JP7327535B2 - Penetration electrode substrate - Google Patents

Description

The present invention relates to a through electrode substrate, a manufacturing method thereof, and a semiconductor device using the through electrode substrate.

2. Description of the Related Art In recent years, the development of a three-dimensional mounting technology in which semiconductor chips having integrated circuits are stacked vertically is being developed. The three-dimensional mounting technology is a technology for reducing the area occupied by a semiconductor chip in the plane direction by stacking a plurality of semiconductor chips in the thickness direction of the semiconductor chip. Through electrodes are used as three-dimensional wiring in such three-dimensional mounting technology. For example, Japanese Unexamined Patent Application Publication No. 2002-100000 discloses a technique of forming a through electrode by providing a through hole in a semiconductor chip and filling the inside of the through hole with a conductive layer to electrically connect both surfaces of the semiconductor chip. .

However, in the invention (filling type) disclosed in Patent Document 1 in which the conductive layer is filled inside the through hole, there is a problem that it takes time to fill the conductive layer inside the through hole. Therefore, for example, Patent Document 2 discloses an invention (non-filling type) that shortens the process and improves productivity by forming a conductive layer only on the side wall of a through hole.

Japanese Patent Application Laid-Open No. 2006-222138 JP 2013-54213 A

The non-filled through electrode disclosed in Patent Document 2 can shorten the process and improve productivity compared to the filled through electrode disclosed in Patent Document 1. However, in the non-filled type through electrode, if the conductive layer peels off on the side wall of the through hole, defective conduction occurs. Therefore, the adhesion between the side wall of the through hole and the conductive layer is important. In particular, for through electrodes with a high aspect ratio, it is difficult to ensure sufficient adhesion of the conductive layer formed on the side wall of the through hole, and further investigation is required.

An object of the present invention is to improve adhesion of a conductive layer in a through-hole in a through-electrode substrate.

A method for manufacturing a through electrode substrate according to an embodiment of the present invention has a first surface and a second surface opposite to the first surface, and a through hole passing through the first surface and the second surface. The formed substrate is prepared, the first conductive adhesion layer is formed on the first surface and part of the side wall of the through hole on the first surface side by a sputtering method, and after forming the first conductive adhesion layer, the first conductive adhesion layer is formed. A second conductive adhesion layer is formed by a sputtering method on the second surface and part of the second surface side of the side wall of the through hole, is in contact with the first conductive adhesion layer and the second conductive adhesion layer, and is in contact with the first conductive adhesion layer. A seed layer is formed in contact with the conductive adhesion layer and the side wall of the through hole exposed from the second conductive adhesion layer, and electroplating is performed to supply power to the seed layer to form a conductive layer on the seed layer.

According to this method for manufacturing a through electrode substrate, it is possible to increase the adhesion of the conductive layer inside the through hole in the through electrode substrate.

A method for manufacturing a through electrode substrate according to an embodiment of the present invention has a first surface and a second surface opposite to the first surface, and a through hole passing through the first surface and the second surface. The formed substrate is prepared, the first conductive adhesion layer is formed on the first surface and part of the side wall of the through hole on the first surface side by a sputtering method, and after forming the first conductive adhesion layer, the first conductive adhesion layer is formed. A second conductive adhesion layer is formed by a sputtering method on the second surface and part of the second surface side of the side wall of the through hole, and after forming a third conductive adhesion layer on the first conductive adhesion layer, the second conductive adhesion layer is formed. Forming a fourth conductive adhesion layer on the conductive adhesion layer, contacting the third conductive adhesion layer and the fourth conductive adhesion layer, and forming a through hole exposed from the first to fourth conductive adhesion layers A seed layer made of the same material as the third conductive adhesion layer and the fourth conductive adhesion layer is formed in contact with the sidewall, and electroplating is performed to supply power to the seed layer to form a conductive layer on the seed layer.

In another preferred embodiment, the third conductive adhesion layer and the fourth conductive adhesion layer may be formed by sputtering.

According to this method for manufacturing a through electrode substrate, the adhesion of the conductive layer inside the through hole in the through electrode substrate can be further enhanced.

Moreover, in another preferred embodiment, an insulating filler may be formed in the through hole in which the conductive layer is formed.

According to this method for manufacturing a through electrode substrate, it is possible to enhance the sealing property in the through hole.

Also, in another preferred embodiment, the seed layer may be formed by oblique deposition.

According to this method for manufacturing a through electrode substrate, even in a through hole having a high aspect ratio, a seed layer can be formed on the side wall of the through hole between the first conductive adhesion layer and the second conductive adhesion layer. .

In another preferred aspect, in the oblique deposition, the angle between a line parallel to the flight direction of the deposition material and the normal to the first surface may be 5° or more and 20° or less.

According to this method for manufacturing a through electrode substrate, even in a through hole having a high aspect ratio, a seed layer can be formed on the side wall of the through hole between the first conductive adhesion layer and the second conductive adhesion layer. .

A through electrode substrate according to an embodiment of the present invention has a first surface and a second surface opposite to the first surface, and is provided with a through hole penetrating through the first surface and the second surface. a first conductive adhesion layer disposed on the first surface and a portion of the sidewall of the through hole on the first surface side; and a second surface and a portion of the sidewall of the through hole on the second surface side. a second conductive adhesion layer formed on the substrate; a seed layer disposed in contact with the first conductive adhesion layer, the second conductive adhesion layer, and the sidewall; and a conductive layer disposed on the seed layer.

According to this through electrode substrate, the adhesion of the conductive layer in the through hole in the through electrode substrate can be enhanced.

