KR20010003753A - Capacitor of semiconductor device and method of forming the same - Google Patents

Abstract

PURPOSE: A capacitor of a semiconductor device is provided to effectively increase a surface area of a storage electrode while preventing problems arising from a step difference, by forming the storage electrode with a plurality of cavity-type cylinders within a limited height. CONSTITUTION: A capacitor of a semiconductor device comprises the first and second cavity-type external cylindrical electrodes(12A,12B) and the first and second storage electrodes(100A,100B). The first and second cavity-type external cylindrical electrodes are separated from each other. The first and second storage electrodes further comprise the first and second cavity-type internal cylindrical electrodes(15A,15B) which are respectively established inside the first and second cavity-type external cylindrical electrodes while separated from the first and second cavity-type external cylindrical electrodes by a predetermined interval.

Description

Capacitor of semiconductor device and method of forming the same {Capacitor of semiconductor device and method of forming the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for forming a capacitor of a semiconductor device capable of sufficiently securing a capacitor capacity due to high integration.

As the degree of integration of memory elements increases, the cell area and the spacing between cells decrease, while the capacitors must have a certain capacity, so a capacitor having a large capacity in a small area is required. In order to secure such a capacitor capacity, the storage electrode is formed in a cylinder or hollow cylinder structure. In addition, the surface area of the MPS film (Mopological Poly Silicon) was further increased on the surface of the storage electrode having the above-described structure.

However, since the storage electrode of the above structure has to increase the height of the capacitor in order to secure the capacitor capacity due to high integration, there is a problem in that the process margin due to the step difference is reduced, and the storage electrode of the hollow cylinder structure The profile of the upper edge of the cylinder is not uniform, not only causes leakage current but also collapses in a subsequent process. Therefore, since the height limit is hard to form the storage electrode of the above structure, there is a limit in securing the capacitor capacity due to the high integration.

In addition, when the MPS film is applied to the storage electrode having the above-described structure, the MPS film is easily dropped and particles are generated, and the probability of causing a bridge between the storage electrodes is increased.

Accordingly, an object of the present invention is to provide a capacitor and a method for forming the semiconductor device capable of securing a sufficient capacitor capacity corresponding to high integration at a limited height.

1 is a plan view showing a storage electrode of a capacitor of a semiconductor device according to an embodiment of the present invention.

2A to 2I are cross-sectional views illustrating a method of forming a capacitor of a semiconductor device in accordance with an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

10 semiconductor substrate 11 interlayer insulating film

12, 15, and 17: first to third polysilicon films

12A, 12B: first and second hollow outer cylinder electrodes

15A, 15B: first and second hollow inner cylinder electrodes

17A, 17B: first and second cylinder electrodes

18A, 18B: first and second connection electrodes

13A, 13B: first and second trench

14, 16: first and second oxide films 18: fourth polysilicon film pattern

100A, 100B: first and second storage electrodes

19/20 MPS film / dielectric film 21 plate electrode

In order to achieve the above object of the present invention, the storage electrode of the capacitor of the semiconductor device according to the present invention, the first and second hollow outer cylinder electrode and spaced apart from each other, the first and second hollow outer cylinder electrode At least one first and second hollow inner cylinder electrodes disposed in the first and second hollow outer cylinder electrodes, respectively, and spaced apart from the first and second hollow inner cylinder electrodes, and spaced apart from the first and second hollow inner cylinder electrodes. First and second cylinders disposed at the centers of the first and second hollow inner cylinders, respectively; first connecting electrodes connecting the first hollow outer and inner cylinder electrodes and the first cylinder to each other; And a second connection electrode connecting the outer and inner cylinder electrodes and the second cylinder to each other.

