JP2010030020A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide structure capable of reducing an influence of a charge in a dicing step of a substrate in an electronic device, disposed with a function element in a hollow part on the substrate, and a manufacturing method therefor. <P>SOLUTION: This electronic device 10 comprises a substrate 11, a function element 10X arranged on the substrate, and an element surrounding structure 10P provided on the substrate, and surrounding and defining a hollow part 10C disposed with the function element. At least one part of the element surrounding structure is constituted of conductors 17, 19, and wiring structures 17, 19 for electrically connecting the conductors are provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device, and more particularly to a structure and a manufacturing method suitable for forming a MEMS element on a substrate.

  In general, as one method for forming a MEMS element, there is a case where a fine MEMS structure is formed on a substrate such as a semiconductor substrate using a semiconductor formation technique, and the MEMS structure is exposed on the substrate. is there. The exposure of the MEMS structure as described above is required to ensure various functions of the MEMS element, for example, various operations such as deformation and vibration of the movable electrode.

  In the case of manufacturing a structure in which the MEMS element is exposed on the substrate, for example, when a substrate covering structure including an insulating film or a wiring layer is formed on the substrate, it is incorporated into the substrate covering structure. By forming a MEMS structure together with a sacrificial layer as necessary, covering with the substrate covering structure resist, etc., opening a part of the resist, and performing a release process of performing an etching process from the opening. It is necessary to remove the sacrificial layer together with a part of the substrate covering structure to expose the MEMS structure.

  In this case, in the process of manufacturing an electronic device including a MEMS element, a process of dividing the substrate by dicing is generally required. However, in the dicing process, the frictional heat between the dicing blade and the substrate is cooled or the cutting residue is reduced. Since it is necessary to spray pure water to perform removal, dicing cannot be performed with the MEMS structure exposed in order to avoid mechanical damage due to the spraying of the pure water. For this reason, the substrate is diced first, and then the release process is performed.

On the other hand, in the following Patent Document 1, a functional structure 3X constituting a functional element such as a MEMS element is formed on a substrate 1, and the functional structure 3X is disposed in a cavity C on the substrate 1. Thus, an electronic device is disclosed in which a substrate covering structure that surrounds and defines the cavity C is formed on the substrate 1. This document also describes a process for sealing the functional structure 3X in the cavity C after the release process and then dicing the substrate as a method for manufacturing the electronic device. According to this method, since the dicing process can be performed after the release process, an effect that the release process can be performed in units of substrates before dicing can be obtained.
JP 2007-216308 A

  However, even when the release process is performed after the substrate is diced as described above, the insulator surrounding the MEMS structure is easily charged by the friction generated by the spraying of the pure water, and this charging causes the MEMS in the subsequent release process. There is a problem that the movable part of the structure is electrostatically attracted to the fixed part and causes sticking (sticking of the movable part).

  On the other hand, in the method described in Patent Document 1, since the release process is performed before the dicing process, the sticking due to the dicing process does not occur. However, in the dicing process performed after the MEMS structure is released. Since the insulator is charged in the same manner as described above, the MEMS structure is electrically affected by this charging, so that the operating characteristics may change and the structure may be damaged.

  Therefore, the present invention solves the above problems, and the problem is that in an electronic device in which a functional element is arranged in a cavity on a substrate, a structure capable of reducing the influence of charging due to a substrate dicing process and It is to provide a manufacturing method.

  In view of such circumstances, an electronic device according to the present invention includes a substrate, a functional element disposed on the substrate, and an element that is provided on the substrate and surrounds and defines a cavity in which the functional element is disposed. An electronic device including a surrounding structure is characterized in that at least a part of the element surrounding structure is made of a conductor, and a wiring structure for electrically connecting the conductor is provided.

