JP2009212541A - Variable capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable capacitor which is suitable for suppressing fluctuations in drive voltage characteristics and for achieving high variability of electrostatic capacitance. <P>SOLUTION: This variable capacitor X10 is provided with a capacitor electrode 32 having a counter surface 32a, a movable capacitor electrode layer 13 having a counter surface 13a facing the counter surface 32a, an anchor portion 34 for partially fixing the movable capacitor electrode layer 13 to the capacitor electrode 32, and a dielectric pattern 14 provided on the counter surface 32a or the counter surface 13a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable capacitor capable of changing a capacitance.

  In the technical field of wireless communication devices such as mobile phones, demands for miniaturization of high-frequency circuits or RF circuits are increasing with an increase in the number of components mounted to realize high functions. In order to meet such demands, various parts constituting a circuit are being miniaturized by utilizing MEMS (micro-electromechanical systems) technology. A variable capacitor is known as one of such parts. The variable capacitor is an important component in a variable frequency oscillator, a tuning amplifier, an impedance matching circuit, and the like. A variable capacitor obtained by using the MEMS technology is described in Patent Documents 1 and 2 below, for example.

JP 2004-6588 A JP 2004-127773 A

  A variable capacitor manufactured using MEMS technology generally has a fixed electrode and a movable electrode that face each other. The movable electrode is provided to be movable back and forth with respect to the fixed electrode. In such a variable capacitor, the voltage applied between the fixed electrode and the movable electrode is controlled to change the electrostatic capacity, and the electrostatic attractive force generated between the electrodes is adjusted, whereby the movable electrode is adjusted. Or the gap between the electrodes is adjusted.

  Further, in such a variable capacitor, in order to prevent the movable electrode that can move forward and backward with respect to the fixed electrode from directly contacting the fixed electrode, for example, a dielectric film is formed on the surface of the fixed electrode on the movable electrode side. May be provided (when both electrodes are in direct contact, the electrodes are short-circuited). If there is a variable capacitor where the movable electrode is intentionally brought into contact with the dielectric film on the surface of the fixed electrode in the control of the variable capacitance, the movable electrode may be inadvertently brought into contact with the dielectric film on the surface of the fixed electrode when controlling the capacitance. Some variable capacitors are possible.

  When a voltage is applied between the fixed electrode and the movable electrode, when the movable electrode comes into contact with the dielectric film on the surface of the fixed electrode, an electric charge may move between the movable electrode and the dielectric film. Specifically, when a voltage is applied between the fixed electrode and the movable electrode so that the movable electrode has a positive potential, the movable electrode and the dielectric film on the surface of the fixed electrode come into contact with each other. At the contact interface of the body film, electrons (negative charges) may move from the dielectric film to the movable electrode, and holes (positive charges) may be generated in the dielectric film. When the movable electrode and the dielectric film on the surface of the fixed electrode come into contact with each other in a state where a voltage is applied between the fixed electrode and the movable electrode so that the fixed electrode has a positive potential, the contact interface between the movable electrode and the dielectric film In some cases, electrons (negative charges) move from the movable electrode to the dielectric film. Therefore, when the contact between the movable electrode and the dielectric film on the surface of the fixed electrode is repeated, the dielectric film tends to be significantly charged due to the charge transfer.

  Even if the voltage applied between the movable electrode and the fixed electrode is the same, the magnitude of the net electric field formed between the electrodes of the variable capacitor varies depending on whether or not the dielectric film is charged. Therefore, the minimum drive voltage that needs to be applied between the electrodes in order to start the operation of the movable electrode from its initial position varies. In addition, the relationship between the capacitance in driving the variable capacitor or its movable electrode and the drive voltage (the voltage to be applied between the electrodes in order to obtain a predetermined capacitance or interelectrode gap) also indicates whether the dielectric film is charged. And will vary depending on the degree. Thus, the drive voltage characteristics vary depending on whether or not the dielectric film is charged. Even if a dielectric film is provided on the surface of the movable electrode in place of the dielectric film on the surface of the fixed electrode or together with the dielectric film on the surface of the fixed electrode, Depending on the presence or absence and degree of charge of the film, the drive voltage characteristics can vary. In the conventional variable capacitor of which the capacitance is controlled by controlling the gap between the electrodes, the degree of fluctuation of the drive voltage characteristic is relatively large. In addition, the capacitance of the variable capacitor is often required to realize a large variable rate.

  The present invention has been conceived under the circumstances as described above, and provides a variable capacitor suitable for suppressing fluctuations in drive voltage characteristics and suitable for realizing a large variable rate of capacitance. The purpose is to do.

  The variable capacitor provided by the first aspect of the present invention has a capacitor electrode having a first facing surface, a second facing surface facing the first facing surface, and on the capacitor electrode side or the capacitor electrode. A movable capacitor electrode film having a portion that is curved so as to protrude to the opposite side, and a dielectric pattern provided on the first opposing surface or the second opposing surface. The dielectric pattern is formed by patterning on the first or second facing surface, and includes, for example, a plurality of dielectric islands spaced apart from each other on the first or second facing surface. The total length of the contour of the dielectric pattern on the first or second opposing surface per unit area of the dielectric pattern is, for example, a rectangular dielectric film over the entire first or second opposing surface. The total length of the contour of the dielectric film when provided is larger than the length per unit area of the dielectric film. That is, the overall length of the contour of the dielectric pattern on the first or second facing surface is relatively long. Such a dielectric pattern is for preventing a short-circuit between the capacitor electrode and the movable capacitor electrode film in the present variable capacitor, and a pattern shape (for example, a dielectric) capable of exhibiting a short-circuit prevention function. A pattern shape that does not expose the first or second opposing surface provided with the pattern excessively wide).

  Since the movable capacitor electrode film of the present variable capacitor is curved as described above, no voltage is applied between the capacitor electrode and the movable capacitor electrode film, and both electrodes are in the initial position (first state). The distance between the first facing surface of the capacitor electrode and the second facing surface of the movable capacitor electrode film is not uniform across the entire facing surface. In such an initial state, the gap between the capacitor electrode or the first opposing surface and the movable capacitor electrode film or the second opposing surface has the maximum volume.

  In this variable capacitor, when a voltage higher than a predetermined value is applied between the electrodes, the first opposing surface of the capacitor electrode and the second opposing surface of the movable capacitor electrode film are brought into contact with each other by the action of electrostatic attraction generated between the electrodes. Alternatively, the closest state (second state) can be achieved via the dielectric pattern on the second facing surface. At this time, the dielectric pattern prevents the capacitor electrode and the movable capacitor electrode film from coming into direct contact. In this state, the gap between the capacitor electrode or the first opposing surface and the movable capacitor electrode film or the second opposing surface has a minimum volume.

  When the voltage applied between the electrodes of the variable capacitor is gradually increased from the first state to the second state, the movable capacitor electrode film having a curved structure is drawn into the capacitor electrode, The movable capacitor electrode film partially contacts with the dielectric pattern (that is, a part of the capacitor electrode and a part of the movable capacitor electrode film come closest to each other through the dielectric pattern). In the capacitor electrode and the movable capacitor electrode film, the distance between the electrodes sequentially reaches the minimum from the vicinity of the partial contact portion, and finally the first opposing surface of the capacitor electrode and the movable capacitor electrode film The distance between the electrodes is minimized over the entire distance from the second facing surface. Thus, in the present variable capacitor, the gap between the first state where the gap volume between the electrodes is maximum and the second state where the gap volume is minimum are adjusted by adjusting the drive voltage applied between the electrodes. The volume can be continuously changed greatly. Therefore, according to the present variable capacitor, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In addition, the dielectric pattern provided on the first or second opposing surface in the present variable capacitor tends to be difficult to be charged. When the dielectric film provided on the surface of the conductor is charged by bringing a conductor member or the like into contact with the dielectric film under a predetermined condition (that is, the dielectric film is subjected to so-called charge transfer from the outside to the dielectric film). When the film is charged), the longer the length of the dielectric film contour on the conductor surface per unit area of the dielectric film, the more the degree of charging tends to be reduced. The inventors have found. When the dielectric film is charged by so-called charge transfer, charges (electrons, holes) are unevenly distributed in the vicinity of the exposed surface of the dielectric film, so that the total length of the contour of the dielectric film per unit area of the dielectric film It seems that the greater the length, the more charge escapes from the vicinity of the exposed surface of the dielectric film to the conductor surface in contact with the exposed surface. This point is considered as the reason for the tendency of charge relaxation.

  In this variable capacitor, as described above, the total length of the contour of the dielectric pattern having a predetermined pattern shape on the first or second facing surface is relatively long (that is, the total length of the contour of the dielectric pattern is Since the length of the dielectric pattern per unit area is relatively large), the electric charge easily escapes from the dielectric pattern to the first or second opposing surface. Therefore, in this variable capacitor, charging of the dielectric pattern due to so-called charge transfer is suppressed. Therefore, in this variable capacitor, the fluctuation of the minimum drive voltage that needs to be applied between the movable capacitor electrode film and the capacitor electrode in order to start the operation from the initial position of the movable capacitor electrode film is suppressed, It is also possible to suppress fluctuations in the relationship between the capacitance and driving voltage (voltage to be applied between the electrodes in order to obtain a predetermined capacitance or interelectrode gap volume) in driving the variable capacitor or movable capacitor electrode film. Is done. Thus, in this variable capacitor, fluctuations in drive voltage characteristics are suppressed.

