JP2012238627A - Semiconductor device manufacturing method and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device manufacturing method and a semiconductor device, in which defects caused by a protrusion part on a surface of an electrode pad are difficult to occur.SOLUTION: A semiconductor device manufacturing method comprises: a first insulation film formation process of forming a first insulation film 4 that covers at least a part of an electrode pad 2 on a substrate 1 equipped with the electrode pad 2 having a protrusion part such as a probing mark 21 on a protrusion part on a surface; a removal process of performing processing capable of removing a part 22 protruded from a surface of the first insulation film 4; and a second insulation film formation process of forming a second insulation film 5 on the first insulation film 4 and the electrode pad 2 after the removal process.

Description

  The present invention relates to a method of manufacturing a semiconductor device having an electrode pad provided on a substrate and an insulating film covering the electrode pad, and a semiconductor device.

  In general, in a semiconductor device having a wafer level chip size package (WL-CSP) structure, an insulating film is formed on a semiconductor wafer provided with circuit elements and electrode pads, an opening is formed in the insulating film, and an electrode is formed through the opening. Form a rewiring pattern that is electrically connected to the pad, form a mold resin that covers the rewiring pattern, form an opening in the mold resin, and external connections such as solder bumps that are electrically connected to the rewiring layer It is manufactured by forming a terminal. In addition, after the wafer process and before the formation of the insulating film, the probing needle (probe pin) of the probing device is brought into contact with the electrode pad to inspect whether each chip (semiconductor device) of the semiconductor wafer is good or defective. Done.

  However, when the probing needle is brought into contact with the electrode pad, a part of the electrode pad is scraped, and a probing mark including a protruding portion on the surface of the electrode pad may be generated. The protruding part of the probing mark may protrude on the insulating film formed so as to cover the electrode pad. In this case, the protruding part on the insulating film breaks the rewiring pattern. was there.

  Conventionally, various proposals have been made for problems caused by such probing marks. For example, Patent Document 1 proposes a method of covering a probing mark on an electrode pad with a thick insulating film. Further, Patent Document 2 proposes a method in which the protruding portion of the probing mark is not in contact with the sealing resin by covering the probing mark of the electrode pad with a rewiring pattern. Patent Document 3 proposes a method in which a photosensitive resin is provided under the probing marks of the electrode pad and a plurality of electrode films are provided on the probing marks. Further, Patent Document 4 proposes a method for removing foreign matter on the electrode pad.

JP 2008-235539 A (for example, paragraph 0023, FIG. 1) Japanese Patent Laying-Open No. 2010-50224 (for example, paragraph 0024, FIG. 2) JP 2009-49297 A (for example, paragraph 0032, FIG. 12) JP-A-4-367295 (for example, paragraph 0011, FIG. 1)

  However, the method disclosed in Patent Document 1 has a problem in that warping and cracking are likely to occur in the semiconductor wafer because the stress generated in the semiconductor wafer is increased by increasing the thickness of the insulating film.

  In the method disclosed in Patent Document 2, since the position of the probing mark is not constant, it may not be reliably covered with the rewiring pattern, and when the thickness of the rewiring pattern is insufficient, the probing is performed. There is a problem that the protruding portion of the trace may break the rewiring pattern.

  In the method disclosed in Patent Document 3, the manufacturing process such as formation of a photosensitive resin layer and formation of a plurality of electrode films becomes very complicated, and a post made of an electrode material on an uneven probing mark. Therefore, there is a problem that it is difficult to obtain good connectivity between the electrode pad and the electrode material thereon.

  In the method disclosed in Patent Document 4, foreign matter on the electrode pad is polished and removed in a state where the substrate and the electrode pad are exposed, so that there is a problem that the electrode pad and circuit elements in the substrate are easily damaged.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a method of manufacturing a semiconductor device and a semiconductor device that are less likely to cause problems due to protrusions on the surface of the electrode pad. It is to provide.

  The method for manufacturing a semiconductor device according to the present invention includes a first insulating film forming step of forming a first insulating film covering at least a part of the electrode pad on a substrate including an electrode pad having a protrusion on the surface. A removal treatment step for performing a treatment capable of removing a protruding portion from the surface of the first insulation film, and a second insulation on the first insulation film and the electrode pad after the removal treatment step. And a second insulating film forming step for forming a film.

  A semiconductor device according to the present invention includes a substrate, an electrode pad provided on the substrate and having a protrusion on the surface, and a first electrode formed on the substrate so as to cover at least a part of the electrode pad. It has an insulating film and a second insulating film formed on the first insulating film and the electrode pad so that the electrode pad is not exposed.

