JP2010135634A - Method for manufacturing semiconductor device, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device having movable portions with high reliability, and the semiconductor device. <P>SOLUTION: Upper driving electrodes 23 connected to supports 21 and an upper capacitance electrode 25 are extended in a beam shape through silicon nitride films 27. In other words, the silicon nitride films 27 are formed contacting with each upper surface of an end portion of the upper driving electrode 23 and an end portion of the upper capacitance electrode 25 which are separated and faced, and provided approximately parallel to the upper driving electrodes 23 and the upper capacitance electrode 25. The silicon nitride films 27 are formed by being deposited on an upper surface of a conductive film to be formed into the upper driving electrodes 23 and the upper capacitance electrode 25 in a continuous process by a CVD method, and, thereafter, by being patterned by a RIE method. The silicon nitride films 27 are formed so as to have less discontinuity and unevenness in film thickness or film property, and good adhesiveness to the upper driving electrodes 23 and the upper capacitance electrode 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor device having a movable part and the semiconductor device.

  In recent years, there is an increasing demand for variable capacitance elements, switches, and the like using micromachines using micro actuators or MEMS (Micro-Electro-Mechanical Systems) technology. Semiconductor devices with variable capacitance elements that use electrostatic actuators are well developed and compatible with manufacturing processes such as LSI (Large Scale Integrated circuit) and have relatively low power consumption. ing.

  For example, a driving upper electrode (upper driving electrode) is fixed to an anchor (post) arranged on a semiconductor substrate, and a driving lower electrode (lower driving electrode) and an RF lower electrode (lower part) are fixed on the semiconductor substrate. (Capacitance electrode) is formed, and the lower electrode for RF is disposed between the lower electrodes for driving, and an insulating film is formed on the lower electrode for driving so as to cover the lower electrode for driving, and on the lower electrode for RF An insulating film is formed so as to cover the RF lower electrode, and these RF lower electrode, RF upper electrode (upper capacitive electrode), and insulating film constitute a variable capacitance element, and drive with the RF upper electrode. An insulator is inserted between the upper electrode for RF, the upper electrode for RF and the upper electrode for driving are electrically isolated, and the lower electrode for RF is arranged to face the upper electrode for RF Semiconductor device disclosed That (for example, see Patent Document 1.).

However, the disclosed semiconductor device has a possibility that the reliability is not sufficient when the movable portion performs a mechanical operation. That is, the disclosed semiconductor device has a structure in which an insulator is inserted between the upper electrode for RF and the upper electrode for driving, and the upper electrode for RF and the upper electrode for driving are patterned in manufacturing. Later, it is presumed that an insulator is formed on the sacrificial film, the RF upper electrode, and the driving upper electrode in the lower part and processed by CDE (Chemical Dry Etching) or the like. At that time, in the insulator, a portion with poor coverage is generated at the ends of the upper electrode for RF and the upper electrode for driving, and etching of the portion with poor coverage may be uneven, and the insulator is thin or thin. There is a problem that it may be formed.
JP 2007-242607 A (16th and 17th pages, FIG. 30A)

  The present invention provides a method of manufacturing a semiconductor device having a highly reliable movable part and a semiconductor device.

  According to another aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising: forming a support electrode, a lower drive electrode, and a lower capacitor electrode, which are spaced substantially linearly on a surface of a semiconductor substrate; Forming a first insulating film on surfaces of the drive electrode and the lower capacitor electrode; and forming a sacrificial film on the surface of the semiconductor substrate so as to cover the first insulating film; Forming an opening that communicates with the support electrode in the sacrificial film and the first insulating film on the surface; and forming a conductor that fills the opening and covers the surface of the sacrificial film; and A step of forming a second insulating film, a step of patterning so as to leave the second insulating film at a position facing the gap between the lower drive electrode and the lower capacitor electrode, and the remaining first 2 under the central part of the insulating film, Forming a separation groove at a position facing the gap between the electrode and the lower capacitor electrode, and patterning the conductor so as to leave the conductor at a position facing the lower drive electrode and the lower capacitor electrode; and And a step of removing the sacrificial film from the portion removed by patterning.

