JP2014093324A - Method for manufacturing semiconductor device, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device, capable of achieving a low frequency of having a defective post electrode, and to provide the semiconductor device.SOLUTION: The method for manufacturing a semiconductor device comprises the steps of: forming a first resist 104, including a plurality of first openings 104a, above a substrate 101; forming a plurality of first electrodes 105 corresponding to the first openings 104a by electrolytic plating; forming a second resist 106 including a second opening 106a that is on a first electrode 105a, out of the multiple first electrodes 105, whose upper surface is positioned at a height equal to or lower than a first predetermined value H1, on the first resist 104; and forming a second electrode 107 using the second resist 106 by electrolytic plating on the first electrode 105a whose upper surface is positioned at a height equal to or lower than the first predetermined value H1.

Description

  The present invention relates to a semiconductor device manufacturing method and a semiconductor device, and more particularly to a post electrode forming method and a post electrode.

  In recent years, with the downsizing of electronic devices such as mobile phones and digital cameras, there is a strong demand for reducing the size of semiconductor devices mounted on electronic devices. In particular, the wafer level chip size package (WL-CSP) can reduce the package size to the semiconductor chip size. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-299996) and Patent Document 2 (Japanese Patent No. 4771658) disclose copper (Cu) by an electrolytic plating process as an electrode structure applicable to a semiconductor device such as WL-CSP. A post electrode in which two layers are stacked is described.

JP 2002-299596 A Japanese Patent No. 4771658

  However, when a plurality of post electrodes are formed over the entire surface of the semiconductor wafer by electrolytic plating, the plating growth rate differs depending on the position on the surface of the semiconductor wafer, so there is a difference in the height of the plurality of post electrodes. Arise. In particular, when the post electrode is formed high, the difference in height, which is this phenomenon, is noticeable. Specifically, in the region close to the cathode electrode of the electroplating apparatus, the electric field strength is high and the plating growth rate is high, so that the post electrode is high, and in other regions where the electrolytic strength is low, the plating growth rate is low. The electrode tends to be low. When the mold resin is thickened to cover the high post electrode, the stress generated in the mold resin is increased and the amount of warpage of the wafer is increased. On the other hand, if the mold resin is formed with a film thickness equal to or smaller than that of the post electrode in order to suppress the amount of warpage of the wafer, for example, in the case of printing resin sealing with a liquid resin, the squeegee comes into contact with the post electrode, and the post electrode falls or breaks To do. Further, in the case of resin sealing with a molding resin, there is a problem that the yield of the wafer decreases due to defective wafer cracking due to contact between the mold and the post electrode.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor device and a semiconductor device with a low occurrence frequency of defective products.

  A method of manufacturing a semiconductor device according to the present invention includes a step of forming a first resist having a plurality of first openings on a plurality of wirings on a substrate having a plurality of wirings, and an electrolytic plating process. A step of forming a plurality of first electrodes corresponding to the first opening, and a first surface of the plurality of first electrodes having a height not higher than a first predetermined value as a top surface. A step of forming a second resist having a second opening on the electrode on the first resist, and electrolytic plating using the second resist, the first predetermined value or less. Forming a second electrode corresponding to the second opening on the first electrode having a height position as an upper surface.

  According to another aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising: forming a first resist having a plurality of first openings on a plurality of wirings on a substrate having the plurality of wirings; Forming a plurality of first electrodes corresponding to the first openings by electrolytic plating using one resist, and a predetermined first plating growth of the plurality of first electrodes. A step of forming a second resist having a second opening on the first electrode formed at a plating growth rate equal to or lower than the first growth rate on the first resist, and using the second resist, Forming a second electrode corresponding to the second opening on the first electrode formed at a growth rate equal to or lower than the predetermined first growth rate by electrolytic plating. Features.

  A method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device in which resist masks are stacked in multiple stages and a plating process is performed on a conductive layer exposed from a substrate. By changing a part of the opening of the eye, a portion where the plating growth rate is relatively high is changed.

  A semiconductor device according to the present invention includes a substrate, a plurality of conductive members provided on the substrate, a plurality of first electrodes formed on the plurality of conductive members by electrolytic plating, and the plurality of the plurality of conductive members. A second electrode formed by electrolytic plating on the first electrode having a top surface at a height not greater than a first predetermined value of the first electrode; and the first and second electrodes And a resin that seals the first electrode including the first electrode and the second electrode including the first electrode.

  According to the present invention, since the frequency of defective post electrode products is reduced, the yield of semiconductor devices can be increased.

