JP2009267098A - Semiconductor apparatus and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a semiconductor apparatus and a method of manufacturing the same for forming a fine penetrating wiring in a penetrating part having a high aspect ratio using a dry process. <P>SOLUTION: When a probe for supplying a current is contacted to a wiring 13 to flow a large current in a direction of a penetrating part 11e, electromigration which causes a metallic element of the wiring 13 to move in the direction of current arises. Since a region except an opening of the penetrating part 11e of the wiring 13 is put under restraint by a substrate surface 11d of an SOI substrate 11, the metallic element is collected to the opening of the penetrating part 11e that is not put under restraint. The collected metallic element is arranged in a fine-line shape by self-organization, and a metallic fine line 14 is grown toward an electrode 23 in the penetrating part 11e to connect the wiring 13 and the electrode 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device provided with a through wiring that electrically connects an element and a circuit, and a manufacturing method thereof.

In recent years, electronic devices are increasingly required to be miniaturized, and there is an increasing demand for higher integration of semiconductor devices. Therefore, if the element and the circuit board are connected with a wire, a space for the wire is required, and it is difficult to reduce the size of the semiconductor device. For example, Patent Document 1 discloses an element and a circuit. A semiconductor device including a through wiring that is electrically connected is disclosed.
JP 2007-180204 A

  However, when the through wiring is formed by a wet process such as plating, it is difficult to form a fine through wiring in the through hole having a high aspect ratio.

  Therefore, an object of the present invention is to realize a semiconductor device capable of forming a fine through wiring in a through portion having a high aspect ratio by using a dry process, and a manufacturing method thereof.

  In order to achieve the above object, according to a first aspect of the present invention, in the first aspect of the present invention, the first element and the first metal wiring electrically connected to the first element are provided on the substrate surface. A first substrate, a second substrate having a second element on the substrate surface and a second metal wiring electrically connected to the second element, and a back surface of the first substrate and the second substrate A semiconductor device formed by being bonded to a second substrate surface, wherein the first substrate is provided with a penetrating portion penetratingly formed in a thickness direction, and the first metal wiring and the first substrate At least a portion of each of the two metal wirings faces the opening of the penetrating portion, and the first metal wiring and the second metal wiring pass an electric current through the first metal wiring to perform electromigration. By generating the first metal wiring, the thickness inside the through portion It is electrically connected by thin metal wires formed by growing the direction, using the technical means of.

  According to the first aspect of the present invention, the first metal wiring formed on the first substrate and the second metal wiring formed on the second substrate cause a current to flow through the first metal wiring. By generating electromigration, the first metal wiring can be electrically connected by a thin metal wire formed by growing in the thickness direction inside the through portion. Thereby, the through wiring for electrically connecting the first element and the second element can be formed in the through part having a high aspect ratio by using a dry process.

  According to a second aspect of the present invention, in the semiconductor device according to the first aspect, a technical means is used in which the first metal wiring is made of Al or an alloy containing Al as a main component.

  As in the second aspect of the invention, the first metal wiring can be formed from Al generally used as the metal wiring or an alloy containing Al as a main component. In addition, it is preferable that the first metal wiring is formed of Al or an alloy containing Al as a main component because the growth rate of the thin metal wire can be increased.

  According to a third aspect of the present invention, in the semiconductor device according to the first or second aspect, the technical means is used in which the thin metal wire is formed so as not to contact the inner side surface of the penetrating portion. .

  As in the third aspect of the invention, in the semiconductor device of the present invention, the fine metal wire can be formed so as not to contact the inner side surface of the penetrating portion. Thereby, it is not necessary to form an insulating film on the inner surface of the penetrating portion.

  According to a fourth aspect of the present invention, in the semiconductor device according to any one of the first to third aspects, a technical means is used in which the first metal wiring is covered with an insulating film. .

  According to the fourth aspect of the present invention, since the first metal wiring is covered with the insulating film, the first metal wiring is restrained by the insulating film when current is passed through the first metal wiring to generate electromigration. Therefore, it is possible to easily grow in the thickness direction from the unconstrained region formed in the opening of the through portion, so that the growth speed of the metal fine wire can be increased and the metal fine wire can be formed in a short time can do.

