JP2010027945A - Semiconductor device and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device, having a fuse to be cut through laser irradiation, wherein the fuse is prevented from scattering by suppressing a decrease in energy applied to the fuse by suppressing an increase in reflectivity of laser light. <P>SOLUTION: On an insulating film 1, the fuse 11 is formed of a contact layer 2a, a metal layer 3a, and a TiN antireflective film 4a. On the insulating film 1, a silicon oxide film 5 is formed covering the fuse 11. A silicon nitride film 8 is formed on the silicon oxide film 5. A silicon oxide film 5a positioned on the fuse 11 is triangularly sectioned in the short-side direction of the fuse 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly to a semiconductor device having a laser fuse element and a manufacturing method thereof.

  With increasing demand for higher functionality of electronic devices such as mobile phones and digital cameras, adjustment of circuit functions by fuse elements has been frequently used in order to realize semiconductor integrated circuit devices having high functionality. Yes. Such a semiconductor integrated circuit device has been put to practical use by mounting a fuse circuit having a plurality of fuses in advance and cutting the fuse by laser irradiation after an operation test or the like (see, for example, Patent Document 1). ).

  A method of manufacturing a conventional semiconductor device having such a fuse will be described with reference to process cross-sectional views of FIGS.

  First, as shown in FIG. 14, an adhesion layer 102 made of Ti and TiN, a metal layer 103 containing Al as a main component, and an antireflection film 104 made of TiN are sequentially formed on an insulating film 101 made of a silicon oxide film. accumulate.

  Subsequently, as shown in FIG. 15, the antireflection film 104, the metal layer 103, and the adhesion layer 102 are etched using a photoresist (not shown) as a mask, so that the adhesion layer 102a, the metal layer 103a, and the antireflection film are etched. At the same time as forming the fuse 111 composed of the film 104a, the wiring 112 composed of the adhesion layer 102b, the metal layer 103b, and the antireflection film 104b is formed, and then the above-described photoresist is removed.

  Next, as shown in FIG. 16, a silicon oxide film 105 is deposited on the insulating film 101 by a P-CVD (plasma-chemical vapor deposition) method so as to cover the fuse 111 and the wiring 112, and then chemically and mechanically. The surface of the silicon oxide film 105 is planarized by a polishing method or the like, and then a silicon nitride film 106 is deposited on the silicon oxide film 105.

  Subsequently, as shown in FIG. 17, the silicon nitride film 106 and the silicon oxide film 105 are etched so that the antireflection film 104a of the fuse 111 is exposed using a photoresist (not shown) having an opening in the fuse region as a mask. After the above, the aforementioned photoresist is removed. As a result, a fuse upper opening 107 reaching the fuse 111 is formed.

Next, as shown in FIG. 18, a silicon nitride film 108 is deposited as a protective film for the fuse region on the bottom and side walls of the fuse upper opening 107 and on the silicon nitride film 106.
JP 2005-209903 A

  However, in the conventional method of manufacturing the semiconductor device shown in FIGS. 14 to 18, the insulating film is etched until the upper portion of the fuse is exposed, and as a result, the antireflection film, that is, the TiN film constituting the upper portion of the fuse is removed. End up. As a result, if the TiN film disappears and the reflectivity of the laser from the fuse increases, the energy applied to the fuse decreases, and the fuse that melts in a state where the temperature rise is insufficient (hereinafter referred to as fuse fuse). Scattering). Further, when the fuses are scattered, it is necessary to widen the interval between the fuses to avoid a short circuit between the fuses, so that there is a problem that the chip size is particularly increased in a chip that frequently uses fuses.

  The TiN film serving as the antireflection film 104a also serves as an antireflection film for processing the fuse 111 into a desired dimension in the photolithography process. Therefore, the thickness of the TiN film is a reflectance in the photolithography process. Since the thickness is set to be low (about 30 nm in the case of i-line), it is difficult to form the TiN film thick in advance.

  In view of the above, according to the present invention, in a semiconductor device including a fuse that is cut by laser irradiation, it is possible to prevent scattering of the fuse by suppressing an increase in the reflectance of the laser and suppressing a decrease in energy applied to the fuse. The purpose is to.

