Capacitor with oxidation barrier layer and method for manufacturing the same

Abstract

The present invention provides a capacitor and a manufacturing method thereof, which are used to prevent the lower electrode from being oxidized in the subsequent heat treatment process. The capacitor includes: a lower electrode; an oxidation barrier layer formed on the lower electrode, wherein the oxidation barrier layer is formed by at least two nitride layers; a dielectric layer formed on the oxidation barrier layer; the upper electrode on the dielectric.

Description

technical field [0001] The present invention relates to methods of manufacturing semiconductor devices, especially capacitors and methods of manufacturing the same. Background technique [0002] In highly integrated semiconductor devices, such as DRAM, dielectric materials with high dielectric constants are widely used to increase capacitance. Generally speaking, as dielectric materials, metal oxide materials such as Ta 2 o 5 、TiO 2 , TaON, HfO 2 、Al 2 o 3 and ZrO 2 etc., have been developed. [0003] In highly integrated 256M or higher DRAM devices, a layer of tantalum oxide is used as a dielectric material for capacitors included in memory cells, with a dielectric constant of about 25, which is the stack dielectric layer , that is, Si of the silicon oxide layer and silicon nitride layer generally used 3 N 4 (ε=~7) / SiO 2 (ε=˜3.8) three or four times. [0004] figure 1 is a schematic structural cross-sectional view of a conventional columnar MIS capacitor on whi...

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Problems solved by technology

[0021] In addition, due to the uneven thickness of the silicon nitride layer 17b, the generation and increase of capacitor leakage current will occur.

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