JP2016138918A - Method for manufacturing semiconductor device, and photomask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device, by which a residue of a negative photoresist film can be suppressed.SOLUTION: The method for manufacturing a semiconductor device includes: a step of forming a negative photoresist film on a semiconductor substrate having a first region having conductive pads arranged at a first pitch and a second region having a longer dimension in at least one direction than the first pitch; and a step of irradiating the negative photoresist film with exposure light through a first photomask 20a that has a plurality of bump patterns 16 arranged in a third region 8c corresponding to the first region and corresponding to the conductive pads, and a first additional pattern 18a disposed in a fourth region 8d corresponding to the second region and having a width smaller than a width of the bump pattern 16.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing a semiconductor device and a photomask.

  A dry film resist (Dry Film Photoresist) is a film-like negative photoresist film used for forming electrodes on a semiconductor substrate (for example, Patent Document 1). In electrode formation using a dry film resist, first, a dry film resist is laminated on the upper surface of a wiring layer formed on a semiconductor substrate. Next, an opening is provided in the dry film resist, and an electrode is formed in the opening. Thereafter, the dry film resist is removed to complete the electrode.

  Residue problems have been reported for electrode formation using dry film resists. Specifically, when the distance between the electrodes becomes narrow, the dry film resist residue is sandwiched between the electrodes and cannot be removed. As a result, the yield of the semiconductor device is reduced. As a method for suppressing the generation of such a residue, a technique has been proposed in which a recess is provided on the side surface of an electrode to widen a gap between the electrodes (for example, Patent Document 1).

JP 2012-74538 A

  In addition to the problems described above, the dry film resist has a problem that a residue is generated in an empty area on the substrate surface where no electrode group is arranged. The dry film resist is a negative photoresist film.

  In order to solve the above problem, according to one aspect of the present manufacturing method, a first region having conductive pads arranged at a first pitch and a length longer than the first pitch in at least one direction. Forming a negative photoresist film on a semiconductor substrate having two regions, a plurality of bump patterns disposed in a third region corresponding to the first region and corresponding to the conductive pad, and the second Irradiating the negative photoresist film with exposure light through a first photomask having a first additional pattern disposed in a fourth region corresponding to the region and having a width smaller than that of the bump pattern; After the step of irradiating the exposure light, developing the negative photoresist film to form an opening corresponding to the bump pattern in the negative photoresist film; and Forming a conductive electrode, after formation of the electrode, a method of manufacturing a semiconductor device and a step of removing the negative photoresist film is provided.

  According to the disclosed method, it is possible to suppress a residue of a negative photoresist film that occurs in an empty area where no electrode group is disposed.

FIG. 1 is a process cross-sectional view illustrating the method for manufacturing the semiconductor device of the first embodiment. FIG. 2 is a process cross-sectional view illustrating the method for manufacturing the semiconductor device of the first embodiment. FIG. 3 is a process cross-sectional view illustrating the method for manufacturing the semiconductor device of the first embodiment. FIG. 4 is a process cross-sectional view illustrating the method for manufacturing the semiconductor device of the first embodiment. FIG. 5 is an example of a plan view of a semiconductor substrate on which conductive pads are formed. FIG. 6 is a diagram illustrating an example of the first photomask. FIG. 7 is a diagram for explaining the width of the pattern. FIG. 8 is a diagram for explaining the reason why the opening corresponding to the first additional pattern is not formed. FIG. 9 is a diagram for explaining a mechanism for generating a residue of a negative photoresist film. FIG. 10 is a diagram illustrating the second photomask. FIG. 11 is a partially enlarged view of the second additional pattern. FIG. 12 is a plan view illustrating an example of the photomask of Embodiment 3. FIG. 13 is an enlarged view of region C shown in FIG. FIG. 14 is a diagram illustrating an example of an additional pattern arranged in the outer edge region instead of the third additional pattern. FIG. 15 is a plan view illustrating an example of the photomask of Embodiment 4.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof. Note that, even if the drawings are different, corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

(Embodiment 1)
(1) Manufacturing Method FIGS. 1 to 4 are process cross-sectional views illustrating a method for manufacturing the semiconductor device of the first embodiment.

(1-1) Previous process (see FIG. 1 (a))
First, the integrated circuit 30 is formed on the semiconductor substrate 12 (for example, Si substrate).

  Specifically, a device such as a transistor (not shown) is formed on the surface of the semiconductor substrate 12, and then a wiring layer 32 is formed on the semiconductor substrate 12. The wiring layer 32 is, for example, a layer having an interlayer insulating film and wiring (including vias) formed in the interlayer insulating film. The wiring formed in the interlayer insulating film is connected to a device formed on the semiconductor substrate.

  Terminals 34 (for example, Al pads) are formed in the uppermost interlayer insulating film. For example, the terminal 34 is an external terminal of the integrated circuit 30. Further, a cover film 36 (for example, a SiN film) that covers a portion not covered with the terminal 34 and an outer peripheral portion of the terminal 34 is formed on the uppermost interlayer insulating film. In FIG. 1A, a portion of the cover film 36 that covers the outer peripheral portion of the terminal 34 is omitted.

(1-2) Step of forming conductive pad (see FIGS. 1B to 3A)
Next, a conductive pad is formed on the semiconductor substrate 12 on which the integrated circuit 30 is formed. The conductive pad is, for example, UBM (under bump metal).