A through electrode substrate according to an embodiment of the present invention has a first surface and a second surface opposite to the first surface, and is provided with a through hole penetrating through the first surface and the second surface. a first conductive adhesion layer disposed on the first surface and a portion of the sidewall of the through hole on the first surface side; and a second surface and a portion of the sidewall of the through hole on the second surface side. a second conductive adhesion layer disposed on the first conductive adhesion layer; a third conductive adhesion layer disposed on the first conductive adhesion layer; a fourth conductive adhesion layer disposed on the second conductive adhesion layer; a seed layer disposed in contact with the conductive adhesion layer, the fourth conductive adhesion layer, and the sidewall and made of the same material as the third conductive adhesion layer and the fourth conductive adhesion layer; and a conductive layer disposed on the seed layer. and including.

According to this through electrode substrate, the adhesion of the conductive layer inside the through hole in the through electrode substrate can be further enhanced.

Also, in another preferred embodiment, an insulating filler may be placed in the through-hole in which the conductive layer is formed.

According to this through electrode substrate, it is possible to improve the sealing property in the through hole.

A semiconductor device according to an embodiment of the present invention includes the above-described through electrode substrate and two other substrates or chips that are laminated with the through electrode substrate therebetween and electrically connected.

A semiconductor device according to an embodiment of the present invention has the above through electrode substrate and another substrate or chip arranged side by side with the through electrode substrate.

ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of the conductive layer in the through-hole in a through-electrode substrate can be improved.

FIG. 4 is a top view illustrating through electrodes of the through electrode substrate according to the first embodiment of the present invention; 4 is a flow chart illustrating a method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate provided with through holes in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which an insulating layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a first conductive adhesion layer is formed from one side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 6 is a schematic diagram showing a cross section of a substrate on which a second conductive adhesion layer is formed from the other side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a seed layer is formed from one side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 6 is a schematic diagram showing a cross section of a substrate on which a seed layer is formed from the other side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a conductive layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a conductive layer is patterned in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a first photosensitive resin layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a second photosensitive resin layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which first and second photosensitive resin layers are patterned in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross section of a substrate on which a wiring layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a diagram showing another example of through holes in the through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a diagram showing another example of through holes in the through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a diagram showing another example of through holes in the through electrode substrate according to the first embodiment of the present invention; FIG. 2 is a schematic diagram of a film forming apparatus using oblique vapor deposition in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross-sectional view of a through electrode substrate on which a conductive layer is formed by oblique vapor deposition in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention; FIG. 8 is a schematic diagram showing a cross section of a substrate on which a conductive layer is formed in a method for manufacturing a through electrode substrate according to a second embodiment of the present invention; It is a figure which shows the semiconductor device which concerns on 3rd Embodiment of this invention. It is a figure which shows another example of the semiconductor device which concerns on 3rd Embodiment of this invention. It is a figure which shows another example of the semiconductor device which concerns on 3rd Embodiment of this invention.

<First embodiment>
Hereinafter, a method for manufacturing a through-hole substrate according to the first embodiment of the present invention will be described in detail with reference to the drawings. The embodiments shown below are examples of embodiments of the present invention, and the present invention should not be construed as being limited to these embodiments. In the drawings referred to in this embodiment, the same reference numerals or similar reference numerals may be assigned to the same parts or parts having similar functions, and repeated description thereof may be omitted. Also, the dimensional ratios in the drawings may differ from the actual ratios for the convenience of explanation, and a part of the configuration may be omitted from the drawings.

[Configuration of through electrode substrate 1]
FIG. 1 is a top view illustrating through electrodes of a through electrode substrate according to the first embodiment of the present invention. FIG. 13 shows a schematic diagram of a cross section along line AB in FIG. FIG. 1 is a view of the substrate 100 viewed from the first surface 101 side. First, the configuration of the through electrode substrate 1 will be described with reference to FIGS. 1 and 13. FIG.

In the substrate 100 in which the through holes 90 are formed, the through electrode substrate 1 electrically connects the first surface 101 side of the substrate 100 and the second surface 102 side opposite to the first surface through the through holes 90 . between the conductive layers 61, 62, 65 and the substrate 100, the insulating layers 71, 72, 75, the first conductive adhesive layers 11, 15, the second Conductive adhesion layers 22, 25 and seed layers 31, 32, 35 are formed.

In the following description, the insulating layers 71, 72, and 75 are used when referring to those located on the first surface 101, the second surface 102, and the side wall of the through hole 90, respectively, and are not distinguished from each other. may be referred to as an insulating layer 70 . The first conductive adhesion layers 11 and 15 are used when referring to those positioned on the first surface 101 and the side wall of the through hole 90, respectively. There is a case. In addition, the second conductive adhesion layers 22 and 25 are used when referring to those positioned on the second surface 102 and on the side wall of the through hole 90, respectively. Sometimes referred to as layer 20 .

The first conductive adhesion layer 10 and the second conductive adhesion layer 20 may be formed directly on the insulating layer 70, or may be formed via another intermediate layer (not shown). The seed layers 31, 32, and 35 are used when referring to layers positioned on the first surface 101, the second surface 102, and the side walls of the through hole 90, respectively. Sometimes referred to as layer 30 . The first conductive adhesion layer 10, the second conductive adhesion layer 20, and the seed layer 30 may be provided so as to be in direct contact with each other, or may be formed via another intermediate layer (not shown). good too. Also, the conductive layers 61, 62, and 65 are used when referring to those positioned on the first surface 101, the second surface 102, and the side wall of the through hole 90, respectively. Sometimes referred to as layer 60 .

Insulating layers 71 , 72 , and 75 are formed on the first surface 101 , the second surface 102 , and the sidewalls of the through hole 90 according to the material of the substrate 100 . Further, on the insulating layer 75, the first conductive adhesion layer 15 is formed on a part of the side wall of the through hole on the first surface side. A second conductive adhesion layer 25 is formed on a part of the side wall of the through hole on the second surface side. The first conductive adhesion layer 15 and the second conductive adhesion layer 25 are separated near the center of the through-hole in the illustrated example. Here, in FIG. 13, the end portions of the first conductive adhesion layer 15 and the second conductive adhesion layer 25 are clearly defined, but the end portions of the first conductive adhesion layer 15 and the second conductive adhesion layer 25 are clearly defined. Instead, for example, a shape in which the film thickness is gradually reduced may be used.