  In order to achieve the above object, a semiconductor device according to the present invention includes a first insulating film formed on a semiconductor substrate, a first insulating film, and a TiN film on the surface. And a fuse mainly composed of Al, a wiring formed on the first insulating film, and a second insulating film formed on the first insulating film so as to cover the fuse and the wiring A third insulating film formed on the second insulating film except on the fuse and its peripheral region; on the second insulating film located on the fuse and its peripheral region; and And a fourth insulating film formed on the third insulating film, and a cross section in the short side direction of the fuse in the second insulating film located on the fuse has a triangular shape.

  In the semiconductor device according to the present invention, the thickness of the second insulating film located on the peripheral region of the fuse is smaller than the thickness of the second insulating film located on the peripheral region of the wiring. preferable.

  In the semiconductor device according to the present invention, it is preferable that the TiN film covers a central portion of the fuse and the width of the TiN film is not less than half of the width in the short side direction of the fuse.

  In the semiconductor device according to the present invention, the third insulating film and the fourth insulating film have moisture resistance. For example, the third insulating film and the fourth insulating film are silicon nitride films. Is preferred.

  The first semiconductor device manufacturing method according to the present invention includes a step (a) of forming a first insulating film on a semiconductor substrate, a TiN film on the surface of the first insulating film, and an Al layer. A step (b) of forming a fuse having a main component and a wiring, and a second insulating film thicker than the fuse on the first insulating film so as to cover the fuse and the wiring. A step (c) of forming, a step (d) of forming a third insulating film on the second insulating film, and etching the third insulating film located on the fuse and its peripheral region. And removing the step (e), and etching the second insulating film located on the fuse and its peripheral region, leaving the second insulating film on the fuse, and the peripheral region of the fuse A step (f) of thinning the second insulating film located above; Forming a fourth insulating film that is thinner than the thickness of the third insulating film on the second insulating film and the third insulating film located on the fuse and its peripheral region (g) In the step (c), the second insulating film is formed thinner than the total thickness of the thickness of the fuse and half of the width in the short side direction of the fuse in the step (c). Thereby, in the step (f), the cross section in the short side direction of the fuse in the second insulating film remaining on the fuse is made triangular.

  In the first method of manufacturing a semiconductor device according to the present invention, in the step (f), the TiN film covers the central portion of the fuse and has a width that is at least half the width in the short side direction of the fuse. It is preferable to leave it in.

  The second method for manufacturing a semiconductor device according to the present invention includes a step (a) of forming a first insulating film on a semiconductor substrate, a TiN film on the surface of the first insulating film, and an Al layer. A step (b) of forming a fuse having a main component and a wiring, and a thickness substantially equal to the thickness of the fuse on the first insulating film so as to cover the fuse and the wiring. A step (c) of forming a second insulating film having HDP-CVD, a step (d) of forming a third insulating film on the second insulating film, and the fuse and its periphery A step (e) of etching and removing the third insulating film located on the region, and on the second insulating film and the third insulating film located on the fuse and its peripheral region. A step (f) of forming a fourth insulating film thinner than the thickness of the third insulating film; In the step (b), the thickness of the fuse is set to be not less than half of the width in the short side direction of the fuse, whereby the second position located on the fuse in the step (c). A cross section in the short side direction of the fuse in the insulating film is triangular.

  In the first or second semiconductor device manufacturing method according to the present invention, the third insulating film and the fourth insulating film have moisture resistance, for example, the third insulating film and the fourth insulating film. The insulating film is preferably a silicon nitride film.

  According to the present invention, when the insulating film on the fuse is etched, a part of the insulating film remains on the fuse. Therefore, the TiN film on the fuse surface covers the fuse central part and is half the width in the short side direction of the fuse. It can remain so as to have the above width. For this reason, when the fuse is cut by the laser, the increase in the reflectance of the laser from the fuse can be suppressed to less than half (compared to the case where the TiN film on the fuse surface part is completely left). A decrease in applied energy can be suppressed. Therefore, it is possible to prevent the scattering of the fuse that occurs when the energy necessary for melting and evaporating the fuse is insufficient, thereby reducing the fuse pitch and the chip size.

  Further, according to the present invention, since the cross section in the fuse short side direction of the insulating film (second insulating film) remaining on the fuse has a triangular shape, in other words, on the fuse peripheral portion of the insulating film. Since the thickness is smaller than the thickness of the insulating film on the fuse center, the strength of the insulating film on the periphery of the fuse is lower than when suppressing the increase in laser reflectivity by leaving the insulating film thick on the entire surface of the fuse. Therefore, the energy for cutting the fuse can be reduced.

