JP5025922B2 - Circuit board, method for manufacturing circuit board, and semiconductor device - Google Patents

Description

  The present invention relates to a circuit board, a circuit board manufacturing method, and a semiconductor device, and more particularly, to a circuit board on which circuit elements are mounted and used as an interposer, a circuit board manufacturing method, and a semiconductor device.

  Conventionally, a circuit device has been formed by mounting a semiconductor element such as an IC chip on a mounting substrate having a conductive path formed on the surface thereof, for example. As a structure for connecting a conductive path on a mounting substrate and a semiconductor element, there are two mounting structures of face-up and face-down (flip chip method).

  When the semiconductor element is mounted on the mounting board face up, the back surface of the semiconductor element is fixed to the mounting board. The pad formed on the upper surface of the semiconductor element and the conductive path of the mounting substrate are wire bonded by a thin metal wire. However, in the connection method using wire bonding, it is necessary to secure a region for forming a fine metal wire in the peripheral portion of the semiconductor element, and thus there is a problem that an area required for mounting the semiconductor element increases.

  When the semiconductor element is mounted on the mounting substrate face down, the pad electrode of the semiconductor element arranged on the lower surface and the conductive path on the mounting substrate are connected using solder bumps or the like. By mounting the semiconductor element face down, the area required for mounting can be made equal to the size of the element. However, since the thermal expansion coefficient is different between the mounting substrate and the semiconductor element, thermal stress acts on the solder bump that joins the two together with the temperature change. This thermal stress causes cracks in the solder bumps, resulting in a problem that the connection reliability of the semiconductor element is lowered.

  In order to solve this problem, a structure for connecting a semiconductor element and a mounting substrate via an interposer having a linear expansion coefficient equivalent to that of a chip has been proposed.

  A semiconductor element connection structure using a circuit board as an interposer will be described with reference to a cross-sectional view of FIG. Here, the semiconductor element 101 which is an LSI chip having a large number of pads is mounted on the mounting substrate 104 via the circuit substrate 100. The pad located on the back surface of the semiconductor element 101 and the circuit board 100 are connected by a connection electrode 102. Further, the conductive path 105 formed on the upper surface of the mounting substrate 104 and the circuit board 100 are connected by the external electrode 103. Furthermore, conductive patterns 106 insulated by an insulating layer 107 are formed on the upper surface and the back surface of the circuit board 100.

When a material having a thermal expansion coefficient closer to that of the semiconductor element 101 than that of the mounting substrate 104 is adopted as the material of the circuit board 100 that is an interposer, the thermal stress adopted in the connection electrode 102 is reduced. Therefore, the connection reliability with respect to the thermal stress of the connection electrode 102 can be improved. As a specific material of the circuit board 100, resin, metal, ceramic, or the like is employed. Patent Document 1 discloses a technique that employs a semiconductor such as silicon as the material of the circuit board 100.
JP 2001-326305 A

  However, in the above-described structure using the circuit board 100, a parasitic capacitance or a voltage drop occurs between the conductive pattern 106 and the circuit board 100, and the malfunction of the semiconductor element 101 may occur due to the ground becoming unstable. was there. Specifically, the circuit board 100 is in a floating state, and the potential is not fixed. Therefore, a potential difference is easily generated between the conductive pattern 106 and the circuit board 100, and a parasitic capacitance is generated between the two. In particular, when the semiconductor element 101 is an element that operates at a high frequency of about several GHz, there arises a problem that the performance of the element deteriorates due to parasitic capacitance generated in the circuit board 100.

  Further, since the circuit board 100 does not take measures against noise, there is a problem that noise transmitted through the circuit board 100 enters the semiconductor element 101 and causes the semiconductor element 101 to malfunction. In particular, when an analog circuit sensitive to noise is formed in the semiconductor element 101, the semiconductor element 101 may malfunction due to noise entering from the outside. Further, there is a problem that noise generated from the semiconductor element 101 is transmitted to the outside through the circuit board 100 and adversely affects other circuit elements. Such a problem also occurs remarkably when the semiconductor element 101 is a high-frequency device.

  Furthermore, since it is necessary to form the conductive pattern 106 connected to the ground potential or the power supply potential on the upper surface of the circuit board 100, there is a problem that it is difficult to reduce the size of the circuit board 100.

  The present invention has been made in view of the above problems, and the main object of the present invention is a circuit board in which connection reliability with a circuit element to be mounted is ensured, and further, parasitic capacitance is reduced and noise countermeasures are taken. An object of the present invention is to provide a circuit board manufacturing method and a semiconductor device.

The circuit board of the present invention includes a first impurity semiconductor substrate connected to either a ground potential or a power supply potential via a first connection electrode, and either a ground potential or a power supply potential via a second connection electrode . A laminated substrate formed by laminating a second impurity semiconductor substrate connected to the other through an insulating layer; a through hole penetrating the laminated substrate; a sidewall of the through hole; and an upper surface and a lower surface of the laminated substrate an insulating film covering said and formed on the side wall of the through hole through said insulating layer through-electrode penetrating through the multilayer substrate, is formed on the upper surface of the first impurity semiconductor substrate through the insulating film And a second conductive pattern formed on the back surface of the second impurity semiconductor substrate with the insulating film interposed therebetween .

Furthermore, the circuit board of the present invention includes a first impurity semiconductor substrate connected to either the ground potential or the power supply potential via the first connection electrode, and the ground potential or the power supply potential via the second connection electrode. A laminated substrate obtained by laminating a second impurity semiconductor substrate connected to one of the other via an insulating layer, a through hole penetrating the laminated substrate, a sidewall of the through hole, and an upper surface of the laminated substrate And an insulating film covering the lower surface, a through electrode penetrating the laminated substrate through the insulating film formed on the sidewall of the through hole, and an upper surface of the first impurity semiconductor substrate through the insulating film A first conductive pattern formed; and a second conductive pattern formed on the back surface of the second impurity semiconductor substrate via the insulating film, wherein the first connection electrode includes the second impurity Before passing through the semiconductor substrate Formed in the first of said connection hole through said insulating film formed side walls and the upper surface of the first impurity semiconductor substrate extending connecting hole to the impurity semiconductor substrate, said first impurity semiconductor substrate The second connection electrode is electrically connected to the side wall of a connection hole that extends through the first impurity semiconductor substrate to the second impurity semiconductor substrate and the upper surface of the first impurity semiconductor substrate. is formed through the formed the insulating film in the connection hole, wherein the coupled second impurity semiconductor substrate and electrically.

Furthermore, the circuit board of the present invention includes a laminated substrate comprising a first impurity semiconductor substrate and a second impurity semiconductor substrate laminated via an insulating layer, and an insulating film in a through-hole penetrating the laminated substrate in the thickness direction. A through electrode provided via the first impurity semiconductor substrate, a first connection electrode electrically connected to the first impurity semiconductor substrate, a second connection electrode electrically connected to the second impurity semiconductor substrate, A conductive pattern formed on a surface of an insulating film covering the laminated substrate, the first impurity semiconductor substrate is connected to a power supply potential, the second impurity semiconductor substrate is connected to a ground potential, The conductive pattern includes a ground pattern connected to a ground potential and a power pattern connected to a power supply potential, and the power pattern is connected to the first impurity semiconductor substrate via the first connection electrode. , The ground pattern, characterized in that it is connected to the second impurity semiconductor substrate through the second connection electrode.

Further, the circuit board manufacturing method of the present invention includes a step of preparing a laminated substrate in which a first impurity semiconductor substrate and a second impurity semiconductor substrate are laminated via an insulating layer, and one main surface of the laminated substrate. Forming a first opening and a second opening having different opening diameters in the etching mask, etching the laminated substrate through the etching mask, and forming the first semiconductor substrate at the bottom said second semiconductor substrate so as to form a second connection hole exposed from the first opening to form a through hole passing through the multilayer substrate from the second opening portion but the first connection hole and the bottom exposed a step, through the first connecting hole and the second connection hole and the through hole insulating film formed on the upper surface and the back surface of the laminate substrate from a side wall of said first connection hole, Oyo said second connection hole The interior of the through hole, wherein the conductive material is formed on the upper surface and the back surface of the laminated substrate, the first of the first connection electrode connected to the impurity semiconductor substrate, the second connection connected to said second impurity semiconductor substrate Forming a first conductive pattern and a second conductive pattern on an upper surface and a rear surface of the multilayer substrate, and forming the first impurity semiconductor substrate via the first connection electrode. Is connected to either the ground potential or the power supply potential, and the second impurity semiconductor substrate is connected to either the ground potential or the power supply potential via the second connection electrode .