  As described above, the variable capacitor according to the first aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the second aspect of the present invention includes a capacitor electrode having a first facing surface, a movable capacitor electrode film having a second facing surface facing the first facing surface, and movable with respect to the capacitor electrode. An anchor portion for partially fixing the capacitor electrode film and a dielectric pattern provided on the first opposing surface or the second opposing surface are provided. This dielectric pattern is for preventing a short-circuit between the capacitor electrode and the movable capacitor electrode film, as in the variable capacitor dielectric pattern according to the first aspect, and exhibits a short-circuit prevention function. It has a pattern shape that can be formed, and the overall length of the contour is relatively long.

  In this variable capacitor, when no voltage is applied between the capacitor electrode and the movable capacitor electrode film and both electrodes are in the initial position (first state), the capacitor electrode or the first opposing surface, and the movable capacitor electrode film The gap between the second opposing surface has the maximum volume.

  In this variable capacitor, when a predetermined voltage or higher is applied between the electrodes, a part of the capacitor electrode on the first facing surface (for example, most of the region) and the movable capacitor are caused by the action of electrostatic attraction generated between the electrodes. A partial region (for example, most region) of the second opposing surface of the electrode film is brought into the closest state (second state) via the dielectric pattern on the first or second opposing surface. (The portions fixed to each other by the anchor portion on the capacitor electrode or the first opposing surface and the movable capacitor electrode film or the second corresponding surface are not close to each other). At this time, the dielectric pattern prevents the capacitor electrode and the movable capacitor electrode film from coming into direct contact. In this state, the gap between the capacitor electrode or the first opposing surface and the movable capacitor electrode film or the second opposing surface has a minimum volume.

  When the voltage applied between the electrodes of the variable capacitor is gradually increased from the first state to the second state, the portion of the movable capacitor electrode film fixed to the capacitor electrode by the anchor portion (fixed) The movable capacitor electrode film is drawn into the capacitor electrode (the amount or distance by which the movable capacitor electrode film is drawn into the capacitor electrode is not uniform over the entire movable capacitor electrode film). The electrode film is in partial contact with the dielectric pattern, and in the capacitor electrode and the movable capacitor electrode film, the distance between the electrodes sequentially reaches the minimum in order from the vicinity of the partial contact position, and finally Include a partial area (for example, most area) of the first opposing surface of the capacitor electrode and a movable capacitor. The distance between the electrodes is minimized throughout between the partial region of the second opposing surface of the data electrode film (e.g., most of the region). Thus, in this variable capacitor, the gap volume can be continuously changed greatly between the first state where the gap volume between the electrodes is maximum and the second state where the gap volume is minimum. Therefore, according to the present variable capacitor, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In the variable capacitor, as described above, the total length of the contour of the dielectric pattern having a predetermined pattern shape on the first or second opposing surface is relatively long (that is, the total length of the contour of the dielectric pattern). Therefore, the length of the dielectric pattern per unit area is relatively large), so that the charge easily escapes from the dielectric pattern to the first or second opposing surface. Therefore, in this variable capacitor, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor according to the first aspect.

  As described above, the variable capacitor according to the second aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  In addition, in this variable capacitor, since the capacitor electrode and the movable capacitor electrode film are partially connected or connected by an anchor portion, each electrode caused by a temperature change, both when not driven and when driven. Since an unintentional shape change or curvature of the movable capacitor electrode film (especially the movable capacitor electrode film) is suppressed, fluctuations in the gap volume between the electrodes due to temperature changes are suppressed. Therefore, this variable capacitor is suitable for suppressing the capacitance fluctuation caused by the temperature change. Such technical advantages are also applicable to the variable capacitors according to the following fourth, sixth, and eighth aspects.

  In the variable capacitor according to the first and second aspects of the present invention, the C (capacitance) -V (driving voltage) characteristics can be adjusted by adjusting the shape and / or density of the dielectric pattern. As described above, the dielectric pattern is composed of, for example, a plurality of dielectric islands. In such a dielectric pattern, for example, a CV characteristic is adjusted by providing a portion that changes from a dense portion to a rough portion. can do

  The variable capacitor according to the first and second aspects of the present invention preferably includes a conductor layer on the dielectric pattern. Alternatively, the variable capacitor according to the first and second side surfaces may include a dielectric pattern on the first opposing surface or the second opposing surface where the dielectric pattern is not provided. The dielectric pattern is preferably composed of a plurality of dielectric islands. So-called charge transfer tends to occur less easily between conductors and between dielectrics than between conductors.

  The variable capacitor provided by the third aspect of the present invention has a capacitor electrode having a first facing surface, a second facing surface facing the first facing surface, and on the capacitor electrode side or the capacitor electrode. A movable capacitor electrode film having a portion that is curved so as to protrude to the opposite side, a dielectric film provided on the first opposing surface or the second opposing surface, and a dielectric film are provided And a conductor pattern provided on the first opposing surface or the second opposing surface. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern is a pattern formed on the first or second facing surface, and includes, for example, a plurality of conductor islands spaced apart from each other on the first or second facing surface. The area of the surface on the dielectric film side in such a conductor pattern is smaller than the area of the first or second facing surface.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the first aspect, and therefore, similar to the variable capacitor according to the first aspect, a large variable amount or A variable rate can be realized.

  In the present variable capacitor, the first or second opposing surface in a state (second state) where the distance between the electrodes is minimized over the entire area between the first opposing surface of the capacitor electrode and the second opposing surface of the movable capacitor electrode film. The upper conductor pattern is in direct contact with the dielectric film on the second or first opposing surface. The above-described configuration in which the area of the surface on the dielectric film side in the conductor pattern is smaller than the area of the first or second facing surface is, for example, that the conductor member contacts the dielectric film in such a second state. This contributes to suppression of charge transfer that may occur. Therefore, in this variable capacitor, charging of the dielectric film due to so-called charge transfer is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  As described above, the variable capacitor according to the third aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the fourth aspect of the present invention includes a capacitor electrode having a first facing surface, a movable capacitor electrode film having a second facing surface facing the first facing surface, and the first facing surface or A dielectric film provided on the second facing surface, an anchor portion for partially fixing the movable capacitor electrode film to the capacitor electrode, and the first facing surface or the second surface not provided with the dielectric film. And a conductor pattern provided on the facing surface. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern is a pattern formed on the first or second facing surface. The area of the surface on the dielectric film side in such a conductor pattern is smaller than the area of the first or second facing surface.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the second aspect, and therefore, similar to the variable capacitor according to the second aspect, a large variable amount or A variable rate can be realized.

  In the present variable capacitor, a part of the first facing surface of the capacitor electrode (for example, most region) and a part of the second facing surface of the movable capacitor electrode film (for example, most of the region) are first. Alternatively, in the state closest to the dielectric film on the second opposing surface and the conductor pattern (second state), the conductor pattern on the first or second opposing surface is the dielectric on the second or first opposing surface. Direct contact with body membranes. Therefore, in this variable capacitor, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor according to the third aspect.

  As described above, the variable capacitor according to the fourth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the fifth aspect of the present invention has a capacitor electrode having a first facing surface, a second facing surface facing the first facing surface, and on the capacitor electrode side or the capacitor electrode. A movable capacitor electrode film having a portion curved so as to protrude to the opposite side, a dielectric film provided on the first opposing surface or the second opposing surface, and provided on the dielectric film A conductor pattern. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern is a pattern formed on a dielectric film, and includes, for example, a plurality of conductor islands spaced apart from each other on the dielectric film. The area occupied by such a conductor pattern on the dielectric film is smaller than the area of the dielectric film itself.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the first aspect, and therefore, similar to the variable capacitor according to the first aspect, a large variable amount or A variable rate can be realized.

  In this variable capacitor, the conductor pattern on the dielectric film in a state (second state) in which the distance between the electrodes is minimized over the entire area between the first opposing surface of the capacitor electrode and the second opposing surface of the movable capacitor electrode film. Directly contacts the capacitor electrode (first opposing surface) or the movable capacitor electrode film (second opposing surface). When the conductors contact each other, so-called charge transfer tends not to occur. In addition, the above-described configuration in which the area of the conductor pattern is smaller than the area of the dielectric film occurs, for example, due to the contact between the capacitor electrode or the movable capacitor electrode film and the conductor pattern in such a second state. Contributes to suppressing the charge transfer obtained. Therefore, in this variable capacitor, the amount of charge transfer from the conductor pattern to the dielectric film is suppressed. Therefore, in this variable capacitor, charging of the dielectric film is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  As described above, the variable capacitor according to the fifth aspect of the present invention is suitable for suppressing fluctuations in the drive voltage characteristics and is suitable for realizing a large variable rate with respect to the capacitance.

  The variable capacitor provided by the sixth aspect of the present invention includes a capacitor electrode having a first facing surface, a movable capacitor electrode film having a second facing surface facing the first facing surface, and movable with respect to the capacitor electrode. An anchor for partially fixing the capacitor electrode film, a dielectric film provided on the first opposing surface or the second opposing surface, and a conductor pattern provided on the dielectric film are provided. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern is a pattern formed on a dielectric film. The area occupied by such a conductor pattern on the dielectric film is smaller than the area of the dielectric film itself.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the second aspect, and therefore, similar to the variable capacitor according to the second aspect, a large variable amount or A variable rate can be realized.

  In the present variable capacitor, a part of the first facing surface of the capacitor electrode (for example, most region) and a part of the second facing surface of the movable capacitor electrode film (for example, most of the region) are first. Alternatively, in the state closest to the dielectric film and the conductor pattern on the second opposing surface (second state), the conductor pattern having a small area is movable on the dielectric film as a capacitor electrode (first opposing surface) or movable. The capacitor electrode film (second facing surface) is in direct contact. Therefore, in this variable capacitor, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor according to the fifth aspect.

