JP2006186586A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device capable of preventing an organic protection film coating the outer face of a coil-like antenna from being peeled off and excellent in durability and reliability. <P>SOLUTION: The semiconductor device is composed of a semiconductor chip 1 on which a required semiconductor circuit and a bonding pad 1a are formed, an inorganic protection film 2 formed on a circuit forming face of the semiconductor chip 1, a first organic protection film 3 formed on the inorganic protection film 2, the coil-like antenna 4 formed on the first organic protection film 3 and electrically connected with the bonding pad 1a, and a second organic protection film 5 coating the outer face of the coil-like antenna 4. At least the outer peripheral side of the outermost peripheral turn in a wall face 4a of the coil-like antenna 4 is inclined so that the face not contacting with the first organic protection film 3 is projected in the outer peripheral direction of the semiconductor chip 1 compared with the face contacting with the first organic protection film 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna-integrated semiconductor device, and more particularly to a cross-sectional shape of a coiled antenna formed on a semiconductor chip.

  Information carriers such as cards, tags, or coins that are equipped with semiconductor chips have abundant amounts of information and high security, so they are widely used in fields such as transportation, distribution, and information communication. . In particular, an information carrier equipped with an antenna-integrated semiconductor device in which an antenna is formed on a semiconductor chip is much smaller than an information carrier in which an antenna is set or formed on a substrate holding a semiconductor chip. In addition, there is an advantage that even when the substrate is elastically deformed by the action of an external force, the disconnection of the antenna cannot occur essentially, so that it is expected to be used in a wider range of fields in the future.

  By the way, an antenna-integrated semiconductor device includes a step of forming a first organic protective film so as to open a bonding pad on an inorganic protective film formed so as to open the bonding pad in the state of a wafer. And a step of uniformly sputtering the conductive film on the first organic protective film, a step of uniformly forming a photoresist layer on the conductive film, an exposure process, a development process and a baking process on the photoresist layer, Forming an opening corresponding to the required antenna shape, performing electroplating using the conductive film as a cathode, and forming an antenna corresponding to the shape of the opening formed in the photoresist layer, surplus conductive film and photoresist A step of removing the layer, a step of coating the outer surface of the antenna with the second organic protective film, and a scriber in which the wafer is preset Taken along the emission is produced through a step of taking out the respective pieces of product. The inorganic protective film and the first organic protective film function as a circuit protective film that protects the circuit forming surface of the wafer, and the second organic protective film serves as an antenna protective film for protecting the antenna. Function.

Conventionally, the exposure conditions, development conditions, and baking conditions of the photoresist layer are such that the wall surface of the antenna formation opening formed in the photoresist layer is substantially perpendicular to the first organic protective film over the entire circumference. It is set. Therefore, in the semiconductor device as a product, as shown in FIG. 5, the inner peripheral wall surface 4 a and the outer peripheral wall surface 4 b are formed on the first organic protective film 3 over the entire circumference. On the other hand, a coiled antenna 4 that is substantially perpendicular to the coil is formed. In FIG. 5, reference numeral 1 denotes a semiconductor chip, 2 denotes an inorganic protective film formed on the semiconductor chip 1, and 5 denotes a second organic protective film.
JP 2002-92568 A

  By the way, in an antenna integrated semiconductor device, since the antenna size is limited to the size of the semiconductor chip or less, it is wound in a coil shape to increase the communication distance with the external device as much as possible, and the required feeding point is The outer periphery of the antenna (this is referred to as a “coiled antenna” in the present specification) electrically connected to the bonding pad of the semiconductor chip 1 is formed to the very vicinity of the outer periphery of the semiconductor chip 1. For this reason, the adhesion area between the first organic protective film 3 and the second organic protective film 5 in the outer peripheral portion of the semiconductor chip 1 is inevitably small and is affected by the chemical or physical external environment. Further, there is a problem that the second organic protective film 5 is easily peeled off from the interface with the first organic protective film 3.

  In the case where the organic protective film corresponding to the second organic protective film 5 is formed directly on the inorganic protective film 2 without the first organic protective film 3, from the interface with the inorganic protective film 2. The peeling of the organic protective film becomes a problem.

  The present invention has been made to eliminate such deficiencies in the prior art, and an object of the present invention is to provide a semiconductor device excellent in durability and reliability because the organic protective film covering the outer surface of the coiled antenna is difficult to peel off. Is to provide.