(First embodiment)
Hereinafter, a semiconductor device and a manufacturing method thereof according to a first embodiment of the present invention will be described with reference to the drawings.

  1-5 is sectional drawing which shows each process of the manufacturing method of the semiconductor device which concerns on 1st Embodiment.

  First, as shown in FIG. 1, after forming an insulating film 1 made of, for example, a silicon oxide film on a semiconductor substrate 10, an adhesion layer 2 made of, for example, Ti and TiN and having a thickness of about 100 nm is formed on the insulating film 1. A metal layer 3 made of Al as a main component and having a thickness of about 500 nm and an antireflection film 4 made of TiN and having a thickness of about 30 nm are sequentially deposited.

  Next, as shown in FIG. 2, the antireflection film 4, the metal layer 3 and the adhesion layer 2 are etched using a photoresist (not shown) as a mask, so that the adhesion layer 2a, the metal layer 3a and the antireflection film are etched. At the same time as forming the fuse 11 composed of the film 4a, after forming the wiring 12 composed of the adhesion layer 2b, the metal layer 3b, and the antireflection film 4b, the above-mentioned photoresist is removed. In the present embodiment, the height b of the fuse 11 is about 630 nm, and the width (width in the short side direction) a of the fuse 11 is about 600 nm.

  Next, as shown in FIG. 3, a silicon oxide film 5 having a thickness of about 750 nm is deposited on the insulating film 1 by HDP (high density plasma) -CVD so as to cover the fuse 11 and the wiring 12. Here, the effect of sputter etching is obtained by depositing the silicon oxide film 5 using the HDP-CVD method. As a result, the height of the silicon oxide film 5 on the fuse 11 is set to a half of the width a of the fuse 11, that is, a / 2 (provided that the deposited film thickness of the silicon oxide film 5 is larger than a / 2 and smaller than b + a / 2). Thereby, as shown in FIG. 3, the silicon oxide film 5 located on the fuse 11 is formed such that the cross section in the short side direction of the fuse 11 includes a triangle having a height d. The height d is about 180 nm by substituting a = 600 nm and b = 630 nm into d = a / 2−c = a / 2− (750 nm−b). C is about 120 nm. Subsequently, a silicon nitride film 6 having a thickness of about 500 nm is deposited on the silicon oxide film 5.

  Next, as shown in FIG. 4, the silicon nitride film 6 and the silicon oxide film 5 are etched using a photoresist (not shown) having an opening in the fuse region as a mask to form the upper opening 7 in the fuse. Remove the photoresist. In this embodiment, the etching amount of the silicon oxide film 5 is set to a range of about 30 to 150 nm. Thus, the silicon oxide film 5a is formed on the fuse 11 so that the cross section in the short side direction of the fuse 11 includes a triangle (a height of about 150 to 270 nm and a base length of about 300 to 540 nm). it can. Therefore, even after the above-described etching, the antireflection film 4b, that is, the TiN film on the surface of the fuse 11 can be left so as to cover the central portion of the fuse 11 and have a width that is more than half the width a of the fuse 11. .

  In the present embodiment, when the height of the silicon oxide film 5a on the fuse 11 (the height of the triangle described above) exceeds 270 nm, Al constituting the fuse 11 is melted and evaporated when the fuse 11 is cut by a laser. Since the path to be shielded is blocked by the silicon oxide film 5a on the fuse 11, a disconnection failure occurs. If the height of the silicon oxide film 5a on the fuse 11 is less than 150 nm, the width of the TiN film constituting the antireflection film 4b on the surface of the fuse 11 is less than half of the width a of the fuse 11. When cutting 11 with a laser, the increase in the reflectance of the laser from the fuse 11 becomes remarkable, and the fuse 11 is likely to be scattered.

  In the present embodiment, the width a of the fuse 11 is set to 600 nm, but may be set smaller than this. Here, the lower limit of the triangular height of the silicon oxide film 5a necessary for securing half of the width a of the fuse 11 as the width of the antireflection film 4b on the surface of the fuse 11 is approximately 1 / th of the width a of the fuse 11. Therefore, if the width a of the fuse 11 is reduced, the lower limit of the triangular height of the silicon oxide film 5a can be reduced.

