JP2010054210A - Method of manufacturing capacitance type semiconductor physical quantity sensor and capacitance-type semiconductor physical quantity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent troubles such as deposition without increasing manufacturing cost. <P>SOLUTION: After making the potential of a movable electrode 4 and the potential of a fixed electrode 5 the same by electrically connecting a through-hole conductor 6 and a through-hole conductor 7 with a potential equalization conductor 8, and performing anodic bonding, the movable electrode 4 and the fixed electrode 5 are cut off by cutting the equalization conductor 8 when pressure sensors are obtained by cutting a semiconductor wafer 1. As a result, an electrostatic attractive force is generated between the movable electrode 4 and the fixed electrode 5 by a voltage applied when the anodic bonding is performed, so that the troubles such as deposition are prevented. Moreover, the equalization conductor 8 is cut when the pressure sensors are obtained by cutting the semiconductor wafer 1, thereby the equalization conductor 8 can be cut without using any special device or process and without increasing the manufacturing cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a capacitive semiconductor physical quantity sensor that detects a physical quantity such as pressure or acceleration by detecting a capacitance between a fixed electrode and a movable electrode.

Conventionally, a semiconductor substrate having a movable electrode that is displaced when a physical quantity such as pressure or acceleration is applied, and an insulating substrate provided with a fixed electrode at a position facing the movable electrode, the fixed electrode accompanying the displacement of the movable electrode. A capacitance type semiconductor physical quantity sensor that detects a physical quantity applied to a movable electrode by detecting a change in capacitance between the movable electrode and the movable electrode is known.
JP 2006-200920 A JP-A-9-196700

  According to the conventional method of manufacturing a capacitance type semiconductor physical quantity sensor, when anodic bonding of a semiconductor substrate and an insulating substrate, an electrostatic attraction force is generated between a movable electrode and a fixed electrode by an applied voltage, so that welding is performed. Such a problem may occur. In order to solve such a problem, Patent Documents 1 and 2 disclose that the movable electrode and the fixed electrode have the same potential by electrically connecting the movable electrode and the fixed electrode so as not to generate an electrostatic attraction force. Thus, after the anodic bonding, a manufacturing method is described in which the electrically connected movable electrode and the fixed electrode are separated. However, in the manufacturing methods described in Patent Documents 1 and 2, a capacitive semiconductor physical quantity sensor is manufactured at low cost in order to separate the movable electrode and the fixed electrode by using a special device or process such as laser irradiation or heating by current. It becomes difficult to do.

  The present invention has been made to solve the above problems, and provides a method for manufacturing a capacitance type semiconductor physical quantity sensor capable of preventing occurrence of defects such as welding without increasing the manufacturing cost. It is in.

  The manufacturing method of a capacitance type semiconductor physical quantity sensor according to the present invention is formed by bringing a peripheral region of an insulating substrate and a semiconductor substrate into contact with each other and then anodically bonding them by applying a voltage between the substrates. In a manufacturing method of a capacitance type semiconductor physical quantity sensor, in which a fixed electrode is provided on the bonding surface side of the substrate and a movable electrode is provided on the bonding surface side of the semiconductor substrate, at least formed in the in-plane direction of the semiconductor wafer. A first step of electrically connecting the movable electrode and the fixed electrode between the two capacitance type semiconductor physical quantity sensors in the region inside the insulating substrate or the back surface side by the same potential wiring; and between the insulating substrate and the semiconductor substrate A second step of forming a capacitance type semiconductor physical quantity sensor in an in-plane direction of the semiconductor wafer by anodically bonding the insulating substrate and the semiconductor substrate by applying a voltage to the semiconductor wafer; and a semiconductor wafer And a third step of cutting the equipotential lines when cutting the Riseiden capacitive semiconductor physical quantity sensor.

  The insulating substrate has a reference electrode for sensitivity adjustment formed in a region other than the bonding surface. In the first step, the movable electrode, the fixed electrode, and the reference electrode between at least two capacitive semiconductor physical quantity sensors Are preferably electrically connected by the same potential wiring. The insulating substrate has a dummy electrode formed in a region other than the bonding surface. In the first step, the movable electrode, the fixed electrode, and the dummy electrode are electrically connected between at least two capacitance type semiconductor physical quantity sensors. It is desirable to connect. In addition, a concave portion may be formed in a surface region of the movable electrode facing the insulating substrate that does not face the fixed electrode, the reference electrode, and the dummy electrode.