  In order to solve the above problems, the present invention forms a coiled antenna for non-contact communication on a semiconductor chip via a circuit protective film, and covers the outer surface of the coiled antenna with an antenna protective film. In the semiconductor device according to the present invention, the outermost peripheral portion of the wall surface of the coiled antenna is formed in a shape in which a surface that does not contact the circuit protective film protrudes in an outer peripheral direction of the semiconductor chip with respect to a surface that contacts the circuit protective film. Made the configuration.

  In order to solve the above problems, the present invention forms a coiled antenna for non-contact communication on a semiconductor chip via a circuit protective film, and covers the outer surface of the coiled antenna with an antenna protective film. In the semiconductor device, the cross-sectional shape of the coiled antenna is formed in an inverted trapezoidal shape with a narrow surface in contact with the circuit protective film and a wide surface not in contact with the circuit protective film.

  According to such a configuration, even when the outer diameter of the coiled antenna is the same as that of the conventional product, the adhesion area between the circuit protective film and the antenna protective film in the outer peripheral portion of the semiconductor device can be increased. The antenna protective film can be prevented from peeling from the outer peripheral portion of the semiconductor device without sacrificing the communication distance between the two.

  The wall surface of the coiled antenna is ideally formed in a smooth inclined surface, but the wall surface of the coiled antenna is smooth depending on the exposure conditions, development conditions, baking conditions, etc. of the photoresist layer. It may be formed in a step shape instead of an inclined surface. However, in any case, the effect of increasing the adhesion area between the circuit protective film and the antenna protective film in the outer peripheral portion of the semiconductor device is effective, and the effect of suppressing the peeling of the antenna protective film is equivalent.

  The semiconductor device of the present invention has a shape in which at least the outermost wall surface of the coiled antenna wall has a surface that does not contact the circuit protection film with respect to the surface that contacts the circuit protection film, protruding in the outer peripheral direction of the semiconductor chip. Therefore, when the outer diameter of the coiled antenna is the same, the adhesion area between the circuit protective film and the antenna protective film at the outer peripheral portion can be increased as compared with the semiconductor device in which the wall surface of the coiled antenna is formed vertically. The durability and reliability of the semiconductor device can be improved without sacrificing the communication distance with the external device.

  A semiconductor device according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partially broken plan view of the semiconductor device according to the first embodiment, and FIG. 2 is a cross-sectional view of the main part of the semiconductor device according to the first embodiment.

  As shown in FIGS. 1 and 2, the semiconductor device of this example excludes a semiconductor chip 1 in which a semiconductor circuit (not shown) is formed and a bonding pad 1a is formed at a predetermined position, and a bonding pad 1a forming portion. An inorganic protective film 2 formed on the circuit forming surface of the semiconductor chip 1, a first organic protective film 3 formed on a portion of the inorganic protective film 2 excluding a portion where the bonding pad 1a is formed, and a first organic protective film A coiled antenna 4 formed on the film 3 and electrically connected to the bonding pad 1a, and a second organic protective film 5 covering the outer surface of the coiled antenna 4 are formed. Between the outer peripheral edge (end face) and the outer peripheral edge of each of the protective films 2, 3, 5, the non-forming portion 6 of the protective film 2, 3, 5 is provided.

  The bonding pad 1a is formed of aluminum, and the antenna 4 is formed of a copper plating film. The inorganic protective film 2 is formed of aluminum or silicon oxide or nitride. On the other hand, the 1st and 2nd organic protective films 3 and 5 are formed with the resin material which has a required physical property. Any resin material having required physical properties can be used as the resin material, but it is particularly preferable to form the resin material with a photosensitive resin material such as photosensitive polyimide in order to facilitate the manufacture of the semiconductor device.

  As shown in FIG. 1, the coiled antenna 4 is formed in a square spiral shape wound at a constant pitch. As shown in FIG. 2, the wall surface 4 a of the coiled antenna 4 is a surface in which only the outer peripheral side of the outermost turn is in contact with the first organic protective film 3 with respect to the film surface of the first organic protective film 3. The surface that is not in contact with the first organic protective film 3 is inclined so as to protrude in the outer peripheral direction of the semiconductor chip 1, and the other wall surfaces are perpendicular to the film surface of the first organic protective film 3. Is formed.