  According to the present invention, at least a part of the element surrounding structure that surrounds and defines the cavity in which the functional element is disposed is constituted by the conductor, and the wiring structure for electrically connecting the conductor is provided. By being provided, by connecting the conductor to a predetermined potential through the wiring structure, the influence on the functional element due to the charging generated during the dicing of the substrate can be mitigated, and the static electricity charged around the conductor and the wiring can be reduced. Since it can be removed through the structure, the electrical influence on the functional element can be reduced. Therefore, a functional element having good characteristics can be manufactured safely and reliably.

  In one aspect of the present invention, the conductor covers at least an upper portion of the cavity. According to this, since the conductor covers at least the upper portion of the cavity, charging of the surrounding substrate covering structure during dicing of the substrate can be more easily avoided. In addition, since it is usually not necessary to form an insulating layer or wiring layer above the cavity, the electrical effect on the functional elements should be reduced without affecting the circuit configuration or wiring structure around the cavity. Is possible.

  In another aspect of the invention, the wiring structure conductively connects the conductor to the substrate. In general, in the case of the present invention, the conductor around the element structure may be connected to an arbitrary terminal portion via the wiring structure, but the conductor is conductively connected to the substrate via the wiring structure. Thus, the conductor can be more easily electrically connected to the ground potential or other potential.

  In this case, it is preferable that a carrier region having a higher concentration than the surrounding substrate portion is provided in the surface layer portion of the substrate to which the wiring structure is conductively connected. According to this, by providing a higher concentration carrier region in the surface layer portion of the substrate to which the wiring structure is conductively connected than the other substrate portions, the conductive connection resistance between the wiring structure and the substrate can be reduced, and the conductor can be more The conductive connection to the substrate can be ensured.

  In another aspect of the present invention, the element surrounding structure has a conductive conductive side wall portion that constitutes at least a part of the side wall of the cavity, and the wiring structure is separately provided outside the conductive side wall portion. ing. According to this, the wiring structure is separately provided outside the conductive side wall portion constituting at least a part of the side wall of the cavity portion in the element surrounding structure, thereby affecting the erosion status of the conductive side wall portion when forming the cavity portion. It is possible to reliably connect the conductors without being connected.

  In a further different aspect of the present invention, the semiconductor device further includes a semiconductor circuit formed on or above the substrate and conductively connected to the functional element. According to this, various circuits including a functional element such as a MEMS element such as an oscillation circuit and a filter circuit can be easily configured by providing the functional element and the semiconductor circuit in a conductive connection state on a common substrate. it can.

  Next, a method for manufacturing an electronic device according to the present invention includes a functional element forming step of forming a functional element on a substrate, a substrate covering step of forming a substrate covering structure on the substrate and the functional element, and the substrate covering An element exposing step of exposing the functional element by removing a portion of the structure on the functional element, and a structure together with the remainder of the substrate covering structure in the element exposing step by closing the upper portion of the functional element And surrounding and defining a cavity in which the functional element is accommodated to complete an element surrounding structure including a wiring structure for electrically connecting at least a part of the conductor and electrically connecting the conductor And a substrate dicing step for dicing the substrate after the element closing step.

  According to the present invention, the element closing process is performed after the element exposure process is performed, and then the substrate dicing process is performed, so that sticking of the functional element due to charging during dicing of the substrate can be avoided, and At least a part of the conductor is made of a conductor, and this conductor can be electrically connected by the wiring structure, so that the electrical influence on the functional element due to the charging during the dicing of the substrate can be reduced and at the same time the charged state can be reduced. It can be removed through the conductor and the wiring structure. Therefore, a functional element having good characteristics can be manufactured safely and reliably.

  In the present specification and the appended claims, the terms “vertical direction”, “upper”, “upper”, “lower”, “lower” and the like are functional elements or In the device structure in which the functional structure is provided, it expresses the case where the substrate side is the lower or lower side, and the functional element or functional structure side is the upper or upper side, and represents the actual vertical direction depending on the posture of the device , Does not mean the upper, upper, lower and lower parts in the vertical direction.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
First, an electronic device according to a first embodiment of the present invention will be described with reference to FIG. 1A to 1E are schematic process cross-sectional views showing the manufacturing process of the present embodiment. In the electronic device 10 of the present embodiment, a MEMS structure (functional structure) 10X constituting a MEMS element (for example, a MEMS vibrator) as a functional element is formed on a substrate 11 made of a semiconductor such as silicon single crystal. It will be.