The first conductive adhesion layer 15 and the second conductive adhesion layer 25 separated near the center of the through-hole are electrically connected by a seed layer 35 formed thereon. The seed layer 35 consists of the first conductive adhesion layer 15 , the second conductive adhesion layer 25 , and the insulating layer 75 on the side wall of the through hole exposed from the first conductive adhesion layer 15 and the second conductive adhesion layer 25 . It is formed in contact with a part. Furthermore, a conductive layer 65 is formed on the seed layer 35 . The conductive layer 65 electrically connects the first surface 101 and the second surface 102 of the substrate 100 . Conductive layers 61 and 62 may serve as wiring, lands, electrodes, and the like. The rest of the through hole 90 (inside the conductive layer 65) is filled with an insulating filling member 85. As shown in FIG. The insulating filling member 85 can typically be made of an organic insulating material.

As shown in FIG. 13 , an interlayer insulating layer 81 is formed on the first surface 101 of the substrate 100 and an interlayer insulating layer 82 is formed on the second surface 102 of the substrate 100 . Two or more of the interlayer insulating layers 81 and 82 and the insulating filling member 85 may be made of the same material, or each of them may be made of different materials. In the following description, the interlayer insulating layers 81 and 82 may be referred to as an interlayer insulating layer 80 when they are not distinguished from each other. In this example, the interlayer insulating layer 80 is formed directly on the first surface 101 and the second surface 102 of the substrate 100, but another structure (wiring, transistor, capacitor, coil, etc.) is formed between them. may be included. Although a structure having one conductive layer 61, 62 and one interlayer insulating layer 80 is shown, the present invention is not limited to this, and a structure in which two or more layers are laminated may be used.

The interlayer insulating layer 80 can be composed of an organic insulating material, an inorganic insulating material, or the like. Alternatively, an organic insulating material and an inorganic insulating material may be laminated. The opening 111 is formed on the first surface 101 side of the substrate 100 , and the opening 112 is formed on the second surface 102 side of the substrate 100 . When the openings 111 and 112 are not distinguished from each other, they may be referred to as an opening 110 .

[Process Flow of Through Silicon Via Substrate 1]
FIG. 2 is a flow chart explaining a method for manufacturing a through electrode substrate according to the first embodiment of the present invention. A method for manufacturing a through electrode substrate includes a step of forming through holes 90 penetrating through a first surface 101 of a substrate 100 and a second surface 102 opposite to the first surface 101 (step S201), forming the first conductive adhesion layer 10 from the side (step S202); forming the second conductive adhesion layer 20 from the second surface 102 side (step S203); A step of forming the seed layer 30 in contact with the second conductive adhesion layer 20 and in contact with the side wall of the through-hole 90 exposed from the first conductive adhesion layer 10 and the second conductive adhesion layer 20 (step S204 ), forming a conductive layer 60 on the seed layer 30 (step S205), and etching the first conductive adhesion layer, the second conductive adhesion layer, the seed layer and the conductive layer to form a desired pattern. (Step S206). Hereinafter, each step will be described in order with reference to the drawings. It should be noted that this method for manufacturing a through electrode substrate does not prevent other steps from being included between each step.

[Manufacturing method of through electrode substrate 1]
First, step S201 shown in FIG. 2 will be described with reference to FIGS. FIG. 3 is a schematic diagram showing a cross section of a substrate provided with through holes in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. First, the substrate 100 is formed with a through hole 90 penetrating through the first surface 101 and the second surface 102 .

In this example, substrate 100 is a silicon substrate. The substrate 100 may be made of a silicon compound such as silicon carbide, a semiconductor such as gallium arsenide, quartz, glass, sapphire, or the like, or a laminate thereof. The thickness of the substrate 100 is not particularly limited, but is, for example, 100 μm to 800 μm.

The through-holes 90 are formed by forming a mask (not shown) on one surface (for example, the first surface 101) of the substrate 100 and performing RIE (Reactive Ion Etching), DRIE (Deep RIE). It can be formed by dry etching such as ion etching, sandblasting, laser processing, or the like. The through-hole 90 is formed by forming a bottomed hole that does not penetrate in the thickness direction in the substrate, and then polishing the surface opposite to the one surface (for example, the second surface 102) to open it. good too. The size of the opening of the through hole 90 is not particularly limited, and can be, for example, 10 μm to 100 μm. Further, the shape of the through-hole 90 is not limited and is typically circular, but may be rectangular or polygonal other than circular. For example, the aspect ratio of the through hole 90 is 5 or more, preferably 8 or more, although it depends on the use of the through electrode substrate 1 . The aspect ratio refers to a value obtained by dividing the value of the depth of the through-hole 90 by the size of the opening of the through-hole. One or more such through holes 90 are arranged in the substrate 100 .

In each figure, the through-hole 90 has a straight shape in the thickness direction of the through-electrode substrate 1, but is not limited to this. For example, as shown in FIG. It may be tapered larger than the side openings. Moreover, it is not limited to a tapered shape, and may be a concave shape in which the central portion of the through hole 90 is concave as shown in FIG. 16, or a convex shape in which the central portion of the through hole 90 is convex as shown in FIG. .

FIG. 4 is a schematic diagram showing a cross section of a substrate on which an insulating layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. As shown in FIG. 4, an insulating layer 70 (insulating layers 71, 72, 75) is formed on the substrate 100 shown in FIG. The insulating layer 70 should be formed at least on the sidewalls of the through holes 90 .

