JP5589617B2 - Thin film capacitor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a thin film capacitor and a method for manufacturing the same.

  Conventionally, a thin film capacitor using a dielectric film is generally known (see, for example, Patent Document 1).

  For the purpose of improving the withstand voltage of such a thin film capacitor, for example, by making a structure in which two capacitors are connected in series, the voltage applied to the dielectric film is reduced to approximately ½, A technique for improving the withstand voltage approximately twice has been proposed (see, for example, Patent Document 2).

  More specifically, in the capacitor described in Patent Document 2, a first electrode (lower electrode) is formed on a substrate, a dielectric film is formed to cover the lower electrode, and the lower electrode is further formed. A pair of second electrodes (upper electrodes) juxtaposed on the dielectric film at both ends of the upper electrode are formed, these are covered with a protective layer (insulating layer), and an opening is formed in the protective layer above the upper electrode And a series structure in which the terminal electrode is conductor-connected using the opening.

JP-A-5-47586 JP 2004-63949 A

  By the way, in the above-mentioned conventional capacitor series (particularly described in Patent Document 2), the distance between the two capacitors, that is, the distance between the upper electrodes juxtaposed on the lower electrode is considerably separated, Since the path of the current flowing between the capacitors is one layer of the lower electrode, the resistance value of the lower electrode increases in proportion to the distance between the capacitors, and the electrical characteristics and functions of the capacitor deteriorate. was there. In addition, since the capacitor is formed by the corner portion of the lower electrode, the withstand voltage may be lowered due to electric field concentration at the corner portion of the lower electrode.

  In the conventional configuration, since the capacitor has only a pair of the upper electrode (second electrode) and the lower electrode (first electrode), the thin film capacitor is mounted, that is, the upper electrode (second electrode). When an electronic component package, electronic component module, electronic device, or the like is manufactured by connecting and fixing the electrode) to an external substrate by soldering or the like, the capacitor is subjected to external stress (external force) or external load (including impact load) In this case, those stresses and loads are concentrated on the upper electrode (second electrode) or the lower electrode (first electrode) through the solder joint portion of the upper electrode (second electrode), and such external force or load is applied. The resistance to tended to be fragile.

  Therefore, the present invention has been made in view of such circumstances, and the resistance value of the lower electrode can be reduced, whereby the thin film capacitor can sufficiently enhance the electrical characteristics and functions of the thin film capacitor. And it aims at providing the manufacturing method.

In order to solve the above problems, a thin film capacitor according to the present invention includes a first electrode (so-called lower electrode; may be a layer) formed on a substrate, and a dielectric film (also a layer) on the first electrode. At least two second electrodes (so-called upper electrodes; which may be layers) which are juxtaposed in opposition to each other and spaced apart from each other, and at least on the first electrode A protrusion (intermediate conductor portion) disposed between each of the two second electrodes and protruding upward from the first electrode , covering at least a part of the dielectric film, and the protrusion; and A protective layer having an opening on each of the at least two second electrodes; and at least a part of each of the at least two second electrodes formed on the protective layer and exposed to the opening of the protective layer; At least two electrically connected And a child electrodes, protruding portions (electrically) is to any of the terminal electrode is not connected. Note that “intermediate” of the “intermediate conductor portion” is for the sake of clarity that the “intermediate conductor” is arranged between at least two second electrodes “between”. There is no need to be placed in a completely intermediate position.

  In such a configuration, at least two capacitors having a configuration in which each of the at least two second electrodes and the first electrode sandwich the dielectric film are connected in series. At this time, since the protruding portion protruding from the first electrode is disposed between the second electrodes on the first electrode, the current between the thin film capacitors flows to the protruding portion in addition to the first electrode. In other words, the resistance value can be decreased by increasing the cross-sectional area of the current path, and thereby the electrical characteristics and functions of the thin film capacitor can be sufficiently enhanced. Further, since the protrusion is provided between the second electrodes, the film thickness of the protrusion is added to the film thickness of the second electrode, so that the electrode film thickness between the capacitors is substantially increased. The resistance to external stress and external load can be improved.

