JP4547187B2 - Manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device manufacturing technique, and more particularly to a technique effective when applied to the manufacture of a semiconductor device for forming bump electrodes.

  In JP 2003-309139 A (Patent Document 1), after forming a bump electrode on a semiconductor substrate, the semiconductor substrate on which the bump electrode is formed by a cleaning process is cleaned, and then the bump electrode formed on the semiconductor substrate is defective. A technique for performing an appearance inspection for the presence or absence of the above has been disclosed.

Japanese Unexamined Patent Publication No. 2000-031185 (Patent Document 2) discloses the following technique. That is, after bump electrodes are formed on the semiconductor substrate, a flux or a protective film is formed on the bump electrodes. Then, a back-grinding tape is attached with the bump electrode with a flux or a protective film, and the surface opposite to the bump electrode formation surface (the back surface of the semiconductor substrate) is ground. Subsequently, the backgrinding tape is peeled off, and then washed to remove the flux. Thereafter, a technique for performing an inspection process is disclosed.
JP 2003-309139 A (page 4, FIG. 1) JP 2000-031185 (page 3, FIG. 1)

  In recent years, an LCD (Liquid Crystal Display) is used for a display unit of a mobile phone or the like. In order to drive the LCD, a semiconductor device for driving the LCD called an LCD driver is required. The LCD driver is directly mounted on the LCD. Accordingly, LCD driver manufacturers provide LCD drivers to customers in the form of semiconductor chips without resin sealing.

  This LCD driver is manufactured as follows, for example. That is, after a plurality of MISFETs (Metal Insulator Semiconductor Field Effect Transistors) are formed on a semiconductor substrate, wirings for connecting the plurality of MISFETs are formed in multiple layers. Then, bump electrodes are formed on the uppermost layer wiring. Subsequently, after an electrical characteristic inspection (probe inspection) of the LCD driver is performed through the formed bump electrode, an adhesive tape for back grinding is attached on the bump electrode to protect the bump electrode. Next, the back surface of the semiconductor substrate (the surface opposite to the bump electrode formation surface) is ground to make the semiconductor substrate have a predetermined thickness. And the adhesive tape affixed on the bump electrode is peeled off. Subsequently, after the semiconductor substrate is cut into individual chips by dicing, the chips are stored in a tray and shipped.

  The LCD driver completed in this way is shipped, but some of the LCD drivers may have some bump electrodes dropped off. For this reason, an automatic visual inspection device (AVI: Auto Visual Inspection) is introduced during the manufacturing process of the LCD driver to detect the drop of the bump electrode and treat it as a defective product before shipping the LCD driver. ing. The appearance inspection by the automatic appearance inspection apparatus is performed after the bump electrode is formed and before the probe inspection is performed.

  However, due to the introduction of the inspection process by the automatic visual inspection apparatus, the drop-out defect of the bump electrode has been reduced, but not zero. Therefore, as a result of investigating that defective products with bump electrodes dropped out despite being inspected by automatic visual inspection equipment, in the process after inspection by automatic visual inspection equipment, It was found that dropout occurred. That is, after the inspection process by the automatic appearance inspection apparatus, there is a process of grinding the back surface of the semiconductor substrate through probe inspection. In this back surface grinding process, in order to protect the bump electrode formed on the surface of the semiconductor substrate, an adhesive tape is applied on the bump electrode, and then the back surface of the semiconductor substrate is ground. Then, when the back surface grinding of the semiconductor substrate is completed, the adhesive tape stuck on the bump electrode is peeled off. When the adhesive tape was peeled off, the weakly bonded bump electrode was dropped from the semiconductor substrate.

  An object of the present invention is to provide a semiconductor device manufacturing method capable of reducing the shipment of defective products from which bump electrodes have dropped to customers.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  A method of manufacturing a semiconductor device according to the present invention includes: (a) a step of forming a plurality of bump electrodes on a semiconductor substrate; and (b) a step of removing a defective bump electrode among the plurality of bump electrodes after the step (a). A step of accelerating, and a step of (c) inspecting the presence or absence of the plurality of bump electrodes after the step (b).

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  Shipment of defective products with bump electrodes dropped to customers can be reduced. That is, the reliability of products shipped to customers can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
FIG. 1 is a flowchart showing the flow of the manufacturing process of the semiconductor device according to the first embodiment. This flowchart is a diagram for explaining the formation of the bump electrode and the subsequent steps performed after forming the MISFET and the multilayer wiring on the semiconductor substrate. That is, FIG. 1 illustrates a process after forming a surface protective film (passivation film) on a semiconductor substrate, removing the surface protective film formed on the uppermost layer wiring, and opening the upper part of the uppermost layer wiring. FIG.

