JP2008288417A - Fuse element structure and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuse element having a copper wiring which can be coincidentally formed with a copper wiring used in an internal circuit of a semiconductor device and capable of cutting the fuse without giving damages to a semiconductor substrate, and further capable of sufficiently narrowing an interval between wirings for fuse and arranging it within a small area. <P>SOLUTION: Each fuse wiring 1a, 1b, 1c, 1d comprises: fuse wirings 201, 202, 203, 204 for cutting cut by an irradiation of a laser beam of an infrared wavelength region; and copper wirings 205, 206, 207, 208. The fuse wiring for cutting and the copper wiring are connected and have a laser reflection region 2 positioning on the copper wiring which does not overlap to the fuse wiring for cutting in planar view, and a cutting wiring region 3 positioning on the fuse wiring for cutting which does not overlap to the copper wiring in planar view. The fuse element structure 10 is as follows: the laser reflection region 2 of the adjacent fuse wirings 1b, 1d are arranged to the both sides of the cutting wiring region 3 in a central fuse wiring 1c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuse element structure and a semiconductor device, and in particular, includes a copper wiring that can be formed simultaneously with a copper wiring used for an internal circuit of a semiconductor device, and can cut a fuse without damaging a semiconductor substrate. Moreover, the present invention relates to a fuse element structure that can be arranged in a small area and a semiconductor device including the fuse element structure.

  Conventionally, in a semiconductor device such as a DRAM (Dynamic Random Access Memory) or a device having a memory cell such as a flash memory, a spare memory cell that operates normally when a memory cell having a problem in circuit operation occurs in a manufacturing process. Replacement with (redundant cells) is generally performed. As a typical method for replacing a memory cell, a fuse wiring which is normally in a conductive state is heated and cut by irradiating a laser beam to operate a circuit (redundant circuit) having a specific function for replacement. There is.

As the fuse wiring, a wiring mainly composed of aluminum (Al) located above the device (hereinafter referred to as “aluminum wiring”) is often used. Further, as a laser beam for cutting, a laser beam in an infrared wavelength region having a wavelength of about 1 μm is often used.
The aluminum film has a high reflectance with respect to a laser beam in the infrared wavelength region. Therefore, the wiring composed of a single aluminum film is difficult to cut with a laser beam in the infrared wavelength region. Therefore, in general, when aluminum is used as a fuse wiring of a semiconductor device, titanium nitride (TiN) or titanium (Ti) is formed on the surface of the aluminum film in order to facilitate cutting with a laser beam in the infrared wavelength region. Etc. are provided.

  In addition, in conventional memory devices, aluminum wiring is generally used. However, in recent years, from the viewpoint of miniaturization and speeding up of devices, instead of aluminum wiring, copper wiring mainly composed of copper (Cu) is used. It is being considered for use. Copper wiring is already widely used in logic products and the like. Since it is difficult to form the copper wiring using dry etching, the copper wiring is generally formed using a technique (damascene method) of filling the groove with copper.

  FIG. 12 is a cross-sectional view of a copper wiring formed using the damascene method. As shown in FIG. 12, a barrier metal 103 is formed along the side surface and bottom surface of the wiring groove 102 formed in the interlayer insulating film 101, and the inside of the wiring groove 102 in which the barrier metal 103 is formed is embedded in the side surface and bottom surface. Thus, the copper wiring 104 is formed. Further, as shown in FIG. 12, the copper wiring 104 formed by the damascene method is such that the side surface and the bottom surface are covered with the barrier metal 103 and the copper film is exposed on the top surface.

  The copper wiring 104 shown in FIG. 12 is formed by the method shown below, for example. First, the interlayer insulating film 101 formed on a semiconductor substrate (not shown) is patterned using a photolithography film to form a wiring groove 102. Next, a metal film made of tantalum (Ta) or the like serving as a barrier metal 103 for suppressing a reaction between the interlayer insulating film 101 and the copper wiring 104 is formed on the interlayer insulating film 101 and the wiring trench 102. As a result, a metal film is formed along the side surface and the bottom surface of the wiring groove 102. Thereafter, a copper (Cu) film to be the copper wiring 104 is formed on the metal film, and the copper film and the metal film on the surface of the interlayer insulating film 101 are removed by using a CMP (Chemical Mechanical Polishing) method. As a result, the copper wiring 104 is formed so as to fill the inside of the wiring groove 102 in which the barrier metal 103 is formed on the side surface and the bottom surface.

  In a semiconductor device using such a copper wiring, the following problems occur when the fuse wiring is formed of the copper wiring. That is, since copper is a material having high reflectivity with respect to the laser beam in the infrared wavelength region normally used for cutting the fuse wiring, if the upper surface of the fuse wiring is formed of copper, the fuse wiring Heating was not successful and the fuse wiring could not be cut easily.

As a proposal to solve this problem, there is a method of performing special processing on the copper wiring (for example, see Patent Document 1). Patent Document 1 proposes a technique of forming a light absorbing member having a high light absorption rate for a laser beam on at least a side surface portion of a barrier metal that covers the side surface and the bottom surface of a copper wiring.
However, when the light absorbing member is formed around the barrier metal, there is a problem that the manufacturing process for forming the light absorbing member is newly increased, so that the process becomes complicated. In general, since the wiring used as the fuse wiring is also used as the wiring used in other internal circuits constituting the semiconductor device, the connection method with the wiring existing below the fuse wiring is also effective. There is a problem that the influence of forming the absorbing member is exerted. In addition, since it is necessary to heat the copper wiring from the side surface, there is also a problem that the laser beam irradiation method needs to be changed.

As another method for facilitating cutting of the fuse wiring when the fuse wiring is formed of copper wiring, a method of laminating a member made of a material having a large light absorption rate with respect to a laser beam on the upper layer of the copper wiring is also available. Conceivable. However, in consideration of performing polishing by CMP when forming a copper wiring using the damascene method, the manufacturing process for providing a member made of a material having a large light absorption rate on the surface portion of the copper wiring is considerably complicated. It will become something.
As described above, the method of adding a member having a high light absorption rate to the copper wiring has a problem in terms of cost because the manufacturing process increases or the manufacturing process needs to be significantly changed.

  As another method for facilitating the cutting of the fuse wiring when the fuse wiring is formed of a copper wiring, a method of setting the wavelength range of the laser beam to a visible wavelength range of 0.8 μm or less can be considered. When a laser beam in the visible wavelength region is used as the laser beam, the optical absorptance with respect to copper increases, so that the copper wiring can be directly heated and cut. However, if the laser beam is changed from the infrared wavelength region to the visible wavelength region, the light absorption rate with respect to the silicon substrate also increases. For this reason, when the laser beam reaches the silicon substrate when the fuse wiring is cut, the silicon substrate is damaged.

  In order to solve the problem that the laser beam reaches the silicon substrate when cutting the fuse wiring, the width of the fuse wiring is increased to the same as the spot diameter of the laser beam, and the laser beam is below the fuse wiring. It is possible to prevent this from reaching. In general, the laser beam irradiated when the fuse wiring is cut can be narrowed down to a spot diameter of about 2 μm in diameter. However, when it is necessary to arrange a large number of fuse wirings as in a memory device, if the width of the fuse wiring is expanded to the same extent as the spot diameter of the laser beam, the area required to arrange the fuse wiring becomes large. It becomes too much and is not practical. Therefore, it has been difficult to use a laser beam in the visible wavelength region as a laser beam.

A problem in the case of cutting a fuse wiring using an aluminum wiring by using a laser beam in an infrared wavelength region will be described with reference to the drawings.
FIG. 13 is a plan view showing an example of a conventional fuse wiring. As shown in FIG. 13, the three aluminum wirings 105, 106, 107 constituting the fuse wiring are arranged in parallel. The intervals S1 between adjacent aluminum wirings are all equal.

For example, when only the aluminum wiring 106 arranged at the center in FIG. 13 is cut, a laser beam spot 108 is irradiated only on the central aluminum wiring 106. It is difficult to reduce the spot diameter of the laser beam to about 2 μm or less. Further, the laser beam may be misaligned during alignment. For this reason, when arranging the aluminum wirings 105, 106, 107, the distance S1 between the aluminum wirings is made sufficiently long in consideration of the spot diameter of the laser beam and the misalignment of the laser beam alignment, It was necessary to prevent erroneous cutting of the aluminum wirings 105 and 107 adjacent to the aluminum wiring 106.
Therefore, the fuse wiring shown in FIG. 13 requires a large area as a fuse arrangement region, and it is required to reduce the area of the fuse arrangement region. In particular, in the case where a large number of fuse wirings are arranged, it becomes a hindrance to the reduction of the semiconductor chip size, which is a problem.

As a method of narrowing the interval between fuse wirings, a technique of providing a protective layer on a part of the fuse wiring has been proposed (see, for example, Patent Document 2). Here, fuse wiring in which a protective layer is provided on a part of the fuse wiring will be described with reference to the drawings.
FIG. 14 is a drawing showing an example of a fuse element structure having a fuse wiring in which a protective layer is provided on a part of the fuse wiring. FIG. 14 (a) is a plan view, and FIG. FIG. 14B is a cross-sectional view taken along the line AA ′ in FIG.

  In the fuse element structure shown in FIG. 14, as shown in FIG. 14B, three fuse wirings 120 made of aluminum wiring are formed on an interlayer insulating film 124 provided on a semiconductor substrate (not shown). 121 and 122 are arranged in parallel. As shown in FIG. 14A, the intervals S2 between adjacent fuse wirings are all equal. Further, an interlayer insulating film 125 is formed on the fuse wirings 120, 121, and 122, and the laser beam is reflected on the interlayer insulating film 125 as shown in FIGS. 14 (a) and 14 (b). Protective layers 120a, 121a, and 122a are formed so as to cover a part of each of the fuse wirings 120, 121, and 122. As shown in FIG. 14A, the protective layer 121 a disposed on the fuse wiring 121 disposed in the center is protected on the fuse wirings 120 and 122 disposed on both sides of the fuse wiring 121. The layers 120a and 122a and the fuse wiring are arranged at different positions in the length direction.