  Here, in the above-described conventional thin film capacitor, the entire thin film capacitor is made of a resin such as polyimide with a relatively wide gap between the steps defined by the lower electrode and the upper electrodes juxtaposed thereon. When covering with a protective layer, the flatness of the protective layer after application cannot be ensured sufficiently due to the step, and in some cases, for example, the end portion of the upper electrode (the part desired to be covered with the protective layer) It can also be assumed that it is exposed to the outside. On the other hand, as described above, by providing the protective layer so that the protective layer disposed between the second electrodes is covered with at least a part (preferably all) of the protrusions, The problem that flatness is impaired can be easily solved. That is, by having a protrusion between the second electrodes and covering the protrusion with a protective layer, the step formed by the second electrode and the first electrode, the protrusion and the first electrode, The distance between the step formed by the step can be made narrower than the distance between the steps defined by the conventional lower electrode and upper electrode structure, thereby ensuring sufficient flatness of the protective layer. it can. In this case, the protective layer may further cover at least a part of each of the at least two second electrodes.

Further, in the vertical section (perpendicular sectional view) of the protruding portion , the protruding portion has a width of the end portion farther from the dielectric film than the end portion on the dielectric film side, for example, a cross-sectional shape Can have a T-shape or a substantially T-shape. According to the shape of the protruding portion, the material of the protective layer made of a resin such as polyimide flows into the first electrode and the lower portion of the protruding portion, and the protective layer is sandwiched between the first electrode and the protruding portion. Since the structure is generated, peeling of the protective layer can be effectively suppressed.

  Furthermore, each of the at least two second electrodes and each horizontal cross-sectional shape (shape in plan view) of the protrusion are not particularly limited, and may be a simple rectangular shape, or at least the second electrode. And at least one of the protrusions may have a bent shape. In this way, when the bent shape is not generated in such at least two second electrodes or protrusions (the first electrode may be in the width direction (longitudinal direction or short direction) of the thin film capacitor). Compared to the case where there is no structure such as at least two second electrodes and protrusions above it), external stress or external load received after mounting the thin film capacitor on an external substrate ( It is possible to have strong resistance against impact load), in particular, stress received from the side surface of the thin film capacitor.

  Further, the protruding portion may be made of the same material as the first electrode, or may be made of a material having a lower electrical resistivity than the material of the first electrode. In particular, if the protruding portion is made of a material having a lower electrical resistivity than the material of the first electrode layer, a large amount of current between the capacitors flows through the protruding portion, so that the resistance value between the capacitors can be further reduced. . As a result, the electrical characteristics and functions of the thin film capacitor can be further enhanced. For example, by reducing the resistance value and sufficiently ensuring the conductivity between the capacitors, the equivalent series resistance (ESR) of the thin film capacitor can be reduced, and the Q (Quality factor) value can be increased. it can.

  The protruding portion may be made of the same material as that of the second electrode. By forming the protrusion and the second electrode at the same time, the manufacturing process is not complicated, and it is advantageous in terms of cost as compared with the case where only the protrusion is separately formed. An increase in resistance component can be prevented, and an improvement in electrical characteristics can be expected.

Furthermore, the thin film capacitor manufacturing method according to the present invention is a method for effectively manufacturing the thin film capacitor of the present invention, and a first electrode (so-called lower electrode; may be a layer) is formed on a substrate. A step of forming at least two second electrodes (so-called upper electrodes; may be layers) facing the first electrode with a dielectric film therebetween and spaced apart from each other; Forming a protrusion on the first electrode between each of the at least two second electrodes and electrically connected to the first electrode; and at least a part of the dielectric film And forming a protective layer covering the protrusion and having an opening on each of the at least two second electrodes, and on the protective layer, the at least two second electrodes exposed to the opening of the protective layer Each of the two electrodes Comprising Ku and forming at least two terminal electrodes which also partially electrically connected, the.

  According to the thin film capacitor and the manufacturing method thereof according to the present invention configured as described above, the thin film capacitor is formed in a position between the second electrode layers on the first electrode layer and electrically connected to the first electrode layer. By having the laminated portion, the cross-sectional area of the current path between the thin film capacitors can be increased, so that the resistance value can be reduced, thereby sufficiently improving the electrical characteristics and functions of the thin film capacitor. it can. Further, by providing the laminated portion between the second electrode layers, resistance to external stress can be improved by increasing the electrode film thickness between the capacitors.

