JP5145000B2 - Penetration wiring substrate, semiconductor package, and method of manufacturing penetration wiring substrate - Google Patents

Description

  The present invention relates to a through wiring substrate, a semiconductor package, and a method for manufacturing the through wiring substrate.

As a conventional method for manufacturing a through wiring substrate, for example, the following method can be cited (for example, see Patent Document 1). Hereinafter, a description will be given with reference to FIGS. 6 and 7.
First, as shown in FIG. 6A, a pattern of a photoresist 108 is formed on a Si substrate 101 bonded to a support such as a glass plate, and then a through-hole is formed in the Si substrate 101 using a dry etching method. 107 is formed.
Next, as shown in FIG. 6B, after the photoresist 108 is removed, an insulating layer 109 is formed using a CVD method.

Next, as shown in FIG. 7A, the insulating layer 109 located at the bottom of the through hole 107 is removed by using a dry etching method to expose the electrode portion 106 of the device, and then the barrier layer is formed by a sputtering method. 116 and a seed layer 117 for electrolytic plating are formed.
Next, as shown in FIG. 7B, a wiring layer is grown by electrolytic plating, the wiring part 111 is formed using photolithography and wet etching, and then a solder bump 112 is mounted.

  However, in such a conventional method, the step of forming a barrier layer and a seed layer for electrolytic plating by a sputtering method becomes a problem. That is, when the barrier layer and the seed layer are formed inside the through hole by sputtering, the seed layer formed on the barrier layer has a tendency to be discrete in an island shape rather than a column shape. That is, since there is a portion where the seed layer does not partially grow on the barrier layer, it is difficult to obtain sufficient adhesion between the barrier layer and the seed layer. As a result, peeling is likely to occur at the boundary between the barrier layer and the seed layer, and there is a possibility that the reliability of the through electrode portion is reduced and the electrical contact resistance is increased. The decrease in adhesion between the barrier layer and the seed layer when using sputtering is considered to occur due to the following phenomenon. Hereinafter, a description will be given with reference to FIG.

  First, when a barrier layer is to be formed in the through hole by sputtering, the sputtered particles 115 of the barrier layer material are obliquely incident on the side wall of the through hole. When the sputtered particles 111 are incident in an oblique direction, the film at the initial stage of growth serves as a mask for blocking the sputtered particles, and a portion where the sputtered particles are difficult to hit is formed on the substrate. As a result, the surface of the grown film has a columnar shape with many gaps and a rough structure [see FIG. 8A].

When the seed layer is continuously formed on the barrier layer 116 by sputtering, the surface shape of the barrier layer 116 serves as a mask, so that a portion where the sputtered particles of the seed layer do not enter the surface of the barrier layer 116 is formed. End up. As a result, the boundary between the barrier layer 116 and the seed layer 117 has a structure with many gaps, and the adhesion between the two layers is extremely low [see FIG. 8B]. As described above, in the conventional seed layer formation method using the sputtering method, it is very difficult to improve the structural defect between the barrier layer 116 and the seed layer 117.
JP 2005-235858 A

The present invention has been devised in view of such a conventional situation, and reduces the gap generated at the boundary between the barrier layer and the seed layer, improves the adhesion between the two layers, and improves the reliability of the through electrode portion. A first object is to provide an excellent through wiring substrate.
It is a second object of the present invention to provide a semiconductor package having a through wiring substrate with improved adhesion between the two layers of the barrier layer and the seed layer and having excellent through electrode portion reliability. .
Furthermore, the present invention spreads the seed layer formed by electroless plating over the entire surface of the barrier layer, reduces the gap generated at the boundary between the barrier layer and the seed layer, and improves the adhesion between the two layers. It is a third object to provide a method for manufacturing a through wiring board with excellent reliability of electrode portions.

Through wiring board according to claim 1 of the present invention includes a base plate, an electrode portion disposed on one side of the substrate, reached from the other surface side of the front Kimoto plate on one side A through-wiring board comprising at least a through-hole that exposes a part of the electrode portion and an electroplating layer that is arranged on the insulated inner surface of the through-hole via a seed layer The seed layer is composed of a first metal layer and a second metal layer disposed on the first metal layer, and the first metal layer is a film having a columnar shape, and the columnar shape However, it has directivity toward the opening side of the through hole.
According to a second aspect of the present invention, there is provided the through wiring substrate according to the first aspect, wherein the substrate is a semiconductor substrate, and an insulated inner surface of the through hole is an insulating film.