  For example, in the fuse element structure shown in FIG. 14, when the central fuse wiring 121 is cut, a laser beam spot is irradiated to a position indicated by reference numeral 123 in FIG. At this time, since the fuse wirings 120 and 122 that are not cut off on both sides of the central fuse wiring 121 are covered with the protective layers 120a and 122a, damage to the fuse wirings 120 and 122 by the laser beam is prevented. Cutting is prevented. Therefore, the distance S2 between the fuse wirings can be made smaller than the distance between the adjacent fuse wirings (for example, the distance S1 in FIG. 13) when the protective layer is not provided.

  15 is a cross-sectional view taken along the line A-A ′ of FIG. 14A after cutting the central fuse wiring 121 in the fuse element structure shown in FIG. As shown in FIG. 15, in the place where the cut central fuse wiring 121 was present, the material such as aluminum constituting the cut fuse wiring 121 was vaporized by heating with a laser beam and the volume thereof was increased. Therefore, the interlayer insulating film 125 disposed on the cut fuse wiring 121 is blown off, and the cavity 130 is formed. Further, as shown in FIG. 15, due to the impact when the cavity 130 is formed, toward the fuse wiring 120 adjacent to the fuse wiring 121 cut from the interlayer insulating film 125 in the vicinity of the cut fuse wiring 121. , Cracks 131 are formed. As shown in FIG. 15, when the crack 131 reaches the fuse wiring 120 that has not been cut, the fuse wiring 120 is damaged and the fuse wiring 120 is in a semi-cut state.

In the fuse element structure shown in FIGS. 14 and 15, in order to avoid the problem caused by the crack 131 that occurs when the fuse wiring 121 is cut, the interval S <b> 2 between the adjacent fuse wirings is sufficiently wide and cut. Even if the crack 131 occurs in the interlayer insulating film 125 near the fuse wiring 121, it is necessary to prevent the crack 131 from reaching the fuse wiring 120 adjacent to the cut fuse wiring 121.
As described above, when the protective layer is provided on a part of the fuse wiring, it is possible to prevent the laser beam from being directly irradiated to the uncut fuse wirings 120 and 122 on both sides of the cut fuse wiring 121. However, in order to avoid the problem caused by the crack 131 generated at the time of cutting, a sufficient interval S2 between the adjacent fuse wirings must be secured, and the interval between the fuse wirings is sufficiently narrowed. I couldn't.

Further, as a fuse wiring that is cut by a laser beam, a technique for obtaining a dense pitch fuse without damaging adjacent fuses when irradiating a laser beam to break the fuse is proposed (for example, see Patent Document 3). ing.
In addition to the above, the fuse wiring cut by the laser beam includes a technique for reducing damage to the insulating film under the fuse at the time of cutting (for example, see Patent Document 4), and the remaining of the interlayer insulating film on the fuse wiring. A technique (for example, see Patent Document 5) that facilitates film control has been proposed.
JP 2004-96064 A JP-A-11-74364 JP 2003-224187 A JP 2003-17572 A JP-A-10-261720

  However, the above-described conventional techniques each include a copper wiring that can be formed simultaneously with the copper wiring used for the internal circuit of the semiconductor device, and when the fuse can be cut without damaging the semiconductor substrate, The interval between the fuse wirings could not be sufficiently narrowed.

The present invention has been made in view of such circumstances, and includes a copper wiring that can be formed simultaneously with a copper wiring used for an internal circuit of a semiconductor device, and can cut a fuse without damaging the semiconductor substrate. In addition, it is an object of the present invention to provide a fuse element structure in which the interval between fuse wirings can be sufficiently narrowed and arranged in a small area.
It is another object of the present invention to provide a semiconductor device having a fuse element structure arranged in a small area.

The inventor has intensively studied in order to solve the above problems, and has completed the present invention. That is, the present invention relates to the following.
The fuse element structure of the present invention is a fuse element structure having at least three rows of fuse wirings, wherein each fuse wiring is cut by irradiating a laser beam in an infrared wavelength region, and the cutting fuse wiring A contact plug that penetrates the interlayer insulating film in an overlap region in which the cutting fuse wiring and the copper wiring overlap in a plan view. The cutting fuse wiring and the copper wiring are connected via a laser reflection region located on the copper wiring that does not overlap with the cutting fuse wiring in a plan view, and does not overlap with the copper wiring in a plan view. A cutting wiring region located on the cutting fuse wiring, and other fuses on both sides of the at least three rows of fuse wiring. The central fuse wire's wiring is arranged, wherein said laser reflective region of the fuse wire adjacent to both sides of the cutting line regions are arranged.

  In the fuse element structure of the present invention, the side surface and the bottom surface of the copper wiring may be covered with a barrier metal.

  In the fuse element structure of the present invention, an upper interlayer insulating film is provided on the copper wiring, and the upper interlayer insulating film includes a thin film region provided in a portion overlapping at least the region including the cut wiring region in a plan view. And a thick film region thicker than the thin film region, and a surface protective film may be provided on the thick film region.

  In the fuse element structure of the present invention, an overlap region may be disposed at both ends of the cut wiring region.

  A semiconductor device according to the present invention may include any of the fuse element structures described above.

  The semiconductor device of the present invention is a semiconductor device having the above-described fuse element structure on a semiconductor substrate, wherein one end of the cutting fuse wiring has a diffusion layer provided on the semiconductor substrate, An end of the copper wiring connected through a first connection plug that penetrates a lower interlayer insulating film provided on the diffusion layer and facing one end of the cutting fuse wiring in plan view, The diffusion layer may be connected to the lower interlayer insulating film and the second connection plug penetrating the interlayer insulating film.

  In the above semiconductor device, a connection portion of the first connection plug with the cutting fuse wiring may be cut by irradiating a laser beam in an infrared wavelength region.

  The fuse element structure of the present invention is a fuse element structure having at least three rows of fuse wirings, wherein each fuse wiring is cut by irradiating a laser beam in an infrared wavelength region, and the cutting fuse wiring A contact plug that penetrates the interlayer insulating film in an overlap region in which the cutting fuse wiring and the copper wiring overlap in a plan view. The cutting fuse wiring and the copper wiring are connected via a laser reflection region located on the copper wiring that does not overlap with the cutting fuse wiring in a plan view, and does not overlap with the copper wiring in a plan view. A cutting wiring region located on the cutting fuse wiring, and other fuses on both sides of the at least three rows of fuse wiring. The central fuse wire's wires are disposed, since the laser reflection area of the fuse interconnect adjacent to both sides of the cutting line regions are arranged, as shown below, it can be arranged in a small area.

  That is, in the fuse element structure of the present invention, the cutting fuse wiring that is cut when the cutting wiring area is irradiated with a laser beam in the infrared wavelength region in order to cut the cutting fuse wiring in the cutting wiring area of the central fuse wiring. Since the laser reflection area of the adjacent fuse wiring is arranged on both sides of the cutting wiring area of the central fuse wiring, the cutting of the laser reflection area does not overlap with the cutting fuse wiring in plan view. A sufficient distance is ensured between the cutting fuse wiring constituting the cutting wiring area of the central fuse wiring and the cutting fuse wiring of the other fuse wiring that is not cut.

  Therefore, in the fuse element structure of the present invention, even if the cutting fuse wiring is cut by irradiating the cutting wiring region of the central fuse wiring with the laser beam in the infrared wavelength region, other fuses arranged on both sides of the central fuse wiring The fuse wiring for cutting the wiring is not easily damaged, and erroneous disconnection of the other fuse wiring is prevented.

  Further, in the fuse element structure of the present invention, since the laser reflection areas of the adjacent fuse wiring are arranged on both sides of the cutting wiring area where the cutting fuse wiring to be cut is arranged, the cutting fuse wiring to be cut A laser reflecting region is arranged between the cutting fuse wiring located next to the cutting fuse wiring to be cut. Therefore, the cutting fuse wiring located next to the cutting fuse wiring to be cut is not the fuse wiring for cutting other fuse wirings arranged on both sides of the central fuse wiring, but is arranged next to the central fuse wiring. The fuse wiring for cutting the fuse wiring arranged at a position further away from the other fuse wiring. For this reason, the distance between the cutting fuse wiring to be cut and the cutting fuse wiring located adjacent thereto is sufficiently large. Therefore, even if the cutting fuse wiring for cutting the central fuse wiring is cut, the cutting fuse wiring located next to the cutting fuse wiring for the central fuse wiring is not easily damaged, and erroneous cutting is prevented.

  Further, in the fuse element structure of the present invention, since the laser reflection areas of the adjacent fuse wiring are arranged on both sides of the cutting wiring area where the cutting fuse wiring to be cut is arranged, the cutting fuse wiring to be cut A laser reflecting region is arranged between the cutting fuse wiring located next to the wiring. Therefore, the distance between the cutting fuse wiring to be cut and the cutting fuse wiring located adjacent thereto is sufficiently wide. Therefore, even if the cutting fuse wiring for cutting the central fuse wiring is cut, the cutting fuse wiring located next to the cutting fuse wiring for the central fuse wiring is not easily damaged, and erroneous cutting is prevented.

