JP2008053287A - Semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device in a chip size package form having excellent moisture-resistance, and a manufacturing method for the semiconductor device. <P>SOLUTION: The semiconductor device has a semiconductor substrate 11, an image sensing element 14 formed on one surface of the semiconductor substrate 11 and electrode pads 21 formed around the image sensing element on one surface. The semiconductor device further has through-electrodes 22 formed to through-holes 22a penetrated to one surface and the other surface on the reverse side to one surface, and electrically connected to the electrode pads 21; and a transparent sealing member 17 being joined so as to coat one surface and sealing the image sensing element 14 and the electrode pads 21. The transparent sealing member 17 is joined with the semiconductor substrate 11 by a joining member 31, and surfaces 31a exposed to the outside in the joining member 31 are composed of at least a moisture-resistant material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor element having a small and thin package form, and more particularly, to a semiconductor device having a back surface through-hole wiring electrode structure and a method for manufacturing the semiconductor device.

  In recent years, along with miniaturization, high speed, and high performance of electronic devices, semiconductor devices are also required to be small and high speed. In order to realize such miniaturization and high speed, a chip size package (hereinafter referred to as CSP) in which the size of the semiconductor device including the package is the same size as the semiconductor chip has been proposed.

  As a manufacturing method of CSP, first, a photoelectric conversion part such as a photodiode is formed by implanting impurity ions on the surface of a semiconductor substrate, and a thermal oxide film, a BPSG film (or silicon oxide film) or the like is formed on the semiconductor substrate. Form. On the semiconductor substrate, a rectangular imaging element is formed in a plan view, and a plurality of electrode pads are formed around the imaging element. A through-hole is formed below the electrode pad in the semiconductor substrate so as to penetrate the back side of the semiconductor substrate (opposite to the side where the image sensor is formed). The through-hole has a substantially columnar through-electrode. Is formed. The through electrode is configured such that one end thereof is electrically connected to the electrode pad, and the other end is connected to the wiring portion and the mounting terminal. As described above, since the CSP does not require a space for connecting the electrode lead or the conductor wiring using the bonding wire to the electrode pad, the semiconductor element can be miniaturized. After the CSP element chips are arranged and formed on the silicon wafer, the CSP element chips are taken out along the scribe lines formed between the element chips. As a configuration of a conventional CSP, for example, there is one shown in the following patent document.

JP 2006-1000043 A JP 2004-207461 A

  By the way, the conventional CSP seals an image pickup element, an electrode pad, and the like by attaching an inorganic transparent material such as glass to the surface of a semiconductor substrate with an adhesive applied on a live line. . And, when performing dicing on the scribe line of the semiconductor substrate, moisture enters from between the adhesive on the end face of the separated element chip and the silicon substrate, and adheres to the internal imaging device or electrode pad. There is. Moreover, even after dicing, moisture may permeate into the CSP from between the adhesive and the silicon substrate depending on the humidity. Then, if the metal material corrodes due to the intrusion of moisture, a half-break or disconnection occurs, the image sensor does not operate normally, a normal image signal cannot be obtained, and image unevenness or display failure occurs. There was room for improvement in some respects. In addition, there is room for improvement in that the adhesive expands in accordance with the humidity to cause the element chip and the chip package member to be separated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a semiconductor device having a chip size package having excellent moisture resistance and a method for manufacturing the semiconductor device.

