KR20080027078A - Fuse box of semiconductor device and method for forming the same - Google Patents

Abstract

A fuse box of a semiconductor device and a forming method thereof are provided to prevent a crack produced at a blowing process from proceeding to an adjacent fuse. A lower structure is formed on a semiconductor substrate(31), and a first interlayer dielectric(32) is formed to cover the lower structure. A second interlayer dielectric(34) is formed on the first interlayer dielectric, and a fuse(37) composed of a TiN layer(35) and a polysilicon layer(36) is formed on the second interlayer dielectric. A third interlayer dielectric(38) is formed on the second interlayer dielectric comprising the fuse. A contact plug(39) is formed in the third and second interlayer dielectrics, and has a width larger than that of the fuse to penetrate the fuse. A metal interconnection(40) is formed on the third interlayer dielectric to be connected to the contact plug.

Description

Fuse box of semiconductor device and method for forming thereof {FUSE BOX OF SEMICONDUCTOR DEVICE AND METHOD FOR FORMING THE SAME}

1 is a cross-sectional view for explaining a fuse box of a semiconductor device according to the prior art.

Figure 2 is a photograph of a semiconductor device showing a conventional problem.

3A to 3B are cross-sectional views illustrating a fuse box of a semiconductor device in accordance with an embodiment of the present invention.

4A to 4F are cross-sectional views of processes for describing a method of forming a fuse box of a semiconductor device according to an exemplary embodiment of the present invention.

5 is a cross-sectional view of a semiconductor device for explaining the effects of the present invention.

* Description of the symbols for the main parts of the drawings *

31 semiconductor substrate 32 first interlayer insulating film

33: bit line 34: second interlayer insulating film

35 TiN film 35a Oxidized TiN film

36 polysilicon film 37 fuse

38: third interlayer insulating film 39: contact plug

40: metal wiring

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuse box of a semiconductor device and a method of forming the same, and more particularly, to a fuse box and a method of forming a semiconductor device capable of preventing a failure of an adjacent fuse due to a crack.

A semiconductor device mainly includes a fabrication (FAB) process of repeatedly forming a circuit pattern set on a silicon substrate to form cells having an integrated circuit, and packaging the substrate on which the cells are formed in a chip unit (Chip). Packaging and assembly process. In addition, a process for inspecting electrical characteristics of cells formed on the substrate is performed between the fabrication process and the assembly process.

The inspection step is a step of determining whether the cells formed on the substrate have an electrically good state or a bad state. This is to reduce the effort and cost consumed in the assembly process by removing the cells having a bad state through the inspection process before performing the assembly process. In order to detect the cells having the defective state at an early stage and regenerate them through a repair process.

Here, the repair process will be described in more detail as follows.

Redundancy cells are added to replace defective devices or circuits in the design of devices for the purpose of improving the manufacturing yield of devices in the event of a defect in the semiconductor device manufacturing process, and connecting such extra cells to the integrated circuit. In order to make a fuse together, the repair process is a process in which a cell, which has been found to be defective through an inspection process, is connected to a spare cell embedded in a chip using the fuse to be regenerated. That is, location information of cells to be repaired is generated by performing a fuse blowing process of cutting a specific one of the fuses using a laser.

Meanwhile, a method of forming a polycrystalline polysilicon film is conventionally used as a method for forming the fuse, but then, a method of forming a stacked structure of a TiN film and a polysilicon film is applied to secure a refresh margin. Was done.

Hereinafter, a fuse box of a semiconductor device including a metal fuse having a laminated structure of a conventional TiN film and a polysilicon film will be described with reference to FIG. 1.

Referring to FIG. 1, a conventional fuse box includes a first interlayer insulating layer 12 formed on a semiconductor substrate 11 fuse region, a fuse 15 formed on the first interlayer insulating layer 12, and the fuse 15. The fuse 15 and the second interlayer insulating film 16 and the second interlayer insulating film 16 and the first interlayer insulating film 12 formed on the first interlayer insulating film 12 to cover the fuse 15. A contact plug 17 formed to be in contact with each other and a metal wiring 18 formed to contact the contact plug 17 on the second interlayer insulating layer 16 are formed.

Here, the fuse 15 is formed of a laminated film of the TiN film 13 and the polysilicon film 14.

Then, although not shown, a repair process including a fuse blowing process and a reliability evaluation for cutting a specific fuse using a laser is performed.