(A)-(e) is a schematic sectional drawing (the 1) which shows the process of the manufacturing method of the semiconductor device which concerns on the 1st Embodiment of this invention. (A)-(d) is a schematic sectional drawing (the 2) which shows the process of the manufacturing method of the semiconductor device which concerns on 1st Embodiment. (A) And (b) is principal part sectional drawing and principal part top view which show schematically the semiconductor device which concerns on 1st Embodiment. 3 is a flowchart showing steps of a method for manufacturing a semiconductor device according to the first embodiment. It is a figure which shows an example of distribution of the height of the electrode formed in the surface of the semiconductor wafer by the electroplating apparatus. It is a figure which shows the relationship between the position and height of the post electrode after 1st electrode formation, 2nd electrode formation, and 3rd electrode formation. (A) And (b) is a schematic sectional drawing which contrasts and shows the manufacturing process of the semiconductor device of a comparative example, and the manufacturing process of the semiconductor device which concerns on 1st Embodiment. (A) And (b) is a schematic sectional drawing which shows the process of the manufacturing method of the semiconductor device which concerns on the 2nd Embodiment of this invention. It is principal part sectional drawing which shows schematically the semiconductor device which concerns on 2nd Embodiment. It is a flowchart which shows the process of the manufacturing method of the semiconductor device which concerns on 2nd Embodiment. (A) And (b) is a schematic sectional drawing which compares and shows the manufacturing process of the semiconductor device of a comparative example, and the manufacturing process of the semiconductor device which concerns on 2nd Embodiment.

  A method for manufacturing a semiconductor device and a semiconductor device according to embodiments described below are characterized by a post electrode that penetrates resin in a thickness direction and a method for forming the same in WL-CSP.

<< 1 >> First Embodiment << 1-1 >> Manufacturing Method of First Embodiment FIGS. 1A to 1E are schematic cross-sectional views showing steps of a semiconductor device manufacturing method according to the first embodiment. FIGS. 2A to 2D are schematic cross-sectional views (No. 2) showing the steps of the method of manufacturing the semiconductor device according to the first embodiment. FIG. 2A shows a process following FIG. FIGS. 3A and 3B are a schematic cross-sectional view and a plan view showing the main part of the semiconductor device according to the first embodiment. FIG. 4 is a flowchart showing the steps of the semiconductor device manufacturing method according to the first embodiment.

  First, as shown in FIG. 1A, a plurality of wirings 103 as conductive members are formed on a substrate 101, for example, a semiconductor wafer 101 in a state where a wafer process is completed, with an insulating film 102 interposed therebetween. Note that the structures of the semiconductor wafer 101 and the insulating film 102 are not limited to the illustrated example. For example, other components such as other wirings, other insulating films, passivation films, and vias (VIA) may be provided on the semiconductor wafer 101. The plurality of wirings 103 are not limited to the shape and arrangement shown in the figure, and may have other shapes and arrangements.

  Next, as shown in FIG. 1B, a first dry film (first layer dry film) which is an example of a first resist is formed on the entire surface of the semiconductor wafer 101 on the semiconductor wafer 101 on which the wiring 103 is formed. Film) 104 is pasted (step S1 in FIG. 4). Next, as shown in FIG. 1B, a plurality of first openings penetrating the first dry film 104 in the thickness direction on the wiring 103 by using exposure and development processing based on a lithography technique. (First hole) 104a is formed (steps S2 and S3 in FIG. 4).

  Next, as shown in FIG. 1C, a first electrode 105, which is a columnar first-stage electrode, is formed by electrolytic plating (step S4 in FIG. 4). The first electrode 105 is usually a copper (Cu) electrode, but may be an electrode of another metal (for example, gold, palladium, etc.). At this time, the first electrode 105 is formed only in the first opening 104 a of the first dry film 104. In addition, as illustrated in FIG. 1C, the first electrode 105 is formed so that the upper surface of the first electrode 105 is lower than the upper surface of the first dry film 104.

  When a plurality of first electrodes are formed over the entire surface of the semiconductor wafer 101 by electrolytic plating, the plating growth rate differs depending on the position on the surface of the semiconductor wafer 101. There is a difference in height. For example, since the plating growth rate is high in a region where the electric field strength is close to a place where the cathode electrode of the electrolytic plating apparatus is in contact, the first electrode 105 is high, and in a region where the electrolytic strength is far from the place where the cathode electrode is in contact. Since the plating growth rate is low, the first electrode 105 tends to be low. For this reason, the plurality of first electrodes 105 includes a plurality of first electrodes 105a in the first region 131 in which the upper surface of the first electrode is at a height not more than the first predetermined value H1, It includes at least one first electrode 105b in the second region 132 where the upper surface of the electrode is at a height higher than the first predetermined value H1.

  Next, as shown in FIG. 1D, the second dry film 106 is pasted on the first dry film 104 on the semiconductor wafer 101 (step S5 in FIG. 4).