  As the insulating substrate, an LTCC substrate or an electrode-embedded glass substrate may be used. In the first step, it is desirable that the movable electrodes and the fixed electrodes of all the capacitive semiconductor physical quantity sensors existing in the in-plane direction of the semiconductor chip are electrically connected by the same potential wiring. In the third step, capacitance semiconductor physical quantity is obtained by dicing, drilling with a drill, or forming a notch on the surface of the insulating substrate or semiconductor substrate, and dividing the semiconductor wafer along the notch. It is preferable to cut out the sensor and the same potential wiring.

  According to the method for manufacturing a capacitive semiconductor physical quantity sensor of the present invention, it is possible to prevent the occurrence of defects such as welding without increasing the manufacturing cost.

  Hereinafter, with reference to FIG. 1 and FIG. 2, the manufacturing method of the pressure sensor which becomes embodiment of this invention is demonstrated. 1 is a cross-sectional view of a pressure sensor according to an embodiment of the present invention, and FIG. 2 is a top view of the pressure sensor according to an embodiment of the present invention. In FIG. 1, two pressure sensors C1 and C2 adjacent in the in-plane direction of the semiconductor wafer are shown. In FIG. 2, the glass substrate on the upper surface side of the pressure sensor is a transparent member. It is shown in perspective.

  In the pressure sensor manufacturing method according to the embodiment of the present invention, first, the thick film portion 3 and the movable electrode (pressure-sensitive portion) 4 are formed by etching the front surface side and the back surface side of the semiconductor wafer 1 such as a silicon wafer. Form. Next, the fixed electrode 5 is formed by vapor deposition or sputtering at a position facing the movable electrode 4 on the surface of the low-temperature co-fired ceramics (LTC) substrate 2 and electrically connected to the fixed electrode 5. A through-hole wiring 6 and a through-hole wiring 7 electrically connected to the movable electrode 4 are formed on the LTCC substrate 2. Next, equipotential wirings 8 and 9 for electrically connecting the through-hole wiring 6 and the through-hole wiring 7 between the two pressure sensors in the dividing margin region R1 between the two pressure sensor regions C1 and C2 are disposed on the LTCC substrate. 2 to form. The equipotential wirings 8 and 9 are arranged in order to ensure the airtightness of the airtight space formed between the movable electrode 4 and the fixed electrode 5 when the semiconductor wafer 1 and the LTCC substrate 2 are anodically bonded. The substrate 2 is formed in a region other than the bonding surface with the semiconductor wafer 1.

  Next, the surface of the semiconductor wafer 1 and the surface of the LTCC substrate 2 are brought into contact with each other so that the movable electrode 4 and the fixed electrode 5 face each other. Next, the anode of the anodic bonding power source is connected to the semiconductor wafer 1 and the negative electrode of the anodic bonding power source is connected to the LTCC substrate 2, and a voltage is applied between the semiconductor wafer 1 and the LTCC substrate 2. A current is passed between the wafer 1 and the LTCC substrate 2 to integrate the contact portion between them, in this embodiment, the thick film portion 3 region by anodic bonding. Finally, the pressure sensor is cut out from the semiconductor wafer 1 by cutting the joined body including the equipotential wiring 8 in the dividing margin region R1. The pressure sensor manufactured in this way outputs the pressure applied to the movable electrode 4 as a change in capacitance between the movable electrode 4 and the fixed electrode 5 due to a change in the gap length between the movable electrode 4 and the fixed electrode 5. can do.

  As is clear from the above description, in the pressure sensor manufacturing method according to the embodiment of the present invention, the through-hole wiring 6 and the through-hole wiring 7 are electrically connected by the same potential wiring 8 to the movable electrode 4. After performing anodic bonding with the fixed electrode 5 set to the same potential, the movable electrode 4 and the fixed electrode 5 are separated by cutting the same potential wiring 8 when cutting out the pressure sensor from the semiconductor wafer 1. In addition, since an electrostatic attraction force is generated between the movable electrode 4 and the fixed electrode 5 by the applied voltage, it is possible to prevent problems such as welding. Further, according to the pressure sensor manufacturing method according to the embodiment of the present invention, the equipotential wiring 8 is cut when the pressure sensor is cut out from the semiconductor wafer 1, so that the manufacturing cost can be reduced without using a special device or process. The equipotential wiring 8 can be cut without increasing it.

