JP2004063756A - Solid-state image sensing device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image sensing device which is connected to a wiring unit through its side when the image sensing device is connected to the case of a camera or the like and is capable of keeping a package design high in flexibility, and to provide a method of manufacturing the same. <P>SOLUTION: The method of manufacturing the image sensing device comprises a first process of forming a plurality of image sensing elements 100 on the front face of a semiconductor substrate, a second process of bonding a light transmitting member 200 to the front of the semiconductor substrate as the transparent member 200 is confronted with the light receiving regions of the image sensing elements 100 through a gap, a third process of bonding a support substrate 701 to the rear of the semiconductor substrate, a fourth process of forming a through groove 108 which is equipped with a conductive inner wall and provided to separating regions and their vicinities to separate the image sensing elements on the semiconductor substrate as penetrating through the semiconductor substrate before or after the third process is performed, and a fifth process of separating the bonded body obtained through the above bonding processes into the unit solid state image sensing elements by the separating regions DC as side wall wiring units 109 formed of a part of the through groove whose inner wall is conductive are left. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state imaging device and a manufacturing method thereof, and more particularly to a chip size package (CSP) type solid-state imaging device in which a microlens is integrated on a chip.
[0002]
[Prior art]
A solid-state imaging device including a CCD (Charge Coupled Device) is required to be downsized due to the necessity of application to a mobile phone, a digital camera, and the like.
As one of them, a solid-state imaging device in which a microlens is provided in a light receiving area of a semiconductor chip has been proposed. In such a case, for example, by integrally mounting a solid-state imaging device having a microlens in the light-receiving area so as to have an airtight sealing portion between the light-receiving area of the solid-state imaging device and the microlens, There has been proposed a solid-state imaging device that is miniaturized (Japanese Patent Laid-Open No. 7-202152).
[0003]
According to such a configuration, the mounting area can be reduced, and optical components such as a filter, a lens, and a prism can be bonded to the surface of the hermetic sealing portion, and the light collecting ability of the microlens can be improved. It is possible to reduce the mounting size without causing a decrease.
[0004]
[Problems to be solved by the invention]
However, when mounting such a solid-state imaging device, it is necessary to mount the signal on the support substrate on which the solid-state imaging device is mounted, to make electrical connection and to perform sealing by a method such as bonding, when taking out the signal to the outside. There is. This method has a problem that it takes a lot of time for mounting due to the large number of man-hours.
Further, there is a problem that positioning takes a long time even when the support member or the peripheral circuit board is mounted. In addition, when the wiring length is long, it is difficult to increase the processing circuit speed.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a solid-state imaging device manufacturing method that is easy to manufacture and highly reliable.
It is another object of the present invention to provide a solid-state imaging device that can operate at high speed and has high reliability.
[0005]
[Means for Solving the Problems]
Therefore, the present invention comprises a semiconductor substrate formed with a solid-state image sensor, and a translucent member connected to the semiconductor substrate so as to have a gap facing the light-receiving region of the solid-state image sensor, The semiconductor substrate has a wiring portion on a side surface and is disposed on a support member.
[0006]
According to such a configuration, when connecting to a housing such as a camera, it is possible to connect to the wiring portion on the side surface, and to have flexibility in package design.
[0007]
Desirably, the support member is formed of a semiconductor substrate on which a peripheral circuit is formed, and the semiconductor substrate is connected to a solid-state imaging device via a wiring portion, thereby forming a drive circuit on the back surface side and extracting signals on the side surface. Alternatively, a solid state imaging device that can be connected to a power source and is small and highly reliable can be provided.
[0008]
The solid-state imaging device manufacturing method of the present invention includes a step of forming a plurality of solid-state imaging elements on the surface of the first semiconductor substrate, and the first solid-state imaging device so as to have a gap facing each light receiving region of the solid-state imaging element. A step of bonding the translucent member to the surface of one semiconductor substrate, a step of bonding the first semiconductor substrate to a support substrate, a separation region for separating each solid-state imaging device on the first semiconductor substrate, and In the periphery, a step of forming a through-groove that penetrates the semiconductor substrate and the inner wall is made into a conductor, and a joined body obtained in the joining step is used as a side wall of each solid-state imaging device, and the inner wall is made a conductor. A step of separating each solid-state imaging device in the separation region so as to leave a side wall wiring portion constituted by a part of the through groove.
[0009]
The solid-state imaging device manufacturing method of the present invention includes a separation region for separating each solid-state imaging device on the first semiconductor substrate and a peripheral portion thereof while forming a plurality of solid-state imaging devices on the surface of the first semiconductor substrate. A step of forming a through groove penetrating the first semiconductor substrate and having an inner wall formed as a conductor, and a surface of the first semiconductor substrate so as to have a gap facing each light receiving region of the solid-state imaging device. A step of bonding the translucent member, a step of bonding the first semiconductor substrate to a support substrate, and a bonded body obtained in the bonding step as a side wall of each solid-state imaging device, and the inner wall as a conductor. And a step of separating each solid-state imaging device in the separation region so as to leave a side wall wiring portion constituted by a part of the formed through groove.
[0010]
According to such a configuration, the formation of the wiring pattern on the side surface is performed by positioning at the wafer level and integrated by mounting in a lump, or before the integration, the through groove is formed, and the inside of the through groove is formed. After forming the conductor layer, when separating each solid-state image sensor, the wiring layer is exposed in the divided section by dividing it in the region including this conductor layer. It is possible to form a wiring layer. This wiring is basically composed of a combination of straight lines, and it is only necessary to make a horizontal connection on the front surface or the back surface. If a plurality of through-holes are formed and an insulating layer is interposed in each region, it is possible to form a multilayer wiring on the side surface.