The above object of the present invention is achieved by the following configurations.
(1) A semiconductor substrate, an image sensor formed on one surface of the semiconductor substrate, an electrode pad formed around the image sensor on the one surface, the one surface, and the one Formed in a through-hole that penetrates the other surface opposite to the surface, and is connected to the through-electrode electrically connected to the electrode pad so as to cover the one surface. A semiconductor device comprising a transparent sealing member for sealing an electrode pad, wherein the transparent sealing member is bonded to the semiconductor substrate by a bonding member, and a surface exposed to the outside of the bonding member is made of at least a moisture-resistant material. A semiconductor device characterized by the above.
(2) The semiconductor device according to (1), wherein the moisture-resistant material is a silicon nitride film.
(3) The semiconductor device according to (1) or (2), wherein the bonding member includes at least plasma silicon nitride.
(4) The bonding member is formed by patterning a silicon nitride film formed on one surface of a semiconductor substrate. (1) In any one of the above (1) to (3), Semiconductor device.
(5) Any one of (1) to (4), wherein a transparent film is formed on the second insulating film, and an edge portion of the transparent film is not covered with the bonding member. The semiconductor device described in one.
(6) A semiconductor substrate formed by dicing a semiconductor wafer along a scribe line, an image sensor formed on one surface of the semiconductor substrate, and around the image sensor on the one surface A through electrode formed in a through-hole penetrating the formed electrode pad, the one surface, and the other surface opposite to the one surface, and electrically connected to the electrode pad; A method of manufacturing a semiconductor device comprising: a transparent sealing member that is bonded so as to cover one surface and seals the imaging element and the electrode pad, wherein a film constituting the bonding member is formed on the transparent sealing member. And forming a pattern on the film so as to remove a portion bonded to the scribe line, and then bonding the bonding member to the semiconductor substrate side.

  In the semiconductor device of the present invention, the transparent sealing member covering one surface of the semiconductor substrate is joined to the semiconductor substrate by a joining member instead of the conventional organic adhesive. In addition, since the surface exposed to the outside of the bonding member is made of at least silicon nitride, it is possible to prevent moisture from entering the semiconductor device by the bonding member after the dicing process. For this reason, it can prevent that metal materials, such as an image pick-up element and an electrode pad, corrode with moisture. Therefore, according to the present invention, it is possible to provide a semiconductor device with less defects such as image unevenness and display failure by improving moisture resistance.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device of a chip size package form excellent in moisture resistance and a semiconductor device can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall cross-sectional view showing a configuration of a semiconductor device according to the present invention. FIG. 2 is a diagram illustrating the configuration of the semiconductor device in plan view. FIG. 3 is an enlarged cross-sectional view of a main part of the semiconductor device.

  The semiconductor device 10 of this embodiment includes a semiconductor substrate 11 made of silicon or the like. In this embodiment, after a semiconductor device having a plurality of CSP configurations is arranged on a silicon wafer constituting the semiconductor substrate 11 and then formed along a lattice-like scribe line provided between the semiconductor devices. By dicing, the semiconductor device is separated into a rectangular shape in plan view. FIG. 1 shows a configuration of a single semiconductor device after dicing.

An image sensor 14 is formed on the surface of the semiconductor substrate 11. A thermal oxide film 12 such as a field oxide film is formed in a region excluding the region where the image sensor 14 is formed. Further, an insulating film such as a BPSG film or a silicon oxide film (SiO ₂ ) (hereinafter referred to as the first insulating film 13 in the embodiment according to the present invention) is formed on the upper surface of the semiconductor substrate 11.

  For example, a CCD type image sensor or a CMOS type image sensor can be used as the image sensor 14.

  A plurality of electrode pads 21 for inputting / outputting signals to / from the image sensor 14 are formed on the first insulating film 13 in a plan view of FIG. The electrode pad 21 is made of aluminum, for example.

  A through-hole 22a is formed below the electrode pad 21 in the semiconductor substrate 11 so as to penetrate from one surface on the side where the electrode pad 21 is formed to the other surface opposite to the one surface. A substantially columnar through electrode 22 is formed in the through hole 22a. The through electrode 22 has one end electrically connected to the electrode pad 21, and the other end electrically connected to the back electrode 23 formed on the other surface of the semiconductor substrate 11. . The back electrode 23 is formed with an electrode terminal 24 for electrical connection with an external terminal. Although not shown in FIG. 1, an insulating film 26 is formed around the through electrode 22 as described later.