1 is a top view (plan view) showing a schematic structure of a thin film capacitor according to a preferred embodiment of the present invention. It is sectional drawing which follows the II-II line | wire of FIG. (A) thru | or (C) are process drawings which show the procedure which manufactures the thin film capacitor. (A) thru | or (C) are process drawings which show the procedure which manufactures the thin film capacitor. (A) thru | or (B) is process drawing which shows the procedure which manufactures the thin film capacitor. (A) thru | or (B) is process drawing which shows the procedure which manufactures the thin film capacitor. (A) thru | or (B) is process drawing which shows the procedure which manufactures the thin film capacitor. (A) thru | or (C) are process drawings which show the procedure which manufactures the thin film capacitor. (A) thru | or (B) is process drawing which shows the procedure which manufactures the thin film capacitor. It is a top view which shows the modification of the structure of the thin film capacitor by this embodiment. It is sectional drawing which shows the modification of the structure of the thin film capacitor by this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios. Further, the following embodiments are exemplifications for explaining the present invention, and are not intended to limit the present invention only to the embodiments. Furthermore, the present invention can be variously modified without departing from the gist thereof.

<Thin film capacitor>
FIG. 1 is a top view (plan view) showing a schematic structure of a thin film capacitor according to a preferred embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. The thin film capacitor (hereinafter simply referred to as “capacitor”) 1 of the present embodiment has a structure in which two capacitors are connected in series as shown in FIGS. 1 and 2.

  As shown in FIG. 2, the capacitor 1 includes a lower electrode (first electrode) 3, a dielectric film 4, upper electrodes (second electrodes) 5 A and 5 B, and a third electrode on a planar rectangular substrate 2. The electrode (protrusion part) 6, the protective layer 7, and the terminal electrode 8 are laminated | stacked one by one.

  Here, as a base material of the substrate 2, a semiconductor substrate can be used, but is not limited thereto, and for example, a metal substrate, a ceramic substrate, a glass ceramic substrate, a glass substrate, a single crystal substrate, and the like can be used. It is preferable to use a material that is chemically and thermally stable and that generates less stress and easily maintains the smoothness of the surface. In addition, the thickness of the board | substrate 2 can be adjusted suitably as needed.

  The lower electrode 3 is formed on a region inside the outer periphery of the substrate 2. The material of the lower electrode 3 is not particularly limited as long as it is a metal material. For example, it is a base metal material such as Al, Cu, Ni, Al—Cu, Al—Si, Al—Cu—Si, and a semiconductor process. If it is the material used by (4), it is preferable in terms of manufacturing cost and process management.

The dielectric film 4 is made of a thin film formed so as to cover the upper surface and side wall surface of the lower electrode 3 and a part of the upper surface of the substrate 2 outside the lower electrode 3. The location covered by the dielectric film 4 is a location where the upper electrode 5A (5B) is installed on the upper surface of the lower electrode 3, and it is sufficient to include at least a region larger than the installation region of the upper electrode 5A (5B). Whether or not other portions are covered can be adjusted as appropriate. The material of the dielectric film 4 is not particularly limited, and for example, a paraelectric thin film such as SiO ₂ , SiN, Al ₂ 0 ₃ , Zr0 ₂ , Hf0 ₂ , or BaTi0 ₃ , BaSrTi0 ₃ , PbTi0 ₃ A ferroelectric thin film such as can be used.

  The dielectric film 4 has an opening 41 (opening) at a position between the upper electrode 5A and the upper electrode 5B. A third electrode 6 that is electrically connected to the lower electrode 3 is formed at the position of the opening 41. For example, after forming the dielectric film 4, the opening 41 determines the region of the opening (hole, via hole, through hole) with a photoresist, and appropriately performs chemical etching, ion milling, RIE (Reactive Ion Etching), or the like. Using this method, it is possible to easily form the dielectric film 4 by removing the portion of the dielectric film 4 not covered with the resist.

  The upper electrodes 5A and 5B are juxtaposed with the lower electrode 3 so as to face each other with the dielectric film 4 interposed therebetween, and are formed apart from each other. The material of the upper electrodes 5A and 5B is not particularly limited as long as it is a metal material, as with the lower electrode 3, and examples thereof include Al, Cu, Ni, Al—Cu, Al—Si, Al—Cu—Si, and the like. Any base metal material that is used in a semiconductor process is preferable in terms of manufacturing cost and process management.