[0011]
Preferably, the step of forming a through groove in which the inner wall is made into a conductor includes a step of forming a through groove, a step of forming an insulating film so as to cover the inner wall of the through groove, and a conductive layer inside the insulating film. Forming a body film.
[0012]
According to such a configuration, since the wiring layer is formed via the insulating film, it can be formed very easily.
[0013]
Desirably, the step of bonding the translucent member includes preparing a translucent substrate having a recess corresponding to the formation region of the solid-state imaging device, and bonding the translucent substrate to the surface of the semiconductor substrate. I am doing so.
[0014]
According to such a configuration, the concave portion can be easily formed so as to have a gap opposite to each light receiving region only by forming the concave portion on the translucent substrate. Is easy.
[0015]
Preferably, prior to the bonding step, the method includes a step of forming a protrusion by selectively removing the surface of the semiconductor substrate so as to surround the light receiving region, and the light receiving region and the light transmitting property are formed by the protrusion. An air gap is formed between the member and the member.
[0016]
According to such a configuration, it is possible to provide a solid-state imaging device with high workability and high reliability simply by mounting with a protrusion (spacer) formed in advance on the surface of the semiconductor substrate.
[0017]
In the bonding step, a gap is formed between the semiconductor substrate and the translucent member via a spacer disposed so as to surround the light receiving region. .
[0018]
According to such a configuration, it is possible to easily provide a highly reliable solid-state imaging device by simply sandwiching the spacer.
[0019]
The step of forming the through groove may include a step of forming a through groove in the semiconductor substrate and a step of forming a conductor layer in the through groove by a vacuum screen printing method.
[0020]
The step of forming the through groove may include a step of forming a through groove in the semiconductor substrate and a step of forming a conductor layer in the through groove by a vacuum suction method.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
(First embodiment)
This solid-state imaging device has a solid-state imaging comprising a silicon substrate 101 as a semiconductor substrate on which a solid-state imaging device 102 is formed, as shown in a sectional view in FIG. A glass substrate 201 as a translucent member is bonded to the element substrate surface via a spacer 203S so as to have a gap C corresponding to the light receiving region of the silicon substrate 101, and the back side of the silicon substrate 101 is reinforced. A plate 701 is formed, and a wiring pattern 118 formed on the side wall of the silicon substrate 101 is formed on the side surface of the solid-state image pickup device substrate to form a side wall wiring 108. Here, reference numeral 109 denotes a silicon oxide film (insulating film).
[0023]
If necessary, it is also possible to connect to the outside as it is on the side surface, and the pad 113 and the bump 114 are formed as external extraction terminals formed on the back surface of the solid-state imaging device substrate, An external connection is made. Here, as shown in FIG. 4D, it is connected to the peripheral circuit board 901 through the anisotropic conductive film 115. Here, the spacer 203S has a height of 10 to 500 μm, preferably 80 to 120 μm. In addition to this, diffusion bonding using ultrasonic waves, solder bonding, and eutectic bonding by thermocompression bonding are also effective as this connection method.
[0024]
Here, as shown in the enlarged cross-sectional view of the main part of the solid-state image pickup device substrate 100, the solid-state image pickup devices are arranged on the surface, and the RGB color filter 46 and the micro lens 50 are formed. A silicon substrate 101 is used. Here, the through hole H does not appear in this cross section, but is formed so as to be connected to the charge transfer electrode 32.
[0025]
In this solid-state imaging device 100, a channel stopper 28 is formed in a p-well 101b formed on the surface of an n-type silicon substrate 101a, and a photodiode 14 and a charge transfer device 33 are formed with the channel stopper interposed therebetween. It will be. Here, the n-type impurity region 14b is formed in the p + channel region 14a, and the photodiode 14 is formed. In addition, a vertical charge transfer channel 20 made of an n-type impurity region having a depth of about 0.3 μm is formed in the p + channel region 14a, and the gate insulating film 30 made of a silicon oxide film is formed thereon. A vertical charge transfer electrode 32 made of a polycrystalline silicon layer is formed to constitute a charge transfer element 33. A read gate channel 26 formed of a p-type impurity region is formed between the vertical charge transfer channel 20 and the photodiode 14 on the side from which signal charges are read out. A through hole H (not shown in FIG. 1B) is formed so as to connect to the vertical charge transfer electrode 32.
[0026]
The n-type impurity region 14b is exposed along the readout gate channel 26 on the surface of the silicon substrate 101, and the signal charge generated in the photodiode 14 is temporarily accumulated in the n-type impurity region 14b. The data is read out through the read gate channel 26.
[0027]
On the other hand, a channel stopper 28 made of a p + -type impurity region exists between the vertical charge transfer channel 20 and the other photodiodes 14, whereby the photodiodes 14 and the vertical charge transfer channels 20 are electrically separated. In addition, the vertical charge transfer channels 20 are separated from each other so as not to contact each other.
[0028]
Further, the vertical charge transfer electrode 32 is formed so as to cover the readout gate channel 26, expose the n-type impurity region 14a, and expose a part of the channel stopper 28. Signal charges are transferred from the readout gate channel 26 below the electrode to which the readout signal is applied among the vertical charge transfer electrodes 32.