  According to a fifth aspect of the present invention, in the semiconductor device according to any one of the first to fourth aspects, a plurality of the first metal wiring and the second metal wiring are provided for a plurality of the first metal wiring and the second metal wiring. The technical means that the penetration part is provided and the said metal fine wire is formed in each penetration part is used.

  According to the invention described in claim 5, since the first metal wiring and the second metal wiring can be connected by the plurality of fine metal wires, the reliability of the wiring can be improved.

  According to a sixth aspect of the present invention, in the semiconductor device according to any one of the first to fifth aspects, the first substrate includes an element formation substrate on which the first element is formed. A technical means is used that is an SOI (Silicon on Insulator) substrate laminated on a support substrate through a buried oxide film.

  According to a sixth aspect of the present invention, an SOI (Silicon on Insulator) in which an element formation substrate on which a first element is formed as a first substrate is laminated on a support substrate via a buried oxide film. ) A substrate can be suitably used. For example, as the first element, a sensor part of an acceleration sensor formed by MEMS technology can be formed.

  According to a seventh aspect of the present invention, in the method for manufacturing a semiconductor device, a first substrate including a first element and a first metal wiring electrically connected to the first element on a substrate surface; Preparing a second substrate having a second element and a second metal wiring electrically connected to the second element on the substrate surface, and from the back surface of the first substrate, A step of penetrating the through portion so that the opening faces at least a portion of the first metal wiring; and the other opening of the through portion so as to face at least a portion of the second metal wiring. A step of bonding a second substrate to the first substrate, and passing a current through the first metal wiring to generate electromigration, thereby causing the first metal wiring to have a thickness inside the through portion. Grown in a direction, the first metal wiring and the second metal wiring, Forming a thin metal wires for electrically connecting, with a use of technical means that.

  According to the seventh aspect of the present invention, the first metal wiring formed on the first substrate and the second metal wiring formed on the second substrate cause a current to flow through the first metal wiring. By generating electromigration, the first metal wiring can be electrically connected by a thin metal wire formed by growing in the thickness direction inside the through portion. Thereby, the through wiring for electrically connecting the first element and the second element can be formed in the through part having a high aspect ratio by using a dry process.

  According to an eighth aspect of the present invention, in the semiconductor device manufacturing method according to the seventh aspect, a technical means is used in which the first metal wiring is made of Al or an alloy containing Al as a main component.

  As in the eighth aspect of the invention, the first metal wiring can be formed from Al generally used as the metal wiring or an alloy containing Al as a main component. In addition, it is preferable that the first metal wiring is formed of Al or an alloy containing Al as a main component because the growth rate of the thin metal wire can be increased.

  According to a ninth aspect of the present invention, in the method for manufacturing a semiconductor device according to the seventh or eighth aspect, the technical means that the thin metal wire is formed so as not to contact the inner side surface of the through portion. Use.

  As in the ninth aspect of the invention, in the semiconductor device of the present invention, the fine metal wire can be formed so as not to contact the inner side surface of the through portion. Thereby, it is not necessary to form an insulating film on the inner surface of the penetrating portion.

  According to a tenth aspect of the present invention, in the method for manufacturing a semiconductor device according to any one of the seventh to ninth aspects, the first metal wiring is covered with an insulating film. Use means.

  According to the tenth aspect of the present invention, since the first metal wiring is covered with the insulating film, the first metal wiring is restrained by the insulating film when an electric current is passed through the first metal wiring to generate electromigration. Therefore, it is possible to easily grow in the thickness direction from the unconstrained region formed in the opening of the through portion, so that the growth speed of the metal fine wire can be increased and the metal fine wire can be formed in a short time can do.

  According to an eleventh aspect of the present invention, in the method of manufacturing a semiconductor device according to any one of the seventh to tenth aspects, a plurality of sets of the first metal wiring and the second metal wiring are provided in a plurality. The technical means of forming the through portions and forming the fine metal wires in the respective through portions is used.

  According to the eleventh aspect of the present invention, since the first metal wiring and the second metal wiring can be connected by the plurality of thin metal wires, the reliability of the wiring can be improved.

  According to a twelfth aspect of the present invention, in the method of manufacturing a semiconductor device according to any one of the seventh to eleventh aspects, an element forming substrate on which the first element is formed as the first substrate. However, the technical means of using an SOI (Silicon on Insulator) substrate laminated on a supporting substrate through a buried oxide film is used.