  Next, as shown in FIG. 1E, the first opening 104a is overlaid on the plurality of first electrodes 105a in the first region 131 by using exposure and development processing based on lithography technology. A second opening (second hole) 106a penetrating through the second dry film 106 in the thickness direction is formed (steps S6 and S7 in FIG. 4). The second region 132 that is a region where the second electrode 107 is not formed is, for example, one or a plurality of rectangular unit regions, and can be one or a plurality of chip regions formed on the semiconductor wafer 101. In addition, the second region 132 that is a region where the second electrode 107 is not formed may be a partial region in one chip.

  Next, as shown in FIG. 2A, a second electrode 107, which is a second-stage electrode, is formed on the first electrode 105a in the first region 131 by electrolytic plating (see FIG. 4). Step S8). The second electrode 107 is usually a Cu electrode, but can be another metal electrode (eg, gold, palladium, etc.). In the first embodiment, a columnar structure in which the first electrode 105 a and the second electrode 107 are overlapped is the post electrode 108. At this time, the second electrode 107 is formed in the second opening 106 a of the second dry film 106. Note that the post electrode 108 has a two-stage configuration as a final structure, and when a plurality of post electrodes 108 are formed on the semiconductor wafer 101, a position far from the place where the cathode electrode of the electrolytic plating apparatus contacts (for example, a semiconductor wafer). 101 (near the center of 101) may have a different plating growth rate at a position close to (for example, the peripheral portion of the semiconductor wafer 101), but the top of some or all of the second electrodes 107 may be You may form so that it may become higher than an upper surface.

  However, in the case where three or more layers of dry films are used, the upper surface of the second electrode 107 is formed lower than the upper surface of the second dry film 106 in the same manner as the first electrode 105.

  Next, as shown in FIG. 2B, the second and first dry films 106 and 104 are removed by chemical treatment or the like (step S9 in FIG. 4).

  Next, if necessary, a component (for example, 112 in FIG. 3) is mounted on the wiring 103 (step S10 in FIG. 4). The component 112 is a light emitting element, a light receiving element, or a chip or packaged electronic component such as an oscillation element or a sensor, and the type and quantity thereof are not limited. The component 112 is selected so that the upper surface of the mounted component 112 is lower than the upper surface of the lowest post electrode 108. In other words, it is necessary to select the height of the post electrode 108 (the number of stages of electrodes to be stacked) so that the height of the post electrode 108 is higher than the upper surface of the component 112 to be mounted. It is possible to increase the height of the post electrode 108 by increasing the number of dry films to be laminated. Note that when a functional element is formed in the semiconductor wafer 101, the component 112 may not be mounted on the wiring 103.

  Thereafter, as shown in FIG. 2C, the entire surface of the semiconductor wafer 101 is sealed with a resin 109 (step S11 in FIG. 4).

  Next, as shown in FIG. 2D, in the semiconductor wafer 101 that has been sealed with the resin 109, the resin 109 is ground to expose the post electrode 108 (step S12 in FIG. 4). The height of the post electrode 108 after grinding is formed such that the top of the post electrode 108 is higher than the top of the component 112. Examples of the resin 109 include printing sealing with a molding sealing resin or a liquid (paste) resin.

  Thereafter, a solder paste is printed on the post electrode 108 and reflow processing is performed to form a hemispherical solder terminal (step S13 in FIG. 4). Through the above steps, a semiconductor device in which a component is mounted on a wiring and the component is sealed with a resin is completed in the WL-CSP.

  When forming a post electrode by stacking resist masks in multiple stages, do not provide an opening in the second stage of the second resist mask in a region where electrolytic concentration occurs in the first stage of the resist mask. Thus, the electrolytic concentration location of the first-stage resist mask and the electrolytic concentration location of the second-stage resist mask are arbitrarily moved (that is, set to an arbitrary position). That is, the plating growth rate of the first-stage electrode formed by electrolytic plating with the first-stage resist mask is high, and the plating growth of the second-stage electrode formed by electrolytic plating with the second-stage resist mask. Change the part where the speed is high. In other words, when the post electrodes are formed by stacking resist masks in multiple stages, the position of the opening of the first resist mask and the position and part of the opening of the second resist mask are changed. The location where the plating growth rate is relatively high is changed.

<< 1-2 >> Semiconductor Device of First Embodiment As shown in FIG. 2D or FIG. 3, the semiconductor device according to the first embodiment includes a semiconductor wafer 101 and a semiconductor wafer 101 on, for example, A plurality of wirings 103 provided via the insulating film 102, a plurality of first electrodes 105 formed on the plurality of wirings 103 by electrolytic plating, and a first of the plurality of first electrodes 105 The second electrode 107 formed by electrolytic plating and the first electrode 105 are sealed on the first electrode 105a whose upper surface is a position having a height equal to or less than a predetermined value H1, and the second electrode And a resin 109 that seals the side surface of the electrode 107. The stacked first electrode 105 a and second electrode 107 constitute a post electrode 108 whose upper surface is exposed from the resin 109, and the first electrode 105 b on which the second electrode 107 is not stacked is sealed with the resin 109. Has been.