The semiconductor package of claim 3 of the present invention includes a base plate, led an electrode portion disposed on one side of the substrate, from the other surface side of the front Kimoto plate on one side distribution At least a through hole exposing a part of the electrode part, and an electrolytic plating layer disposed on an insulated inner surface of the through hole via a seed layer, wherein the seed layer is a first layer The first metal layer is a coating having a columnar shape, and the columnar shape is on the opening side of the through hole. At least a through wiring board having directivity toward the surface, and a support body disposed on one surface side of the through wiring board via a resin.
According to a fourth aspect of the present invention, in the semiconductor package according to the third aspect, the substrate is a semiconductor substrate, and the insulated inner surface of the through hole is an insulating film.

Method for producing a through-wiring board according to claim 5 of the present invention includes a base plate, an electrode portion disposed on one side of the substrate, one surface from the other surface side of the front Kimoto plate A through hole that extends to the side and exposes a part of the electrode portion; and an electroplating layer that is disposed on the insulated inner surface of the through hole via a seed layer, and the seed layer Is composed of a first metal layer and a second metal layer disposed on the first metal layer, and the first metal layer is a film having a columnar shape, and the columnar shape is formed through the through-hole. A method of manufacturing a through wiring substrate having directivity toward an opening side of a hole, wherein the seed layer overlaps the first metal layer and a first step of forming the first metal layer by a sputtering method. And a second step of forming a second metal layer by a plating method.
According to a sixth aspect of the present invention, there is provided a through wiring substrate manufacturing method according to the fifth aspect , wherein the first step uses a long throw sputtering method or a collimated sputtering method.
According to claim 7 of the present invention, in the method for manufacturing a through wiring substrate according to claim 5 or 6, the semiconductor substrate is used as the substrate, and the insulating film is used as an insulated inner surface of the through hole. Features.

  In the present invention, the seed layer is composed of a first metal layer and a second metal layer disposed on the first metal layer, and the first metal layer is a film having a columnar shape, Since the columnar shape has directivity toward the opening side of the through hole, the columnar shape constituting the first metal layer is closely adjacent. Therefore, in the second metal layer disposed on the first metal layer, the gap generated at the boundary between these two layers is greatly reduced. Therefore, since the adhesion between the two layers is remarkably improved, it is possible to provide a through wiring substrate with excellent through electrode portion reliability.

  In addition, according to the present invention, it is possible to provide a semiconductor package that includes the through wiring substrate in which the adhesion between the first metal layer and the second metal layer is improved and is excellent in the reliability of the through electrode portion.

  Furthermore, in the present invention, the seed layer is formed by a first step of forming a first metal layer by a sputtering method, and a second step of forming a second metal layer by a plating method so as to overlap the first metal layer. Make it. Therefore, first, the first metal layer has a columnar structure by sputtering, and the columnar structure can be formed as a coating film having directivity toward the opening. Therefore, the first metal layer can have a form in which the columnar structures are closely adjacent. Since the second metal layer is formed by plating to cover the entire surface of the first metal layer in such a form, the gap generated at the boundary between the first metal layer and the second metal layer is greatly reduced. it can. Therefore, since the adhesion between the two layers is improved, it is possible to provide a method for manufacturing a through wiring substrate with excellent reliability of the through electrode portion. In particular, in the first step, the effect can be made more reliable by using a long throw sputtering method or a collimated sputtering method.

  Hereinafter, an embodiment of a through wiring board and a semiconductor package according to the present invention will be described with reference to the drawings.

FIG. 1A is a schematic cross-sectional view showing an embodiment of a through wiring board according to the present invention, and FIG. 1B is a seed of a through electrode constituting the through wiring board in FIG. It is typical sectional drawing which expands and shows a layer part.
As shown in FIG. 1A, the through wiring substrate 10 includes a semiconductor substrate 11, a functional element 12 on one surface side of the semiconductor substrate 11, a wiring portion 13 and an electrode portion 14 connected thereto. And a through electrode 15 that electrically connects the other surface and the electrode portion 14. The through electrode 15 is arranged from the other surface side of the semiconductor substrate 11 to the one surface side, and exposes a part of the electrode portion 14. An insulating film is formed on the inner surface of the through hole 16. 17 and an electroplating layer 19 disposed through a seed layer 18.