  On the first insulating film 13, a metal wiring layer (not shown) having a single layer or a multilayer structure is formed. A predetermined metal terminal formed on the metal wiring layer is electrically connected to the image sensor 14 and the electrode pad 21.

  On the first insulating film 13, a second insulating film 15 such as a plasma nitride film covers the entire surface of the first insulating film 13 in order to protect the imaging element 14, the electrode pad 21, and the metal wiring layer. It is formed to cover.

  Further, an organic transparent film 16 that can transmit light incident on the image sensor 14 from the outside of the semiconductor device 10 is formed on the second insulating film 15.

  The semiconductor device 10 of the present embodiment has a configuration in which a transparent sealing member 17 made of a light-transmitting inorganic transparent material is bonded to the periphery of the semiconductor substrate 11 by a bonding member 31.

  As shown in FIG. 3, the bonding member 31 is formed in a frame shape so as to straddle the boundary portion between the semiconductor substrate 11 and the edge of the second insulating film 15 and to surround the periphery in a plan view of the semiconductor substrate 11. ing. By bonding the semiconductor substrate 11 and the transparent seal member 31 with the bonding member 31, the imaging element 14 and the electrode pad 21 are sealed from the external atmosphere.

  As shown in FIG. 3, an insulating film 26 is formed on the inner surface of the through hole 22 a and the lower surface of the semiconductor substrate 11 (the surface opposite to the side on which the image sensor 14 is formed). The semiconductor substrate 11 and the through electrode 22 are electrically insulated by the insulating film 26.

  In the semiconductor device 10, the transparent seal member 17 covering one surface of the semiconductor substrate 11 is bonded to the semiconductor substrate 11 by a bonding member 31 instead of a conventional organic adhesive. Further, since the surface 31a exposed to the outside of the bonding member 31 is made of at least silicon nitride, it is possible to prevent moisture from entering the semiconductor device 10 by the bonding member 31 after the dicing process. For this reason, it can prevent that metal materials, such as the image pick-up element 14 and the electrode pad 21, are corroded by a water | moisture content. Therefore, the semiconductor device 10 of the present embodiment can obtain an effect that there are few problems such as image unevenness and display defects by improving the moisture resistance.

  In the present embodiment, a surface (a left side surface in FIG. 3) 31a exposed to the outside of the bonding member 31 is made of at least silicon nitride. If the surface 31a exposed to the outside is silicon nitride, the joining member 31 can be configured such that all or part thereof is formed of silicon nitride. For example, when the bonding member 31 is formed of a material other than silicon nitride, after dicing, only the surface 31a exposed to the outside may be processed to be silicon nitride. Note that it is preferable that the bonding member 31 be formed of plasma silicon nitride (P-SiN) because it is most excellent in moisture resistance.

  As shown in FIG. 3, the semiconductor device 10 of the present embodiment has a configuration in which the edge of the transparent film 16 on the second insulating film 15 is not covered with the bonding member 31. In this way, after the device is manufactured, since the organic material constituting the transparent film 16 does not interfere with the transparent film 16, the transparent film 16 is cracked by the close contact with the bonding member 31. It becomes a piece, and it can be prevented that the semiconductor device 10 adheres to the image pickup element 14, the electrode pad 21, and the metal wiring portion to cause a defect.

  In the present embodiment, the bonding member 31 is used for separating the semiconductor device 10 in the dicing process after the imaging element 14, the electrode pad 21, and other metal wiring portions and the transparent film 16 are formed on the silicon wear. A plasma silicon nitride (P-SiN) film is formed on the formed lattice-shaped scribe line by setting the layer serving as the bonding material 31 to an atmosphere of 200 ° C. or lower by atmospheric pressure plasma CVD, and using a photolithography process or the like. Thus, a pattern can be formed.