  Finally, as shown in FIG. 5, a silicon nitride film 8 having a thickness of about 50 nm is deposited as a protective film for the fuse region on the bottom surface and side wall of the fuse upper opening 7 and on the silicon nitride film 6.

  As described above, according to the present embodiment, when the silicon nitride film 6 and the silicon oxide film 5 on the fuse are etched, a part of the silicon oxide film 5 (silicon oxide film 5a) remains on the fuse 11. Therefore, the TiN film serving as the antireflection film 4a on the surface portion of the fuse 11 can be left so as to cover the center portion of the fuse 11 and to have a width that is more than half of the width in the short side direction of the fuse 11. For this reason, when the fuse 11 is cut by the laser, the increase in the reflectance of the laser from the fuse 11 can be suppressed to half or less (compared to the case where the TiN film on the surface of the fuse 11 is completely left). The decrease in energy applied to the fuse 11 can be suppressed. Accordingly, it is possible to prevent the fuse 11 from being scattered when the energy required to melt and evaporate the fuse 11 is insufficient, thereby reducing the fuse pitch and the chip size.

  Further, according to the present embodiment, since the cross section in the short side direction of the fuse 11 in the silicon oxide film 5a remaining on the fuse 11 has a triangular shape, in other words, on the periphery of the fuse 11 of the silicon oxide film 5a. Since the thickness of the silicon oxide film 5a is smaller than the thickness of the silicon oxide film 5a on the center portion of the fuse 11, the periphery of the fuse 11 is compared with the case where the silicon oxide film 5 is left thick on the entire surface of the fuse 11 to suppress the increase in laser reflectivity. Since the strength of the silicon oxide film 5a on the portion can be lowered, the energy for cutting the fuse 11 can be reduced.

  In this embodiment, the silicon nitride film 6 is formed on the silicon oxide film 5 except on the fuse 11 and its peripheral region. Alternatively, another insulating film having moisture resistance may be formed instead. Good. Further, although the silicon nitride film 8 is formed as a protective film for the fuse region, another insulating film having moisture resistance may be formed instead.

  Hereinafter, the semiconductor device according to the first embodiment of the present invention will be described in more detail with reference to FIGS. 6 and 11 to 13.

  FIG. 6 is a diagram illustrating an example of a cross-sectional configuration of the fuse region of the semiconductor device according to the first embodiment. In the cross-sectional configuration shown in FIG. 6, the width of the fuse 11 (width in the short side direction) is 600 nm, the cross section in the short side direction of the fuse 11 in the silicon oxide film 5a on the fuse 11 is triangular, The antireflection film 4a made of a TiN film is left so as to cover the center portion of the fuse 11 and to have a width that is more than half of the width in the short side direction of the fuse 11. The height (triangular height) t1 of the silicon oxide film 5a on the fuse 11 is about 150 to 270 nm, and the scraping amount (maximum value) t2 of the TiN film to be the antireflection film 4a is about 20 nm.

  FIG. 11 is a diagram illustrating a relationship between the remaining ratio of the TiN film on the fuse (TiN remaining ratio) and the intensity of laser reflection by the fuse (laser reflection intensity) in the semiconductor device according to the first embodiment. Here, the remaining TiN ratio is the ratio of the width (width after etching) of the TiN film to be the antireflection film 4a to the width in the short side direction of the fuse 11. The laser reflection intensity is expressed as a relative value with the intensity when the remaining TiN ratio is 0% being 100%. FIG. 12 is a diagram showing the relationship between the silicon oxide film thickness on the fuse and the disconnection failure rate of the fuse in the semiconductor device according to the first embodiment. FIG. 13 is a diagram showing a relationship between the TiN remaining rate on the fuse and the disconnection failure rate of the fuse in the semiconductor device according to the first embodiment.

  As shown in FIG. 11, when the remaining TiN ratio on the fuse 11 falls below 50%, the laser reflection intensity by the fuse 11 starts to increase. Further, as shown in FIG. 13, when the remaining TiN ratio on the fuse 11 is less than 50%, the fuse 11 is defective in cutting. As shown in FIG. 12, when the thickness of the silicon oxide film 5a on the fuse 11 (triangular height t1) exceeds 270 nm, the fuse 11 is configured when the fuse 11 is cut by a laser. Since the path through which Al melts and evaporates is shielded by the silicon oxide film 5a on the fuse 11, a cutting failure occurs. Based on the relationships shown in FIGS. 11 to 13, in the present embodiment, the range of the triangular height t1 of the silicon oxide film 5a is set to about 150 to 270 nm. In the present embodiment, the width a of the fuse 11 is set to 600 nm, but may be set smaller than this. Here, the lower limit of the triangular height of the silicon oxide film 5a necessary for securing half of the width a of the fuse 11 as the width of the antireflection film 4b on the surface of the fuse 11 is approximately 1 / th of the width a of the fuse 11. Therefore, if the width a of the fuse 11 is reduced, the lower limit of the triangular height of the silicon oxide film 5a can be reduced.