Further, the circuit board manufacturing method of the present invention includes a step of preparing a laminated substrate in which a first impurity semiconductor substrate and a second impurity semiconductor substrate are laminated via an insulating layer, and one main surface of the laminated substrate. And forming a first opening, a second opening, and a third opening having different opening diameters in the etching mask, etching the laminated substrate through the etching mask, and Forming a first connection hole from which the first impurity semiconductor substrate is exposed from the first opening, and forming a second connection hole from which the second impurity semiconductor substrate is exposed at the bottom from the second opening; Forming a through hole penetrating the multilayer substrate from the third opening, and insulating films formed on the upper surface and the rear surface of the multilayer substrate from the side walls of the first connection hole, the second connection hole, and the through hole. Through A first connection electrode electrically conductively connected to the first impurity semiconductor substrate by forming a conductive material on the inside of the first connection hole, the second connection hole and the through-hole, on the top surface and the back surface of the multilayer substrate; Forming a second connection electrode and a through electrode electrically connected to the second impurity semiconductor substrate, and forming a first conductive pattern and a second conductive pattern on an upper surface and a back surface of the multilayer substrate. The first impurity semiconductor substrate is connected to either the ground potential or the power supply potential via the first connection electrode, and the second impurity semiconductor substrate is connected to the ground potential or the power supply potential via the second connection electrode. It is characterized by being connected to either one of the power supply potentials .

Furthermore, a semiconductor device according to the present invention includes the above circuit board and a semiconductor element fixed to the main surface of the circuit board.

  According to the present invention, since the connection electrode penetrating the stacked first semiconductor substrate or the second semiconductor substrate is provided, the potential of each semiconductor substrate stacked through the connection electrode can be taken out at an arbitrary location.

  Furthermore, according to the circuit board of the present invention, by providing the first connection electrode and the second connection electrode that are electrically connected to the stacked first semiconductor substrate and second semiconductor substrate, the first semiconductor substrate and the second connection electrode are provided. 2 The potential of the semiconductor substrate can be fixed. Therefore, parasitic capacitance generated between the multilayer substrate and the conductive pattern formed on the surface can be reduced.

  Furthermore, according to the present invention, the first semiconductor substrate is set to the ground potential and the second semiconductor substrate is set to the power supply potential, so that the first semiconductor substrate is formed on the surface of the multilayer substrate via the first connection electrode and the second connection electrode. The conductive pattern thus formed can be connected to a ground potential or a power supply potential at an arbitrary position. Therefore, since it is not necessary to draw the conductive pattern connected to the ground potential or the power supply potential on the surface of the laminated substrate, the wiring density of the conductive path can be suppressed and the delay due to signal propagation can be suppressed. In addition, the suppression of the wiring density can secure an area necessary for timing adjustment such as equal-length wiring, and an electric circuit with higher reliability can be realized. Further, since the first semiconductor substrate and the second semiconductor substrate function as conductive paths in which the entire substrate is connected to the ground potential or the power supply potential, the ground impedance and the power supply impedance can be reduced.

  Furthermore, the shielding effect of the circuit board can be improved by setting the first semiconductor substrate to the ground potential and the second semiconductor substrate to the power supply potential. Therefore, it is possible to block external noise and stabilize the operation of the circuit element mounted on the circuit board.

  According to the manufacturing method of the present invention, an etching mask having a plurality of openings having different opening diameters is used to etch a stacked substrate in which a first semiconductor substrate and a second semiconductor substrate are stacked via an insulating layer. Yes. Thereby, the connection hole through which the first semiconductor substrate or the second semiconductor substrate is exposed from the bottom and the through hole penetrating the laminated substrate can be formed simultaneously. Accordingly, the circuit board can be formed by simplifying the etching process.

  In addition, by providing the above-described etching mask with the first opening, the second opening, and the third opening having different opening diameters, three holes having different depths can be formed in the laminated substrate. Specifically, a first connection hole extending from the first opening having the smallest opening diameter to the middle of the thickness direction of the first semiconductor substrate is formed. Next, a second connection hole that extends from the second opening having a small opening diameter to the second semiconductor substrate through the first semiconductor substrate and the insulating layer is formed. A through hole penetrating the entire laminated substrate is formed from the third opening having the largest opening diameter. Therefore, the etching process can be further simplified.

<First embodiment>
In this embodiment, the structure of a circuit board will be described with reference to FIGS.

  With reference to FIG. 1, a basic configuration of a circuit board 10 serving as an interposer will be described. 1A, 1B, and 1C are cross-sectional views of the circuit board 10. FIG.

  With reference to FIG. 1A, in the circuit board 10 of the present embodiment, a laminated substrate 11 is formed from a first semiconductor substrate 11A and a second semiconductor substrate 11B that are laminated via an insulating layer 11C. Furthermore, a through electrode 13 that penetrates the multilayer substrate 11, a connection electrode 16 that is electrically connected to the first semiconductor substrate 11A, and a connection electrode 17 that is electrically connected to the second semiconductor substrate 11B are formed. Further, a first conductive pattern 14 and a second conductive pattern 15 are formed on the upper surface and the back surface of the multilayer substrate 11. In this embodiment, the circuit board 10 is used as an interposer. An interposer is a substrate that is located between a circuit element such as a semiconductor element and a mounting substrate and is used to configure a circuit device or the like.

  The laminated substrate 11 is formed of a first semiconductor substrate 11A and a second semiconductor substrate 11B that are bonded together via an insulating layer 11C. As a material of the laminated substrate 11, a bonded SOI (Silicon On Insulator) substrate can be employed. The thickness of the multilayer substrate 11 is, for example, about 100 μm to 200 μm.

  The first semiconductor substrate 11A is made of a semiconductor such as silicon having a thickness of about 50 μm to 100 μm. As the material of the first semiconductor substrate 11A, an intrinsic semiconductor or an impurity semiconductor can be employed. As the impurity semiconductor, a P-type semiconductor into which a P-type impurity such as boron is introduced, or an N-type semiconductor into which an N-type impurity such as phosphorus is introduced is employed. In particular, when an impurity semiconductor substrate is employed as the first semiconductor substrate 11A, the electrical conductivity and thermal conductivity of the first semiconductor substrate 11A are increased, and the function of the metal substrate is approached. That is, the first semiconductor substrate 11A can have various functions such as a shield function and a heat dissipation function. Further, when the ground wiring is provided, the ground wiring and the first semiconductor substrate 11A can be set at the same potential, and it is possible to eliminate the parasitic capacitance in the ground wiring. By using the impurity semiconductor as the material of the first semiconductor substrate 11A, the electrical resistance of the first semiconductor substrate 11A can be lowered, and conduction with the connection electrode 16 can be facilitated.

  The second semiconductor substrate 11B is made of the same material as the first semiconductor substrate 11A described above, and is stacked with the first semiconductor substrate 11A via the insulating layer 11C. A laminated substrate 11 is formed from the laminated first semiconductor substrate 11A and second semiconductor substrate 11B. The thickness of the second semiconductor substrate 11B may be the same as that of the first semiconductor substrate 11A.

  The first semiconductor substrate 11A and the second semiconductor substrate 11B described above can be connected to a ground potential or a power supply potential. In this case, the first semiconductor substrate 11A may be connected to the ground potential and the second semiconductor substrate 11B may be connected to the power supply potential, or the first semiconductor substrate 11A may be connected to the power supply potential and the second semiconductor substrate 11B may be connected to the power supply potential. It may be connected to a ground potential.