  In the through wiring board 10 of the present invention, as shown in FIG. 1B, the seed layer 18 is composed of a first metal layer 18a and a second metal layer 18b arranged to overlap the first metal layer 18a. The first metal layer 18 a is a film having a columnar shape, and the columnar shape has directivity toward the opening side of the through hole 16.

  In the present invention, the first metal layer 18 a constituting the seed layer 18 is a film having a columnar shape, and the columnar shape has directivity toward the opening side of the through-hole 16, so that the first metal The columnar shape constituting the layer 18a is closely adjacent. Therefore, in the second metal layer 18b disposed on the first metal layer 18a, the gap generated at the boundary between these two layers is greatly reduced. Therefore, since the adhesion between the two layers is remarkably improved, it is possible to provide the through wiring substrate 10 having excellent reliability of the through electrode portion.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the semiconductor package of the present invention provided with the through wiring board 10 as described above.
In this semiconductor package 1, a through wiring board 10 and a support body 20 that is disposed on one surface side of the through wiring board 10 via a bonding resin and forms a cap substrate are bonded using a bonding resin 30. It is configured.

  In the present invention, as described above, in the through wiring substrate 10, the first metal layer 18 a constituting the seed layer 18 is a film having a columnar shape, and the columnar shape is directed toward the opening side of the through hole 16. By having directivity, the gap between the first metal layer 18a and the second metal layer 18b can be eliminated, and the adhesion between the two layers can be improved. Thereby, the reliability of the through electrode portion in the through wiring substrate 10 can be improved. And the semiconductor package 1 of this invention provided with such a penetration wiring board 10 becomes the thing excellent in reliability.

Next, an example of a method for manufacturing the through wiring substrate and the semiconductor package will be described with reference to the drawings.
3 and 4 are cross-sectional process diagrams illustrating a method of manufacturing a semi-through wiring substrate according to the present invention.
First, as shown in FIG. 3 (a), a desired functional element 12 such as an optical device and a wiring part 13 and an electrode part 14 necessary for connection are formed on a surface of a semiconductor substrate 11 such as silicon, by a normal semiconductor manufacturing process. Form using.

  As the wiring part 13 and the electrode part 14, it is excellent in electroconductivity, such as aluminum (Al), copper (Cu), an aluminum-silicon (Al-Si) alloy, an aluminum-silicon-copper (Al-Si-Cu) alloy, for example. Although materials are preferably used, these materials are easily oxidized.

  Next, as shown in FIG. 3B, a mask 5 is formed on the other surface of the semiconductor substrate 11. As the mask 5, for example, UV curable resin or polyimide photosensitive resin is used, and the opening 5 a is provided at a predetermined position by photolithography. Here, the opening 5a is for squeezing the fine hole 16 for forming the wiring structure, and is formed as a circular small hole at a position corresponding to the electrode part 14, for example.

Next, as shown in FIG. 3C, the semiconductor substrate 11 at the position of the opening 5a is etched using the mask 5 by using, for example, reactive ion etching (DRIE) method or the like. Then, the fine holes 16 are formed. By using the DRIE method, it is possible to perform drilling with high accuracy. The DRIE method uses sulfur hexafluoride (SF ₆ ) as an etching gas, and alternately etches by high-density plasma and passivation film on the sidewall (Bosch process), thereby deep etching the silicon substrate. It is. Thereafter, as shown in FIG. 3D, the mask 5 is peeled off if necessary.

The micro hole 16 is not limited to a circle, and may have any size as long as the contact area with the electrode portion 14 can be secured, and the shape may be any shape such as an ellipse, a rectangle, a triangle, and a rectangle.
Further, the method for forming the micro holes 16 is not limited to the DRIE method, and a wet etching method using a potassium hydroxide (KOH) aqueous solution or the like may be used.

Next, as shown in FIG. 3E, an insulating film 17 is formed on the entire surface of the substrate. As the insulating film 17, silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), phosphorus silicate glass (PSG), boron phosphorus silicate glass (BPSG), or the like can be used, and depending on the use environment of the semiconductor package. Just choose. SiO ₂ and Si ₃ N ₄ can be formed into any thickness by using CVD. In order to form the insulating film 17 made of SiO ₂ , for example, it can be formed by a plasma CVD method using silane or tetraethoxysilane (TEOS) as a raw material.

