JP4382543B2 - Manufacturing method of solid-state imaging device - Google Patents

Description

  The present invention relates to a method for manufacturing a solid-state imaging device and a method for manufacturing an electrode.

  FIG. 14 is a plan view showing the structure of a conventional solid-state image sensor 51. FIGS. 15A and 15B are a sectional view taken along line II and a sectional view taken along line II-II in FIG. 14, respectively.

  Referring to FIG. 15, a photoelectric conversion unit 53, a separation region 55, and a charge transfer region 57 are formed on the light receiving surface side of the substrate 52. A gate reading unit 59 is provided between the photoelectric conversion unit 53 and the charge transfer region 57. On the substrate 52, a gate insulating film 61, a first transfer electrode 63, a second transfer electrode 65, and an interlayer insulating film 67 are formed. The first transfer electrode 63 and the second transfer electrode 65 are insulated by an interlayer insulating film 67. The planar positional relationship among the photoelectric conversion unit 53, the first transfer electrode 63, the second transfer electrode 65, and the interlayer insulating film 67 is as shown in FIG.

  Such a solid-state imaging device 51 has been manufactured by the following method (for example, refer to Patent Document 1).

  First, the photoelectric conversion unit 53, the separation region 55, and the charge transfer region 57 are formed on the light receiving surface side of the substrate 52. Next, a gate insulating film 61 is formed on the substrate 52. Next, a first transfer electrode conductor is formed thereon, and is patterned by photolithography and etching to form the first transfer electrode 63. Next, an interlayer insulating film 67 that covers the first transfer electrode 63 is formed.

  Next, a second transfer electrode conductor is formed on the entire surface of the obtained substrate. Next, the second transfer electrode conductor on the first transfer electrode 63 is removed by polishing by a CMP method. Next, the remaining second transfer electrode conductor is patterned by photolithography and etching to form the second transfer electrode 65, thereby obtaining the structure shown in FIG.

Thereafter, an insulating film, a light shielding film, a passivation film, a planarizing film, a color filter layer, an on-chip lens, and the like (all not shown) are formed, and the manufacture of the conventional solid-state imaging device 51 is completed.
JP 11-26743 A

  According to the above method, after the first transfer electrode 63 is formed, photolithography and etching are performed again to form the second transfer electrode 65. Since these are formed in separate steps, misalignment may occur between them. Therefore, this positional shift must be taken into account when opening the light shielding film, and the opening area of the light shielding film is reduced, resulting in a decrease in sensitivity.

  The present invention has been made in view of such circumstances, and provides a method for manufacturing a solid-state imaging device capable of suppressing a positional shift between a first transfer electrode and a second transfer electrode.

  The method for manufacturing a solid-state imaging device according to the present invention includes: (1) a plurality of photoelectric conversion units arranged substantially in a line on the light-receiving surface side of the substrate and extending substantially parallel to each other; Forming a photoelectric conversion unit row; (2) forming a template layer having a first elongated portion between adjacent photoelectric conversion unit rows; and (3) crossing the photoelectric conversion unit row and substantially A plurality of elongated first transfer electrode conductors are formed so as to extend in parallel and to enter the first opening, and (4) the first transfer electrode conductive material that has entered the first opening. An interlayer insulating film is formed on the side surface of the body and at a position lower than the upper surface of the mold layer, and (5) second transfer electrode conductors are embedded so as to fill the gaps between the adjacent first transfer electrode conductors. (6) the first and second transfer electrode conductors are insulated from each other. By flattening the conductors for the first and second transfer electrodes as provided by patterning a conductor for the first and second transfer electrodes, the step of forming the first and second transfer electrodes.

  According to the present invention, the template layer serving as the template for the first and second transfer electrodes is formed in advance on the substrate, and the first and second transfer electrodes are formed using this template layer. A positional shift between the first transfer electrode and the second transfer electrode can be suppressed. For this reason, the opening of the light shielding film normally formed in the subsequent process can be enlarged, and the sensitivity of the solid-state imaging device can be improved.