  In this embodiment, the fixed electrode 5 is formed on the LTCC substrate 2, but the present invention is not limited to this embodiment. For example, the fixed electrode 5 is formed on an electrode-embedded glass substrate as shown in FIG. You may make it do. However, in this case, the fixed electrode 5 is formed of a conductor such as metal or silicon. Further, as shown in FIG. 4, a reference electrode 10 for sensitivity adjustment is formed on the surface of the LTCC substrate 2, and a through hole wiring 11 electrically connected to the reference electrode 10 by the same potential wiring 8 is connected to the through hole of the adjacent pressure sensor. The reference electrode 10, the movable electrode 4, and the fixed electrode 5 may be set to the same potential by being electrically connected to the wiring 6 and the through-hole wiring 7.

  Further, as shown in FIG. 5, a dummy electrode 12 is formed on the surface of the LTCC substrate 2, and the through-hole wiring 13 electrically connected to the dummy electrode 12 by the same potential wiring 8 is connected to the through-hole wiring 6 and the through-hole of the adjacent pressure sensor. The dummy electrode 12, the movable electrode 4, and the fixed electrode 5 may be set to the same potential by being electrically connected to the hole wiring 7. According to such a configuration, the surface area of the LTCC substrate 2 other than the bonding area with the semiconductor wafer 1 is covered by the dummy electrode 12 as wide as possible, so that the surface other than the bonding area with the semiconductor wafer 1 is covered. The region can be kept at the same potential, and it is possible to more reliably prevent the occurrence of defects such as welding.

  Further, as shown in FIG. 6, in the surface area of the movable electrode 4 facing the LTCC substrate 2, the recess 14 may be formed in the surface area not facing the fixed electrode 5, the reference electrode, and the dummy electrode 12. . According to such a configuration, the movable electrode 4 and the fixed electrode 5 are fixed to the movable electrode 4 even in a region where the equipotential wiring 8 cannot be formed due to the sensor structure, such as a region where the insulation between the movable electrode 4 and the fixed electrode 5 must be ensured. By increasing the gap length between the electrodes 5, it is possible to prevent problems such as welding. Further, as shown in FIG. 7, it is desirable to electrically connect the movable electrodes 4 and the fixed electrodes 5 of all the pressure sensors existing in the in-plane direction of the semiconductor wafer 1 by the same potential wiring 8. According to such a manufacturing method, it is possible to prevent the movable electrode 4 from sticking to the fixed electrode 5 with respect to all the pressure sensor chips.

  In the present embodiment, the present invention is applied to a manufacturing method of a pressure sensor. However, the present invention is not limited to the present embodiment, and a semiconductor wafer is formed by insulating substrates 2a and 2b as shown in FIG. 1 can be applied to a method of manufacturing an acceleration sensor that detects acceleration applied to the movable electrode (weight portion) 15 formed on the semiconductor wafer 1. In the acceleration sensor shown in FIG. 8, a concave portion 16 is formed on the surface of the glass substrate 2b in order to prevent the movable electrode 15 from coming into contact with the lower glass substrate 2b. The pressure sensor is cut out and the equipotential wiring 8 is cut by (1) cutting the dividing margin region R1 by dicing as shown in FIG. 9 (a), and (2) drilling as shown in FIG. 9 (b). Or a hole is formed in the dividing margin region R1, or (3) the notches 17a and 17b are formed on the surface of the LTCC substrate 2 or the semiconductor wafer 1 as shown in FIGS. By dividing the joined body along the notches 17a and 17b, it is possible to carry out without using a special device.

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by description and drawing which make a part of indication of this invention by this embodiment. That is, all other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

It is sectional drawing which shows the structure of the pressure sensor used as embodiment of this invention. It is a top view which shows the structure of the pressure sensor shown in FIG. It is sectional drawing which shows the structure of the modification of the pressure sensor shown in FIG. It is a top view which shows the structure of the modification of the pressure sensor shown in FIG. It is a top view which shows the structure of the modification of the pressure sensor shown in FIG. It is a top view which shows the structure of the modification of the pressure sensor shown in FIG. It is a figure for demonstrating the application example of the manufacturing method of the pressure sensor used as embodiment of this invention. It is sectional drawing which shows the structure of the acceleration sensor used as embodiment of this invention. It is a figure for demonstrating the manufacturing method of the pressure sensor used as embodiment of this invention. It is a figure for demonstrating the manufacturing method of the pressure sensor used as embodiment of this invention.