Next, as shown in FIG. 4A, the insulating film 17 at the bottom of the fine hole 16 is removed using dry etching, and a part of the surface of the electrode portion 14 is exposed. Further, when etching SiO ₂ , a reactive ion etching (RIE) method using carbon tetrafluoride (CF ₄ ) can be used.

Next, as shown in FIG. 4B, a seed layer 18 is formed in the microhole 16. In the present invention, the seed layer 18 includes a first step of forming the first metal layer 18a by a sputtering method, and a second step of forming a second metal layer 18b by a plating method so as to overlap the first metal layer 18a. It is produced by two steps. Hereinafter, each step will be described in detail.
First, as shown in FIG. 5A, a first metal layer 18a is formed in the micro holes 16 using a sputtering method (first step).

  The first metal layer 18a is formed using a sputtering method. As a material of the first metal layer 18a, for example, Ti, TiN, TiW, Cr, Ta, TaN or the like is used. As a sputtering method, a long throw sputtering method, a collimated sputtering method, an ion beam sputtering method, a bias sputtering method, or the like can be used, but a long throw sputtering method or a collimated sputtering method with high directivity of the sputtered particles 21 is used. Is preferred. By increasing the directivity of the sputtered particles by these methods, it is possible to increase the film formation efficiency in the hole.

Further, when the sputtered particles 21 having high directivity are incident on the inclined substrate, the film at the initial stage of growth tends to be a mask for blocking the sputtered particles, and the surface of the grown film is columnar and is more than when a general sputtering method is used. Also has a large surface area. If this principle is used, the first metal layer 18a having a large surface area can be formed on the side wall in the through hole. Further, if the substrate temperature when forming the first metal layer 18a is 200 ° C. or less, the movement of sputtered particles on the surface of the through hole 16 is reduced, and the film growth in the columnar shape is facilitated.
Thus, a first metal layer 18 a which is a film having a columnar shape and has directivity toward the opening side of the through hole 16 is formed. Therefore, the first metal layer 18a can be in a form in which the columnar structures are closely adjacent.

Next, as shown in FIG. 5B, the second metal layer 18b is formed so as to overlap the first metal layer 18a by using a plating method (second step).
After forming the first metal layer 18a, the second metal layer 18b is formed by electroless plating. As the material of the first metal layer 18a, a conductive material such as copper is used.

As a method for forming the second metal layer 18b, sputtering is generally used. However, when the film is formed by sputtering as described above, the surface roughness of the first metal layer 18a is reduced to the second metal layer 18b. Can not fill enough. Therefore, it is necessary to perform electroless plating after sputter deposition of the first metal layer 18a.
By combining the first metal layer 18a having a large surface area and the electroless plating method as described above, the gap generated at the boundary between the first metal layer and the second metal layer can be greatly reduced. Therefore, since the adhesion between the two layers is improved, the reliability of the through electrode portion can be improved.

Next, as shown in FIG. 4C, an electrolytic plating layer 19 made of a conductor is formed in the micro holes 16 using an electrolytic plating method. The conductor is not particularly limited as long as it is a good electrical conductor. For example, in addition to copper, aluminum, nickel, chromium, silver, tin, etc. having a low electrical resistance, alloys such as Au—Sn, Sn—Pb, or Sn A metal such as a solder alloy such as a group, a Pb group, an Au group, an In group, or an Al group can be used.
As described above, the semiconductor through wiring substrate 10 shown in FIG. 1 is obtained.

  Further, in order to manufacture the semiconductor package 1 shown in FIG. 2, as shown in FIG. 4D, the semiconductor penetrating wiring substrate 10 and the support body 20 serving as a cap material are bonded using a bonding resin 30. Join. At this time, the support element 20 is put on and bonded so that the functional element 12 is inside and does not contact the functional element 12. The support 20 can also be a semiconductor substrate such as silicon. Examples of the bonding resin 30 include a photosensitive or non-photosensitive liquid resin (such as a UV curable resin, a visible light curable resin, an infrared light curable resin, and a thermosetting resin) and a dry film. As the type of resin, epoxy resin, silicon resin, acrylic resin, polyimide resin, or the like can be used, and may be appropriately selected according to the use environment of the semiconductor package.