The insulating layer 70 is, for example, a single layer film made of one material selected from inorganic insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride, and organic insulating materials such as polyimide and benzocyclobutene, or two layers. A laminated film or the like made of the above materials may be used. The insulating layer 70 is formed by a CVD method (plasma CVD method, thermal CVD method, etc.), a PVD method (evaporation method, sputtering method, etc.), a thermal oxidation method, a spray coating method, or the like. The thickness of the insulating layer 70 is not particularly limited as long as the desired insulating properties can be obtained, but can be, for example, 0.5 μm to 5 μm. Another structure may exist between the first surface 101 of the substrate 100 and the insulating layer 71 . If the substrate is an insulating substrate such as quartz, glass, or sapphire, the presence of the insulating layer 70 is optional.

Next, step S202 shown in FIG. 2 will be described using FIG. FIG. 5 is a schematic diagram showing a cross section of a substrate on which a first conductive adhesion layer is formed from one side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. A first conductive adhesion layer 10 is formed on the substrate 100 shown in FIG. The first conductive adhesive layer 10 is formed on the insulating layer 70 from the first surface 101 side. The first conductive adhesion layer 10 is formed by a sputtering method.

The sputtering method is a film forming method in which the film forming atoms reach the substrate in a state of having high energy. to be introduced. A deposition source cluster sputtered by Ar gas ions has a high probability of colliding with Ar atoms during flight, changes the direction of travel, and reduces the directivity of the cluster. As a result, when a film is formed from the first surface side in a through-hole having a high aspect ratio exceeding 5, as shown in FIG. The position of the end of the conductive adhesion layer 15 is half or less of the depth of the through-hole on the basis of the first surface 101 side.

In the present invention, the film-forming atoms that reach the substrate react with the underlying film with surplus energy by the sputtering method in which the film-forming atoms reach the substrate in a state of having high energy, so good adhesion can be obtained. . When a film is formed by a sputtering method, a mixing layer in which the underlying atoms and the film forming atoms are mixed is formed at the interface between the underlying film and the sputtering film, and this mixing layer provides good adhesion between the underlying film and the sputtering film. is obtained.

Next, step S203 shown in FIG. 2 will be described using FIG. FIG. 6 is a schematic diagram showing a cross section of a substrate on which a second conductive adhesion layer is formed from the other side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. A second conductive adhesion layer 20 (second conductive adhesion layers 22 and 25) is formed on the substrate 100 shown in FIG. The second conductive adhesive layer 20 is formed on the insulating layer 70 from the second surface 102 opposite to the first surface 101 . The second conductive adhesion layer 20 is formed by sputtering in the same manner as the first conductive adhesion layer 10 . As a result, as shown in FIG. 6, the position of the end of the second conductive adhesion layer 25 formed on the side wall of the through hole is less than half the depth of the through hole with respect to the second surface 102 side. The first conductive adhesion layer 15 and the second conductive adhesion layer 25 are separated from each other on the sidewall of the through hole. At this time, the insulating layer 75 on the side wall of the through hole is exposed near the center between the first surface 101 and the second surface 102 in the depth direction of the through hole.

The first conductive adhesion layer 15 and the second conductive adhesion layer 25 have good adhesion to the underlying insulating layer 75, and are, for example, titanium (Ti), chromium (Cr), aluminum (Al), compounds thereof, or These alloys and the like can be used. The thicknesses of the first conductive adhesion layer 15 and the second conductive adhesion layer 25 are not particularly limited, but can be, for example, 50 nm to 400 nm. The first conductive adhesion layer 15 and the second conductive adhesion layer 25 may be made of the same material, or may be made of different materials.

In the first embodiment, an example in which a film with high adhesion is formed by a sputtering method has been described, but the present invention is not limited to this. For example, good adhesion can be obtained by using a material that utilizes reactivity with the underlying film. For example, when the base film is silicon oxide, good adhesion can be obtained by using a material whose enthalpy of oxide formation is lower than that of silicon. For example, when titanium, whose enthalpy of oxide formation is lower than that of silicon, is deposited on silicon oxide, oxygen atoms near the interface between silicon oxide and titanium tend to form titanium oxide, which is more stable than silicon oxide. Uses the energy of the film to bond with titanium. In other words, since the interface between silicon oxide and titanium is chemically bonded, good adhesion can be obtained. In other words, good adhesion can be obtained by using, as a material for the conductive layer, a material in which the oxide or nitride of the conductive layer has a lower enthalpy of formation than the oxide or nitride of the underlying film. It is possible.

Next, step S204 shown in FIG. 2 will be described with reference to FIGS. FIG. 7 is a schematic diagram showing a cross section of a substrate on which a seed layer is formed from one side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. The seed layer 30 (seed layers 31 and 35) is formed by oblique vapor deposition. A detailed method of oblique vapor deposition will be described later (see FIGS. 19 and 20).

FIG. 8 is a schematic diagram showing a cross section of a substrate on which a seed layer is formed from the other side surface in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. Also here, a seed layer 30 (seed layers 32 and 35) is formed by oblique vapor deposition from the second surface side of the substrate in the same manner as in FIG. Subsequently, by performing oblique vapor deposition also from the second surface side, a seed layer 35 having a substantially uniform thickness in the depth direction of the through-hole is formed inside the through-hole. Here, in the first embodiment, an example in which the seed layer 30 is formed by oblique vapor deposition has been described, but the present invention is not limited to this, and electroless plating, for example, can also be used. As a result, most of the seed layer 30 formed by a method other than the sputtering method is formed on the first conductive adhesion layer 15 and the second conductive adhesion layer 25 on the sidewalls of the through hole 90, thereby allowing the lower layers to be deposited. The adhesion of is improved. Here, the seed layer 35 is formed so as to climb over the stepped portions of the first conductive adhesion layer 15 and the second conductive adhesion layer 25 . It is considered that the contact between the seed layer 35 and the first conductive adhesion layer 15 or the second conductive adhesion layer 25 at the stepped portion provides an anchoring effect, thereby suppressing peeling of the seed layer 30 .