  FIG. 1B to FIG. 3A are diagrams for explaining an example of a conductive pad forming process. First, for example, polyimide 38 is applied on the wiring layer 32 (see FIG. 1B) where the terminals 34 are formed. The polyimide 38 is a negative photosensitive material.

  As shown in FIG. 1C, the polyimide 38 is irradiated with exposure light 42a through a photomask (reticle) 40a. By this irradiation, a portion of the polyimide 38 covering the center of the terminal 34 is exposed.

  In FIG. 1C, only the light shielding film (for example, Cr film) of the photomask 40a is shown, and the substrate (for example, quartz plate) of the photomask 40a is omitted. The same applies to other photomasks (reticles) described later.

  After irradiation with the exposure light 42a, the polyimide 38 is developed to form an opening 44a in the polyimide 38 that exposes the central portion of the terminal 34, as shown in FIG. After the development of the polyimide 38, the polyimide 38 is heated and cured. By this curing, the polyimide 38 becomes slightly thin.

  Thereafter, a seed layer (not shown) is formed on the semiconductor substrate 12 in which the opening 44a is formed, for example, by sputtering. The seed layer is, for example, a laminated film of a Ti film and a Cu film.

  A photoresist 46 is applied on the semiconductor substrate 12 (see FIG. 2A) on which the seed layer is formed. The photoresist 46 is, for example, a positive type photoresist.

  The photoresist 46 is irradiated with exposure light 42b through a photomask 40b (see FIG. 2B). By this irradiation, a portion of the photoresist 46 that covers the central portion of the terminal 34 and the vicinity of the portion are exposed.

  After the exposure light 42b is irradiated, the photoresist 46 is developed to form an opening 44b in the photoresist 46 that exposes the central portion of the terminal 34 and the vicinity of the central portion, as shown in FIG.

  Next, as shown in FIG. 2D, the conductive pad 6 is formed in the opening 44b by electrolytic plating using the seed layer as a cathode described above. The conductive pad 6 is connected to the integrated circuit 30 of the semiconductor substrate 12 through the terminal 34. The conductive pad 6 is, for example, a Ni layer whose surface is covered with Au. The conductive pad 6 may be a Cu layer.

  Thereafter, the photoresist 46 is removed by, for example, a resist stripping solution (see FIG. 3A). Further, the seed layer is removed by wet etching, for example, using the plating layer as a mask.

  FIG. 5 is an example of a plan view of the semiconductor substrate 12 on which the conductive pads 6 are formed. The semiconductor substrate 12 on which the conductive pads 6 are formed has a chip region 10 corresponding to a semiconductor chip (die) and a dicing line 11. The chip region 10 includes a first region 8a having conductive pads 6 arranged at a first pitch 4a in the first direction 2a and further arranged at a third pitch 4c in a third direction 2c different from the first direction 2a. Including. The first direction 2a is, for example, a direction orthogonal to the third direction 2c.

  The chip region 10 further has a dimension W0 longer than any of the first pitch 4a and the third pitch 4c in at least one direction (the third direction 2c in the example shown in FIG. 1) of the first direction 2a and the third direction 2c. The second region 8b is included. The second region 8b may have a dimension longer than both the first pitch 4a and the third pitch 4c in a plurality of directions.

  The pitches 4a and 4c of the conductive pads 6 are, for example, 100 μm or more and 400 μm or less (or 150 μm or more and 300 μm). The width of the conductive pad 6 is, for example, 50 μm or more and 300 μm or less (or 100 μm or more and 200 μm or less). One side of the second region 8b is, for example, 200 μm or more (or 250 μm or more).

  An example of the pitch (period) of the conductive pads 6 is, for example, 200 μm. An example of the width of the conductive pad 6 is 150 μm, for example. An example of the second region 8b is a rectangular region having a short side of 275 μm and a long side of 350 μm, for example.

  In addition, the broken line of FIG. 5 is a boundary of each area | region, and is not a real thing. The same applies to FIG. 6 described later.

(1-3) Formation of negative photoresist film (see FIG. 3B)
A negative photoresist film 14 (see FIG. 3B) is formed on the semiconductor substrate 12 on which the conductive pads 6 are formed. The negative photoresist film 14 is, for example, a dry film resist. The photoresist film is a film-like photoresist.

  Specifically, for example, a dry film resist having a thickness of 20 μm to 80 μm (or 40 μm to 60 μm) is laminated on the semiconductor substrate 12. Thereafter, the dry film resist and the semiconductor substrate 12 are heated at 120 ° C. to 180 ° C. (for example, 150 ° C.) to adhere the dry film resist to the semiconductor substrate 12.

(1-4) Exposure of negative photoresist film (see FIG. 3C)
The negative photoresist film 14 on the semiconductor substrate 12 is irradiated with the exposure light 22 through the first photomask 20a (see FIG. 3C). The exposure is performed by a stepper, for example. The exposure magnification is, for example, equal magnification. The exposure light 22 is, for example, ultraviolet rays including any of G line, H line, and I line.

  FIG. 6 is a diagram illustrating an example of the first photomask 20a. FIG. 6A is an example of a plan view of the first photomask 20a. FIG. 6B is an enlarged view of the region A shown in FIG.