Further, in the fuse element structure of the present invention, by cutting the cutting fuse wiring in the cutting wiring area of the central fuse wiring, a crack was formed in the interlayer insulating film near the cutting fuse wiring of the cut central fuse wiring However, since there is a sufficient distance between the fuse wiring for cutting the cut central fuse wiring and the fuse wiring for cutting other fuse wiring that was not cut, cutting other fuse wiring that was not cut Cracks are unlikely to reach the fuse wiring.
As described above, in the fuse element structure of the present invention, it is possible to prevent erroneous disconnection of other fuse wirings, and it is difficult to cause problems due to cracks generated when the fuse wirings are disconnected. Can be arranged in a small area.

  In the fuse element structure of the present invention, the cutting fuse wiring is cut by irradiating the laser beam in the infrared wavelength region. For example, when the cutting fuse wiring is made of copper wiring Thus, there is no need to perform special processing on the copper wiring, and the copper wiring used for the internal circuit of the semiconductor device can be used as it is as the copper wiring constituting the fuse wiring. Therefore, the copper wiring constituting the fuse element structure of the present invention can be formed simultaneously with the copper wiring used for the internal circuit of the semiconductor device without increasing the manufacturing process or significantly changing the manufacturing process. It becomes.

  In the fuse element structure of the present invention, the fuse wiring for cutting is cut by irradiating the laser beam in the infrared wavelength region, so that the fuse wiring can be cut without damaging the semiconductor substrate. is there.

  Further, in the fuse element structure of the present invention, when the side and bottom surfaces of the copper wiring are covered with a barrier metal, copper diffusion due to the reaction between the interlayer insulating film and the copper wiring is suppressed, so that high quality It has a copper wiring.

  In the fuse element structure of the present invention, an upper interlayer insulating film is provided on the copper wiring, and the upper interlayer insulating film is provided in a portion overlapping at least a region including the cut wiring region in a plan view. And a thick film region thicker than the thin film region, and a surface protective film is provided on the thick film region, the thick upper interlayer insulating film and the surface protection It is possible to prevent an adverse effect caused by irradiating the thick film region provided with the film with a laser beam for cutting the cutting fuse wiring. In addition, since the surface protective film is not provided on the thin film region, the surface protective film does not hinder the cutting of the cutting fuse wiring in the cutting wiring region. Furthermore, since the thin film region is at least a portion overlapping the cut wiring region in plan view, the upper interlayer insulating film constituting the thin film region is unlikely to hinder the cutting of the fuse wiring for cutting the cut wiring region. It becomes.

  Further, in the fuse element structure of the present invention, when the overlap region is disposed at both ends of the cut wiring region, both sides and both ends of the cut wiring region of the central fuse wiring are viewed in plan view. It is in a state surrounded by copper wiring. For this reason, even if alignment misalignment occurs during laser beam irradiation, the cutting fuse wiring can be accurately cut in the cutting wiring region.

  In addition, since the semiconductor device according to the present invention includes the fuse element structure described above, the semiconductor device includes a fuse element structure arranged in a small area.

“First Embodiment”
A semiconductor device and a fuse element structure according to a first embodiment of the present invention will be described with reference to the drawings.
1 to 3 are enlarged views of an example of a semiconductor device of the present invention, and are diagrams for explaining a fuse element structure of the present invention provided in the semiconductor device of the present invention. is there. 1 is a plan view of the fuse element structure of the present invention, FIG. 2 is a cross-sectional view taken along line BB ′ of FIG. 1, and FIG. 3 is a cross-sectional view taken along line CC ′ of FIG. .

  In FIG. 1, reference numeral 10 indicates a fuse element structure. As shown in FIG. 1, the fuse element structure 10 has four rows of fuse wirings 1a, 1b, 1c, and 1d extending in the vertical direction in FIG. Each of the fuse wirings 1a, 1b, 1c, and 1d is provided with cutting fuse wirings 201, 202, 203, and 204 and copper wirings 205, 206, 207, and 208, as shown in FIGS. And arranged in parallel so that the interval S3 between adjacent fuse wirings is constant.

  In the present embodiment, the arrangement of the cutting fuse wirings 201, 202, 203, 204 and the copper wirings 205, 206, 207, 208 constituting the fuse wirings 1a, 1b, 1c, 1d is adjacent to the fuse wirings. Are arranged in the opposite direction. More specifically, the fuse wirings 201 and 203 for cutting the fuse wirings 1a and 1c are arranged above the copper wirings 205 and 207 in FIG. 1, and the fuse wirings 202 and 204 for cutting the fuse wirings 1b and 1d are shown in FIG. 1, the upper and lower arrangements in FIG. 1 are different for each fuse wiring arranged in parallel.

  The cutting fuse wirings 201, 202, 203, 204 are cut by irradiating a laser beam in the infrared wavelength region, and are made of a material selected from tungsten silicide (WSi), polysilicon, and titanium nitride (TiN). It consists of a single layer or a laminated film in which two or more layers are laminated.

  As shown in FIGS. 1 and 3, the copper wirings 205, 206, 207, and 208 have a wiring width wider than that of the cutting fuse wirings 201, 202, 203, and 204. Further, the copper wirings 205, 206, 207, 208 are formed using a damascene method, and as shown in FIGS. 2 and 3 (not shown in FIG. 1), the copper wirings 205, 206, 207 are formed. , 208 are covered with barrier metals 206a, 207a, 208a for suppressing diffusion of copper due to the reaction between the interlayer insulating film 216 and the upper interlayer insulating film 217 and the copper wirings 205, 206, 207, 208. ing. The barrier metals 206a, 207a, and 208a are made of a metal film such as tantalum (Ta).

  As shown in FIGS. 1 to 3, the cutting fuse wirings 201, 202, 203, and 204 are formed on a lower interlayer insulating film 215 made of a silicon oxide film or the like provided on a silicon substrate constituting the semiconductor device. Copper wirings 205, 206, 207, and 208 are provided above the cutting fuse wirings 201, 202, 203, and 204 via an interlayer insulating film 216 made of a silicon oxide film or the like.

  As shown in FIGS. 1 and 2, the fuse wirings 1a, 1b, 1c, and 1d have cutting fuse wirings 201, 202, 203, and 204 and copper wirings 205, 206, 207, and 208 in plan view. Overlapping areas are provided that overlap. A contact plug 209 that penetrates the interlayer insulating film 216 is provided in the overlap region. The contact plug 209 has an end near the direction in which the copper wirings 205, 206, 207, 208 extend in the overlap region in order to sufficiently reduce the installation area of the fuse wirings 1a, 1b, 1c, 1d. Is provided. The contact plug 209 is made of a conductive material such as tungsten (W) or phosphorous doped polysilicon. The cutting fuse wirings 201, 202, 203, and 204 and the copper wirings 205, 206, 207, and 208 constituting the fuse wirings 1a, 1b, 1c, and 1d are connected to each other through the contact plug 209. .

  The length L1 of the overlap region is set to be optimum according to the material, film thickness, etc. of the cutting fuse wirings 201, 202, 203, 204, the interlayer insulating film 216, and the upper interlayer insulating film 217. It is preferable that the distance L2 between 209 and the edge of the overlap region on the side of the cutting fuse wirings 201, 202, 203, 204 is in the range of 0.5 to 2.0 μm. If the distance L2 is less than 0.5 μm, it may not be possible to sufficiently prevent the impact of the impact at the time of cutting the fuse wirings 1a, 1b, 1c, and 1d from reaching the contact plug 209, which is not preferable. Further, if the distance L2 exceeds 2.0 μm, the installation area of the fuse wirings 1a, 1b, 1c, and 1d cannot be sufficiently reduced, which is not preferable.

An upper interlayer insulating film 217 made of a silicon oxide film or the like is provided on the copper wirings 205, 206, 207 and 208. In this embodiment, since the copper wirings 205, 206, 207, and 208 are formed using the damascene method, the upper interlayer insulating film 217 has the same thickness as the copper wirings 205, 206, 207, and 208. It has a two-layer structure (not shown) of a first interlayer insulating film and a second interlayer insulating film formed after copper wirings 205, 206, 207, 208 are embedded in the first interlayer insulating film.
In the present embodiment, as shown in FIGS. 1 to 3, the upper interlayer insulating film 217 includes a thin film region 220 provided in a region including a portion overlapping the region including the cut wiring region 3 in plan view, And a thick film region 220a having a thickness larger than that of the thin film region 220. The upper interlayer insulating film 217 constituting the thin film region 220 does not hinder the cutting of the cutting fuse wirings 201, 202, 203, 204 as long as the surfaces of the copper wirings 205, 206, 207, 208 are not exposed. It is formed so thin. Further, as shown in FIGS. 2 and 3, a surface protective film 218 made of silicon oxynitride (SiON), polyimide, or the like is provided on the thick film region 220a of the upper interlayer insulating film 217.

  Moreover, each fuse wiring 1a, 1b, 1c, 1d has a laser reflection area 2 and a cut wiring area 3 as shown in FIGS. The laser reflection region 2 is a region located on the copper wirings 205, 206, 207, and 208 that do not overlap the cutting fuse wirings 201, 202, 203, and 204 in plan view. The cut wiring region 3 is a region located on the cutting fuse wires 201, 202, 203, and 204 that do not overlap the copper wires 205, 206, 207, and 208 in plan view. Here, an overlap region (region indicated by L1 in FIGS. 1 and 2) where the copper wirings 205, 206, 207, 208 and the cutting fuse wirings 201, 202, 203, 204 overlap in plan view is an upper layer of copper. Since it is a wiring, it has a function of reflecting the laser beam, but it is not included in the laser reflection region 2 for the sake of clarity of explanation.