[0029]
The vertical charge transfer electrode 32 and the vertical charge transfer channel 20 constitute a vertical charge transfer device (VCCD) 33 that transfers the signal charge generated at the pn junction of the photodiode 14 in the vertical direction. The surface of the substrate on which the vertical charge transfer electrode 32 is formed is covered with a surface protective film 36, and a light shielding film 38 made of tungsten is formed thereon, and only the light receiving area 40 of the photodiode is opened, and the other areas are It is configured to shield light.
[0030]
Further, the upper layer of the vertical charge transfer electrode 32 is covered with a planarizing insulating film 43 for planarizing the surface and a translucent resin film 44 formed on the upper layer, and a filter layer 46 is further formed on the upper layer. Yes. In the filter layer 46, a red filter layer 46R, a green filter layer 46G, and a blue filter layer 46B are sequentially arranged so as to form a predetermined pattern corresponding to each photodiode 14.
[0031]
Furthermore, this upper layer is melted after patterning by photolithography a transparent resin containing a photosensitive resin having a refractive index of 1.3 to 2.0 through the planarization insulating film 48, rounded by surface tension, and then cooled. Thus, the microlens array formed by the microlenses 50 is covered.
[0032]
Next, the manufacturing process of this solid-state imaging device will be described. As shown in FIGS. 2A to 2D and FIGS. 3A to 3C, the manufacturing method is positioned at the wafer level and integrated by mounting in a lump. This is based on the so-called CSP method in which each solid-state image sensor is separated. (Hereinafter, only 2 units are shown in the drawing, but a large number of solid-state image pickup devices are continuously formed on the wafer.) In this method, the solid-state image pickup device substrate and the glass substrate have the same edge, The back surface side is taken out through a through hole penetrating the solid-state imaging device substrate 100 and the reinforcing plate 701 attached to the back surface. Further, here, a sealing cover glass 200 with a spacer in which a spacer 203S is formed in advance is used.
[0033]
First, formation of a glass substrate with a spacer will be described.
As shown in FIG. 2A, a silicon substrate 203 serving as a spacer is attached to the surface of a glass substrate 201 via an adhesive layer 202 made of a UV curable adhesive, for example, a cationic polymerizable energy ray curable adhesive. Then, a resist pattern R1 is formed by photolithography. Besides this, a thermosetting adhesive can also be used.
[0034]
Then, as shown in FIG. 2B, the silicon substrate 203 is etched using the resist pattern as a mask in a state where the resist pattern R1 is left in the spacer portion by photolithography to form a spacer 203S. .
[0035]
Thereafter, as shown in FIG. 2 (c), with the resist pattern R1 for forming the spacer 203S remaining, the inter-spacer region except for the inter-element region is filled with the resist R, and the glass substrate is fixed to a predetermined area. By etching to the depth, the inter-element groove portion 204 is formed as shown in FIG. Further, an adhesive layer 207 is formed on the surface of the spacer. Here, since the spacer is formed of a silicon substrate, if etching is performed under such etching conditions that the etching rate of silicon oxide, which is the main component of the glass substrate, is sufficiently larger than the etching rate of silicon, Etching may be performed with the side wall of the spacer exposed in the inter-element region.
[0036]
Alternatively, photolithography may be performed again to form a resist pattern that includes the entire sidewall of the spacer, and the groove 204 may be formed by etching through the resist pattern. Thus, the sealing cover glass 200 in which the groove portion 204 and the spacer 203S are formed is obtained.
[0037]
Next, a solid-state image sensor substrate is formed. When forming the element substrate, as shown in FIG. 3A, a silicon substrate 101 (here, a 4 to 8 inch wafer is used) is prepared. (Hereinafter, only one unit is shown in the drawing, but a large number of solid-state image pickup devices are continuously formed on the wafer.) Then, a channel stopper layer is formed using a normal silicon process, and a channel region is formed. To form device regions such as charge transfer electrodes. A reinforcing plate 701 made of a silicon substrate on which a silicon oxide film is formed is bonded to the back surface of the solid-state imaging device substrate 100 by surface active room temperature bonding. (Fig. 3 (a))
[0038]
Thereafter, as shown in FIG. 3B, alignment is performed using alignment marks formed on the peripheral edge of each substrate, and a flat glass substrate 201 is formed on the solid-state imaging device substrate 100 formed as described above. The cover glass 200 to which the spacer 203S is bonded is placed on the substrate, and both are integrated by the adhesive layer 207 by heating. This step is preferably performed in a vacuum or in an inert gas atmosphere such as nitrogen gas.
[0039]
Then, a through hole H is formed from the back side of the reinforcing plate 701 by photolithography. Then, a silicon oxide film 109 is formed in the through hole H by the CVD method, and thereafter anisotropic etching is performed to leave the silicon oxide film 109 only on the side wall of the through hole as shown in FIG.
[0040]
Then, as shown in FIG. 4 (a), a tungsten film is formed as a conductor layer 108 for bonding pads and the contact to the through hole H by the CVD method using WF _6.
[0041]
Then, as shown in FIG. 4B, a bonding pad 113 is formed on the surface of the reinforcing plate 701, and a bump 114 is formed.
In this way, the signal extraction electrode terminal and the energization electrode terminal can be formed on the reinforcing plate 701 side.
[0042]
Then, as shown in FIG. 4C, an anisotropic conductive film 115 (ACP) is applied to the surface of the reinforcing plate 701.