In this embodiment, as shown in FIG. 1A, impurity regions 11A and 11B having a carrier concentration higher than that of the substrate are formed in the surface layer portion of the substrate 11 by an impurity diffusion method, an ion implantation method, or the like. Here, the impurity region 11A is either a p-type region (well) or an n-type region (well) depending on the driving mode of the MEMS structure 10X, and is preferably connected to a constant potential to reduce the parasitic capacitance of the MEMS structure. Has the function of mitigating. The impurity region 11B is for obtaining an ohmic contact at a conductive connection portion between a wiring layer and a substrate 11 to be described later, and the peripheral portion (a well region formed on the substrate 11 or its surface layer portion) is a p-type semiconductor. For example, a higher concentration p ⁺ -type region (well) is used, and if the surrounding portion is an n-type semiconductor, a higher concentration n ⁺ -type region (well) is used.

  The impurity region 11B is formed continuously (for example, in a ring shape) along a closed curve surrounding the MEMS structure 10X in a plane, or is discontinuous on the closed curve surrounding the MEMS structure 10X in a plane. Are dispersed at a plurality of locations.

  Next, a base insulating layer 12A made of a silicon nitride film or the like is formed on the substrate 11 by a CVD method, a sputtering method, or the like. The base insulating layer 12A is made of a material having resistance to etching performed in a release process described later, and functions as a so-called etching stop layer. The base insulating layer 12A is formed in a form limited to a range including a planar range in which the MEMS structure 10X is formed by a patterning process. This eliminates an obstacle to the formation of the semiconductor circuit on the substrate 11 and above.

  A surface insulating film made of a silicon oxide film or the like may be separately formed between the substrate 11 and the base insulating film 12A. This surface insulating film can be used as an inter-element isolation film or the like when a substrate 11 and a semiconductor circuit are formed thereon.

  A MEMS structure 10X is formed on the base insulating layer 12A. The MEMS structure 10X can have various configurations. In the illustrated example, the MEMS structure 10X has a vibrator structure in which the fixed electrode 13 and the movable electrode 14 are arranged to face each other in the thickness direction of the substrate 11. is there. The fixed electrode 13 and the movable electrode 14 are formed by a vapor deposition method, a sputtering method, a CVD method, or the like, for example, a conductive polysilicon film. The fixed electrode 13 is formed in layers on the base insulating layer 12A. The movable electrode 14 has a support portion 14a formed on the base insulating film 12A, and a sacrificial layer 12B made of PSG (phosphorus doped glass), silicon oxide film or the like on the base insulating film 12A and the fixed electrode 13. And a stacked movable portion 14b. The movable portion 14b is disposed above the fixed electrode 13 via the sacrificial layer 12B.

  The MEMS structure 10X is formed in a range that overlaps with the impurity region 11A provided in the surface layer portion of the substrate 11 in a plane, and the impurity region 11B is formed by the opening 12a through the base insulating film 12A, The surface is exposed without being covered with the surface insulating film and the sacrificial layer 12B.

  Next, as shown in FIG. 1B, an interlayer insulating film 16 made of a silicon oxide film or the like is formed on the substrate 11 and the MEMS structure 10X by a sputtering method, a CVD method, or the like. Further, the interlayer insulating film 16 is provided with an opening 16a configured in a frame shape (for example, an annular shape) along a closed curve surrounding the MEMS structure 10X in a plane. The opening 16a does not need to be formed in the entire closed curve surrounding the MEMS structure 10X in a plane, and a portion where the opening 16a is not provided may exist in a part of the closed curve.