Here, the seed layer 30 functions as a layer for feeding electricity in electroplating when forming a conductive layer in a later step. The seed layer 30 is preferably made of the same material as the conductive layer, such as copper (Cu), silver (Ag), and gold (Au). The film thickness of the seed layer 30 is not particularly limited, but is preferably in the range of 0.1 μm or more and 1.0 μm or less, for example. Preferably, the thickness is 600 nm or more and 900 nm or less. With such a range, the film thickness of the conductive layer formed in the through hole 90 can be uniformly controlled.

Next, step S205 shown in FIG. 2 will be described using FIG. FIG. 9 is a schematic diagram showing a cross section of a substrate on which a conductive layer 60 is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the invention. Although not shown, in order to obtain the structure shown in FIG. 9, first, a film-like resist called a photosensitive dry film resist is formed on both surfaces of the substrate 100 on which the seed layer 30 is formed, and a conductive layer is formed by photolithography. A mask is formed in which a region to be formed is opened. Next, with a mask applied, power is supplied to the seed layer 30 to perform electroplating, thereby forming the conductive layer 60 (conductive layers 61, 62, 65) as shown in FIG. As the material of the conductive layer, for example, Cu, Ag, Au, or the like can be used. Among them, Cu is preferable because of its low material cost. By forming a thin film along the side wall of the through hole 90, production efficiency is improved. Although there is no particular limitation on the film thickness of the conductive layer 60, the film thickness may be in the range of 1 μm to 20 μm, for example. The thickness is preferably 3 μm or more and 15 μm or less. By setting it as such a range, a through electrode with good conductivity can be obtained.

The formation of the conductive layer 60 on the side wall of the through-hole 90 and the first or second surface of the substrate may be performed in separate processes, but by performing the above in an electrolytic plating process capable of forming the above at the same time, the production efficiency is improved. improves. In addition, since the conductive layer is formed on the side wall of the through hole 90 and the first or second surface of the substrate in the electroplating process, the film thickness of the conductive layer at each location is approximately the same value. After that, the mask is removed from the substrate 100 . Through the above steps, the structure shown in FIG. 9 can be obtained.

Next, step S206 shown in FIG. 2 will be described using FIG. FIG. 10 is a schematic diagram showing a cross section of a substrate having a patterned conductive layer in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. The structure shown in FIG. 10 is obtained by etching the structure shown in FIG. 9 from the first surface side and the second surface side. Dry etching may be used for the etching, or wet etching may be used. Dry etching can etch the first conductive adhesion layer, the second conductive adhesion layer, and the seed layer all at once, which has the advantage of shortening the process. Since etching is hardly performed, the shape change of the conductive layer 65 can be suppressed. In addition, since wet etching can etch the first surface and the second surface at the same time, it has the advantage of shortening the process.

In the first embodiment, the method of forming the conductive layer after patterning has been described, but when the conductive layer 60 is not used, the patterning may be performed after the seed layer 30 is formed.

FIG. 11 is a schematic diagram showing a cross section of a substrate on which a first photosensitive resin layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the invention. A first photosensitive resin layer 89 is formed on the second surface 102 side of the substrate 100 shown in FIG. The first photosensitive resin layer 89 is formed, for example, by using a negative dry film resist and using a laminating device or the like. A portion of the first photosensitive resin layer 89 is partially introduced into the through hole 90 . The dry film resist to be used is not limited to the negative type, and may be of the positive type.

At this time, the opening of the through hole 90 on the second surface 102 side is closed by the first photosensitive resin layer 89 . Note that the first photosensitive resin layer 89 may be formed using a material other than dry film resist as long as it is formed so as to close the opening of the through hole 90 on the second surface 102 side. A high-viscosity (for example, 20 cp or more) liquid resist may be used.

FIG. 12 is a schematic diagram showing a cross section of a substrate on which a second photosensitive resin layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the invention. As shown in FIG. 12, a second photosensitive resin layer 88 is formed on the first surface 101 side of the substrate 100 . The second photosensitive resin layer 88 is formed, for example, by using a negative dry film resist and using a laminating device or the like. The dry film resist to be used is not limited to the negative type, and may be of the positive type.

At this time, the surrounding environment of the substrate 100 is reduced (lower than the atmospheric pressure) for lamination. Thereby, the dry film resist of the second photosensitive resin layer 88 is introduced into the through holes 90 and comes into contact with the first photosensitive resin layer 89 . As a result, the through hole 90 is filled with the photosensitive resin layer, that is, the insulating filling member 85 is formed. In the state shown in FIG. 10, the portion remaining as a space in the through-hole 90 (the portion surrounded by the conductive layer 65) is filled with the first photosensitive resin layer 89 and the second photosensitive resin layer 88. be done. Since the lamination of the second photosensitive resin layer 88 is performed while the gas inside the through-holes 90 is exhausted under reduced pressure, the occurrence of voids or the like inside the through-holes 90 can be suppressed. In this specification, the term "filling" is not limited to the case of completely eliminating the space (voids, etc.), and does not exclude the case where a small amount of space remains inside the through-hole 90 .

When forming the second photosensitive resin layer 88, it is desirable to keep the pressure of the surrounding environment of the substrate 100 as close to vacuum as possible when laminating the dry film resist. This makes it easier to introduce the dry film resist into the through hole 90 . In addition to the above method, the photosensitive resin layer may be formed on the first surface and the second surface after filling the through hole 90 with the insulating material.