  According to the method for manufacturing a semiconductor device and the semiconductor device according to the present invention, it is difficult for a defect due to the protruding portion on the surface of the electrode pad of the semiconductor device to occur. is there.

It is a longitudinal section showing roughly the 1st process of the manufacturing method of the semiconductor device concerning an embodiment of the invention. It is a longitudinal cross-sectional view which shows schematically the 2nd process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the 3rd process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the 4th process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the 5th process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the 6th process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows schematically the 7th process of the manufacturing method of the semiconductor device which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows roughly 1 process of the manufacturing method of the semiconductor device of a 1st comparative example. It is a longitudinal cross-sectional view which shows roughly 1 process of the manufacturing method of the semiconductor device of a 2nd comparative example. It is a longitudinal section showing roughly one process of a manufacturing method of a semiconductor device of the 3rd comparative example.

  1 to 7 are longitudinal sectional views schematically showing from the first step to the seventh step of the semiconductor device manufacturing method according to the embodiment of the present invention. 1 to 7 show a longitudinal section of a part of the semiconductor wafer.

  In the method of manufacturing a semiconductor device according to the embodiment, as shown in FIG. 1, first, an electrode pad 2 and a passivation film (PV film) 3 are formed on a semiconductor wafer 1 as an example of a substrate. The semiconductor wafer 1 has an integrated circuit including circuit elements such as transistors, capacitors, and resistance elements, and wiring. As the semiconductor wafer 1, a silicon wafer or a gallium arsenide wafer can be used. The electrode pad 2 is electrically connected to an integrated circuit in the semiconductor wafer 1, and is made of, for example, aluminum (Al), copper (Cu), Al—Si alloy, Al—Si—Cu alloy, or the like. The The electrode pad 2 can be formed by, for example, a plating method or a vapor deposition method. The PV film 3 is, for example, a silicon nitride film, and makes it difficult to cause mechanical damage, chemical damage, electrical damage, or the like to the semiconductor wafer 1. The PV film 3 can be formed by, for example, a vapor deposition method. In the first step shown in FIG. 1, the electrode pad 2 exposes the surface (upper surface) from the opening of the PV film 3.

  Next, as shown in FIG. 2, a probing needle (probe pin) 101 of a probing apparatus as an inspection apparatus is brought into contact with the electrode pad 2 so that the integrated circuit in the semiconductor wafer 1 is a good product or a defective product. A certain test (for example, operation check) is performed, and then the probing needle 101 is released from the electrode pad 2. This process is called a probing process or an inspection process. The probing needle 101 is made of, for example, tungsten (W). By the contact of the probing needle 101 at this time, a probing mark (probe mark) 21 including a protruding portion is formed on the surface of the electrode pad 2 formed of a material softer than the probing needle 101. . There are various shapes and sizes of the probing mark 21. For example, as shown in FIG. 2, the probing mark 21 having the protruding portion 22 may be formed.

  Next, as shown in FIG. 3, the first insulating film 4 covering at least a part of the electrode pad 2 is formed on the substrate 1 including the electrode pad 2 on which the probing mark 21 is present. In FIG. 3, the first insulating film 4 covers a portion other than the protruding portion 22 of the probing mark 21. As a material of the first insulating film 4, for example, polyimide can be used. Further, as the material of the first insulating film 4, other insulating materials such as polybenzoxazole (PBO) can be used. The thickness of the first insulating film 4 is one third to two of the final insulating film (here, the total thickness of the first insulating film 4 and the second insulating film 5). The thickness is about one-half, and is usually 2 to 20 [μm]. As shown in FIG. 3, the protruding portion 22 of the probing mark 21 may be exposed. Note that the first insulating layer 4 may be composed of a plurality of stacked insulating layers.

  Next, as shown in FIG. 4, a removal process step is performed that can remove the portion 22 of the probing mark 21 protruding above the first insulating film 4. As the removal processing step, a step of removing the protruding portion 22 by etching or a step of mechanically polishing and removing the protruding portion 22 by the polishing apparatus 102 can be employed. When the removal process step is performed by an etching process, there is an advantage that damage to the first insulating film 4 is small. Further, when the removal process step is performed by a polishing process, damage to the first insulating film 4 increases, but the protruding portion 22 can be quickly removed.