  Thereafter, a wiring layer 17 made of aluminum or the like is formed on the interlayer insulating film 16, and a part of the wiring layer 17 is provided on the surface layer portion of the substrate 11 through the opening 16 a formed in the interlayer insulating film 16. Connected to the impurity region 11B. Here, the wiring layer 17 is formed so as to completely or partially surround the MEMS structure 10X corresponding to the opening 16a.

  In the figure, the wiring layer 17 is formed so as to exist only in a portion surrounding the MEMS structure 10X in a plane, but in general, a part of the wiring layer constituting a part of a semiconductor circuit (not shown). Are formed simultaneously with other wiring patterns so as to be the wiring layer 17.

  Thereafter, as shown in FIG. 1C, an interlayer insulating film 18 is further formed on the interlayer insulating film 16 and the wiring layer 17, and an opening exposing a part of the wiring layer 17 is formed in the interlayer insulating film 18. A portion 18a is formed. The opening 18a is also formed so as to completely or partially surround the MEMS structure 10X. A wiring layer 19 is further formed on the interlayer insulating film 18 and is electrically connected to the wiring layer 17 through the opening 18a. The wiring layer 19 has a covering portion 19X disposed above the MEMS structure 10X, and a plurality of pores 19a are formed in the covering portion 19X. The covering portion 19 </ b> X and the pores 19 a of the wiring layer 19 are formed simultaneously with the patterning of the wiring layer 19.

  Thereafter, as shown in FIG. 1D, a surface protective film 20 is formed on the interlayer insulating film 18 and the wiring layer 19. The surface protective film 20 can be composed of a silicon nitride film, a resist or other resin film. The material constituting the surface protective film 20 may be any material having resistance to an etching process performed in a release process described later. In the surface protective film 20, an opening 20a is formed above the MEMS structure 10X. By forming the opening 20a, the covering portion 19X is exposed.

  Then, the interlayer insulating film 18 and the interlayer insulating film 16 on the MEMS structure 10X and the sacrificial layer 12B adjacent to the MEMS structure 10X through the opening 20a of the surface protective film 20 and the pores 19a of the covering portion 19X. A release process is performed to remove the. This release step can be performed by, for example, wet etching using buffered hydrofluoric acid as an etching solution, or dry etching using hydrofluoric acid gas. Thereby, the MEMS structure 10X is arranged in a state where the movable portion 14b is movable in the cavity portion 10C. Thereafter, the cavity 10C is cleaned as necessary.

  Further, after the cavity portion 10C is formed as described above, the sealing layer 21 is formed on the covering portion 19X by a coating method, a vapor deposition method, a sputtering method, a CVD method, or the like. 19a is closed. Thereby, the cavity 10C is sealed. The cavity 10C may be in a state where the pressure is reduced from the atmospheric pressure, or may be in a state in which a gas different from the atmosphere (for example, nitrogen gas) is enclosed. By forming the sealing layer 21 by a vapor deposition method such as a vapor deposition method, a sputtering method, or a CVD method, the reduced pressure state of the cavity 10C can be realized as it is.

  2A is a partial plan view for explaining the substrate dicing step after the step shown in FIG. 1E of this embodiment, and FIG. 2B shows the configuration of the electronic device 10 after the substrate dicing step. It is a longitudinal cross-sectional view. In the present embodiment, the substrate 11 is diced in a state where the cavity 10C is closed by the covering portion 19X and the sealing layer 21 in a state where the MEMS structure 10X is disposed in the cavity 10C as described above. At this time, the substrate 11 is electrically connected to a base of a dicing apparatus (not shown) or the like, and is in a state where a ground potential or other constant potential is applied. In the illustrated example, the substrate 11 is diced along the dicing lines 11x and 11y, whereby a plurality of rectangular chip-shaped electronic devices 10 are formed. As shown in FIG. 2, the MEMS device 10 </ b> X disposed in the above-described cavity 10 </ b> C is formed in the electronic device 10. The cavity 10 </ b> C is surrounded and defined by the element surrounding structure 10 </ b> P configured by the wiring layers 17 and 19, the covering portion 19 </ b> X, and the sealing layer 21. This element surrounding structure 10P is provided with an opening 10Pa partially missing.