Further, a semiconductor device according to another aspect of the present invention includes a semiconductor substrate, a support electrode formed on the upper surface of the semiconductor substrate, a lower drive electrode formed on the upper surface of the semiconductor substrate and separated from the support electrode, A lower capacitor electrode disposed on a top surface of the semiconductor substrate in a direction connecting the support electrode and the lower drive electrode apart from the support electrode and the lower drive electrode; and the lower drive electrode and the lower capacitor A first insulating film covering the electrode, a column electrode connected to the support electrode perpendicular to the upper surface of the semiconductor substrate, and opposed to and spaced from the lower drive electrode, and substantially perpendicular to the column electrode A beam-shaped upper drive electrode connected to the upper drive electrode, a second insulating film connected in surface contact with the upper drive electrode and extending in parallel, and opposed to and spaced from the lower capacitor electrode. Vertically, the second insulation Characterized in that it comprises a contact with the connected beam-like upper capacitor electrode on the top surface edge and.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the manufacturing method and semiconductor device of a semiconductor device which have a highly reliable movable part.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same components are denoted by the same reference numerals.

  A semiconductor device manufacturing method and a semiconductor device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1A and 1B are diagrams schematically illustrating a configuration of a semiconductor device, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA in FIG. FIG. 2 is a structural cross-sectional view schematically showing the semiconductor device manufacturing method in the order of steps. FIG. 3 is a structural cross-sectional view schematically showing the semiconductor device manufacturing method in the order of steps following FIG. FIG. 4 is a cross-sectional view schematically showing one mode of operation of the semiconductor device.

  As shown in FIG. 1, the semiconductor device 1 includes a support electrode 11 formed on one surface, which is an upper surface of opposing planes of the semiconductor substrate 10, and the support electrode 11 is separated from the upper surface of the semiconductor substrate 10. The lower drive electrode 13 formed in this manner and the lower capacitor electrode formed on the upper surface of the semiconductor substrate 10 in a direction connecting the support electrode 11 and the lower drive electrode 13 with the support electrode 11 and the lower drive electrode 13 being separated from each other. 15, an insulating film 17 that is a first insulating film covering the lower drive electrode 13 and the lower capacitor electrode 15, and a column 21 that is a column electrode connected to the support electrode 11 perpendicular to the upper surface of the semiconductor substrate 10. A beam-like upper drive electrode 23 facing and spaced apart from the lower drive electrode 13 and connected substantially perpendicularly to the support column 21; and a first electrode extending in parallel to the upper surface of the upper drive electrode 23 in surface contact. Silico, an insulating film of 2 A nitride film 27 and a beam-shaped upper capacitor electrode 25 which is opposed to and spaced from the lower capacitor electrode 15 and is substantially perpendicular to the support column 21 and connected in contact with the silicon nitride film 27 at the upper end portion are provided. . Note that the upper drive electrode 23 and the like formed on the surface of the semiconductor device 1 are set above the surface of the semiconductor device 1.

  As shown in FIGS. 1A and 1B, the support electrode 11, the lower drive electrode 13, the lower capacitor electrode 15, and the lower drive electrode 13 are formed on the upper surface of the semiconductor substrate 10 from one side to the other side. , And the support electrodes 11 are arranged substantially linearly apart from each other, with the surfaces thereof having substantially the same height. An insulating film 17 is disposed so as to cover the support electrode 11, the lower drive electrode 13, and the lower capacitor electrode 15 except for the connection portion with the support column 21.

  The column 21 is electrically and mechanically connected to a part of the upper surface of the support electrode 11. The upper drive electrode 23 is integrally connected to the position on the upper end side of the support column 21 facing the support electrode 11 through a connecting portion therebetween. That is, the upper drive electrode 23 is continuous from the upper end side of the support electrode 11 to the upper side opposite to the lower drive electrode 13, unlike the support electrode 11 and the lower drive electrode 13 that are separated from each other. Is formed.

  The upper drive electrode 23, the upper capacitive electrode 25, and the upper drive electrode 23 that are sequentially disposed between the support columns 21 on both sides correspond to the lower drive electrode 13, the lower capacitive electrode 15, and the lower drive electrode 13, respectively. For example, the air gap 51 of about 1 to 2 μm is placed and arranged almost linearly on the upper side. The upper drive electrode 23 and the upper capacitor electrode 25 are spaced apart from each other, and a strip-shaped silicon nitride film 27 disposed in contact with the upper surface side of the opposite ends mechanically connects each other. . A series of the upper drive electrode 23 and the upper capacitive electrode 25 supported by the support column 21 are narrowed or widened with respect to the corresponding lower drive electrode 13 and the lower capacitive electrode 15 (the gap 51 exists between them). Mechanical movement is possible.