Finally, as shown in FIG. 4D, a circuit board 901 on which a drive circuit is formed is connected via this anisotropic conductive film 115. For connection, diffusion bonding, solder bonding, eutectic bonding, or the like can be applied. The circuit board 901 is provided with a contact layer 117 made of a conductor layer filled in a through hole H formed so as to penetrate the board and a bonding pad 118.
Therefore, connection with a circuit board such as a printed circuit board can be easily achieved through the bonding pad 118. The contact layer 117 is formed so as to be aligned with the conductor layer 108 formed on the solid-state imaging device substrate so as to be aligned on the same line.
[0043]
Thereafter, the entire device is diced along a dicing line DC including the contact layer 117 and the conductor layer 108 arranged on the same line, and is divided into individual solid-state imaging devices. (Although only one unit is shown in the drawing, a plurality of solid-state imaging devices are continuously formed on one wafer.) This wiring is basically composed of a combination of straight lines in the vertical direction, and is provided on the front or back surface. The connection in the horizontal direction may be performed with In addition, if a plurality of through holes are formed and an insulating layer is interposed in each region, it is possible to form a multilayer wiring on the side surface.
In this way, a solid-state imaging device can be formed very easily with good workability.
Since the reinforcing plate 701 is composed of a silicon substrate on which a silicon oxide film is formed, heat insulation or electrical insulation with the solid-state imaging device substrate 100 is possible.
In the above-described embodiment, the conductor layer is formed in the through hole H by the CVD method. However, the contact hole having a high aspect ratio and high workability can be easily obtained by using a plating method, a vacuum screen printing method, or a vacuum suction method. It is possible to fill the conductor layer.
Furthermore, in the above embodiment, the electrical connection between the front and back surfaces of the circuit board on which the solid-state imaging device substrate and the peripheral circuit are mounted using the through holes is not limited to this. It is also possible to form a contact so that the front and back are electrically connected by impurity diffusion.
In this way, the signal extraction electrode terminal and the energization electrode terminal can be formed on the reinforcing plate 701 side.
[0044]
Furthermore, since the individual parts are separated after being mounted together without performing individual positioning or electrical connection such as wire bonding, manufacturing is easy and handling is easy.
[0045]
Further, since the groove portion 204 is formed in the glass substrate 201 in advance and is removed from the surface to the depth reaching the groove portion 204 by a method such as CMP after mounting, it can be divided very easily. is there.
[0046]
In addition, since an individual solid-state imaging device can be formed only by cutting or polishing in a state where the element forming surface is sealed in the gap C by bonding, there is little damage to the element, no dust is mixed, It is possible to provide a highly reliable solid-state imaging device.
[0047]
Furthermore, since the silicon substrate is thinned to a depth of about one half by CMP, the size and thickness can be reduced. Furthermore, since the thickness is reduced after bonding with the glass substrate, it is possible to prevent a decrease in mechanical strength.
[0048]
As described above, according to the configuration of the present invention, since positioning is performed at the wafer level and integrated by mounting in a lump, and then separated for each solid-state imaging device, manufacturing is easy and reliable. It is possible to form a solid-state imaging device having a high height.
[0049]
In the embodiment described above, the wafer level CSP is used for batch connection and dicing. However, the solid-state imaging device substrate 100 in which the through holes H are formed and the bumps 114 are formed is diced one by one. Alternatively, the sealing cover glass 200 may be fixed.
The microlens array can also be formed by forming a transparent resin film on the surface of the substrate and forming a lens layer having a refractive index gradient at a predetermined depth by ion transfer from the surface.
[0050]
In addition to the silicon substrate, glass, polycarbonate or the like can be appropriately selected as the spacer.
[0051]
(Second Embodiment)
Next, a second embodiment of the present invention will be described.
In the first embodiment, the through hole H is formed so as to penetrate the reinforcing plate 701 and the conductor layer 111 is formed. However, in the present embodiment, a silicon substrate in which holes (vertical holes) are formed in advance is used. To form a solid-state imaging device substrate. Thereby, since the formation depth of the vertical hole can be shallow, productivity can be improved and the manufacturing yield can be improved.
Other parts are formed in the same manner as in the first embodiment.
That is, as shown in FIG. 5A, prior to forming the solid-state imaging device, first, a resist pattern is formed on the back surface of the silicon substrate by photolithography, and RIE (reactive ion etching) is performed using this resist pattern as a mask. Thus, the vertical hole 118 is formed. In this step, a pad 110 made of aluminum or the like is formed on the surface, and a vertical hole 118 is formed so as to reach this pad.
[0052]
Then, as shown in FIG. 5B, a silicon oxide film 119 is formed on the inner wall of the vertical hole by the CVD method.
And as shown in FIG.5 (c), the element area | region for solid-state image sensor formation was formed using the normal silicon process like the said each embodiment.
And as shown in FIG.5 (d), it aligns with the alignment mark formed in the peripheral part of each board | substrate, on the solid-state image sensor board | substrate 100 formed as mentioned above, on the flat glass substrate 201 The cover glass 200 to which the spacer 203S is bonded is placed and heated, and both are integrated by the adhesive layer 207. Again, when the surface of the solid-state imaging device is Si, a metal, or an inorganic compound, the surface activation room temperature bonding may be used for the bonding step.