Next, another manufacturing procedure of the joining member will be described.
The joining member is not limited to the method of forming the laminated member on the semiconductor substrate 11 side as in the above embodiment, but is formed in advance on the transparent seal member 17 side, and then the transparent seal member 17 is joined on the semiconductor substrate 11 side. May be. At this time, a film to be the bonding material 31 is formed on the bonding side surface of the transparent seal member 17 (the lower surface in FIG. 3), and the film other than the portion located on the scribe line is removed by a photolithography process. A pattern is formed. Then, the transparent seal member 17 on which the bonding member 31 is formed is bonded to the semiconductor substrate 11 on which necessary optical elements such as the imaging element 14 and the electrode pad 21 are formed, and each semiconductor is diced along the scribe line. You may separate for every apparatus.

  In addition, this invention is not limited to embodiment mentioned above, A suitable deformation | transformation, improvement, etc. are possible. The configuration of the semiconductor device of the above embodiment may be, for example, the configuration shown in FIGS. In the embodiment described below, members having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawings, and the description thereof is simplified or omitted.

  In the configuration of the semiconductor device of FIG. 4, a guide member 34 is formed on the second insulating film 15, and the adjacent support material 32 formed on the second insulating film 15 using the guide member 34 as a guide. Is formed. Further, air may exist between the color filter and microlens layer and the transparent seal member 17.

  In the configuration of the semiconductor device of FIG. 5, the second insulating film 15 is formed of a plasma nitride film, the second insulating film 15 is used as a stopper, a transparent seal member 17 is mounted, diced and taken out as a CSP. Yes.

1 is an overall cross-sectional view showing a configuration of a semiconductor device according to the present invention. It is a figure explaining the structure of the semiconductor device in planar view. It is a principal part expanded sectional view of a semiconductor device. It is sectional drawing which shows the modification of a structure of the semiconductor device concerning this invention. It is sectional drawing which shows the modification of a structure of the semiconductor device concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor device 11 Semiconductor substrate 13 1st insulating film 14 Image pick-up element 15 2nd insulating film 16 Transparent film 17 Transparent sealing member 21 Electrode pad 22 Through-electrode 31 Joining member

Claims (6)

A semiconductor substrate;
An image sensor formed on one surface of the semiconductor substrate;
An electrode pad formed around the image sensor on the one surface;
A through electrode formed in a through hole penetrating the one surface and the other surface opposite to the one surface, and electrically connected to the electrode pad;
A semiconductor device comprising a transparent sealing member that is bonded so as to cover the one surface and seals the imaging element and the electrode pad,
The semiconductor device, wherein the transparent sealing member is bonded to the semiconductor substrate by a bonding member, and a surface exposed to the outside of the bonding member is made of at least a moisture-resistant material.   The semiconductor device according to claim 1, wherein the moisture resistant material is a silicon nitride film.   The semiconductor device according to claim 1, wherein the bonding member includes at least plasma silicon nitride.   4. The semiconductor device according to claim 1, wherein the bonding member is formed by patterning a silicon nitride film formed on one surface of a semiconductor substrate. 5.   5. The semiconductor device according to claim 1, wherein a transparent film is formed on the second insulating film, and an edge portion of the transparent film is not covered with the bonding member. 6. . A semiconductor substrate formed by dicing a semiconductor wafer along a scribe line;
An image sensor formed on one surface of the semiconductor substrate;
An electrode pad formed around the image sensor on the one surface;
A through electrode formed in a through hole penetrating the one surface and the other surface opposite to the one surface, and electrically connected to the electrode pad;
A method of manufacturing a semiconductor device comprising: a transparent seal member that is bonded so as to cover the one surface and seals the imaging element and the electrode pad,
Forming a film constituting a bonding member on the transparent seal member, patterning the film so as to remove a portion bonded to the scribe line, and then bonding the bonding member to the semiconductor substrate side; A method of manufacturing a semiconductor device.

Images