2 to 15 are cross-sectional views illustrating the manufacturing steps of the semiconductor device according to the first embodiment. First, a process of forming MISFETs Q ₁ and Q ₂ and wiring on the semiconductor substrate 1 will be briefly described with reference to FIG.

  As shown in FIG. 2, for example, a semiconductor substrate 1 having a specific resistance of about 1 to 10 Ωcm is prepared. The semiconductor substrate 1 is made of, for example, p-type single crystal silicon, and an element isolation region 2 is formed on the main surface thereof. The element isolation region 2 is made of silicon oxide and is formed by, for example, an STI (Shallow Trench Isolation) method or a LOCOS (Local Oxidization Of Silicon).

Next, the active regions separated by isolation regions 2 formed on the semiconductor substrate 1, i.e., to form a p-type well 3 in the region for forming the MISFET Q ₁ of n-channel type. The p-type well 3 is formed by introducing boron (B) or boron fluoride (BF ₂ ) by, for example, ion implantation. Similarly, an n-type well 4 is formed in a region where a p-channel type MISFET Q ₂ is to be formed. The n-type well 4 is formed by introducing phosphorus (P) or arsenic (As) by, for example, ion implantation.

  Subsequently, a gate insulating film 5 is formed on the semiconductor substrate 1. The gate insulating film 5 is made of, for example, a thin silicon oxide film, and can be formed using, for example, a thermal oxidation method.

  Then, gate electrodes 7 a and 7 b are formed on the gate insulating film 5. The gate electrodes 7a and 7b are formed as follows. First, after a polysilicon film 6 is formed on the gate insulating film 5 of the semiconductor substrate 1, the polysilicon film 6 is patterned by using a photolithography technique and an etching technique, whereby a gate electrode 7a made of the polysilicon film 6 is formed. , 7b.

  Next, lightly doped n-type impurity diffusion regions 8 and 9 which are semiconductor regions are formed in regions on both sides of the gate electrode 7a. The low-concentration n-type impurity diffusion regions 8 and 9 are formed by introducing an n-type impurity such as phosphorus into the p-type well 3 using an ion implantation method, for example. Similarly, low concentration p-type impurity diffusion regions 10 and 11 which are semiconductor regions are formed in regions on both sides of the gate electrode 7b. The low-concentration p-type impurity diffusion regions 10 and 11 are formed by introducing a p-type impurity such as boron or boron fluoride into the n-type well 4 using an ion implantation method, for example.

  Subsequently, sidewalls 12 are formed on the side walls of the gate electrodes 7a and 7b. The sidewall 12 can be formed by depositing a silicon oxide film on the semiconductor substrate 1 by using, for example, a CVD method and anisotropically etching the deposited silicon oxide film.

  After the sidewall 12 is formed, high-concentration n-type impurity diffusion regions 13 and 14 are formed in regions on both sides of the gate electrode 7a. The high-concentration n-type impurity diffusion regions 13 and 14 can be formed by introducing an n-type impurity such as phosphorus using an ion implantation method, for example. The high concentration n-type impurity diffusion regions 13 and 14 have a higher impurity concentration than the low concentration n-type impurity diffusion regions 8 and 9 described above. Similarly, high-concentration p-type impurity diffusion regions 15 and 16 are formed in regions on both sides of the gate electrode 7b. The high-concentration p-type impurity diffusion regions 15 and 16 can be formed by introducing a p-type impurity such as boron or boron fluoride using an ion implantation method, for example. In the high-concentration p-type impurity diffusion regions 15 and 16, p-type impurities are introduced at a higher concentration than in the low-concentration p-type impurity diffusion regions 10 and 11.

  Next, after exposing the surfaces of the high-concentration n-type impurity diffusion regions 13 and 14 and the high-concentration p-type impurity diffusion regions 15 and 16, a cobalt (Co) film is formed on the semiconductor substrate 1 by using, for example, a CVD method. Deposit. Then, a cobalt silicide film 17 is formed by performing heat treatment. Thereby, gate electrodes 7a and 7b made of the polysilicon film 6 and the cobalt silicide film 17 can be formed. Further, the cobalt silicide film 17 can be formed in the high concentration n-type impurity diffusion regions 13 and 14 and the high concentration p-type impurity diffusion regions 15 and 16. Therefore, the resistance of the gate electrodes 7a and 7b can be reduced, and the sheet resistance of the high-concentration n-type impurity diffusion regions 13 and 14 and the high-concentration p-type impurity diffusion regions 15 and 16 can be reduced. Thereafter, the unreacted cobalt film is removed.

In this manner, the n-channel type MISFET Q ₁ and the p-channel type MISFET Q ₂ can be formed.