Here, the TiN film and the polysilicon film of the fuse blown during the blowing process are exposed to the air. In the subsequent reliability evaluation performed after the repair process, moisture penetrates through the cut place and the TiN film of the blown fuse is oxidized and resisted. This increases.

However, in the above-described prior art, the volume of the oxidized TiN film expands, and as shown in FIG. 2, cracks are formed in which gaps are formed at the interface between the first and second interlayer insulating films. As a result, the TiN film of the adjacent non-blowed fuses is oxidized to cause a failing misrecognition as if blown.

Accordingly, an object of the present invention is to provide a fuse box of a semiconductor device and a method of forming the same, which are devised to solve the conventional problems as described above, which can prevent a failure of an adjacent fuse due to a crack.

The fuse box of the semiconductor device of the present invention for achieving the above object, the lower substrate is formed, the semiconductor substrate formed with a first interlayer insulating film to cover the lower structure; A second interlayer insulating film formed on the first interlayer insulating film; A fuse formed on the second interlayer insulating film in a stacked film structure of a TiN film and a polysilicon film; A third interlayer insulating film formed on the second interlayer insulating film including the fuse; A contact plug formed in the third and second interlayer insulating films and having a width greater than that of the fuse and penetrating the fuse; And a metal wire formed on the third interlayer insulating film to be connected to the contact plug.

The semiconductor device may further include a bit line formed on the portion of the first interlayer insulating layer under the contact plug to prevent the contact plug from reaching the semiconductor substrate active region.

In addition, the fuse box forming method of the semiconductor device of the present invention for achieving the above object comprises the steps of: forming a first interlayer insulating film on a semiconductor substrate formed with a lower structure; Forming a second interlayer insulating film on the first interlayer insulating film; Forming a fuse having a stacked structure of a TiN film and a polysilicon film on the second interlayer insulating film; Forming a third interlayer insulating film on the second interlayer insulating film including the fuse; Forming a contact plug in the third and second interlayer insulating films and having a width greater than that of the fuse and penetrating the fuse; And forming a metal wire connected to the contact plug on the third interlayer insulating film.

Wherein before forming the second interlayer insulating film, forming a bit line on the portion of the first interlayer insulating film under the contact plug to prevent the contact plug from reaching a semiconductor substrate active region. It is characterized by including.

(Example)

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

First, the technical principle of the present invention will be briefly described. In the present invention, a metal fuse made of a laminated film of a TiN film and a polysilicon film is formed on an interlayer insulating film of a semiconductor substrate. Form a contact plug.

In this case, since the contact plug is formed to surround the metal fuse in the width direction, even if a crack occurs due to the blowing process and the reliability evaluation, the oxidation of the TiN film due to the crack may be prevented from proceeding to an adjacent non-blowing fuse. Therefore, it is possible to prevent the failure of the adjacent fuse caused by the crack.

In detail, the fuse box of the semiconductor device according to the embodiment of the present invention will be described with reference to FIGS. 3A to 3B.

Referring to FIG. 3A, a fuse box of a semiconductor device according to the present invention includes a semiconductor substrate 31 having a lower structure (not shown) and a first interlayer insulating layer 32 formed to cover the lower structure. A second interlayer insulating film 34 formed on the first interlayer insulating film 32, a fuse 37 formed of a laminated film structure of the TiN film 35 and the polysilicon film 36 on the second interlayer insulating film 34, The third interlayer insulating film 38 formed on the second interlayer insulating film 34 including the fuse 37 and the third and second interlayer insulating films 38 and 34 are formed, and the width of the fuse 37 is greater than the width of the fuse 37. The contact plug 39 has a large width and is formed to penetrate the fuse 37, and a metal wiring 40 formed on the third interlayer insulating film 38 to be connected to the contact plug 39.

FIG. 3B is a cross-sectional view along the width direction of the fuse box shown in FIG. 3A, and as shown, a contact plug 39 having a width larger than that of the fuse 37 wraps the fuse 37 in the width direction. Is formed.

In this case, a bit line 33 is formed on the portion of the first interlayer insulating layer 34 under the contact plug 39 to prevent the contact plug 39 from reaching the active region of the semiconductor substrate 32.

Thereafter, a repair process including a fuse blowing process of cutting the fuse using a laser and a subsequent reliability evaluation are performed.

Here, the present invention is formed by the contact plug 39 having a larger width than the fuse 37 to surround the fuse 37, as shown in Figure 3a, TiN oxidized due to the moisture infiltrated during reliability evaluation Even if the film 35a is formed to cause cracks, the cracks do not proceed to the adjacent fuses, thereby preventing the adjacent fuses from failing.