FIG. 13 is a schematic diagram showing a cross section of a substrate on which first and second photosensitive resin layers are patterned in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. Patterning by photolithography is performed on the first photosensitive resin layer 89 and the second photosensitive resin layer 88 formed on the substrate 100 of FIG. Thereby, as shown in FIG. 13, an opening 111 reaching the conductive layer 61 and an opening 112 reaching the conductive layer 62 are formed. After that, the photosensitive resin layer may be baked. FIG. 13 shows the interlayer insulating layer 80 (interlayer insulating layers 81 and 82) and the insulating filling member 85 thus obtained from the photosensitive resin layer. The thickness of the interlayer insulating layer 80 on the first surface 101 and the second surface 102 of the substrate 100 is, for example, 10 μm to 100 μm, but may be thinner or thicker.

The through electrode substrate 1 manufactured as described above includes conductive layers (the first conductive adhesion layer 15, the second conductive adhesion layer 25, the seed layer 35, the conductive layers) formed along the sidewalls of the through hole 90. 65) can electrically connect the first surface 101 side and the second surface 102 side of the substrate 100 . In addition, by filling the inside of the through hole 90 with the insulating resin as described above, the manufacturing process can be shortened compared to filling the inside of the through hole 90 with a metal material by the electroplating method. It can also be suppressed.

FIG. 14 is a schematic diagram showing a cross section of a substrate on which a wiring layer is formed in the method for manufacturing a through electrode substrate according to the first embodiment of the invention. Wiring layers 121 and 122 may be formed as shown in FIG. 14 using the through electrode substrate 1 manufactured as shown in FIG. A wiring layer is formed on the through electrode substrate 1 shown in FIG. 13, and the wiring layers 121 and 122 are obtained by patterning the wiring layer by photolithography. Note that such wiring layers may be multi-layered via an interlayer insulating film.

The wiring layers 121 and 122 thus obtained (usually the outermost wiring layers when multilayered) are used as connection terminals when connecting to other through electrode substrates 1 and the like.

[Method for Forming Seed Layer 30]
Here, a method for forming the seed layer 30 shown in FIGS. 7 and 8 will be described in detail. In the step of forming the seed layer 30, it is necessary to form a conductive layer inside a through-hole having a high aspect ratio exceeding 5, so a film formation method with good film throwing power is required. be. As a method for good film throwing power, for example, a method in which a film grows isotropically with respect to the growth surface, such as electroless plating, or a method such as oblique vapor deposition, which is highly anisotropic, is used to separate the film source from the substrate. A method of forming a film with good coverage can be mentioned. Here, as an example, a film forming method by oblique vapor deposition will be described in detail. Note that the oblique vapor deposition is vapor deposition set so that the vapor deposition material flying from the vapor deposition source reaches the surface of the substrate while being inclined with respect to the normal to the surface of the substrate on which the film is to be formed.

FIG. 18 is a schematic diagram of a film forming apparatus using oblique vapor deposition in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. The film forming apparatus shown in FIG. 18 comprises a vacuum chamber 150 that achieves high vacuum, a turbomolecular pump (TMP) 220 and a gate valve 222 for vapor deposition. The vacuum chamber 150 has a holder 141 for fixing the substrate in a state in which an angle 132 formed by the lines parallel to the flight direction of the vapor deposition material and the perpendicular 130 of the substrate is tilted at a constant angle 132 on the plane including the perpendicular 130 to the substrate. A rotating support column 140 that rotates a holder 141 while maintaining a constant angle 132, a crucible 210 that holds an evaporation source 212, and an electron gun 200 that generates an electron beam 201 that evaporates the evaporation source 212 are provided.

During vapor deposition, it is desirable to use TMP in a high vacuum state of, for example, 10 ⁻³ to 10 ⁻⁶ Pa in order to improve the straightness of the evaporated vapor deposition material 214 . When vapor deposition is performed in such a high-vacuum state, the collision probability of the evaporated vapor deposition material 214 with gas molecules in the chamber is reduced, so that the change in traveling direction due to scattering is reduced. As a result, the vapor deposition material 214 reaches the substrate with a very high straightness, so that sufficient coverage can be obtained even for through-holes with a high aspect ratio, for example, an aspect ratio exceeding 5. . Further, by performing vapor deposition while rotating the rotary support column 140 with the holder 141 tilted, it is possible to form a uniform film in the circumferential direction of the through-hole.

FIG. 19 is a schematic diagram showing a cross-sectional view of a through electrode substrate on which a conductive layer is formed by oblique vapor deposition in the method for manufacturing a through electrode substrate according to the first embodiment of the present invention. The deposition material 214 evaporated by the electron beam 201 is incident on the substrate at a constant angle 132 with respect to the normal 130 of the substrate. The angle 132 may be determined according to the aspect ratio of the through-hole in which the deposited film is to be formed. The angle should be such that it reaches Preferably, for example, the angle should be such that it reaches the conductive layer end 29 inside the through-hole formed on the opposite side of the vapor deposition surface. Specifically, when oblique vapor deposition is performed on a through-hole having an aspect ratio of 5, the angle formed by the perpendicular to the first surface or the second surface of the substrate is 5° or more and 20° or less. A vapor deposition film can be formed with good performance.

<Second embodiment>
In the first embodiment, only one layer of the first conductive adhesion layer 10 or the second conductive adhesion layer 20 is sandwiched between the insulating layer 70 on the side wall of the through hole and the seed layer 30 . In the second embodiment, a structure in which a plurality of layers are sandwiched between the insulating layer 70 on the side wall of the through hole and the seed layer 30 will be described.

FIG. 20 is a schematic diagram showing a cross section of a substrate on which a conductive layer is formed in a method for manufacturing a through electrode substrate according to the second embodiment of the invention. 13 is that a third conductive adhesion layer 40 (third conductive adhesion layers 41, 42, 45) is formed between the first conductive adhesion layer 10 and the seed layer 30; A fourth conductive adhesion layer 50 (fourth conductive adhesion layers 51 , 52 , 55 ) is formed between the second conductive adhesion layer 20 and the seed layer 30 .