  Subsequently, the wiring process will be described. An insulating film 18 to be an interlayer insulating film is deposited on the semiconductor substrate 1 by using, for example, a CVD method. Thereafter, a contact hole 19 penetrating the insulating film 18 is formed by using a photolithography technique and an etching technique. At the bottom of contact hole 19, cobalt silicide film 17 formed in high concentration n-type impurity diffusion regions 13 and 14 and high concentration p-type impurity diffusion regions 15 and 16 is exposed.

  Next, a plug 21 in which the titanium / titanium nitride film 20a and the tungsten film 20b are embedded in the contact hole 19 is formed. The plug 21 can be formed as follows, for example. First, a titanium / titanium nitride film 20a is formed on the insulating film 18 including the inside of the contact hole 19 by using, for example, a sputtering method, and then a tungsten film 20b is embedded in the contact hole 19 by using, for example, a CVD method. To form. Then, the unnecessary titanium / titanium nitride film 20a and the tungsten film 20b formed on the insulating film 18 are removed by using a CMP method or an etch back method, thereby forming the plug 21.

  Subsequently, a titanium / titanium nitride film 22a, an aluminum film 22b, and a titanium / titanium nitride film 22c are sequentially formed on the insulating film 18 on which the plug 21 is formed. These films can be formed using, for example, a sputtering method. Then, the wiring 23 is formed by patterning the titanium / titanium nitride film 22a, the aluminum film 22b, and the titanium / titanium nitride film 22c by using a photolithography technique and an etching technique. By repeating this wiring process, a multilayer wiring can be formed.

Next, the process of forming the uppermost layer wiring among the multilayer wiring will be described. As shown in FIG. 3, an insulating film 30 is formed on the semiconductor substrate 1. The insulating film 30 is made of, for example, a silicon oxide film, and can be formed using, for example, a CVD method. Here, in FIG. 3 and subsequent figures, MISFETs Q ₁ and Q ₂ formed on the semiconductor substrate 1 and wirings formed below the uppermost layer wiring are not shown.

  Subsequently, after forming an aluminum film on the insulating film 30 by using, for example, a sputtering method, the aluminum film is patterned by using a photolithography technique and an etching technique to thereby form wirings 31a to 31d that are uppermost layer wirings. Form.

  Next, a surface protective film 32 is formed on the insulating film 30 and the wirings 31a to 31d. The surface protective film 32 can be formed by using, for example, a silicon nitride film on the insulating film 30 and the wirings 31a to 31d by using a plasma CVD method. Then, as shown in FIG. 4, an opening is formed in the surface protective film 32 by using a photolithography technique and an etching technique. That is, the surface protection film 32 formed on the wirings 31a to 31d is removed to expose the wirings 31a to 31d.

  Since the steps from the next step to the subsequent steps are also described in the flowchart of FIG. 1, they will be described with reference to FIG.

  As shown in FIG. 5, a UBM (Under Bump Metal) film (electrode base film) 33 is formed on the surface protection film 32 and the exposed wirings 31a to 31d (S101 in FIG. 1). The UBM film 33 is formed of, for example, a laminated film of a palladium film and a titanium film or a laminated film of a titanium tungsten film and a gold film, and can be formed by, for example, a sputtering method. When a laminated film of a palladium film and a titanium film is used as the UBM film 33, the adhesion of the UBM film 33 is improved, and the UBM film 33 is difficult to peel off from the base film.

  Here, although the UBM film 33 is formed on the wirings 31a to 31d, the wirings 31a to 31d are mainly formed of an aluminum film. Since the aluminum film is easily oxidized, it is considered that the aluminum oxide film is formed on the surfaces of the wirings 31a to 31d. If an aluminum oxide film is formed on the surfaces of the wiring 31a to the wiring 31d, the adhesion between the wiring 31a to the wiring 31d and the UBM film 33 is lowered. Therefore, usually, before the UBM film 33 is formed, a sputter etching method or the like is used. Is used to remove the aluminum oxide film.

  However, if abnormal discharge or the like occurs in the sputter etching method, the adhesiveness is lowered. For example, it is assumed that the adhesion between the wiring 31b and the UBM film 33 is reduced due to abnormal discharge.

  Next, after a resist film 34 is applied on the UBM film 33, the resist film 34 is patterned by exposing and developing the resist film 34 (S102 in FIG. 1). As shown in FIG. 6, the patterning is performed so as to open the upper portions of the wirings 31a to 31d. Here, in order to form a bump electrode by embedding a gold film in an opening of the resist film 34 in a process described later, the thickness of the resist film 34 is determined in accordance with the height of the bump electrode to be formed.

  Subsequently, as shown in FIG. 7, a gold film 35 is formed so as to fill the opening of the resist film 34. The gold film 35 can be formed, for example, by using an electroplating method using the UBM film 33 as an electrode (S103 in FIG. 1). Then, as shown in FIG. 8, the patterned resist film 34 is removed (S104 in FIG. 1). At this time, the UBM film 33 formed under the resist film 34 is exposed.