The insulating layer 11C is made of an insulating material such as SiO ₂ or a resin film, and has a function of bonding the first semiconductor substrate 11A and the second semiconductor substrate 11B and insulating them.

  Furthermore, the circuit board 10 of this embodiment made of silicon is made of the same material as that of a semiconductor element such as an LSI chip. Therefore, since the thermal expansion coefficient of the semiconductor element to be mounted is equal to the thermal expansion coefficient of the circuit board 10, the connection reliability between them can be improved. For example, when the semiconductor element is mounted face-up on the circuit board 10, since the connection is made using a connection means such as a fine metal wire or a lead plate, the reliability of the connection portion between the connection means and the semiconductor element is improved. Considering the case where the semiconductor element is mounted on the upper surface of the circuit board 10 by using the bump electrode by using the bump electrode, the thermal stress acting on the bump electrode connecting the both becomes extremely small, and the connection reliability is improved. .

  The insulating film 12 is made of a resin film such as a silicon oxide film, a silicon nitride film, or polyimide, and covers the upper surface and the back surface of the multilayer substrate 11. The insulating film 12 insulates the first conductive pattern 14 and the second conductive pattern 15 from the laminated substrate 11. The side surface of the through hole 23 is also covered with the insulating film 12. Further, the side surfaces of the connection holes 27 and 32 are covered with the insulating film 12, and the bottom surface is not covered with the insulating film 12 because the semiconductor substrate is exposed.

  The first conductive pattern 14 and the second conductive pattern 15 are formed on the top surface and the back surface of the multilayer substrate 11. These conductive patterns are made of a metal whose main material is copper (Cu), aluminum (Al), or gold (Au). The first conductive pattern 14 is formed on the upper surface of the multilayer substrate 11 and forms pads (for example, die pads or bonding pads) to which semiconductor elements are connected, wirings for connecting the pads, and the like. The second conductive pattern 15 extends to the back surface of the multilayer substrate 11 and forms pads used for connection to a mounting substrate and the like, wiring for connecting these pads, and the like.

  Here, the first conductive pattern 14 and the second conductive pattern 15 of a single layer are formed, but these conductive patterns can be formed in multiple layers.

  The through electrode 13 is made of a conductive material provided in a through hole 23 provided through the laminated substrate 11 in the thickness direction. The first conductive pattern 14 and the second conductive pattern 15 are connected by the through electrode 13. The through electrode 13 and the laminated substrate 11 are insulated by an insulating film 12 provided on the inner wall of the through hole 23. The through electrode 13 can be formed by, for example, a metal film that is formed by a plating method described later and is electrically connected to the first conductive pattern 14 and the second conductive pattern 15. Here, a through electrode 13 made of a metal film having a thickness of about several μm is formed on the inner wall of the through hole 23 having a width of about 40 μm. Further, the through electrode 13 may be made of a conductive material completely embedded in the through hole 23.

  The connection electrode 16 is an electrode formed from the upper surface of the multilayer substrate 11 and electrically connected to the first semiconductor substrate 11A. With the connection electrode 16, the first conductive pattern 14 formed on the upper surface of the multilayer substrate 11 and the first semiconductor substrate 11 </ b> A in the upper layer can be electrically connected. Specifically, the connection electrode 16 is made of a conductive material embedded in the connection hole 32 extending partway in the thickness direction of the first semiconductor substrate 11A. The bottom of the connection electrode 16 is in ohmic contact with the first semiconductor substrate 11A exposed at the bottom of the connection hole 23, whereby the connection electrode 16 and the first semiconductor substrate 11A are electrically connected. The width of the connection electrode 16 is preferably equal to or less than that of the through electrode 13 and is set to about 40 μm to 10 μm, for example. The depth of the connection electrode 16 may be as long as it does not penetrate the first semiconductor substrate 11A, and is, for example, about 50 μm. The connection electrode 16 can be formed of a metal film that is formed integrally with the first conductive pattern 14. Here, a conductive material is embedded in the connection hole 32 to form the connection electrode 16. The connection electrode 16 may be of a type in which the connection hole 32 is completely embedded, or may be of a type made of a metal film deposited on the side wall of the connection hole 32.

  The connection electrode 17 is an electrode that is formed from the lower surface of the multilayer substrate 11 and is electrically connected to the lower second semiconductor substrate 11B. The connection electrode 17 electrically connects the second conductive pattern 15 formed on the lower surface of the multilayer substrate 11 and the lower second semiconductor substrate 11B. Specifically, the connection electrode 17 is made of a conductive material embedded in the connection hole 27 extending partway in the thickness direction of the second semiconductor substrate 11B. The basic configuration of the connection electrode 17 is the same as that of the connection electrode 16 described above.

  In the present embodiment, the first semiconductor substrate 11A can be connected to the ground potential or the power supply potential via the connection electrode 16 described above. Further, the second semiconductor substrate 11B can be connected to the ground potential or the power supply potential via the connection electrode 17. Furthermore, the ground potential or the power supply potential can be taken out at an arbitrary position of the multilayer substrate 11 via the connection electrode 16 and the connection electrode 17. Details of this matter will be described later with reference to FIG.

  Here, in FIG. 1A, a two-layer semiconductor substrate composed of a first semiconductor substrate 11A and a second semiconductor substrate 11B is stacked. However, three or more semiconductor substrates are stacked, and the semiconductor substrates of the respective layers are stacked. You may connect to a different electric potential.

  With reference to FIG. 1 (B), the circuit board 10 from which the shape of the connection electrodes 16 and 17 differs is demonstrated. Here, the connection electrode 16 is connected to the second semiconductor substrate 11B, and the connection electrode 17 is connected to the first semiconductor substrate 11A.

  The connection electrode 16 extends from the upper surface of the multilayer substrate 11 through the first semiconductor substrate 11A and the insulating layer 11C to the second semiconductor substrate 11B. In other words, the connection electrode 16 is formed in the connection hole 32 that extends from the upper surface of the multilayer substrate 11 through the first semiconductor substrate 11A and the insulating layer 11C to the middle of the second semiconductor substrate 11B. The end of the connection electrode 16 is in contact with the second semiconductor substrate 11B exposed at the bottom of the connection hole 32. The connection electrode 16 and the first semiconductor substrate 11 </ b> A are insulated from each other by the insulating film 12 formed on the side wall of the connection hole 32. By forming the connection electrode 16 having such a shape, the first conductive pattern 14 formed on the upper surface of the multilayer substrate 11 and the second semiconductor substrate 11B in the lower layer can be connected at an arbitrary position.

  The connection electrode 17 extends from the lower surface of the multilayer substrate 11 to the first semiconductor substrate 11A through the second semiconductor substrate 11B and the insulating layer 11C. The basic configuration of the connection electrode 17 is the same as that of the connection electrode 16 described above. That is, the end portion of the connection electrode 17 is in contact with the upper first semiconductor substrate 11A. Further, the connection electrode 17 is formed inside the connection hole 27, and the connection electrode 17 and the second semiconductor substrate 11B are insulated by the insulating film 12 covering the inner wall of the connection hole 27. With the connection electrode 17, the first semiconductor substrate 11 </ b> A located in the upper layer and the second conductive pattern 15 formed on the lower surface of the multilayer substrate 11 can be electrically connected at an arbitrary location.

  With reference to FIG. 1C, a configuration of still another form of the circuit board 10 will be described. Here, the connection electrodes 16 and 17 extend from the upper surface of the multilayer substrate 11 to the inside.

  The connection electrode 16 extends from the upper surface of the multilayer substrate 11 through the first semiconductor substrate 11A and the insulating layer 11C to the second semiconductor substrate 11B. The configuration of the connection electrode 16 is the same as that in the case of FIG.

  The connection electrode 17 is formed from the upper surface of the multilayer substrate 11 similarly to the connection electrode 16, and is connected to the first semiconductor substrate 11A. Here, the connection electrode 17 is formed shallower than the connection electrode 16, and the tip thereof stops in the middle of the first semiconductor substrate 11 </ b> A.