In addition, the method of forming a capacitor of a semiconductor device according to the present invention comprises the steps of: forming a first polysilicon film on a semiconductor substrate on which an interlayer insulating film is formed; Etching the first polysilicon film by a predetermined depth to form first and first trenches; Sequentially forming a first oxide film, a second polysilicon film, a second oxide film, and a third polysilicon film on a surface of the first polysilicon film on which first and second trenches are formed; The first and second hollows insulated from each other by etching the third polysilicon film, the second oxide film, the second polysilicon film, and the first oxide film so that the surfaces of the first polysilicon films on the first and second trenches are exposed. Forming first and second cylinder electrodes disposed at the centers of the mold inner cylinder electrode and the first and second hollow inner cylinder electrodes, respectively; Forming a fourth polysilicon film pattern on the first and second hollow inner cylinder electrodes, the first and second cylinder electrodes, and a portion of the first and second oxide films; Etching the fourth polysilicon layer pattern and the first polysilicon layer on both sides of the first and second hollow inner cylinder electrodes to expose the interlayer insulating layer, thereby surrounding the first and second hollow inner cylinder electrodes, respectively; A first connecting electrode and a second hollow outer and inner cylinder electrode and a second cylinder connecting the first hollow outer and inner cylinder electrodes and the first cylinder electrode simultaneously with forming a first and a second hollow outer cylinder electrode; Forming a second connection electrode connecting the electrodes; Removing the first and second oxide films to form first and second storage electrodes; Forming an MPS film on surfaces of the first and second storage electrodes; Forming a dielectric film on the MPS film; And forming a plate electrode on the front surface of the substrate.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention.

1 is a plan view illustrating a storage electrode of a capacitor of a semiconductor device according to an exemplary embodiment of the present invention, and FIGS. 2A to 2I are cross-sectional views illustrating a method of forming a capacitor of a semiconductor device to which the storage electrode is applied. It is sectional drawing along the II-II 'line | wire.

As shown in FIG. 1, the first and second storage electrodes 100A and 100B of the capacitor according to the present invention are arranged with the first and second hollow outer cylinder electrodes 12A and 12B spaced apart from each other. At least one first and second hollow inner cylinder electrodes 15A disposed in the first and second hollow outer cylinder electrodes 12A and 12B, respectively, and spaced apart from the outer cylinder electrodes 12A and 12B by a predetermined distance. 15B). That is, this embodiment shows a case where one hollow inner cylinder electrode 15A, 15B is provided. In addition, the centers of the first and second hollow inner cylinder electrodes 15A and 15B are spaced apart from the first and second hollow inner cylinder electrodes 15A and 15B by a predetermined distance, and the first and second cylinder electrodes 17A, 17B) are disposed respectively, and first and second connection electrodes 18 for connecting them are disposed at upper portions of the first and second cylinder electrodes 12A, 15A, 17A, 12B, 15B, and 17B, respectively. .

Next, a method of forming a storage electrode having the above-described structure will be described with reference to FIGS. 2A to 2I.

Referring to FIG. 2A, a first polysilicon film 12 is formed on the semiconductor substrate 10 on which the interlayer insulating film 11 is formed. Here, the interlayer insulating film 11 is provided with a capacitor contact hole (not shown) for exposing a portion of the substrate 10, the first polysilicon film 12 is in contact with the substrate 10 through the contact hole. Then, the first polysilicon film 12 is etched to a predetermined depth to form the first and second trenches 13A and 13B as shown in FIG. 2B.

Referring to FIG. 2C, the first oxide film 14 is formed on the surface of the first polysilicon film 12 having the first and second trenches 13A and 13B formed thereon, and the second polysilicon film ( 15). Then, as shown in FIG. 2D, the second oxide film 16 and the third polysilicon film 17 are sequentially formed on the second polysilicon film 15, and as shown in FIG. 2E. The third polysilicon film 17, the second oxide film 16, and the second polysilicon to expose the surface of the first polysilicon film 12 on the first and second trenches 13A and 13B (see FIG. 2B). The film 15 and the first oxide film 14 are etched by chemical mechanical polishing (CMP) so that the first and second hollow inner cylinder electrodes 15A, 15B and the first and the first insulating films are insulated from each other. The first and second cylinder electrodes 17A, 17B disposed in the center of the two hollow inner cylinder electrodes 15A are formed, respectively.