  In this embodiment, as shown in FIG. 1, in the central fuse wirings 1b and 1c in which other fuse wirings are arranged on both sides of the four rows of fuse wirings 1a, 1b, 1c and 1d, the cutting wiring Only the laser reflection region 2 of the fuse wiring adjacent to the both sides of the region 3 is disposed, and the cut wiring region 3 is not disposed. Therefore, as shown in FIG. 1 and FIG. 3, the distance between the cutting fuse wiring 201 constituting the cutting wiring area 3 of the fuse wiring 1a and the cutting fuse wiring 203 constituting the cutting wiring area 3 of the fuse wiring 1c The distance between the cutting fuse wiring 202 constituting the cutting wiring area 3 of the fuse wiring 1b and the cutting fuse wiring 204 constituting the cutting wiring area 3 of the fuse wiring 1d is sufficiently wide.

  Further, both ends of each of the fuse wirings 1a, 1b, 1c and 1d are connected to an internal circuit including a transistor of the semiconductor device, a power supply wiring, a ground potential (GND) wiring, and the like. The fuse wirings 1a, 1b, 1c, and 1d are in a conductive state in the initial state, and the fuse wirings 1a, 1b, 1c, and 1d are disconnected, so that a circuit having a specific function for replacement ( Redundant circuit) is activated.

The fuse element structure shown in FIGS. 1 to 3 can be manufactured as follows, for example.
First, the fuse wirings 201, 202, 203, and 204 for cutting are formed on the lower interlayer insulating film 215 provided on the silicon substrate constituting the semiconductor device by using a photolithography method and a dry etching method. Thereafter, an interlayer insulating film 216 is formed on the cutting fuse wirings 201, 202, 203, and 204, and the surface of the interlayer insulating film 216 is flattened using a CMP method.
Subsequently, a contact hole is opened by a known means in a region that becomes an overlapping region where the cutting fuse wirings 201, 202, 203, 204 and the copper wirings 205, 206, 207, 208 overlap in plan view. A contact plug 209 is formed by filling the inside with a conductive material.

Subsequently, a first interlayer insulating film having the same thickness as the copper wirings 205, 206, 207, and 208 is formed on the interlayer insulating film 216. Thereafter, a copper wiring is formed using a damascene method. That is, a trench is provided in the first interlayer insulating film, and copper wirings 205, 206, 207, 208 whose side surfaces and bottom surfaces are covered with barrier metals 206a, 207a, 208a are formed so as to be embedded in the first interlayer insulating film. . Subsequently, a second interlayer insulating film is formed on the copper wirings 205, 206, 207 and 208. Thus, the upper interlayer insulating film 217 having a two-layer structure (not shown) of the first interlayer insulating film and the second interlayer insulating film is formed.
Thereafter, a surface protective film 218 is formed on the upper interlayer insulating film 217, and after removing the surface protective film 218 in the thin film region 220 by using a photolithography method and a dry etching method, the upper interlayer insulating film is subsequently continued. The film 217 is removed as long as the surfaces of the copper wirings 205, 206, 207, 208 are not exposed. Thus, an upper interlayer insulating film 217 having a thin film region 220 and a thick film region 220a and a surface protective film 218 provided only on the thick film region 220a are formed.
Through the above steps, the fuse element structure shown in FIGS. 1 to 3 is obtained.

Next, the operation when the fuse wiring constituting the fuse element structure shown in FIGS. 1 to 3 is cut will be described with reference to FIGS.
FIG. 4 is a plan view for explaining an example of the spot position of the laser beam irradiated to cut the fuse wiring constituting the fuse element structure. FIG. 5 is a diagram for explaining a state after the fuse wiring is cut, and is a cross-sectional view taken along the line DD ′ in FIG. 4 (corresponding to the line BB ′ in FIG. 1). 6 is a view for explaining a state after the fuse wiring is cut, and is a cross-sectional view taken along the line EE ′ of FIG. 4 (corresponding to the line CC ′ of FIG. 1).

In the present embodiment, a case where the second fuse wiring 1c from the right in which other fuse wirings are arranged on both sides of the four rows of fuse wirings 1a, 1b, 1c, and 1d will be described as an example. .
In the present embodiment, as shown in FIG. 4, the fuse wiring 1c is cut by irradiating the cutting fuse wiring 203 constituting the cutting wiring area 3 of the fuse wiring 1c with a laser beam spot 230 in the infrared wavelength region. Is done. When the cutting fuse wiring 203 is irradiated with a laser beam in the infrared wavelength region, a material such as tungsten silicide (WSi) constituting the cutting fuse wiring 203 absorbs the laser beam and is heated and vaporized. As a result, the fuse wiring 1c is cut.

  At this time, in the vicinity of the cutting fuse wiring 203 irradiated with the laser beam, as shown in FIGS. 5 and 6, due to the volume expansion when the material constituting the cutting fuse wiring 203 is vaporized, the vaporizing cutting wiring The interlayer insulating film 216 and the upper interlayer insulating film 217 existing above the fuse wiring 203 are blown away, and a cavity 231 is formed.

  In the fuse element structure 10 of the present embodiment, in order to cut the cutting fuse wiring 203 in the cutting wiring area 3 of the fuse wiring 1c, when the laser beam in the infrared wavelength region is irradiated, the cutting fuse wiring 203 to be cut is cut. Laser reflecting regions 2 of adjacent fuse wirings 1b and 1d are arranged on both sides of the cut wiring region 3 of the arranged fuse wiring 1c. As shown in FIGS. 4 and 6, lasers of the fuse wirings 1b and 1d are arranged. The reflection region 2 does not overlap with the cutting fuse wires 202 and 204 of the fuse wires 1b and 1d in plan view. That is, since the cutting fuse wiring is not arranged in the lower layer portion of the laser reflecting region, a sufficient distance is ensured between the cutting fuse wiring 203 to be cut and the cutting fuse wirings 202 and 204 that are not cut.

  Therefore, in the fuse element structure 10 of this embodiment, even if the cutting fuse wiring 203 is cut by irradiating the cut wiring area 3 of the fuse wiring 1c with the laser beam in the infrared wavelength region, the fuse wiring 1c is disposed on both sides of the fuse wiring 1c. The fuse wirings 202 and 204 for cutting the fuse wiring 1b and the fuse wiring 1d are not easily damaged, and erroneous cutting of the cutting fuse wirings 202 and 204 is prevented.

  Further, in the fuse element structure 10 of the present embodiment, the arrangement of the cutting fuse wirings 201, 202, 203, 204 and the copper wirings 205, 206, 207, 208 constituting the fuse wirings 1a, 1b, 1c, 1d is as follows. The laser reflecting regions 2 of the adjacent fuse wirings 1b and 1d are arranged on both sides of the cut wiring region 3 where the cutting fuse wiring 203 to be cut is arranged so as to be reversed in the adjacent fuse wiring. Therefore, as shown in FIG. 4 and FIG. 6, the cutting fuse wiring 203 of the fuse wiring 1c to be cut and the cutting fuse wiring 201 of the fuse wiring 1a which is a cutting fuse wiring located adjacent thereto are Between them, the laser reflecting region 2 of the fuse wiring 1b is arranged.

  That is, in the fuse element structure 10 of this embodiment, the cutting fuse wiring located next to the cutting fuse wiring 203 to be cut is the fuse wirings 1b and 1d arranged on both sides of the fuse wiring 1c to be cut. Instead of the fuse wirings 202 and 204 for cutting, the fuse wiring 201 for cutting the fuse wiring 1a arranged at a position further away from the fuse wirings 1b and 1d arranged next to the fuse wiring 1c to be cut. Therefore, in the fuse element structure 10 of the present embodiment, the width of the fuse wiring 1b is adjacent to the width of the fuse wiring 1b between the cutting fuse wiring 203 to be cut and the cutting fuse wiring 201 located adjacent thereto. That is, the length of the interval S3 between the fuse wirings is separated, and the distance between the cutting fuse wiring 203 to be cut and the cutting fuse wiring 201 located adjacent thereto is sufficiently wide. Become. Therefore, even if the fuse wiring 203 for cutting the fuse wiring 1c is cut, the cutting fuse wiring 201 of the fuse wiring 1a located next to the cutting fuse wiring 203 is not easily damaged, and the cutting fuse wiring 201 is erroneously cut. Is prevented.

  Also in the fuse element structure 10 of the present embodiment, a crack 232 may occur in the interlayer insulating film 216 as shown in FIG. 6 due to an impact when the cavity 231 is formed. However, in the fuse element structure 10 of the present embodiment, even if the crack 232 is formed in the interlayer insulating film 216 in the vicinity of the cut fuse wiring 203 by cutting the fuse wiring 203 for cutting the fuse wiring 1c. Since the distance between the disconnected cutting fuse wiring 203 and the uncut cutting fuse wiring 201 located next to the cutting fuse wiring 203 is sufficiently secured, the crack 232 is formed in the cutting fuse wiring 201. It will be difficult to reach.

  As described above, in the fuse element structure 10 according to the present embodiment, it is possible to prevent erroneous disconnection of the fuse wirings 1b and 1d arranged on both sides of the fuse wiring 1c when cutting the fuse wiring 1c, which occurs when the fuse wiring 1c is disconnected. Therefore, the distance S3 between the fuse wirings 1a, 1b, 1c, and 1d can be sufficiently narrowed and can be arranged in a small area.

  As shown in FIG. 4, in the fuse element structure 10 of the present embodiment, when cutting the cutting fuse wiring 203, the copper wirings 206, 207 and 208 are also irradiated with a laser beam in the infrared wavelength region. . However, since the copper wirings 206, 207, and 208 have a very high reflectance with respect to the laser beam in the infrared wavelength region, the irradiated laser beam is reflected on the surfaces of the copper wirings 206, 207, and 208. Therefore, the irradiated laser beam does not damage the copper wirings 206, 207 and 208. Therefore, even if the interval S3 between adjacent fuse wirings is made narrower than before, the laser wiring is applied to the fuse wiring 1b adjacent to the fuse wiring 1c to be cut and the copper wirings 206 and 208 constituting the fuse wiring 1d. The fuse wiring 1b and the fuse wiring 1d are not damaged.

