KR100570067B1 - Semiconductor memory device and method for fabricating the same - Google Patents

Abstract

The present invention is to provide a semiconductor memory device that can reduce the occurrence of cracks even if the stress is applied to the fuse box in the process of the package, etc. To this end, the present invention is a semiconductor that can be repaired by blowing a fuse by irradiating with a laser In a memory device, a semiconductor memory device having a fuse in which a region other than a region to be irradiated with a laser is curved is provided. In another aspect, the present invention comprises the steps of forming an insulating film on the substrate is completed a predetermined process; Forming a capacitor forming hole by selectively removing the first insulating layer, and at least one fuse hole having the same shape as the capacitor forming hole in a region other than a region where a laser is to be irradiated during a repair process in a region where a fuse is to be formed; Forming more than; And forming a capacitor electrode film on an inner surface of the capacitor forming hole, and forming a fuse in an area in which a fuse including an inner surface of the hole for the fuse is to be formed using the capacitor electrode film. Provide a method.

Semiconductor, Memory, Repair, Fuse, Fuse Box.

Description

Semiconductor memory device and manufacturing method therefor {SEMICONDUCTOR MEMORY DEVICE AND METHOD FOR FABRICATING THE SAME}             

1 is a cross-sectional view of a conventional semiconductor memory device.

2A and 2B are cross-sectional views of a fuse box manufacturing process of a semiconductor memory device according to the prior art;

3 is a plan view of a fuse box of a semiconductor memory device manufactured as shown in FIGS. 2A and 2B.

4 to 6 are electron micrographs showing a problem in the fuse box of the semiconductor memory device manufactured by the prior art.

7 is a plan view showing a fuse box of a semiconductor memory device according to a preferred embodiment of the present invention.

8A and 8B are cross-sectional views of a fuse box manufacturing process of the semiconductor memory device shown in FIG.

9 and 10 are electron micrographs showing the fuse box of the semiconductor memory device manufactured according to the present embodiment.

Explanation of symbols on the main parts of the drawings

30: substrate

31: interlayer insulating film

32,33: fuse

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor memory device, and more particularly, to a fuse box and a method of manufacturing the same, which are laser irradiated in a repair process.

In the manufacture of a semiconductor memory device, in particular, a memory device, if any one of the many fine cells is defective, the memory device may not function as a memory and thus may be treated as a defective product. However, despite the fact that only a few cells in the memory have failed, discarding the entire device as defective is an inefficient process in terms of yield.

Therefore, the yield improvement is achieved by replacing the defective cell by using a spare cell (also referred to as a redundancy cell) previously installed in the memory device.

In the repair operation using redundancy cells, spare memory arrays and spare column arrays are pre-installed for each cell array so that defective memory cells having defects are stored in row / column units. This is done by releasing the cell.

In detail, when a defective memory cell is selected through a test after completion in a wafer state, a program is performed in an internal circuit to change an address corresponding to the address signal of a spare cell. Therefore, in actual use, when an address signal corresponding to a defective line is input, the selection is changed to a spare cell instead of the defective cell.

Among the above-described program methods, the most widely used method is to burn a fuse with a laser beam and blow it. The wiring broken by the laser irradiation is called a fuse, and the broken portion and the area surrounding the fuse box are called fuse boxes. .

1 is a cross-sectional view showing a conventional semiconductor memory device, with a left side showing a cross section of a cell region and a right side showing a fuse region.

As shown in FIG. 1, a cell region of a semiconductor memory device may include a device isolation layer 11, an active region 13, a gate pattern 14, and first and second storage node contact plugs 15a on a substrate 10. 17, the bit line contact plug 15b, the bit line 16, the storage node contact plug 19 forming the capacitor and the interlayer insulating films 12, 17, and 22, the dielectric thin film 20, and the plate electrode 23 24). The plate electrodes 23 and 24 are composed of a polysilicon film 23 and a TiN film 24.

The fuse region of the semiconductor memory device is a fuse composed of interlayer insulating films 11 ', 17' and 22 ', a polysilicon film 23' and a TiN film 24 'on a substrate, and an interlayer insulating film formed on the fuse. (25) is provided. In addition, reference numeral 26 denotes a fuse box formed by removing the interlayer insulating film 21 on the upper portion of the fuse by a predetermined thickness for cutting the fuse by laser irradiation during the repair process. The interlayer insulating films 11 ', 17', and 22 'are not formed separately, but are formed together when the interlayer insulating films 11, 17, and 22 are formed in the cell region.

As described above, the fuse is used to repair a portion where a defect occurs when a failure of the semiconductor memory device occurs.

In general, the fuse is not formed separately by an additional process, but is formed by using a conductive layer such as a bit line or a word line in the cell region.

In particular, in recent years, as the degree of integration of semiconductor memory devices increases, the height of structures of semiconductor memory devices also increases. As a result, when fuses are formed by using word lines or bit lines, which are relatively substructures, interlayers are formed to form fuse boxes. The difficulty of removing the insulating film has arisen. Therefore, in recent years, a conductive layer formed at a high position of a semiconductor memory device is used as a fuse line, and a conductive film for electrodes of metal wiring or capacitor is used as a fuse line.