  The first photomask 20 a has a pattern region 48 and an outer edge region 50 that extends along the outer edge of the pattern region 48. The pattern region 48 is a region corresponding to the chip region 10 (see FIG. 5) of the semiconductor substrate 12.

  The pattern region 48 includes a third region 8c and a fourth region 8d. The third region 8c is a region corresponding to the first region 8a (see FIG. 5) of the semiconductor substrate 12. The fourth region 8d is a region corresponding to the second region 8b (see FIG. 5) of the semiconductor substrate 12. The first photomask 20 a further includes a light shielding film 52 surrounding the outer edge region 50.

  The first photomask 20a has a plurality of bump patterns 16 arranged in the third region 8c. The bump pattern 16 is a pattern corresponding to the conductive pad 6 (see FIG. 5) of the semiconductor substrate 12.

  The first photomask 20a further includes a plurality of first additional patterns 18a (see FIG. 6B) arranged in the fourth region 8d. The first additional pattern 18a is a pattern having a width W2 (see FIG. 6B) narrower than the width W1 of the bump pattern 16 (see FIG. 6A). The bump pattern 16 and the first additional pattern 18a have a light shielding film and shield the exposure light 22 (the same applies to other patterns described later).

  The first additional pattern 18 a is preferably a dummy pattern that does not form an opening in the negative photoresist film 14. Accordingly, the width W2 of the first additional pattern 18a is preferably less than or equal to the resolution of the negative photoresist film 14.

-Pattern width-
FIG. 7 is a diagram for explaining the width of the pattern. The width of the pattern is a dimension W (distance) from one end to the other end of the pattern P in the short direction. However, when the pattern is a perfect circle, the width of the pattern is the diameter.

(1-5) Development process (see FIG. 3D)
The negative photoresist film 14 irradiated with the exposure light 22 is developed, and an opening 24 corresponding to the bump pattern 16 (see FIG. 6A) is formed in the negative photoresist film 14. The developer is, for example, an aqueous solution containing sodium carbonate.

  As described above, the first additional pattern 18 a is a pattern that does not form an opening in the negative photoresist film 14. Therefore, no opening corresponding to the first additional pattern 18 a is formed in the negative photoresist film 14. The same applies to the second additional pattern 18b to the fourth additional pattern 18d described later.

  FIG. 8 is a diagram for explaining the reason why the opening corresponding to the first additional pattern 18a is not formed. FIG. 8A is a view for explaining exposure in the vicinity of the bump pattern 16. FIG. 8B is a diagram illustrating exposure in the vicinity of the first additional pattern 18a.

  The exposure light 22 passing near the bump pattern 16 forms a shadow 54a on the surface of the negative photoresist film 14 as shown in FIG. Accordingly, in the region 56 immediately below the bump pattern 16, the negative photoresist film 14 hardly causes a crosslinking reaction.

  Accordingly, the region 56 is not insolubilized in the developer. As a result, the region 56 immediately below the bump pattern 16 is removed by the developer, and the opening 24 is formed.

  On the other hand, the exposure light 22 passing near the first additional pattern 18a forms a small shadow 54b on the surface of the negative photoresist film 14 as shown in FIG. 8B. A large amount of scattered light 58 of the exposure light 22 travels below the shadow 54b. Due to the scattered light 58, the exposure amount below the first additional pattern 18a easily exceeds the photosensitive threshold value (the minimum exposure amount at which the resist is not removed). As a result, the negative photoresist film 14 is insolubilized below the first additional pattern 18a, and no opening corresponding to the first additional pattern 18a is formed.

  When the first additional pattern 18a is large to some extent, the exposure amount by the scattered light 58 may not exceed the photosensitive threshold value in the vicinity of the surface of the negative photoresist film 14 in the region below the shadow 54b. In this case, a depression (a recess that does not penetrate the negative photoresist film 14) is formed on the surface of the negative photoresist film 14. As will be described later, this depression does not adversely affect the formation of the semiconductor device.

(1-6) Bump formation process (refer to Drawing 4 (a)-Drawing 4 (b))
A conductive protruding electrode 26 (see FIG. 4B) is formed in the opening 24 of the negative photoresist film 14.

  Specifically, for example, a solder paste having solder particles and flux is applied onto the negative photoresist film 14. By applying the solder paste, the opening 24 (see FIG. 3D) is filled with the solder paste. Thereafter, the solder paste on the surface of the negative photoresist film 14 is removed with a squeegee. Then, an isolated solder paste 61 is formed in the opening 24 as shown in FIG.

  The solder particles contained in the solder paste 61 are aggregated by reflow to form protruding electrodes (that is, solder bumps) 26 as shown in FIG.

(1-7) Peeling step (see FIG. 4C)
After forming the protruding electrode 26, the negative photoresist film 14 is removed.

  Specifically, for example, the negative photoresist film 14 is peeled off by immersing the semiconductor substrate 12 on which the protruding electrodes 26 are formed in a stripping solution. The stripping solution is, for example, an alkaline aqueous solution containing potassium hydroxide (or sodium hydroxide).

  The negative photoresist film 14 is removed without leaving a residue. This is because the exposure light 22 is attenuated by the first additional pattern 18a and the insolubilization of the negative photoresist film 14 is suppressed (see “(3) Residue suppression”).

