JP2007189499A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which has an on-chip antenna, the semiconductor device being capable of improving antenna sensitivity to make a communication distance longer. <P>SOLUTION: The semiconductor device 10 of the present invention includes a semiconductor substrate having an electrode 2 on at least one surface, a first magnetic body 11 provided covering the one surface of the substrate, a first insulating resin layer 12 provided on the first magnetic body, a first conduction section 13 which is provided on the first insulating resin layer and electrically connected to the electrode, a second insulating resin layer 14 provided on the first conduction section, and a second conduction section 15 provided on the second insulating resin layer 14. The first conduction section and second conduction section are electrically connected to constitute an antenna circuit 15a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor device provided with a small antenna circuit on a semiconductor substrate such as a silicon wafer, and more particularly to a semiconductor device with improved antenna sensitivity and a longer communication distance.

  In recent years, there has been proposed a semiconductor module that has an IC chip and an antenna coil for wireless communication, and transmits and receives signals using the antenna coil. This semiconductor module is a wireless authentication system called RF-ID, has a high information processing capability by an IC chip, and can read and write signals without contact. For this reason, in recent years, it has become popular in fields such as access control, electronic money, anti-counterfeiting technology and logistics. Such a semiconductor module generally has a spiral antenna coil formed on the same surface on an insulating substrate provided with an IC chip, and includes a card type, a tag type and a coin type. In order to further reduce the size and cost of a semiconductor module, an on-chip antenna in which an antenna coil is formed by applying a semiconductor process on the same surface and directly above an IC chip provided with electrodes has been proposed.

The conventional on-chip antenna technology as described above is a type of antenna that operates by inductive coupling between a reader / writer and an on-chip antenna at an operating frequency such as 13.56 MHz. In the antenna of the operation method, since the communication distance of the antenna is determined depending on the opening area of the antenna, the communication distance is very short even if formed on a very small area such as an IC chip, and the contact level or There is a problem that data cannot be transmitted / received or read unless the distance is 1 to 2 mm. As a result, the on-chip antenna of the prior art has a limited use because of the short communication distance, and the spread of the on-chip antenna is stagnant.
Japanese Patent No. 3347138

  The present invention has been proposed in view of such a conventional situation, and provides a semiconductor device capable of improving antenna sensitivity and extending a communication distance in a semiconductor device including an on-chip antenna. For the purpose.

According to a first aspect of the present invention, there is provided a semiconductor device including a semiconductor substrate having an electrode on at least one surface, a first magnetic body provided so as to cover one surface of the substrate, and the first magnetic body. A first insulating resin layer provided, a first conductive portion provided on the first insulating resin layer and electrically connected to the electrode, and provided on the first conductive portion A second insulating resin layer, and a second conductive portion provided on the second insulating resin layer, wherein the first conductive portion and the second conductive portion are electrically connected. It is characterized by constituting an antenna circuit.
A semiconductor device according to a second aspect of the present invention is the semiconductor device according to the first aspect, wherein the antenna circuit includes a plurality of circular portions having substantially the same pattern, and the circular portions are sequentially shifted to form a spiral shape. It is characterized by that.
According to a third aspect of the present invention, in the semiconductor device according to the second aspect, the antenna circuit includes a second magnetic body in a region inside the second conductive portion constituting the innermost circumference of the spiral shape. It is characterized by arranging.
According to a fourth aspect of the present invention, in the semiconductor device according to the third aspect, the first magnetic body and the second magnetic body are arranged at positions where they overlap each other.

  In the semiconductor device of the present invention, by providing the magnetic body (first magnetic body) on the semiconductor substrate, the magnetic flux collection effect can be enhanced, thereby improving the antenna sensitivity and increasing the communication distance. Furthermore, the above-described effect can be further enhanced by providing a magnetic body (second magnetic body) in a portion corresponding to the inner side of the innermost circumference of the antenna circuit having a spiral shape.

  Hereinafter, an embodiment of a semiconductor device according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an example of the semiconductor device of the present invention, and FIG. 2 is a plan view of the semiconductor device shown in FIG.
In this semiconductor device 10, an electrode 2 and a passivation film 3 of an integrated circuit (IC, not shown) are formed on the surface of a semiconductor substrate 1 on which an integrated circuit (not shown) is formed.
Further, the semiconductor device 10 includes a first magnetic body 11 provided on the passivation film 3 of the semiconductor substrate 1, a first insulating resin layer 12 provided on the first magnetic body 11, A first conductive portion 13 provided on the insulating resin layer 12, a second insulating resin layer 14 provided on the first insulating resin layer 12 and the first conductive portion 13, and a second A second conductive portion 15 provided on the insulating resin layer 14 and a second magnetic body 16 are included.