In order to form the bonding resin 30, for example, a liquid resin can be applied at a predetermined position by a printing method, or a dry film can be attached and patterned by leaving a predetermined position by a photolithography technique. .
As described above, the semiconductor package 1 shown in FIG. 2 is obtained.

  The through wiring board and the semiconductor package thus obtained can improve the adhesion between the two layers by eliminating a gap generated at the boundary between the first metal layer and the first metal layer in the production of the seed layer. As a result, the through electrode portion is excellent in reliability.

  The through wiring substrate, the semiconductor package, and the through wiring substrate manufacturing method of the present invention have been described above. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention. It is.

  The present invention can be widely applied to a through wiring substrate having a through electrode, a semiconductor package, and a method for manufacturing the through wiring substrate.

It is sectional drawing which shows an example of the penetration wiring board which concerns on this invention. It is sectional drawing which shows an example of the semiconductor package of this invention. It is sectional drawing which shows an example of the manufacturing method of the penetration wiring board which concerns on this invention in process order. It is sectional drawing which shows the process following FIG. 3 in order. FIG. 5 is a cross-sectional view for explaining in detail a method for producing the seed layer shown in FIG. It is a schematic cross section which shows an example of the manufacturing method of the conventional penetration wiring board in order of a process. FIG. 7 is a cross-sectional view sequentially illustrating processes subsequent to FIG. 6. FIG. 8 is a cross-sectional view for explaining in detail a method for producing the seed layer shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Semiconductor package, 10 Through wiring board, 11 Semiconductor substrate, 12 Functional element, 13 Wiring part, 14 Electrode part, 15 Through electrode, 16 Through hole, 17 Insulating film, 18 Seed layer, 18a 1st metal layer, 18b 2nd Metal layer, 19 electroplating layer, 20 bonding resin, 21 sputtered particle 30 support.

Claims (7)

A base plate, an electrode portion disposed on one side of the substrate,
Disposed reached from the other surface side of the front Kimoto plate on one side, a through hole exposing a portion of the electrode portion,
A through-wiring board comprising at least an electroplating layer disposed via a seed layer on an insulated inner surface of the through-hole,
The seed layer is composed of a first metal layer and a second metal layer arranged on the first metal layer, and the first metal layer is a film having a columnar shape, and the columnar shape is A through wiring substrate having directivity toward the opening side of the through hole. The through wiring substrate according to claim 1, wherein the substrate is a semiconductor substrate, and an insulated inner surface of the through hole is an insulating film. A base plate, an electrode portion disposed on one side of the substrate,
Disposed reached from the other surface side of the front Kimoto plate on one side, a through hole exposing a portion of the electrode portion,
An electroplating layer disposed through a seed layer on the insulated inner surface of the through-hole,
The seed layer is composed of a first metal layer and a second metal layer arranged on the first metal layer, and the first metal layer is a film having a columnar shape, and the columnar shape is A semiconductor device comprising at least a through wiring substrate having directivity toward the opening side of the through hole, and a support disposed on one surface side of the through wiring substrate via a resin. package. The semiconductor package according to claim 3, wherein the substrate is a semiconductor substrate, and an insulated inner surface of the through hole is an insulating film. A base plate, an electrode portion disposed on one side of the substrate,
Disposed reached from the other surface side of the front Kimoto plate on one side, a through hole exposing a portion of the electrode portion,
An electroplating layer disposed through a seed layer on the insulated inner surface of the through-hole,
The seed layer is composed of a first metal layer and a second metal layer arranged on the first metal layer, and the first metal layer is a film having a columnar shape, and the columnar shape is A method for manufacturing a through wiring board having directivity toward the opening side of the through hole,
The seed layer is produced by a first step of forming a first metal layer by a sputtering method and a second step of forming a second metal layer by a plating method so as to overlap the first metal layer. A manufacturing method of a through wiring board characterized by 6. The method for manufacturing a through wiring substrate according to claim 5 , wherein the first step uses a long throw sputtering method or a collimated sputtering method. 7. The method of manufacturing a through wiring substrate according to claim 5, wherein a semiconductor substrate is used as the substrate, and an insulating film is used as an insulated inner surface of the through hole.

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