<< 1-3 >> Effects of the First Embodiment The first electrode 105 and the second electrode 107 formed by electrolytic plating are in contact with the outer peripheral side of the semiconductor wafer 101, in particular, the cathode electrode 143 of the electrolytic plating apparatus. The vicinity of the place has a characteristic of rapidly increasing, and the variation in the height of the post electrode in the surface of the semiconductor wafer 101 is increased. FIG. 5 is a diagram schematically showing an example of the height distribution of the electrodes formed on the surface of the semiconductor wafer by the electrolytic plating apparatus. FIG. 6 is a diagram showing the relationship between the position and height of the post electrode after forming the first electrode, after forming the second electrode, and after forming the third electrode. FIG. 7B is a schematic cross-sectional view showing a comparison of the manufacturing process of the semiconductor device of the comparative example and the manufacturing process of the semiconductor device according to the first embodiment. In FIG. 5, a region where the electric field concentration is small (white) is indicated by 140a, a region where the electric field concentration is intermediate (thin hatched region) is indicated by 140b, and a region where the electric field concentration is high (thick line hatching region) is indicated by 140c. Yes. As shown in FIG. 5, the plating growth rate is locally high in the vicinity of the place where the cathode electrode 143 with high electrolytic strength comes into contact. Therefore, when the present invention is not applied, FIG. 6 and FIG. ), The difference D0 between the highest post electrode and the lowest post electrode is very large. In this case, if the resin is thickened in accordance with the highest post electrode, the stress generated in the resin is increased, and the amount of warpage of the wafer is increased. On the other hand, if the resin is formed with a film thickness equal to or smaller than that of the post electrode in order to suppress the amount of warpage of the wafer, for example, in the case of printing resin sealing with a liquid resin, the squeegee comes into contact with the post electrode, and the post electrode falls or breaks. To do. In the case of resin sealing with molding resin, the frequency of occurrence of wafer cracking increases due to the contact between the mold and the post electrode, and the yield decreases.

  More specifically, the height of the post electrode (Cu post) of the existing WL-CSP is about 50 to 120 μm, but the height of the post electrode is 250 μm or more in the WL-CSP for component mounting. Sometimes. For this reason, a dry film and an electrode are laminated to form a post electrode having a thickness of 250 μm or more. However, each time an electrode is laminated, the variation in the height of the post electrode in the plane of the semiconductor wafer increases. FIG. 6 shows the surface of the semiconductor wafer 101 when the first electrode (one-stage Cu post), the second electrode (two-stage Cu post), and the third electrode (three-stage Cu post) are stacked. The height variation of the post electrode inside is shown. As can be seen from FIG. 6, the maximum variation in the height of one-stage Cu post (first electrode) is about 10 μm, but the two-stage Cu post (first electrode and second electrode 2) The height variation of the step) is about 20 μm at the maximum, and the height variation of the three-stage Cu post (the first electrode, the second electrode, and the third electrode) is about 35 μm at the maximum. . The resin 109 needs to be thicker than the highest post electrode, and the stress caused by the increase in the resin film thickness increases the amount of warpage of the wafer. Is likely to occur.

  FIG. 7A shows a maximum value D0 of height variation (maximum value of height difference) D0 of the plurality of post electrodes manufactured by the manufacturing process of the semiconductor device of the comparative example. (B) shows a maximum value (maximum value of height difference) D1 of the variation in height of the plurality of post electrodes manufactured by the manufacturing process of the semiconductor device according to the first embodiment. As shown in FIG. 7A as a comparative example, when the post electrode 107a is formed in the region 132a close to the place where the cathode electrode (143 in FIG. 5) of the electrolytic plating apparatus is in contact, FIG. The maximum value D0 of the post electrode height variation shown in FIG. In contrast, according to the semiconductor device manufacturing method of the first embodiment, as shown in FIG. 7B, the difference between the highest post electrode and the lowest post electrode (the height of the plurality of post electrodes). The maximum value of the variation (D1) is much smaller than the difference D0 shown in FIG. 7A when the post is formed in the region 132a. That is, compared to a region far from the place where the cathode electrode 143 of the plating apparatus is in contact, a phenomenon in which the height of the post electrode near the place where the cathode electrode 143 of the plating apparatus is in contact is suppressed, so that the post electrode is covered. The resin can be thinly formed, the amount of warpage of the semiconductor wafer 101 due to the stress generated in the resin can be suppressed, and problems in subsequent semiconductor wafer processing can be made difficult to occur.

  In the first embodiment, the first electrode 105 is formed using the first dry film 104 as a mask for electrolytic plating treatment, and then the second electrode 107 is formed using the second dry film 106. By forming, the post electrode 108 having a high height is formed. As described above, by dividing the formation process of the post electrode 108 into two times, it becomes possible to reduce the aspect ratio of the dry film in the electrolytic plating process of the post electrode 108, and the component mounting can be performed without generating a cavity inside the post electrode 108. It is possible to secure the post electrode height necessary for the above.