  By providing the connection electrodes 16 and 17 on the upper surface of the multilayer substrate 11, the first conductive pattern 14 formed on the surface of the multilayer substrate 11 can be connected to the first semiconductor substrate 11A or the second semiconductor substrate 11B at an arbitrary position. It becomes possible to connect. Therefore, when the first semiconductor substrate 11A and the second semiconductor substrate 11B are connected to the ground potential or the power supply potential, the first conductive pattern is formed at any location on the multilayer substrate 11 via the connection electrodes 16 and 17. 14 can be connected to a ground potential or a power supply potential.

  Advantages of providing the connection electrodes 16 and 17 will be described. For example, referring to FIG. 1A, by electrically connecting the first conductive pattern 14 and the first semiconductor substrate 11A via the connection electrode 16, the first conductive pattern 14 and the first semiconductor substrate 11A are connected to each other. Parasitic capacitance generated between them can be reduced. Specifically, the first conductive pattern 14 is formed on the upper surface of the first semiconductor substrate 11 </ b> A via the insulating film 12. In other words, the insulating film 12 as a dielectric is located between the first conductive pattern 14 and the first semiconductor substrate 11A. Accordingly, when the potentials of the first conductive pattern 14 and the first semiconductor substrate 11A are different, parasitic capacitance corresponding to the potential difference is generated. Therefore, in the present embodiment, the first semiconductor substrate 11A and the first conductive pattern 14 are electrically connected via the connection electrode 16, thereby making the potentials of both equal and suppressing the generation of parasitic capacitance. . By reducing the parasitic capacitance, malfunction of the circuit element mounted on the circuit board 10 can be prevented. The same applies to the second semiconductor substrate 11 </ b> B and the second conductive pattern 15 connected via the connection electrode 17.

  Further, when the first semiconductor substrate 11A is fixed to the ground potential, the parasitic capacitance generated between the first conductive pattern (GND line) 14 connected to the ground potential and the first semiconductor substrate 11A is eliminated. Furthermore, when the first semiconductor substrate 11A is connected to the ground potential, the potential of the first semiconductor substrate 11A can be always fixed to the same potential (0V), and thus the potential of the first semiconductor substrate 11A is prevented from fluctuating. You can also Further, a power supply potential (Vcc) may be employed instead of the ground potential.

  Furthermore, since a grouped area of the multilayer substrate 11 can be set to the ground potential, the shielding effect is improved and the propagation of noise transmitted through the circuit board 11 is prevented. In particular, if the entire laminated substrate 11 is dropped to GND, it is effective in absorbing and blocking noise.

  Next, a detailed structure of the connection electrode and the through electrode will be described with reference to FIG.

  Referring to FIG. 2A, the connection electrode 16 is connected to the first semiconductor substrate 11A through the barrier film 35. By forming the barrier film 35, it is possible to prevent copper (Cu), which is the material of the connection electrode 16, from diffusing into the first semiconductor substrate 11A made of silicon. As the material of the barrier layer 35, a refractory metal such as titanium (Ti), titanium nitride (TiN), titanium tungsten (TiW), tantalum nitride (TaN), or a compound containing a refractory metal is employed. Further, the barrier film 35 is formed on the connection electrode 17 and the through electrode 13 shown in FIG.

  With reference to FIG. 2B, the structure of the through electrode 13 will be further described. Here, a recess 24 is formed on the inner wall near the lower end of the through hole 23 from the inner wall to the inside of the multilayer substrate 11. This structure is formed by over-etching the inner wall of the through hole 23. The through hole 23 in the portion where the recess 24 is provided is wider than the other portion. By forming the through electrode 13 inside the through hole 23 so as to fill the recess 24, an anchor effect is generated between the through electrode 13 and the inside of the through hole 23, and the through electrode 13 is formed on the laminated substrate. 11 is difficult to peel off.

  Referring to FIG. 2C, the connection electrode 16 does not necessarily extend in the thickness direction of the first semiconductor substrate 11A, and may have a structure such as a contact employed in a normal semiconductor process. That is, the connection electrode 16 may be formed in the connection hole 32 having a depth enough to remove only the insulating film 12. Even in such a structure, since the connection electrode 16 is in contact with the first semiconductor substrate 11A, the first conductive pattern 14 and the first semiconductor substrate 11A can be connected via the connection electrode 16.

  With reference to FIG. 3, the structure of the circuit board 10 of another form is demonstrated. In the circuit board 10 shown in this figure, description will be made assuming that the upper first semiconductor substrate 11A is connected to the power supply potential and the lower second semiconductor substrate 11B is connected to the ground potential. Here, the upper first semiconductor substrate 11A may be connected to the ground potential, and the lower second semiconductor substrate 11B may be connected to the power supply potential.

  In the circuit board 10 of this embodiment, the first conductive pattern 14 formed on the upper surface of the multilayer substrate 11 is connected to a signal pattern 14A through which a control signal or the like passes, a ground pattern 14B connected to the ground potential, and a power source. Power supply pattern 14C. The ground pattern 14B and the power supply pattern 14C are connected to the ground potential or the power supply potential via the first semiconductor substrate 11A, the second semiconductor substrate 11B, and the connection electrodes.

  Connection electrodes 16 and 51 are formed from the upper surface of the multilayer substrate 11. The connection electrode 16 extends from the upper surface of the multilayer substrate 11 through the first semiconductor substrate 11A and the insulating layer 11C to the lower second semiconductor substrate 11B. Therefore, the lower second semiconductor substrate 11B whose potential is fixed to the ground potential can be connected to the ground pattern 14B via the connection electrode 16. On the other hand, the connection electrode 51 extends from the upper surface of the multilayer substrate 11 to the first semiconductor substrate 11A. Therefore, the upper first semiconductor substrate 11 </ b> A whose potential is fixed to the power supply potential can be connected to the power supply pattern 14 </ b> C via the connection electrode 51.

  Connection electrodes 17 and 52 are formed from the lower surface of the multilayer substrate 11. The connection electrode 17 extends from the lower surface of the multilayer substrate 11 through the second semiconductor substrate 11B and the insulating layer 11C to the upper first semiconductor substrate 11A. Therefore, the first semiconductor substrate 11A can be connected to the power supply potential located outside via the connection electrode 17. The connection electrode 52 extends from the lower surface of the multilayer substrate 11 to the second semiconductor substrate 11B. Therefore, the second semiconductor substrate 11B can be connected to the ground potential located outside via the connection electrode 52. Here, the second conductive pattern 15 located on the lower surface of the multilayer substrate 11 can be connected to the ground potential or the power supply potential via the connection electrodes 17 and 52.

  With the configuration of the present embodiment described above, the power supply pattern 14 </ b> C can be connected to the first semiconductor substrate 11 </ b> A whose potential is fixed to the power supply potential at any location of the multilayer substrate 11 via the connection electrode 51. Furthermore, the ground pattern 14 </ b> B can be connected to the second semiconductor substrate 11 </ b> B whose potential is fixed to the ground potential via the connection electrode 16. Accordingly, since it is not necessary to route the power supply pattern 14C and the ground pattern 14B on the surface of the multilayer substrate 11, the wiring density on the surface of the circuit substrate 11 can be suppressed. In addition, since the areas of the power supply pattern 14C and the ground pattern 14B can be reduced, a large area for forming the signal pattern 14A can be secured. Accordingly, it is possible to adjust the timing by wiring the signal pattern 14A with the same length. Furthermore, since the entire surface of the first semiconductor substrate 11A and the second semiconductor substrate 11B can be used as a path connected to the power supply potential or the ground potential, the power supply impedance and the ground impedance can be reduced.

  A circuit device (semiconductor device) in which the circuit board of this embodiment is used as an interposer will be described with reference to FIG. Here, the circuit device 20 is configured by mounting the circuit element 18 on the upper surface of the circuit board 10. The back surface of the circuit board 10 is fixed to a conductive path 31 formed on the upper surface of the mounting board 30 via an external electrode 21 made of a conductive material such as solder.