1. First Embodiment A manufacturing method of a solid-state imaging device according to a first embodiment of the present invention includes (1) a plurality of photoelectric conversion units arranged substantially in a line on the light receiving surface side of a substrate, and Forming a plurality of photoelectric conversion part rows so as to extend substantially parallel to each other, (2) forming a template layer having a first elongated portion between adjacent photoelectric conversion part rows, and (3) A plurality of elongated first transfer electrode conductors are formed so as to intersect the photoelectric conversion unit rows, extend substantially parallel to each other, and enter the first opening in the first opening. An interlayer insulating film is formed on the side surface of the first transfer electrode conductor that has entered into one opening and lower than the upper surface of the template layer, and (5) each of the adjacent first transfer electrode conductors A second transfer electrode conductor is formed so as to fill the gap, and (6) the first and first conductors are formed. The first and second transfer electrode conductors are patterned by planarizing the first and second transfer electrode conductors so that the two transfer electrode conductors are insulated from each other. Forming a transfer electrode.

1-1. Step (1) A step of forming a plurality of photoelectric conversion unit rows on the light-receiving surface side of the substrate, which are composed of a plurality of photoelectric conversion units arranged substantially in a row and extend substantially parallel to each other.

  A plurality of photoelectric conversion unit rows are formed on the light receiving surface side of the substrate. The photoelectric conversion unit rows extend substantially parallel to each other. Moreover, each photoelectric conversion unit row is composed of a plurality of photoelectric conversion units arranged substantially in a row. Therefore, the plurality of photoelectric conversion units are substantially arranged in a matrix. In addition, it is preferable to form a separation region adjacent to each photoelectric conversion unit. In this case, the adjacent solid-state imaging devices are separated from each other. In general, a charge transfer region is formed at a predetermined interval with respect to the photoelectric conversion unit. This predetermined interval becomes a read gate portion. Further, the upper portion of the charge transfer region becomes the first opening, and the first and second transfer electrodes are formed here.

  As the substrate, a semiconductor substrate such as silicon can be used. The substrate itself may be n-type or p-type, and an n-type or p-type well may be formed in a region where the photoelectric conversion portion is formed.

1-2. Step (2) Step of forming a template layer having a long and narrow first opening between adjacent photoelectric conversion unit rows

The template layer can be formed of an insulating layer (made of an oxide layer such as a silicon oxide layer, a nitride layer such as silicon nitride, or a laminate of these layers). The mold layer may be formed of a semiconductor or a conductor. The template layer preferably has a thickness of about 100 to 1000 nm. The template layer can be formed, for example, by forming an insulating layer on a substrate and etching a predetermined region by dry etching. At this time, it is preferable that the first opening of the mold layer has a side wall formed at an angle of 90 to 135 degrees with respect to the substrate surface (see θ in FIG. 7). When the angle is 90 degrees or more, patterning by etching of the first transfer electrode conductor is facilitated in a later process. This is because, as a result, the first or second transfer electrode can effectively apply an electric field to the charge transfer region or gate readout portion formed thereunder. In order to increase the angle to 90 or more, for example, an etching may be performed by adding an additive gas (C ₄ F ₈ or the like) that causes deposition in the etching gas. In this case, for example, carbon-based deposition occurs on the side wall of the first opening, and the side wall is at an angle of 90 degrees or more with respect to the substrate surface. Further, the angle can be set to 135 degrees or less by appropriately changing the ratio of the additive gas or the pressure of the etching gas.

  A casting_mold | template layer may have an elongate 1st opening part only between each photoelectric conversion part row | line | column adjacent to each other. In this case, the first opening has a groove shape, and there is no opening between adjacent photoelectric conversion units belonging to the same photoelectric conversion unit row. Further, the first and second transfer electrodes finally formed have a rectangular shape or the like. In addition, since the first transfer electrodes formed from the adjacent first openings are not electrically connected to each other, it is necessary to separately perform wiring in a subsequent process. The same applies to the second transfer electrode. For wiring, for example, after forming a light-shielding film in a later process, contact holes reaching each transfer electrode are formed, and the contact holes are filled with a conductor such as tungsten, and the adjacent contact holes are electrically connected to each other. This is done by forming a conducting wire. For portions where contact holes or conductive wires are to be formed, the light shielding film is removed in advance. Further, when such a template layer is used, by forming the first transfer electrode conductor so that the plurality of first transfer electrode conductors correspond to the respective photoelectric conversion units, the 2 + n-phase driving method can be realized. Even a CCD can be manufactured in the same process as a two-phase drive type CCD. Note that “a plurality of first transfer electrode conductors correspond to each photoelectric conversion unit” means, for example, that a plurality of first transfer electrode conductors pass above each photoelectric conversion unit. It means a case where a transfer electrode conductor is formed, and as a result, a plurality of first transfer electrodes are formed in the same first opening adjacent to each photoelectric conversion portion. At this time, a second transfer electrode is formed between adjacent first transfer electrodes.