In the semiconductor device 10, the first conductive portion 13 and the second conductive portion 15 are electrically connected. The second conductive portion 15 includes an antenna circuit 15a, and the antenna circuit includes a plurality of circulation portions having substantially the same pattern, as shown in FIG. It has a spiral shape.
In FIG. 1, only two antenna circuits 15a (for two turns) are shown, but actually, as shown in FIG. 2, a plurality of turning parts are provided. At this time, the number of the circulating parts is not particularly limited, and is appropriately determined depending on the length of the circulating part, the resonance frequency to be responsive, the response sensitivity, and the like.

In the semiconductor device 10 of the present invention, the first magnetic body 11 and the second magnetic body 16 are arranged, so that the antenna sensitivity of the antenna circuit 15a can be improved.
In particular, in the antenna circuit 15a, it is preferable that the second magnetic body is disposed in a region inside the second conductive portion constituting the innermost circumference of the spiral shape. By arranging the second magnetic body 16 on the inner part of the antenna circuit 15a having a spiral shape, the magnetic flux collecting effect is further increased, and the antenna sensitivity can be further increased.

  Moreover, it is preferable that the first magnetic body 11 and the second magnetic body 16 are arranged at positions where they overlap each other. By arranging the first magnetic body 11 and the second magnetic body 16 in an overlapping position, the magnetic flux collection effect is further increased, and the antenna sensitivity can be further increased. Furthermore, it is more preferable that the first magnetic body 11 and the second magnetic body 16 are connected. As a result, further improvement in sensitivity can be expected.

The semiconductor substrate 1 is provided with, for example, an Al pad as an electrode 2 on at least one surface of a base material 1a whose surface layer forms an insulating portion (not shown), and further a passivation film 3 (passivation) such as SiN or SiO ₂ on the surface. Insulating film) is formed. The passivation film 3 is provided with an opening 3a at a position aligned with the electrode 2, and the electrode 2 is exposed through the opening 3a. The passivation film 3 can be formed by, for example, the LP-CVD method, and the film thickness is, for example, 0.1 to 0.5 μm.
Here, the electrode 2 for electrically connecting the second conductive portion 15 to the integrated circuit is provided at two locations (only one location is shown in the figure) of the surface of the semiconductor substrate 1.

  The semiconductor substrate 1 may be a semiconductor wafer such as a silicon wafer, or may be a semiconductor chip obtained by cutting (dicing) the semiconductor wafer into chip dimensions. When the semiconductor substrate 1 is a semiconductor chip, first, a plurality of semiconductor elements, ICs, induction elements, etc. are formed on a semiconductor wafer and then cut into chip dimensions to obtain a plurality of semiconductor chips. Can do.

  The first magnetic body 11 has an opening 11 a formed at a position aligned with the electrode 2. The first magnetic body 11 is made of, for example, NiZn-based ferrite, amorphous metal such as CoNbZr, ferromagnetic metal such as NiFe (permalloy), and the thickness thereof is, for example, 1 to 10 μm.

  The first magnetic body 11 can be formed by, for example, a plating method or a sputtering method. The opening 11a can be formed by, for example, patterning using a photolithography technique or a lift-off method.

  The first insulating resin layer 12 has an opening 12a formed at a position aligned with the electrode 2 and an opening 12b formed at a position where a second magnetic body described later is provided. The first insulating resin layer 12 is made of, for example, polyimide resin, epoxy resin, silicone resin, or the like, and has a thickness of, for example, 1 to 30 μm.

  The first insulating resin layer 12 can be formed by, for example, a spin coating method, a printing method, a laminating method, or the like. The opening 12a can be formed by, for example, patterning using a photolithography technique.

  The first conductive portion 13 is a rewiring portion (underpass) that electrically connects the electrode 2 and the antenna circuit 15a. One end of the first conductive portion 13 penetrates the first insulating resin layer 12 through the opening 12 a and is electrically connected to the electrode 2. Further, the other end portion of the first conductive portion 12 extends to a position aligned with the opening portion 14a.

  For example, Cu or the like is used as the material of the first conductive portion 13, and the thickness thereof is, for example, 1 to 20 μm. Thereby, sufficient electrical conductivity is obtained. The first conductive portion 13 can be formed by, for example, a plating method such as an electrolytic copper plating method, a sputtering method, a vapor deposition method, or a combination of two or more methods.

  The second insulating resin layer 14 has an opening 14 a that is opened at a position along the surface of the semiconductor substrate 1 that is different from the opening 12 a. The opening 14 a is formed at a position aligned with one end of the second conductive portion 15. Moreover, it has the opening part 14b formed in the position in which the 2nd magnetic body 16 mentioned later is provided.

