KR100811250B1 - Method for forming the capacitor of semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a capacitor of a semiconductor device, and in particular, deposits an interlayer insulating film and a hard mask sequentially on a semiconductor substrate having a predetermined substructure, and forms contact holes through an exposure and etching process. After the photoresist is applied, the secondary etchback process is performed to remove the hard mask to form a capacitor, which prevents damage to the bottom surface of the contact hole when the hard mask is removed, thereby shortening the lower bit line. It is a technique to remove.

Capacitors, Bridges, Cylindrical, Hardmasks

Description

Method for forming the capacitor of semiconductor device             

1 is a photograph illustrating a problem of a capacitor formed by a capacitor manufacturing method of a conventional semiconductor device.

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

 -Explanation of symbols for the main parts of the drawing-

100: semiconductor substrate 110: bit line

120: etch stop film 130: interlayer insulating film

140: hard mask 150: the first photosensitive film pattern

155: storage node contact hole forming area

160: contact hole 170: second photosensitive film

180: lower electrode of the storage node

 The present invention relates to a method of manufacturing a capacitor of a semiconductor device, and more particularly, to sequentially deposit an interlayer insulating film and a hard mask on a semiconductor substrate having a predetermined substructure, to form contact holes in an exposure and etching process, After applying the photoresist to the entire result, the secondary etch back process is performed to remove the hard mask to form a capacitor, which prevents the contact hole lower surface from being damaged when the hard mask is removed, and the short bit with the lower bit line It relates to a capacitor manufacturing method of a semiconductor device to remove the.

With the recent development of semiconductor integrated circuit process technology, the minimum line width length of devices fabricated on a semiconductor substrate is further miniaturized, and the degree of integration per unit area is increasing.

In general, a capacitor stores electric charges and supplies electric charges necessary for the operation of the semiconductor device. As the semiconductor device becomes more integrated, the capacitance of the device becomes smaller while the size of the unit cell becomes smaller. Is increasing slightly.

In the structure of the charge storage electrode of the capacitor, a large charge storage electrode is formed by stacking several layers on a narrow plane to obtain a large capacitor area, and forming a groove having a constant depth in a semiconductor substrate. Later, it is largely classified into a trench structure that forms a capacitor at the site to store charge.

In particular, the laminated structure has a fin type, fin shape, and cylinder shaped and cavity type HSG (Hemispherical Shaped Grains) and bellows, which are modified to have a cylindrical shape such as a cylinder, and a cavity type. Efforts have been made to increase the charging capacity of capacitors, which are composed of modified capacitor structures such as bellows.

1 is a cross-sectional view illustrating a problem of a capacitor formed by a capacitor manufacturing method of a conventional semiconductor device.

As illustrated in FIG. 1, an interlayer insulating layer and a hard mask are deposited on a semiconductor substrate having a predetermined substructure, and then a storage node contact hole is formed by performing an exposure and etching process.

Thereafter, after removing the hard mask, the MPS film was deposited on the resultant to grow the MPS film to form a protrusion, and a chemical mechanical polishing process was performed to form a cylindrical capacitor.

However, during the hard mask removal process, the contact hole lower interlayer insulating film is damaged as “A”, and thus, when the subsequent MPS film is formed, the protruding MPS films due to MPS growth are connected to each other to cause a bridge phenomenon.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to sequentially deposit an interlayer insulating film and a hard mask on a semiconductor substrate having a predetermined substructure, and then expose and etch the contact holes. After the photoresist is applied to the entire resultant, the secondary etchback process is performed to remove the hard mask to form a capacitor. When removing the hard mask, the lower surface of the contact hole is prevented from being damaged. The purpose is to eliminate the phenomenon of short circuit.

In order to achieve the above object, the present invention comprises the steps of sequentially depositing an interlayer insulating film and a hard mask on the semiconductor substrate on which the bit line is formed, and then forming a first photoresist layer pattern to form a storage node contact hole, and the first photoresist layer Etching the pattern using an etch mask to form a storage node contact hole, and then applying a second photoresist film to the entire resultant, removing the second photoresist film to an upper portion of the hard mask by an etch back process, and the hard Removing the mask by using the second photoresist layer as an etch barrier, and removing the second photoresist layer through a cleaning process, and depositing a storage node lower electrode forming material over the entire resultant semiconductor device. It provides a method of manufacturing a capacitor.

Preferably, the present invention is characterized in that the hard mask is made of poly.

In addition, preferably, the present invention is characterized in that the hard mask is formed of a titanium film alone, or a double film consisting of a titanium film and a titanium nitride film is formed to a thickness of 400 ~ 1000Å.

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

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

As shown in FIG. 2A, the etch stop layer 120 and the interlayer dielectric layer 130 are sequentially deposited on the semiconductor substrate 100 on which the bit lines 110 are formed. In this case, the interlayer dielectric layer 130 is formed of an oxide material. Use to deposit about 5000 ~ 20000Å.

After the deposition of the hard mask 140 having a thickness of 100 to 2000 Å at a temperature of 350 to 770 ° C. using an LPCVD method or a PECVD method using poly on the interlayer insulating layer 130, the storage node contact hole forming region 155 is formed. ) Is formed to form a first photoresist pattern 150.

Subsequently, as illustrated in FIG. 2B, the hard mask 140, the interlayer insulating layer 130, and the etch stop layer 120 are etched using the first photoresist pattern (not shown) as an etch mask. After forming), the first photoresist pattern (not shown) is removed by wet etching using BOE solution or HF solution.

Thereafter, the second photoresist layer 170 is applied to the entire resultant as an etching barrier for removing subsequent hard masks.

As shown in FIG. 2C, the second photoresist layer 170 is removed to the upper portion of the hard mask 140 by an etch back process to relieve stress applied to the lower surface of the storage node contact hole during subsequent hard mask removal etching. .

Subsequently, as shown in FIG. 2D, the second photoresist film (not shown) is etched back as an etching barrier to remove the hard mask (not shown), and then the remaining second photoresist film is removed to remove the interlayer insulating film. The contact hole 160 is left inside.

Subsequently, as illustrated in FIG. 2E, the storage node lower electrode forming material is deposited on the entire resultant to form the storage node lower electrode 180, and then a third photoresist layer (not shown) is applied to the etch barrier. The storage node lower electrode 180 is separated by performing a chemical mechanical polishing process until the upper portion of the lower interlayer insulating layer 130 is exposed.

Thereafter, the third photoresist film (not shown) is removed on the result by performing a wet cleaning process.

Therefore, as described above, when the capacitor manufacturing method of the semiconductor device according to the present invention is used, the interlayer insulating film and the hard mask are sequentially deposited on the semiconductor substrate having a predetermined substructure, followed by exposure and etching processes. After forming a contact hole and applying a photoresist to the entire product, a secondary etch back process is performed to remove a hard mask to form a capacitor, thereby preventing the contact hole from being damaged when the hard mask is removed. The effect of shorting with the line is eliminated.

Claims (4)

Sequentially forming an interlayer insulating layer and a hard mask on the semiconductor substrate on which the bit lines are formed; Etching the hard mask and the interlayer insulating layer to form a storage node contact hole; Applying a photoresist to the entire result of the formation of the storage node contact holes; Etching the photoresist to expose the hard mask; Removing the hard mask using the photoresist as a mask; Removing the photosensitive film; And And forming a storage electrode on the resultant from which the photoresist film is removed. The method of claim 1, wherein the hard mask is formed of polysilicon. delete The method of claim 1, wherein the hard mask is formed of a titanium film alone, or a double film made of a titanium film and a titanium nitride film.

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