  Thus, the variable capacitor according to the sixth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the 7th side surface of this invention has a capacitor electrode which has a 1st opposing surface, and a 2nd opposing surface which opposes a 1st opposing surface, and is on the capacitor electrode side or a capacitor electrode On the side of the movable capacitor electrode film, the movable capacitor electrode film having a portion curved so as to protrude to the opposite side, a dielectric film provided on the first facing surface or the second facing surface, and And a conductive pattern embedded in a dielectric film while being exposed. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern has a predetermined pattern shape, and has, for example, a plurality of openings for partially exposing the dielectric film on the counter electrode side.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the first aspect, and therefore, similar to the variable capacitor according to the first aspect, a large variable amount or A variable rate can be realized. In this variable capacitor, even if charges are unevenly distributed on the exposed surface of the dielectric film due to so-called charge transfer, the charges easily escape to the conductor pattern embedded in the dielectric film. Therefore, in this variable capacitor, charging of the dielectric film is suppressed, and fluctuations in drive voltage characteristics are suppressed. Thus, the variable capacitor according to the seventh aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the eighth aspect of the present invention includes a capacitor electrode having a first facing surface, a movable capacitor electrode film having a second facing surface facing the first facing surface, and movable with respect to the capacitor electrode. An anchor for partially fixing the capacitor electrode film, a dielectric film provided on the first facing surface or the second facing surface, and embedded in the dielectric film while being exposed to the movable capacitor electrode film side And a formed conductor pattern. The dielectric film is for preventing a short circuit between the capacitor electrode and the movable capacitor electrode film in the variable capacitor. The conductor pattern is a pattern formed on the dielectric film, and has, for example, a plurality of openings for partially exposing the dielectric film on the counter electrode side.

  The variable capacitor can be driven in a manner similar to that described above with respect to the variable capacitor according to the second aspect, and therefore, similar to the variable capacitor according to the second aspect, a large variable amount or A variable rate can be realized. In this variable capacitor, even if charges are unevenly distributed on the exposed surface of the dielectric film due to so-called charge transfer, the charges easily escape to the conductor pattern embedded in the dielectric film. Therefore, in this variable capacitor, charging of the dielectric film is suppressed, and fluctuations in drive voltage characteristics are suppressed. Thus, the variable capacitor according to the eighth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  In the seventh and eighth aspects of the present invention, preferably, the conductor pattern is a conductor film having a plurality of openings. In this case, preferably, the surface of the dielectric film on the side of the movable capacitor electrode film is flush with the surface of the conductor pattern on the side of the movable capacitor electrode film. Alternatively, the surface of the conductive pattern on the movable capacitor electrode film side may be retracted closer to the capacitor electrode side than the surface of the dielectric film on the movable capacitor electrode film side. Alternatively, the surface of the dielectric film on the side of the movable capacitor electrode film may be retracted closer to the capacitor electrode side than the surface of the conductive pattern on the side of the movable capacitor electrode film.

  The variable capacitor according to the first, third, fifth, and seventh aspects of the present invention preferably includes an anchor portion that partially connects the capacitor electrode and the movable capacitor electrode film. Such a configuration is suitable for suppressing capacitance fluctuations caused by temperature changes.

  In a preferred embodiment of the first to eighth aspects of the present invention, the capacitor electrode is a fixed electrode. In this case, it is preferable that the first facing surface of the fixed electrode has a region curved so as to protrude to the movable capacitor electrode film side or the side opposite to the capacitor electrode.

  In another preferred embodiment of the first to eighth aspects of the present invention, the capacitor electrode is a movable capacitor electrode film. In this case, the movable capacitor electrode film preferably has a portion curved so as to protrude toward the other movable capacitor electrode film or toward the opposite side of the movable capacitor electrode film.

  The variable capacitor provided by the ninth aspect of the present invention includes a movable capacitor electrode film having a first facing surface, and facing the first facing surface and facing the movable capacitor electrode film or opposite to the movable capacitor electrode film. A fixed capacitor electrode having a second opposing surface having a region curved so as to protrude toward the first side, and a dielectric pattern provided on the first opposing surface or the second opposing surface. Like the dielectric pattern of the variable capacitor according to the first aspect, this dielectric pattern is for preventing a short circuit between the electrodes and has a pattern shape capable of exhibiting a short circuit preventing function. And the overall length of the contour is relatively long.

  The variable capacitor can be driven in a manner substantially similar to that described above with respect to the variable capacitor according to the first aspect, and therefore has a large capacitance as with the variable capacitor according to the first aspect. Variable amount or variable rate can be realized.

  In this variable capacitor, as described above, the total length of the contour of the dielectric pattern having a predetermined pattern shape on the first or second facing surface is relatively long (that is, the total length of the contour of the dielectric pattern is Since the length of the dielectric pattern per unit area is relatively large), the charge easily escapes from the dielectric pattern to the first or second opposing surface, and the dielectric pattern is charged due to so-called charge transfer. Is suppressed. Therefore, in this variable capacitor, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor according to the first aspect.

  Thus, the variable capacitor according to the ninth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the tenth aspect of the present invention includes a movable capacitor electrode film having a first facing surface, and facing the first facing surface and on the side of the movable capacitor electrode film or opposite to the movable capacitor electrode film. A fixed capacitor electrode having a second facing surface having a region curved so as to protrude toward the side, a dielectric film provided on the first facing surface or the second facing surface, and a dielectric film provided A conductor pattern provided on the first facing surface or the second facing surface that is not provided. The dielectric film is for preventing a short circuit between the movable capacitor electrode film and the fixed capacitor electrode in the variable capacitor. The conductor pattern is a pattern formed on the first or second facing surface. The area of the surface on the dielectric film side in such a conductor pattern is smaller than the area of the first or second facing surface.

  The variable capacitor can be driven in a manner substantially similar to that described above with respect to the variable capacitor according to the first aspect, and therefore has a large capacitance as with the variable capacitor according to the first aspect. Variable amount or variable rate can be realized.

  In the present variable capacitor, the first or second facing in the state (second state) in which the interelectrode distance is minimized over the entire area between the first facing surface of the movable capacitor electrode film and the second facing surface of the fixed capacitor electrode. The conductor pattern on the surface is in direct contact with the dielectric film on the second or first opposing surface. The above-described configuration in which the area of the surface on the dielectric film side in the conductor pattern is smaller than the area of the first or second facing surface is, for example, that the conductor member contacts the dielectric film in such a second state. This contributes to suppression of charge transfer that may occur. Therefore, in this variable capacitor, for the same reason as described above with respect to the variable capacitor according to the third aspect, charging of the dielectric film due to so-called charge transfer is suppressed, and fluctuations in drive voltage characteristics are It is suppressed.

  Thus, the variable capacitor according to the tenth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the eleventh aspect of the present invention includes a movable capacitor electrode film having a first facing surface, and facing the first facing surface and on the side of the movable capacitor electrode film or opposite to the movable capacitor electrode film. A fixed capacitor electrode having a second opposing surface having a region curved so as to protrude toward the side, a dielectric film provided on the first opposing surface or the second opposing surface, and on the dielectric film And a conductor pattern provided. The dielectric film is for preventing a short circuit between the movable capacitor electrode film and the fixed capacitor electrode in the variable capacitor. The conductor pattern is a pattern formed on a dielectric film. The area occupied by such a conductor pattern on the dielectric film is smaller than the area of the dielectric film itself.

  The variable capacitor can be driven in a manner substantially similar to that described above with respect to the variable capacitor according to the first aspect, and therefore has a large capacitance as with the variable capacitor according to the first aspect. Variable amount or variable rate can be realized.

  In this variable capacitor, in a state where the distance between the electrodes is minimized over the entire distance between the first opposing surface of the movable capacitor electrode film and the second opposing surface of the fixed capacitor electrode (second state), A small-area conductor pattern is in direct contact with the movable capacitor electrode film (first opposing surface) or the fixed capacitor electrode (second opposing surface). Therefore, in the present variable capacitor, fluctuations in drive voltage characteristics are suppressed for the same reason as described above for the variable capacitor according to the fifth aspect.

  Thus, the variable capacitor according to the eleventh aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

  The variable capacitor provided by the twelfth aspect of the present invention includes a movable capacitor electrode film having a first facing surface, and a side facing the first facing surface and on the side of the movable capacitor electrode film or on the side opposite to the capacitor electrode. A fixed capacitor electrode having a second facing surface that has a curved region protruding so as to protrude toward the first surface, a dielectric film provided on the first facing surface or the second facing surface, and a movable capacitor electrode film side And a conductive pattern embedded in a dielectric film while being exposed. The dielectric film is for preventing a short circuit between the movable capacitor electrode film and the fixed capacitor electrode in the variable capacitor. The conductor pattern is a pattern formed on the dielectric film, and has, for example, a plurality of openings for partially exposing the dielectric film on the counter electrode side.

  The variable capacitor can be driven in a manner substantially similar to that described above with respect to the variable capacitor according to the first aspect, and therefore has a large capacitance as with the variable capacitor according to the first aspect. Variable amount or variable rate can be realized. In this variable capacitor, even if charges are unevenly distributed on the exposed surface of the dielectric film due to so-called charge transfer, the charges easily escape to the conductor pattern embedded in the dielectric film. Therefore, in this variable capacitor, for the same reason as described above with respect to the variable capacitor according to the seventh aspect, charging of the dielectric film is suppressed, and fluctuations in drive voltage characteristics are suppressed. Thus, the variable capacitor according to the twelfth aspect of the present invention is suitable for suppressing fluctuations in drive voltage characteristics, and is suitable for realizing a large variable rate with respect to capacitance.