  In addition, by making the height of the upper portion of the first electrode 105 using the first dry film 104 as a mask lower than the upper surface of the first dry film 104, adhesion when the second dry film 106 is attached. Jumping out of the first electrode 105 that causes a decrease can be suppressed.

  Furthermore, the development of the first dry film 104 tends to widen the pattern top. As a result, the position of the interface between the first dry film 104 and the second dry film 106, and the outer peripheral surface of the post electrode 108, as shown in FIGS. 3A and 3B, A long annular outer peripheral projection (step) 110 is formed. The protrusion 110 can prevent the post electrode 108 from being removed from the resin 109.

  Furthermore, in the first embodiment, the joint (bonding position) 111 between the first electrode 105a and the second electrode 107 is the interface between the first dry film 104 and the second dry film 106, which is a stress concentration location. (At this interface position, an annular outer circumferential protrusion (step) 110 that is long in the circumferential direction as shown in FIGS. 3A and 3B is formed). The strength of the post electrode can be increased by making the joining position and the stress concentration location different. Further, the post electrode step 110 generated at the interface between the first dry film 104 and the second dry film 106 can prevent the post electrode from coming off from the resin 109.

  Note that the second region 132 can grasp and determine in advance a region where the plating rate rapidly increases for each electrolytic plating condition.

<< 2 >> Second Embodiment << 2-1 >> Manufacturing Method of Second Embodiment FIGS. 8A and 8B are schematic cross-sectional views showing steps of a method of manufacturing a semiconductor device according to the second embodiment. FIG. 9 is a schematic cross-sectional view showing the main part of the semiconductor device according to the second embodiment. In the second embodiment, reference is also made to FIGS. 1A to 1E and FIG. 2A showing processes common to the first embodiment. FIG. 8A showing the second embodiment is the next step of FIG. In the second embodiment, the areas 131 and 132 in FIGS. 1A to 1E and 2A are read as areas 231 and 232. FIG. 10 is a flowchart showing the steps of the semiconductor device manufacturing method according to the second embodiment. In the second embodiment, the post electrode 208 has a stacked structure of three-stage electrodes including the first electrode 105, the second electrode 107, and the third electrode 207. This is different from the first embodiment having a laminated structure of electrodes. The present invention can also be applied to the formation of a post electrode having a laminated structure of four or more electrodes.

  In the method for manufacturing a semiconductor device according to the second embodiment, the semiconductor wafer used for manufacturing the semiconductor device according to the second embodiment is started before the process for forming the post electrode 208 on the semiconductor wafer 101 is started. Using a measurement semiconductor wafer and a photoresist having the same structure as 101, a semiconductor wafer in which the upper surface of the first electrode 105 is at a height not higher than a first predetermined value (H1 in FIG. 8A). 101 and the second region 232 on the semiconductor wafer 101 where the upper surface of the first electrode 105 is at a height exceeding the first predetermined value (H1 in FIG. 8A). To detect. In the method for manufacturing a semiconductor device according to the second embodiment, using this detection result, the second opening 106 a of the second dry film 106 is formed in the first region 231 and the second region 232 is opened. No part is formed (steps S5 to S7 in FIG. 10).

  In the method for manufacturing a semiconductor device according to the second embodiment, a measurement semiconductor wafer and a photoresist having the same structure as the semiconductor wafer 101 used for manufacturing the semiconductor device according to the second embodiment are used. The third region 234 on the semiconductor wafer 101 where the upper surface of the second electrode 107 is at a height not more than a second predetermined value (H2 in FIG. 8A) and the upper surface of the second electrode 107 are A fourth region 233 on the semiconductor wafer 101 at a position exceeding the second predetermined value (H2 in FIG. 8A) is detected. In the manufacturing method of the semiconductor device according to the second embodiment, using this detection result, the third opening 206a of the third dry film 206 is formed in the third region 234, and the opening is formed in the fourth region 233. No part is formed (steps S21 to S23 in FIG. 10). By using the method for manufacturing a semiconductor device according to the second embodiment, the variation in the height of the post electrode 208 can be reduced, so that the occurrence frequency of defective post electrodes can be reduced.

  As in the case of the first embodiment, a plurality of wirings 103 are formed on the semiconductor wafer 101 via the insulating film 102, and the first dry film 104 is attached (step S1 in FIG. 10). A plurality of first openings 104a penetrating the first dry film 104 in the thickness direction are formed (steps S2 and S3 in FIG. 10), and the first electrode as the first stage electrode is formed by electrolytic plating. The electrode 105 is formed (step S4 in FIG. 10).

