KR20020055929A - Method of forming a dual damascene pattern in a semiconductor device - Google Patents

Abstract

PURPOSE: A method of forming a metal fuse of a semiconductor device is provided to block vertical impact by forming an impact absorption layer under a metal fuse, to prevent a crack around the metal fuse by forming a dummy fuse between the metal fuses, and to improve device reliability by preventing abnormal cutting of peripheral metal fuse. CONSTITUTION: A first interlayer dielectric layer(24) is formed on a semiconductor substrate(21). A first oxide layer(27a) is formed on the first interlayer dielectric layer(24). An impact absorption layer(40) is formed on the first oxide layer. The first oxide layer is etched to leave a region of the impact absorption layer where is going to form a metal fuse. A second interlayer dielectric(27) are formed on the resultant structure by a second and third oxide layers(27b,27c). The metal fuse(29) and a dummy metal fuse(29a) are formed on the second interlayer dielectric and a third interlayer dielectric(31) is formed on the metal fuse and a dummy metal fuse. A wire(33) of the metal fuse is formed.

Description

Method for forming a metal fuse of a semiconductor device {Method of forming a dual damascene pattern in a semiconductor device}

The present invention relates to a method of forming a metal fuse of a semiconductor device, and more particularly, to a method of forming a metal fuse of a semiconductor device, which can reduce a defect by preventing an impact from being transmitted to a peripheral area when cutting a fuse.

When a defect occurs after forming a semiconductor device or when a specific device is to be replaced by another device, fuse cutting is used to disconnect electricity from the defective device or to connect to another device to reduce the defect.

Hereinafter, with reference to the accompanying drawings will be described in detail the prior art.

Referring to FIG. 1A, after forming the field oxide film 2 in the device isolation region of the semiconductor substrate 1, a predetermined process is performed to form devices such as the transistor 3. Thereafter, after forming the first interlayer insulating film 4 on the whole, a predetermined region of the first interlayer insulating film 4 is etched by an etching process to form a contact hole through which the junction of the semiconductor substrate 1 is exposed. A contact plug 5 is formed in the contact hole by filling a conductive material. When the contact plug 5 is formed, it is planarized by removing all materials on the first interlayer insulating film 4 by a chemical mechanical polishing process. Thereafter, the first metal wiring 6 is formed on the first interlayer insulating film 4 in a predetermined pattern. When the first metal wiring 6 is formed, the second interlayer insulating film 7 is formed to insulate the upper element or the metal wiring to be formed in a subsequent process, and then is subjected to chemical mechanical polishing to planarize it.

In this case, the first interlayer insulating film or the second interlayer insulating film 4 or 7 is generally formed by depositing a TEOS film of about 1000 dir, then depositing an inorganic SOG film of about 4500 kV, and then depositing a TEOS film of about 1200 kV.

Referring to FIG. 1B, a predetermined region of the second interlayer insulating layer 7 is etched to form vias through which the first metal wires 6 are exposed, and then a second contact plug 8 is formed by filling a conductive material. Chemical mechanical polishing is again performed to remove all materials on the second interlayer insulating film 7, and then the metal fuses 9 are formed together with the second metal wires 10 in a predetermined pattern. Thereafter, the third interlayer insulating layer 11, the third contact plug 12, the third metal wiring 13, and the fourth interlayer insulating layer 14 are formed on the entire upper portion.

At this time, the thickness of the insulating film formed on the upper portion of the metal fuse 9 is about 11000 kPa.

When the metal fuse 9 formed in the above structure needs to be cut off as necessary, it is difficult to set the cutting optimum conditions. In addition, since the thickness of the insulating film deposited on the metal fuse 9 is not uniform according to the portion of the semiconductor substrate 1, the cutting defect or the peripheral device or the film may be damaged depending on the thickness of the insulating film.

Referring to FIG. 2A, when the metal fuse 9 is blown by applying energy from the outside, cracks 15 may occur in the insulating layers 7 and 4 at the bottom, and such cracks may be generated in the semiconductor substrate 1 to be electrically connected. It may cause deterioration of the characteristics or failure of the device.