  Next, as shown in FIG. 5, the second insulating film 5 is formed on the upper surface of the portion of the electrode pad 2 where the probing marks 21 are present after undergoing the first insulating film 4 and the removal treatment step. . As a material of the second insulating film 5, for example, polyimide can be used. Further, as the material of the second insulating film 5, other insulating materials such as PBO can be used. The second insulating film 5 can be formed of the same material as the first insulating film 4. When the first and second insulating films 3 and 4 are thermosetting resins, a curing process is performed in a curing furnace at this stage. The set film thickness of the first and second insulating films 3 and 4 is adjusted so as to have a value after the curing process. One or more other insulating layers may be formed on the second insulating layer 6.

  Next, as shown in FIG. 6, after the second insulating film formation step, an opening 51 that penetrates the second insulating film 5 and the first insulating film 4 and reaches the upper surface of the electrode pad 2 is formed. . The opening 51 can be formed using, for example, a photolithography technique. Next, a rewiring layer (rewiring pattern) 6 that is electrically connected to the electrode pad 2 through the opening 51 is formed. The rewiring layer 6 can be made of, for example, Cu or an alloy containing Cu as a main component by, for example, a plating method. In addition, the formation of the opening 51 includes the step of providing the first opening in the first insulating film 4 after the removal processing step of the protruding portion 23 shown in FIG. 4, and the second insulating film 5 shown in FIG. This may be performed by two steps of forming a second opening connected to the first opening in the second insulating film 5 after the formation. As shown in FIG. 6, when the formation of the opening 51 is performed in one process, the number of manufacturing processes can be reduced, and the positional deviation that may occur when the formation of the opening is performed in a plurality of processes. There is an advantage that the possibility of.

  Next, as shown in FIG. 7, a mold resin layer 7 is formed as a sealing layer to cover the rewiring layer 6 so that a part (reference numeral 71) of the rewiring layer 6 is exposed. A columnar electrode 8 connected to the electrode and a solder ball 9 as an external connection electrode formed on the columnar electrode 8 are formed.

  According to the manufacturing method and semiconductor device of the semiconductor device according to the present embodiment described above, the protruding portion 22 of the probing mark 21 is removed after the first insulating film 4 is formed. WL-CSP processing can be performed without damaging the circuit (underlying device). For this reason, according to the semiconductor device manufacturing method and the semiconductor device according to the present embodiment, it is possible to reduce the incidence of defective products due to the probing marks 21 of the electrode pads 2.

  In addition, according to the method of manufacturing a semiconductor device and the semiconductor device according to the present embodiment, two layers of insulating films are formed, and there are no protruding portions on the second insulating film 5. , 5 is less likely to generate pinholes at the same position, and therefore, there is an advantage that the generation of pinholes penetrating the entire insulating films 8 and 9 is extremely small.

  In the above description, the case where the protruding portion (projecting portion) 22 is a probing mark has been described. However, in the present invention, the protruding portion (projecting portion) 22 is caused by a cause other than probing. It is also applicable to.

  FIG. 8 is a longitudinal sectional view schematically showing one step of the method for manufacturing the semiconductor device of the first comparative example. In FIG. 8, parts that are the same as or correspond to those in the configuration of the semiconductor device in FIG. The first comparative example shows a situation where the rewiring layer 206 is disconnected when the removal processing step of the protruding portion of the probing mark 21 is not performed. As already described, according to the method of manufacturing a semiconductor device and the semiconductor device according to the present embodiment, the portion 22 protruding from the first insulating film 4 of the probing mark 21 is removed. The rewiring layer 6 is not disconnected by the probing mark 21.

  FIG. 9 is a longitudinal sectional view schematically showing one step of the method for manufacturing the semiconductor device of the second comparative example. 9, parts that are the same as or correspond to those in the semiconductor device in FIG. 6 (the embodiment) are denoted by the same reference numerals. The second comparative example shows a case where the entire protruding portion of the probing mark 21 is covered with a thick insulating layer 304 and a rewiring layer 306 is formed thereon. However, in this case, since the stress generated in the semiconductor wafer as the substrate 1 is increased by increasing the thickness of the insulating film 304, there is a problem that warpage and cracks are likely to occur in the semiconductor wafer. According to the method for manufacturing a semiconductor device and the semiconductor device according to the present embodiment, the portion 22 protruding from the first insulating film 4 of the probing mark 21 is removed, so the first insulating film 4 and the second insulating film 4 are removed. Since the total thickness with the insulating film 5 (film thickness A in FIG. 7) can be reduced, warpage and cracks are unlikely to occur in the semiconductor wafer.