1 is a plan view of a variable capacitor according to a first embodiment of the present invention. FIG. 3 is a partially omitted plan view of the variable capacitor according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is a partially enlarged cross-sectional view taken along line IV-IV in FIG. 1. 1 illustrates a driving mode of the variable capacitor illustrated in FIG. 1. FIG. 2 illustrates some steps in the method for manufacturing the variable capacitor illustrated in FIG. 1. The process following FIG. 6 is represented. This represents a variation of the dielectric pattern. It is a fragmentary sectional view of the 1st modification of the variable capacitor shown in FIG. It is a fragmentary sectional view of the 2nd modification of the variable capacitor shown in FIG. It is a fragmentary sectional view of the 3rd modification of the variable capacitor shown in FIG. It is a fragmentary sectional view of the variable capacitor concerning a 2nd embodiment of the present invention. The pattern shape of the conductor pattern in 2nd Embodiment is represented. It is a fragmentary sectional view of the variable capacitor which concerns on the 3rd Embodiment of this invention. The pattern shape of the conductor pattern in 3rd Embodiment is represented. It is a fragmentary sectional view of the variable capacitor which concerns on the 4th Embodiment of this invention. The pattern shape of the conductor pattern embedded in the dielectric film in 4th Embodiment is represented. It is a fragmentary sectional view of the variable capacitor which concerns on the 5th Embodiment of this invention. The pattern shape of the conductor pattern by the side of the movable electrode in 5th Embodiment is represented. It is a fragmentary sectional view of the variable capacitor which concerns on the 6th Embodiment of this invention. The pattern shape of the conductor pattern by the side of the movable electrode in 6th Embodiment is represented. It is a fragmentary sectional view of the variable capacitor concerning a 7th embodiment of the present invention. FIG. 23 shows some steps in the method of manufacturing the variable capacitor shown in FIG. The process following FIG. 23 is represented. The drive mode of the variable capacitor shown in FIG. 22 is represented. It is a top view of the variable capacitor which concerns on the 8th Embodiment of this invention. It is a partially omitted plan view of a variable capacitor according to an eighth embodiment of the present invention. FIG. 27 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. FIG. 27 is a partial enlarged cross-sectional view taken along line XXIX-XXIX in FIG. 26. FIG. 30 illustrates some steps in the method of manufacturing the variable capacitor illustrated in FIG. 29. The process following FIG. 30 is represented. FIG. 27 illustrates a driving mode of the variable capacitor illustrated in FIG. 26. It is a fragmentary sectional view of the variable capacitor which concerns on the 9th Embodiment of this invention. FIG. 34 illustrates a driving mode of the variable capacitor illustrated in FIG. 33. It is a fragmentary sectional view of the variable capacitor which concerns on the 10th Embodiment of this invention. This represents a driving mode of the variable capacitor shown in FIG.

  1 to 4 show a variable capacitor X1 according to the first embodiment of the present invention. FIG. 1 is a plan view of the variable capacitor X1. FIG. 2 is a partially omitted plan view of the variable capacitor X1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a partially enlarged cross-sectional view taken along line IV-IV in FIG. The variable capacitor X1 includes a substrate 11, a fixed electrode 12, a movable electrode 13 (not shown in FIG. 2), and a dielectric pattern 14.

  The substrate 11 is made of, for example, a silicon material. A predetermined wiring pattern (not shown) that is electrically connected to the fixed electrode 12 or the movable electrode 13 is formed on the substrate 11.

The fixed electrode 12 is patterned on the substrate 11 and forms one of a pair of capacitor electrodes in the variable capacitor X1. The movable electrode 13 is erected on the substrate 11 as shown in FIG. 3, and forms the other of the pair of capacitor electrodes in the variable capacitor X1. As shown in FIG. 1, the fixed electrode 12 and the movable electrode 13 intersect and partially face each other, the fixed electrode 12 has a facing surface 12a facing the movable electrode 13, and the movable electrode 13 is It has a facing surface 13 a that faces the fixed electrode 12. The facing area between the fixed electrode 12 or the facing surface 12a and the movable electrode 13 or the facing surface 13a is, for example, 10000 to 40000 μm ² . Further, at least a portion of the movable electrode 13 facing the fixed electrode 12 is curved so as to protrude toward the fixed electrode 12 as shown in FIG. The distance L shown in FIG. 4 between the fixed electrode 12 and the movable electrode 13 is, for example, 0.5 to 2 μm. The thickness of the movable electrode 13 is, for example, 1 to 2 μm. Preferably, one of the fixed electrode 12 and the movable electrode 13 is grounded. The fixed electrode 12 and the movable electrode 13 are made of a conductive material such as aluminum (Al) or copper (Cu).

The dielectric pattern 14 is provided on the facing surface 12a of the fixed electrode 12, and in the present embodiment, the dielectric pattern 14 is composed of a plurality of dielectric islands 14a spaced apart from each other on the facing surface 12a. The total length of the contour of the dielectric pattern 14 per unit area of the dielectric pattern 14 is the contour of the dielectric film when, for example, a rectangular dielectric film is temporarily provided over the entire opposing surface 12a. The total length is larger than the length per unit area of the dielectric film. That is, the total length of the contour of the dielectric pattern 14 on the facing surface 12a is relatively long. Such a dielectric pattern 14 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X1, and has a pattern shape that can exhibit a short-circuit prevention function (for example, facing A pattern shape that does not expose the surface 12a excessively widely). The thickness of the dielectric pattern 14 is, for example, 0.1 to 0.5 μm. Examples of the constituent material of the dielectric pattern 14 include alumina (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), and silicon nitride (SiN _x ).

  In the variable capacitor X1 having such a configuration, an electrostatic attractive force is generated between the fixed electrode 12 and the movable electrode 13 by applying a voltage (drive voltage) between the fixed electrode 12 and the movable electrode 13. By using the electrostatic attractive force, the movable electrode 13 is drawn toward the fixed electrode 12, and as shown in FIG. 5, the fixed electrode 12 or the opposed surface 12a and the movable electrode 13 or the opposed surface 13a The volume of the gap G1 between can be changed. Specifically, it is as follows.

  Since the movable electrode 13 of the variable capacitor X1 is curved as described above, no voltage is applied between the fixed electrode 12 and the movable electrode 13, and both electrodes are in the initial position as shown in FIG. In the (first state), the distance between the opposing surface 12a of the fixed electrode 12 and the opposing surface 13a of the movable electrode 13 is not uniform over the entire area between the opposing surfaces 12a and 13a. In such an initial state, the gap G1 has a maximum volume.

  In the variable capacitor X1, when a voltage higher than a predetermined voltage is applied between the fixed electrode 12 and the movable electrode 13, the fixed electrode 12 (opposing surface 12a) and the movable electrode 13 (opposing surface) are caused by the action of electrostatic attraction generated between the electrodes. 13a) can be brought to the closest state (second state) shown in FIG. At this time, the dielectric pattern 14 prevents the fixed electrode 12 and the movable electrode 13 from coming into direct contact. In this state, the gap G1 has a minimum volume.

  When the driving voltage applied between the electrodes of the variable capacitor X1 is gradually increased until the variable capacitor X1 reaches the second state from the first state, the movable electrode 13 having a curved structure is drawn into the fixed electrode 12, for example, FIG. As shown in FIG. 5B, the fixed electrode 12 and the movable electrode 13 are first brought into partial contact via the dielectric pattern 14 or the dielectric island 14a (that is, a part of the fixed electrode 12). And a part of the movable electrode 13 reach the closest state via the dielectric pattern 14). Subsequently, for example, as shown in FIG. 5C, in the fixed electrode 12 and the movable electrode 13, the distance between the electrodes is sequentially minimized from the vicinity of the partial contact portion. Finally, as shown in FIG. 5D, the inter-electrode distance is minimized over the entire area between the fixed electrode 12 (opposing surface 12a) and the movable electrode 13 (opposing surface 13a).

  As described above, in the variable capacitor X1, by adjusting the drive voltage (for example, 0 to 20 V) applied between the fixed electrode 12 and the movable electrode 13, the first state in which the volume of the gap G1 between the electrodes is maximum is set. The gap volume can be continuously changed greatly between the second state in which the volume of the gap G1 is minimum. Therefore, according to the variable capacitor X1, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In addition, the dielectric pattern 14 provided on the opposing surface 12a in the variable capacitor X1 tends to be difficult to be charged. When the dielectric film provided on the surface of the conductor is charged by bringing a conductor member or the like into contact with the dielectric film under a predetermined condition (that is, the dielectric film is subjected to so-called charge transfer from the outside to the dielectric film). When the film is charged), the longer the length of the dielectric film contour on the conductor surface per unit area of the dielectric film, the more the degree of charging tends to be reduced. The inventors have found. When the dielectric film is charged by so-called charge transfer, charges (electrons, holes) are unevenly distributed in the vicinity of the exposed surface of the dielectric film, so that the total length of the contour of the dielectric film per unit area of the dielectric film It seems that the greater the length, the more charge escapes from the vicinity of the exposed surface of the dielectric film to the conductor surface in contact with the exposed surface. This point is considered as the reason for the tendency of charge relaxation.