The fuses 23 'and 24' shown in Fig. 1 are formed using a conductive film forming the plate electrodes 23 and 24 of the capacitor formed in the cell region.

2A and 2B are cross-sectional views of a fuse box manufacturing process of a conventional semiconductor memory device.

Referring to FIG. 2A, a conventional memory device forms an interlayer insulating layer 22 on a substrate 10 on which a predetermined process is completed.

Subsequently, a fuse 23 is formed in the region where the fuse is to be formed on the interlayer insulating film 22.

The fuse to be formed at this time is not formed as a separate conductive layer, but is formed by selecting one of the conductive layers formed in the cell region or the peripheral region. Here, the electrode film is formed of a capacitor.

Subsequently, as shown in FIG. 2B, an insulating film 25 is formed on the upper portion of the fuse, and the insulating film 25 is selectively removed with only a predetermined thickness remaining on the fuse to form a fuse box.

FIG. 3 is a plan view of a fuse box of the semiconductor memory device manufactured as shown in FIGS. 2A and 2B.

As shown in FIG. 3, a plurality of fuses are disposed in the fuse box. As described with reference to FIGS. 2A and 2B, a plurality of fuses are formed in the fuse box.

A fuse guard ring is disposed around the fuse to prevent foreign substances such as moisture from penetrating into the semiconductor device.

4 to 6 are electron micrographs showing a problem in the fuse box of the semiconductor memory device manufactured by the prior art.

4 to 6 looks at the problem in the fuse box according to the prior art.

As described above, the fuse box region selectively removes more insulating films than other layers to irradiate a laser during the repair process. Therefore, the fuse box region is relatively weaker in external stress than other regions of the semiconductor device.

In the repair process, the fuse is selectively blown to repair the spot where the defect is found, and then the semiconductor chip is packaged. In the process of packaging, the fuse guard ring surrounding the periphery of the fuse box is cracked by external force. do.

In particular, the area at the corner of the fuse box is particularly susceptible to external stresses, so that a slight impact of the package will cause cracks.

Referring to the electron micrographs of FIGS. 3 to 5, it can be seen that cracks are generated at edges of both ends of the fuse box due to the splice applied from the outside in the packaging process.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide a semiconductor memory device capable of reducing the occurrence of cracks even when a stress is applied to a fuse box in a package or the like process.

SUMMARY OF THE INVENTION The present invention provides a semiconductor memory device that can be repaired by irradiating with a laser to blow a fuse, wherein the semiconductor memory device includes a fuse in which a region other than the region to which the laser is irradiated is curved.

In another aspect, the present invention comprises the steps of forming an insulating film on the substrate is completed a predetermined process; Forming a capacitor forming hole by selectively removing the first insulating layer, and at least one fuse hole having the same shape as the capacitor forming hole in a region other than a region where a laser is to be irradiated during a repair process in a region where a fuse is to be formed; Forming more than; And forming a capacitor electrode film on an inner surface of the capacitor forming hole, and forming a fuse in an area in which a fuse including an inner surface of the hole for the fuse is to be formed using the capacitor electrode film. Provide a method.

Hereinafter, the most preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the technical idea of the present invention. do.

7 is a plan view illustrating a fuse box of a semiconductor memory device according to an exemplary embodiment of the present invention.

As shown in FIG. 7, in the memory device according to the present exemplary embodiment, the fuse disposed in the fuse box is not a conductive layer formed on the same plane, and both ends of the fuse have a bend.

At this time, the bending of both ends of the fuse is not a separate process. When the capacitor is formed in the cell region, the bending of the electrode film of the capacitor is performed in the fuse box.

At this time, the curved area is formed on both side portions of the fuse, except for the area to be irradiated by the laser is formed to be curved.

As semiconductor memory devices are highly integrated, in order to increase capacitance in a limited area, a lower electrode of a capacitor is formed in three dimensions such as a cylinder type, a stack type, and a concave type in a memory device.

In order to form the lower electrode in three dimensions, an insulating film is selectively removed to form a capacitor hole, an electrode film of a capacitor is formed inside the hole, and a dielectric thin film and an upper electrode are formed thereon. Holes are also formed in the box, and a conductive film is formed inside the holes.

Thus, both ends of the fuse are curved, thereby dispersing when stress is applied to the fuse box area in a packaging process or another process, thereby reducing the crack phenomenon occurring in the fuse box.

8A and 8B are cross-sectional views of a fuse box manufacturing process of the semiconductor memory device shown in FIG.

Referring to FIG. 8A, an insulating film 31 is formed on the substrate 30 on which a predetermined process is completed.

At this time, the insulating film 31 may include an undoped-silicate glass (USG) film, a phospho-silicate glass (PSG) film, a boro-silicate glass (BSG) film, a boro-phospho-silicate glass (BPSG) film, and a high density (HDP) film. Plasma oxide film, SOG (Spin On Glass) film, TEOS (Tetra Ethyl Ortho Silicate) film or HDP (high densigy plasma) oxide film, etc. Film formed by oxidizing a silicon substrate).