  In the laser beam spot 230, the irradiated laser beam reaches the silicon substrate constituting the semiconductor device in a region where the cutting fuse wiring 203 and the copper wirings 206, 207, 208 are not arranged. However, in this embodiment, since the laser beam in the infrared wavelength region is used as the laser beam, the silicon substrate is not damaged.

  In the fuse element structure 10 of the present embodiment, the cutting fuse wirings 201, 202, 203, and 204 constituting the fuse wirings 1a, 1b, 1c, and 1d are irradiated with laser beams in the infrared wavelength region. Since it is cut, there is no need to perform special processing on the copper wiring, for example, when the cutting fuse wiring is made of copper wiring. For this reason, the cutting fuse wirings 201, 202, 203, 204 and the copper wirings 205, 206, 207, 208 constituting the fuse wirings 1a, 1b, 1c, 1d are elements constituting a circuit other than the fuses. It is possible to use both. That is, the fuse wiring can be formed using the same layer as the gate electrode of the MOS transistor, the bit line of the DRAM, the wiring layer for forming the capacitor electrode, or the like. Therefore, the cutting fuse wires 201, 202, 203, 204 and the copper wires 205, 206, 207, 208 constituting the fuse element structure 10 of the present embodiment can be formed simultaneously with the wires used for the internal circuit of the semiconductor device. It will be a thing.

  Further, in the present embodiment, the wiring width of the copper wirings 205, 206, 207, 208 is wider than the wiring width of the cutting fuse wirings 201, 202, 203, 204. Both sides of the cut wiring region 3 of the central fuse wirings 1b and 1c are in a state of being sandwiched by a wide laser reflection region 2. For this reason, even if alignment misalignment occurs at the time of laser beam irradiation, it is possible to effectively prevent the fuse wiring that is not cut from being affected by the cutting fuse wiring, and the cutting that constitutes the cutting wiring region 3 of the predetermined fuse wiring. The fuse wiring can be cut more reliably.

In the present embodiment, the distance L2 between the contact plug 209 and the edge of the overlap region on the cutting fuse wiring 201, 202, 203, 204 side is in the range of 0.5 to 2.0 μm. In addition, it is possible to prevent the influence of the impact when cutting the fuse wirings 1a, 1b, 1c, and 1d from reaching the contact plug 209, and to sufficiently reduce the installation area of the fuse wirings 1a, 1b, 1c, and 1d.
On the other hand, for example, if the distance L2 between the contact plug 209 and the edge of the overlap region on the cutting fuse wiring 201, 202, 203, 204 side is shorter than the above range, for example, the cutting fuse wiring 203 is cut. In this case, since the distance between the contact plug 209 and the cavity 231 shown in FIG. 5 is reduced, the contact plug 209 may be affected by an impact when the cavity 231 is formed when the cutting fuse wiring 203 is cut. Specifically, when the cavity 231 is formed, the contact plug 209 is broken halfway, and a broken piece generated at the time of breakage adheres between both ends of the cut fuse wire 203 and the cut fuse wire is cut. 203 may become conductive again.

“Second Embodiment”
Next, a semiconductor device and a fuse element structure according to a second embodiment of the present invention will be described with reference to the drawings.
FIGS. 7 and 8 are enlarged views of other examples of the semiconductor device of the present invention, for explaining the fuse element structure of the present invention provided in the semiconductor device of the present invention. FIG. 7 is a plan view of the fuse element structure of the present invention, and FIG. 8 is a cross-sectional view taken along the line FF ′ of FIG.

  In FIG. 7, reference numeral 20 denotes a fuse element structure. As shown in FIG. 7, the fuse element structure 20 has four rows of fuse wirings 21, 22, 23 and 24 extending in the vertical direction in FIG. 7. As shown in FIG. 7 and FIG. 8, the fuse wirings 21, 22, 23, and 24 are the cutting fuse wirings 241d, 242d, 243d, and 244d, the first copper wirings 241b, 242b, 243b, 244b, and the second copper, respectively. Wirings 241c, 242c, 243c, and 244c are provided, and are arranged in parallel so that the interval between adjacent fuse wirings is constant.

  Further, in the present embodiment, the fuse wirings 21, 22, 23, and 24 are disposed in the opposite directions in the adjacent fuse wirings. Accordingly, the cutting fuse wirings 241d and 243d of the fuse wirings 21 and 23 are disposed above the cutting fuse wirings 242d and 244d of the fuse wirings 22 and 24 in FIG. The lengths of the copper wirings 241b and 243b are longer than those of the second copper wirings 241c and 243c. In the fuse wirings 22 and 24, the lengths of the first copper wirings 242b and 244b are shorter than those of the second copper wirings 242c and 244c. . As described above, in this embodiment, the upper and lower arrangements in FIG. 7 are different for each fuse wiring arranged in parallel, and the positions of the cutting fuse wirings 241d, 242d, 243d, and 244d are different for each fuse wiring. Are staggered.

  Similarly to the first embodiment, the cutting fuse wirings 241d, 242d, 243d, and 244d are cut by irradiating a laser beam in the infrared wavelength region, and tungsten silicide (WSi), polysilicon, titanium nitride. It consists of a single layer made of a material selected from (TiN) or a laminated film in which two or more layers are laminated.

  Further, as shown in FIG. 7, the first copper wiring and the second copper wiring have a wiring width wider than that of the cutting fuse wirings 241d, 242d, 243d, and 244d. The first copper wiring and the second copper wiring are formed by using the damascene method in the same manner as the copper wiring of the first embodiment, and as shown in FIG. 8 (not shown in FIG. 7). The side and bottom surfaces are covered with the barrier metal 243a.

  Further, as shown in FIG. 8, the cutting fuse wirings 241d, 242d, 243d, and 244d are provided on a lower interlayer insulating film 252 made of a silicon oxide film or the like provided on a silicon substrate constituting the semiconductor device. In addition, the first copper wirings 241b, 242b, 243b, 244b and the second copper wirings 241c, 242c are provided above the cutting fuse wirings 241d, 242d, 243d, 244d via an interlayer insulating film 253 made of a silicon oxide film or the like. 243c and 244c are provided.

  Further, as shown in FIGS. 7 and 8, each fuse wiring 21, 22, 23, 24 includes a cutting fuse wiring 241d, 242d, 243d, 244d and a first copper wiring 241b, 242b, 243b, 244b. A first overlap region 51 that overlaps in plan view, and a second overlap region 52 that overlaps the fuse wirings 241d, 242d, 243d, and 244d for cutting and the second copper wires 241c, 242c, 243c, and 244c in plan view are provided. It has been. A contact plug 251 that penetrates the interlayer insulating film 253 is provided in the first overlap region 51, and a contact plug 250 that penetrates the interlayer insulating film 253 is provided in the second overlap region 52.

  The contact plug 250 is provided at the end of the second overlap region 52 near the direction in which the second copper wiring extends in order to sufficiently reduce the installation area of the fuse wirings 21, 22, 23, and 24. The contact plug 251 has an end portion near the direction in which the first copper wiring side in the first overlap region 51 extends in order to sufficiently reduce the installation area of the fuse wirings 21, 22, 23, 24. Is provided. The contact plugs 250 and 251 are made of a conductive material such as tungsten (W) or phosphorous doped polysilicon, like the copper wiring of the first embodiment. Then, the cutting fuse wirings 241d, 242d, 243d, and 244d constituting the fuse wirings 21, 22, 23, and 24 and the second copper wirings 241c, 242c, 243c, and 244c are connected via the contact plug 250, The cutting fuse wirings 241d, 242d, 243d, 244d and the first copper wirings 241b, 242b, 243b, 244b are connected through the contact plug 251. In addition, the length L3 of the 1st overlap area | region 51 and the 2nd overlap area | region 52 is made into the preferable dimension similarly to 1st Embodiment.

Further, as shown in FIG. 8, an upper interlayer insulating film 254 made of a silicon oxide film or the like is provided on the first copper wiring and the second copper wiring. As in the first embodiment, the upper interlayer insulating film 254 includes a first interlayer insulating film having the same thickness as the first copper wiring and the second copper wiring, and the first copper wiring and the second copper are formed on the first interlayer insulating film. It has a two-layer structure (not shown) with a second interlayer insulating film formed after the wiring is buried.
Also in the present embodiment, as in the first embodiment, the upper interlayer insulating film 254 is formed in a region including a portion overlapping the region including the cut wiring region 3 in plan view, as shown in FIGS. The thin film region 240 is provided, and the thick film region 240 a is thicker than the thin film region 240. Further, as shown in FIG. 8, a surface protective film 255 made of silicon oxynitride (SiON), polyimide, or the like is provided on the thick film region 240a of the upper interlayer insulating film 254.

Each of the fuse wirings 21, 22, 23, and 24 has a laser reflection region 2 and a cut wiring region 3 as shown in FIGS. The laser reflection region 2 is a region located on the first copper wiring and the second copper wiring that do not overlap the cutting fuse wirings 241d, 242d, 243d, and 244d in plan view. The cut wiring region 3 is a region located on the cutting fuse wirings 241d, 242d, 243d, and 244d that do not overlap the first copper wiring and the second copper wiring in plan view.
In the present embodiment, unlike the first embodiment, as shown in FIGS. 7 and 8, a first overlap region 51 is disposed at one end of the cut wiring region 3, and the other end of the cut wiring region 3. The second overlap area 52 is arranged in the two, and the overlap areas are arranged at both ends of the cut wiring area 3. Here, in the overlap region (the region indicated by L3 in FIGS. 7 and 8) where the first copper wiring and the second copper wiring overlap with the cutting fuse wiring in a plan view, the upper layer is a copper wiring. Although it has a reflection function, it is not included in the laser reflection region 2 for the sake of clarity of explanation.