  The support electrode 11, the lower drive electrode 13, the lower capacitive electrode 15, the support column 21, the upper drive electrode 23, and the upper capacitive electrode 25 are made of aluminum (Al) or an aluminum alloy containing Si or Cu. In addition, for example, these electrodes can be formed of a material containing at least one of Pt, Sr, Ru, Cr, Mo, W, Ti, Ta, Cu, and Ni as a main component. is there. The insulating film 17 is made of a silicon nitride film, an aluminum oxide film, or a laminated film of a silicon nitride film and an aluminum oxide film. In addition, the insulating film 17 can be replaced with, for example, a silicon oxide film, a silicon oxynitride film, or a laminated film including at least one of them.

  Next, a method for manufacturing the semiconductor device 1 will be described. In the description of the manufacturing method, supplementation of the configuration of the semiconductor device 1, supplementation of materials used, and the like are performed.

  As shown in FIG. 2A, for example, on the semiconductor substrate 10 made of silicon having an insulating film (not shown) on the surface, the support electrode 11, the lower drive electrode 13, and the lower capacitor electrode 15 are made of Al. The conductors are arranged in a substantially straight line, and are deposited by a sputtering method so that the lower drive electrode 13 and the support electrode 11 are arranged almost symmetrically with the lower capacitor electrode 15 in the center, and includes etching processing and the like. It is patterned into a desired shape by a known lithography method. Note that a part of an LSI including elements such as transistors, resistors, and capacitors can be formed on the semiconductor substrate 10 in advance.

  As shown in FIG. 2B, a silicon nitride film is formed on the surface of the semiconductor substrate 10 by, for example, a CVD (Chemical Vapor Deposition) method so as to cover the support electrode 11, the lower drive electrode 13, and the lower capacitor electrode 15. An insulating film 17 made of is formed. Note that the insulating film 17 can be formed by a sputtering method.

  As shown in FIG. 2C, a sacrificial film 31 made of, for example, photosensitive polyimide is formed by a coating method so as to cover the insulating film 17, and then the sacrificial film 31 is supported by a lithography method. An opening 32 communicating with the insulating film 17 on the electrode 11 is formed. Note that non-photosensitive polyimide can be used, and for example, patterning can be performed using a photoresist by a known lithography method including etching.

  As shown in FIG. 2D, with the sacrificial film 31 as a mask, the insulating film 17 exposed at the bottom of the opening 32 is etched by, for example, RIE (Reactive Ion Etching). The opening 32 communicates with the upper surface of the support electrode 11.

  As shown in FIG. 2E, a conductive film 33 made of Al filling the opening 32 and covering the surface of the sacrificial film 31 is deposited by the sputtering method, and the conductive film is formed on the conductive film 33 as a continuous process. A silicon nitride film 27a having a compressive stress with respect to 33 is deposited by the CVD method.

  As shown in FIG. 3A, strips (see FIG. 3) are formed on the surface of the silicon nitride film 27a so that the silicon nitride film 27 is left at the upper position facing the gap between the lower drive electrode 13 and the lower capacitor electrode 15. A photoresist 38 patterned so as to be the silicon nitride film 27 of 1 (a) is formed.

  As shown in FIG. 3B, the silicon nitride film 27 is formed by etching, for example, by the RIE method using the photoresist 38 as a mask. The silicon nitride film 27 is hardly formed under the photoresist 38 and is formed in a shape that extends the side surface of the photoresist 38.

  As shown in FIG. 3C, after removing the photoresist 38, a photoresist 39 is formed on the surface of the silicon nitride film 27 and the conductive film 33, and is opposed to the lower drive electrode 13 and the lower capacitor electrode 15, respectively. An opening 40 for separating the upper drive electrode 23 and the upper capacitor electrode 25 is formed at a position passing through the central portion of the silicon nitride film 27. The silicon nitride film 27 and the conductive film 33 are exposed at the bottom of the opening 40. At the same time that the opening 40 is formed, an opening for forming a hole 26 penetrating the upper drive electrode 23 and the upper capacitor electrode 25 shown in FIG. It is possible.