  An electrode wiring 13 x is connected to the fixed electrode 13 of the MEMS structure 10 X, and an electrode wiring 14 x is connected to the movable electrode 14. These electrode wirings 13x and 14x are drawn out of the element surrounding structure 10P through the opening 10Pa.

  In the electronic device 10, a semiconductor circuit 10S connected to the MEMS structure 10X is formed. The semiconductor circuit 10S includes a circuit portion that is conductively connected to the electrode wirings 13x and 14x. The semiconductor circuit 10S has circuit elements such as active elements such as MOS transistors, capacitors, inductors, resistors, diodes, wirings, and the same components as those shown in FIG. 1 are formed at the same time. For example, an inter-element isolation film or other surface insulating film is formed together with a surface insulating film (not shown) formed on the substrate 11, a well region or a contact region is formed together with the impurity regions 11A and 11B, a fixed electrode 13 or a movable electrode 14 is formed with a gate electrode, a capacitor electrode, a wiring layer, etc., and a sacrificial layer 12B and interlayer insulating films 16, 18 are formed with a gate insulating film, a capacitive dielectric layer, an interlayer insulating film, etc. An internal wiring layer is formed. The illustrated terminal 10T is an external terminal of the semiconductor circuit 10S.

  In the above embodiment, the wiring layers 17 and 19 and the covering portion 19X constituting the element surrounding structure 10P are made of a conductor, and in some cases, the sealing layer 21 is also made of a conductor. Since these conductors are grounded by being conductively connected to the substrate 11 through the wiring layers 17 and 19 which are wiring structures, the MEMS structure 10X is electromagnetically shielded and the surrounding interlayer insulating films 16 and 18 are also shielded. It has a function of releasing static electricity when is charged. For this reason, it is possible to reduce the electrical influence on the MEMS structure 10X due to the charging of the interlayer insulating films 16 and 18 that occurs when dicing is performed along the dicing lines 11x and 11y in the substrate dicing process described above. For example, bending deformation and breakage of the movable portion 14b due to static electricity can be prevented.

  In particular, in the present embodiment, as shown in FIG. 2A, the openings 10Pa of the wiring layers 17 and 19 which are conductors of the element surrounding structure 10P are formed only on the side of the adjacent semiconductor circuit 10S. Since all the directions are surrounded by the wiring layers 17 and 19, the space between the periphery of the MEMS structure 10X and the outer edge of the electronic device 10 is completely surrounded by the conductor except for the semiconductor circuit 10S. Therefore, the influence of charging caused by friction during dicing can be avoided in almost all directions.

  Further, in the present embodiment, as shown in FIG. 2B, the covering portion 19X that covers the MEMS structure 10X from the upper part of the element surrounding structure 10P (also the sealing layer 21 in some cases) is configured by a conductor. As a result, charging that generates an electric field in the thickness direction with respect to the MEMS structure 10X is prevented in particular, so that an electrostatic influence is exerted on the movable portion 14b disposed to face the fixed electrode 13 in the thickness direction. Can be reduced.

  In the present embodiment, the wiring layers 17 and 19 constitute a conductor of the element surrounding structure 10P that surrounds and defines the cavity portion 10C, and a covering portion 19X that is a conductor of the element surrounding structure 10P (in some cases) Constitutes a wiring structure for electrically connecting the sealing layer 21) to the substrate 11. However, the present invention is not limited to such an embodiment, and at least a part of the element surrounding structure 10P may be formed of a conductor, and the conductor may be configured to be electrically connectable to some potential by the wiring structure. .

[Second Embodiment]
Next, an electronic device 10 'according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and descriptions of those parts and the same manufacturing method are omitted.