  Further, as shown in FIG. 1, the horizontal sectional shapes of the upper electrodes 5A and 5B have L-shaped bent shapes, respectively, and the third electrode 6 also has an outer shape of the upper electrodes 5A and 5B. Accordingly, the bent portion 9 is defined in the gap between the upper electrodes 5A and 5B and the third electrode 6. The bent portion 9 is a concept including a gap between each of the upper electrodes 5A and 5B and the third electrode 6 and a bent portion in the horizontal sectional shape of the gap. By adopting such a shape, when such a bent shape is not generated (the lower electrode 3 is linearly extended in the width direction of the capacitor 1, and the upper electrodes 5A and 5B and the third electrode are disposed above the lower electrode 3. 6), the external stress and external load (impact load) received after the capacitor 1 is mounted on an external substrate along the width direction of the capacitor 1, in particular, the side surface of the capacitor 1 It is possible to have a strong resistance to stress received from the like. The shapes of the upper electrodes 5A and 5B are not limited to the L-shape, and can be various shapes together with the shape of the third electrode 6 to be described later. Can be selected as appropriate. Moreover, the capacitor | condenser 1 of this embodiment can also omit the bending part 9, and the horizontal cross-sectional shape of upper electrode 5A, 5B can be made into shapes, such as a square and a rectangle, in this case.

  The third electrode 6 is electrically connected to the lower electrode 3 at a position between the upper electrode 5A and the upper electrode 5B on the lower electrode 3 and at the position of the opening 41 of the dielectric film 4. It is formed and can also be called a protruding portion (intermediate conductor portion) protruding from a so-called lower electrode 3. The material of the third electrode 6 is not particularly limited as long as it is a metal material. For example, the third electrode 6 may be made of the same material as that of the lower electrode 3 or a material having a lower electrical resistivity than the material of the lower electrode 3. Can consist of The material of the third electrode 6 can be made of the same material as that of the upper electrodes 5A and 5B.

  Further, as shown in FIG. 2, the third electrode 6 may have a shape in which the vertical sectional shape of the third electrode 6 includes a T shape (mushroom shape). According to the shape of the third electrode 6, the protective layer 7 made of a resin such as polyimide is sandwiched between the lower electrode 3 and the third electrode 6, and the protective layer 7 made of a resin such as polyimide is peeled off. Can be suppressed. The vertical cross-sectional shape of the third electrode 6 is not limited to the shape including the T-shape, and can be various shapes. In the vertical cross-section (view) of the third electrode 6, It is useful if the width of the end portion on the side farther from the dielectric film 4 (upper part in the figure) is made larger than the end part (part connected to the lower electrode 3 in the lower part in the figure).

  Further, the horizontal cross-sectional shape of the third electrode 6 is a shape having a bent portion 9 in the gap between the upper electrodes 5A and 5B and the third electrode 6, and the gap between the upper electrodes 5A and 5B is as follows. The distance can be a shape that maintains a certain distance or more. For example, as shown in FIG. 1, it may be a shape (Z-shaped shape) along the shape of each of the upper electrodes 5A and 5B.

The protective layer 7 functions as an interlayer insulating film and is formed so as to cover the dielectric film 4, the upper electrodes 5 </ b> A and 5 </ b> B, and the third electrode 6. The protective layer 7 has openings 71 and 72 (holes, via holes, and through holes) for electrically connecting the upper electrodes 5A and 5B and the terminal electrodes 8A and 8B. The material of the protective layer 7 is not particularly limited, and for example, a resin system such as polyimide, BCB (benzocyclobutene), epoxy, or mainly vapor phase deposition such as SiO ₂ , SiN, Al ₂ O _3, etc. Ceramics that can be formed by a method can be used. The openings 71 and 72 can be formed by a method of performing exposure and development using a photomask when a photosensitive resin material is used, while the dielectric film is used when a ceramic material is used. The opening 41 can be formed using the same method.

  The terminal electrodes 8A and 8B are formed on the protective layer 7 and are electrically connected to the upper electrodes 5A and 5B through the openings 71 and 72 of the protective layer 7, respectively. The material of the terminal electrodes 8A and 8B can be formed of the same material as that of the lower electrode 3 or the upper electrodes 5A and 5B, for example. Further, since the terminal electrodes 8A and 8B are portions that are connected to the printed wiring board by solder when the capacitor 1 is mounted on an electronic component, surface treatment in consideration of characteristics such as solder bite and solder wettability is performed. Necessary. Therefore, the terminal electrodes 8A and 8B are preferably formed with a surface layer such as a Ni-based barrier layer-Au surface layer or a Ni-based barrier layer-Sn surface layer on the surface thereof. In the barrier layer, materials such as Ti, Cr, Ni, and Fe can be used, or a multilayer structure can be formed by appropriately combining these materials.