  As shown in FIG. 3D, using the photoresist 39 as a mask, the conductive film 33 is etched by, for example, an etching method using a chemical solution mainly composed of phosphoric acid, nitric acid, and acetic acid. The conductive film 33 exposed at the bottom of the opening 40 and the conductive film 33 below the silicon nitride film 27 are etched to form an opening 41 that is a separation groove. Since the opening 41 is also etched in the direction along the bottom surface connected to the opening 40 of the photoresist 39 by the wet etching method, the opening 41 has a portion wider than the opening 40. Further, etching is performed in a direction along the bottom surface of the silicon nitride film 27, and the conductive film 33 under the silicon nitride film 27 is removed. After the etching, the silicon nitride film 27 straddles the opening 41 at the center and is in contact with the upper surfaces of the upper drive electrode 23 and the upper capacitor electrode 25 that are separated at both ends.

  As shown in FIG. 1B, after removing the photoresist 39, the sacrificial film 31 is etched from above the semiconductor substrate 10 by, for example, the CDE method using oxygen plasma. Etching gas or the like enters through the opening 41 and the hole 26 between the upper drive electrode 23 and the upper capacitor electrode 25, reacts with the sacrificial film 31, and is gasified to remove the sacrificial film 31. As a result, the semiconductor device 1 shown in FIG. 1 is completed.

  In the semiconductor device 1, a drive voltage is applied to the upper drive electrode 23 and the lower drive electrode 13 connected to the support electrode 11 via a wiring or the like not shown. An electrostatic attractive force is generated between the lower drive electrode 13 and the upper drive electrode 23, and the two electrodes attract each other.

  As shown in FIG. 4, the upper drive electrode 23 is attracted toward the lower drive electrode 13 by this electrostatic attraction, and the upper drive electrode 23 and the connection portion extending from the upper drive electrode 23 to the column 21 are bent, The upper capacitor electrode 25 is in contact with the insulating film 17 on the lower capacitor electrode 15. As a result, an MIM (Metal Insulator Metal) capacitor having a certain capacitance is formed between the lower capacitor electrode 15 and the upper capacitor electrode 25. When the drive voltage is cut, the electrostatic attraction is lost, the position returns to the position before the drive voltage is applied, and the capacity becomes small enough to be ignored. By connecting wirings (not shown) to the lower capacitor electrode 15 and the upper capacitor electrode 25, the semiconductor device 1 can be used as a circuit element having a certain capacity in response to voltage application.

  As described above, the semiconductor device 1 is substantially in contact with the upper drive electrode 23 and the upper capacitor electrode 25 in contact with the upper surfaces of the end portions of the upper drive electrode 23 and the end portions of the upper capacitor electrode 25 that are spaced apart from each other. A silicon nitride film 27 arranged in parallel is formed. The silicon nitride film 27 is deposited on the upper surface of the conductive film 33 to be the upper drive electrode 23 and the upper capacitor electrode 25 by a CVD method as a continuous process and then patterned by the RIE method. That is, the silicon nitride film 27 has few discontinuous or inhomogeneous portions in film thickness and film quality, and has good adhesion to the upper drive electrode 23 and the upper capacitor electrode 25.

  As a result, the silicon nitride film 27 can suppress the occurrence of a starting point leading to fatigue damage even if the mechanical movement of attracting the lower drive electrode 13 and the upper drive electrode 23 by electrostatic attraction is repeated. It becomes possible. Further, the possibility that the silicon nitride film 27 is peeled off from the upper drive electrode 23 and the upper capacitor electrode 25 is reduced. That is, the semiconductor device 1 has a highly reliable movable part.

  A semiconductor device manufacturing method and a semiconductor device according to Embodiment 2 of the present invention will be described with reference to FIG. 5A and 5B are diagrams schematically illustrating the configuration of the semiconductor device, in which FIG. 5A is a cross-sectional view, and FIG. 5B is a cross-sectional view illustrating a part of FIG. This is different from the semiconductor device manufacturing method of the first embodiment in that the silicon nitride film has residual stress. In addition, the same code | symbol is attached | subjected to the same component as Example 1, and the description is abbreviate | omitted.

  As shown in FIG. 5, in the semiconductor device 2, the silicon nitride film 27 of the semiconductor device 1 of the first embodiment is replaced with a silicon nitride film 67 that generates a residual stress (compressive stress). The silicon nitride film 67 is in contact with the upper surfaces of the upper drive electrode 23 and the upper capacitor electrode 25 and has a shape having a convex curved surface in the opposite direction with respect to the semiconductor substrate 10 (hereinafter referred to as “curve upward”). ).

  The upper drive electrode 23 in contact with one end of the silicon nitride film 67 is bent in a direction in which the end facing the upper capacitor electrode 25 is closer to the semiconductor substrate 10 than the connection portion connected to the column 21. ing.