  A semiconductor device having such a wall shape is formed by exposing a photoresist layer applied on a wafer to an exposure process, a development process, and a baking process to form an opening corresponding to the antenna shape in the photoresist layer. Can be produced by over-developing or over-baking.

  In the semiconductor device of this example, the outer peripheral wall surface 4 a of the coiled antenna 4 has a surface that does not contact the first organic protective film 3 with respect to a surface that contacts the first organic protective film 3. When the outer diameter of the coiled antenna 4 is the same, the first organic protective film 3 on the outer peripheral portion of the coiled antenna 4 and the wall surface 4a of the coiled antenna 4 is formed more vertically than the semiconductor device formed vertically. The adhesion area with the second organic protective film 5 can be increased. Therefore, the durability and reliability of the semiconductor device can be improved without sacrificing the communication distance with the external device.

  Next, a second embodiment of the semiconductor device according to the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view of a main part of the semiconductor device according to the second embodiment.

  In the semiconductor device of this example, the wall surface 4a at the outermost peripheral portion of the coiled antenna 4 is not formed in a smooth inclined surface shape, but is formed in a stepped shape. Other parts are the same as those of the semiconductor device according to the first embodiment. Whether the outermost wall surface 4a of the coiled antenna 4 is formed into a smooth inclined surface or a stepped uneven shape depends on the exposure conditions, development conditions, baking conditions, etc. of the photoresist layer 12. Decide. Even when the wall surface 4a of the coiled antenna 4 is formed in a step shape as in the semiconductor device of this example, the first organic protective film 3 and the second organic protective film 5 are bonded to each other at the outer peripheral portion of the semiconductor device. The area can be increased, and the durability and reliability of the semiconductor device can be improved.

  Next, a third embodiment of the semiconductor device according to the present invention will be described with reference to FIG. FIG. 4 is a fragmentary cross-sectional view of the semiconductor device according to the third embodiment.

  The semiconductor device of this example is characterized in that the cross-sectional shape of the coiled antenna 4 is formed in an inverted trapezoidal shape with a narrow surface in contact with the first organic protective film 3 and a wide surface not in contact with the first organic protective film 3. And Even in such a configuration, the outer peripheral wall surface 4 a of the coiled antenna 4 is not in contact with the first organic protective film 3 with respect to the surface in contact with the first organic protective film 3 in the outer peripheral direction of the semiconductor chip 1. Overhanging shape can be achieved. Therefore, it has the same effect as the semiconductor device according to the first embodiment.

  In each of the above embodiments, the semiconductor device provided with the first organic protective film 3 has been described as an example. However, the gist of the present invention is not limited to this, and the first organic protective film 3 is not limited thereto. The same can be applied to a semiconductor device in which an organic protective film corresponding to the second organic protective film 5 is formed directly on the inorganic protective film 2.

1 is a partially broken plan view of a semiconductor device according to a first embodiment. 1 is a cross-sectional view of main parts of a semiconductor device according to a first embodiment. It is principal part sectional drawing of the semiconductor device which concerns on 2nd Embodiment. It is principal part sectional drawing of the semiconductor device which concerns on 3rd Embodiment. It is principal part sectional drawing of the semiconductor device which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 1a Bonding pad 2 Inorganic protective film 3 1st organic protective film 4 Coiled antenna 5 2nd organic protective film 6 The non-formation part of a protective film

Claims (4)

  A coiled antenna for non-contact communication is formed on a semiconductor chip via a circuit protective film, and a semiconductor device in which an outer surface of the coiled antenna is covered with an antenna protective film, The semiconductor device according to claim 1, wherein the outermost peripheral portion is formed in a shape in which a surface not in contact with the circuit protective film projects from a surface in contact with the circuit protective film in an outer peripheral direction of the semiconductor chip.   In a semiconductor device in which a coiled antenna for non-contact communication is formed on a semiconductor chip via a circuit protective film, and the outer surface of the coiled antenna is covered with an antenna protective film, a cross-sectional shape of the coiled antenna Is formed in an inverted trapezoid having a narrow surface in contact with the circuit protective film and a wide surface not in contact with the circuit protective film.   The semiconductor device according to claim 1, wherein a wall surface of the coiled antenna is formed in a smooth inclined surface shape.   The semiconductor device according to claim 1, wherein a wall surface of the coiled antenna is formed in a stepped shape.

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