  According to the capacitor 1 configured as described above, by having the third electrode 6 formed in electrical connection with the lower electrode 3 at a position between the upper electrodes 5A and 5B on the lower electrode 3, The current between the capacitors flows to the third electrode 6 in addition to the lower electrode 3, in other words, the cross-sectional area of the current path is increased, thereby reducing the resistance value of the current path, As a result, the electrical characteristics and functions of the capacitor 1 can be sufficiently enhanced.

  In addition, since the conventional series capacitor has only one layer of the lower electrode between the capacitors, there is a problem that resistance to external stress applied to the capacitor is weak after mounting this capacitor. Further, by providing the third electrode 6 between the upper electrodes 5A and 5B, the resistance to external stress can be improved by increasing the electrode film thickness between the capacitors, and the problem can be solved.

  Furthermore, the conventional series capacitor has only the lower electrode 3 having a step between the upper electrode 5A and the upper electrode 5B, and the distance between only the lower electrode 3 between the upper electrodes 5A and 5B is wide. When the protective layer is formed, the center between the upper electrodes 5A and 5B is depressed, and the end of the upper electrode is not covered with the protective layer and may be exposed. However, the capacitor 1 according to the present embodiment may be exposed. As described above, by providing the third electrode 6 between the upper electrode 5A and the upper electrode 5B, the interval between the conventional steps can be narrowed, and the flatness of the protective layer can be ensured.

  Furthermore, by providing the third electrode 6, in addition to the capacitor capacity of the capacitor formed by the upper electrode 5A (5B) -dielectric film 4-lower electrode 3, the upper electrode 5A (5B) -protective layer 7- Capacitor capacity can be obtained also at the third electrode 6, and the capacitor capacity of the entire capacitor 1 can be increased. That is, the capacitor formed by the upper electrode 5A-dielectric film 4-lower electrode 3 and the capacitor formed by the upper electrode 5A-protective layer 7-third electrode 6 function as a parallel capacitor, and the upper electrode A capacitor formed by 5B-dielectric film 4-lower electrode 3 and a capacitor formed by upper electrode 5B-protective layer 7-third electrode 6 function as a parallel capacitor, and these parallel capacitors are connected in series. Can be regarded as a structure.

<Manufacturing method of thin film capacitor>
Here, an example of a method for manufacturing the capacitor 1 having such a configuration will be described below. 3 to 9 are process diagrams showing a procedure for manufacturing the capacitor 1.

(Substrate formation)
First, the substrate 2 is prepared, and the surface thereof is polished and planarized by, for example, a CMP method. Further, when the material of the substrate 2 is a metal or a semiconductor, an insulating layer is formed on the surface of the substrate 2. Note that a plurality of element structures of the capacitor 1 are formed on a single substrate 2 (for example, a fine structure having a line / space of several μm / several μm), and finally an individual unit (individual product). A plurality of capacitors can be obtained. In the following illustration, an element structure portion of one capacitor 1 is illustrated.

(Lower electrode formation)
A lower electrode 3 is formed on the substrate 2 by photolithography and plating. More specifically, for example, first, a base conductor layer (film thickness: about 0.01 to 1 μm) 3a is formed as a seed layer on the surface of the substrate 2 by sputtering or electroless plating (FIG. 3A). )reference). Next, a photoresist is formed on the underlying conductor layer 3a, and is patterned by photolithography into a resist mask M1 for selective plating corresponding to the lower electrode 3 (FIG. 3B).

  Then, the electroconductive (electrolytic) plating is selectively performed on the exposed portion of the underlying conductor layer 3a using the resist mask M1 as a plating mask until the electroplated conductor layer 3b for forming the lower electrode 3 has a desired thickness. Electrodeposition formation. Next, by removing the resist mask M1 and the underlying conductor layer 3a outside the electroplating conductor layer 3b, a lower electrode conductor layer 3 is obtained (FIG. 3C). In FIG. 3C, this conductor layer is indicated by the same symbol as the lower electrode 3.

(Dielectric film formation)
Next, a dielectric film 4 is formed to cover the upper surface end and side wall surface of the lower electrode 3 and a part of the upper surface of the substrate 2 outside the lower electrode 3. More specifically, the dielectric film 4 (thickness: 0.00 mm) is formed on the entire surface of the lower electrode 3 and the exposed substrate 2 by a PVD method such as sputtering, a CVD method, an ALD method, or a solution method. (About 01 to 1 μm) is formed (FIG. 4A).