The third conductive adhesion layer 40 and the fourth conductive adhesion layer 50 are preferably made of a material having good adhesion to the seed layer 30 , preferably the same material as the seed layer 30 . In this case, it can be considered that the third conductive adhesion layer 40 and the fourth conductive adhesion layer 50 also serve as part of the seed layer. Moreover, it is desirable that the third conductive adhesion layer 40 has good adhesion with the first conductive adhesion layer 10 and the fourth conductive adhesion layer 50 has good adhesion with the second conductive adhesion layer 20 . In the second embodiment, since the third conductive adhesion layer 40 and the fourth conductive adhesion layer 50 are formed by sputtering, at the interface between the first conductive adhesion layer 10 and the third conductive adhesion layer 40, Good adhesion is obtained. Similarly, good adhesion can be obtained at the interface between the second conductive adhesion layer 20 and the fourth conductive adhesion layer 50 . This is the mixing layer of the layer in contact with the interface between the first conductive adhesion layer 10 and the third conductive adhesion layer 40 and the interface between the second conductive adhesion layer 20 and the fourth conductive adhesion layer 50, respectively. is thought to be formed. Furthermore, when the third conductive adhesion layer 40, the fourth conductive adhesion layer 50, and the seed layer 30 are made of the same material, good adhesion can be obtained at their interfaces as well.

<Third Embodiment>
In the third embodiment, a semiconductor device manufactured using the through electrode substrate 1 in the first or second embodiment will be described.

FIG. 21 is a diagram showing a semiconductor device according to a third embodiment of the invention. In the semiconductor device 1000 , three through electrode substrates 300 ( 310 , 320 , 330 ) are laminated and connected to the LSI substrate 400 . The through electrode substrate 310 is formed with a semiconductor element such as a DRAM, for example, and has connection terminals 511 and 512 formed of wiring layers 121 and 122 and the like. One or more of these through electrode substrates 300 may be through electrode substrates made of a substrate formed of glass, sapphire, or the like. The connection terminals 512 are connected to the connection terminals 500 of the LSI substrate 400 by bumps 610 . The connection terminals 511 are connected to connection terminals 522 of the through electrode substrate 320 by bumps 620 . The connection terminals 521 of the through electrode substrate 320 and the connection terminals 532 of the through electrode substrate 330 are also connected by bumps 630 . The bumps 600 (610, 620, 630) use metal such as indium, copper, gold, or the like.

When the through electrode substrates 1 are laminated, the number of layers is not limited to three, and may be two or four or more. Moreover, the connection between the through electrode substrate 1 and another substrate is not limited to the bump, and other bonding techniques such as eutectic bonding may be used. Alternatively, the through electrode substrate 1 and another substrate may be bonded by applying and baking polyimide, epoxy resin, or the like.

FIG. 22 is a diagram showing another example of the semiconductor device according to the third embodiment of the invention. A semiconductor device 1000 shown in FIG. 22 has semiconductor chips (LSI chips) 410 and 420 such as a MEMS device, a CPU and a memory, and a through electrode substrate 300 stacked and connected to the LSI substrate 400 .

Through electrode substrate 300 is arranged between semiconductor chip 410 and semiconductor chip 420 and connected by bumps 640 and 650 . A semiconductor chip 410 is mounted on an LSI substrate 400 , and the LSI substrate 400 and semiconductor chip 420 are connected by wires 700 . In this example, the through electrode substrate 300 is used as an interposer for stacking a plurality of semiconductor chips and mounting them three-dimensionally. By stacking a plurality of semiconductor chips with different functions, a multifunctional semiconductor device is manufactured. can do. For example, by using the semiconductor chip 410 as a 3-axis acceleration sensor and the semiconductor chip 420 as a 2-axis magnetic sensor, a semiconductor device realizing a 5-axis motion sensor in one module can be manufactured.

When the semiconductor chip is a sensor formed of a MEMS device, the sensing result may be output as an analog signal. In this case, a low-pass filter, an amplifier, etc. may also be formed on the semiconductor chip or through electrode substrate 300 .

FIG. 23 is a diagram showing another example of the semiconductor device according to the third embodiment of the invention. Although the above two examples (FIGS. 21 and 22) are three-dimensional implementations, this example is an example applied to both two-dimensional and three-dimensional implementations. In the example shown in FIG. 23, an LSI substrate 400 has six through electrode substrates 300 (310 to 360) laminated and connected. However, not only are all the through electrode substrates 300 stacked and arranged, but they are also arranged side by side in the substrate in-plane direction. One or more of these through electrode substrates 300 (310 to 360) may be through electrode substrates made of a substrate formed of glass, sapphire, or the like.

In the example of FIG. 23 , through electrode substrates 310 and 350 are connected on the LSI substrate 400 , through electrode substrates 320 and 340 are connected on the through electrode substrate 310 , and through electrode substrate 330 is connected on the through electrode substrate 320 . , a through electrode substrate 360 is connected on the through electrode substrate 350 . As in the example shown in FIG. 22, even if the through electrode substrate 300 is used as an interposer for connecting a plurality of semiconductor chips, both two-dimensional and three-dimensional mounting is possible. For example, the through electrode substrates 330, 340, 360, etc. may be replaced with semiconductor chips.

The semiconductor device 1000 manufactured as described above can be used in various applications such as mobile terminals (mobile phones, smart phones, notebook personal computers, etc.), information processing devices (desktop personal computers, servers, car navigation systems, etc.), home appliances, and the like. Installed in electrical equipment.

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited only to these examples.

Example 1 will be described based on FIG. 20 of the second embodiment. First, a silicon substrate having a thickness of 400 μm was prepared as the substrate 100 . Next, a resist pattern is formed on one surface of the silicon substrate (here, the first surface 101) by photolithography, and the silicon substrate is etched in the thickness direction by DRIE through the resist pattern to form a large number of φ50 μm through holes. did. The aspect ratio of the through holes was 8.