  In the variable capacitor X1, as described above, the total length of the contour of the dielectric pattern 14 having a predetermined pattern shape on the opposing surface 12a is relatively long (that is, the dielectric pattern 14 having the total length of the contour of the dielectric pattern 14). The length per unit area of the body pattern 14 is relatively large). For this reason, electric charges easily escape from the dielectric pattern 14 to the facing surface 12a, and charging of the dielectric pattern 14 due to so-called charge transfer is suppressed. Therefore, in the variable capacitor X1, fluctuations in the minimum drive voltage that must be applied between the fixed electrode 12 and the movable electrode 13 in order to start the operation of the movable electrode 13 from its initial position are suppressed, Fluctuations in the relationship between the capacitance and driving voltage (voltage to be applied between the electrodes to obtain a predetermined capacitance or gap volume) in driving the variable capacitor X1 or the movable electrode 13 are also suppressed. Thus, in the variable capacitor X1, fluctuations in the drive voltage characteristics are suppressed.

  6 and 7 show an example of a manufacturing method of the variable capacitor X1 as a change in cross section corresponding to FIG. This method is a method of manufacturing the variable capacitor X1 using so-called MEMS technology.

  In manufacturing the variable capacitor X1, first, the fixed electrode 12 is formed as shown in FIG. For example, after the Al film is formed on the substrate 11 by the sputtering method, the fixed electrode 12 is patterned on the substrate 11 by etching the Al film using a predetermined resist pattern as a mask. Can do.

Next, a dielectric pattern 14 is formed as shown in FIG. For example, after Al ₂ O ₃ is formed on the fixed electrode 12 and the substrate 11 by a sputtering method, the Al ₂ O ₃ film is etched using a predetermined resist pattern as a mask, A dielectric pattern 14 can be formed on the fixed electrode 12.

  Next, a sacrificial film 15 is formed as shown in FIG. The sacrificial film 15 has an opening (not shown) for partially exposing the substrate 11. This opening is for exposing a region of the substrate 11 where the movable electrode 13 is joined. The sacrificial film 15 is made of, for example, a photoresist. In the formation of the sacrificial film 15, for example, a sacrificial film material is formed on the substrate 11 by a sputtering method so as to cover the fixed electrode 12 and the dielectric pattern 14, and then a predetermined resist pattern is formed on the film. Etching is performed using it as a mask.

  Next, the movable electrode 13 is formed as shown in FIG. In the formation of the movable electrode 13, for example, Al is deposited on the sacrificial film 15 and in the above-described opening by sputtering, and then the Al film is etched using a predetermined resist pattern as a mask. Apply.

  Next, as shown in FIG. 7B, the material film 16 is formed on the movable electrode 13. Specifically, a predetermined material is formed on the movable electrode 13 and the sacrificial film 15 by a sputtering method under a predetermined high-temperature condition, and the material film is etched using a predetermined resist pattern as a mask. Apply. The material film 16 is for forming the above-described curved structure in the movable electrode 13 and is made of a material having a higher thermal expansion coefficient than that of the constituent material of the movable electrode 13. As a constituent material of the material film 16, for example, zinc or tin can be used. When the temperature is lowered after this step, a larger contraction force is generated in the material film 16 than in the movable electrode 13.

  Next, the sacrificial film 15 is removed as shown in FIG. Specifically, the sacrificial film 15 is removed by a wet etching method using a predetermined resist stripping solution. When the sacrificial film 15 is removed, the material film 16 contracts more than the movable electrode 13 and partially curves the movable electrode 13. For example, the variable capacitor X1 can be manufactured as described above. The material film 16 which is an example of a means for bending the movable electrode 13 is not shown in FIG.

FIG. 8 shows a variation of the pattern of the dielectric pattern 14 formed on the facing surface 12 a of the fixed electrode 12. By appropriately adjusting the pattern shape, density, and constituent material of the dielectric pattern 14 disposed between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X1, C (capacitance) −V ( Driving voltage) characteristics can be adjusted. Specifically, the maximum capacitance Fmax of the variable capacitor X1 and the capacitance change rate ΔF appearing in the CV characteristic curve are adjusted by adjusting the pattern shape, density, and constituent material of the dielectric pattern 14. Is possible. For example, the capacitance change rate ΔF tends to increase as the density of the dielectric pattern 14 increases. Further, for example, in the above-described variable capacitor X1 having the dielectric pattern 14 composed of the evenly arranged dielectric islands 14a, by gradually increasing the driving voltage, the state described above with reference to FIG. When the state is changed to the state (second state) described above with reference to FIG. 5D, the capacitance may increase in a quadratic function with the increase of the driving voltage. In FIG. 8 (c), for example, the smaller the degree of coarseness in the outer portion where the timing of contact with the movable electrode 13 is slower, the capacitance increase accompanying the increase in the drive voltage becomes relatively gradual, and is linear function-like. Approximate to increase. It is easier to variably control the capacitance when the increase in the capacitance accompanying the increase in the drive voltage is a linear function than when it is a quadratic function.

  FIG. 9 is a cross-sectional view of a first modification of the variable capacitor X1. In the variable capacitor X1, instead of providing the dielectric pattern 14 on the facing surface 12a of the fixed electrode 12, the dielectric pattern 14 may be provided on the facing surface 13a of the movable electrode 13.

  FIG. 10 is a cross-sectional view of a second modification of the variable capacitor X1. In the variable capacitor X1, in addition to providing the dielectric pattern 14 on the opposing surface 12a of the fixed electrode 12, a dielectric pattern 14 'may be provided on the opposing surface 13a of the movable electrode 13. The dielectric patterns 14, 14 'have the same pattern shape and are composed of a plurality of conductor islands 14'a. According to such a configuration, the movable electrode 13 is not in direct contact with the dielectric pattern 14.

  FIG. 11 is a cross-sectional view of a third modification of the variable capacitor X1. In the variable capacitor X1, a conductor layer 17 may be provided on the dielectric pattern. The conductor layer 17 is made of nickel or titanium, for example. According to such a configuration, the movable electrode 13 is not in direct contact with the dielectric pattern 14. Further, the dielectric pattern 14 with the conductor layer 17 may be provided on the opposing surface 13 a of the movable electrode 13 instead of being provided on the opposing surface 12 a of the fixed electrode 12.

  FIG. 12 is a partial cross-sectional view of the variable capacitor X2 according to the second embodiment of the present invention. The variable capacitor X2 includes a substrate 11, a fixed electrode 12, a movable electrode 13 having a curved shape, a dielectric film 21, and a conductor pattern 22. The variable capacitor X2 is different from the variable capacitor X1 in that a dielectric film 21 and a conductor pattern 22 are provided instead of the dielectric pattern 14.

  The dielectric film 21 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X2. The dielectric film 21 is made of, for example, a silicon oxide film. The conductor pattern 22 is formed on the opposing surface 13a of the movable electrode 13, and includes a plurality of conductor islands 22a spaced apart from each other, for example, as shown in FIG. The area of the surface of the conductor pattern 22 on the dielectric film 21 side is smaller than the area of the facing surface 13a. The conductor pattern 22 is made of nickel or titanium, for example.

  The variable capacitor X2 can be driven in the same manner as described above with respect to the variable capacitor X1, and the gap between the first state (initial state) and the gap shown in FIG. The gap volume can be continuously changed greatly between the second state shown in FIG. 12B in which the volume of G2 is minimum. Therefore, according to the variable capacitor X2, similarly to the variable capacitor X1, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In the variable capacitor X2, for example, in the second state shown in FIG. 12B, the conductor pattern 22 on the facing surface 13a of the movable electrode 13 directly contacts the dielectric film 21 on the facing surface 12a of the fixed electrode 12. Contact. The above-described configuration in which the surface area of the conductor pattern 22 on the side of the dielectric film 21 is smaller than the area of the facing surface 13 a suppresses charge transfer that may occur due to the contact of the conductor member with the dielectric film 21. Contribute to Therefore, in the variable capacitor X2, charging of the dielectric film 21 due to so-called charge transfer is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  FIG. 14 is a partial cross-sectional view of a variable capacitor X3 according to the third embodiment of the present invention. The variable capacitor X <b> 3 includes a substrate 11, a fixed electrode 12, a movable electrode 13 having a curved shape, a dielectric film 21, and a conductor pattern 23. The variable capacitor X3 is different from the variable capacitor X1 in that it includes a dielectric film 21 and a conductor pattern 23 instead of the dielectric pattern 14.

  The dielectric film 21 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X3. The conductor pattern 23 is formed by patterning on the dielectric film 21, and includes, for example, a plurality of conductor islands 23a spaced from each other as shown in FIG. The area occupied by the conductor pattern 23 on the dielectric film 21 is smaller than the area of the dielectric film 21 itself. The conductor pattern 23 is made of nickel or titanium, for example.

  The variable capacitor X3 can be driven in the same manner as described above with respect to the variable capacitor X1, and the first state (initial state) and the gap shown in FIG. 14A in which the volume of the gap G3 between the electrodes is maximum. The gap volume can be continuously changed greatly between the second state shown in FIG. 14B where the volume of G3 is the smallest. Therefore, according to the variable capacitor X3, similarly to the variable capacitor X1, a large variable amount or variable rate can be realized with respect to the capacitance.

  In the variable capacitor X3, for example, in the second state shown in FIG. 14B, the conductor pattern 23 on the dielectric film 21 is in direct contact with the movable electrode 13 (opposing surface 13a). When the conductors contact each other, so-called charge transfer tends not to occur. In addition, the above-described configuration in which the area of the conductor pattern 23 is smaller than the area of the dielectric film 21 contributes to suppressing charge transfer that may occur due to the contact between the movable electrode 13 and the conductor pattern 23. Therefore, in the variable capacitor X3, the amount of charge transfer from the conductor pattern 23 to the dielectric film 21 is suppressed. Therefore, in the variable capacitor X3, charging of the dielectric film 21 is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  FIG. 16 is a partial cross-sectional view of a variable capacitor X4 according to the fourth embodiment of the present invention. The variable capacitor X4 includes a substrate 11, a fixed electrode 12, a movable electrode 13 having a curved shape, a dielectric film 24, and a conductor pattern 25. The variable capacitor X4 is different from the variable capacitor X1 in that a dielectric film 24 and a conductor pattern 25 are provided instead of the dielectric pattern 14. The dielectric film 24 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X4. The conductor pattern 25 has a predetermined pattern shape, and has a plurality of openings for partially exposing the dielectric film 24, for example, as shown in FIG. The surface 24a of the dielectric film 24 and the surface 25a of the conductor pattern 25 are flush with each other. The dielectric film 24 is made of alumina, for example. The conductor pattern 25 is made of aluminum, for example.

