KR100636918B1 - Method for fabrication capacitor in semiconductor device - Google Patents

Abstract

A method for fabricating a capacitor in a semiconductor device is provided to remove a leakage current by improving the step coverage of a conductive material. A first oxide layer(23) is formed on a semiconductor substrate(21) having a storage node contact. The first oxide layer is etched to form a first storage node region. A first conductive layer is formed on the first storage node region. A second oxide layer(29) is formed on the resultant structure. The second oxide layer is etched to form a second storage node region(31) exposing the first storage node region. A second conductive layer(33) is formed in the first storage node region and the second storage node region. The first oxide layer has higher etch selectivity than that of the second oxide layer.

Description

METHODS FOR FABRICATION CAPACITOR IN SEMICONDUCTOR DEVICE}

1 is a cross-sectional view showing a capacitor manufacturing method of a semiconductor device according to the prior art.

2 to 3 are cross-sectional views showing a capacitor manufacturing method of a semiconductor device according to an embodiment of the present invention.

The present invention relates to a method for manufacturing a capacitor of a semiconductor device, and more particularly to a method for manufacturing a capacitor of a semiconductor device capable of improving the step coverage of a conductive material.

1 is a cross-sectional view showing a capacitor manufacturing method of a semiconductor device according to the prior art.

First, as shown in FIG. 1, the first oxide layer 13 and the second oxide layer 15 are sequentially formed on the semiconductor substrate 11 on which the storage node contacts (not shown) are formed.

At this time, the first oxide film 13 is formed of a PSG film with a thickness of about 7000 to 9000 GPa, and the second oxide film 15 is formed of a PETEOS film with a thickness of about 17000 to 19000 GPa.

Next, the first oxide layer 13 and the second oxide layer 15 are etched to expose the semiconductor substrate 11 to form a storage node region 17.

In this case, the region of the first oxide layer 13 is wider than the region of the second oxide layer 15 due to the difference in etching selectivity.

Next, a conductive film 19 is formed along the pattern in which the storage node region 17 is formed, and is formed to have a thickness of 300 to 500 kW using a titanium nitride film (TiN).

Here, the interface between the first oxide layer 13 and the second oxide layer 15 in the storage node region 17 is thin because the step coverage of the conductive layer 19 is poor and is about 50 GPa or less. It is formed in thickness.

As a result, a leak-prone region A in which an electric field is concentrated during operation of the device is generated, and thus the leakage current rapidly increases as a whole. As a result, current characteristics deteriorate during the probe test process.

An object of the present invention for solving the above problems is to provide a method for manufacturing a capacitor of a semiconductor device that can suppress the increase in leakage current due to the weakened step coverage of the conductive material.

A capacitor manufacturing method of a semiconductor device of the present invention for achieving the above object comprises the steps of forming a first oxide film on a semiconductor substrate on which a storage node contact is formed; Etching the first oxide layer to form a first storage node region; Forming a first conductive layer on a surface of the first storage node region; Forming a second oxide layer on the structure; Etching the second oxide layer to form a second storage node region exposing the first storage node region; And forming a second conductive layer in the first storage node region and the second storage node region.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 to 3 are cross-sectional views illustrating a method of manufacturing a capacitor of a semiconductor device according to an embodiment of the present invention.

First, as illustrated in FIG. 2, a first oxide layer 23 is formed on a semiconductor substrate 21 on which a storage node contact (not shown) is formed.

At this time, the first oxide film 23 is formed of a PSG film having a thickness of about 7000 to 9000 GPa.

Next, the first oxide layer 23 is etched to form a first storage node region 25 by a photolithography process using a storage node mask, and a first conductive layer 27 is formed on the first oxide layer 23. Phosphorus titanium nitride (TiN) was formed to a thickness of 100 to 200 GPa.

Thereafter, the first conductive layer 27 is left only in the first storage node region 25.

At this time, the first conductive film 27 remains at a thickness of 10 to 50 kPa.

Next, as shown in FIG. 3, a second oxide layer 29 is formed on the structure. At this time, the second oxide film 29 is formed of a PETEOS film with a thickness of about 17000 to 19000 Å.

Next, the second oxide layer 29 is etched by a photolithography process using a storage node mask to form a second storage node region 31 exposing the first conductive layer 27.

In addition, a titanium nitride film TiN, which is a second conductive film 33, is formed on the surfaces of the first storage node region 25 and the second storage node region 31 to have a thickness of 200 to 300 GPa to form a storage node. .

As a result, a conductive film is formed in the first storage node region 25 to a thickness of 210 to 350 Å, and the surface area of the capacitor is increased in a subsequent process to increase the storage capacity of the capacitor.

In addition, since the deposition thickness is stably formed by improving the step coverage of the second conductive layer 33, a leak-prone region does not occur.

In a subsequent process, a dielectric film (not shown) and a plate electrode are formed on the surface of the storage node to form a capacitor having a sufficient capacitance for high integration of the semiconductor device.

As described above, the capacitor manufacturing method of the semiconductor device according to the present invention can improve the yield by improving the step characteristic of the conductive material to remove the leakage current, and to secure the capacity of the capacitor to improve the refresh characteristics of the cell transistor. It can have an effect.

In addition, a preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and changes are the following claims It should be seen as belonging to a range.

Claims (4)

Forming a first oxide film on the semiconductor substrate on which the storage node contacts are formed; Etching the first oxide layer to form a first storage node region; Forming a first conductive layer on a surface of the first storage node region; Forming a second oxide layer on the structure; Etching the second oxide layer to form a second storage node region exposing the first storage node region; And Forming a second conductive layer in the first storage node region and the second storage node region; Capacitor manufacturing method of a semiconductor device comprising a. The method of claim 1, wherein the first oxide film has a larger etching selectivity than the second oxide film. 2. The method of claim 1, wherein the first oxide film is formed to a thickness of 7000 to 9000 kPa, the second oxide film is formed to a thickness of 17000 to 19000 kPa, and the second conductive film is formed to a thickness of 200 to 300 kPa. A method for manufacturing a capacitor of a semiconductor device. The method of manufacturing a capacitor of a semiconductor device according to claim 1, wherein the first conductive film is formed to a thickness of 100 to 200 mW, and the entire surface is etched so that the thickness of 10 to 50 mW remains.

Images