  Next, as shown in FIG. 9, by using the gold film 35 as a mask, the exposed UBM film 33 is removed by etching (S105 in FIG. 1), so that the bump electrode 36a to the bump electrode 36d are formed on the wiring 31a to the wiring 31d. Form. In this way, bump electrodes 36a to 36d made of the UBM film 33 and the gold film 35 are formed.

  Here, when the exposed UBM film 33 is etched, the UBM film 33 on which the gold film 35 is formed is not exposed because it is not exposed. However, even in the UBM film 33 having the gold film 35 formed on the upper part, the UBM film 33 may be etched by the penetration of the etchant from the side surfaces on both sides. The bump electrode 36c formed on the wiring 31c, for example, is an example of the bump electrode in which the UBM film 33 is soaked with the etching solution. In the bump electrode 36c, since the UBM film 33 is etched from the side surface, as shown in FIG. 9, the UBM film 33 remains only in a small region at the center of the bump electrode 36c. Therefore, the adhesive force between the wiring 31c and the bump electrode 36c is weaker than when the UBM film 33 is not etched.

  Further, in the bump electrode 36b, the adhesiveness between the wiring 31b and the UBM film 33 is lowered due to the abnormal discharge of the sputter etching method as described above. Therefore, the adhesive force between the wiring 31b and the bump electrode 36b is weaker than in the normal case.

  Next, heat treatment (annealing) is performed on the semiconductor substrate 1 so that the gold film 35 constituting the bump electrodes 36a to 36d is made into a stable crystal (S106 in FIG. 1).

Then, as shown in FIG. 10, a mixture of water (H ₂ O) and nitrogen gas (N ₂ ) is sprayed from the nozzle 37 onto the bump electrode formation surface of the semiconductor substrate 1 (S107 in FIG. 1). That is, by spraying water and nitrogen gas at the same time, mist-like water is vigorously sprayed onto the bump electrodes 36a to 36d. In this way, by spraying a mixture of water and nitrogen gas onto the bump electrodes 36a to 36d using the mist jet method, as shown in FIG. The bump electrode 36c can be removed at an accelerated rate. The mist jet method refers to a method in which a liquid and gas mixture are simultaneously jetted to make the liquid mist and jet the target. According to this mist jet method, only the bumps 36b and 36c having a weak adhesive force can be removed without affecting the normal bump electrodes 36a and 36d.

  According to the mist jet method using a mixture of water and nitrogen gas, since the adjustment range of the jetting intensity is wide, only the bump electrode 36b and the bump electrode 36c with weak adhesive force that may cause dropout are removed, and normal It becomes easy to adjust the jetting intensity so as to leave the bump electrode 36a and the bump electrode 36d.

  In the first embodiment, the mist jet method using a mixture of water and nitrogen gas has been described. However, the present invention is not limited to this, and a mixture of liquid and gas other than the mixture of water and nitrogen gas may be used. In addition to the mist jet method that uses a mixture of liquid and gas, by ejecting liquid, gas, or a solid with a small particle size, only bump electrodes with weak adhesive force that may cause dropout are removed. May be. In the method of applying a peeling force to the bump electrode by injecting a solid having a small particle size, the particle size of the solid is such that the peeling force is independently applied to each bump electrode. It is preferable to use a bump electrode having a diameter smaller than that of the bump electrodes or a distance between the bump electrodes.

  In the first embodiment, a mixture of water and nitrogen gas is sprayed onto the bump electrode mainly for the purpose of removing the bump electrode, which has a weak adhesive force and is likely to fail to drop off. However, the mixture of water and nitrogen gas is sprayed onto the bump electrode. By spraying on, the foreign matter on the bump electrode formation surface of the semiconductor substrate 1 can be removed. That is, there is an advantage that the bump electrode forming surface of the semiconductor substrate 1 can be cleaned at the same time.

  Next, FIG. 12 shows a state after removing the bump electrode 36b and the bump electrode 36c, which have a weak adhesive force and are liable to drop off. As shown in FIG. 12, only the bump electrode 36b whose adhesiveness is reduced due to abnormal discharge of the sputter etching method and the bump electrode 36c whose adhesiveness with the wiring 31c is reduced due to etching of the UBM film 33 are water. It can be seen that it is removed by spraying a mixture of nitrogen and nitrogen gas (mist jet method).