  Each of the template layers is a photoelectric conversion unit adjacent to each other, and has a second opening between those belonging to the same photoelectric conversion unit row, and the second opening is adjacent to the second opening with the second opening interposed therebetween. One opening may be connected. By forming the template layer in such a shape, the first transfer electrodes formed from the adjacent first openings are electrically connected to each other. In this case, it is advantageous in that it is not necessary to provide a wiring between them in the subsequent process to be electrically connected. The same applies to the second transfer electrode.

1-3. Step (3) A plurality of elongated first transfer electrode conductors are formed so as to intersect the photoelectric conversion unit rows, extend substantially parallel to each other, and enter the first opening in the first opening. Process

  Before this step, usually, a step of forming a gate insulating film on the obtained substrate is provided. The gate insulating film is made of an oxide film, a nitride film, or a laminated film thereof. The oxide film or nitride film is made of, for example, a silicon oxide film or a silicon nitride film, respectively. The thickness of the gate insulating film is preferably 50 to 100 nm. The gate insulating film is formed by, for example, stacking a silicon oxide film, a silicon nitride film, and a silicon oxide film in this order. Moreover, the thickness is 30 nm, 40 nm, and 10 nm, respectively, for example.

  The plurality of elongated first transfer electrode conductors are preferably orthogonal to the photoelectric conversion unit row. Each of the first transfer electrode conductors may be composed of a plurality of parts that are electrically or physically separated. For example, the first transfer electrode conductor may be divided on the template layer. The first transfer electrode conductor is formed in the first opening so as to enter the first opening, and this part is processed into the first transfer electrode in a later step. The first transfer electrode conductor is made of polysilicon doped with impurities. The impurity is n-type or p-type. This impurity can be introduced into the polysilicon by, for example, adding the impurity when forming the polysilicon layer, or performing ion implantation after forming the polysilicon layer.

  The first transfer electrode conductor can be formed, for example, by forming a conductor layer on the obtained substrate and patterning the conductor layer using photolithography, an etching technique, or the like. The width between the adjacent first transfer electrode conductors is preferably substantially the same as or slightly larger than the width of the first transfer electrode conductor. This is because with such a configuration, the sizes of the first transfer electrode and the second transfer electrode can be made substantially the same. The first transfer electrode conductor preferably has a thickness of 50 to 1000 nm.

  When the template layer has the second opening, the first transfer electrode conductor is formed so as to enter the second opening in the second opening and fill a part of the second opening. It is preferable. By filling a part of the second opening with the first transfer electrode conductor, the first transfer electrodes formed from the adjacent first openings are electrically connected to each other. Further, an interlayer insulating film is formed on the side surface of the first transfer electrode conductor that has entered the second opening and is lower than the upper surface of the template layer, and then the remainder of the second opening is transferred to the second transfer. By filling with the electrode conductor, the second transfer electrodes formed from the adjacent first openings are electrically connected to each other.

1-4. Step (4) A step of forming an interlayer insulating film on the side surface of the first transfer electrode conductor that has entered the first opening and lower than the upper surface of the template layer. The interlayer insulating film is a silicon oxide film or the like Insulating film or the like. The interlayer insulating film preferably has a thickness of 150 nm or less. This is because if the thickness is 150 nm or less, the gap between the charge transfer electrodes becomes small, and it is possible to easily prevent the charge from being missed.