  As described above, the negative photoresist film 14 may have a recess corresponding to the first additional pattern 18a. When the first additional pattern 18a is small and the dent is shallow, the solder paste is not filled in the dent. When the first additional pattern 18a is large to some extent, the dent becomes deeper and the solder paste is filled into the dent. Solder particles contained in the filled solder paste are aggregated by reflow to form a solder lump. If the solder lump is not removed from the semiconductor substrate 12, the yield of the semiconductor device is lowered.

  However, the solder paste aggregated in the recess is removed together with the negative photoresist film 14 during the peeling process. Accordingly, the depression formed by the first additional pattern 18a does not adversely affect the formation of the semiconductor device.

  Note that if a depression formed by the first additional pattern 18 a penetrates the negative photoresist film 14, a solder lump is formed on the polyimide 38. However, since the adhesion between the solder and the polyimide is poor, it is easy to remove such a lump of solder.

(1-8) Post-process First, the protruding electrode 26 is heated in a formic acid atmosphere, and the shape of the protruding electrode 26 is made close to a sphere while removing the oxide film on the surface of the protruding electrode.

  Thereafter, the semiconductor substrate 12 is cut along the dicing line 11 to form a semiconductor chip.

  Finally, the semiconductor chip is stored in a package to complete the semiconductor device. The protruding electrode 26 is, for example, an external connection terminal of the semiconductor device.

(2) First Photomask In the above description, the structure of the first photomask 20a has been described in relation to the structure of the semiconductor substrate 12 (see FIG. 5). Here, the structure of the first photomask 20a will be described regardless of the structure of the semiconductor substrate 12.

  As shown in FIG. 6A, the first photomask 20a has a plurality of bump patterns 16 arranged in the third region 8c. The bump patterns 16 are arranged at the second pitch 4b in the second direction 2b. The bump pattern 16 is further arranged at a fourth pitch 4d in a fourth direction 2d different from the second direction 2b.

  The first photomask 20a further includes a first additional pattern 18a that is disposed in the fourth region 8d and has a width W2 that is narrower than the width W1 of the bump pattern 16. The fourth region 8d has a dimension that is longer than at least one of the second pitch 4b and the fourth pitch 4d in at least one direction (the fourth direction 2d in the example of FIG. 6A) (an example of the example of FIG. 6A). W8).

  For example, as shown in FIG. 6B, the first additional pattern 18a is arranged at the fifth pitch in the fifth direction 2e. The first additional pattern 18a is further arranged at a sixth pitch in a sixth direction 2f different from the fifth direction 2e. For example, the fifth direction 2e is a direction orthogonal to the sixth direction 2f.

  The fifth pitch of the first additional pattern 18a in the fifth direction 2e is preferably narrower than the second pitch 4b and the fourth pitch 4d of the bump pattern 16. Similarly, the pitch of the first additional pattern 18a in the sixth direction 2f is preferably narrower than the second pitch 4b and the fourth pitch 4d of the bump pattern 16. However, the first additional pattern 18a may be randomly arranged.

  The pitches 4b and 4d of the bump pattern 16 are, for example, 100 μm or more and 400 μm or less (or 150 μm or more and 300 μm or less). The width W1 of the bump pattern 16 is, for example, 50 μm or more and 300 μm or less (or 100 μm or more and 200 μm or less).

  One side of the fourth region 8d is, for example, 200 μm or more (or 250 μm or more).

  The fifth pitch and the sixth pitch of the first additional pattern 18a are, for example, 10 μm or more and 40 μm or less (or 15 μm or more and 30 μm or less). The width W2 of the first additional pattern 18a is, for example, 5 μm or more and 20 μm or less (or 7 μm or more and 15 μm or less).

  An example of the pitch of the bump pattern 16 is 200 μm, for example. An example of the width W1 of the bump pattern 16 is 150 μm, for example.

  An example of the fourth region 8d is a rectangular region having a short side of 275 μm and a long side of 350 μm, for example. An example of the fifth pitch and the sixth pitch of the first additional pattern 18a is, for example, 20 μm. An example of the width W2 of the first additional pattern 18a is, for example, 10 μm.

(3) Residue suppression The mechanism by which the residue of the negative photoresist film is suppressed according to the first embodiment will be described.

(3-1) Formation of Resist Pattern First, the mechanism of pattern formation and peeling of a negative photoresist will be described.

  When the negative photoresist film is irradiated with exposure light, molecules contained in the negative photoresist film are cross-linked and the negative photoresist film becomes insoluble in the developer. Therefore, when the negative photoresist film irradiated with the exposure light is immersed in the developer, the portion irradiated with the exposure light is not removed, and the portion not irradiated with the exposure light is removed. As a result, a resist pattern is formed.

  The negative photoresist film is cured simultaneously with insolubilization by exposure to exposure light. Both insolubilization and curing of the negative photoresist film are caused by cross-linking of molecules contained in the negative photoresist film.

(3-2) Stripping of resist pattern When an insolubilized resist pattern is immersed in a stripping solution, the resist pattern swells and loses adhesion to the substrate (for example, the semiconductor substrate 12). As a result, the resist pattern is peeled from the substrate while being divided into a plurality of peeling pieces.

(3-3) Mechanism of Residue Generation FIG. 9 is a diagram for explaining a mechanism of generating a residue of a negative photoresist film.