  In the present embodiment, as shown in FIG. 7, in the central fuse wirings 22 and 23 in which other fuse wirings are arranged on both sides of the four rows of fuse wirings 21, 22, 23 and 24, cut wiring The laser reflection regions 2 of the fuse wirings adjacent to both sides of the region 3 are arranged. Therefore, as shown in FIGS. 7 and 8, the distance between the cutting fuse wiring 241d constituting the cutting wiring area 3 of the fuse wiring 21 and the cutting fuse wiring 243d constituting the cutting wiring area 3 of the fuse wiring 23 is The interval between the cutting fuse wiring 242d constituting the cutting wiring area 3 of the fuse wiring 22 and the cutting fuse wiring 244d constituting the cutting wiring area 3 of the fuse wiring 24 is sufficiently wide.

Similarly to the first embodiment, both ends of each of the fuse wirings 21, 22, 23, and 24 are connected to an internal circuit including a transistor of the semiconductor device, a power supply wiring, a ground potential (GND) wiring, and the like. . The fuse wirings 21, 22, 23, 24 are in a conductive state in the initial state, and the fuse wirings 21, 22, 23, 24 are disconnected, so that a circuit having a specific function for replacement ( Redundant circuit) is activated.
The fuse element structure shown in FIGS. 7 and 8 can be manufactured in the same manner as in the first embodiment.

Next, the operation in the case of cutting the fuse wiring constituting the fuse element structure shown in FIGS. 7 and 8 will be described.
In the present embodiment, a case where the second fuse wiring 22 from the left in which other fuse wirings are arranged on both sides of the four rows of fuse wirings 21, 22, 23, 24 will be described as an example. .
In the present embodiment, the fuse wiring 22 is cut by irradiating the cutting fuse wiring 242d constituting the cutting wiring area 3 of the fuse wiring 22 with a laser beam spot 259 in the infrared wavelength region, as in the first embodiment. It is done by doing.
At this time, similarly to the first embodiment, in the vicinity of the cutting fuse wiring 242d irradiated with the laser beam, the cutting fuse wiring vaporized by the volume expansion when the material constituting the cutting fuse wiring 242d is vaporized. The interlayer insulating film 223 and the upper interlayer insulating film 254 existing on the upper part of 242d are blown off, and a cavity is formed.

  In the fuse element structure 20 of the present embodiment, in order to cut the cutting fuse wiring 242d of the cutting wiring region 3 of the fuse wiring 22, the cutting wiring region 3 is cut when irradiated with a laser beam in the infrared wavelength region. The laser reflection areas 2 of the adjacent fuse wirings 21 and 23 are arranged on both sides of the cut wiring area 3 of the fuse wiring 22 in which the fuse wiring 242d is arranged. As shown in FIGS. The laser reflection regions 2 of 21 and 23 do not overlap with the cutting fuse wires 241d and 243d of the fuse wires 21 and 23 in plan view. That is, since the cutting fuse wiring is not arranged in the lower layer portion of the laser reflection region, a sufficient distance is ensured between the cutting fuse wiring 242d to be cut and the cutting fuse wirings 241d and 243d that are not cut.

  Further, in the fuse element structure 20 of the present embodiment, the laser reflection regions 2 of the adjacent fuse wirings 21 and 23 are arranged on both sides of the cutting wiring region 3 where the cutting fuse wiring 242d to be cut is arranged. As shown in FIGS. 7 and 8, there is a laser reflection region between the cutting fuse wiring 242d to be cut and the cutting fuse wiring 244d of the fuse wiring 24 which is a cutting fuse wiring located adjacent thereto. 2 is arranged. Accordingly, the distance between the cutting fuse wiring 242d to be cut and the cutting fuse wiring 244d located adjacent thereto is sufficiently large. Therefore, even if the cutting fuse wiring 242d of the fuse wiring 22 is cut, the cutting fuse wiring 244d of the fuse wiring 21 located next to the cutting fuse wiring 242d is not easily damaged, and the cutting fuse wiring 244d is erroneously cut. Is prevented.

  Further, in the fuse element structure 20 of the present embodiment, even if a crack is formed in the interlayer insulating film 253 in the vicinity of the cut fuse wire 242d, the cut fuse wire 242d and the cut fuse wire 242d are cut. Since a sufficient distance from the adjacent cutting fuse wiring 244d that is not cut is secured, it is difficult for cracks to reach the cutting fuse wiring 244d.

  As described above, in the fuse element structure 20 of the present embodiment, it is possible to prevent erroneous disconnection of the fuse wirings 21 and 23 arranged on both sides of the fuse wiring 22 when the fuse wiring 22 is cut, and this occurs when the fuse wiring 22 is cut. Therefore, the distance between the fuse wirings 21, 22, 23, and 24 can be sufficiently narrowed and can be arranged in a small area.

  In the fuse element structure 20 of the present embodiment, when the cutting fuse wiring 242d is cut, the first copper wirings 241b, 242b, 243b, and the second copper wiring 242c are also irradiated with laser beams in the infrared wavelength region. The However, the irradiated laser beam is reflected by the surfaces of the first copper wirings 241b, 242b, 243b and the second copper wiring 242c. Therefore, even if the first copper wirings 241b and 243b constituting the fuse wirings 21 and 23 adjacent to the fuse wiring 22 to be cut are irradiated with a laser beam, the fuse wirings 21 and 23 are not damaged. .

  Further, in the fuse element structure 20 of the present embodiment, the first overlap region 51 is disposed at one end of the cut wiring region 3 and the second overlap region 52 is disposed at the other end of the cut wiring region 3. The cut wiring region 3 of the fuse wirings 21, 22, 23, 24 is in a state surrounded by the first copper wiring and the second copper wiring when both sides and both ends are viewed in plan. For example, both sides and both ends of the cut wiring region 3 of the fuse wiring 22 are surrounded by the first copper wirings 241b, 242b, 243b and the second copper wiring 242c as shown in FIG. It has become. For this reason, in the fuse element structure 20 of the present embodiment, even when a misalignment occurs within the range in which the laser beam spot 259 includes the cutting region 3 during laser beam irradiation, only the cutting region 3 is irradiated with the laser beam. Since it can be heated, the fuse wirings 21, 22, 23, and 24 can be accurately cut in the cut wiring region 3.

“Third Embodiment”
Next, a semiconductor device and a fuse element structure according to a third embodiment of the present invention will be described with reference to the drawings.
9 and 10 are enlarged views of a part of another example of the semiconductor device of the present invention. FIG. 9 is a plan view of the semiconductor device of the present invention, and FIG. 10 is a cross-sectional view taken along the line GG ′ of FIG.

  A semiconductor device 3 a shown in FIGS. 9 and 10 has a fuse element structure 30. The fuse element structure 30 has four rows of fuse wirings 31, 32, 33, and 34 extending in the vertical direction in FIG. As shown in FIGS. 9 and 10, the fuse wirings 31, 32, 33, and 34 are connected to the cutting fuse wirings 261d, 262d, 263d, and 264d, the first copper wirings 261b, 262b, 263b, 264b, and the second copper, respectively. Wirings 261c, 262c, 263c, and 264c are provided, and are arranged in parallel so that the interval between adjacent fuse wirings is constant.

  In the present embodiment, the fuse wirings 31, 32, 33, and 34 are disposed so as to be opposite to each other in the adjacent fuse wiring. Accordingly, the cutting fuse wirings 261d and 263d of the fuse wirings 31 and 33 are arranged above the cutting fuse wirings 262d and 264d of the fuse wirings 32 and 34 in FIG. The copper wirings 261b and 263b are disposed above the second copper wirings 261c and 263c. In the fuse wirings 32 and 34, the first copper wirings 262b and 264b are disposed below the second copper wirings 262c and 264c. As described above, in this embodiment, the upper and lower arrangements in FIG. 9 are different for each fuse wiring arranged in parallel, and the positions of the cutting fuse wirings 261d, 262d, 263d, and 264d are different for each fuse wiring. Are staggered.

  Similarly to the first embodiment, the cutting fuse wirings 261d, 262d, 263d, and 264d are cut by irradiating a laser beam in the infrared wavelength region, and tungsten silicide (WSi), polysilicon, titanium nitride. It consists of a single layer made of a material selected from (TiN) or a laminated film in which two or more layers are laminated.

  Further, as shown in FIG. 9, the first copper wiring and the second copper wiring have a wiring width wider than that of the cutting fuse wirings 261d, 262d, 263d, and 264d. The first copper wiring and the second copper wiring are formed by using the damascene method in the same manner as the copper wiring of the first embodiment, and as shown in FIG. 10 (not shown in FIG. 9). The side and bottom surfaces are covered with the barrier metal 263a.

  The fuse element structure 30 is provided on a semiconductor substrate 279 as shown in FIG. The semiconductor substrate 279 is made of P-type silicon and is formed with an element isolation region 278 in which an insulating film is embedded and diffusion layers 261e, 262e, 263e, and 264e shown in FIGS. . In the diffusion layers 261e, 262e, 263e, and 264e, an N-type impurity made of phosphorus or arsenic is introduced in order to lower the electric resistance value. As shown in FIG. 10, a lower interlayer insulating film 272 made of a silicon oxide film or the like is formed on the semiconductor substrate 279. Cutting fuse wirings 261d, 262d, 263d, and 264d are provided on the lower interlayer insulating film 272. Further, the first copper wirings 261b, 262b, 263b, 264b and the second copper wirings 261c, 262c are provided above the cutting fuse wirings 261d, 262d, 263d, 264d via an interlayer insulating film 273 made of a silicon oxide film or the like. 263c, 264c are provided.