  The interlayer insulating film can be formed, for example, by thermally oxidizing the first transfer electrode conductor. This method can be particularly suitably used when the first transfer electrode conductor is made of polysilicon.

  Further, the interlayer insulating film may be formed by forming an insulating film covering the first transfer electrode conductor by a CVD method or the like and etching back the insulating film. The insulating film is made of silicon oxide or the like. The insulating film preferably has a thickness of 60 to 150 nm. This is because in this case, the gap between the charge transfer electrodes becomes small, and it is possible to easily prevent the charge from being missed. Etch back can be performed by a dry etching method or the like. Thereby, an interlayer insulating film can be formed only on the side surface of the first transfer electrode conductor. Further, according to this method, it is easy to control the thickness of the interlayer insulating film formed by the etch back by controlling the thickness of the insulating film formed first.

1-5. Step (5) Step of forming a second transfer electrode conductor so as to fill a space between adjacent first transfer electrode conductors

  For example, the second transfer electrode conductor is formed on the entire obtained substrate. The second transfer electrode conductor can be formed of the same material, method and thickness as the first transfer electrode conductor.

  In the first opening, since the interlayer insulating film is formed on the side surface of the first transfer electrode conductor, the first and second transfer electrode conductors are insulated from each other in the first opening. .

1-6. Step (6): patterning the first and second transfer electrode conductors by planarizing the first and second transfer electrode conductors such that the first and second transfer electrode conductors are insulated from each other; And forming the first and second transfer electrodes

  The planarization is performed by, for example, a CMP method. As described above, since the first and second transfer electrode conductors are insulated from each other in the first opening, the first and second transfer electrode conductors are flattened to a position lower than the upper surface of the mold layer, for example. The second transfer electrode conductors are insulated from each other to form the first and second transfer electrodes. The side surfaces of the first and second transfer electrodes are along the side surface of the first opening. Therefore, unlike the prior art, it is not necessary to provide a margin that takes into account the positional deviation of the first and second transfer electrodes, so that the opening region of the light shielding film that is normally formed in the subsequent process can be increased. The sensitivity of the solid-state image sensor can be improved.

1-7. Other After the step (6), a step of removing the template layer is usually provided. This step can be performed by wet etching using HF, for example.

  Thereafter, a step of forming an insulating film, a light shielding film, a passivation film, a planarizing film, a color filter layer, an on-chip lens, and the like may be provided.

2. Second Embodiment An electrode manufacturing method according to a second embodiment of the present invention includes: (1) forming a template layer having a plurality of elongated first openings extending substantially parallel to each other on a substrate; 2) A plurality of elongated first electrode conductors are formed so as to intersect the first opening, extend substantially parallel to each other, and enter the first opening in the first opening; ) An interlayer insulating film is formed on the side surface of the first electrode conductor that has entered the first opening and lower than the upper surface of the template layer, and (4) each of the adjacent first electrode conductors Forming a second electrode conductor so as to fill the gap; and (5) planarizing the first and second electrode conductors such that the first and second electrode conductors are insulated from each other. And patterning the first and second electrode conductors to form the first and second electrodes. Is provided.

  In the step (1), the template layer has a second opening that connects two adjacent first openings. In the step (2), the first electrode conductor is a second opening. In step (2), the step (2) is formed on the side surface of the first electrode conductor that has entered the first or second opening. And forming an interlayer insulating film at a position lower than the upper surface of the mold layer. In the step (4), between the two adjacent first electrode conductors and the remainder of the second opening, It may be a step of forming the second electrode conductor so as to be buried.

  The description of the first embodiment basically applies to the second embodiment. The present invention can be used for manufacturing not only a transfer electrode of a solid-state imaging device but also a general electrode. In particular, the present invention can be effectively used when it is necessary to strictly determine the positional relationship between a plurality of electrodes.

  FIG. 1 is a plan view showing the structure of a solid-state imaging device 1 according to Embodiment 1 of the present invention. 2, (a), (b), and (c) are an II sectional view, an II-II sectional view, and a III-III sectional view in FIG. 1, respectively.