  The second insulating resin layer 14 is made of, for example, polyimide resin, epoxy resin, silicone resin, etc., and the thickness thereof is, for example, 1 to 30 μm. The second insulating resin layer 14 can be formed by, for example, a spin coating method, a printing method, a laminating method, or the like. The openings 14a and 14b can be formed by patterning using a photolithography technique, for example.

  The second conductive portion 15 has an antenna circuit 15a. As shown in FIG. 2, the antenna circuit 15a includes a plurality of circular portions having substantially the same pattern, and the circular portions are arranged in a shifted manner in order to form a spiral shape. One end portion of the second conductive portion 15 passes through the second insulating resin layer 14 through the opening portion 14 a and is connected to the end portion of the first conductive portion 13.

  For example, Cu or the like is used as the material of the second conductive portion 15, and the thickness thereof is, for example, 1 to 20 μm. Thereby, sufficient electrical conductivity is obtained. The second conductive portion 15 can be formed by, for example, a plating method such as an electrolytic copper plating method, a sputtering method, a vapor deposition method, or a combination of two or more methods.

  The second magnetic body 16 has the first insulating resin layer 12 and the second insulating resin layer 14 disposed in an area inside the spiral innermost periphery of the antenna circuit via the opening 12b and the opening 14a. It is arranged through.

  As the material of the second magnetic body 16, for example, NiZn ferrite, amorphous metal such as CoNbZr, and ferromagnetic metal such as NiFe (permalloy) can be used. NiZn ferrite paste is particularly preferable. The thickness is, for example, 10 to 50 μm. The second magnetic body 16 is preferably formed by a printing method using a mask, but is not limited thereto, and may be a plating method, a sputtering method, or the like.

  Note that a sealing resin layer (not shown) may be provided on the second conductive portion 15. The sealing resin layer is made of, for example, polyimide resin, epoxy resin, silicone resin, etc., and the thickness thereof is, for example, 10 to 15 μm. The sealing resin layer is provided with an opening for outputting a terminal to the outside. Further, on the sealing resin layer, structures such as output terminals to the outside such as bumps can be added as necessary.

Next, a method for manufacturing the semiconductor device shown in FIG. 1 will be described.
First, as shown in FIG. 3A, a semiconductor substrate 1 having an integrated circuit (not shown), an electrode 2 and a passivation film 3 is prepared. As described above, the semiconductor substrate 1 has the electrode 2 and the passivation film 3 formed on one surface of the substrate 1 a, and the passivation film 3 is provided with the opening 3 a at a position aligned with the electrode 2. It is a semiconductor wafer. The passivation film 3 is formed by, for example, LP-CVD, and the film thickness is, for example, 0.1 to 0.5 μm.

Next, as shown in FIG. 3B, a first magnetic body 11 having an opening 11 a is formed on the passivation film 3 of the semiconductor substrate 1. The thickness is, for example, 1 to 30 μm.
For example, the first magnetic body 11 is formed by depositing a film made of the above magnetic material on the entire surface of the passivation film 3 by, for example, plating, sputtering, or the like, and then performing patterning using a photolithography technique, for example. It can be formed by forming the opening 11a at a position aligned with the electrode 2.

Next, as shown in FIG. 3C, a first insulating resin layer 12 having openings 12 a and 12 b is formed on the first magnetic body 11. The thickness is, for example, 1 to 30 μm.
Such a first insulating resin layer 12 is formed by, for example, forming a film made of the above resin on the entire surface of the first magnetic body 11 by, for example, a spin coating method, a printing method, a laminating method, etc. By using patterning or the like, the opening 12a is formed at a position aligned with the electrode 2, and the opening 12b is formed at a position where the second magnetic body 16 is provided (a region inside the innermost circumference of the antenna circuit having a spiral shape). Can be formed.

  Next, as shown in FIG. 3 (d), the first conductive portion 13 is formed on the first insulating resin layer 12 at a position aligned with the electrode 2 on the semiconductor substrate 1. The method of forming the first conductive portion 13 having a thickness of, for example, 1 to 20 μm in a predetermined region is not particularly limited, but for example, the following method can be used.

Here, an example of a suitable method for forming the first conductive portion 13 will be described.
First, a thin seed layer (not shown) for electrolytic plating is formed on the entire surface of the first insulating resin layer 11 or a necessary region by sputtering or the like. The seed layer is, for example, a laminated body made of a Cu layer and a Cr layer formed by a sputtering method, or a laminated body made of a Cu layer and a Ti layer. Moreover, an electroless Cu plating layer may be sufficient, the metal thin film layer formed by the vapor deposition method, the apply | coating method, the chemical vapor deposition method (CVD method), etc. may be combined, and said metal layer formation method is combined. Also good.

  Next, a resist film (not shown) for electrolytic plating is formed on the seed layer. The resist film is provided with an opening in a region where the first conductive portion 12 is to be formed, and the seed layer is exposed in the opening. The resist film can be formed by, for example, patterning using a photolithography technique, a method of laminating a film resist, a method of spin-coating a liquid resist, or the like.