  In the present embodiment, the wiring layers 17 'and 19' are provided with conductive side wall portions 17Y and 19Y constituting the element surrounding structure 10P, and wiring portions 17Z and 19Z provided separately from the conductive side wall portions 17Y and 19Y, respectively. This is different from the first embodiment. The conductive side wall portions 17Y and 19Y are basically configured to surround the MEMS structure 10X in the same manner as the wiring layers 17 and 19 of the first embodiment. The wiring layer 19 ′ is provided with a covering portion 19X similar to that of the first embodiment.

  The wiring portions 17Z and 19Z are conductively connected to the covering portion 19X and the conductive side wall portions 17Y and 19Y, and separately from the conductive side wall portions 17Y and 19Y, the conductive portions surrounding the MEMS structure 10X in a plane. Provided outside the side wall portions 17Y and 19Y and conductively connected to an impurity region 11B ′ formed in the surface layer portion of the substrate 11 through the interlayer insulating films 16 and 18. The wiring parts 17Z and 19Z are formed so as to surround the MEMS structure 10X in a plane on the outer side of the conductive side wall parts 17Y and 19Y.

  In the case of the illustrated example, the wiring layer 19 ′ is planarly projected outside the covering portion 19X covering the upper portion of the MEMS structure 10X as indicated by a two-dot chain line, and the wiring portion 17Z is directed downward from the projected portion. 19Z extends to reach the surface of the substrate 11. Needless to say, the protruding portion may be integrated with the covering portion 19X.

  A semiconductor circuit 10S similar to that of the first embodiment is provided adjacent to the cavity 10C that accommodates the MEMS structure 10X and the element surrounding structure 10P ′ surrounding the cavity 10C. The element surrounding structure 10P ′ includes a semiconductor circuit 10S side. An opening 10Pa 'is opened in the opening. As in the first embodiment, electrode wirings 13x ′ and 14x ′ connected to the MEMS structure 10X are drawn out from the opening 10Pa ′, and are conductively connected to the semiconductor circuit 10S.

  The wiring portions 17Z and 19Z constitute a wiring structure for conductively connecting the covering portion 19X and the conductive side wall portions 17Y and 19Y constituting the conductor of the present invention to the substrate 11. The wiring portions 17Z and 19Z, which are the wiring structures, are adjacent to the MEMS structure 10X, the cavity 10C, and the element surrounding structure 10P ′ in a direction excluding the side where the semiconductor circuit 10S is adjacent, and are planarly surrounded from the direction. Configured as follows. These directions are directions in which the MEMS structure 10X, the cavity 10C and the element surrounding structure 10P ′ are directly adjacent to the dicing lines 11x and 11y.

  Here, the wiring portions 17Z and 19Z are conductively connected to the substrate 11 at a plurality of locations discontinuously distributed along a closed curve that surrounds the element surrounding structure 10P ′ in a plane. However, the wiring portions 17Z and 19Z may be formed continuously along the flat curve and continuously connected to the substrate 11.

  In the illustrated example, the opening 10Pa ′ of the element surrounding structure 10P ′ is opened at a position near the corner on the adjacent side of the semiconductor circuit 10S. However, the present invention is not limited to such a configuration. As long as it is on the side adjacent to 10S, it may be opened at the center of the side as in the first embodiment.

  In the present embodiment, the covering portion 19X and the conductive side wall portions 17Y and 19Y, which are conductors provided in the element surrounding structure 10P ′, are wirings constituted by the wiring portions 17Z and 19Z arranged outside the element surrounding structure 10P ′. Since the structure is conductively connected to the substrate 11, the risk of erosion of the wiring structure due to etching in the above-described release process can be eliminated.

  That is, the conductive side wall portions 17Y and 19Y are originally made of a material (aluminum or the like) that is resistant to the etching process in the release process, but the material may not always have sufficient resistance. The aluminum or aluminum alloy used may be slightly attacked by hydrofluoric acid etching in the release process. Therefore, the conductive side wall portions 17Y and 19Y are eroded depending on the composition of the etchant and the etching time during the release process, and particularly the conductive side wall portion 17Y and the substrate 11 are eroded, so that the conductive connectivity to the substrate 11 is deteriorated. There is also a risk. Therefore, in the first embodiment, it may be assumed that a desired effect cannot be obtained depending on the release process.