  Now, as shown in FIG. 9A, consider the case where the negative photoresist film 14 is irradiated with the exposure light 22 through a photomask having only the bump pattern 16.

  The intensity of the exposure light 22 in the first portion 62a sandwiched between the bump patterns 16 in the negative photoresist film 14 is such that the exposure light 22 in the second portion 62b in the negative photoresist film 14 that is not sandwiched between the bump patterns 16. The strength is almost the same. Accordingly, the first portion 62a sandwiched between the projecting electrodes 26 (see FIG. 9B) and the second portion 62b not sandwiched between the projecting electrodes 26 are insolubilized to the same extent to form a resist pattern. Here, the second portion 62b not sandwiched between the bump patterns 16 is a region located below the fourth region 8d of the first photomask 20a in the negative photoresist film 14.

  After the bump electrode 26 is formed, as shown in FIG. 9B, when the insolubilized negative photoresist film 14 is immersed in the stripping solution 64, the stripping solution 64 is applied to the first portion 62a sandwiched between the bump electrodes 26. Invade from the surface and side surface of the negative photoresist film 14. As a result, the negative photoresist film 14 is sufficiently swollen and easily peeled off from the semiconductor substrate 12. Therefore, a residue is hardly generated between the protruding electrodes 26. Note that an arrow 66 in FIG. 9B indicates the stripping solution 64 that has entered the negative photoresist film 14.

  On the other hand, the stripping solution 64 penetrates only from the surface of the negative photoresist film 14 into the second portion 62 b not sandwiched between the protruding electrodes 26. Therefore, the negative photoresist film 14 cannot swell sufficiently. As a result, as shown in FIG. 9C, a residue 72 fixed to the semiconductor substrate 12 is generated in a region not sandwiched between the protruding electrodes 26. When the residue 72 is generated, the yield of the semiconductor device is reduced.

(3-4) Residue Reduction According to the first embodiment, the first additional pattern 18a is arranged in the blank area (the fourth area 8d in FIG. 6) of the bump pattern 16 in the first photomask 20a. The first additional pattern 18 a reduces the exposure light 22 that passes through the blank area 8 d of the bump pattern 16. Due to the decrease in the exposure light 22, the insolubilization and curing of the negative photoresist film 14 are suppressed below the blank area 8 d of the bump pattern 16. As a result, the negative photoresist film 14 tends to swell. Therefore, the negative photoresist film 14 is easily peeled off from the semiconductor substrate 12, and the generation of residues is suppressed.

  The insolubilization and curing of the negative photoresist film 14 are not uniformly suppressed. For example, a shadow 54b (see FIG. 8B) is formed immediately below the first additional pattern 18a. Accordingly, insolubilization and hardening are suppressed immediately below the first additional pattern 18a from around the first additional pattern 18a.

  However, as a whole of the lower side of the fourth region 8d (see FIG. 6A) where the first additional pattern 18a is arranged, the insolubilization and curing of the negative photoresist film 14 are suppressed. As a result, the generation of a residue of the negative photoresist film 14 (hereinafter referred to as a resist residue) is suppressed.

-Number of first additional patterns per unit area-
The narrower the interval between the first additional patterns 18a, the narrower the interval between the shadows 54b (see FIG. 8B) of the first additional pattern 18a. Then, the area | region where the insolubilization and hardening were suppressed by the shadow 54b approaches. As a result, the insolubilized and hardened region is divided without entering the shadow 54b, and the negative photoresist film 14 is likely to swell. Therefore, the interval between the first additional patterns 18a is preferably as narrow as possible.

  The first additional pattern 18a may be randomly arranged. Regardless of whether the arrangement of the first additional patterns 18a is periodic or random, it is preferable that the number of the first additional patterns 18a per unit area is larger.

  Specifically, the number of first additional patterns 18a per unit area in the fourth region 8d (see FIG. 6A) is the number of bump patterns 16 per unit area in the third region 8c (= 1 / { (Second pitch 4b) × (fourth pitch 4d)}) is preferable.

  According to the first embodiment, since the first additional pattern 18a is arranged in the blank area 8d of the bump pattern 16, the exposure light transmitted through the blank area 8d is reduced. Therefore, it is possible to suppress the generation of resist residues that occur in the empty area 8b (see FIG. 5) where the protruding electrodes 26 are not formed. As a result, the yield of the semiconductor device is improved.

  Further, according to the first embodiment, the opening corresponding to the first additional pattern 18a is not formed in the negative photoresist film 14 by reducing the width of the first additional pattern 18a below the resolution of the negative photoresist film 14. Furthermore, the generation of resist residues can be suppressed.

  Even if the first additional pattern 18a is not provided, a resist residue may not be generated depending on the exposure conditions. Even in such a case, according to the first embodiment, since the negative photoresist film 14 is easily peeled off, the time for immersing the negative photoresist film 14 in the stripper (hereinafter referred to as the stripping time) is shortened. Thus, throughput can be improved.

(Embodiment 2)
The second embodiment is a method for manufacturing a semiconductor device in which exposure light is irradiated to a negative photoresist film through a second photomask different from the first photomask 20a. Except for the second photomask, the manufacturing method of the second embodiment is substantially the same as the manufacturing method of the first embodiment. Therefore, the description of the same parts as those in Embodiment 1 is omitted or simplified.