  The first conductive pattern 14 and the second conductive pattern 15 formed on the top surface and the back surface of the circuit board 10 are covered with a coating layer 22 except for the electrically connected region. On the upper surface of the circuit board 10, the first conductive pattern 14 in a region connected to the circuit element 18 is exposed from the coating layer 22. On the back surface of the circuit board 10, the second conductive pattern 15 where the external electrode 21 is attached is exposed from the coating layer 22.

  The second conductive pattern 15 connected to the connection electrode 17 is connected to the conductive path 31A on the mounting substrate 30 via the external electrode 21A. Accordingly, the first semiconductor substrate 11A is connected to an external ground potential or power supply potential via the connection electrode 17, the external electrode 21A, and the conductive path 31A. Similarly, the second semiconductor substrate 11B is connected to an external power supply potential or ground potential via the connection electrode 52, the external electrode 21B, and the conductive path 31B.

  The circuit element 18 is an element mounted on the circuit board 10 and can generally employ passive elements such as resistors, capacitors, and / or coils, and active elements such as diodes, transistors, ICs, and LSIs. Further, a plurality of circuit elements 18 may be mounted on the circuit board 10 to realize the system function with one circuit device 20A. Sensors such as an optical sensor, a pressure sensor, and a magnetic sensor may be mounted. A transistor or the like may be formed on the surface of the first semiconductor substrate 11A or the second semiconductor substrate 11B by a known diffusion process.

  The semiconductor element 18B is connected to the first conductive pattern 14 formed on the upper surface of the circuit board 10 via the bump electrode 19 by a flip chip method. As described above, the circuit board 10 is made of silicon in the same manner as the material of the semiconductor element. Therefore, since the thermal expansion coefficients of the circuit board 10 and the semiconductor element 18B are equal, the thermal stress acting on the bump electrode 19 that connects them is extremely small, and the connection reliability is improved. In addition, an underfill 36 may be filled between the semiconductor element 18B and the circuit board 10 in order to further improve the connection reliability between them.

  In this embodiment, as described above, since the parasitic capacitance generated in the circuit board is reduced, it is possible to operate on the upper surface of the circuit board 10 without deteriorating the characteristics of the semiconductor element 18B operating at high frequency. . Further, in such a conductive path (micro strip line), dielectric loss can be prevented by matching with a general characteristic impedance at high speed transmission.

  Furthermore, by using an insulating material positioned between the semiconductor element 18B and the circuit board 10 as a low dielectric material, it is possible to reduce the parasitic capacitance generated between the semiconductor element 18B and the circuit board 10. . Here, the covering layer 22 and the underfill 36 positioned between them are made of black diamond or fluorinated polyimide, which is a low dielectric material, thereby reducing parasitic capacitance and matching characteristic impedance. Yes.

  In addition, unnecessary radiation generated from the wiring of the mounting substrate 30 or the like or unnecessary radiation generated from the semiconductor element 18B can be blocked by the first semiconductor substrate 11A and the second semiconductor substrate 11B. Accordingly, the semiconductor element 18B provided with an analog circuit sensitive to noise can also realize a stable operation.

  With reference to FIG. 4 (B), the structure of the circuit device 20B of another form is demonstrated. In the circuit device 20B, the semiconductor element 18B is mounted on the upper surface of the circuit board 10 in a face-up state. A sealing resin 37 is formed on the upper surface of the circuit board 10 so that the semiconductor element 18B is sealed. Thus, even when the semiconductor element 18B is mounted face-up, the above-described effects can be obtained.

  The back surface of the semiconductor element 18 </ b> B is fixed to the upper surface of the circuit board 10 via the bonding material 26. The electrode formed on the upper surface of the semiconductor element 18 </ b> B is connected to the first conductive pattern 14 through the fine metal wire 25.

  As the bonding material 26 used for fixing the semiconductor element 18B, a low dielectric material is preferable as described above. Thereby, the parasitic capacitance generated between the semiconductor element 18B and the first conductive pattern 14 located therebelow can be reduced.

  Here, in FIG. 4A, as the mounting substrate 30, a glass epoxy substrate, a ceramic substrate, a glass substrate, a metal substrate, a flexible substrate, or the like can be considered. However, considering that the circuit board 10 and the semiconductor element 18B are made of silicon (Si) and the composition ratio of Si is high, the mounting board 30 is preferably a flexible board.

  Furthermore, a stack structure in which a memory chip is employed as the semiconductor element 18B and a plurality of chips are stacked on the upper layer may be used in consideration of expansion of the memory capacity. At this time, if the memory chip is stacked by using a through electrode extending from the front surface of the chip to the back surface of the chip, a compact and highly reliable module can be realized.

<Second Embodiment>
In this embodiment, a method for manufacturing the circuit board 10 having the configuration shown in FIG. 1A will be described with reference to FIGS.

  Referring to FIG. 5A, first, the laminated substrate 11 is prepared, and the upper surface of the laminated substrate 11 is covered with an etching mask 40 provided with an opening.

  The laminated substrate 11 is formed by laminating a first semiconductor substrate 11A and a second semiconductor substrate 11B made of silicon via an insulating layer 11C. As the laminated substrate 11, a bonded SOI (Silicon On Insulator) substrate can be adopted. By laminating the first semiconductor substrate 11A and the second semiconductor substrate 11B having a thickness of about 50 μm to 100 μm, the multilayer substrate 11 having a thickness of about 100 μm to 200 μm is formed. The first semiconductor substrate 11A and the second semiconductor substrate 11B are preferably impurity semiconductors in which impurities are diffused.

  The etching mask 40 generally employs a photoresist, but a silicon oxide film or a silicon nitride film can be employed. When reactive ion etching (RIE) is performed as a later etching method, a silicon oxide film or a resist excellent in etching resistance is preferable. Here, the outer peripheral surface of the multilayer substrate 11 may be covered with an oxide film in advance. An opening 41 and an opening 42 are formed in the etching mask 40.

  From the opening 41, a region where the through hole 23 that penetrates the laminated substrate 11 in the thickness direction is formed is exposed. The planar shape of the opening 41 is, for example, a circle or a rectangle, and its width W1 is, for example, about 40 μm.

  A region where the connection hole 27 is formed is exposed from the opening 42. The width W2 of the opening 42 is narrower than the opening W1, and is, for example, about 10 μm to 20 μm. Furthermore, the width of the opening 42 is preferably less than half that of the opening 41. By doing in this way, the etching rate of the opening part 42 can be made into the half or less of the opening part 41. FIG. Therefore, even if dry etching is performed until the through hole 23 penetrating the multilayer substrate 11 is formed, the connection hole 27 formed from the opening 42 does not reach the insulating layer 11C located at the center in the thickness direction. From this, the tip of the connection hole 27 formed by dry etching can be stopped in the middle of the thickness direction of the first semiconductor substrate 11A.

Referring to FIG. 5B, next, through-hole 23 and connection hole 27 are formed by etching laminated substrate 11 through etching mask 40. As etching performed in this step, dry etching such as plasma etching, sputter etching, RIE, or ECR is employed. For these dry etching, an etching gas containing SF ₆ , O ₂ , C ₄ F _{8 and the} like is used. Here, etching is progressed downward from the upper surface of the multilayer substrate 11. Further, the through hole 23 and the connection hole 27 may be formed by wet etching.

Furthermore, in this embodiment, different etching gases are used when the first semiconductor substrate 11A and the second semiconductor substrate 11B are etched and when the insulating film 11C is etched. When the first semiconductor substrate 11A and the second semiconductor substrate 11B made of silicon are etched, etching can be performed using a mixed gas of CF ₄ and O _{2 or} a mixed gas of CF ₆ and O ₂ . Further, when etching the insulating layer 11C made of an oxide film (SiO ₂ ), etching can be performed using a mixed gas of CF ₄ and H ₂ , CHF ₄ or C ₂ F6, or the like.

However, the first semiconductor substrate 11A, the second semiconductor substrate 11B, and the insulating layer 11C can be etched without changing the etching gas. In this case, dry etching is performed using SiF ₄ and CO.

  In this step, the multilayer substrate 11 is etched through the etching mask 40 until the through hole 23 that penetrates the multilayer substrate 11 in the thickness direction is formed. As described above, since the etching rate of the opening 42 having a small diameter is slow, the connection hole 27 does not reach the lower surface of the first semiconductor substrate 11A. That is, the connection hole 27 extends partway in the thickness direction of the first semiconductor substrate 11.