[0053]
Then, as shown in FIG. 5E, a reinforcing plate 701 is joined to the back surface side of the solid-state image pickup device substrate 100 by surface activation normal temperature joining, and the vertical holes 118 are formed by etching using photolithography from the back surface side. The through hole 108 is formed so as to reach. Again, it is desirable that the inner wall of the through hole be insulated. Moreover, you may make it use the reinforcement board which formed the through hole previously.
[0054]
Thereafter, the steps shown in FIGS. 4A to 4D described in the first embodiment are performed, and the positions of the through holes are formed so as to correspond to the end portions of the respective solid-state imaging devices. By dividing by a dicing line including this through hole, a solid-state imaging device having a structure in which even a circuit board on which peripheral circuits are formed is easily formed.
As described above, according to the present embodiment, the vertical hole can be formed with a shallow depth, so that the productivity can be improved and the manufacturing yield can be improved.
[0055]
(Third embodiment)
Next, a third embodiment of the present invention will be described.
In the second embodiment, the contacts are formed so as to penetrate the reinforcing plate 701, the solid-state imaging device substrate, and the circuit board, and the electrodes are taken out from the circuit board side. In this embodiment, FIG. As shown in (a) and (b), the conductive layer 120 as a wiring layer is formed on the side wall of the through hole via the insulating film 121, and the electrode is taken out from the side wall of the solid-state imaging device. To do. According to such a configuration, the wiring pattern can be given flexibility because it is insulated from the substrate.
The manufacturing process is formed in substantially the same manner as in the second embodiment, but the insulating film can be easily formed by performing CVD or pouring polyimide resin or the like prior to the formation of the conductor layer. In this manner, the position of the through hole is formed so as to correspond to the end portion of each solid-state imaging device, and the wiring layer is easily formed on the side wall via the insulating film by dicing with the cutting line DC including the through hole. It is possible to form a solid-state imaging device formed with
In addition, by configuring the conductor layer 120 filling the through hole with a light-shielding material such as tungsten, the solid-state imaging device is shielded from light so that malfunctions can be reduced.
Further, if this reinforcing plate is made of polyimide resin, ceramic, crystallized glass, a silicon substrate whose front and back surfaces are oxidized, etc., it can serve as a heat insulating substrate. Further, it may be formed of a moisture-proof sealing material or a light shielding material.
[0056]
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.
In the third embodiment, the through hole is formed inside the substrate and the wiring is formed on the side wall of the peripheral circuit substrate. In this example, as shown in FIG. 7, the glass substrate 201 and the spacer 203S The conductor layer 209 is formed on the side wall, the pad 210 is formed on the upper surface of the glass substrate, and the signal extraction terminal and the current supply terminal are formed above. Other portions are formed in the same manner as in the above embodiment.
[0057]
Next, the manufacturing process of this solid-state imaging device is shown in FIGS. 8 (a1) to 8 (f) and FIGS. 9 (a) to 9 (e).
[0058]
That is, in the first to third embodiments, a through hole is formed in the solid-state image pickup device substrate 100, a wiring pattern is formed on the side wall of the solid-state image pickup device substrate, and a signal extraction terminal and In contrast to forming the current supply terminal, in this method, the spacer 203S is attached to the glass substrate 201 constituting the sealing cover glass 200, and in this state, the through-hole 208 is formed so as to penetrate the spacer and the glass substrate. , A conductor layer is formed on this, and a wiring 209 is formed on the side wall of the spacer and the glass substrate by dividing by a dicing line DC including the through hole, and a signal is extracted on the surface of the sealing cover glass. A terminal and a current supply terminal are formed.
[0059]
That is, in the first embodiment, in the step shown in FIG. 3C, a through hole is formed in the solid-state image sensor substrate 100, and a signal extraction terminal and a current supply terminal are provided on the back side of the solid-state image sensor substrate. In contrast to this, in this method, the spacer 203S is attached to the glass substrate 201 constituting the sealing cover glass 200, and in that state, the through hole 208 is formed so as to penetrate the spacer and the glass substrate. A conductor layer is formed thereon, and a signal extraction terminal and a current supply terminal are formed on the surface of the sealing cover glass.
[0060]
First, as shown in FIG. 8A1, a silicon substrate 203 having a thickness of 30 to 120 μm for preparing a spacer is prepared.
Next, as shown in FIG. 8 (a2), a glass substrate 201 for constituting the sealing cover glass 200 is prepared.
Then, as shown in FIG. 8B, an adhesive layer 202 is applied to the surface of the substrate 203.
[0061]
Thereafter, as shown in FIG. 8C, a silicon substrate 203 coated with an adhesive layer 202 is adhered to the surface of the glass substrate 201.
[0062]
Subsequently, as shown in FIG. 8D, a resist pattern is formed by photolithography, RIE (reactive ion etching) is performed using the resist pattern as a mask, and a region corresponding to the photodiode, that is, a light receiving region (FIG. An adhesive is applied in advance so as to remove the recess 205 including the region corresponding to 40) in b), or after RIE, removal treatment is performed with oxygen plasma or the like.
[0063]
Subsequently, as shown in FIG. 8E, a resist pattern is formed by photolithography, RIE (reactive ion etching) is performed using the resist pattern as a mask, and a through hole is formed so as to penetrate the spacer 203S and the glass substrate 201. 208 is formed.
[0064]
Then, if necessary, a silicon oxide film (not shown) is formed at least on the inner wall of the spacer made of silicon by CVD.