Subsequently, in order to manufacture a capacitor having a three-dimensional lower electrode, the insulating film in the region where the capacitor is to be formed is selectively removed to form a plurality of capacitor forming holes.

At this time, in the region where the fuse is to be formed, the hole for the fuse having the same shape as the above-described capacitor forming hole is formed in the region other than the region where the laser is to be irradiated in a subsequent process.

Subsequently, a conductive film for the lower electrode is formed along the step of the capacitor forming hole, and a dielectric thin film is formed thereon.

Subsequently, a conductive film for the upper electrode is formed on the dielectric thin film. At this time, the fuse 32 is formed as the conductive film for the upper electrode along the step of the fuse hole formed in the region where the fuse is to be formed.

The conductive film for the upper electrode may be formed of a conductive polysilicon film, and is formed using a metal film used as the electrode film of the capacitor. In addition, the process proceeds only to the region where the capacitor is to be formed, such as the MPS process required to manufacture the capacitor.

Subsequently, as shown in FIG. 8B, an insulating film 33 is formed on the entire surface of the substrate, an insulating film 33 having a predetermined thickness is left on the fuse, and the remaining insulating film 33 is selectively removed to form a fuse box. At this time, the insulating film remaining on the upper portion of the fuse is left to 3000 Å.

At this time, the insulating film 33 includes an undoped-silicate glass (USG) film, a phospho-silicate glass (PSG) film, a boro-silicate glass (BSG) film, a boro-phospho-silicate glass (BPSG) film, and a high density (HDP) film. Plasma oxide film, SOG (Spin On Glass) film, TEOS (Tetra Ethyl Ortho Silicate) film or HDP (high densigy plasma) oxide film, etc. Film formed by oxidizing a silicon substrate).

Looking at the shape of the fuse finally manufactured in the fuse box, since the capacitor forming hole is formed only in the region other than the region to be irradiated with the laser in the subsequent repair process, the fuse of the portion to be irradiated with the laser is formed in one plane during the repair process. On both sides of the fuse, i.e., the portion where the laser is not irradiated during the repair process, the fuse is formed with bending.

When both sides of the fuse are manufactured to bend in this way, the bent portion acts as a buffer layer by external force or stress in the subsequent packaging process, thereby greatly reducing the risk of cracking at the edge of the fuse box.

9 and 10 are electron micrographs showing the fuse box of the semiconductor memory device manufactured according to the present embodiment.

9 and 10, it can be seen that cracks do not occur in stress generated in the packaging process by forming a bend at both ends of the fuse.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

Here, the fuse is formed by using the upper electrode of the capacitor, and the bend is formed on both sides of the fuse, but it may be formed by using the capacitor lower electrode.

In the case where the fuse is formed of a conductive layer instead of the electrode film of the capacitor, the stress applied to the fuse box can be alleviated by deliberately forming a bend on both sides of the fuse.

According to the present invention, by bending both sides of the fuse in the memory device, it is possible to reduce the crack phenomenon caused by the stress applied to the fuse box in the package process or the module process.

In addition, since the present invention allows a part of the process of forming a capacitor in the cell region to be applied to the fuse region, a separate process step is not added, and thus cracks in the fuse box can be greatly reduced without additional process cost.

Claims (9)

In a semiconductor memory device that can be repaired by blowing a fuse by irradiating with a laser, A semiconductor memory device comprising a fuse in which a region other than a region to which a laser is irradiated is curved. The method of claim 1, And the shape of the bend to be formed on both sides of the fuse, which is the region to which the laser is to be irradiated, is the same as that of the capacitor electrode film in the cell region. The method of claim 2, And the fuse is disposed as a conductive film for a capacitor lower electrode in the cell region. The method of claim 2, And the fuse is disposed as a conductive film for a capacitor upper electrode in the cell region. Forming an insulating film on the substrate on which the predetermined process is completed; Forming a capacitor forming hole by selectively removing the first insulating layer, and at least one fuse hole having the same shape as the capacitor forming hole in a region other than a region where a laser is to be irradiated during a repair process in a region where a fuse is to be formed; Forming more than; And Forming a capacitor electrode film on an inner surface of the capacitor forming hole, and forming a fuse in a region where a fuse including an inner surface of the hole for the fuse is to be formed using the capacitor electrode film; Method of manufacturing a semiconductor memory device comprising a. The method of claim 5, wherein Forming a second insulating film on the fuse; And And selectively removing the second insulating film on the fuse, leaving only a predetermined thickness to form a fuse box. The method of claim 6, And forming a second insulating film of about 3000 Å on the fuse in the forming of the fuse box. The method of claim 5, wherein And the capacitor electrode film is a conductive film for the lower electrode of the capacitor. The method of claim 8, And the capacitor electrode film is a conductive film for the upper electrode of the capacitor.

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