After forming through-holes and removing the resist pattern, a silicon oxide film was formed on the surface of the silicon substrate and on the sidewalls of the through-holes by thermal oxidation. Here, thermal oxidation was carried out at 1050° C. in an oxygen atmosphere to form a silicon oxide film of 500 nm.

Next, from the first surface 101 side of the silicon substrate, a first conductive adhesion layer 10 was formed with a thickness of 100 nm of Ti, which has good adhesion with the silicon oxide film formed on the silicon substrate, by a sputtering method. Subsequently, Ti was formed to a thickness of 100 nm as the second conductive adhesion layer 20 from the second surface 102 side of the silicon substrate by sputtering in the same manner as described above. Here, the sputtering method was performed under the following conditions by the DC magnetron sputtering method.
・Distance between target and substrate = 100mm
・Argon gas flow rate = 30 sccm
・Chamber pressure = 0.5 Pa
・Power = 3 kW
・Deposition temperature = room temperature

Next, from the first surface 101 side of the silicon substrate, 100 nm of Cu was formed as the third conductive adhesive layer 40 by a sputtering method. Subsequently, from the second surface 102 side of the silicon substrate, as the fourth conductive adhesion layer 50, a Cu film was formed with a thickness of 100 nm by sputtering in the same manner as described above to form a sputter seed layer. Here, the sputtering method was performed under the following conditions by the DC magnetron sputtering method.
・Distance between target and substrate = 100mm
・Argon gas flow rate = 30 sccm
・Chamber pressure = 0.3 Pa
・Power = 5 kW
・Deposition temperature = room temperature

Next, from the side of the first surface 101 of the silicon substrate, Cu was formed as the seed layer 30 on the Cu formed by the sputtering method with a thickness of 800 nm by oblique vapor deposition to form a vapor deposition seed layer. Furthermore, from the second surface 102 side of the silicon substrate, a Cu film having a thickness of 800 nm was formed by oblique vapor deposition in the same manner. At this time, the inclination of the silicon substrate was adjusted so that the angle formed by a line parallel to the flight direction of the vapor deposition material and the perpendicular to the silicon substrate was 8°. Moreover, the vapor deposition method was performed under the following conditions.
・Vapor deposition source - substrate distance = 100 mm
・Vacuum ultimate pressure = 5 × 10 ^-4 Pa
・The angle between the line parallel to the flight direction of the vapor deposition material and the perpendicular to the substrate = 8°

Next, a plating resist pattern was formed on both sides of the silicon substrate so as to cover regions where formation of a conductive film should be avoided in electrolytic plating, which will be described later. Then, by electroplating, a Cu film was formed with a thickness of 10 μm on the portion exposed from the resist pattern for plating to form a conductive film.

Thereafter, after removing the plating resist pattern, unnecessary vapor deposition seed and sputter seed layers existing on both sides of the silicon substrate were sequentially removed. As a result, the through electrode substrate shown in FIG. 20 was obtained.

A continuity test was conducted on the through electrode substrate obtained as described above, and it was confirmed that the chip including 1024 through electrodes was properly secured in continuity.

As described above, according to Example 1, it is possible to obtain a through electrode substrate having a through hole with a high aspect ratio, in which the conductive layer in the through hole has high adhesiveness.

1: through electrode substrates 10, 11, 15: first conductive adhesion layers 20, 22, 25, 29: second conductive adhesion layers 30, 31, 32, 35: seed layers 40, 41, 42, 45: second 3 conductive adhesive layers 50, 51, 52, 55: fourth conductive adhesive layers 60, 61, 62, 65: conductive layers 70, 71, 72, 85: insulating layer 79: edges 80, 81, 82: interlayer Insulating layer 85: insulating filling member 88: second photosensitive resin layer 89: first photosensitive resin layer 90: through hole 100: substrate 101: first surface 102: second surface 110, 111, 112: opening Sections 121 and 122: Wiring layer 130: Perpendicular line 132: Angle 140 formed between the perpendicular line of the substrate and the vapor deposition direction: Rotating support column 141: Holder 150: Vacuum chamber 200: Electron gun 201: Electron beam 210: Crucible 212: Deposition source 214 : vapor deposition material 222: gate valves 300, 310, 320, 330, 340, 350, 360: through electrode substrate 400: LSI substrates 410, 420: semiconductor chips 500, 511, 512, 521, 522, 531: connection terminals 600, 610, 620, 630, 640, 650: bump 700: wire 1000: semiconductor device

Claims (6)

a substrate having a through hole extending through the first surface and the second surface;
a first conductive layer provided on a portion of the first surface side in a region sandwiched between sidewalls of the through hole;
a second conductive layer spaced apart from the first conductive layer in a portion of the second surface side in a region sandwiched between sidewalls of the through hole;
a third conductive layer connecting the first conductive layer and the second conductive layer;
provided between the first conductive layer and the sidewall of the through hole, between the second conductive layer and the sidewall of the through hole, and between the third conductive layer and the sidewall of the through hole; and an insulating layer containing any one of silicon, silicon oxynitride, and an organic insulating material. 2. The through electrode substrate according to claim 1, wherein said third conductive layer is in contact with said insulating layer between said first conductive layer and said second conductive layer. 3. The through electrode substrate according to claim 1, wherein said first conductive layer and said second conductive layer are in contact with said insulating layer. 4. The third conductive layer according to claim 1, wherein said third conductive layer is provided continuously between said first conductive layer and said second conductive layer and connects said first conductive layer and said second conductive layer. 1. The through electrode substrate according to 1. The through electrode substrate according to any one of claims 1 to 4, wherein the substrate is a semiconductor substrate. 5. The insulating material according to any one of claims 1 to 4, further comprising an insulating material arranged continuously from the first surface side to the second surface side inside the through hole rather than the third conductive layer. through electrode substrate.

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