  In this step, a connection electrode (not shown) for fixing the first semiconductor substrate 11A to a predetermined potential can be formed by stopping the connection hole 27 in the middle of the first semiconductor substrate 11A. Further, by making the sizes of the opening 41 and the opening 42 different, the etching rate in the depth direction is different, and the through hole 23 and the connection hole 27 can be formed by one etching. Therefore, since it is not necessary to form the through hole 23 and the connection hole 27 in separate steps, the manufacturing cost can be reduced. After this step is completed, the etching mask 40 is peeled from the laminated substrate 11.

  Referring to FIG. 5C, next, a connection hole 32 is formed in the second semiconductor substrate 11B. Here, the laminated substrate 11 is shown upside down. That is, the first semiconductor substrate 11 </ b> A located in the lower layer is attached to the support substrate 44 via the adhesive 43. The upper surface of the second semiconductor substrate 11B located in the upper layer is covered with an etching mask 34 provided with an opening 57. The diameter of the opening 57 may be about 10 μm to 20 μm, similar to the opening 42 described above. The connection hole 32 is formed by etching the second semiconductor substrate 11B exposed from the opening 57. The connection hole 32 does not reach the lower surface of the second semiconductor substrate 11B and stops halfway in the thickness direction. After this process is completed, the etching mask 34 is peeled from the laminated substrate 11, and the laminated substrate 11 is separated from the support substrate 44.

  Referring to FIG. 6A, next, an insulating film 12 made of a silicon oxide film, a silicon nitride film, or the like is formed on the surface of the laminated substrate 11 including the inner walls of the connection holes 27, the connection holes 32, and the through holes 23. To do.

  Referring to FIG. 6B, next, the first semiconductor substrate 11A is exposed from the bottom of the connection hole 27 by removing the insulating film 12 covering the bottom of the connection hole 27. For etching the insulating film 12 covering the bottom of the connection hole 27, anisotropic etching is preferable. That is, since the bottom part is etched rather than the side wall of the connection hole 27, only the bottom part can be exposed. Depending on the etching method, the insulating film 12 on the surface of the multilayer substrate 11 may be left, and the insulating film 12 covering the bottom and side walls of the connection hole 27 may be removed. In this way, the contact resistance of the subsequent connection electrode can be greatly reduced. Similarly, the insulating film 12 covering the bottom surface of the connection hole 32 is removed, and the second semiconductor substrate 11 </ b> B is exposed on the bottom surface of the connection hole 32.

  As a method of removing the insulating film 12 covering the bottom of the connection hole 27, an etching mask may or may not be used.

  In the case of using an etching mask, the insulating film 12 formed on the main surface of the multilayer substrate 11 is covered with an etching mask (not shown) and then anisotropic dry etching is performed so that the bottom of the connection hole 27 is positioned. The insulating film 12 to be removed is removed.

  When an etching mask is not used, the following method is preferable. That is, although the thickness of the insulating film 12 is shown uniformly in the drawing, the insulating film 12 formed inside the connection hole 27 is actually thinner than the insulating film 12 formed on the upper surface of the laminated substrate 11. For example, the thickness of the insulating film 12 covering the bottom of the connection hole 27 is about half that of the insulating film 12 formed on the upper surface of the multilayer substrate 11. Accordingly, when dry etching is performed uniformly from the upper surface of the laminated substrate 11 without using an etching mask, the insulating film 12 at the bottom of the connection hole 27 is removed before the insulating film 12 formed on the upper surface of the laminated substrate 11 is removed. Can be removed.

  Referring to FIG. 6C, a metal film 29 made of, for example, copper (Cu) is formed so as to cover the inside of the through hole 23, the connection hole 27 and the connection hole 32, and the upper surface and the back surface of the multilayer substrate 11. .

  Specifically, first, in order to prevent diffusion of copper (Cu), barrier layers are formed on the inner walls of the through holes 23, the connection holes 27 and the connection holes 32, and the upper surface and the back surface of the multilayer substrate 11. This barrier layer is made of titanium (Ti), titanium nitride (TiN), titanium tungsten (TiW), tantalum nitride (TaN), or the like, and is formed by sputtering or CVD. Further, a seed layer made of a metal film having a thickness of about several hundreds of nanometers is formed on the upper surface of the barrier layer by sputtering or CVD, and electrolytic plating is performed by using this seed layer as an electrode. A metal film 29 having a thickness of about several μm is formed. By the metal film 29, the connection electrode 16, the connection electrode 17, and the through electrode 13 are formed.

  Here, the connection holes 27 and 32 are embedded with a metal film. However, as shown in the through hole 23, a thin metal film may be formed on the side walls of the connection holes 27 and 32. In other words, the inner walls of the connection holes 27 and 32 may be covered with a metal film to form a cavity inside.

  Referring to FIG. 6D, next, the first conductive pattern 14 and the second conductive pattern 15 are formed by patterning the metal film 29 formed on the top surface and the back surface of the multilayer substrate 11 by etching or the like. . Further, the first conductive pattern 14 and the second conductive pattern 15 are covered with a coating resin (not shown) except for the electrical connection portion. A circuit board that can be used as an interposer is formed by the above steps.

  Here, the conductive pattern is composed of one layer, but thereafter, the formation of the insulating film, the formation of the conductive material, and the patterning may be repeated several times to form a plurality of stacked conductive patterns.

<Third Embodiment>
In this embodiment, a method for manufacturing a circuit board whose structure is shown in FIG. 1B will be described with reference to FIG. Since the basic manufacturing method of this step is the same as that of the second embodiment described above, the differences will be mainly described.

  With reference to FIG. 7A, first, the connection hole 27, the connection hole 32, and the through hole 23 are formed in the multilayer substrate 11. Specifically, after the connection hole 27 and the through hole 23 are formed from the first semiconductor substrate 11A side, the connection hole 32 is further formed from the second semiconductor substrate 11B side. Here, a state in which the connection hole 32 is formed by using the etching mask 34 after the laminated substrate 11 is attached to the support substrate 44 via the adhesive 43 is shown. The connection hole 27, the connection hole 32, and the through-hole 23 can be formed by dry etching as in the second embodiment.

  In this embodiment, the connection hole 27 and the connection hole 32 are formed through the connection layer 11C. Specifically, the connection hole 27 is formed so as to extend through the first semiconductor substrate 11A and the insulating layer 11C to the second semiconductor substrate 11B. Furthermore, the connection hole 32 is formed so as to extend through the second semiconductor substrate 11B and the insulating layer 11C to the first semiconductor substrate 11A. That is, compared with the second embodiment, the connection hole 27 and the connection hole 32 are formed deeper.

  In order to form the connection holes 27 and 32 deep as described above, two methods are conceivable. The first method is to increase the opening diameter of the opening 57 provided in the etching mask. For example, by increasing the opening diameter of the opening 57 to about 20 to 30 μm, the etching rate is increased and the deeper through-hole 23 can be formed. The second method is a method in which the connection hole 27 and the connection hole 32 are formed deeply by extending the dry etching time.

  Referring to FIG. 7B, next, an insulating film 12 made of a silicon oxide film or a silicon nitride film is formed on the surface of the multilayer substrate 11. Specifically, the upper surface and the back surface of the multilayer substrate 11 are covered with the insulating film 12, and the inner walls of the connection holes 27, the connection holes 32, and the through holes 23 are also covered with the insulating film 12.

  In general, when the insulating film 12 is formed, a film such as a CVD method is generally used. In this case, since the wafer to be the laminated substrate 11 is placed on the wafer table in the chamber, no film is deposited on the back surface. Therefore, in this case, two film forming steps are required for the front and back sides. If the films are formed under substantially the same conditions, the films formed on the side walls of the connection holes 27 and 32 have substantially the same film thickness, and the film thicknesses of the insulating film 12 on the upper surface and the back surface of the laminated substrate 11 are also substantially the same. However, the side wall of the through hole 23 is formed thicker than the connection holes 27 and 32 because the film is formed twice.