  FIG. 10 is a diagram illustrating the second photomask 20b. FIG. 10A is an example of a plan view of the second photomask 20b. FIG. 10B is an enlarged view of the region B shown in FIG. FIG. 11 is a partially enlarged view of FIG.

  As shown in FIG. 10A, the second photomask 20b is similar to the first photomask 20a described with reference to FIG. In the fourth region 8d of the second photomask 20b, a second additional pattern 18b (see FIG. 10B) is arranged instead of the first additional pattern 18a (see FIG. 6B). Except for the second additional pattern 18b, the second photomask 20b has substantially the same structure as the first photomask 20a.

  As shown in FIGS. 10B and 11, the second additional pattern 18b has a first portion 28a extending in the fifth direction 2e. The second additional pattern 18b further includes a second portion 28b extending in a sixth direction 2f different from the fifth direction 2e and intersecting the first portion 28a. The second additional pattern 18b is, for example, a light shielding film pattern. For example, the fifth direction 2e is a direction orthogonal to the sixth direction 2f.

  The first portion 28a is a pattern having a width W3 (see FIG. 10B) narrower than the width W1 of the bump pattern 16 (see FIG. 10A). The second portion 28b is a pattern having a width W4 (see FIG. 10B) narrower than the width W1 of the bump pattern 16 (see FIG. 10A). The first portion 28 a and the second portion 28 b have a light shielding film and are patterns that shield the exposure light 22.

  Under the fourth region 8d, the exposure light 22 irradiated to the negative photoresist film 14 is reduced by the second additional pattern 18b. Therefore, the generation of resist residues is suppressed.

  The second additional pattern 18 b is preferably a dummy pattern that does not form an opening in the negative photoresist film 14. Accordingly, the width W3 of the first portion 28a and the width W4 of the second portion 28b are preferably less than or equal to the resolution of the negative photoresist film 14.

  For example, as shown in FIG. 10B, the first portion 28a is periodically arranged in the sixth direction 2f. The pitch of the first portions 28a is preferably narrower than the second pitch 4b and the fourth pitch 4d of the bump pattern 16.

  Similarly, the second portion 28b is periodically arranged in the fifth direction 2e, for example. The pitch of the second portion 28b is preferably narrower than the second pitch 4b and the fourth pitch 4d of the bump pattern 16. The first portion 28a and the second portion 28b may be randomly arranged.

  Regardless of whether the arrangement is periodic or random, the number of the first portions 28a per unit length along the sixth direction 2f is the unit length along one direction (the second direction 2b or the fourth direction 2d). It is preferable that the number is larger than the number of the bump patterns 16 per unit. The number of bump patterns 16 per unit length along the second direction 2b is 1 / (second pitch 4b). The number of bump patterns 16 per unit length along the fourth direction 2d is 1 / (fourth pitch 4d).

  Of the negative photoresist film 14 on the lower side of the fourth region 8d, the region that is irradiated with the exposure light 22 and insolubilized and hardened is subdivided by the shadow of the first portion 28a. As a result, the insolubilized and hardened region easily swells, and the negative photoresist film 14 becomes more easily peeled off. Therefore, the negative photoresist film 14 can be more easily removed by increasing the number of the first portions 28a per unit length.

  Similarly, the area of the negative photoresist film 14 below the fourth area 8d that is irradiated with the exposure light 22 and insolubilized and hardened is subdivided by the shadow of the second portion 28b. As a result, the insolubilized and hardened region easily swells, and the negative photoresist film 14 becomes more easily peeled off. Therefore, the negative photoresist film 14 can be more easily removed by increasing the number of the second portions 28b per unit length.

  The pitch of the first part 28a in the sixth direction 2f and the pitch of the second part 28b in the fifth direction 2e are, for example, 10 μm or more and 40 μm (or 15 μm or more and 30 μm or less). The width W3 of the first portion 28a and the width W4 of the second portion 28b are, for example, 5 μm to 20 μm (or 7 μm to 15 μm). The same applies to the pitch and width of the second portion 28b.

  An example of the pitch in the sixth direction 2f of the first portion 28a and the pitch in the fifth direction 2e of the second portion 28b is, for example, 20 μm. An example of the width W3 of the first portion 28a and the width W4 of the second portion 28b is, for example, 10 μm.

  According to the second embodiment, since the second additional pattern 18b whose width of each part is narrower than the bump pattern 16 is arranged in the blank area 8d of the bump pattern 16, the exposure light transmitted through the blank area 8d is reduced. . Therefore, it is possible to suppress the generation of resist residue that occurs in the empty area 8b where the protruding electrode 26 is not formed. As a result, the yield of the semiconductor device is improved.

  Further, according to the second embodiment, the width of each portion of the second additional pattern 18b is set to be equal to or lower than the resolution of the negative photoresist film 14 so that the opening corresponding to the second additional pattern 18b is formed in the negative photoresist film 14. Generation | occurrence | production of a resist residue can be suppressed without forming.

  Even if the second additional pattern 18b is not provided, a resist residue may not be generated depending on the exposure conditions. Even in such a case, as in the first embodiment, the negative photoresist film 14 is easily peeled off, so that the peeling time can be shortened and the throughput can be improved.

(Embodiment 3)
The third embodiment is a method for manufacturing a semiconductor device in which exposure light is irradiated to a negative photoresist film through a photomask different from the first photomask 20a of the first embodiment. Except for this photomask, the manufacturing method of the third embodiment is substantially the same as the manufacturing method of the first embodiment. Therefore, the description of the same parts as those in Embodiment 1 is omitted or simplified.