  Next, as in the case of the first embodiment, the second dry film 106 is attached (step S5 in FIG. 10), and the second dry film 106 is penetrated in the thickness direction on the first region 231. A plurality of second openings 106a are formed (steps S6 and S7 in FIG. 10), and the second electrode 107, which is the second stage electrode, is formed by electrolytic plating (step S8 in FIG. 10).

  Next, the 3rd dry film 206 is affixed on the 2nd dry film 106 (step S21 in FIG. 10). Next, as shown in FIG. 8A, the second opening 106a is overlaid on the plurality of second electrodes 107 in the third region 234 by using exposure and development processing based on lithography technology. A third opening (third hole) 206a penetrating the third dry film 206 in the thickness direction is formed (steps S22 and S23 in FIG. 10). The fourth region 233 which is a region where the third electrode 207 is not formed is, for example, one or a plurality of rectangular unit regions, and can be a region of one or a plurality of chips formed on the semiconductor wafer 101. The fourth region 233, which is a region where the third electrode 207 is not formed, may be a partial region in one chip.

  Next, as shown in FIG. 8B, a third electrode 207, which is a third-stage electrode, is formed on the second electrode 107 in the third region 234 by electrolytic plating (step in FIG. 10). S24). The third electrode 207 is usually a Cu electrode, but can be another metal electrode (eg, gold, palladium, etc.). In the second embodiment, the post electrode 208 is a columnar structure in which the first electrode 105 a, the second electrode 107, and the third electrode 207 are overlapped. At this time, the third electrode 207 is formed in the third opening 206 a of the third dry film 206. Note that the post electrode 208 has a three-stage configuration as the final structure, and when a plurality of post electrodes 208 are formed on the semiconductor wafer 101, a position far from the place where the cathode electrode 143 of the electrolytic plating apparatus contacts (for example, a semiconductor Although the plating growth rate at a position close to the vicinity of the center of the wafer 101 (for example, the peripheral portion of the semiconductor wafer 101) may be different, the top of a part or all of the third electrodes 207 is the third dry film 206. You may form so that it may become higher than the upper surface of.

  However, in the case where four or more layers of dry films are used, the upper surface of the third electrode 207 is formed lower than the upper surface of the third dry film 206 in the same manner as the first and second electrodes 105 and 107. To do.

  Next, the third, second, and first dry films 206, 106, and 104 are removed by chemical treatment or the like (step S9 in FIG. 10), and components (for example, FIG. 9) are formed on the wiring 103 as necessary. 112) is implemented (step S10 in FIG. 10). The component 112 is selected so that the upper surface of the mounted component 112 is positioned lower than the upper surface of the lowest post electrode 208. Note that the component 112 may not be mounted on the wiring 103.

  Thereafter, the entire surface of the semiconductor wafer 101 is sealed with the resin 209 (step S11 in FIG. 10), the resin 209 is ground, and the post electrode 208 is exposed (step S12 in FIG. 10). The post electrode 208 after grinding is formed such that the top of the post electrode 208 is positioned higher than the top of the component 112.

  Thereafter, a solder paste is printed on the post electrode 208 and reflow processing is performed to form a hemispherical solder terminal (step S13 in FIG. 10). Through the above steps, a semiconductor device in which a component is mounted on a wiring and the component is sealed with a resin 209 is completed in the WL-CSP.

  When forming a post electrode by stacking resist masks in multiple stages, the second stage resist mask has a second stage opening in a region where electrolytic concentration occurs in the first stage opening of the first stage resist mask. The first-stage resist mask is not provided by providing the third-stage opening of the third-stage resist mask in the region where the electrolytic concentration of the second-stage opening of the second-stage resist mask occurs. The electrolytic concentration point of the second step, the electrolytic concentration point of the second-stage resist mask, and the electrolytic concentration point of the third-stage resist mask are arbitrarily moved (that is, set to an arbitrary position). That is, the plating growth rate of the first-stage electrode formed by electrolytic plating with the first-stage resist mask is high, and the plating growth of the second-stage electrode formed by electrolytic plating with the second-stage resist mask. A location where the speed is high and a location where the plating growth rate of the third-stage electrode formed by electrolytic plating with the third-stage resist mask is high are changed (that is, set at an arbitrary position). In other words, when the post electrodes are formed by laminating resist masks in multiple stages, the plating growth rate is relatively high by changing part of the openings in the first and other stages of the resist mask. To change.