  Subsequently, an appearance inspection is performed for the presence or absence of the bump electrodes formed on the semiconductor substrate 1 (S108 in FIG. 1). This visual inspection is performed using an automatic visual inspection device (AVI: Auto Visual Inspection). Here, among the semiconductor devices formed in the chip region of the semiconductor substrate 1, those in which the bump electrode 36b and the bump electrode 36c are dropped are treated as defective products. As described above, by providing a step of accelerating removal of the bump electrode that is likely to be a drop-off defect before the inspection process (AVI inspection) by the automatic appearance inspection apparatus, the drop-off defect is likely to occur in the appearance inspection process. A semiconductor device having a bump electrode can be treated as a defective product. That is, when the defect of the bump electrode drop occurs after the inspection process by the automatic visual inspection apparatus, the defective product without the bump electrode is shipped as a product, and the quality of the product is deteriorated. However, in the first embodiment, a semiconductor device having a bump electrode that is likely to drop off is automatically appearance by providing a step of accelerating removal of the bump electrode that is easily dropped before the inspection step by the automatic appearance inspection apparatus. It can be processed as a defective product by the inspection device. Therefore, according to this Embodiment 1, the quality of the product shipped can be improved.

  Here, a prior art document (Japanese Patent Laid-Open No. 2003-309139) discloses a technique in which a bump electrode is formed, a cleaning process is performed, and then an appearance inspection process is performed. However, the purpose of removing the defective bump electrode in the cleaning process is not described. Perhaps this prior art cleaning step is thought to be intended to remove the flux after solder reflow and can be cleaned, for example, by immersing it in a still water bath or by immersing it in alcohol. In such a process, the object of the present invention is not achieved, in which a defective bump electrode that has a weak adhesive force and is likely to cause a drop-off defect is peeled off. In the first embodiment, gas / liquid, a mixture of gas and liquid, or a solid with a small particle diameter is ejected vigorously from the nozzle 37 to generate a desired peeling force on each bump electrode, thereby causing an adhesive force. One feature is that a defective bump electrode that is weak and easily causes a drop-off defect is removed at an accelerated rate, and then an inspection is performed by an automatic visual inspection apparatus.

  Next, a probe (probe) is brought into contact with the bump electrode formed on the semiconductor substrate 1 to inspect the electrical characteristics of the semiconductor device (S109 in FIG. 1). Then, the back surface of the semiconductor substrate 1 is ground (back grinding) (S110 in FIG. 1). The back surface grinding of the semiconductor substrate 1 is performed as follows. That is, as shown in FIG. 13, the adhesive sheet 38 is affixed to the bump electrode formation surface of the semiconductor substrate 1. This adhesive sheet 38 is provided to protect the bump electrodes. Subsequently, as shown in FIG. 14, the back surface of the semiconductor substrate 1 is ground by a polishing machine 39 with the bump electrode formation surface to which the adhesive sheet 38 is attached facing down. Then, when the grinding by the polishing machine 39 is completed, as shown in FIG. 15, the adhesive sheet 38 attached to the bump electrode formation surface is peeled off. At this time, in the conventional process, there is a problem that a bump electrode that is easily dropped due to a decrease in adhesiveness is stuck to the adhesive sheet 38 and dropped from the semiconductor substrate 1. That is, in the conventional process, there is no process for accelerating removal of the bump electrode having a weak adhesive force before the inspection process by the automatic visual inspection apparatus as in the first embodiment. Therefore, in the inspection by the automatic appearance inspection apparatus, it is determined that the bump electrode is present and is judged to be a non-defective product. However, in the subsequent back grinding process, the adhesive force is weak and the adhesive sheet 38 is peeled off from the semiconductor substrate 1 when it is peeled off. Will be removed. In such a case, a product without a bump electrode is shipped, and the quality of the product is deteriorated.

  On the other hand, in the first embodiment, the bump electrode having a weak adhesive force is acceleratedly removed before the inspection process by the automatic visual inspection apparatus. For this reason, the bump electrode that is not removed in this step is normal and has high adhesive strength. Therefore, it is possible to reduce the bump electrode from falling off due to the peeling of the adhesive sheet 38 in the subsequent back grinding process. As described above, according to the first embodiment, it is possible to prevent a semiconductor device that has been determined to be a non-defective product in the inspection process by the automatic visual inspection apparatus from falling out of the bump electrode and becoming a defective product in the subsequent process. .

  Next, the semiconductor substrate 1 is diced and cut into individual chips (S111 in FIG. 1). Here, a chip on which a semiconductor device which has been determined to be defective by the automatic appearance inspection apparatus is excluded as a defective product. Only good chips are stored in the tray (S112 in FIG. 1) and shipped (S113 in FIG. 1).

  Although it is possible to inspect the appearance of the chip after it has been cut into individual chips, the bump electrodes dropped off in the semiconductor device that was judged as a non-defective product in the inspection process by the automatic appearance inspection device. Therefore, it is possible to reduce the work load.