Referring to FIG. 2B, when the fuse is cut by external energy, an impact may be transmitted to the metal fuse formed around the cut metal fuse 9a and abnormal cutting may occur, thereby reducing the reliability of the device and causing a defect. have.

Accordingly, the present invention is to solve the above problems by forming a shock absorbing layer that can absorb the shock in the lower portion of the metal fuse to block the vertical shock, and by forming a dummy metal fuse between the metal fuse to block the side impact metal It is an object of the present invention to provide a method of forming a metal fuse of a semiconductor device which can prevent cracks from occurring around the fuse and prevent abnormal cutting of the peripheral metal fuse, thereby improving reliability of the device and reducing defects.

1A to 1B are cross-sectional views of a device for explaining a method of forming a metal fuse of a conventional semiconductor device.

2a and 2b are cross-sectional views and planar photographs of the device shown to explain the problem occurring when cutting the fuse.

3 and 3D are cross-sectional views of devices sequentially shown to explain a method of forming a metal fuse of a semiconductor device according to the present invention.

4 is a layout view after the process shown in FIG. 3C has been performed.

<Description of the symbols for the main parts of the drawings>

1, 21: semiconductor substrate 2, 22: field oxide film

3, 23: transistor 4, 24: first interlayer insulating film

5, 25: 1st contact plug 6, 26: 1st metal wiring

7, 27: second interlayer insulating film 27a: first oxide film

27b: second oxide film 27c: third oxide film

8: second contact plug 9, 29: metal fuse

9a: cut metal fuse 29a: dummy metal fuse

10, 30: 2nd metal wiring 11, 31: 3rd interlayer insulation film

12, 32: third contact plug 13, 33: third metal wiring

14, 34: fourth interlayer insulating film 15: crack

40: shock absorbing layer 41: photosensitive film pattern

A method of forming a metal fuse of a semiconductor device according to the present invention includes forming a first interlayer insulating film on a semiconductor substrate on which various elements for forming a semiconductor device are formed, forming a first oxide film on the first interlayer insulating film, and (1) forming a shock absorbing layer on the oxide film, and then leaving only the shock absorbing layer in the region where the metal fuse is to be formed; forming second and third oxide films on the whole to form a second interlayer insulating film together with the first oxide film; Forming a metal fuse and a dummy fuse on the second interlayer insulating film, which is the upper part of the absorbing layer, and forming a third interlayer insulating film on the metal fuse and the dummy metal fuse, and performing a predetermined process to form wiring of the metal fuse using metal wiring. It consists of steps.

The first oxide film or the third oxide film is formed by depositing a TEOS film, and the second oxide film is formed by depositing an inorganic SOG film. The shock absorbing layer is formed by depositing a thickness of 1800 to 2000 GPa of nitride film. Metal fuses are made of aluminum.

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

3A and 3D are cross-sectional views sequentially illustrating devices for forming a metal fuse of a semiconductor device according to the present invention. 4 is a layout view after the process shown in FIG. 3C has been performed.

Referring to FIG. 3A, after forming the field oxide film 22 in the device isolation region of the semiconductor substrate 21, a predetermined process is performed to form devices such as the transistor 23. Subsequently, after forming the first interlayer insulating layer 24 on the whole, a predetermined region of the first interlayer insulating layer 24 is etched by an etching process to form a contact hole exposing the junction of the semiconductor substrate 21. The contact hole 25 is filled with a conductive material to form the contact plug 25. When the contact plug 25 is formed, it is planarized by removing all materials on the first interlayer insulating film 24 by a chemical mechanical polishing process. Thereafter, the first metal wires 26 are formed on the first interlayer insulating layer 24 in a predetermined pattern. When the first metal wires 26 are formed, the first oxide film 27a and the layered absorption layer 40 are formed on the entire upper portion thereof, and then the photosensitive film pattern 41 is formed in a predetermined region.