  On the other hand, in the present embodiment, wiring portions 17Z and 19Z are separately provided outside the conductive side wall portions 17Y and 19Y, and these wiring portions 17Z and 19Z are not directly exposed to the release process. Such deterioration of the conductive connectivity does not occur.

[Third Embodiment]
Next, an electronic apparatus 10 ″ according to a third embodiment of the present invention will be described with reference to FIG. 4. In the present embodiment, the same reference numerals are given to the same parts as those in the first embodiment, and those parts will be described. The description of the parts and the description of the same manufacturing method will be omitted.

  In the present embodiment, the second embodiment is provided in that a wiring structure including wiring portions 17Z and 19Z is provided on the outer side of the element surrounding structure 10P ″ surrounding the MEMS structure 10X and the cavity portion 10C and is conductively connected to the substrate 11. However, the present embodiment is different in that the main part of the semiconductor circuit 10S ″ is adjacent to both sides of the MEMS structure 10X, the cavity 10C, and the element surrounding structure 10P ″. The peripheral structure 10P ″ is also different in that openings 10Pa ″ for drawing out the electrode wirings 13x ″ and 14x ″ are opened on both sides adjacent to the semiconductor circuit 10S ″.

  In the present embodiment, the main parts of the semiconductor circuit 10S ″ are adjacent to each other in two directions on both sides of the element surrounding structure 10P ″ surrounding the MEMS structure 10X and the cavity part 10C, and correspondingly, the main part of the semiconductor circuit 10S ″ Wiring portions 17Z and 19Z are arranged in the remaining two directions except for the two adjacent directions, and in the illustrated example, these wiring portions 17Z and 19Z surround the remaining two directions. Conductive connection is made with the substrate 11 at a plurality of discontinuous locations, and the conductive connection portion extended continuously may be formed as described above.

  The wiring layer 19 ″ provided with the covering portion 19X covering the MEMS structure 10X extends in the remaining two directions, and the wiring portions 17Z and 19Z are formed below the protruding portions.

  In the present embodiment, as shown in the illustrated example, the circuit portions of the semiconductor circuit 10S ″ are adjacent to each other in two directions on both sides of the MEMS structure 10X, the cavity portion 10C, and the element surrounding structure 10P ″, and the semiconductor circuit 10S also in the remaining two directions. Although there is a region in which "" wirings and the like are arranged, the region is very small. However, the semiconductor circuit 10S "may be composed of only the two circuit portions. Since the wiring portions 17Z and 19Z, which are wiring structures, are conductively connected to the substrate 11 outside the remaining two directions, the charging caused by friction along the dicing line 11x is the same as in the above embodiments. The influence can be reduced.

[Fourth Embodiment]
Finally, an electronic device 30 according to a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and descriptions of those parts and the same manufacturing method are omitted.

  In this embodiment, the MEMS structure 10X, the cavity 30C, and the element surrounding structure 30P are the same as those in the first embodiment, but the substrate 31 is an insulating substrate such as ceramics, glass, resin, and the wiring layer 39 is around the element. The difference is that a wiring portion 39V extended outward is provided in addition to the covering portion 39X and the conductive side wall portion 39Y which are conductors of the structure 30P. The wiring portion 39V includes a terminal portion 39W that extends outward on the interlayer insulating film 18 and is exposed at the opening 20b formed in the surface protective film 20. A protruding electrode 39T may be formed on the terminal portion 39W.