  Further, the insulating film 12 covering the bottoms of the connection hole 27 and the connection hole 32 is removed by etching. Therefore, the second semiconductor substrate 11B is exposed at the bottom of the connection hole 27, and the first semiconductor substrate 11A is exposed at the bottom of the connection hole 32.

  Referring to FIG. 7C, a metal film 29 is formed so as to cover the inside of the through hole 23 and the connection holes 27 and 32 and the upper surface and the back surface of the multilayer substrate 11. Through this step, the connection electrode 17 is formed inside the connection hole 27, and the connection electrode 16 is formed inside the connection hole 32. A through electrode 13 is formed inside the through hole 23. The metal film 29 is composed of a barrier film and a plating film as in the second embodiment.

  Again, as described above, when the barrier film is formed on the wafer table in the chamber, the barrier film formed in the through hole 23 is thicker than the barrier film formed in the connection holes 27 and 32. It is formed.

  Referring to FIG. 7D, the metal film 29 formed on the upper surface and the lower surface of the multilayer substrate 11 is etched to form the first conductive pattern 14 on the upper surface of the multilayer substrate 11, and the second conductive material on the lower surface. A pattern 15 is formed.

  Through the above steps, the circuit board 10 having the structure shown in FIG. 1B is formed. Here, the first conductive pattern 14 formed on the upper surface of the multilayer substrate 11 is connected to the lower second semiconductor substrate 11 </ b> B via the connection electrode 17. The second conductive pattern 15 formed on the lower surface of the multilayer substrate 11 is electrically connected to the upper first semiconductor substrate 11 </ b> A via the connection electrode 16.

<Fourth embodiment>
In this embodiment, a method for manufacturing the circuit board 10 having the structure shown in FIG. 3 will be described with reference to FIG. In this embodiment, the connection hole 27, the connection hole 32, and the through hole 23 having different depths are formed by one etching.

  Referring to FIG. 8A, first, dry etching is performed through an etching mask 34 that covers the upper surface of the multilayer substrate 11 to form connection holes 27, connection holes 32, and through holes 23. In this step, openings 42, 51, 41 having different opening diameters are formed in the etching mask 34. Then, by performing dry etching until the through hole 23 penetrating the laminated substrate 11 in the thickness direction is formed, the connection holes 27 and 32 are simultaneously formed.

  Since the deepest through hole 23 penetrating the laminated substrate 11 is formed from the opening 41, the diameter W1 is the largest and is, for example, about 40 μm.

  The opening diameter W2 of the opening 42 is formed smaller than the diameter W1 of the opening 41 and the diameter W3 of the opening 51. Furthermore, the opening diameter W2 is preferably less than or equal to half of the opening diameter W1 of the opening 41. By doing in this way, the etching speed which advances from the opening part 42 can be made into the half or less of the opening part 41. FIG. Accordingly, the connection hole 27 formed from the opening 42 does not reach the insulating layer 11C, and its tip is located in the middle of the first semiconductor substrate 11A. Specifically, when the opening diameter W1 of the opening 41 is 40 μm, the opening diameter W2 of the opening 42 is preferably 20 μm or less.

  The opening diameter W3 of the opening 51 is formed smaller than the diameter W1 of the opening 41 and larger than the opening diameter W2 of the opening 42. Furthermore, the opening diameter W3 is preferably more than half of the opening diameter W1 of the opening 41. By doing in this way, the etching speed which advances from the opening part 51 is adjusted to more than half of the opening part 41. FIG. Therefore, the connection hole 32 formed from the opening 51 passes through the first semiconductor substrate 11A and the insulating layer 11C and reaches partway in the thickness direction of the second semiconductor substrate 11B.

  Referring to FIG. 8B, next, the laminated substrate 11 is attached to the support substrate 44 via the adhesive 43 with the first semiconductor substrate 11A as the lower surface. Further, the upper surface of the second semiconductor substrate 11B is covered with an etching mask 40 provided with openings 53 and 54, and dry etching is performed to form connection holes 55 and 56.

  In the etching mask 40, two openings 53 and 54 having different opening diameters are formed. Comparing the opening 53 and the opening 54, the opening 54 has a larger opening diameter. For example, the opening diameter W4 of the opening 54 is about 20 μm to 40 μm, and the opening diameter W3 of the opening 53 is about 10 μm to 20 μm. Therefore, when dry etching is performed through the etching mask 40, the etching speed proceeding from the opening 54 is faster than that of the opening 53, so that the connection hole 56 formed by the opening 54 is formed from the opening 53. It is formed deeper than the connection hole 55.

  Here, the connection hole 56 penetrates through the second semiconductor substrate 11B and the insulating layer 11C and extends to the first semiconductor substrate 11A. Further, the connection hole 55 extends partway through the second semiconductor substrate 11B.

  In the above description, the dry etching is individually performed from the upper surface and the lower surface of the multilayer substrate 11.

  Referring to FIG. 8C, next, an insulating film 12 made of a silicon oxide film or a silicon nitride film is formed on the surface of the multilayer substrate 11. The insulating film 12 is also formed on the inner walls of the connection holes 32, 27, 55, 56 and the through hole 23. Further, the insulating film 12 located on the bottom surfaces of the connection holes 32, 27, 55, and 56 is removed.

  Referring to FIG. 8D, after the surface of the multilayer substrate 11 is covered with a metal film, etching is performed to form a first conductive pattern 14 on the surface of the multilayer substrate 11, and a first conductive pattern 14 is formed on the back surface of the multilayer substrate 11. Two conductive patterns 15 are formed. Further, a metal film is also formed in the connection holes 32 and 27 provided from the upper surface of the multilayer substrate 11, and the connection electrodes 17 and 52 are formed. Furthermore, a metal film is formed also in the connection holes 55 and 56 provided from the lower surface of the multilayer substrate 11, and the connection electrodes 51 and 16 are formed. Further, a metal film is also formed on the inner wall of the through hole 23 to form the through electrode 13.

  Through the above steps, the circuit board 10 shown in FIG. 3 is formed.

It is a figure which shows the circuit board of this invention, (A)-(C) is sectional drawing. It is a figure which shows the circuit board of this invention, (A)-(C) is sectional drawing. It is sectional drawing which shows the circuit board of this invention. It is a figure which shows the structure of the circuit apparatus by which the circuit board of this invention was employ | adopted, (A) and (B) are sectional drawings. It is a figure which shows the manufacturing method of the circuit board of this invention, (A)-(C) is sectional drawing. It is a figure which shows the manufacturing method of the circuit board of this invention, (A)-(D) is sectional drawing. It is a figure which shows the manufacturing method of the circuit board of this invention, (A)-(D) is sectional drawing. It is a figure which shows the manufacturing method of the circuit board of this invention, (A)-(D) is sectional drawing. It is sectional drawing which shows the conventional circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit board 11 Laminated board 12 Insulating film 13 Through electrode 14 1st conductive pattern 15 2nd conductive pattern 16 Connection electrode 17 Connection electrode 18 Circuit element 18A Chip element 18B Semiconductor element 19 Bump electrode 20A, 20B Circuit apparatus 21 External electrode 22 Covering Layer 23 Through-hole 24 Recess 25 Metal fine wire 26 Bonding material 27 Connection hole 29 Metal film 30 Mounting substrate 31 Conductive path 32 Connection hole 34 Etching mask 35 Barrier film 36 Underfill 37 Sealing resin 40 Etching mask 41, 42 Opening 43 Adhesion Agent 44 Support substrate 51 Connection electrode 52 Connection electrode 53, 54, 57 Opening 55, 56 Connection hole

Claims (17)