Note that this step is not necessary when the spacer is formed of an insulator such as glass or resin. Further, a light shielding film may be formed on the inner wall or the outer wall of the spacer.
[0065]
Thereafter, as shown in FIG. 9A, a conductor layer 209 is formed on the inner wall of the through hole whose inner wall is insulated by vacuum screen printing or metal plating using a conductive paste such as silver paste or copper paste. A through contact region that penetrates the spacer 203S and the glass substrate 201 is formed.
[0066]
Then, as shown in FIG. 9B, gold bonding pads 210 and 211 or bumps 212 are formed on the front and back surfaces of the glass substrate with spacers so as to be connected to the through contact region. Here, when forming the film, a gold thin film is formed on the front surface and the back surface and patterned by an etching method using photolithography, or screen printing, selective plating, or the like can be applied.
[0067]
Furthermore, as shown in FIG. 9C, an anisotropic conductive resin film 213 is applied.
[0068]
On the other hand, as shown in FIG. 9D, a solid-state imaging device substrate 100 formed with a reinforcing plate 701 is prepared in the same manner as that used in the first embodiment.
[0069]
Then, as shown in FIG. 9 (e), alignment is performed using alignment marks formed on the peripheral edge of each substrate, and a flat glass substrate 201 and spacers are formed on the solid-state imaging device substrate 100 formed as described above. The cover glass 200 to which 203S is bonded is placed and heated, and both are integrated by the anisotropic conductive film 213. In the case of the solid-state imaging device substrate 100 and the sealing cover glass 200, in addition to the anisotropic conductive film, ultrasonic waves, eutectic crystals, solder, and the like can be used.
[0070]
Thereafter, the entire apparatus is diced along a dicing line DC including the through hole 208 and divided into individual solid-state imaging devices.
In this way, a solid-state imaging device in which a contact region such as a bonding pad is formed on the sealing cover glass is formed extremely easily and with good workability.
[0071]
(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.
In the fourth embodiment, the solid-state imaging device has been described in which a through-hole penetrating the glass substrate and the spacer is formed and a contact region such as a bonding pad is formed on the sealing cover glass. In the form, this modification will be described.
First, the present embodiment is characterized by the formation of a through hole in a spacer, and a glass substrate 201 is prepared as shown in FIG.
Then, as shown in FIG. 10B, a photocurable resin is formed on the surface of the glass substrate 201 by an optical modeling method, and a spacer 213 is formed.
Thereafter, as shown in FIG. 10C, a through hole 208 is formed by an etching method using photolithography.
Thus, it is possible to easily obtain a sealing cover glass having a spacer and a through hole.
After that, the mounting process shown in FIGS. 9A to 9E is executed in the same manner as described in the fourth embodiment, and is bonded to the solid-state imaging device substrate, and then dicing is performed. Thus, it is possible to obtain the solid-state imaging device shown in FIG.
According to this method, the spacer is easily formed. In this embodiment, a photo-curing resin is used, but the adhesive itself may be used. Since the glass substrate and the spacer are integrally formed, it is possible to reduce warpage and distortion, and manufacture is also easy.
[0072]
(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described.
In the fourth embodiment, a silicon substrate for spacer formation is attached to a glass substrate and patterned, but in this embodiment, the glass substrate is etched in one etching process. Thus, the recess and the through hole may be formed simultaneously. Other parts are formed in the same manner as in the fourth embodiment.
[0073]
First, in the present embodiment, a glass substrate 201 is prepared as shown in FIG.
Then, as shown in FIG. 11B, a resist pattern is formed on the back surface of the glass substrate 201, and a recess 205 is formed.
Thereafter, as shown in FIG. 11C, a through hole 208 is formed.
Thus, it is possible to easily obtain the sealing cover glass in which the spacers are integrally formed and the through holes are formed.
In this step, the through hole is formed after the recess is formed, but a part of the step may be performed in the same step. That is, a resist pattern R is formed on the front surface and the back surface of the glass substrate 201. Openings are formed on both front and back surfaces in a region where a through hole is to be formed, and a recess 205 and (a cutting groove 204 if necessary) are formed. The region to be provided has an opening only on the back side.
Thereafter, the glass substrate is etched from both sides using the front and back resist patterns as a mask, and a recess 205, a cutting groove (not shown), and a through hole 208 are formed simultaneously.
In this method, the etching time can be shortened and the through hole can be formed by etching from both sides, so that the etching accuracy can be improved.
After that, the mounting process shown in FIGS. 9A to 9E is executed in the same manner as described in the fourth embodiment, and is bonded to the solid-state imaging device substrate, and then dicing is performed. Thus, it is possible to obtain the solid-state imaging device shown in FIG.
Since the glass substrate and the spacer are integrally formed, it is possible to reduce warpage and distortion, and manufacture is also easy.
[0074]
(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described.
In the fourth embodiment, a silicon substrate for spacer formation is attached to a glass substrate and patterned, but in this embodiment, a spacer already patterned on the glass substrate 201. 203S is pasted, and finally a through hole is formed by an etching process. Other parts are formed in the same manner as in the fourth embodiment.
[0075]
First, in the present embodiment, a glass substrate 201 is prepared as shown in FIG.
On the other hand, as shown in FIG. 12A2, a silicon substrate 203 for spacer formation is prepared.
Then, as shown in FIG. 12B, the silicon substrate 203 is processed by an etching method using photolithography to obtain a spacer 203S.
[0076]
Thereafter, as shown in FIG. 12C, an adhesive 202 is applied to the surface of the patterned spacer.