(Opening formation)
Next, an opening (contact hole) 41 for connecting the lower electrode 3 and the third electrode 6 is formed in the dielectric film 4. More specifically, a resist mask M2 made of a photoresist is formed on the dielectric film 4 and on a portion excluding an opening portion that electrically connects the lower electrode 3 and the third electrode 6. Further, the dielectric film 4 is removed by etching using the resist mask M2 as an etch mask, whereby a part of the dielectric film 4 is removed to form an opening 41, and The dielectric film 4 having the opening 41 is obtained (FIG. 4C).

(First upper electrode and lower layer formation)
Next, the first upper electrodes 51A and 51B of the upper electrodes 5A and 5B for determining the electrode area of the capacitor 1 are formed on the upper surface of the dielectric film 4 in the state shown in FIG. 5, and the lower electrode 3 is exposed. A lower layer portion 61 of the third electrode 6 is formed in the (opening 41). More specifically, for example, a base conductor layer (film thickness: about 0.01 to 1 μm) 5a is sputtered or electrolessly formed as a seed layer on the dielectric film 4 and the lower electrode 3 located in the opening 41. It is formed by plating. Next, a resist mask M3 is disposed over the seed layer (FIG. 5A). Next, a portion of the seed layer that is formed on the lower electrode 3 and is not covered with the resist mask M3 is selectively subjected to electroplating to form a first upper electrode. The conductor layer and the electroplated conductor layer for forming the lower layer part are electrodeposited to a desired thickness. Next, by removing the resist mask and the seed layer outside the electroplating conductor layer, first upper electrode conductor layers 51A and 51B and a lower layer conductor layer 61 are obtained (FIG. 5B). In FIG. 5B, the conductor layer for the first upper electrode is indicated by the same reference numerals as the upper electrodes 51A and 51B, and the conductor layer for the lower part is indicated by the same reference numeral as the lower layer part 61.

(Formation of first protective layer)
Next, the end portions of the first upper electrodes 51A and 51B, the end portions of the lower layer portion 61, the upper surface of the dielectric film 4 formed on the lower electrode 3, and the dielectric film formed on the side wall surface of the lower electrode 3 4 and a first protective layer 73 is formed so as to cover the dielectric film 4 formed on the substrate 2. For example, an uncured photo-curing resin is filled. Thereafter, in a state where the metal mask M4 is placed on a portion where the first protective layer 73 is not formed (FIG. 6A), by performing patterning by photolithography, the end portions of the first upper electrodes 51A and 51B, The dielectric film 4 formed on the substrate 2, the dielectric film 4 formed on the end portion of the lower layer portion 61, the upper surface of the dielectric film 4 formed on the lower electrode 3, the side wall surface of the lower electrode 3, and the dielectric film 4 formed on the substrate 2. A first protective layer 73 is formed to cover (FIG. 6B). In addition, on the upper surfaces of the first upper electrodes 51A and 51B and the lower layer portion 61, the portions connected to the second upper electrodes 52A and 52B and the upper layer portion 62 of the third electrode 6 described later are connected to the first protective layer 73. It is exposed without being covered.

(Second upper electrode and upper layer formation)
Next, the second upper electrodes 52A and 52B connected to the first upper electrodes 51A and 51B, and the upper layer portion 62 of the third electrode 6 are formed. More specifically, first, a base conductor layer (film thickness: about 0.01 to 1 μm) 7a is formed as a seed layer on the first protective layer 73 by sputtering or electroless plating. Next, a resist mask M5 is disposed over the base conductor layer 7a (FIG. 7A). Next, it is selectively formed on the exposed portion of the first protective layer 73 and the exposed portions of the first upper electrodes 51A and 51B and the upper layer portion 62, and the seed layer not covered with the resist mask M5 is exposed. Then, electroplating is performed to form a second upper electrode electroplating conductor layers 52A and 52B and an upper layer electroplating conductor layer 62 to a desired thickness, and then a resist mask. By removing M5 and the underlying conductor layer 7a outside the electroplated conductor layer, the second upper electrode conductor layers 52A and 52B and the upper layer conductor layer 62 are obtained (FIG. 7B). In FIG. 7B, the conductor layer for the second upper electrode is shown with the same sign as the second electrodes 52A and 52B, and the conductor layer for the upper layer part is shown with the same sign as the upper layer part 62. .