Further, as shown in FIGS. 9 and 10, each of the fuse wirings 31, 32, 33, 34 includes a cutting fuse wiring 261d, 262d, 263d, 264d and a first copper wiring 261b, 262b, 263b, 264b. An overlap region 53 that overlaps in plan view is provided. A contact plug 270 that penetrates the interlayer insulating film 273 is provided in the overlap region 53.
The contact plug 270 is closer to the direction in which the first copper wirings 261b, 262b, 263b, 264b in the overlap region 53 extend in order to sufficiently reduce the installation area of the fuse wirings 31, 32, 33, 34. Is provided at the end. The contact plug 270 is made of a conductive material such as tungsten (W) or phosphorous doped polysilicon, like the copper wiring of the first embodiment. In addition, the length L4 of the overlap area | region 53 is made into the preferable dimension similarly to 1st Embodiment.

Each fuse wiring 31, 32, 33, 34 is provided with an overlapping region 54 where the cutting fuse wirings 261d, 262d, 263d, 264d and the diffusion layers 261e, 262e, 263e, 264e overlap in plan view. Yes. A first connection plug 271 that penetrates the lower interlayer insulating film 272 is provided in the overlap region 54. The first connection plug 271 is cut together with the cutting fuse wirings 261d, 262d, 263d, and 264d by irradiating a laser beam in the infrared wavelength region.
Each fuse wiring 31, 32, 33, 34 is provided with an overlap region 55 where the second copper wirings 261c, 262c, 263c, 264c and the diffusion layers 261e, 262e, 263e, 264e overlap in plan view. Yes. In the overlap region 55, a second connection plug 282 that penetrates the interlayer insulating film 273 and the lower interlayer insulating film 272 is provided.

  The first connection plug 271 and the second connection plug 282 are made of a conductive material such as tungsten (W) or polysilicon doped with phosphorus. The lengths of the overlap regions 54 and 55 are set so as to be optimal according to the materials and film thicknesses of the cutting fuse wirings 261d, 262d, 263d, and 264d, the interlayer insulating film 273, and the lower interlayer insulating film 272. Is done.

  Then, one end of the cutting fuse wirings 261d, 262d, 263d, and 264d constituting each of the fuse wirings 31, 32, 33, and 34 and the first copper wirings 261b, 262b, 263b, and 264b are connected via the contact plug 270. The other end of the cutting fuse wirings 261d, 262d, 263d, 264d and the diffusion layers 261e, 262e, 263e, 264e are connected through the first connection plug 271 and disconnected through the second connection plug 282. The diffusion layers 261e, 262e, 263e, and 264e are connected to the ends of the second copper wirings 261c, 262c, 263c, and 264c facing the other ends of the fuse wirings 261d, 262d, 263d, and 264d in plan view.

Further, as shown in FIG. 10, an upper interlayer insulating film 274 made of a silicon oxide film or the like is provided on the first copper wiring and the second copper wiring. Similar to the first embodiment, the upper interlayer insulating film 274 includes a first interlayer insulating film having the same film thickness as the first copper wiring and the second copper wiring, and the first copper wiring and the second copper on the first interlayer insulating film. It has a two-layer structure (not shown) with a second interlayer insulating film formed after the wiring is buried.
Also in the present embodiment, as in the first embodiment, the upper interlayer insulating film 274 is formed in a region including a portion overlapping the region including the cut wiring region 3 in plan view, as shown in FIGS. The thin film region 260 is provided, and the thick film region 260 a is thicker than the thin film region 260. Further, as shown in FIG. 10, a surface protective film 275 made of silicon oxynitride (SiON), polyimide, or the like is provided on the thick film region 260a of the upper interlayer insulating film 274.

  Each of the fuse wirings 31, 32, 33, and 34 has a laser reflection region 2 and a cut wiring region 3 as shown in FIGS. The laser reflection region 2 is a region located on the first copper wiring and the second copper wiring that do not overlap the cutting fuse wirings 261d, 262d, 263d, and 264d in plan view. The cut wiring region 3 is a region located on the cutting fuse wirings 261d, 262d, 263d, and 264d that do not overlap the first copper wiring and the second copper wiring in plan view. Here, the overlap region (the region indicated by L4 in FIGS. 9 and 10) where the first copper wiring and the cutting fuse wiring overlap in plan view has a function of reflecting the laser beam because the upper layer is the copper wiring. However, for clarity of explanation, it is not included in the laser reflection area.

The semiconductor device 3a shown in FIGS. 9 and 10 can be manufactured as follows, for example.
First, an element isolation region 278 in which an insulating film is embedded using an STI (Shallow Trench Isolation) method or the like, and diffusion layers 261e, 262e, 263e, and 264e into which an N-type impurity made of phosphorus or arsenic is introduced are formed. A semiconductor substrate 279 made of P-type silicon is prepared.

  Next, as shown in FIG. 10, a lower interlayer insulating film 272 is formed on the element isolation region 278 and the diffusion layers 261e, 262e, 263e, and 264e of the semiconductor substrate 279, and the first connection plug 271 and the second connection plug are formed. A contact hole serving as a lower portion of 282 is formed by a known means, and the contact hole is filled with a conductive material. Subsequently, cutting fuse wirings 261d, 262d, 263d, and 264d are formed on the lower interlayer insulating film 272 by using a photolithography method and a dry etching method. Thereafter, an interlayer insulating film 273 is formed on the cutting fuse wirings 261d, 262d, 263d, and 264d, and the surface is planarized by CMP. Thereafter, contact holes to be upper portions of the contact plug 270 and the second connection plug 282 are formed by a known means, and the contact hole is filled with a conductive material.

Subsequently, a first interlayer insulating film having the same thickness as the first copper wiring and the second copper wiring is formed on the interlayer insulating film 273. Thereafter, using the damascene method, the first copper wiring and the second copper wiring whose side surfaces and bottom surface are covered with the barrier metal are formed so as to be embedded in the first interlayer insulating film. Subsequently, a second interlayer insulating film is formed on the first copper wiring and the second copper wiring. In this way, the first copper wiring and the second copper wiring, and the upper interlayer insulating film 274 having a two-layer structure (not shown) of the first interlayer insulating film and the second interlayer insulating film are formed.
Thereafter, in the same manner as in the first embodiment, the upper interlayer insulating film 274 having the thin film region 260 and the thick film region 260a and the surface protective film 275 provided only on the thick film region 260a are formed on the upper interlayer insulating film 274. And form.
Through the above steps, the semiconductor device 3a shown in FIGS. 9 and 10 is obtained.

  In the present embodiment, the second connection plug 282 that penetrates the lower interlayer insulating film 272 and the interlayer insulating film 273 is divided into two parts, ie, a part that penetrates the lower interlayer insulating film 272 and a part that penetrates the interlayer insulating film 273. However, after forming the interlayer insulating film 273, a contact hole penetrating the lower interlayer insulating film 272 and the interlayer insulating film 273 is formed by one process, and the contact hole is filled with a conductive material. May be.

Next, the operation in the case of cutting the fuse wiring constituting the fuse element structure provided in the semiconductor device 3a shown in FIGS. 9 and 10 will be described with reference to the drawings.
11 is a view for explaining a state after the cutting fuse wiring of the fuse element structure shown in FIG. 9 is cut, and is a cross-sectional view taken along the line GG ′ of FIG.

In the present embodiment, the case where the second fuse wiring 33 from the right in which other fuse wirings are arranged on both sides of the four rows of fuse wirings 31, 32, 33, 34 will be described as an example. .
In the present embodiment, as shown in FIG. 9, the fuse wiring 33 is cut by applying a laser beam in the infrared wavelength region to the cutting fuse wiring 263 d and the first connection plug 271 constituting the cutting wiring region 3 of the fuse wiring 33. This is done by irradiating the spot 279.

  When the cutting fuse wiring 263d and the first connection plug 271 are irradiated with a laser beam in the infrared wavelength region, the material constituting the connection portion of the first connection plug 271 with the cutting fuse wiring 262d and the cutting fuse wiring 263d The material constituting the material is heated by absorbing the laser beam and vaporized. At this time, also in the present embodiment, as shown in FIG. 11, in the vicinity of the cutting fuse wiring 263d irradiated with the laser beam, the interlayer insulating film 273 and the upper interlayer existing above the vaporized cutting fuse wiring 262d. The insulating film 244 is blown away, and a cavity 280 is formed. A part of the first connection plug 271 is heated and evaporated at the same time as the cutting fuse wiring 263d, but the connection part with the diffusion layer 263e remains. In the present embodiment, the cutting fuse wiring 263d is not cut in two, but the connecting portion between the cutting fuse wiring 263d and the first connection plug 271 is cut, whereby the fuse wiring 33 is formed. Disconnected.

  In the fuse element structure 30 provided in the semiconductor device 3 a of the present embodiment, a laser beam in the infrared wavelength region is used to cut the fuse wiring 33, the cutting fuse wiring 263 d in the cutting wiring area 3 of the fuse wiring 33 and the first When the connection plug 271 is irradiated, the laser reflection region 2 of the adjacent fuse wirings 32 and 34 on both sides of the cutting wiring region 263d to be cut and the cutting wiring region 3 of the fuse wiring 33 in which the first connection plug 271 is disposed. 9 and 10, a sufficient distance is ensured between the cutting fuse wiring 263 d to be cut and the cutting fuse wirings 262 d and 264 d that are not cut.