Referring to FIG. 2F, a fourth polysilicon film is deposited and patterned on the structure of FIG. 2E to form the first and second hollow inner cylinder electrodes 15A and 15B and the first and second cylinder electrodes 17A and 17B. ) And a fourth polysilicon film pattern 18 on portions of the first and second oxide films 14 and 16. Referring to FIG. 2G, the interlayer insulating film 11 exposes the fourth polysilicon film pattern 18 and the first polysilicon film 12 on both sides of the first and second hollow inner cylinder electrodes 15A and 15B. Etched so as to form the first and second hollow outer cylinder electrodes 12A, 12B surrounding the first and second hollow inner cylinder electrodes 15A, 15B and simultaneously with the first hollow outer and inner cylinders. The first connecting electrode 18A connecting the electrodes 12A and 15A and the first cylinder electrode 17A and the second hollow outer and inner cylinder electrodes 12B and 5B to the second cylinder electrode 17B are connected. The second connection electrode 18B is formed.

As shown in FIG. 2H, the first and second oxide layers 14 and 16 are removed to form the first and second storage electrodes 100A and 100B.

Thereafter, in order to increase the surface areas of the first and second storage electrodes 100A and 100B, an MPS film is formed on the surfaces of the first and second storage electrodes 100A and 100B, as shown in FIG. 2I. (19) is formed and the dielectric film 20 is formed thereon, and then the plate electrode 21 is formed on the entire surface of the substrate.

According to the present invention described above, since the storage electrode is composed of a plurality of hollow cylinders within a limited height without increasing the height of the storage electrode, it is possible to effectively increase the surface area of the storage electrode while preventing problems due to the step difference. have.

In addition, by applying the MPS film within a limited height, it is possible to maximize the surface area of the storage electrode while preventing particle generation and bridge generation between the storage electrodes as in the prior art.

As a result, it is possible to sufficiently secure the capacitor capacity due to the high integration.

In addition, this invention is not limited to the said Example, It can variously deform and implement within the range which does not deviate from the technical summary of this invention.

Claims (4)

First and second hollow outer cylinder electrodes spaced apart from each other, A first having at least one first and second hollow inner cylinder electrodes spaced apart from the first and second hollow outer cylinder electrodes at predetermined intervals and disposed inside the first and second hollow outer cylinder electrodes, respectively; And a second storage electrode. The first and second storage electrodes of claim 1, wherein the first and second storage electrodes are disposed at the centers of the first and second hollow inner cylinders, respectively, and spaced apart from the first and second hollow inner cylinder electrodes. With two cylinders, And a first connection electrode connecting the first hollow outer and inner cylinder electrodes and the first cylinder to each other, and a second connection electrode connecting the second hollow outer and inner cylinder electrodes and the second cylinder to each other. Capacitor for a semiconductor device comprising a. Forming a first polysilicon film on a semiconductor substrate on which an interlayer insulating film is formed; Etching the first polysilicon layer to a predetermined depth to form first and first trenches; Sequentially forming a first oxide film, a second polysilicon film, a second oxide film, and a third polysilicon film on a surface of the first polysilicon film on which the first and second trenches are formed; The first and second insulating layers are insulated from each other by etching the third polysilicon layer, the second oxide layer, the second polysilicon layer, and the first oxide layer so that the surfaces of the first polysilicon layers on the first and second trenches are exposed. Forming first and second cylinder electrodes disposed in the center of the hollow inner cylinder electrode and the first and second hollow inner cylinder electrodes, respectively; Forming a fourth polysilicon film pattern on a portion of the first and second hollow inner cylinder electrodes, the first and second cylinder electrodes, and the first and second oxide films; The fourth polysilicon layer pattern and the first polysilicon layer on both sides of the first and second hollow inner cylinder electrodes are etched to expose the interlayer insulating layer, thereby surrounding the first and second hollow inner cylinder electrodes, respectively. The first connection electrode and the second hollow outer and inner cylinder electrode and the first connecting electrode for connecting the first hollow outer and inner cylinder electrode and the first cylinder electrode at the same time forming the first and second hollow outer cylinder electrode Forming a second connecting electrode connecting the two cylinder electrodes; And Forming the first and second storage electrodes by removing the first and second oxide films. 4. The method of claim 3, further comprising: forming an MPS film on surfaces of the first and second storage electrodes; Forming a dielectric layer on the MPS layer; And And forming a plate electrode on the front surface of the substrate.