(Second protective layer formation)
Next, the second protective layer 74 is formed so as to cover the end portions of the second upper electrodes 52 </ b> A and 52 </ b> B, the upper surface and side surfaces of the upper layer portion 62, and the upper surface of the first protective layer 73. More specifically, for example, in an uncured photo-curing resin, and then a metal mask M6 is placed on a portion where the second protective layer 74 is not formed (FIG. 8A), By performing patterning by photolithography, portions (openings 71 and 72) connected to the terminal electrodes 8A and 8B on the upper surfaces of the second upper electrodes 52A and 52B are exposed without being covered by the second protective layer 74. (FIG. 8B).

(Terminal electrode formation)
Next, terminal electrodes 8A and 8B formed on the upper surface of the second protective layer 74 and connected to the second upper electrodes 52A and 52B are formed. More specifically, the base conductive layer 8a is formed as a seed layer on the upper surface of the second protective layer 74 by sputtering or electroless plating. Next, a resist mask M7 is disposed over the seed layer (FIG. 9A). Next, selective electroplating is performed on the second protective layer 74 and the exposed portions of the second upper electrodes 52A and 52B, and the portions where the seed layer not covered with the resist mask is exposed. Then, electroplating conductor layers 8A and 8B for terminal electrode formation are formed by electrodeposition until a desired thickness is obtained, and then the resist mask and the seed layer 8a outside the electroplating conductor layer are removed to thereby form the terminal electrode layer. Conductive layers 8A and 8B (precursors of terminal electrodes 8A and 8B) are obtained (FIG. 9B). In FIG. 9B, the terminal electrode conductor layer is indicated by the same reference numerals as the terminal electrodes 8A and 8B.

  Thereafter, for example, after a protective layer for attaching the identification number of the capacitor 1 is formed between the terminal electrodes 8A and 8B in the same layer as the terminal electrodes 8A and 8B (not shown), for example, The substrate 2 is cut (diced) at a predetermined position between the capacitors 1 to be separated into pieces, thereby obtaining the capacitor 1 shown in FIG.

  In the manufacturing process of such a capacitor 1, by forming the third electrode 6 together with the upper electrodes 5A and 5B, as described above, the interval of only the lower electrode 3 having a step can be narrowed. The flatness of the protective layer can be ensured.

  In addition, the third electrode (laminated portion) 6 is divided into the lower layer portion 61 and the upper layer portion 62, so that the first protective layer 73 is formed in the gap between the upper electrode 5A (5B) and the third electrode 6. And since the 2nd protective layer 74 can be embedded in steps, planarization of a protective layer can further be aimed at. That is, for example, if the third electrode is formed before the formation of the protective layer, there is a large step between the third electrode and the upper electrode, and there is a risk of insufficient filling (bubbles) of the protective layer. If the third electrode is formed after the formation, the protective layer is thick and it may be difficult to form the opening. However, the manufacturing process of the capacitor 1 of the present embodiment has these problems. Therefore, the protective layer can be flattened. In addition, as described above, the third electrode 6 is formed simultaneously with the upper electrodes 5A and 5B, so that the manufacturing process is not complicated, and the cost is lower than when only the third electrode 6 is separately formed. It is advantageous.

  Furthermore, with respect to the third electrode 6, by forming the lower layer portion 61, the first protective layer 73, the upper layer portion 62, and the second protective layer 74 in a stepwise manner, the vertical sectional shape of the upper layer portion 62 is changed to a T-shape. It is possible to increase the interface area where the third electrode 6 and the protective layer 7 are in contact with each other. Thereby, peeling between the third electrode 6 and the protective layer 7 can be prevented. And the shape part of the lower end part of the upper layer part of the 3rd electrode 6 plays a role as an anchor, and prevents peeling between the 3rd electrode 6 and the protective layer 7 further.