At this time, the first oxide film 27a is formed by depositing a TEOS film with a thickness of about 1000 kPa, and the shock absorbing layer 40 is formed by depositing a nitride film with a thickness of about 1800-2200 kPa. The photoresist layer pattern 41 is formed only on the layered absorption layer 40 in the region where the metal fuse is to be formed in a subsequent process.

Referring to FIG. 3B, an exposed portion of the shock absorbing layer 40 is etched and removed by an etching process using the photoresist pattern 41 as an etch mask, and then the photoresist pattern 41 is removed.

Referring to FIG. 3C, the second interlayer insulating film 27 including the first to third oxide films 27a, 27b, and 27c is formed by forming the second oxide film 27b and the third oxide film 27c on the whole. Thereafter, the second interlayer insulating layer 27 in the predetermined region is etched to form vias. The via is filled with a conductive material to form a second contact plug 29 and then chemically mechanically polished to remove and planarize all materials on the second interlayer insulating layer 27. On the second interlayer insulating film 27, a second metal wiring 30, a metal fuse 29 and a dummy metal fuse 29a are formed in a predetermined pattern. In this case, the metal fuse 29 and the dummy metal fuse 29a are formed on the nitride film, which is the shock absorbing layer 40, and are formed using aluminum or the like.

In the above description, the second oxide film 27b is formed by depositing an inorganic SOG film, and the third oxide film 27c is formed by depositing a TEOS film. At this time, the step generated by the shock absorbing layer 40 is relaxed by the inorganic SOG film which is the second oxide film 27b. In addition, there is no problem in using the nitride film as the shock absorbing layer 40 because a process for forming a via or a contact hole is not performed in the lower portion of the region where the metal fuse 29 or the dummy metal fuse 29a is formed.

Referring to FIG. 3D, after forming the third interlayer insulating layer 31 over the entire surface, a predetermined region is etched to form a via, and a third contact hole 32 is formed by filling a conductive material in the via. Thereafter, the metal fuse 29 is wired to the third metal wire 33, and a fourth interlayer insulating film 34 is formed.

The dummy metal fuse 29a formed by the above process is formed between the dummy fuses 29 within the limits allowed by the design rule when forming the dummy fuse 29 to absorb the lateral shock when the dummy fuse 29 is cut. Therefore, when the dummy fuse 29 is cut, shock may be prevented from being transmitted to other dummy fuses, thereby preventing abnormal fuse cutting. In addition, when the fuse absorbs the shock absorbing layer 40 formed under the dummy fuse 29, the shock is prevented from being transmitted to the lower element, thereby preventing the occurrence of cracks and the like, thereby preventing the failure of the device.

As described above, by cutting off the impact on the peripheral metal fuse or the lower element when cutting the metal fuse to prevent abnormal cutting or cracking caused by the lateral and lower impact to prevent the occurrence of defects and improve the reliability of the process. .

Claims (5)

Forming a first interlayer insulating film on a semiconductor substrate on which various elements for forming a semiconductor device are formed; Forming a first oxide film on the first interlayer insulating film; Forming only the shock absorbing layer on the first oxide film, and then leaving only the shock absorbing layer in the metal fuse forming region; Forming a second and third oxide film over the whole to form a second interlayer insulating film together with the second oxide film; Forming a metal fuse and a dummy fuse on the second interlayer insulating layer that is over the shock absorbing layer; And forming a third interlayer insulating film on the metal fuse and the dummy metal fuse, and performing a predetermined process to form wiring of the metal fuse using metal wiring. The method of claim 1, Wherein the first oxide film or the third oxide film is formed by depositing a TEOS film. The method of claim 1, And the second oxide film is formed by depositing an inorganic SOG film. The method of claim 1, The impact absorbing layer is a metal fuse forming method of a semiconductor device, characterized in that formed by depositing a thickness of 1800 to 2000 Å nitride film. The method of claim 1, The metal fuse is a metal fuse forming method of the semiconductor device, characterized in that formed of aluminum.