  According to the configuration of the semiconductor device of this embodiment described above, when the fuse 11 is cut by the laser, the increase in the reflectance of the laser from the fuse 11 is less than half (the TiN film on the surface of the fuse 11 remains completely). Compared to the case where the energy is applied), the decrease in energy applied to the fuse 11 can be suppressed. Accordingly, it is possible to prevent the fuse 11 from being scattered when the energy required to melt and evaporate the fuse 11 is insufficient.

  In the configuration of the semiconductor device of the present embodiment shown in FIG. 6, the length of the base of the triangle, which is the cross-sectional shape in the short side direction of the fuse 11, in the silicon oxide film 5 a on the fuse 11 is set in the short side direction of the fuse 11. A part of the antireflection film 4a made of the TiN film on the fuse 11 was cut off by making it smaller than the width. However, instead of this, like the other configuration example of the semiconductor device of the present embodiment shown in FIG. 7, the bottom of the triangle which is the cross-sectional shape in the short side direction of the fuse 11 in the silicon oxide film 5 a on the fuse 11. The length may be approximately the same as the width in the short side direction of the fuse 11 so that the antireflection film 4a made of a TiN film on the fuse 11 is not cut.

(Modification of the first embodiment)
Hereinafter, a semiconductor device and a manufacturing method thereof according to a modification of the first embodiment of the present invention will be described with reference to the drawings.

  8 to 10 are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to a modification of the first embodiment.

  First, as in the first embodiment, as shown in FIG. 1, after an insulating film 1 made of, for example, a silicon oxide film is formed on a semiconductor substrate 10, it is made of, for example, Ti and TiN on the insulating film 1. An adhesion layer 2 having a thickness of about 100 nm, a metal layer 3 having a thickness of about 500 nm mainly composed of Al, and an antireflection film 4 made of TiN and having a thickness of about 30 nm are sequentially deposited.

  Next, as shown in FIG. 2, the antireflection film 4, the metal layer 3 and the adhesion layer 2 are etched using a photoresist (not shown) as a mask, so that the adhesion layer 2a, the metal layer 3a and the antireflection film are etched. At the same time as forming the fuse 11 composed of the film 4a, after forming the wiring 12 composed of the adhesion layer 2b, the metal layer 3b, and the antireflection film 4b, the above-mentioned photoresist is removed. In the present embodiment, the height b of the fuse 11 is about 630 nm, and the width (width in the short side) a of the fuse 11 is about 400 nm.

  Next, as shown in FIG. 8, on the insulating film 1 so as to cover the fuse 11 and the wiring 12, silicon having a thickness (about 630 nm) approximately the same as the height b of the fuse 11 is formed by HDP-CVD. An oxide film 5 is deposited. Here, the effect of sputter etching is obtained by depositing the silicon oxide film 5 using the HDP-CVD method. As a result, the height of the silicon oxide film 5a on the fuse 11 is set to half the width a of the fuse 11, that is, a / 2 can be set. Thus, as shown in FIG. 8, the cross section in the short side direction of the fuse 11 in the silicon oxide film 5a located on the fuse 11 is a triangle having a height d. The height d is about 200 nm by substituting a = 400 nm for d = a / 2. Subsequently, a silicon nitride film 6 of about 500 nm is deposited on the silicon oxide film 5.

  Next, as shown in FIG. 9, the silicon nitride film 6 is etched to form a fuse upper opening 7 using a photoresist (not shown) having an opening in the fuse region as a mask, and then the photoresist is removed. . At this time, the cross section in the short side direction of the fuse 11 in the silicon oxide film 5a remaining on the fuse 11 has a triangle having a height of about 200 nm and a base of about 400 nm. Therefore, even after the above-described etching, the antireflection film 4 b on the surface of the fuse 11, that is, the TiN film, has a width approximately equal to the width a of the fuse 11.