  According to a twelfth aspect of the present invention, an SOI (Silicon on Insulator) in which an element formation substrate on which a first element is formed is laminated on a support substrate via a buried oxide film as a first substrate. ) A substrate can be suitably used. For example, as the first element, a sensor part of an acceleration sensor formed by MEMS technology can be formed.

A semiconductor device and a manufacturing method thereof according to the present invention will be described with reference to the drawings. Here, an acceleration sensor having a sensor portion formed by MEMS technology will be described as an example.
FIG. 1 is an explanatory diagram of the semiconductor device of this embodiment. FIG. 1A is a cross-sectional explanatory view, and FIG. 1B is an enlarged plan explanatory view of wiring as viewed from the element formation substrate side. 2 and 3 are cross-sectional explanatory views showing the manufacturing process of the semiconductor device of this embodiment. FIG. 4 is an explanatory plan view showing a modification example of the shape of the wiring or the through portion.
In each drawing, for the sake of explanation, a part is enlarged and exaggerated.

As shown in FIG. 1A, the semiconductor device 10 formed as an acceleration sensor is electrically connected to the SOI substrate 11 on which the sensor unit 12 is formed, and the sensor unit 12, and is output from the sensor unit 12. A semiconductor substrate 21 provided with an integrated circuit 22 for processing acceleration signals is bonded to the substrate.
In addition, the sensor part 12 consists of a well-known structure, and illustration and description of an internal structure are abbreviate | omitted.

  The SOI substrate 11 is formed by laminating an element formation substrate 11c on a support substrate 11a via a buried oxide film 11b. The sensor unit 12 is formed in a predetermined shape by etching the element formation substrate 11c and the buried oxide film 11b.

  A wiring 13 that is electrically connected to the sensor unit 12 is formed on the substrate surface 11d of the element formation substrate 11c. The wiring 13 is formed by patterning an Al thin film formed by sputtering. When the wiring 13 is formed of Al or an alloy containing Al as a main component, the growth rate of the metal thin wire 14 described later can be increased, which is preferable.

  The SOI substrate 11 is provided with a through portion 11e that is formed to penetrate from the substrate surface 11d toward the back surface 11f. As shown in FIG. 1B, in the vicinity of one end 13b of the wiring 13, the wiring 13 covers the opening of the through-hole 11e.

  The semiconductor substrate 21 includes an integrated circuit 22 that performs arithmetic processing on the acceleration signal output from the sensor unit 12, and an electrode 23 that is electrically connected to the integrated circuit 22, and the SOI substrate 11 on the substrate surface 21a side. Is attached to the back surface 11f.

  A part of the electrode 23 is provided at a position corresponding to the opening on the back surface 11f side of the through portion 11e. The wiring 13 and the electrode 23 are electrically connected by a thin metal wire 14 inserted through the through portion 11e. Here, the fine metal wire 14 is an Al fine wire having a thickness of about 1 μm formed from the wiring 13 by a process described later, and is formed so as not to contact the inner wall of the through-hole 11e.

A method for manufacturing the semiconductor device 10 will be described with reference to FIGS.
First, as shown in FIG. 2A, an SOI substrate 11 is prepared in which a sensor unit 12 of an acceleration sensor formed by a known method and a wiring 13 electrically connected to the sensor unit 12 are formed. To do.

  Next, as shown in FIG. 2B, through portions 11e are formed in the thickness direction from the back surface 11f of the SOI substrate 11 toward the substrate surface 11d by photolithography. Here, the penetration part 11 e is formed so that the wiring 13 covers the opening of the penetration part 11 e in the vicinity of one end of the wiring 13.

  Subsequently, as illustrated in FIG. 3C, the semiconductor substrate 21 including the integrated circuit 22 that performs arithmetic processing on the acceleration signal output from the sensor unit 12, and the electrode 23 that is electrically connected to the integrated circuit 22. Is attached to the back surface 11f of the SOI substrate 11 by bonding or bonding on the substrate surface 21a side. Here, the electrode 23 is arrange | positioned in the position corresponding to the opening of the penetration part 11e.