Hereinafter, a method of forming a fuse box of a semiconductor device according to an exemplary embodiment of the present invention will be described in more detail with reference to FIGS. 4A to 4F.

Referring to FIG. 4A, a first interlayer insulating layer 32 is formed on the semiconductor substrate 31 on which a predetermined lower structure (not shown) is formed to cover the lower structures. Next, a bit line 33 is formed on the first interlayer insulating film 32. Here, the bit line 33 is formed to prevent the contact plug to be subsequently formed from reaching the active region of the semiconductor substrate 31.

Referring to FIG. 4B, a second interlayer insulating layer 34 is formed on the first interlayer insulating layer 32 on which the bit line 33 is formed to cover the bit line 33.

Referring to FIG. 4C, after the TiN film 35 and the polysilicon film 36 are sequentially deposited on the second interlayer insulating film 34, the polysilicon film 36 and the TiN film 35 are patterned. A fuse 37 having a laminated film structure of the polysilicon film 36 and the TiN film 35 is formed.

Referring to FIG. 4D, a third interlayer insulating film 38 is formed on the second interlayer insulating film 34 including the fuse 37 to cover the fuse 37.

Referring to Figure 4e, to form a contact hole (H) having a third and a second width larger than the inter-layer insulating film (38,34) and said fuse (37) to open the expression SIR fuse (37). Subsequently, a metal film is deposited to fill the contact hole H, and then CMP is formed to form a contact plug 39 penetrating the fuse 37.

Referring to FIG. 4F, after depositing a metal film on the third interlayer insulating film 38, the metal film is etched to form a metal wiring 40 connected to the contact plug 39.

Thereafter, a repair process including a fuse blowing process of cutting the fuse using a laser and a subsequent reliability evaluation are performed.

FIG. 5 is a short-live view of a semiconductor device showing the results of the blowing process and the reliability evaluation. As illustrated, the TiN film 35a oxidized by penetration of moisture through the cutout of the blown fuse during the reliability evaluation. ) Is formed.

Here, in the present invention, even if a crack occurs due to the oxidized TiN film 35a, the contact plug 39 formed to surround the fuse 37 in the width direction prevents the crack from proceeding to an adjacent fuse not blown. Since the adjacent fuse is blown, it is possible to prevent a falsely recognized mistake.

As mentioned above, although the present invention has been illustrated and described with reference to specific embodiments, the present invention is not limited thereto, and the following claims are not limited to the scope of the present invention without departing from the spirit and scope of the present invention. It can be easily understood by those skilled in the art that can be modified and modified.

As described above, according to the present invention, by forming the contact plug to have a larger width than the fuse, it is possible to prevent the crack generated during the blowing process and the reliability evaluation from proceeding to the non-blowing adjacent fuse.

Therefore, the present invention can prevent the failing of the adjacent fuse caused by the crack.

Claims (4)

A semiconductor substrate having a lower structure formed thereon and having a first interlayer dielectric layer formed to cover the lower structure; A second interlayer insulating film formed on the first interlayer insulating film; A fuse formed on the second interlayer insulating film in a stacked film structure of a TiN film and a polysilicon film; A third interlayer insulating film formed on the second interlayer insulating film including the fuse; A contact plug formed in the third and second interlayer insulating films and having a width greater than that of the fuse and penetrating the fuse; And A metal wiring formed on the third interlayer insulating film to be connected to the contact plug; A fuse box of a semiconductor device comprising a. The method of claim 1, And a bit line formed on the portion of the first interlayer insulating layer under the contact plug to prevent the contact plug from reaching the active region of the semiconductor substrate. Forming a first interlayer insulating film on a semiconductor substrate on which a lower structure is formed; Forming a second interlayer insulating film on the first interlayer insulating film; Forming a fuse having a stacked structure of a TiN film and a polysilicon film on the second interlayer insulating film; Forming a third interlayer insulating film on the second interlayer insulating film including the fuse; Forming a contact plug in the third and second interlayer insulating films and having a width greater than that of the fuse and penetrating the fuse; And Forming a metal wiring connected to the contact plug on the third interlayer insulating film; A fuse box forming method of a semiconductor device comprising a. The method of claim 3, wherein Before forming the second interlayer insulating film, forming a bit line on the portion of the first interlayer insulating film under the contact plug to function to prevent the contact plug from reaching a semiconductor substrate active region; A method for forming a fuse box of a semiconductor device, characterized in that.

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