  As illustrated in FIG. 9, the semiconductor device according to the second embodiment includes a semiconductor wafer 101, a plurality of wirings 103 provided on the semiconductor wafer 101 via, for example, an insulating film 102, and a plurality of wirings. A plurality of first electrodes 105 formed by electrolytic plating on the first electrode 103 and a first electrode having a top surface at a height not higher than a first predetermined value H1 among the plurality of first electrodes 105; A second electrode 107 formed by electrolytic plating on 105a and a first surface of a plurality of second electrodes 107 having a height equal to or lower than a second predetermined value H2 (H2> H1). A resin 209 that seals the third electrode 207 formed by electrolytic plating on the second electrode 107, the first electrode 105, and the second electrode 107, and seals the side surface of the third electrode 207. And have. As shown in FIG. 9, the stacked first electrode 105a, second electrode 107, and third electrode 207 constitute a post electrode 208 whose upper surface is exposed from the resin 209, and FIG. Although not shown, as shown in FIG. 8B, the first electrode 105b and the second electrode 107b on which the third electrode 207 is not stacked are sealed with a resin 209.

<< 2-2 >> Effect of Second Embodiment FIG. 11A shows the maximum value of the height variation (the difference in height) of the plurality of post electrodes manufactured by the manufacturing process of the semiconductor device of the comparative example. The maximum value) D10 is shown, and FIG. 11B shows the maximum value (height of the height variation of the plurality of post electrodes manufactured by the manufacturing process of the semiconductor device according to the second embodiment. The maximum difference) D11 is shown. As shown in FIG. 11A as a comparative example, when the post electrode 207a is formed in the region 233a close to the place where the cathode electrode (143 in FIG. 5) of the electrolytic plating apparatus is in contact, FIG. The maximum value D10 of the post electrode height variation shown in FIG. On the other hand, according to the semiconductor device manufacturing method according to the second embodiment, as shown in FIG. 11B, the difference between the highest post electrode and the lowest post electrode (the height of the plurality of post electrodes). The maximum variation D11) is much smaller than the difference D10 shown in FIG. 11A when a post is formed in the region 233a. That is, since the phenomenon that the height of the post electrode is increased near the place where the cathode electrode 143 of the electroplating apparatus is in contact with the area far from the place where the cathode electrode 143 of the electroplating apparatus is in contact is suppressed. It is possible to form a thin resin for coating the semiconductor wafer 101, suppress the amount of warping of the semiconductor wafer 101 due to the stress generated in the resin, and make it difficult to cause problems in subsequent semiconductor wafer processing.

  The development of the first dry film 104 and the second dry film 106 has a tendency to widen the pattern top. As a result, the interface between the first dry film 104 and the second dry film 106 has annular outer circumferential protrusions (steps) 110 and 210 that are long in the circumferential direction as shown in FIG. The protrusions 110 and 210 have an effect of preventing the post electrode from coming off from the resin 209.

  In addition, according to the second embodiment, the formation process of the post electrode 208 is divided into three times by forming the high post electrode by dividing the dry film pasting and post electrode plating process into three times. Since it is possible to reduce the aspect ratio of the dry film in the 208 electrolytic plating process, even if an inexpensive device is used, the height of the post electrode necessary for component mounting is secured without creating a cavity inside the post electrode. can do.

  Furthermore, in the second embodiment, the joint (bonding position) 111 between the first electrode 105a and the second electrode 107 is formed at the interface between the first dry film 104 and the second dry film 106, which is a stress concentration location. (At this interface position, an annular outer circumferential protrusion (step) 110 is formed that is long in the circumferential direction as shown in FIG. 9), and the joint between the second electrode 107 and the third electrode 207 is formed. (Bonding position) 211 is an interface between the second dry film 106 and the third dry film 206, which is a stress concentration point (this interface position has an annular outer circumferential protrusion that is long in the circumferential direction as shown in FIG. Part (step) 210 is formed). The strength of the post electrode can be increased by making the joining position and the stress concentration location different. Further, the post electrode step 110 generated at the interface between the first dry film 104 and the second dry film 106 and the post electrode step 210 generated at the interface between the second dry film 106 and the third dry film 206 It is possible to suppress the post electrode from coming off from the resin 209.

  In addition, the areas 232 and 233 can grasp and determine in advance an area where the plating rate rapidly increases for each electrolytic plating condition.

  DESCRIPTION OF SYMBOLS 101 Semiconductor wafer, 102 Insulating film, 103 Wiring, 104 1st dry film (1st resist), 104a 1st opening part (hole), 105, 105a, 105b 1st electrode, 106 2nd dry film (Second resist), 106a second opening (hole), 107 second electrode, 108,208 post electrode, 109,209 resin, 112 parts, 110,210 outer peripheral projection, 111,211 bonding position, 131, 231 First region, 132, 232 Second region, 143 Cathode electrode, 206 Third dry film (third resist), 206a Third opening (hole), 207 Third electrode, 234 Third Region, 233 fourth region.