  Subsequently, as shown in FIG. 3D, a thin metal wire 14 is grown inside the through-hole 11e by flowing a current in a direction from the end 13a of the wiring 13 toward the end 13b (FIG. 1B). And electrically connected to the electrode 23 of the semiconductor substrate 21.

A method for forming the fine metal wire 14 will be described. A current supply probe is brought into contact so that the end 13a side of the wiring 13 becomes an anode and the end 13b side becomes a cathode, and a current flows in the direction of the penetrating portion 11e. As a processing condition, for example, a direct current having a current density of 1 MA / cm ² is passed while the temperature is raised to 250 ° C. The processing conditions are arbitrary as long as the fine metal wires 14 can be grown.

  When such a large current flows through the wiring 13, electromigration occurs in which the metal element of the wiring 13 moves in the direction of the current, but the region other than the opening of the through-hole 11 e is constrained by the substrate surface 11 d of the SOI substrate 11. For this reason, the metal elements are concentrated in the opening of the penetrating portion 11e that is not constrained. Aggregated metal elements are arranged in a thin line by self-organization. Thereby, the thin metal wire 14 is formed in the through portion 11e so as to grow toward the electrode 23.

  The fine metal wire 14 grown in the thickness direction inside the through portion 11 e reaches the electrode 23 and electrically connects the wiring 13 and the electrode 23.

  According to this step, the fine metal wire 14 can be grown and formed so as not to contact the inner side surface of the through-hole 11e. Thereby, it is not necessary to form an insulating film on the inner surface of the penetrating part 11e.

  Subsequent to the above-described steps, heat treatment or energization of the fine metal wires 14 can be performed to diffuse the fine metal wires 14 into the electrode 23 and improve the bonding force between them.

(Example of change)
As shown in FIG. 4A, a shape that reduces the width of the wiring 13 toward the penetrating portion 11e can be employed. Since the current density increases on the penetrating part 11e side, the growth rate of the penetrating electrode 19 can be increased. In addition, since the width of the wiring 13 far from the penetrating portion 11e is formed wide, a metal element necessary for forming the penetrating electrode 19 can be sufficiently supplied.

  As shown in FIG. 4B, a plurality of through portions 11 e may be provided for one wiring 13. According to this, since the wiring 13 of the SOI substrate 11 and the electrode 23 of the semiconductor substrate 21 can be connected by the plurality of through electrodes 19, the reliability of the wiring can be improved.

  In this embodiment, Al is used as a material for forming the wiring 13, but the material is not limited to this. For example, other materials having a high diffusion coefficient such as Cu, Ag, Sn, Ni may be used. .

  In the present embodiment, the semiconductor device 10 includes an SOI substrate 11 on which the sensor unit 12 is formed, and an integrated circuit 22 that is electrically connected to the sensor unit 12 and performs arithmetic processing on the acceleration signal output from the sensor unit 12. Although the semiconductor device formed by bonding with the semiconductor substrate 21 is illustrated, the present invention is not limited to this, and the semiconductor device 21 can be configured by a combination of various substrates and elements.

[Effect of the best form]
(1) According to the semiconductor device 10 and the manufacturing method thereof of the present invention, the wiring 13 formed on the SOI substrate 11 and the electrode 23 formed on the semiconductor substrate 21 cause a current to flow through the wiring 13 and generate electromigration. By doing so, the wiring 13 can be electrically connected by the thin metal wire 14 formed by growing in the thickness direction inside the through portion 11e. Thereby, the through wiring for electrically connecting the sensor unit 12 and the integrated circuit 22 can be formed in the through part 11e having a high aspect ratio by using a dry process.

(2) In the semiconductor device 10, the fine metal wires 14 can be grown and formed so as not to contact the inner side surface of the through-hole 11e. Thereby, it is not necessary to form an insulating film on the inner surface of the penetrating part 11e.

[Other embodiments]
(1) As shown in FIG. 5, an insulating film 15 covering the surface of the wiring 13 may be provided. By covering the surface of the wiring 13 with the insulating film 15, current is passed through the wiring 13 to generate electromigration, so that the wiring 13 is constrained by the insulating film 15. Since the through electrode 19 can be easily grown from the unconstrained region, it can be formed in a short time by increasing the growth rate of the through electrode 19. As the insulating film 15, for example, a silicon dioxide film can be used.