(Embodiment 2)
In the first embodiment, a mist jet method in which a mixture of water and nitrogen gas is sprayed onto the bump electrode is used as a means for accelerating removal of the bump electrode having a weak adhesive force. An example in which an adhesive sheet is used as means for accelerating removal of a weak bump electrode will be described.

  FIG. 16 is a flowchart showing the flow of the semiconductor device manufacturing method according to the second embodiment. FIG. 16 is almost the same as FIG. 1 showing the flow (flow chart) of the method for manufacturing the semiconductor device in the first embodiment, and therefore, different steps will be mainly described.

  In FIG. 16, steps S201 to S206 are the same as in the first embodiment, and through these steps, bump electrodes 36a to 36d are formed on the semiconductor substrate 1 as shown in FIG. it can. Then, the adhesive sheet 40 is affixed on the bump electrode formation surface of the semiconductor substrate 1 (S207 in FIG. 16). And as shown in FIG. 18, the adhesive sheet 40 affixed on the bump electrode formation surface of the semiconductor substrate 1 is peeled off (S208 of FIG. 16). At this time, the bump electrode 36b and the bump electrode 36c, which have a weak adhesive force and are liable to be dropped off, are peeled off from the semiconductor substrate 1 due to the adhesive force of the adhesive sheet 40 and attached to the adhesive sheet 40. On the other hand, the normal bump electrode 36a and the bump electrode 36d have a strong adhesive force and are not peeled off from the semiconductor substrate 1.

  In this way, only the bump electrode 36b and the bump electrode 36c, which have a weak adhesive force and are likely to drop off, can be removed at an accelerated rate. Note that the adhesiveness of the adhesive sheet 40 is such that when the adhesive sheet 40 is peeled off, the bump electrodes 36a and 36d that are normally bonded to the semiconductor substrate 1 are not peeled off, and the bump electrodes 36b and 36c having a weak bonding force are not. It is adjusted to peel off.

  Next, an appearance inspection (AVI inspection) is performed for the presence or absence of bump electrodes formed on the semiconductor substrate 1 (S209 in FIG. 16), and then a probe inspection (S210 in FIG. 16) and back grinding (back grinding) of the semiconductor substrate 1 are performed. ) (S211 in FIG. 16). Then, after the semiconductor substrate 1 is cut into individual chips by dicing (S212 in FIG. 16), only non-defective products are stored in the tray (S213 in FIG. 16) and shipped (S214 in FIG. 16).

  According to the second embodiment, a step of accelerating removal of the bump electrodes that are easily dropped off by the adhesive sheet is provided before the inspection step by the automatic visual inspection apparatus. For this reason, a semiconductor device having a bump electrode that is likely to drop off can be processed as a defective product by an automatic visual inspection apparatus. Therefore, according to this Embodiment 2, generation | occurrence | production of the product which becomes defect after the test | inspection by an automatic external appearance inspection apparatus can be reduced, and the quality of the product shipped can be improved.

  Here, the prior art document (Japanese Patent Laid-Open No. 2000-031185) discloses a technique in which the back grind tape is peeled off after the bump electrode is formed and the bump electrode is protected with a flux or a protective film. . However, in a state where the bump electrodes are protected with a flux or a protective film, it is not possible to apply a peeling force to each bump electrode, and it is not possible to selectively remove only a defective bump electrode having a weak adhesive force. In the second embodiment, a peeling force is applied to each bump electrode with an adhesive tape without using a protective film or the like to selectively remove a defective bump electrode having a weak adhesive force. One feature is that an inspection process by an automatic appearance inspection apparatus is performed later. That is, one of the features of the second embodiment is that a step of accelerating removal of the bump electrodes that easily fall off is provided by the adhesive sheet, and an inspection step using an automatic visual inspection apparatus is performed after this step.

(Embodiment 3)
In the first embodiment and the second embodiment, a step of accelerating removal of the bump electrodes that are likely to fall off is provided before the inspection step by the automatic visual inspection apparatus. However, in the third embodiment, in particular, the step of accelerating removal of the bump electrode that is likely to drop off is also used as another step, thereby avoiding an increase in steps in the manufacturing step and reducing the manufacturing cost. An example will be described.

  FIG. 19 is a flowchart showing the flow of the semiconductor device manufacturing method according to the third embodiment. FIG. 19 is almost the same as FIG. 1 showing the flow (flow chart) of the method for manufacturing the semiconductor device in the first embodiment, and therefore, different steps will be mainly described.