  FIG. 10 is a longitudinal sectional view schematically showing one step of the method for manufacturing the semiconductor device of the third comparative example. 10, parts that are the same as or correspond to those in the semiconductor device in FIG. 6 (embodiment) are denoted by the same reference numerals. In the third comparative example, the protruding portion of the probing mark 21 of the electrode pad 2 is placed in the opening 405 of the insulating layer 404, and the protruding portion is covered with the rewiring layer 406. Proposes a way to avoid contact. However, since the positions of the protruding portions of the probing marks of the electrode pads 2 arranged in large numbers on the semiconductor wafer are not constant, it is difficult to reliably cover them with the rewiring pattern. According to the method of manufacturing a semiconductor device and the semiconductor device according to the present embodiment, since the portion 22 protruding from the first insulating film 4 of the probing mark 21 is removed, the protruding portion of the probing mark 21 is removed. This is advantageous in that the manufacturing process is not complicated because a difficult processing step is not required to place the protruding portion in the opening 405 of the insulating layer 404 and cover the protruding portion with the rewiring layer 406.

  DESCRIPTION OF SYMBOLS 1 Semiconductor wafer, 2 Electrode pad, 3 Passivation film (PV film), 4 1st insulating film, 5 2nd insulating film, 6 Rewiring layer (rewiring pattern), 7 Mold resin (sealing layer), 8 Columnar electrode, 9 solder ball, 21 probing mark (probe mark), 22 protruding part, 23 part protruding above the first insulating film, 71 opening, 101 probing needle (probe pin).

Claims (14)

A first insulating film forming step of forming a first insulating film covering at least a part of the electrode pad on a substrate including an electrode pad having a protrusion on the surface;
A removal treatment step of performing a treatment capable of removing a portion protruding from the surface of the first insulating film;
And a second insulating film forming step of forming a second insulating film on the first insulating film and the electrode pad after the removing treatment step.   The method of manufacturing a semiconductor device according to claim 1, wherein the protruding portion of the electrode pad is a probing mark.   3. The method according to claim 1, further comprising an inspection step including an operation of bringing a probing needle into contact with the electrode pad before the first insulating film forming step and then separating the probing needle from the electrode pad. The manufacturing method of the semiconductor device as described in any one of Claims 1-3. The protruding portion is a part of the protruding portion of the electrode pad,
The method of manufacturing a semiconductor device according to claim 1, wherein the removing treatment step includes a step of removing the protruding portion by etching. The protruding portion is a part of the protruding portion of the electrode pad,
The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the removal processing step includes a step of removing the protruding portion by polishing. A step of forming an opening reaching the electrode pad through the first insulating film and the second insulating film after the second insulating film forming step;
The method of manufacturing a semiconductor device according to claim 1, further comprising: forming a rewiring layer that is electrically connected to the electrode pad through the opening. Forming a first opening that penetrates the first insulating film and reaches the electrode pad between the first insulating film forming step and the second insulating film forming step;
A step of forming a second opening penetrating the second insulating film and connected to the first opening after the second insulating film forming step;
The method further comprises: forming a redistribution layer that is electrically connected to the electrode pad through the second opening and the first opening. The manufacturing method of the semiconductor device as described in any one of Claims 1-3. Forming a sealing layer covering the rewiring layer;
The method of manufacturing a semiconductor device according to claim 6, further comprising: forming an electrode portion electrically connected to the redistribution layer and provided on the sealing layer. A substrate,
An electrode pad provided on the substrate and having a protrusion on the surface;
A first insulating film formed on the substrate so as to cover at least a part of the electrode pad;
A semiconductor device comprising: the first insulating film and a second insulating film formed on the electrode pad so that the electrode pad is not exposed.   The semiconductor device according to claim 9, wherein the protruding portion of the electrode pad is a probing mark. An opening that penetrates the first insulating film and the second insulating film and reaches the electrode pad;
The semiconductor device according to claim 9, further comprising a rewiring layer electrically connected to the electrode pad through the opening. The semiconductor device according to claim 9, wherein the protruding portion of the electrode pad does not have a portion higher than a surface of the first insulating film. The semiconductor device according to claim 10, wherein the protruding portion of the electrode pad is sealed with the second insulating film. A sealing layer covering the rewiring layer;
The semiconductor device according to claim 9, further comprising: an electrode part electrically connected to the redistribution layer and provided on the sealing layer.

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