(2) A TEG pattern for confirming whether or not the wire connection between the fine metal wire 14 and the electrode 23 is satisfactorily performed may be formed in the wiring of the electrode 23. Thereby, the semiconductor device 10 can be easily inspected.

[Correspondence between each claim and embodiment]
The SOI substrate 11 is the first substrate according to claim 1, the sensor unit 12 is the first element, the wiring 13 is the first wiring, the semiconductor substrate 21 is the second substrate, and the integrated circuit 22 is the first circuit. The electrode 23 corresponds to the second metal wiring, respectively.

It is explanatory drawing of the semiconductor device of this embodiment. FIG. 1A is a cross-sectional explanatory view, and FIG. 1B is an enlarged plan explanatory view of wiring as viewed from the element formation substrate side. It is sectional explanatory drawing which shows the manufacturing process of the semiconductor device of this embodiment. It is sectional explanatory drawing which shows the manufacturing process of the semiconductor device of this embodiment. It is plane explanatory drawing which shows the example of a change of the shape of wiring or a penetration part. It is sectional explanatory drawing which shows the example of a change of the semiconductor device of this invention.

Explanation of symbols

10 Semiconductor device 11 SOI substrate (first substrate)
11d Substrate surface 11e Penetration part 12 Sensor part (first element)
13 Wiring (first metal wiring)
14 Metal wire 15 Insulating film 21 Semiconductor substrate (second substrate)
21a Substrate surface 22 Integrated circuit (second element)
23 Electrode (second metal wiring)

Claims (12)

A first substrate having a first element on the substrate surface and a first metal wiring electrically connected to the first element; a second element on the substrate surface; And a second substrate having a second metal wiring connected to each other, wherein the second substrate is bonded to the back surface of the first substrate and the second substrate surface.
The first substrate is provided with a penetrating portion penetrating in the thickness direction, and at least a part of the first metal wiring and the second metal wiring face the opening of the penetrating portion, respectively. And
The first metal wiring and the second metal wiring are configured such that a current flows through the first metal wiring to generate electromigration, thereby causing the first metal wiring to have a thickness inside the through portion. A semiconductor device characterized in that it is electrically connected by a fine metal wire formed by growing in a direction.   The semiconductor device according to claim 1, wherein the first metal wiring is made of Al or an alloy containing Al as a main component.   The semiconductor device according to claim 1, wherein the thin metal wire is formed so as not to contact an inner side surface of the penetrating portion.   The semiconductor device according to claim 1, wherein the first metal wiring is covered with an insulating film.   2. The plurality of through portions are provided for a set of the first metal wiring and the second metal wiring, and the thin metal wires are formed in each through portion. The semiconductor device according to claim 4.   The first substrate is an SOI (Silicon on Insulator) substrate in which the element formation substrate on which the first element is formed is stacked on a support substrate via a buried oxide film. The semiconductor device according to claim 1. A first substrate having a first element on the substrate surface and a first metal wiring electrically connected to the first element; a second element on the substrate surface; And a second substrate having a second metal wiring connected thereto,
A step of penetrating through the first substrate so that one opening faces at least a part of the first metal wiring from the back surface of the first substrate;
Bonding the second substrate to the first substrate so that the other opening of the penetrating portion faces at least a part of the second metal wiring;
By causing a current to flow through the first metal wiring to generate electromigration, the first metal wiring is grown in the thickness direction inside the through portion, and the first metal wiring and the second metal wiring are grown. Forming a thin metal wire that electrically connects the metal wiring of
A method for manufacturing a semiconductor device, comprising:   8. The method of manufacturing a semiconductor device according to claim 7, wherein the first metal wiring is made of Al or an alloy containing Al as a main component.   9. The method of manufacturing a semiconductor device according to claim 7, wherein the thin metal wire is formed so as not to come into contact with an inner surface of the penetrating portion.   The method for manufacturing a semiconductor device according to claim 7, wherein the first metal wiring is covered with an insulating film.   11. The plurality of through portions are formed for a set of the first metal wiring and the second metal wiring, and the thin metal wires are formed in each through portion. The manufacturing method of the semiconductor device as described in any one of these.   As the first substrate, an element formation substrate on which the first element is formed is an SOI (Silicon on Insulator) substrate formed on a support substrate through a buried oxide film. The method for manufacturing a semiconductor device according to claim 7.

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