  In FIG. 19, steps S301 to S306 are the same as those in the first embodiment, and a plurality of bump electrodes can be formed on the semiconductor substrate through these steps. Subsequently, after performing the probe inspection (S307 in FIG. 19), the back grinding of the semiconductor substrate is performed (S308 in FIG. 19). In the back grinding process of the semiconductor substrate, first, a protective adhesive sheet is attached to the bump electrode forming surface of the semiconductor substrate. At this time, it is preferable to stick the adhesive sheet so that it directly adheres to the individual bump electrodes. Then, the back surface of the semiconductor substrate is ground, and when the grinding is completed, the adhesive sheet attached to the bump electrode forming surface is peeled off. At this time, among the bump electrodes formed on the semiconductor substrate, the bump electrode that has a weak adhesive force and is likely to drop off is peeled off from the semiconductor substrate and stuck to the adhesive sheet.

  Conventionally, this back grinding process has been performed after an inspection process by an automatic visual inspection apparatus. For this reason, even if the automatic appearance inspection apparatus determines that the product is a good product, the bump electrode having weak adhesive force and easily falling off is peeled off in the back grinding process, and a defective product without the bump electrode has been shipped.

  However, in the third embodiment, an inspection process (AVI inspection) by an automatic visual inspection apparatus is performed after the back grinding process (S309 in FIG. 19). Therefore, even if a bump electrode that easily falls off in the back grinding process is peeled off, it is determined that the automatic visual inspection apparatus is defective, so that it is possible to prevent a defective product without a bump electrode from being shipped to a customer. Thus, in this Embodiment 3, since it comprised so that the test process by an automatic external appearance inspection apparatus might be performed after the back surface grinding process in which peeling of a bump electrode arises, the process of acceleratingly removing the bump electrode which is easy to drop off is carried out. Without being provided, defects that occur after the inspection process by the automatic visual inspection apparatus can be reduced.

  Next, after the semiconductor substrate is cut into individual chips by dicing (S310 in FIG. 19), only non-defective products are stored in the tray (S311 in FIG. 19) and shipped (S312 in FIG. 19).

(Embodiment 4)
In the fourth embodiment, an example will be described in which defects that occur after an inspection process by an automatic visual inspection apparatus can be reduced without providing a process for accelerating removal of bump electrodes that are likely to fall off.

  FIG. 20 is a flowchart showing the flow of the semiconductor device manufacturing method according to the third embodiment. 20, S401 to S406 are the same as those in the first embodiment, and a plurality of bump electrodes can be formed on the semiconductor substrate through these steps. Subsequently, after performing the probe inspection (S407 in FIG. 20), the back grinding of the semiconductor substrate is performed (S408 in FIG. 20). Next, the semiconductor substrate is cut into individual chips by dicing (S409 in FIG. 20), and then stored in the tray (S410 in FIG. 20). Then, after performing the inspection process (AVI inspection) by the automatic appearance inspection apparatus (S411 in FIG. 20), only the non-defective products are shipped (S412 in FIG. 20).

  Thus, according to the fourth embodiment, the inspection process by the automatic appearance inspection apparatus is performed immediately before shipping. Therefore, defects that occur after the inspection process by the automatic appearance inspection apparatus can be reduced. That is, since the inspection process by the automatic appearance inspection apparatus is performed at the end of the manufacturing process of the semiconductor device, it occurs after the inspection process by the automatic appearance inspection apparatus without providing a process for accelerating removal of the bump electrodes that are likely to fall off. Defects can be reduced.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  In the first to fourth embodiments described above, the bump electrode forming process including gold as a main component has been described as an example. However, the present invention is not limited to this, and for example, a solder bump forming process used in WPP (Wafer Process Package) is also used. Can be applied.

  In the first to fourth embodiments, the method for inspecting the presence / absence of the bump electrode is exemplified by the inspection process (AVI inspection) by the automatic visual inspection apparatus. However, the present invention is not limited to this. The presence or absence of the bump electrode may be inspected by making a probe inspection in which an electrical property inspection of the semiconductor device is performed by bringing a (probe) into contact.

  The present invention can be widely used in the manufacturing industry for manufacturing semiconductor devices having bump electrodes.

4 is a flowchart showing a flow of a manufacturing process of the semiconductor device in the first embodiment of the present invention. 7 is a cross-sectional view showing a manufacturing step of the semiconductor device in the first embodiment. FIG. FIG. 3 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 2; FIG. 4 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 3; FIG. 5 is a cross-sectional view showing the manufacturing process of the semiconductor device, following FIG. 4; FIG. 6 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 5; FIG. 7 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 6; FIG. 8 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 7; FIG. 9 is a cross-sectional view showing the manufacturing process of the semiconductor device, following FIG. 8; FIG. 10 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 9; FIG. 11 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 10; FIG. 12 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 11; FIG. 13 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 12; FIG. 14 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 13; FIG. 15 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 14; 10 is a flowchart showing a flow of a manufacturing process of a semiconductor device in the second embodiment. 11 is a cross-sectional view showing a manufacturing step of the semiconductor device in the second embodiment. FIG. FIG. 18 is a cross-sectional view showing a manufacturing step of the semiconductor device following that of FIG. 17; 10 is a flowchart showing a flow of a manufacturing process of a semiconductor device in a third embodiment. 10 is a flowchart showing a flow of a manufacturing process of a semiconductor device in a fourth embodiment.