  The upper capacitor electrode 25 in contact with the other end of the silicon nitride film 67 has an end facing the upper drive electrode 23 at a position closer to the semiconductor substrate 10 than an end of the upper drive electrode 23, and protrudes upward. Bent along the bent silicon nitride film 67. When the upper capacitor electrode 25 is no longer in contact with the silicon nitride film 67, the upper capacitor electrode 25 is bent downward in a convex manner contrary to the bending of the silicon nitride film 67, and becomes substantially parallel to the surface of the semiconductor substrate 10 at the center.

The semiconductor device 2 is the same as the method of manufacturing the semiconductor device 1 of the first embodiment except that the method of manufacturing the silicon nitride film 67 is different from that of the silicon nitride film 27. For example, the silicon nitride film 67 is formed in a shape having a convex curved surface in the opposite direction to the semiconductor substrate 10 by changing the pressure during CVD. As the stress of the silicon nitride film 67, a compressive stress can be obtained during CVD, for example, by applying a high vacuum, or a compressive stress can be obtained by reducing the flow rate of SiH ₄ , or the NH ₃ flow rate can be increased. When it is lowered, compressive stress can be obtained. Further, for example, in an apparatus having an RF output of two frequencies, compressive stress can be obtained by increasing the ratio of the RF output on the low frequency side, and compressive stress can be obtained by increasing the RF output of the two frequencies. it can.

  As a result, when the sacrificial film 31 is removed in the same manner as in the first embodiment, the silicon nitride film 67 bends upward, and the end of the upper drive electrode 23 in contact with the silicon nitride film 67 has a semiconductor substrate. 10, the upper capacitor electrode 25 is bent along the silicon nitride film 67 at the end, and the central portion is closer to the surface direction of the semiconductor substrate 10 as compared with the first embodiment, and the surface is closer to the surface. The shape is almost parallel.

  In the semiconductor device 2, since the end of the upper drive electrode 23 is close to the semiconductor substrate 10, that is, the lower drive electrode 13, the upper capacitance electrode 25 is driven at a lower drive voltage than the drive voltage of the first embodiment. Comes into contact with the insulating film 17 on the lower capacitor electrode 15. In addition, the semiconductor device 2 has the same effects as those of the semiconductor device 1 of the first embodiment.

  As a modification of the second embodiment, another semiconductor device can be formed by replacing the silicon nitride film 67 of the semiconductor device 2 with a silicon nitride film having a residual stress bending in the opposite direction. is there. That is, when the silicon nitride film is bent convexly toward the semiconductor substrate 10, the upper capacitor electrode 25 can be disposed at a position farther from the semiconductor substrate 10 than the upper capacitor electrode 25 of the first embodiment. . In a semiconductor device having a silicon nitride film that bends toward the semiconductor substrate 10 side, even if the sacrificial film is thinly formed, the gap between the lower capacitor electrode 15 and the upper capacitor electrode 25 can be made larger. The time required for the manufacturing process can be shortened by the thinness.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the embodiments, the example in which the semiconductor substrate is silicon has been shown. However, the semiconductor substrate may be a compound semiconductor such as GaAs or InP, or an oxide substrate such as silicon oxide, or sapphire or silicon oxide. It may be silicon formed on an oxide such as silicon or a compound semiconductor.

In addition, configurations as described in the following supplementary notes are conceivable.
(Supplementary Note 1) A support electrode, a lower drive electrode, and a lower capacitor electrode, which are spaced apart substantially linearly, are formed on the surface of the semiconductor substrate, and the support electrode, the lower drive electrode, and the lower capacitor electrode are formed. Forming a first insulating film on the surface; forming a sacrificial film on the surface of the semiconductor substrate so as to cover the first insulating film; and the sacrificial film on the surface of the support electrode and the first Forming an opening leading to the support electrode in the insulating film, forming a conductor covering the surface of the sacrificial film by filling the opening, and forming a second insulating film on the conductor A step of patterning so as to leave the second insulating film at a position facing a gap between the lower drive electrode and the lower capacitor electrode; and a step below the central portion of the remaining second insulating film. Side and in front of the lower drive electrode and the lower capacitor electrode Forming a separation groove at a position facing the gap and patterning the conductor so as to leave the conductor at a position facing the lower drive electrode and the lower capacitor electrode; and a portion where the conductor is patterned and removed And a step of removing the sacrificial film from the semiconductor device.