A first impurity semiconductor substrate connected to either the ground potential or the power supply potential via the first connection electrode, and a second connected to the other of the ground potential or the power supply potential via the second connection electrode. A laminated substrate in which an impurity semiconductor substrate is laminated via an insulating layer;
A through hole penetrating the laminated substrate;
An insulating film covering the side wall of the through hole and the upper and lower surfaces of the multilayer substrate;
A through electrode penetrating the laminated substrate via the insulating film formed on the side wall of the through hole,
A first conductive pattern formed on an upper surface of the first impurity semiconductor substrate via the insulating film;
A second conductive pattern formed on the back surface of the second impurity semiconductor substrate through the insulating film;
A circuit board comprising: The first connection electrode, through the first of said insulating film formed on the side wall and upper surface of the first impurity semiconductor substrate of a first connection hole formed from the surface of the impurity semiconductor substrate to a predetermined depth position Formed in the first connection hole and electrically connected to the first impurity semiconductor substrate,
Said second connecting electrode via the second of said insulating film formed on the side wall and the upper surface of the second impurity semiconductor substrate of the second connection hole formed from the surface of the impurity semiconductor substrate to a predetermined depth position The circuit board according to claim 1, wherein the circuit board is formed in the second connection hole and electrically connected to the second impurity semiconductor substrate. A first impurity semiconductor substrate connected to either the ground potential or the power supply potential via the first connection electrode, and a second connected to the other of the ground potential or the power supply potential via the second connection electrode. A laminated substrate in which an impurity semiconductor substrate is laminated via an insulating layer;
A through hole penetrating the laminated substrate;
An insulating film covering the side wall of the through hole and the upper and lower surfaces of the multilayer substrate;
A through electrode penetrating the laminated substrate through the insulating film formed on the side wall of the through hole;
A first conductive pattern formed on an upper surface of the first impurity semiconductor substrate via the insulating film;
A second conductive pattern formed on the back surface of the second impurity semiconductor substrate through the insulating film,
The first connection electrode, the second said impurity semiconductor substrate through the first impurity semiconductor substrate the insulating film formed between the side wall of the extended connecting hole on the upper surface of the first impurity semiconductor substrate to Is formed in the connection hole through and is electrically connected to the first impurity semiconductor substrate,
The second connection electrode, the insulating film formed on the side wall and upper surface of the first impurity semiconductor substrate of a first impurity semiconductor substrate through extending to the second impurity semiconductor substrate connecting hole A circuit board, which is formed in the connection hole through the substrate and electrically connected to the second impurity semiconductor substrate. The first connection electrode, through the first of said insulating film formed on the side wall and upper surface of the first impurity semiconductor substrate of a first connection hole formed from the surface of the impurity semiconductor substrate to a predetermined depth position Formed in the first connection hole and electrically connected to the first impurity semiconductor substrate,
The second connection electrode passes through the first impurity semiconductor substrate and extends to the second impurity semiconductor substrate through the insulating film formed on a side wall of the second connection hole. The circuit board according to claim 1, wherein the circuit board is formed inside and electrically connected to the second impurity semiconductor substrate. A laminated substrate comprising a first impurity semiconductor substrate and a second impurity semiconductor substrate laminated via an insulating layer;
A through electrode provided through an insulating film in a through hole penetrating the laminated substrate in the thickness direction;
A first connection electrode electrically connected to the first impurity semiconductor substrate;
A second connection electrode electrically connected to the second impurity semiconductor substrate;
A conductive pattern formed on the surface of the insulating film covering the laminated substrate,
The first impurity semiconductor substrate is connected to a power supply potential; the second impurity semiconductor substrate is connected to a ground potential;
The conductive pattern includes a ground pattern connected to a ground potential and a power supply pattern connected to a power supply potential,
The power supply pattern is connected to the first impurity semiconductor substrate through the first connection electrode,
The circuit board, wherein the ground pattern is connected to the second impurity semiconductor substrate through the second connection electrode. The circuit board according to claim 5 , wherein the second connection electrode extends through the first impurity semiconductor substrate to the second impurity semiconductor substrate. The first connection electrode, a circuit board according to claim 5 or claim 6, characterized in that extending to the middle of the thickness direction of the first impurity semiconductor substrate. A third connection electrode connected to the first impurity semiconductor substrate; and a fourth connection electrode connected to the second impurity semiconductor substrate;
The first impurity semiconductor substrate is connected to an external power supply potential via the third connection electrode, and the second impurity semiconductor substrate is connected to an external ground potential via the fourth connection electrode. The circuit board according to claim 5 , characterized in that: Preparing a laminated substrate in which a first impurity semiconductor substrate and a second impurity semiconductor substrate are laminated via an insulating layer;
Covering one main surface of the multilayer substrate with an etching mask, and forming a first opening and a second opening having different opening diameters in the etching mask;
Etching the laminated substrate through the etching mask to form a first connection hole exposing the first semiconductor substrate at the bottom and a second connection hole exposing the second semiconductor substrate from the first opening. And forming a through hole penetrating the laminated substrate from the second opening,
The first connection holes, the second connection holes, and the through holes are formed through insulating films formed on sidewalls of the first connection holes, the second connection holes, and the through holes on the top surface and the back surface of the multilayer substrate. Inside, a conductive material is formed on the top surface and the back surface of the multilayer substrate, a first connection electrode connected to the first impurity semiconductor substrate, a second connection electrode and a through electrode connected to the second impurity semiconductor substrate And forming a first conductive pattern and a second conductive pattern on the top and back surfaces of the multilayer substrate, and
The first impurity semiconductor substrate is connected to either a ground potential or a power supply potential via the first connection electrode, and the second impurity semiconductor substrate is connected to a ground potential or a power supply potential via the second connection electrode. A method of manufacturing a circuit board, wherein the circuit board is connected to any one of the above .   The method for manufacturing a circuit board according to claim 9, wherein the first opening is formed smaller than the second opening. The first connection hole is extended partway in the thickness direction of the first impurity semiconductor substrate to electrically connect the first connection electrode to the first impurity semiconductor substrate. A method for manufacturing a circuit board according to claim 9 or 10 . The second connection hole extends through the first impurity semiconductor substrate and the insulating layer to the second impurity semiconductor substrate, and the second connection electrode, the second impurity semiconductor substrate, method of manufacturing a circuit board according to claim 9 or claim 10, characterized in that electrically connecting. Preparing a laminated substrate in which a first impurity semiconductor substrate and a second impurity semiconductor substrate are laminated via an insulating layer;
Covering one principal surface of the multilayer substrate with an etching mask, and forming a first opening, a second opening, and a third opening having different opening diameters in the etching mask;
The laminated substrate is etched through the etching mask to form a first connection hole from the first opening through which the first impurity semiconductor substrate is exposed at the bottom, and the second impurity semiconductor substrate from the bottom. Forming a second connection hole from the second opening, and forming a through-hole penetrating the laminated substrate from the third opening;
Inside of the first connection hole, the second connection hole and the through hole through insulating films formed on the upper surface and the back surface of the multilayer substrate from the side walls of the first connection hole, the second connection hole and the through hole. A conductive material is formed on the top surface and the back surface of the multilayer substrate, a first connection electrode electrically connected to the first impurity semiconductor substrate, and a second electrode electrically connected to the second impurity semiconductor substrate. Forming a connection electrode and a through electrode, and forming a first conductive pattern and a second conductive pattern on the top surface and the back surface of the multilayer substrate,
The first impurity semiconductor substrate is connected to either a ground potential or a power supply potential via the first connection electrode, and the second impurity semiconductor substrate is connected to a ground potential or a power supply potential via the second connection electrode. A method of manufacturing a circuit board, wherein the circuit board is connected to any one of the above . The method for manufacturing a circuit board according to claim 13 , wherein the second opening is formed larger than the first opening and smaller than the third opening. The first connection hole is extended partway in the thickness direction of the first impurity semiconductor substrate to electrically connect the first connection electrode to the first impurity semiconductor substrate. A method for manufacturing a circuit board according to claim 13 or claim 14. The second connection hole extends through the first impurity semiconductor substrate and the insulating layer to the second impurity semiconductor substrate, and the second connection electrode is electrically connected to the second impurity semiconductor substrate. method of manufacturing a circuit board according to any one of claims 13 to claim 15, characterized in that connected. And a circuit board according to any one of claims 1 to 8, a semiconductor device characterized by comprising a semiconductor element fixed to the main surface of the circuit board.

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