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Patent Issued for Semiconductor Device Comprising Electromigration Prevention Film and Manufacturing Method

June 25, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- A patent by the inventors Kouno, Ichiro (Hamura, JP); Wakabayashi, Takeshi (Sayama, JP); Mihara, Ichiro (Tachikawa, JP), filed on January 22, 2008, was published online on June 10, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8749065 is assigned to Tera Probe, Inc. (Kanagawa, JP).

The following quote was obtained by the news editors from the background information supplied by the inventors: "This invention relates to a semiconductor device comprising an electromigration prevention film and a manufacturing method thereof.

"A semiconductor device called a chip size package (CSP) has been described in Jpn. Pat. Appln. KOKAI Publication No. 2004-207306. This semiconductor device comprises a semiconductor substrate having a plurality of connection pads provided on its upper surface. On the upper surface of an insulating film provided on the semiconductor substrate, a plurality of wiring lines are provided so that they are electrically connected to the respective connection pads. Columnar electrodes are provided on the respective upper surfaces of connection pad portions of these wiring lines. A sealing film is provided on the upper surfaces of the wiring lines and the insulating film so that the upper surface of this sealing film is flush with the upper surfaces of the columnar electrodes. Solder balls are respectively provided on the upper surfaces of the columnar electrodes.

"In the conventional semiconductor device described above, the sealing film directly covering the wiring lines is formed of an epoxy resin, so that there is such a problem that metal (copper) ions in the wiring lines diffuse into the sealing film due to the generation of electromigration, which is one factor of a short circuit caused between the wiring lines.

"Furthermore, an epoxy resin in which fillers made of, for example, silica may be used as the material of the sealing film. In such a semiconductor device, the wiring lines may be mechanically damaged by the fillers. In preventing the breaking of the wiring lines due to the mechanical damage, there is a problem of a limit in the miniaturization of the wiring lines."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "It is therefore an object of this invention to provide a semiconductor device and a manufacturing method thereof which can prevent a short circuit caused between wiring lines by electromigration and which makes it possible to prevent the wiring lines from being easily mechanically damaged by fillers even if a resin containing the fillers is used as the material of a sealing film.

"A semiconductor device according to a first aspect of the present invention comprising:

"a semiconductor substrate;

"a plurality of wiring lines which are provided on one side of the semiconductor substrate and which have connection pad portions;

"a plurality of columnar electrodes respectively provided on the connection pad portions of the wiring lines, each of the columnar electrodes including an outer peripheral surface and a top surface;

"an electromigration prevention film provided on at least the surfaces of the wiring lines; and

"a sealing film provided around the outer periphery surfaces of the columnar electrodes.

"A semiconductor device according to a second aspect of the present invention claim comprising:

"a semiconductor substrate;

"a plurality of wiring lines provided on an upper side of the semiconductor substrate;

"an inorganic insulating film which is provided on the surfaces of the wiring lines and which has openings in parts corresponding to connection pad portions of the wiring lines;

"an overcoat film made of an organic resin which is provided on the upper surface of the inorganic insulating film and the upper side of the semiconductor substrate and which has openings in parts corresponding to the connection pad portions of the wiring lines; and

"a plurality of columnar electrodes which are provided in the openings of the inorganic insulating film and in and above the openings of the overcoat film and which are electrically connected to the connection pad portions of the wiring lines.

"A manufacturing method of an invention according to a third aspect of the present invention comprising:

"forming a plurality of wiring lines on an upper side of a semiconductor substrate;

"forming a plurality of columnar electrodes on connection pad portions of the wiring lines;

"forming an electromigration prevention film on surfaces of the wiring lines, on surfaces of the columnar electrodes and on the upper side of the semiconductor substrate;

"forming a sealing film on the electromigration prevention film; and

"grinding an upper surface side of the sealing film to expose upper surfaces of the columnar electrodes.

"A manufacturing method of an invention according to a fourth aspect of the present invention comprising:

"forming a plurality of wiring lines on an upper side of a semiconductor substrate;

"forming a plurality of columnar electrodes on connection pad portions of the wiring lines;

"forming an electromigration prevention film on surfaces of the wiring lines, on surfaces of the columnar electrodes and on the upper side of the semiconductor substrate;

"removing the electromigration prevention film formed on the surfaces of upper portions of the columnar electrodes;

"forming a sealing film on the electromigration prevention film and the columnar electrodes; and

"grinding an upper surface side of the sealing film to expose upper surfaces of the columnar electrodes.

"A semiconductor device manufacturing method according to a fifth aspect of the present invention comprising:

"forming a plurality of wiring lines on an upper side of semiconductor substrate;

"forming, on surfaces of the wiring lines, an inorganic insulating film having openings in parts corresponding to connection pad portions of the wiring lines;

"forming, on the upper side of the semiconductor substrate and on the inorganic insulating film, an overcoat film made of an organic resin having openings in parts corresponding to the connection pad portions of the wiring lines; and

"forming, by electrolytic plating, columnar electrodes in the openings of the inorganic insulating film and in and above the openings of the overcoat film.

"According to the present inventions, the electromigration prevention film is provided on at least the surfaces of the wiring lines, and it is therefore possible to prevent a short circuit caused between the wiring lines by electromigration. Moreover, the electromigration prevention film functions as a protective film, which makes it possible to prevent the wiring lines from being easily mechanically damaged by fillers even if a resin containing the fillers is used as the material of the sealing film.

"Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter."

URL and more information on this patent, see: Kouno, Ichiro; Wakabayashi, Takeshi; Mihara, Ichiro. Semiconductor Device Comprising Electromigration Prevention Film and Manufacturing Method. U.S. Patent Number 8749065, filed January 22, 2008, and published online on June 10, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8749065.PN.&OS=PN/8749065RS=PN/8749065

Keywords for this news article include: Electronics, Semiconductor, Tera Probe Inc.

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Source: Electronics Newsweekly


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