  Referring to FIG. 2, the photoelectric conversion unit 3, the separation region 5, and the charge transfer region 7 are formed on the light receiving surface side of the substrate 2. A gate reading unit 9 is between the photoelectric conversion unit 3 and the charge transfer region 7. A gate insulating film 11, a first transfer electrode 13, a second transfer electrode 15, and an interlayer insulating film 17 are formed on the substrate 2. In addition, a well-known thing can be used for a light shielding film, a passivation film, a planarization film | membrane, a color filter layer, an on-chip lens, etc., It does not show in figure here.

  The first transfer electrode 13 and the second transfer electrode 15 are insulated by an interlayer insulating film 17. Further, the planar positional relationship among the photoelectric conversion unit 3, the first transfer electrode 13, the second transfer electrode 15, and the interlayer insulating film 17 is as shown in FIG.

  Hereinafter, the manufacturing method of the solid-state image sensor 1 of a present Example is demonstrated using FIGS.

  3 to 6, (a), (b), and (c) are an II sectional view, an II-II sectional view, and a III-III sectional view in FIG. 1, respectively.

  First, a plurality of photoelectric conversion unit rows 3a are formed on the light receiving surface side of the substrate 2 made of single crystal silicon. These photoelectric conversion unit rows 3a extend substantially parallel to each other. Each photoelectric conversion unit row 3a is composed of a plurality of photoelectric conversion units 3 arranged substantially in a row. Next, the isolation region 5 and the charge transfer region 7 are formed. These are formed by a known method such as ion implantation.

Next, a silicon oxide film having a film thickness of 250 nm is formed by CVD, and dry etching is performed leaving the upper portion of the photoelectric conversion portion, thereby forming a patterned template layer 19 to obtain the structure shown in FIG. . At this time, the first openings 23 are formed between the adjacent photoelectric conversion unit rows 3a. Moreover, the 2nd opening part 25 which connects the respectively adjacent 1st opening part 23 between the photoelectric conversion parts 3 which are each adjacent, and belong to the same photoelectric conversion part row | line | column 3a is formed. Dry etching is performed by adding C ₄ F ₈ to the etching gas. In this case, carbon-based deposition occurs on the side wall of the first opening 23, and the angle θ of the side wall becomes 90 degrees or more with respect to the surface of the substrate 2. Further, the angle θ is set to 135 degrees or less by appropriately adjusting the ratio of the additive gas or the pressure of the etching gas. This is shown in FIG. FIG. 7 corresponds to FIG. In the drawings other than FIG. 7, for the sake of convenience, the angle of the side wall of the first opening 23 with respect to the surface of the substrate 2 is expressed by 90 degrees.

  Next, a gate insulating film 11 is formed by stacking a silicon oxide film having a thickness of 30 nm, a silicon nitride film having a thickness of 40 nm, and a silicon oxide film having a thickness of 10 nm in this order on the obtained substrate. Get the structure shown.

  Next, a plurality of first transfer electrode conductors 13a intersecting with the photoelectric conversion unit rows 3a are formed. The first transfer electrode conductors 13a extend substantially parallel to each other, and are formed in the first opening 23 so as to enter the first opening 23. In addition, the first transfer electrode conductor 13 a is formed so as to enter the second opening 25 in the second opening 25 and fill a part of the second opening 25. In FIG. 5A, the first transfer electrode conductor 13a visible in the back is indicated by a dotted line.

  The first transfer electrode conductor 13a is formed by forming a polysilicon layer with a film thickness of 300 nm by a CVD method and patterning it by photolithography and etching techniques. The polysilicon layer is formed while adding impurities.

  Next, the first transfer electrode conductor 13a is thermally oxidized to form an interlayer insulating film 17 having a thickness of 100 nm, thereby obtaining the structure shown in FIG.

  Here, the interlayer insulating film 17 may be formed by forming a silicon oxide film with a thickness of 110 nm by a CVD method and dry-etching this film. In this case, the interlayer insulating film 17 is formed only on the side surface of the first transfer electrode conductor 13a. Further, since the film thickness of the gate insulating film 11 may decrease during the etch back, if necessary, for example, a silicon oxide 11a having a film thickness of 10 nm is deposited after the etch back to reduce the film thickness. Make up. This state is shown in FIG. FIG. 8 corresponds to FIG.