Then, as shown in FIG. 38 (d), the spacer 203 </ b> S is adhered while being aligned with the glass substrate 201.
Thereafter, as shown in FIG. 12E, a through hole 208 is formed by an etching method using photolithography.
[0077]
In this way, it is possible to easily obtain a sealing cover glass in which a spacer is attached and a through hole is formed.
[0078]
Then, if necessary, a silicon oxide film (not shown) is formed at least on the inner wall of the spacer made of silicon by CVD.
Note that this step is not necessary when the spacer is formed of an insulator such as glass or resin. Further, a light shielding film may be formed on the inner wall or the outer wall of the spacer.
[0079]
After that, the mounting process shown in FIGS. 9A to 9E is executed in the same manner as described in the fourth embodiment, and is bonded to the solid-state imaging device substrate, and then dicing is performed. Thus, it is possible to obtain the solid-state imaging device shown in FIG.
[0080]
Note that the glass substrate and the spacer may be bonded to each other by applying an ultraviolet curable resin, a thermosetting resin, a combination thereof, or semi-cured adhesive application. In forming this adhesive, it is possible to appropriately select supply with a dispenser, screen printing, stamp transfer, and the like.
[0081]
Further, as shown in FIG. 12C, the light shielding film 215 may be formed by a method such as sputtering a tungsten film on the inner wall of the concave portion of the spacer.
This makes it possible to obtain good imaging characteristics without providing a separate light shielding film.
[0082]
(Eighth embodiment)
Next, an eighth embodiment of the present invention will be described.
In the fourth embodiment, an example in which a silicon substrate for spacer formation is attached to a glass substrate, patterned, and finally a through-hole penetrating the glass substrate and the spacer is formed by etching has been described. In this embodiment, as shown in FIGS. 13A1 to 13F, the spacer 203S formed to the through hole 208a shown in FIG. 13E1 by processing the shape by etching the silicon substrate and FIG. The glass substrate 201 on which the through-hole 208b shown in (b2) is formed is aligned using an alignment mark at the wafer level and bonded using the adhesive layer 202. Other portions are formed in the same manner as in the twenty-eighth embodiment.
[0083]
In this case, it is also possible to form the light shielding film (215) on the inner wall where the concave portion of the spacer is desired.
According to such a method, since the through holes are individually formed and bonded, alignment is necessary, but since the aspect ratio may be about half, the formation of the through holes becomes easy.
[0084]
After that, the mounting process shown in FIGS. 9A to 9E is executed in the same manner as described in the fourth embodiment, and is bonded to the solid-state imaging device substrate, and then dicing is performed. Thus, it is possible to obtain the solid-state imaging device shown in FIG.
[0085]
(Ninth embodiment)
Next, a ninth embodiment of the present invention will be described.
In the eighth embodiment, a silicon substrate for forming a spacer is attached to a glass substrate, a conductive layer 209 is formed in a through hole that penetrates the glass substrate and the spacer, and then the solid-state imaging device substrate 100 is mounted. In the present embodiment, as shown in FIGS. 14A to 14D, the above-described steps 4 to 8 are applied to the solid-state imaging device substrate 100 in which the reinforcing plate 701 is attached to the back surface. The glass substrate 200 with a spacer having the through hole 208 formed in the form is aligned and bonded at the wafer level, and then the conductor layer 209 is formed in the through hole 208. To do. A bonding pad 210 is formed so as to be connected to the conductor layer 209. Then, by dividing along the dicing line DC including the conductor layer 209, a solid-state imaging device having the conductor layer 209 on the side wall is formed. Other parts are formed in the same manner as in the fourth embodiment.
Again, when the conductor layer 209 is embedded, it can be easily formed by vacuum screen printing using a conductive paste such as copper paste or metal plating.
[0086]
In the above-described embodiment, the method of bonding the glass substrate and the spacer constituting the sealing cover glass and the spacer and bonding the solid-state imaging device substrate and the sealing cover glass using the adhesive layer has been described. However, in all the embodiments, when the spacer or the solid-state imaging device substrate surface is made of Si, metal, or inorganic compound, it can be appropriately joined by surface activated room temperature bonding without using an adhesive. If the cover glass is Pyrex, anodic bonding is also possible when the spacer is Si. When the adhesive layer is used, not only the UV adhesive but also a thermosetting adhesive, a semi-curable adhesive, and a thermosetting combined UV curable adhesive may be used as the adhesive layer.
[0087]
As described in the first embodiment, in all the embodiments, as a spacer, in addition to a silicon substrate, 42 alloy, metal, glass, photosensitive polyimide, polycarbonate resin, and the like can be appropriately selected.
[0088]
In addition, when the solid-state imaging device substrate and the sealing cover glass are joined using the adhesive layer, it is preferable that the melted adhesive layer does not flow out by forming a liquid reservoir. The same applies to the joint between the spacer and the solid-state imaging device substrate or the sealing cover glass. The melted adhesive layer flows out by forming a concave or convex portion in the joint and forming a liquid reservoir. Do not do it.
[0089]
Further, in the above-described embodiment, the separation into individual elements with respect to the one formed with the cut groove is performed up to the position of the cut groove. However, grinding, polishing, whole surface etching, or the like can also be used.