  The variable capacitor X4 can be driven in the same manner as described above with respect to the variable capacitor X1, and the gap between the first state (initial state) and the gap shown in FIG. The gap volume can be continuously changed greatly between the second state shown in FIG. 16B where the volume of G4 is the smallest. Therefore, according to the variable capacitor X4, similarly to the variable capacitor X1, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In the variable capacitor X4, even if charges are unevenly distributed on the exposed surface of the dielectric film 24 due to so-called charge movement, the charges easily escape to the conductor pattern 25 embedded in the dielectric film 24. Therefore, in the variable capacitor X4, the charging of the dielectric film 24 is suppressed, and the fluctuation of the driving voltage characteristic is suppressed.

  FIG. 18 is a partial cross-sectional view of a variable capacitor X5 according to the fifth embodiment of the present invention. The variable capacitor X5 includes a substrate 11, a fixed electrode 12, a movable electrode 13 having a curved shape, a dielectric film 24, and conductor patterns 25 and 26. The variable capacitor X5 is different from the variable capacitor X1 in that a dielectric film 24 and conductor patterns 25 and 26 are provided instead of the dielectric pattern 14. The dielectric film 24 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X5. The conductor pattern 25 has a predetermined pattern shape and has a plurality of openings for partially exposing the dielectric film 24. In the present embodiment, the surface 25 a of the conductor pattern 25 is retracted closer to the fixed electrode 12 than the surface 24 a of the dielectric film 24. The conductor pattern 26 has the same pattern shape as the conductor pattern 25, and has a plurality of openings as shown in FIG. 19, for example. The conductor pattern 26 is made of nickel or titanium, for example.

  The variable capacitor X5 can be driven in the same manner as described above with respect to the variable capacitor X1, and the first state (initial state) and the gap shown in FIG. 18A in which the volume of the gap G5 between the electrodes is maximum. The gap volume can be changed continuously and greatly between the second state shown in FIG. 18B where the volume of G5 is minimum (in the second state, the dielectric film 24 and the movable electrode 13 And the conductor patterns 25 and 26 are in contact). Therefore, according to the variable capacitor X5, similarly to the variable capacitor X1, it is possible to realize a large variable amount or variable rate for the capacitance.

  In the variable capacitor X5, even if charges are unevenly distributed on the exposed surface of the dielectric film 24 due to so-called charge transfer, the charges easily escape to the conductor pattern 25 embedded in the dielectric film 24. Therefore, in the variable capacitor X5, charging of the dielectric film 24 is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  FIG. 20A is a partial cross-sectional view of a variable capacitor X6 according to the sixth embodiment of the present invention. The variable capacitor X6 includes a substrate 11, a fixed electrode 12, a movable electrode 13 having a curved shape, a dielectric film 24, and conductor patterns 25 and 27. The variable capacitor X5 is different from the variable capacitor X1 in that it includes a dielectric film 24 and conductor patterns 25 and 27 in place of the dielectric pattern 14. The dielectric film 24 is for preventing a short circuit between the fixed electrode 12 and the movable electrode 13 in the variable capacitor X6. The conductor pattern 25 has a predetermined pattern shape and has a plurality of openings for partially exposing the dielectric film 24. In the present embodiment, the surface 24 a of the dielectric film 24 is retracted closer to the fixed electrode 12 than the surface 25 a of the conductor pattern 25. The conductor pattern 27 has a pattern shape corresponding to the opening of the conductor pattern 25, and is composed of a plurality of conductor islands 27a as shown in FIG. The conductor pattern 27 is made of, for example, nickel or titanium.

  The variable capacitor X6 can be driven in the same manner as described above with respect to the variable capacitor X1, and the first state (initial state) and the gap shown in FIG. 20A in which the volume of the gap G6 between the electrodes is maximum. The gap volume can be continuously changed greatly between the second state shown in FIG. 20B in which the volume of G6 is the minimum (in the second state, the dielectric film 24 and the conductor pattern 27 are And the movable electrode 13 and the conductor pattern 25 are in contact). Therefore, according to the variable capacitor X6, as in the variable capacitor X1, a large variable amount or variable rate can be realized for the capacitance.

  In the variable capacitor X6, even if charges are unevenly distributed on the exposed surface of the dielectric film 24 due to so-called charge movement, the charges easily escape to the conductor pattern 25 embedded in the dielectric film 24. Therefore, in the variable capacitor X6, charging of the dielectric film 24 is suppressed, and fluctuations in drive voltage characteristics are suppressed.

  FIG. 22 is a partial cross-sectional view of a variable capacitor X7 according to the seventh embodiment of the present invention. FIG. 22 corresponds to FIG. 4 for the variable capacitor X1. The variable capacitor X7 includes a substrate 11, a fixed electrode 12 having a curved shape, a movable electrode 13 having no curved shape, a dielectric pattern 14, and a hill portion 28. The variable capacitor X7 is different from the variable capacitor X1 in that it has a hill 28, the fixed electrode 12 has a curved shape, and the movable electrode 13 does not have a curved shape.

  23 and 24 show an example of a manufacturing method of the variable capacitor X7. In the manufacture of the variable capacitor X7, first, as shown in FIG. 23A, a resist pattern 28 'is formed at a predetermined location on the substrate 11. Next, through a heat treatment, the resist pattern 28 ′ is deformed as shown in FIG. Next, as shown in FIG. 23C, the fixed electrode 12 and the dielectric pattern 14 are formed. These specific formation methods are the same as those described above with reference to FIGS. 6 (a) and 6 (b). Next, the sacrificial film 15 is formed as shown in FIG. 24A, and then the movable electrode 13 is formed as shown in FIG. These specific formation methods are the same as those described above with reference to FIGS. 6C and 7A. Next, as shown in FIG. 24C, the sacrificial film 15 is removed by wet etching, for example. As described above, the variable capacitor X7 including the fixed electrode 12 having a curved shape can be manufactured.

  Variable capacitor X7 can be driven in a manner similar to that described above with respect to variable capacitor X1. Specifically, as shown in FIG. 25, the volume of the gap G7 between the fixed electrode 12 and the movable electrode 13 is the maximum in the first state (initial state) shown in FIG. The gap volume can be continuously changed greatly between the minimum state and the second state shown in FIG. Therefore, according to the variable capacitor X7, similarly to the variable capacitor X1, a large variable amount or variable rate can be realized with respect to the capacitance.

  In the variable capacitor X7, as in the variable capacitor X1, the total length of the contour of the dielectric pattern 14 having a predetermined pattern shape on the facing surface 12a of the fixed electrode 12 is relatively long (that is, the dielectric pattern 14 The length per unit area of the dielectric pattern 14 is relatively large). For this reason, electric charges easily escape from the dielectric pattern 14 to the facing surface 12a, and charging of the dielectric pattern 14 due to so-called charge transfer is suppressed. Therefore, in the variable capacitor X7, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor X1.

  In the variable capacitor X7, as described above for the variable capacitor X1, instead of providing the dielectric pattern 14 on the facing surface 12a of the fixed electrode 12, the dielectric pattern 14 shown in FIG. You may provide on the opposing surface 13a. In the variable capacitor X7, in the same manner as described above for the variable capacitor X1, in addition to providing the dielectric pattern 14 on the facing surface 12a of the fixed electrode 12, the dielectric pattern 14 ′ shown in FIG. You may provide on the opposing surface 13a. In the variable capacitor X7, the conductor layer 17 shown in FIG. 11 may be provided on the dielectric pattern 14 in the same manner as described above for the variable capacitor X1.

  In the variable capacitor X 7, the dielectric film 21 described above with respect to the variable capacitor X 2 shown in FIG. 12 is provided on the opposing surface 12 a of the fixed electrode 12 or the opposing surface 13 a of the movable electrode 13 without providing the dielectric pattern 14. In addition, the conductor pattern 22 described above with respect to the variable capacitor X2 may be provided on the opposing surface 12a or the opposing surface 13a where the dielectric film 21 is not provided. In the variable capacitor X7, without providing the dielectric pattern 14, the dielectric film 21 described above with respect to the variable capacitor X3 shown in FIG. 14 and the conductor pattern 23 thereon are provided on the opposing surface 12a or the opposing surface 13a. Also good. In the variable capacitor X7, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X4 shown in FIG. 16 may be provided on the opposing surface 12a or the opposing surface 13a without providing the dielectric pattern 14. In the variable capacitor X7, without providing the dielectric pattern 14, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X5 shown in FIG. 18 are provided on the opposing surface 12a or the opposing surface 13a, and the variable capacitor The conductor pattern 26 described above with respect to X5 may be provided on the opposing surface 12a or the opposing surface 13a where the dielectric film 24 and the conductor pattern 25 are not provided. In the variable capacitor X7, without providing the dielectric pattern 14, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X6 shown in FIG. 20 are provided on the facing surface 12a or the facing surface 13a, and the variable capacitor The conductor pattern 27 described above with respect to X6 may be provided on the opposing surface 12a or the opposing surface 13a where the dielectric film 24 and the conductor pattern 25 are not provided.