Claims (18)

Forming a first resist having a plurality of first openings on the plurality of wirings on a substrate having a plurality of wirings;
Forming a plurality of first electrodes corresponding to the first openings by electrolytic plating;
A second resist having a second opening on the first electrode having a top surface at a height of a first predetermined value or less among the plurality of first electrodes is formed on the first resist. Forming the step,
A second electrode corresponding to the second opening is formed on the first electrode having the upper surface at a position having a height equal to or lower than the first predetermined value by electrolytic plating using the second resist. A method of manufacturing a semiconductor device, comprising: forming an electrode. A third resist having a third opening on the second electrode having a top surface at a height of a second predetermined value or less among the plurality of second electrodes is formed on the second resist. Forming the step,
A third electrode corresponding to the third opening is formed on the second electrode having the upper surface at a position having a height equal to or lower than the second predetermined value by electrolytic plating using the third resist. The method of manufacturing a semiconductor device according to claim 1, further comprising: forming an electrode.   Before starting the formation of the first electrode, the semiconductor wafer for measurement is used to detect a region where the upper surface of the first electrode is at a height not more than the first predetermined value. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the step of forming the second resist is executed using the result. 4. Forming a first resist having a plurality of first openings on the plurality of wirings on a substrate having a plurality of wirings;
Forming a plurality of first electrodes corresponding to the first openings by electrolytic plating using the first resist;
A second resist having a second opening on the first electrode formed at a plating growth rate equal to or lower than a predetermined first plating growth rate among the plurality of first electrodes; Forming on the resist;
A second electrode corresponding to the second opening on the first electrode formed at a growth rate lower than the predetermined first growth rate by electrolytic plating using the second resist. And a method of manufacturing a semiconductor device. A third resist having a third opening is formed on the second electrode formed at a plating growth rate equal to or lower than a predetermined second plating growth rate among the plurality of second electrodes. Forming on the resist;
A third electrode corresponding to the third opening is formed on the second electrode formed at a plating growth rate equal to or lower than the predetermined second plating growth rate by electrolytic plating using the third resist. The method of manufacturing a semiconductor device according to claim 4, further comprising: forming an electrode. The step of forming the first resist includes the step of attaching a first photoresist dry film on the substrate, and the first opening that penetrates the first photoresist dry film in the thickness direction. Forming a process,
The step of forming the second resist includes the step of attaching a second photoresist dry film on the first resist, and the second opening penetrating the second photoresist dry film in the thickness direction. The method of manufacturing a semiconductor device according to claim 1, further comprising: forming a portion.   The step of forming the third resist includes the step of attaching a third photoresist dry film on the second resist, and the third opening penetrating the third photoresist dry film in the thickness direction. The method for manufacturing a semiconductor device according to claim 2, further comprising a step of forming a portion. Removing the second resist and the first resist;
Sealing a post electrode composed of the first electrode and the second electrode with a resin;
The method for manufacturing a semiconductor device according to claim 1, further comprising a step of grinding the structure sealed with the resin by grinding.   The method further comprises a step of mounting an electronic component on the substrate after the step of removing the second resist and the first resist and before the step of sealing with the resin. A method for manufacturing a semiconductor device according to claim 8. Removing the third resist, the second resist and the first resist;
Sealing a post electrode composed of the first electrode, the second electrode, and the third electrode with a resin;
The method for manufacturing a semiconductor device according to claim 2, further comprising: grinding the structure sealed with the resin by grinding.   The method further includes a step of mounting an electronic component on the substrate after the step of removing the third resist, the second resist, and the first resist and before the step of sealing with the resin. The method of manufacturing a semiconductor device according to claim 10.   2. The step of forming the first electrode, wherein the first electrode is formed such that an upper surface of the first electrode is lower than an upper surface of the first resist. 12. A method for manufacturing a semiconductor device according to any one of items 11 to 11.   3. The step of forming the second electrode, wherein the second electrode is formed so that an upper surface of the second electrode is lower than an upper surface of the second resist. The manufacturing method of the semiconductor device of description. A method of manufacturing a semiconductor device in which resist masks are stacked in multiple stages and plating is performed on a conductive layer exposed from a substrate,
A method of manufacturing a semiconductor device, wherein a portion having a relatively high plating growth rate is changed by changing a part of the opening of the first step and the other step of the resist mask. A substrate,
A plurality of conductive members provided on the substrate;
A plurality of first electrodes formed by electrolytic plating on the plurality of conductive members;
A second electrode formed by electrolytic plating on the first electrode having a top surface at a height not higher than a first predetermined value among the plurality of first electrodes;
A semiconductor device comprising: a first post electrode including the first electrode and the second electrode; and a resin that seals the second electrode including the first electrode.   A side surface of the first post electrode is formed with a first outer circumferential protrusion that is longer in the circumferential direction at a position higher than a bonding position between the first electrode and the second electrode. The semiconductor device according to claim 15.   16. The semiconductor device according to claim 15, further comprising an electronic component sealed with the resin. A third electrode formed by electrolytic plating is provided on the second electrode having a top surface at a height not higher than a second predetermined value among the plurality of second electrodes,
The semiconductor device according to claim 15, wherein the first post electrode sealed with the resin includes the third electrode.

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