  FIG. 12 is a plan view for explaining an example of the photomask 120a of the third embodiment. The photomask 120a of the third embodiment is a photomask having a third additional pattern in the outer edge region 50 in addition to the first photomask 20a of the first embodiment. Except for the third additional pattern, the photomask 120a of the third embodiment has substantially the same structure as the first photomask 20a of the first embodiment.

  FIG. 13 is an enlarged view of region C shown in FIG. The third additional pattern 18c is a pattern having a width W5 (see FIG. 13) narrower than the width W1 of the bump pattern 16 (see FIG. 12). The third additional pattern 18c is, for example, the same pattern as the first additional pattern 18a described with reference to FIG.

  The third additional pattern 18 c is preferably a dummy pattern that does not form an opening in the negative photoresist film 14. Accordingly, the width W5 of the third additional pattern 18c is preferably less than or equal to the resolution of the negative photoresist film 14.

  The step of irradiating the negative photoresist film 14 with the exposure light 22 (see FIG. 3C) is performed a plurality of times while moving the irradiation position of the exposure light 22 on one semiconductor substrate 12. At this time, the irradiation position of the exposure light 22 is moved so that the position corresponding to the outer edge region 50 overlaps the semiconductor substrate 12. Therefore, the exposure light 22 is irradiated a plurality of times to the region corresponding to the outer edge region 50 in the negative photoresist film 14. As a result, in the region corresponding to the outer edge region 50, the insolubilization and curing of the negative photoresist film 14 are promoted, and a residue is easily generated. A region corresponding to the outer edge region 50 substantially corresponds to the dicing line 11 (see FIG. 5). If a residue of the negative photoresist film 14 is generated in the dicing line 11, dicing is hindered and the yield of the semiconductor device is reduced.

  As described above, the third additional pattern 18c is disposed in the outer edge region 50 of the photomask 120a. Therefore, according to the third embodiment, it is possible to suppress the generation of resist residues in the dicing line 11 (see “(3) Residue suppression” in the first embodiment). As a result, the yield of the semiconductor device is improved.

  According to the third embodiment, further, the width of the third additional pattern 18c is set to be equal to or lower than the resolution of the negative photoresist film 14, so that the opening corresponding to the third additional pattern 18c is not formed in the negative photoresist film 14. Furthermore, the generation of resist residues can be suppressed.

  Even if the third additional pattern 18c is not provided, a resist residue may not be generated in the dicing line 11 depending on the exposure conditions. Even in such a case, according to the third embodiment, the negative photoresist film 14 is easily peeled off, so that the peeling time can be shortened and the throughput can be improved.

-Modification-
Additional patterns other than the third additional pattern 18c may be arranged in the outer edge region 50. FIG. 14 is a diagram illustrating an example of an additional pattern arranged in the outer edge region 50 instead of the third additional pattern 18c.

  The additional pattern in FIG. 14 (hereinafter referred to as a fourth additional pattern 18d) has a third portion 28c extending in the seventh direction 2g. The fourth additional pattern 18d further includes a fourth portion 28d extending in the eighth direction 2h different from the seventh direction 2g and intersecting the third portion 28c. The fourth additional pattern 18d is, for example, a light shielding film pattern. The seventh direction 2g is, for example, a direction orthogonal to the eighth direction 2h.

  The third portion 28c is a pattern having a width W6 that is narrower than the width W1 of the bump pattern 16 (see FIG. 12). The fourth portion 28d is a pattern having a width W7 that is narrower than the width W1 of the bump pattern 16 (see FIG. 12).

  The fourth additional pattern 18 d is preferably a dummy pattern that does not form an opening in the negative photoresist film 14. Accordingly, the width W6 of the third portion 28c and the width W7 of the fourth portion 28d are preferably less than or equal to the resolution of the negative photoresist film 14.

  For example, the fourth additional pattern 18d is the same pattern as the second additional pattern 18b described with reference to FIG.

  According to the modification, the generation of residues in the dicing line 11 can be suppressed as in the example described with reference to FIGS. Therefore, the yield of the semiconductor device is improved.

  According to the modification, the opening corresponding to the fourth additional pattern 18d is formed in the negative photoresist film 14 by reducing the width of each portion of the fourth additional pattern 18d below the resolution of the negative photoresist film 14. Therefore, the generation of resist residues can be suppressed.

  Alternatively, as in the example described with reference to FIGS. 12 and 13, the stripping time of the negative photoresist film 14 can be shortened to improve the throughput.

(Embodiment 4)
The fourth embodiment is a method of manufacturing a semiconductor device that irradiates a negative photoresist film with exposure light through a photomask different from the second photomask 20b of the second embodiment. Except for this photomask, the manufacturing method of the fourth embodiment is substantially the same as the manufacturing method of the second embodiment. Therefore, the description of the same parts as those in Embodiment 2 is omitted or simplified.

  FIG. 15 is a plan view for explaining an example of the photomask 120b according to the fourth embodiment. The photomask 120b of the fourth embodiment is a photomask having an additional pattern in the outer edge region 50 in addition to the second photomask 20b of the second embodiment. Except for this additional pattern, the photomask 120b of the fourth embodiment has substantially the same structure as the second photomask 20b of the second embodiment.