Explanation of symbols

1 semiconductor substrate 2 element isolation region 3 p-type well 4 n-type well 5 gate insulating film 6 polysilicon film 7a gate electrode 7b gate electrode 8 low-concentration n-type impurity diffusion region 9 low-concentration n-type impurity diffusion region 10 low-concentration p-type Impurity diffusion region 11 Low-concentration p-type impurity diffusion region 12 Side wall 13 High-concentration n-type impurity diffusion region 14 High-concentration n-type impurity diffusion region 15 High-concentration p-type impurity diffusion region 16 High-concentration p-type impurity diffusion region 17 Cobalt silicide film 18 Insulating film 19 Contact hole 20a Titanium / titanium nitride film 20b Tungsten film 21 Plug 22a Titanium / titanium nitride film 22b Aluminum film 22c Titanium / titanium nitride film 23 Wiring 30 Insulating film 31a Wiring 31b Wiring 31c Wiring 31d Wiring 32 Surface protective film 33 UBM membrane 34 cash register Preparative layer 35 gold film 36a bump electrode 36b bump electrodes 36c bump electrode 36d bump electrode 37 nozzle 38 adhesive sheet 39 polisher 40 adhesive sheet

Claims (13)

(A) preparing a semiconductor wafer having a plurality of wirings and a main surface on which an insulating film exposing each of the plurality of wirings is formed;
(B) forming a plurality of bump electrodes on the main surface of the semiconductor wafer;
(C) injecting a mixture of gas and liquid onto the plurality of bump electrodes;
(D) a step of inspecting the appearance of the main surface of the semiconductor wafer;
(E) dicing the semiconductor wafer to divide it into individual semiconductor chips;
(F) storing the semiconductor chip in a tray and shipping it;
A method for manufacturing a semiconductor device, comprising: Wherein the main surface of the semiconductor wafer, a plurality of field effect transistors have been formed, the plurality of wires, according to claim 1, characterized in that it is electrically connected with the plurality of field effect transistors the method of manufacturing a semiconductor device. Each of the plurality of bump electrodes is formed by subjecting each of the plurality of wirings to sputter etching, forming a conductive film on the main surface of the semiconductor wafer, applying a resist film on the conductive film, A part of the conductive film is exposed from the resist film by removing the resist film in a region overlapping with each other, and a gold film is formed on the conductive film so as to embed the region from which the resist film has been removed. formed, the resist film by removing the method of manufacturing a semiconductor device according to claim 1, characterized in that it is formed on the main surface of the semiconductor wafer. 4. The method of manufacturing a semiconductor device according to claim 3 , wherein the gold film is formed by an electrolytic plating method. 4. The semiconductor device according to claim 3 , wherein after forming the plurality of bump electrodes on the main surface of the semiconductor wafer, the conductive film exposed from each of the plurality of bump electrodes in a plan view is removed by etching. Manufacturing method. 4. The method of manufacturing a semiconductor device according to claim 3 , wherein the conductive film is formed of a laminated film of a palladium film and a titanium film or a laminated film of a titanium tungsten film and a gold film . 2. The method of manufacturing a semiconductor device according to claim 1 , wherein after the plurality of bump electrodes are formed on the main surface of the semiconductor wafer, a heat treatment is performed on the semiconductor wafer on which the plurality of bump electrodes are formed . The method for manufacturing a semiconductor device according to claim 1 , wherein after inspecting the appearance of the main surface of the semiconductor wafer, a probe is brought into contact with the plurality of bump electrodes to perform inspection . Wherein after checking the appearance of the main surface of the semiconductor wafer, a method of manufacturing a semiconductor device according to claim 1, wherein the grinding the main surface with the back surface of the opposite side of the semiconductor wafer. The method for manufacturing a semiconductor device according to claim 9, wherein the back surface of the semiconductor wafer is ground in a state where an adhesive sheet is attached to the main surface of the semiconductor wafer. 11. The method of manufacturing a semiconductor device according to claim 10, wherein the sheet is peeled from the main surface of the semiconductor wafer before the semiconductor wafer is diced and divided into individual semiconductor chips. 2. The semiconductor chip stored in the tray is a semiconductor chip in which it is confirmed that the plurality of bump electrodes are formed in the step of inspecting the appearance of the main surface of the semiconductor wafer. The manufacturing method of the semiconductor device of description. 2. The method of manufacturing a semiconductor device according to claim 1, wherein nitrogen gas is used as the gas and water is used as the liquid.

Images