  26 to 29 show a variable capacitor X8 according to an eighth embodiment of the present invention. FIG. 26 is a plan view of the variable capacitor X8. FIG. 27 is a partially omitted plan view of the variable capacitor X8. 28 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 29 is a partially enlarged cross-sectional view taken along line XXIX-XXIX in FIG.

  The variable capacitor X8 includes a substrate 31, a movable electrode 32, a movable electrode 13 (not shown in FIG. 27), and a dielectric pattern 14. The variable capacitor X8 is different from the variable capacitor X1 in that a substrate 31 and a movable electrode 32 are provided instead of the substrate 11 and the fixed electrode 12.

  The substrate 31 has a recess 31a and is made of, for example, a silicon material. A predetermined wiring pattern (not shown) that is electrically connected to the movable electrode 32 or the movable electrode 13 is formed on the substrate 31.

The movable electrode 32 is provided so that both ends are joined to the substrate 31 and extend above the recess 31a, and forms one of the pair of capacitor electrodes in the variable capacitor X8. The movable electrode 13 is erected on the substrate 31 as shown in FIG. 28, and forms the other of the pair of capacitor electrodes in the variable capacitor X8. The movable electrode 32 and the movable electrode 13 cross and partially face each other as shown in FIG. 26. The movable electrode 32 has a facing surface 32a that faces the movable electrode 13. It has a facing surface 13 a that faces the movable electrode 32. The facing area between the movable electrode 32 or the opposed surface 32a and the movable electrode 13 or the opposed surface 13a is, for example, 10000 to 40000 μm ² . Further, at least a portion of the movable electrode 13 that faces the movable electrode 32 is curved so as to protrude toward the movable electrode 32 as shown in FIG. The distance L shown in FIG. 29 between the movable electrode 32 and the movable electrode 13 is, for example, 0.5 to 2 μm. The thickness of the movable electrode 32 is, for example, 1 to 2 μm. Preferably, one of the movable electrode 32 and the movable electrode 13 is grounded. The movable electrode 32 and the movable electrode 13 are made of a conductive material such as aluminum (Al) or copper (Cu).

  30 and 31 show an example of a method for manufacturing the variable capacitor X8 as a change in cross section corresponding to FIG. In the manufacture of the variable capacitor X8, first, as shown in FIG. 30A, a substrate 31 having a recess 31a is prepared. For example, the substrate 31 having the recesses 31a can be produced by performing anisotropic dry etching on a predetermined silicon substrate using a predetermined resist pattern as a mask. As the anisotropic dry etching, for example, reactive ion etching (RIE) can be employed.

  Next, as shown in FIG. 30B, the sacrificial material 33 is filled in the recess 31 a of the substrate 31. Specifically, a sufficient amount of sacrificial material 33 is deposited over the recess 31a and over the substrate 31, for example, by sputtering, and then the excess sacrificial material 33 deposited on the substrate 31 is removed by polishing. As the sacrificial material 33, for example, a photoresist can be employed.

  Next, as shown in FIG. 30C, the movable electrode 32 and the dielectric pattern 14 are formed. The method of forming the movable electrode 32 and the dielectric pattern 14 is the same as the method of forming the fixed electrode 12 and the dielectric pattern 14 described above with reference to FIGS. 6 (a) and 6 (b).

  Next, a sacrificial film 15 and a movable electrode 13 are formed as shown in FIG. These specific formation methods are the same as those described above with reference to FIGS. 6C and 7A.

  Next, as shown in FIG. 31B, a material film 16 is formed on the movable electrode 13. The material film 16 is for forming the above-described curved structure in the movable electrode 13 and is made of a material having a higher thermal expansion coefficient than that of the constituent material of the movable electrode 13. A specific method for forming the material film 16 is as described above with reference to FIG. When the temperature is lowered after this step, a larger contraction force is generated in the material film 16 than in the movable electrode 13.

  Next, as shown in FIG. 31C, the sacrificial film 15 and the sacrificial material 33 are removed by, for example, a wet etching method. When the sacrificial film 15 and the sacrificial material 33 are removed, the material film 16 contracts more than the movable electrode 13 and partially curves the movable electrode 13. For example, the variable capacitor X8 can be manufactured as described above. The material film 16 as an example of a means for bending the movable electrode 13 is not shown in FIG.

  Variable capacitor X8 can be driven in a manner similar to that described above with respect to variable capacitor X1. Specifically, as shown in FIG. 32, the volume of the gap G8 between the movable electrode 32 and the movable electrode 13 is maximum, and the volume of the gap G8 is the first state (initial state) shown in FIG. The gap volume can be continuously changed greatly between the minimum state and the second state shown in FIG. Therefore, according to the variable capacitor X8, similarly to the variable capacitor X1, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In the variable capacitor X8, the total length of the contour of the dielectric pattern 14 having a predetermined pattern shape on the opposing surface 32a of the movable electrode 32 is relatively long (that is, the dielectric pattern having the total length of the contour of the dielectric pattern 14). The length per unit area of 14 is relatively large). For this reason, electric charges easily escape from the dielectric pattern 14 to the facing surface 32a, and charging of the dielectric pattern 14 due to so-called charge transfer is suppressed. Therefore, in the variable capacitor X8, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor X1.

  FIG. 33 is a partial sectional view of a variable capacitor X9 according to the ninth embodiment of the present invention. FIG. 33 corresponds to FIG. 29 for the variable capacitor X8. The variable capacitor X9 includes a substrate 31, a movable electrode 32 having a curved shape, a movable electrode 13 having a curved shape, and a dielectric pattern. The variable capacitor X9 is different from the variable capacitor X8 in that the movable electrode 32 has a curved shape. The movable electrode 32 having a curved shape can be formed by using the same technique as that for forming the fixed electrode 12 having a curved shape in the manufacturing process of the variable capacitor X7 described above.

  Variable capacitor X9 can be driven in a manner similar to that described above with respect to variable capacitor X1. Specifically, as shown in FIG. 34, the volume of the gap G9 between the movable electrode 32 and the movable electrode 13 is maximum, and the first state (initial state) shown in FIG. The gap volume can be continuously changed greatly between the second state shown in FIG. Therefore, according to the variable capacitor X9, similarly to the variable capacitor X1, it is possible to realize a large variable amount or variable rate with respect to the capacitance.

  In the variable capacitor X9, the total length of the contour of the dielectric pattern 14 having a predetermined pattern shape on the opposing surface 32a of the movable electrode 32 is relatively long (that is, the dielectric pattern having the total length of the contour of the dielectric pattern 14). The length per unit area of 14 is relatively large). For this reason, electric charges easily escape from the dielectric pattern 14 to the facing surface 32a, and charging of the dielectric pattern 14 due to so-called charge transfer is suppressed. Therefore, in the variable capacitor X8, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor X1.

  FIG. 35 is a partial cross-sectional view of a variable capacitor X10 according to the tenth embodiment of the present invention. FIG. 35 corresponds to FIG. 29 for the variable capacitor X8. The variable capacitor X10 includes a substrate 31, a movable electrode 32 that does not have a curved structure, a movable electrode 13 that does not have a curved structure, a dielectric pattern 14, and an anchor portion 34. The variable capacitor X10 differs from the variable capacitor X8 in that the movable electrode 13 does not have a curved structure and includes an anchor portion 34. With respect to the variable capacitor X10, the variable capacitor X8 described above with reference to FIGS. 30 and 31 is provided except that the anchor portion 34 is embedded in the sacrificial film 15 and the material film 16 is not formed on the movable electrode 13. It can be manufactured by the same method as the manufacturing method.

  Variable capacitor X10 can be driven in a manner similar to that described above with respect to variable capacitor X1. Specifically, as shown in FIG. 36, the volume of the gap G10 between the movable electrode 32 and the movable electrode 13 is maximum, and the volume of the first state (initial state) shown in FIG. The gap volume can be continuously changed greatly between the minimum state and the second state shown in FIG. Therefore, according to the variable capacitor X10, similarly to the variable capacitor X1, a large variable amount or variable rate can be realized with respect to the capacitance.

  In the variable capacitor X10, the total length of the contour of the dielectric pattern 14 having a predetermined pattern shape on the facing surface 32a of the movable electrode 32 is relatively long (that is, the dielectric pattern having the total length of the contour of the dielectric pattern 14). The length per unit area of 14 is relatively large). For this reason, electric charges easily escape from the dielectric pattern 14 to the facing surface 32a, and charging of the dielectric pattern 14 due to so-called charge transfer is suppressed. Therefore, in the variable capacitor X10, fluctuations in drive voltage characteristics are suppressed for the same reason as described above with respect to the variable capacitor X1.

  Also in the above-described variable capacitors X1 and X2, an anchor portion for connecting both electrodes, such as the anchor portion 34 of the variable capacitor X10, may be provided.

  In the variable capacitors X8 to X10, instead of providing the dielectric pattern 14 on the opposed surface 32a of the movable electrode 32, the dielectric pattern 14 shown in FIG. You may provide on 13 opposing surfaces 13a. In the variable capacitors X8 to X10, in addition to providing the dielectric pattern 14 on the opposing surface 32a of the movable electrode 32, the dielectric pattern 14 ′ shown in FIG. 10 is movable as described above for the variable capacitor X1. You may provide on the opposing surface 13a of the electrode 13. FIG. In the variable capacitors X8 to X10, the conductor layer 17 shown in FIG. 11 may be provided on the dielectric pattern 14 in the same manner as described above for the variable capacitor X1.

