Method of forming capacitor of semiconductor device

Abstract

Disclosed is a method of forming a capacitor of a semiconductor device which can secure a desired leakage current characteristic while securing a desired charging capacitance. The inventive method of forming a capacitor of a semiconductor device comprises steps of: forming a bottom electrode on a semiconductor substrate with a storage node contact so that the bottom electrode is connected with the storage node contact; plasma-nitrifying the bottom electrode to form a first nitrification film on the surface of the bottom electrode; forming a La2O3 dielectric film on the bottom electrode including the first nitrification film; plasma-nitrifying the La2O3 dielectric film to form a second nitrification film on the surface of the La2O3 dielectric film; and forming a top electrode on the La2O3 dielectric film including the second nitrification film.

Description

technical field [0001] The present invention relates to a method of forming a capacitor of a semiconductor device; more particularly, to a method of forming a capacitor of a semiconductor device capable of ensuring leakage current characteristics and required charging capacitance at the same time. Background technique [0002] Recently, as the development of semiconductor manufacturing technology accelerates the high integration of storage products, the unit cell area is greatly reduced, and the operating voltage is also reduced. However, despite the reduced cell area, the charging capacitance required to operate the memory device must still be high enough, not less than 25fF per cell, to prevent read errors from occurring and refresh time to be reduced. [0003] Therefore, even if a three-dimensional storage electrode having a hemispherical electrode surface is used for a nitrogen oxide (NO) capacitor of a dynamic random access memory (DRAM), the capacitor uses Si deposited...

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Problems solved by technology

[0009] However, since the crystallization temperature is higher than that of Al 2 o 3 The crystallization temperature is lower, if a high-temperature thermal process of 750°C or higher is performed when the upper electrode is formed of doped polysilicon, or 600°C or higher is implemented when the upper electrode is formed of a metallic material (such as TiN) High temperature thermal process, there are still problems: HfO 2 The dielectric film is crystallized and impurities are diffused from the upper electrode into the dielectric film, so the leakage current increases

[0010] Therefore, currently Al 2 o 3 membrane and HfO 2 It is difficult for the film to be a dielectric film that can ensure the required leakage current characteristics and charging capacitance.

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