<Modification>
In addition, as above-mentioned, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the limit which does not change the summary. For example, the capacitor 1 has a structure in which two capacitors are connected in series. However, at least two or more structures in which two capacitors are connected in series can be arranged in one element. For example, as shown in FIG. 10, by arranging four upper electrodes and terminal electrodes in parallel, it is possible to make a structure in which two series capacitors are juxtaposed in one element. FIG. 10 includes upper electrodes 5C, 5D, 5E, 5F and terminal electrodes 8C, 8D, 8E, 8F on the upper electrodes, and a third electrode 6 ′ (protrusion) between the upper electrodes. ) Is shown as an example. Of the four terminal electrodes, a pair of two locations (for example, the terminal electrodes 8C and 8D in FIG. 10) are selected and connected to an external circuit, and the other pair of two locations (for example, the terminal electrodes 8E and 8F in FIG. 10). Can be connected to another external circuit to function as an element in which two series capacitors are juxtaposed. Moreover, when the areas of the upper electrodes 5C, 5D, 5E, and 5F are different, the capacitance value of the series capacitor can be changed by a combination of a pair of two terminal electrodes, so a desired capacitance value can be selected from a plurality of capacitance values. Can be used. Thus, by forming a plurality of series capacitors in one element, the mounting area of an electronic component package, an electronic component module, an electronic device, or the like can be reduced.

  In the capacitor 1 shown in FIG. 2, the case where the third electrode 6 is substantially the same as the height of the adjacent upper electrode is exemplified. Instead, for example, as shown in FIG. 6 ″ (protrusion) may be further laminated to the height of the terminal electrode, and a protective layer 7 ′ may be formed thereon. By adopting such a configuration, the height of the protective layer 7 'positioned between the terminal electrodes becomes higher than the height of each terminal electrode, so that an impact load is applied when the thin film capacitor is mounted on an electronic component (when mounted). Can be relaxed and / or dispersed. In addition, a barrier is defined between the terminal electrodes, and solder bridges can be prevented. In addition, the third electrodes 6, 6 ′, 6 ″ may be formed integrally or separately (for example, as a laminated body).

  As described above, according to the thin film capacitor and the method of manufacturing the same of the present invention, it is possible to improve the withstand voltage of the capacitor as a series capacitor and further reduce the resistance value of the electrode between the capacitors. Since the electrical characteristics and functions of capacitors can be sufficiently enhanced, electronic components that use thin film capacitors, and equipment, devices, systems, and various devices that incorporate such electronic components are particularly required to be smaller and have higher performance. Can be used widely and effectively for production, production and the like.

DESCRIPTION OF SYMBOLS 1 ... Capacitor (thin film capacitor), 2 ... Board | substrate, 3 ... Lower electrode (1st electrode), 4 ... Dielectric film, 5A, 5B, 5C, 5D, 5E, 5F ... Upper electrode (2nd electrode), 6, 6 ', 6' '... 3rd electrode (protrusion part), 7, 7' ... protective layer, 8A, 8B, 8C, 8D, 8E, 8F ... terminal electrode, 9 ... bent part, 41 ... opening (Opening).

Claims (7)

A first electrode formed on a substrate;
At least two second electrodes juxtaposed facing each other through the dielectric film and spaced apart from each other;
On the first electrode, a protrusion disposed between each of the at least two second electrodes and protruding upward from the first electrode ;
A protective layer covering at least a part of the dielectric film and the protrusion and having an opening on each of the at least two second electrodes;
The at least two second layers formed on the protective layer and exposed at the openings of the protective layer.
And at least two terminal electrodes electrically connected to at least a portion of each of the two electrodes ,
The protrusion is not (electrically) connected to any of the terminal electrodes
A thin film capacitor characterized by that . The projecting portion has a lower dielectric section than the end on the dielectric film side in a vertical cross section of the projecting portion.
The width of the end on the side far from the body membrane is increased,
The thin film capacitor according to claim 1 . Each of the at least two second electrodes and at least one of the protrusions
One horizontal cross-sectional shape is a shape having a bend,
The thin film capacitor according to claim 1 or 2 . The protrusion is made of the same material as the first electrode.
The thin film capacitor of any one of Claims 1-3 . The protrusion is made of a material having a lower electrical resistivity than the material of the first electrode.
The thin film capacitor of any one of Claims 1-4 . The protrusion is made of the same material as the second electrode.
The thin film capacitor of any one of Claims 1-5 . Forming a first electrode on a substrate;
At least opposed to the first electrode through a dielectric film and spaced apart from each other
Forming two second electrodes; and
On the first electrode, disposed between each of the at least two second electrodes.
And forming a protrusion protruding upward from the first electrode;
Forming a protective layer covering at least a part of the dielectric film and the protrusion and having an opening on each of the at least two second electrodes;
On the protective layer, the at least two second exposed at the openings of the protective layer.
Forming at least two terminal electrodes electrically connected to at least a portion of each of the two electrodes;
A method for manufacturing a thin film capacitor including:

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