  The additional pattern of the fourth embodiment is, for example, the same pattern as the third additional pattern 18c (see FIG. 13) described in the third embodiment. The additional pattern of the fourth embodiment may be the same pattern as the fourth additional pattern 18d (see FIG. 14) described in the third embodiment.

  According to the fourth embodiment, as in the third embodiment, the generation of resist residues in the dicing line 11 can be suppressed. As a result, the yield of the semiconductor device is improved.

  Further, according to the fourth embodiment, as in the third embodiment, the generation of resist residue is suppressed without forming the opening corresponding to the third additional pattern 18c or the fourth additional pattern 18d in the negative photoresist film 14. It becomes possible to do.

  Further, as in the third embodiment, since the negative photoresist film 14 is easily peeled off, the peeling time of the negative photoresist film 14 can be shortened and the throughput can be improved.

  As mentioned above, although embodiment of this invention was described, Embodiment 1-4 is illustration and is not restrictive.

  For example, in Embodiments 1 to 4, solder bumps are formed in the openings 24 of the negative photoresist film 14. However, an electrode other than the solder bump may be formed in the opening 24 of the negative photoresist film 14. For example, a conductive column electrode may be formed in the opening 24 of the negative photoresist film 14 by plating.

  In the above example, the first additional pattern 18a is a dot pattern. However, the first additional pattern 18a may not be a dot pattern. For example, the first additional pattern 18a may be a plurality of strip-shaped patterns extending in one direction. The same applies to the third additional pattern 18c.

  In the above example, the second portion 28b of the second additional pattern 18b is a region that intersects the first portion 28a. However, the second portion 28b may not intersect the first portion 28a. For example, the second part 28b may be a part in contact with one end of the first part 28a. The same applies to the fourth additional pattern 18d.

  In the above example, the fourth region 8d is rectangular. However, the fourth region 8d may not be rectangular. For example, the fourth region 8d may be L-shaped.

2a ... 1st direction 2b ... 3rd direction 2c ... 3rd direction 2d ... 4th direction 4a ... 1st pitch 4b ... 2nd pitch 4c ... 3rd pitch 4d ... 4th pitch 6 ... conductive pads 8a ... first region 8b ... second region 8c ... third region 8d ... fourth region 10 ... chip region 12 ... Semiconductor substrate 14 ... Negative photoresist film 16 ... Bump pattern 18a ... First additional pattern 18b ... Second additional pattern 18c ... Third additional pattern 18d ... Fourth additional pattern 20a ... 1st photomask 20b ... 2nd photomask 22 ... Exposure light 24 ... Opening 26 ... Projection electrode 28a ... 1st part 28b ... 2nd part 28c ... -3rd part 28d ... 4th part 48 ... pattern area 0 ... the outer edge area

Claims (7)

A negative photoresist film is formed on a semiconductor substrate having a first region having conductive pads arranged at a first pitch and a second region having a dimension longer than the first pitch in at least one direction. Process,
A plurality of bump patterns disposed in a third region corresponding to the first region and corresponding to the conductive pad, and a second bump pattern disposed in a fourth region corresponding to the second region and having a width narrower than a width of the bump pattern. Irradiating the negative photoresist film with exposure light through a photomask having one additional pattern;
After the step of irradiating the exposure light, developing the negative photoresist film to form an opening corresponding to the bump pattern in the negative photoresist film;
Forming a conductive electrode in the opening;
Removing the negative photoresist film after forming the electrode. A method for manufacturing a semiconductor device. 2. The semiconductor according to claim 1, wherein the number of the first additional patterns per unit area in the fourth region of the photomask is greater than the number of the bump patterns per unit area in the third region. Device manufacturing method. A negative photoresist film is formed on a semiconductor substrate having a first region having conductive pads arranged at a first pitch and a second region having a dimension longer than the first pitch in at least one direction. Process,
A plurality of bump patterns corresponding to the conductive pads disposed in a third region corresponding to the first region, and extending in one direction while being disposed in a fourth region corresponding to the second region. Irradiating the negative photoresist film with exposure light through a photomask having a second additional pattern including a first portion having a width narrower than the width;
After the step of irradiating the exposure light, developing the negative photoresist film to form an opening corresponding to the bump pattern in the negative photoresist film;
Forming a conductive electrode in the opening;
Removing the negative photoresist film after forming the electrode. A method for manufacturing a semiconductor device. The number of the first portions per unit length along a direction orthogonal to the direction in which the first portion extends is greater than the number per unit length along one direction of the bump pattern. A method for manufacturing a semiconductor device according to claim 3. The photomask further includes a third addition having a width narrower than a width of the bump pattern in an outer edge region extending along an outer edge of the pattern region corresponding to the chip region having the first region and the second region. The method for manufacturing a semiconductor device according to claim 1, further comprising a pattern. A plurality of bump patterns arranged at a second pitch in the third region;
And a first additional pattern disposed in a fourth region having a dimension longer than the second pitch in at least one direction and having a width narrower than a width of the bump pattern. A plurality of bump patterns arranged at a second pitch in the third region;
A second additional pattern including a first portion disposed in a fourth region having a dimension longer than the second pitch in at least one direction and extending in one direction and having a width narrower than a width of the bump pattern. mask.

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