(Supplementary Note 2) The conductor is connected to the support electrode at both ends, and is opposed to the upper drive electrode facing the lower drive electrode, the second insulating film, and the lower capacitance electrode from one support electrode. The manufacturing method of the semiconductor device according to appendix 1, wherein the semiconductor device is connected to the upper capacitor electrode and connected symmetrically from the center of the upper capacitor electrode to the other support electrode.

(Additional remark 3) The said conductor is a manufacturing method of the semiconductor device of Additional remark 1 with which the said 2nd insulating film is formed by CVD method after that by the sputtering method.

(Additional remark 4) The said conductor is a manufacturing method of the semiconductor device of Additional remark 1 which has a through-hole perpendicular | vertical to the surface of the said semiconductor substrate.

(Additional remark 5) The said sacrificial film is a manufacturing method of the semiconductor device of Additional remark 1 which is a polyimide resin.

(Supplementary note 6) The second insulating film is formed in a strip shape, and connects one end portion and the upper drive electrode, and connects the other end portion and the upper capacitive electrode. A method for manufacturing a semiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the semiconductor device which concerns on Example 1 of this invention, Fig.1 (a) is a top view, FIG.1 (b) is sectional drawing along the AA of Fig.1 (a). . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural cross-sectional view schematically showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention in the order of steps. Sectional drawing which shows typically the manufacturing method following FIG. 2 of the semiconductor device which concerns on Example 1 of this invention in order of a process. Sectional drawing which shows typically one form of operation | movement of the semiconductor device which concerns on Example 1 of this invention. FIGS. 5A and 5B are diagrams schematically illustrating a configuration of a semiconductor device according to a second embodiment of the present invention, in which FIG. 5A is a cross-sectional view, and FIG. 5B is an enlarged cross-sectional view of a part of FIG. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Semiconductor device 10 Semiconductor substrate 11 Support electrode 13 Lower drive electrode 15 Lower capacitive electrode 17 Insulating film 21 Post 23 Upper drive electrode 25 Upper capacitive electrode 26 Holes 27, 27a, 67 Silicon nitride film 31 Sacrificial films 32, 40, 41 Opening 33 Conductive film 38, 39 Photo resist 51 Gaps

Claims (5)

A support electrode, a lower drive electrode, and a lower capacitor electrode are formed on the surface of the semiconductor substrate so as to be spaced apart substantially linearly, and a first electrode is formed on the surfaces of the support electrode, the lower drive electrode, and the lower capacitor electrode. Forming an insulating film of
A sacrificial film is formed on the surface of the semiconductor substrate so as to cover the first insulating film, and an opening communicating with the support electrode is formed in the sacrificial film and the first insulating film on the surface of the support electrode. Process,
Forming a conductor that fills the opening, covers the surface of the sacrificial film, and forms a second insulating film on the conductor;
Patterning to leave the second insulating film at a position facing the gap between the lower drive electrode and the lower capacitor electrode;
A separation groove is formed at a position opposite to the gap between the lower drive electrode and the lower capacitor electrode, passing under the central portion of the remaining second insulating film, and the lower drive electrode and the lower capacitor Patterning to leave the conductor in a position facing the electrode;
Removing the sacrificial film from a portion where the conductor has been patterned and removed;
A method for manufacturing a semiconductor device, comprising:   2. The method of manufacturing a semiconductor device according to claim 1, wherein the second insulating film is a silicon nitride film.   The method of manufacturing a semiconductor device according to claim 1, wherein the conductor is removed by wet etching.   4. The method of manufacturing a semiconductor device according to claim 1, wherein the second insulating film is formed by controlling stress. A semiconductor substrate;
A support electrode formed on the upper surface of the semiconductor substrate;
A lower drive electrode formed on the upper surface of the semiconductor substrate and spaced apart from the support electrode;
A lower capacitor electrode disposed on a top surface of the semiconductor substrate in a direction connecting the support electrode and the lower drive electrode apart from the support electrode and the lower drive electrode;
A first insulating film covering the lower drive electrode and the lower capacitor electrode;
A column electrode connected to the support electrode perpendicular to the top surface of the semiconductor substrate;
A beam-like upper drive electrode connected to the pillar electrode substantially perpendicularly to and opposite to the lower drive electrode; and
A second insulating film connected in surface contact with the upper end of the upper drive electrode and extending in parallel;
A beam-shaped upper capacitor electrode connected to and in contact with the second insulating film at the upper end, substantially perpendicular to the column electrode, facing and spaced from the lower capacitor electrode;
A semiconductor device comprising:

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