  Then, a first conductive portion 13 made of Cu or the like is formed on the exposed seed layer using the resist film as a mask by an electrolytic plating method or the like. As described above, after the first conductive portion 13 is formed in a desired region, unnecessary resist films and seed layers are removed by etching, and the first conductive portion 13 is formed in a portion other than the region where the first conductive portion 13 is formed. The insulating resin layer 12 is exposed [see FIG. 3 (d)].

Next, as shown in FIG. 3E, a second insulating resin layer 14 having an opening is formed on the first conductive portion 13. The thickness is, for example, 1 to 30 μm.
Such a second insulating resin layer 14 is formed by, for example, forming a film made of the above resin on the entire surface by, for example, a spin coating method, a printing method, a laminating method, etc., and then patterning using, for example, a photolithography technique. The opening 14a is formed at a position that matches the pad that electrically connects the first conductive portion 13 and the second conductive portion 15, and the second magnetic body 16 is provided (the position of the antenna circuit having a spiral shape). It can be formed by forming the opening 14b in a region inside the inner periphery).

Next, as shown in FIG. 3 (f), a second conductive portion 15 having an antenna circuit 15 a having a spiral shape is formed on the second insulating resin layer 14. The thickness is, for example, 1 to 20 μm.
Since the method of providing the second conductive portion 15 in the predetermined region can be performed in substantially the same manner as the method of providing the first conductive portion 13, detailed description thereof is omitted.

  Next, as shown in FIG. 3G, openings 12b... Are formed in a region inside the innermost periphery of the spiral antenna circuit. A second magnetic body 16 is formed through the first first insulating resin layer 12 and the second insulating resin layer 14 via 14b. The thickness is, for example, 10 to 50 μm. The second magnetic body 16 is preferably formed by a printing method using a mask, but is not limited thereto, and may be a plating method, a sputtering method, or the like.

After the second magnetic body 16 is formed, a semiconductor chip on which the antenna circuit is packaged can be obtained by dicing a semiconductor wafer on which various structures such as the antenna circuit are formed into predetermined dimensions.
In the case where a sealing resin layer (not shown) is formed on the second conductive portion 15, for example, a photosensitive resin such as a photosensitive polyimide resin is patterned by a photolithography technique so that an opening is formed at a desired position. An encapsulating resin layer can be formed. The thickness is, for example, 1 to 30 μm. In addition, the formation method of the sealing resin layer is not limited to this method.

  In the semiconductor device obtained as described above, the magnetic body (first magnetic body) is provided on the semiconductor substrate, and further, the magnetic body (the second magnetic body) is disposed on the inner side of the innermost circumference of the antenna circuit having a spiral shape. The magnetic collecting effect can be enhanced. As a result, the antenna sensitivity can be improved and the communication distance can be increased.

  Although the semiconductor device of the present invention has been described above, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention.

  Further, in the figure, only a portion corresponding to one antenna circuit on the semiconductor substrate is illustrated, but the present invention can also be applied to a semiconductor device including a plurality of antenna circuits.

  The present invention can be applied to various semiconductor devices having an antenna circuit.

It is sectional drawing which shows an example of the semiconductor device which concerns on this invention. FIG. 2 is a plan view of the semiconductor device shown in FIG. 1. FIG. 3 is a cross-sectional view showing an example of a method for manufacturing the semiconductor device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate, 2 Electrode, 3 Passivation film | membrane, 10 Semiconductor device, 11 1st magnetic body, 12 1st insulating resin layer, 13 1st electroconductive part, 14 2nd insulating resin layer, 15 2nd electroconductivity Part, 15a antenna circuit, 16 2nd magnetic body.

Claims (4)

A semiconductor substrate having electrodes on at least one surface;
A first magnetic body provided to cover one surface of the substrate;
A first insulating resin layer provided on the first magnetic body;
A first conductive portion provided on the first insulating resin layer and electrically connected to the electrode;
A second insulating resin layer provided on the first conductive portion;
A second conductive portion provided on the second insulating resin layer, and a semiconductor device comprising:
The semiconductor device, wherein the first conductive portion and the second conductive portion are electrically connected to constitute an antenna circuit.   2. The semiconductor device according to claim 1, wherein the antenna circuit includes a plurality of surrounding portions having substantially the same pattern, and each of the surrounding portions is arranged so as to be shifted in order and has a spiral shape.   3. The semiconductor device according to claim 2, wherein the antenna circuit includes a second magnetic body arranged in a region inside the second conductive portion constituting the innermost circumference of the spiral shape. 4. The semiconductor device according to claim 3, wherein the first magnetic body and the second magnetic body are arranged at positions overlapping each other.

Images