  In the variable capacitors X8 to X10, the dielectric film 21 described above with respect to the variable capacitor X2 shown in FIG. 12 is not provided on the opposing surface 32a of the movable electrode 32 or the opposing surface 13a of the movable electrode 13 without providing the dielectric pattern 14. The conductive pattern 22 described above with respect to the variable capacitor X2 may be provided on the opposing surface 32a or the opposing surface 13a where the dielectric film 21 is not provided. In the variable capacitors X8 to X10, without providing the dielectric pattern 14, the dielectric film 21 and the conductor pattern 23 described above with respect to the variable capacitor X3 shown in FIG. 14 are placed on the facing surface 32a or the facing surface 13a. It may be provided. In the variable capacitors X8 to X10, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X4 shown in FIG. 16 may be provided on the opposing surface 32a or the opposing surface 13a without providing the dielectric pattern 14. Good. In the variable capacitors X8 to X10, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X5 shown in FIG. 18 are provided on the opposing surface 32a or the opposing surface 13a without providing the dielectric pattern 14, and The conductor pattern 26 described above with respect to the variable capacitor X5 may be provided on the facing surface 32a or the facing surface 13a where the dielectric film 24 and the conductor pattern 25 are not provided. In the variable capacitors X8 to X10, without providing the dielectric pattern 14, the dielectric film 24 and the conductor pattern 25 described above with respect to the variable capacitor X6 shown in FIG. 20 are provided on the opposing surface 32a or the opposing surface 13a, and The conductor pattern 27 described above with respect to the variable capacitor X6 may be provided on the facing surface 32a or the facing surface 13a where the dielectric film 24 and the conductor pattern 25 are not provided.

  The fixed electrode 12, the movable electrode 13, and the movable electrode 32 described above may have a curved shape different from that illustrated for each. For example, the fixed electrode 12 of the variable capacitors X <b> 1 to X <b> 7 may have a plurality of portions that curve so as to protrude toward the movable electrode 13 in the region facing the movable electrode 13. You may have at least one site | part which curves so that it may protrude to the other side. The movable electrode 13 of the variable capacitors X1 to X7 may have a plurality of portions that curve so as to protrude toward the fixed electrode 12 in the region facing the fixed electrode 12, or may be opposite to the fixed electrode 12. You may have at least one site | part which curves so that it may protrude to the side. The movable electrode 13 of the variable capacitors X8 to X10 may have a plurality of portions that curve so as to protrude toward the movable electrode 32 in the region facing the movable electrode 32, or is opposite to the movable electrode 32. You may have at least one site | part which curves so that it may protrude to the side. The movable electrode 32 of the variable capacitors X8 to X10 may have a plurality of portions that curve so as to protrude toward the movable electrode 13 in the region facing the movable electrode 13, or may be opposite to the movable electrode 13. You may have at least one site | part which curves so that it may protrude to the side.

  As a summary of the above, the configurations of the present invention and variations thereof are listed below as supplementary notes.

(Supplementary note 1) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface and having a portion curved so as to protrude toward the capacitor electrode;
And a dielectric pattern provided on the first facing surface or the second facing surface.
(Appendix 2) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
And a dielectric pattern provided on the first facing surface or the second facing surface.
(Additional remark 3) The variable capacitor of Additional remark 1 or 2 provided with a conductor layer on the said dielectric material pattern.
(Additional remark 4) The variable capacitor of Additional remark 1 or 2 provided with a dielectric pattern on the said 1st opposing surface or the said 2nd opposing surface in which the said dielectric material pattern is not provided.
(Supplementary note 5) The variable capacitor according to any one of supplementary notes 1 to 4, wherein a CV characteristic is adjusted by adjusting a shape and / or density of the dielectric pattern.
(Supplementary note 6) The variable capacitor according to supplementary note 5, wherein the dielectric pattern has a portion that changes from a dense portion to a rough portion.
(Supplementary note 7) The variable capacitor according to any one of supplementary notes 1 to 6, wherein the dielectric pattern includes a plurality of dielectric islands.
(Appendix 8) A capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface and having a portion curved so as to protrude toward the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductor pattern provided on the first opposing surface or the second opposing surface where the dielectric film is not provided.
(Supplementary note 9) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
A dielectric film provided on the first opposing surface or the second opposing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
And a conductor pattern provided on the first opposing surface or the second opposing surface where the dielectric film is not provided.
(Supplementary note 10) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface and having a portion curved so as to protrude toward the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
A variable capacitor comprising a conductor pattern provided on the dielectric film.
(Appendix 11) A capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
A variable capacitor comprising a conductor pattern provided on the dielectric film.
(Supplementary note 12) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface and having a portion curved so as to protrude toward the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductive pattern embedded in the dielectric film while being exposed on the movable capacitor electrode film side.
(Supplementary note 13) a capacitor electrode having a first facing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductive pattern embedded in the dielectric film while being exposed on the movable capacitor electrode film side.
(Supplementary Note 14) The variable capacitor according to Supplementary Note 12 or 13, wherein the conductor pattern is a conductor film having a plurality of openings.
(Supplementary Note 15) Any one of Supplementary Notes 12 to 14, wherein a surface of the dielectric film on the side of the movable capacitor electrode film and a surface of the conductive pattern on the side of the movable capacitor electrode film are flush with each other. The variable capacitor described in 1.
(Supplementary Note 16) From Supplementary Note 12, the surface on the movable capacitor electrode film side of the conductor pattern is retracted closer to the capacitor electrode side than the surface of the dielectric film on the movable capacitor electrode film side. The variable capacitor according to any one of 14.
(Supplementary note 17) From Supplementary note 12, the surface of the dielectric film on the side of the movable capacitor electrode film is retracted closer to the capacitor electrode side than the surface of the conductive pattern on the side of the movable capacitor electrode film. The variable capacitor according to any one of 14.
(Supplementary note 18) The variable capacitor according to any one of supplementary notes 1, 8, 10, and 12, comprising an anchor portion that partially connects the capacitor electrode and the movable capacitor electrode film.
(Supplementary note 19) The variable capacitor according to any one of supplementary notes 1 to 18, wherein the capacitor electrode is a fixed electrode.
(Supplementary note 20) The variable capacitor according to supplementary note 19, wherein the first facing surface of the fixed electrode has a region curved so as to protrude toward the movable capacitor electrode film.
(Supplementary note 21) The variable capacitor according to any one of supplementary notes 1 to 18, wherein the capacitor electrode is a movable capacitor electrode film.
(Supplementary note 22) The variable capacitor according to any one of supplementary notes 1 to 18, wherein the capacitor electrode is a movable capacitor electrode film having a portion curved so as to protrude toward the movable capacitor electrode film.
(Supplementary Note 23) A movable capacitor electrode film having a first facing surface;
A fixed capacitor electrode having a second facing surface having a region facing the first facing surface and curved so as to protrude toward the movable capacitor electrode film;
And a dielectric pattern provided on the first facing surface or the second facing surface.
(Appendix 24) A movable capacitor electrode film having a first facing surface;
A fixed capacitor electrode having a second facing surface having a region facing the first facing surface and curved so as to protrude toward the movable capacitor electrode film;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductor pattern provided on the first opposing surface or the second opposing surface where the dielectric film is not provided.
(Appendix 25) A movable capacitor electrode film having a first facing surface;
A fixed capacitor electrode having a second facing surface having a region facing the first facing surface and curved so as to protrude toward the movable capacitor electrode film;
A dielectric film provided on the first opposing surface or the second opposing surface;
A variable capacitor comprising a conductor pattern provided on the dielectric film.
(Supplementary Note 26) A movable capacitor electrode film having a first facing surface;
A fixed capacitor electrode having a second facing surface having a region facing the first facing surface and curved so as to protrude toward the movable capacitor electrode film;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductive pattern embedded in the dielectric film while being exposed on the movable capacitor electrode film side.

X1 to X10 Variable capacitors 11, 31 Substrate 12 Fixed electrodes 13, 32 Movable electrode 14 Dielectric pattern 17 Conductive layers 21, 24 Dielectric films 22, 23, 25, 26, 27 Conductor pattern 28 Hill portion 34 Anchor portion

Claims (10)

A capacitor electrode having a first opposing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
And a dielectric pattern provided on the first facing surface or the second facing surface.   The variable capacitor according to claim 1, further comprising a conductor layer on the dielectric pattern.   The variable capacitor according to claim 1, further comprising a dielectric pattern on the first facing surface or the second facing surface where the dielectric pattern is not provided.   4. The variable capacitor according to claim 1, wherein the CV characteristic is adjusted by adjusting the shape and / or density of the dielectric pattern. 5.   The variable capacitor according to claim 4, wherein the dielectric pattern has a portion that changes from a dense portion to a rough portion.   The variable capacitor according to claim 1, wherein the dielectric pattern includes a plurality of dielectric islands. A capacitor electrode having a first opposing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
A dielectric film provided on the first opposing surface or the second opposing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
And a conductor pattern provided on the first opposing surface or the second opposing surface where the dielectric film is not provided. A capacitor electrode having a first opposing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
A variable capacitor comprising a conductor pattern provided on the dielectric film. A capacitor electrode having a first opposing surface;
A movable capacitor electrode film having a second facing surface facing the first facing surface;
An anchor part for partially fixing the movable capacitor electrode film to the capacitor electrode;
A dielectric film provided on the first opposing surface or the second opposing surface;
And a conductive pattern embedded in the dielectric film while being exposed on the movable capacitor electrode film side.   The variable capacitor according to claim 7, wherein the conductor pattern is a conductor film having a plurality of openings.

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