  Finally, as shown in FIG. 10, a silicon nitride film 8 having a thickness of about 50 nm is deposited as a protective film for the fuse region on the bottom and side walls of the upper opening 7 and on the silicon nitride film 6.

  As described above, according to this modification, when the silicon nitride film 6 on the fuse is etched, a part of the silicon oxide film 5 (silicon oxide film 5a) remains on the fuse 11, The TiN film serving as the antireflection film 4 a on the surface of the fuse 11 can be left so as to have the same width as the width in the short side direction of the fuse 11. For this reason, when the fuse 11 is cut by the laser, an increase in the reflectance of the laser from the fuse 11 can be reliably suppressed, so that a decrease in energy applied to the fuse 11 can be suppressed. Accordingly, it is possible to prevent the fuse 11 from being scattered when the energy required to melt and evaporate the fuse 11 is insufficient, thereby reducing the fuse pitch and the chip size.

  Further, according to the present modification, the cross section in the short side direction of the fuse 11 in the silicon oxide film 5a remaining on the fuse 11 has a triangular shape. In other words, on the periphery of the fuse 11 of the silicon oxide film 5a. Since the thickness of the silicon oxide film 5a is smaller than the thickness of the silicon oxide film 5a on the center portion of the fuse 11, the periphery of the fuse 11 is compared with the case where the silicon oxide film 5 is left thick on the entire surface of the fuse 11 to suppress the increase in laser reflectivity. Since the strength of the silicon oxide film 5a on the portion can be lowered, the energy for cutting the fuse 11 can be reduced.

  In this modification, when the height of the silicon oxide film 5a on the fuse 11 (the height of the above-described triangle) exceeds 270 nm, Al constituting the fuse 11 is melted and evaporated when the fuse 11 is cut by a laser. Since the path to be shielded is blocked by the silicon oxide film 5a on the fuse 11, a disconnection failure occurs.

  In this modification, the width a of the fuse 11 is set to 400 nm, but may be set smaller than this. Specifically, as long as the thickness (height b) of the fuse 11 is not less than half of the width a of the fuse 11, the size of the width a of the fuse 11 is not particularly limited.

  In the present modification, the silicon nitride film 6 is formed on the silicon oxide film 5 except on the fuse 11 and its peripheral region. Alternatively, another insulating film having moisture resistance may be formed instead. Good. Further, although the silicon nitride film 8 is formed as a protective film for the fuse region, another insulating film having moisture resistance may be formed instead.

  INDUSTRIAL APPLICABILITY The present invention is useful as a semiconductor device capable of reducing the chip size by suppressing the scattering of the fuse when the fuse is cut in an integrated circuit equipped with a laser fuse element, and a method for manufacturing the same.

FIG. 1 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a step of the method of manufacturing the semiconductor device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a step of the method of manufacturing the semiconductor device according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view showing a step of the method of manufacturing a semiconductor device according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing a step of the method of manufacturing the semiconductor device according to the first embodiment of the present invention. FIG. 6 is a diagram showing an example of a cross-sectional configuration of the fuse region of the semiconductor device according to the first embodiment of the present invention. FIG. 7 is a view showing another example of the cross-sectional configuration of the fuse region of the semiconductor device according to the first embodiment of the present invention. FIG. 8 is a cross-sectional view showing one step of a method for manufacturing a semiconductor device according to a modification of the first embodiment of the present invention. FIG. 9 is a cross-sectional view showing one step of a method for manufacturing a semiconductor device according to a modification of the first embodiment of the present invention. FIG. 10 is a cross-sectional view showing one step of a method for manufacturing a semiconductor device according to a modification of the first embodiment of the present invention. FIG. 11 is a diagram showing the relationship between the remaining ratio of the TiN film on the fuse (TiN remaining ratio) and the intensity of laser reflection by the fuse (laser reflection intensity) in the semiconductor device according to the first embodiment of the present invention. FIG. 12 is a diagram showing the relationship between the silicon oxide film thickness on the fuse and the disconnection failure rate of the fuse in the semiconductor device according to the first embodiment of the present invention. FIG. 13 is a diagram showing the relationship between the remaining TiN rate on the fuse and the disconnection failure rate of the fuse in the semiconductor device according to the first embodiment of the present invention. FIG. 14 is a cross-sectional view showing one step of a conventional method for manufacturing a semiconductor device. FIG. 15 is a cross-sectional view showing one step of a conventional method for manufacturing a semiconductor device. FIG. 16 is a cross-sectional view showing one step of a conventional method for manufacturing a semiconductor device. FIG. 17 is a cross-sectional view showing one step of a conventional method for manufacturing a semiconductor device. FIG. 18 is a cross-sectional view showing one step of a conventional method for manufacturing a semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating film 2, 2a, 2b Adhesion layer 3, 3a, 3b Metal layer 4, 4a, 4b Antireflection film 5, 5a Silicon oxide film 6 Silicon nitride film 7 Opening part on fuse
8 Silicon nitride film 10 Semiconductor substrate 11 Fuse 12 Wiring