[0090]
Moreover, in the said embodiment, when using a reinforcement board (701), as a material, if it comprises a polyimide resin, a ceramic, crystallized glass, the silicon substrate etc. which oxidized the surface and the back surface as needed, heat insulation will be carried out. It can have the role of a substrate. Further, it may be formed of a moisture-proof sealing material or a light shielding material.
[0091]
Moreover, in the said embodiment, when bonding of a glass substrate and a spacer is required, you may be made to perform by ultraviolet curing resin, thermosetting resin, these combination, or semi-hardened adhesive application | coating. In forming this adhesive, it is possible to appropriately select supply with a dispenser, screen printing, stamp transfer, and the like.
[0092]
In addition, the examples described in the embodiments can be mutually modified within a range applicable to all forms.
[0093]
【The invention's effect】
As described above, according to the method of the present invention, positioning is performed at the wafer level and integrated by batch mounting, and then a conductor layer is formed in the through hole, and the dicing line including the through hole is formed. Therefore, it is possible to form the wiring layer on the side wall very easily.
[Brief description of the drawings]
FIGS. 1A and 1B are a cross-sectional view and an enlarged cross-sectional view showing a main part of a solid-state imaging device according to a first embodiment of the present invention.
FIGS. 2A to 2C are diagrams illustrating manufacturing steps of the solid-state imaging device according to the first embodiment of the present invention. FIGS.
FIG. 3 is a diagram showing a manufacturing process of the solid-state imaging device according to the first embodiment of the present invention.
FIG. 4 is a diagram showing a manufacturing process of the solid-state imaging device according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating a manufacturing process of the solid-state imaging device according to the second embodiment of the present invention.
FIG. 6 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the third embodiment of the present invention.
FIG. 7 is a diagram illustrating a solid-state imaging device formed in a manufacturing process according to a fourth embodiment of the present invention.
FIG. 8 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the fourth embodiment of the present invention.
FIG. 9 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the fourth embodiment of the present invention.
FIG. 10 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the fifth embodiment of the present invention.
FIG. 11 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the sixth embodiment of the present invention.
FIG. 12 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the seventh embodiment of the present invention.
FIG. 13 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the eighth embodiment of the present invention.
FIG. 14 is a diagram illustrating manufacturing steps of the solid-state imaging device according to the ninth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Solid-state image sensor board | substrate 101 Silicon substrate 102 Solid-state image sensor 200 Sealing cover glass 201 Glass substrate 203S Spacer

Claims (9)

A semiconductor substrate formed with a solid-state image sensor;
A translucent member connected to the semiconductor substrate so as to have a gap facing the light receiving region of the solid-state imaging device,
The semiconductor substrate has a wiring portion on a side surface and is disposed on a support member. The solid-state imaging device according to claim 1, wherein the supporting member is a semiconductor substrate on which a peripheral circuit is formed, and the semiconductor substrate is connected to the solid-state imaging element via the wiring portion. Forming a plurality of solid-state imaging elements on the surface of the first semiconductor substrate;
Bonding the translucent member to the surface of the first semiconductor substrate so as to have a gap facing each light receiving region of the solid-state imaging device;
Bonding the first semiconductor substrate to a support substrate;
Forming a through-groove penetrating the semiconductor substrate and having an inner wall formed into a conductor in a separation region for separating each solid-state imaging device on the first semiconductor substrate and its peripheral portion; and
Solid-state imaging of the joined body obtained in the joining step is performed in the separation region so as to leave a side wall wiring portion constituted by a part of a through groove in which the inner wall is made conductive on the side wall of each solid-state imaging device. And a step of separating each element. A method for manufacturing a solid-state imaging element. A plurality of solid-state imaging devices are formed on the surface of the first semiconductor substrate, and an inner wall is formed through the first semiconductor substrate in a separation region for separating each solid-state imaging device on the first semiconductor substrate and its peripheral portion. Forming a conductive through groove, and
Bonding the translucent member to the surface of the first semiconductor substrate so as to have a gap facing each light receiving region of the solid-state imaging device;
Bonding the first semiconductor substrate to a support substrate;
Solid-state imaging of the joined body obtained in the joining step is performed in the separation region so as to leave a side wall wiring portion constituted by a part of a through groove in which the inner wall is made conductive on the side wall of each solid-state imaging device. And a step of separating each element. A method for manufacturing a solid-state imaging element. The step of bonding the translucent member includes:
Preparing a translucent substrate having a plurality of recesses at a position corresponding to the formation region of the solid-state imaging device;
The method for manufacturing a solid-state imaging device according to claim 3, further comprising a step of bonding the translucent substrate to the surface of the semiconductor substrate. Prior to the bonding step, the method includes a step of forming a protrusion on the surface of the first semiconductor substrate so as to surround the light receiving region, and the protrusion forms a gap between the light receiving region and the translucent member. 5. The method for manufacturing a solid-state imaging device according to claim 3, wherein the solid-state imaging device is manufactured. The bonding step is characterized in that a gap is formed between the first semiconductor substrate and the translucent member via a spacer disposed so as to surround the light receiving region. The manufacturing method of the solid-state imaging device according to claim 3 or 4. The step of forming the through groove includes
The solid-state imaging device according to claim 3, comprising a step of forming a through groove in the semiconductor substrate and a step of forming a conductor layer in the through groove by a vacuum screen printing method. Manufacturing method. The step of forming the through groove includes
The solid-state imaging device according to claim 3, comprising a step of forming a through groove in the semiconductor substrate and a step of forming a conductor layer in the through groove by a vacuum suction method. Production method.

Images