dielectric constant, if Capacitance needs to be increased only by increasing the surface area and / or reducing the thickness of the dielectric material layer. However, reducing the thickness of the dielectric material layer may result in excessive leakage current. [0003] Therefore, in order to meet the requirements of the memory capacitor structure, in the structural design of the capacitor, it is generally necessary to etch a deep trench on the substrate, and uniformly plate the upper and lower electrode plates and th...

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Problems solved by technology

[0004] Based on this, it is necessary to provide a capacitor structure and its preparation method, memory

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