  Next, a second transfer electrode conductor 15a is formed on the entire surface of the obtained substrate to obtain the structure shown in FIG. The second transfer electrode conductor 15a is formed by forming a polysilicon layer with a film thickness of 300 nm by a CVD method and patterning it by photolithography and etching techniques. The polysilicon layer is formed while adding impurities. The second transfer electrode conductor 15a fills between the adjacent first transfer electrode conductors 13a and the remainder of the second opening 25.

  Next, the first and second transfer electrode conductors 13a and 15a are planarized by CMP until the template layer 19 is exposed, thereby patterning the first and second transfer electrode conductors 13a and 15a. Thus, the first and second transfer electrodes 13 and 15 are formed. Next, the template layer 19 is removed by wet etching using HF to obtain the structure shown in FIG.

  Thereafter, an insulating film, a light shielding film, a passivation film, a planarizing film, a color filter layer, an on-chip lens, and the like (all not shown) are formed, and the manufacture of the solid-state imaging device 1 according to the first embodiment is completed. .

  FIG. 9 is a plan view showing a structure of the solid-state imaging device 31 according to the second embodiment of the present invention. The difference from the first embodiment is that in the second embodiment, the first and second transfer electrodes 13 and 15 are rectangular.

  Hereinafter, a method for manufacturing the solid-state imaging device 31 of the present embodiment will be described with reference to FIGS. 10 and 11, (a), (b), and (c) are an II sectional view, an II-II sectional view, and a III-III sectional view, respectively, in FIG. 9.

  First, on the light receiving surface side of the substrate 2 made of single crystal silicon, a plurality of photoelectric conversion unit rows 3a each formed by arranging a plurality of photoelectric conversion units 3 substantially in a row is formed. These photoelectric conversion unit rows 3a extend substantially parallel to each other. Next, the isolation region 5 and the charge transfer region 7 are formed. These are formed by a known method such as ion implantation.

  Next, a 250 nm-thickness silicon oxide film is formed by CVD, and patterned by dry etching to form a template layer 19 that covers the photoelectric conversion portion array, thereby obtaining the structure shown in FIG. Unlike the first embodiment, the template layer 19 does not have the second opening 25 between adjacent photoelectric conversion units 3 that belong to the same photoelectric conversion unit row 3a. For this reason, the 1st and 2nd transfer electrodes 13 and 15 formed in a present Example become rectangular shape.

  Thereafter, the process is the same as in Example 1 until the light shielding film is formed. For reference, the structure after the first transfer electrode conductor 13a is formed and the first transfer electrode conductor 13a is thermally oxidized to form an interlayer insulating film 17 having a thickness of 100 nm is shown in FIG. Shown in This corresponds to FIG. 5 of the first embodiment.

  In Example 2, after forming a light-shielding film (not shown), contact holes reaching the transfer electrodes 13 and 15 are formed, and the contact holes are filled with a conductor such as tungsten, and adjacent contact holes are formed. Conductors are formed that are electrically connected to each other. For portions where contact holes or conductive wires are to be formed, the light shielding film is removed in advance.

  Thereafter, a passivation film, a planarizing film, a color filter layer, an on-chip lens, etc. (all not shown) are formed, and the manufacture of the solid-state imaging device 31 according to the second embodiment is completed.

  FIG. 12 is a plan view showing the structure of the solid-state imaging device 41 according to the third embodiment of the present invention. The difference from the second embodiment is that, in the third embodiment, four transfer electrodes are formed in each photoelectric conversion unit 3 and a four-phase driving method is adopted. The four transfer electrodes include two first transfer electrodes 13 and two second transfer electrodes 15.

  Hereinafter, the manufacturing method of the solid-state image sensor 41 of the present embodiment will be described with reference to FIG. In FIG. 13, (a), (b), and (c) are an II sectional view, an II-II sectional view, and an III-III sectional view, respectively, in FIG.

The steps until the template layer 19 is formed are the same as those in the second embodiment.
Next, the first transfer electrode conductors 13a are formed so that the two first transfer electrode conductors 13a correspond to the photoelectric conversion units 3, and the structure shown in FIG. 13 is obtained.
The subsequent steps are the same as those in the second embodiment.