  In the present embodiment, apart from the covering portion 39X, the conductive side wall portion 39Y and the wiring layer 17 constituting the conductor in the element surrounding structure 30P, a wiring portion 39V extending to the outside is formed, and this wiring portion 39V is formed. Is configured to be connectable to a predetermined external potential via the terminal portion 39W. For example, the substrate 31 is diced by fixing the protruding electrode 39T indicated by a dotted line in a conductive contact state (electrically grounded) to the base of the dicing apparatus, thereby preventing charging during dicing. The electrical influence on the MEMS structure 10X due to the charging can be reduced.

  Note that the electronic device of the present invention is not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the scope of the present invention. For example, in each of the above embodiments, a MEMS element is illustrated as a functional element, and in particular, in the illustrated example, an electrostatic MEMS vibrator is described as an example. However, other than a microactuator, a pressure sensor, an acceleration sensor, and other MEMS vibrators Or any other functional element other than a MEMS element, such as a crystal resonator, a surface acoustic wave element, or a semiconductor pressure sensor, as long as it is disposed in a cavity on a substrate. It doesn't matter.

Process sectional drawing (a)-(e) which shows the manufacturing process and structure of 1st Embodiment. The partial top view before the board | substrate dicing process of 1st Embodiment (a), and the longitudinal cross-sectional view after a board | substrate dicing process (b). The partial top view before the board | substrate dicing process of 2nd Embodiment (a), and the longitudinal cross-sectional view after a board | substrate dicing process (b). The fragmentary top view (a) before the board | substrate dicing process of 3rd Embodiment, and the longitudinal cross-sectional view (b) after a board | substrate dicing process. The fragmentary top view (a) before the board | substrate dicing process of 4th Embodiment, and the longitudinal cross-sectional view after a board | substrate dicing process (b).

Explanation of symbols

10, 10 ', 10 ", 30 ... electronic device, 10X ... MEMS structure (functional element), 10C, 30C ... cavity, 10P, 10P', 10P", 30P ... element peripheral region, 10 Pa, 10 Pa ', 10 Pa "... opening, 11, 31 ... substrate, 11A, 11B ... impurity region, 12A ... underlying insulating layer, 12B ... sacrificial layer, 13 ... fixed electrode, 14 ... movable electrode, 16, 18 ... interlayer insulating film, 17, 19" , 39 ... wiring layer, 19X, 39X ... covering portion, 17Y, 19Y, 39Y ... conductive side wall portion, 17Z, 19Z, 39V ... wiring portion, 39W ... terminal portion

Claims (7)

In an electronic device comprising a substrate, a functional element disposed on the substrate, and an element surrounding structure that is provided on the substrate and surrounds and defines a cavity in which the functional element is disposed,
An electronic device, wherein at least a part of the element surrounding structure is made of a conductor, and a wiring structure for electrically connecting the conductor is provided.   The electronic device according to claim 1, wherein the conductor covers at least an upper portion of the cavity.   The electronic device according to claim 1, wherein the wiring structure electrically connects the conductor to the substrate.   4. The electronic device according to claim 3, wherein a carrier region having a concentration higher than that of a surrounding substrate portion is provided in a surface layer portion of the substrate to which the wiring structure is conductively connected.   5. The element surrounding structure has a conductive side wall portion constituting at least a part of a side wall of the cavity portion, and the wiring structure is separately provided outside the conductive side wall portion. The electronic device according to any one of the above.   6. The electronic device according to claim 1, further comprising a semiconductor circuit formed on or above the substrate and conductively connected to the functional element. A functional element forming step of forming a functional element on the substrate;
A substrate coating step of forming a substrate coating structure on the substrate and the functional element;
An element exposing step of exposing the functional element by removing a portion of the substrate covering structure on the functional element;
By closing the upper side of the functional element, it is configured together with the remaining part of the substrate covering structure in the element exposing step, surrounding and defining a cavity part in which the functional element is accommodated, and at least a part of which is a conductor. An element closing step for completing an element surrounding structure including a wiring structure configured and electrically connecting the conductor; and
A substrate dicing step for dicing the substrate after the element closing step;
A method for manufacturing an electronic device, comprising:

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