  In the fuse element structure 30 of the present embodiment, the laser reflection regions 2 of the adjacent fuse wirings 32 and 34 are arranged on both sides of the cut wiring region 3 of the fuse wiring 33 irradiated with the laser beam in the infrared wavelength region. Therefore, as shown in FIGS. 9 and 10, there is a laser between the cutting fuse wiring 263d to be cut and the cutting fuse wiring 261d of the fuse wiring 31 which is a cutting fuse wiring located adjacent to the cutting fuse wiring 263d. The reflection area 2 is arranged. Therefore, the distance between the cutting fuse wiring 263d to be cut and the cutting fuse wiring 261d located adjacent thereto is sufficiently large. Therefore, even if the cutting fuse wiring 263d of the fuse wiring 33 is cut, the cutting fuse wiring 261d of the fuse wiring 31 located next to the cutting fuse wiring 263d is not easily damaged, and the cutting fuse wiring 261d is erroneously cut. Is prevented.

  In the fuse element structure 30 of the present embodiment, even if a crack is formed in the interlayer insulating film 273 near the cut fuse wiring 263d, the cut fuse wiring 263d and the cut fuse wiring 263d are disconnected. Since a sufficient distance from the adjacent cutting fuse wiring 261d that is not cut is ensured, it is difficult for cracks to reach the cutting fuse wiring 261d.

  As described above, in the fuse element structure 30 of the present embodiment, it is possible to prevent erroneous disconnection of the fuse wirings 32 and 34 arranged on both sides of the fuse wiring 33 when the fuse wiring 33 is cut, and this occurs when the fuse wiring 33 is cut. Therefore, the distance between the fuse wirings 31, 32, 33, and 34 can be made sufficiently narrow and can be arranged in a small area.

  Further, in the fuse element structure 30 of the present embodiment, when the connecting portion between the cutting fuse wiring 263d of the fuse wiring 33 and the first connection plug 271 is cut, as shown in FIG. 9, the first copper wiring 263b is used. The second copper wirings 262c, 263c, 264c are also irradiated with a laser beam in the infrared wavelength region. However, the irradiated laser beam is reflected on the surfaces of the first copper wiring 263b and the second copper wiring 262c, 263c, 264c. Therefore, even if the second copper wires 262c and 264c constituting the fuse wires 32 and 34 adjacent to the fuse wire 33 to be cut are irradiated with a laser beam, the fuse wires 32 and 34 are not damaged. .

  Further, in the laser beam spot 279, in the region where the cutting fuse wiring 263d, the first copper wiring 263b, the second copper wiring 262c, 263c, and 264c are not arranged, the irradiated laser beam is a semiconductor constituting the semiconductor device 3a. The substrate 279 is reached. However, in this embodiment, since the laser beam in the infrared wavelength region is used as the laser beam, the semiconductor substrate 279 on which the diffusion layer 263e is formed is not damaged.

  Further, as shown in FIG. 9, the semiconductor device 3a of the present embodiment has a portion of the cutting fuse wiring exposed from the overlap region of the first copper wiring and the cutting fuse wiring in the plan view of the fuse wiring. Only (cutting region 3) is cut by laser beam irradiation. Therefore, as in the case of the second embodiment, even if the alignment misalignment occurs within the range where the laser beam spot 279 includes the cutting region 3, only the cutting region 3 can be heated by the laser beam. The fuse wirings 21, 22, 23, and 24 can be accurately cut in the cut wiring region 3. Furthermore, in the present embodiment, only the contact portion between the first connection plug 271 and the cutting fuse wiring 262d only needs to be brought into a non-conductive state by irradiation with a laser beam in the infrared wavelength region. In addition, compared with the case where the wiring itself is completely cut, there is an effect that the margin for the low laser beam irradiation power is improved. That is, even if the power of the laser beam reaching the fuse portion is attenuated due to the film thickness variation of the interlayer insulating film in the fuse formation region, the fuse can be surely cut.

  As an application example of the present invention, a semiconductor device such as a semiconductor device having a fuse element structure for operating an internal circuit having a specific function can be cited. Further, the fuse element structure of the present invention is not limited to application to a storage device such as a DRAM or a flash memory, and uses a fuse that can be cut by a laser beam even for a logic device or the like that does not have a memory cell. Any device that can be used.

FIG. 1 is a plan view of the fuse element structure of the present invention. FIG. 2 is a sectional view taken along line B-B ′ of FIG. 1. FIG. 3 is a sectional view taken along line C-C ′ of FIG. 1. FIG. 4 is a plan view for explaining an example of the spot position of the laser beam irradiated to cut the fuse wiring constituting the fuse element structure. FIG. 5 is a diagram for explaining a state after the fuse wiring is cut, and is a cross-sectional view taken along the line D-D ′ in FIG. 4 (corresponding to the line B-B ′ in FIG. 1). 6 is a diagram for explaining a state after the fuse wiring is cut, and is a cross-sectional view taken along the line E-E ′ of FIG. 4 (corresponding to the C-C ′ line of FIG. 1). FIG. 7 is a plan view of the fuse element structure of the present invention. FIG. 8 is a cross-sectional view taken along the line F-F ′ of FIG. 7. FIG. 9 is a plan view of the semiconductor device of the present invention. 10 is a cross-sectional view taken along the line G-G ′ of FIG. 9. 11 is a view for explaining a state after the cutting fuse wiring of the fuse element structure shown in FIG. 9 is cut, and is a cross-sectional view taken along the line G-G ′ of FIG. 9. FIG. 12 is a cross-sectional view of a copper wiring formed using the damascene method. FIG. 13 is a plan view showing an example of a conventional fuse wiring. FIG. 14 is a drawing showing an example of a fuse element structure having a fuse wiring in which a protective layer is provided on a part of the fuse wiring. FIG. 14 (a) is a plan view, and FIG. FIG. 14B is a cross-sectional view taken along the line AA ′ in FIG. 15 is a cross-sectional view taken along line A-A ′ of FIG. 14A after cutting the central fuse wiring in the fuse element structure shown in FIG. 14.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 1d, 21, 22, 23, 24, 31, 32, 33, 34 ... fuse wiring, 2 ... laser reflection area | region, 3 ... cutting wiring area | region, 3a ... semiconductor device 10, 20, 30 ... Fuse element structure, 51 ... first overlap region, 52 ... second overlap region, 53, 54, 55 ... overlap region, 101, 124, 125, 216, 253, 273 ... interlayer insulating film, 102 ... wiring trench , 103, 206a, 207a, 208a, 243a, 263a ... barrier metal, 104, 205, 206, 207, 208 ... copper wiring, 105, 106, 107 ... aluminum wiring, 108, 259, 279 ... spot, 120, 121, 122: fuse wiring, 120a, 121a, 122a ... protective layer, 130, 231, 280 ... cavity, 131, 232 Crack, 201, 202, 203, 204, 241d, 242d, 243d, 244d, 261d, 262d, 263d, 264d ... cutting fuse wiring, 209, 250, 251, 270 ... contact plug, 217, 254, 274 ... upper interlayer Insulating film, 215, 252, 272 ... Lower interlayer insulating film, 218, 255, 275 ... Surface protective film, 220, 240, 260 ... Thin film region, 220a, 240a, 260a ... Thick film region, 241b, 242b, 243b, 244b , 261b, 262b, 263b, 264b ... first copper wiring, 241c, 242c, 243c, 244c, 261c, 262c, 263c, 264c ... second copper wiring, 279 ... semiconductor substrate, 278 ... isolation region, 261e, 262e, 263e 264e ... diffusion layer, 271 ... first connection Rug, 282 ... the second connection plug.

Claims (7)

A fuse element structure having at least three rows of fuse wirings,
Each fuse wiring is cut by irradiating a laser beam in the infrared wavelength region, and a cutting fuse wiring,
A copper wiring disposed above the cutting fuse wiring via an interlayer insulating film,
In the overlap region where the cutting fuse wiring and the copper wiring overlap in plan view, the cutting fuse wiring and the copper wiring are connected via a contact plug that penetrates the interlayer insulating film,
A laser reflecting region located on the copper wiring not overlapping with the cutting fuse wiring in plan view; and a cutting wiring region positioned on the cutting fuse wiring not overlapping with the copper wiring in plan view. ,
In the central fuse wiring in which other fuse wirings are arranged on both sides of the at least three rows of fuse wirings, the laser reflection regions of adjacent fuse wirings are arranged on both sides of the cut wiring region. Fuse element structure.   2. The fuse element structure according to claim 1, wherein a side surface and a bottom surface of the copper wiring are covered with a barrier metal. An upper interlayer insulating film is provided on the copper wiring,
The upper interlayer insulating film has a thin film region provided in a portion overlapping at least a region including the cut wiring region in plan view, and a thick film region having a thickness greater than the thin film region,
The fuse element structure according to claim 1, wherein a surface protective film is provided on the thick film region.   The fuse element structure according to any one of claims 1 to 3, wherein overlap regions are arranged at both ends of the cut wiring region.   A semiconductor device comprising the fuse element structure according to claim 1 on a semiconductor substrate. A semiconductor device comprising the fuse element structure according to any one of claims 1 to 3 on a semiconductor substrate,
One end of the cutting fuse wiring is connected to a diffusion layer provided on the semiconductor substrate via a first connection plug that penetrates a lower interlayer insulating film provided on the diffusion layer,
An end of the copper wiring facing one end of the cutting fuse wiring in a plan view is connected to the diffusion layer through a second connection plug that penetrates the lower interlayer insulating film and the interlayer insulating film A semiconductor device which is characterized by being made.   7. The semiconductor device according to claim 6, wherein a connection portion of the first connection plug with the cutting fuse wiring is cut by irradiating a laser beam in an infrared wavelength region.

Images