Claims (10)

A first insulating film formed on the semiconductor substrate;
A fuse formed on the first insulating film, having a TiN film on its surface and mainly comprising Al;
A wiring formed on the first insulating film;
A second insulating film formed on the first insulating film so as to cover the fuse and the wiring;
A third insulating film formed on the second insulating film except on the fuse and its peripheral region;
A fourth insulating film formed on the second insulating film and on the third insulating film located on the fuse and its peripheral region,
The semiconductor device according to claim 1, wherein a cross section in the short side direction of the fuse in the second insulating film located on the fuse has a triangular shape. The semiconductor device according to claim 1,
The semiconductor device according to claim 1, wherein a thickness of the second insulating film located on a peripheral region of the fuse is smaller than a thickness of the second insulating film located on a peripheral region of the wiring. The semiconductor device according to claim 1 or 2,
The TiN film covers a central portion of the fuse, and the width of the TiN film is more than half of the width in the short side direction of the fuse. The semiconductor device according to any one of claims 1 to 3,
The semiconductor device, wherein the third insulating film and the fourth insulating film have moisture resistance. The semiconductor device according to claim 4,
The semiconductor device, wherein the third insulating film and the fourth insulating film are silicon nitride films. Forming a first insulating film on the semiconductor substrate (a);
A step (b) of forming a fuse having a TiN film on the surface and having Al as a main component and a wiring on the first insulating film;
Forming a second insulating film thicker than the thickness of the fuse on the first insulating film so as to cover the fuse and the wiring; and
Forming a third insulating film on the second insulating film (d);
Etching and removing the third insulating film located on the fuse and its peripheral region; and
Etching the second insulating film located on the fuse and its peripheral region, and leaving the second insulating film on the fuse, the second insulation located on the peripheral region of the fuse A step (f) of thinning the membrane;
Forming a fourth insulating film that is thinner than the thickness of the third insulating film on the second insulating film and the third insulating film located on the fuse and its peripheral region (g) )
In the step (c), using the HDP-CVD method, the second insulating film is formed thinner than the total thickness of the thickness of the fuse and half of the width in the short side direction of the fuse, In the step (f), a method of manufacturing a semiconductor device, wherein a cross section in a short side direction of the fuse in the second insulating film remaining on the fuse is formed into a triangular shape. In the manufacturing method of the semiconductor device according to claim 6,
In the step (f), the TiN film is left so as to cover the center portion of the fuse and to have a width of half or more of the width in the short side direction of the fuse. Forming a first insulating film on the semiconductor substrate (a);
A step (b) of forming a fuse having a TiN film on the surface and having Al as a main component and a wiring on the first insulating film;
Forming a second insulating film having a thickness substantially equal to the thickness of the fuse using the HDP-CVD method on the first insulating film so as to cover the fuse and the wiring (c) )When,
Forming a third insulating film on the second insulating film (d);
Etching and removing the third insulating film located on the fuse and its peripheral region; and
Forming a fourth insulating film thinner than the third insulating film on the second insulating film and the third insulating film located on the fuse and the peripheral region thereof (f) )
In the step (b), the thickness of the fuse is set to more than half of the width in the short side direction of the fuse, whereby the second insulating film located on the fuse in the step (c). A method of manufacturing a semiconductor device, characterized in that the cross section in the short side direction of the fuse in FIG. In the manufacturing method of the semiconductor device according to any one of claims 6 to 8,
The method for manufacturing a semiconductor device, wherein the third insulating film and the fourth insulating film have moisture resistance. In the manufacturing method of the semiconductor device according to claim 9,
The method for manufacturing a semiconductor device, wherein the third insulating film and the fourth insulating film are silicon nitride films.

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