  As described above, according to the present embodiment, by changing the number of first transfer electrode conductors 13a corresponding to each photoelectric conversion unit 3, it is possible to easily form a solid-state imaging device of a 2 + n-phase driving method. I understand that I can do it.

It is a top view which shows the structure of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the structure of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 1 of this invention. It is sectional drawing which shows the angle of the slope of the 1st opening part of the casting_mold | template layer based on Example 1 of this invention. It is sectional drawing which shows the structure of the interlayer insulation film based on Example 1 of this invention. It is a top view which shows the structure of the solid-state image sensor which concerns on Example 2 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 2 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 2 of this invention. It is a top view which shows the structure of the solid-state image sensor which concerns on Example 3 of this invention. It is sectional drawing which shows the manufacturing process of the solid-state image sensor which concerns on Example 3 of this invention. It is a top view which shows the structure of the conventional solid-state image sensor. It is sectional drawing which shows the structure of the conventional solid-state image sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31, 41, 51 Solid-state image sensor 2, 52 Board | substrate 3, 53 Photoelectric conversion part 3a Photoelectric conversion part row | line | column 5,55 Separation area | region 7,57 Charge transfer area | region 9,59 Gate readout part 11,61 Gate insulating film 13, 63 First transfer electrode 15, 65 Second transfer electrode 13 a First transfer electrode conductor 15 a Second transfer electrode conductor 17, 67 Interlayer insulating film 19 Template layer 23 First opening 25 Second opening

Claims (8)

  On the light receiving surface side of the substrate, a plurality of photoelectric conversion unit rows are formed so as to be substantially parallel to each other, and (2) are adjacent to each other. Forming a template layer having a long and narrow first opening between the photoelectric conversion unit rows; (3) intersecting the photoelectric conversion unit row and extending substantially parallel to each other; A plurality of elongated first transfer electrode conductors are formed so as to enter the opening, and (4) on the side surface of the first transfer electrode conductor that has entered the first opening, and more than the upper surface of the template layer. An interlayer insulating film is formed at a low position, (5) a second transfer electrode conductor is formed so as to fill between the adjacent first transfer electrode conductors, and (6) first and second transfers. Flatten the first and second transfer electrode conductors so that the electrode conductors are insulated from each other. By reduction, by patterning a conductor for the first and second transfer electrodes, the manufacturing method of the solid-state imaging device comprising a step of forming a first and second transfer electrodes. In the step (2), each of the template layers is a photoelectric conversion unit adjacent to each other, and has a second opening between those belonging to the same photoelectric conversion unit row, and the second opening sandwiches the second opening. Connect adjacent first openings with
In the step (3), the first transfer electrode conductor is formed in the second opening so as to enter the second opening and fill a part of the second opening,
Step (4) is a step of forming an interlayer insulating film on the side surface of the first transfer electrode conductor that has entered the first or second opening and at a position lower than the upper surface of the mold layer.
Step (5) is a step of forming the second transfer electrode conductor so as to fill in the space between the adjacent first transfer electrode conductors and the remainder of the second opening.
The manufacturing method according to claim 1. In step (2), the template layer is formed by forming an insulating layer on the substrate and etching a predetermined region by dry etching.
The manufacturing method according to claim 1, wherein the first opening of the mold layer has a side wall formed at an angle of 90 to 135 degrees with respect to the substrate surface.   The manufacturing method according to claim 1, wherein in the step (3), the plurality of first transfer electrode conductors correspond to the respective photoelectric conversion units.   2. The manufacturing method according to claim 1, wherein in step (4), the interlayer insulating film is formed by thermally oxidizing the first transfer electrode conductor.   2. The manufacturing method according to claim 1, wherein in step (4), the interlayer insulating film is formed by forming an insulating film covering the first transfer electrode conductor by a CVD method and etching back the insulating film.   The manufacturing method according to claim 5 or 6, wherein the interlayer insulating film has a thickness of 150 nm or less.   The manufacturing method according to claim 1, wherein in the step (6), the planarization is performed by a CMP method.

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