Explanation of symbols

1: Semiconductor wafer 2: Low-temperature co-fired ceramics (LTC) substrate 3: Thick film part 4: Movable electrode 5: Fixed electrode 6, 7: Through-hole wiring 8, 9: Equipotential wiring C1 , C2: Pressure sensor region R1: Dividing margin region

Claims (13)

The insulating substrate and the semiconductor substrate are formed by contacting the peripheral regions facing each other and then anodic bonding by applying a voltage between the substrates, and a fixed electrode is provided on the bonding surface side of the insulating substrate, and the semiconductor In the manufacturing method of the capacitance type semiconductor physical quantity sensor in which the movable electrode is provided on the bonding surface side of the substrate,
A movable electrode and a fixed electrode between at least two capacitance-type semiconductor physical quantity sensors formed in the in-plane direction of the semiconductor wafer are electrically connected to each other in the region on the inside or back side of the insulating substrate by the same potential wiring. And forming a capacitive semiconductor physical quantity sensor in an in-plane direction of the semiconductor wafer by anodically bonding the insulating substrate and the semiconductor substrate by applying a voltage between the insulating substrate and the semiconductor substrate. A method of manufacturing a capacitive semiconductor physical quantity sensor, comprising: two processes; and a third process of cutting the equipotential wiring when the capacitive semiconductor physical quantity sensor is cut out from the semiconductor wafer. In the manufacturing method of the capacitance type semiconductor physical quantity sensor according to claim 1,
The insulating substrate includes a reference electrode for sensitivity adjustment formed in a region other than the bonding surface, and in the first step, a movable electrode, a fixed electrode, and a reference electrode between at least two capacitive semiconductor physical quantity sensors. Are electrically connected by the same potential wiring. A method of manufacturing a capacitance type semiconductor physical quantity sensor. In the manufacturing method of the capacitance type semiconductor physical quantity sensor according to claim 1 or 2,
The insulating substrate has a dummy electrode formed in a region other than the bonding surface. In the first step, the movable electrode, the fixed electrode, and the dummy electrode are electrically connected between at least two capacitive semiconductor physical quantity sensors. A method of manufacturing a capacitance type semiconductor physical quantity sensor, characterized by comprising: In the manufacturing method of the capacitive semiconductor physical quantity sensor according to any one of claims 1 to 3,
And forming a recess in a surface region of the movable electrode facing the insulating substrate, the surface region not facing the fixed electrode, the reference electrode, and the dummy electrode. Manufacturing method of physical quantity sensor. In the manufacturing method of the capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 4,
A manufacturing method of a capacitance type semiconductor physical quantity sensor, wherein an LTCC substrate is used as the insulating substrate. In the manufacturing method of the capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 4,
A method of manufacturing a capacitance type semiconductor physical quantity sensor, wherein an electrode-embedded glass substrate is used as the insulating substrate. In the manufacturing method of the capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 6,
In the first step, the movable electrode and the fixed electrode of all the capacitive semiconductor physical quantity sensors existing in the in-plane direction of the semiconductor chip are electrically connected by the same potential wiring. Manufacturing method of semiconductor physical quantity sensor. The method of manufacturing a capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 7,
The method of manufacturing a capacitance type semiconductor physical quantity sensor, wherein the capacitance type semiconductor physical quantity sensor is a pressure sensor that detects a pressure applied to the movable electrode. The method of manufacturing a capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 7,
The method of manufacturing a capacitance type semiconductor physical quantity sensor, wherein the capacitance type semiconductor physical quantity sensor is an acceleration sensor that detects an acceleration applied to the movable electrode. The method of manufacturing a capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 9,
In the third step, the capacitive semiconductor physical quantity sensor is cut out by dicing and the equipotential wiring is cut. The method of manufacturing a capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 9,
In the third step, the capacitive semiconductor physical quantity sensor is cut out and the equipotential wiring is cut out by drilling with a drill. The method of manufacturing a capacitance type semiconductor physical quantity sensor according to any one of claims 1 to 9,
In the third step, a notch is formed on the surface of the insulating substrate or the semiconductor substrate, and the semiconductor wafer is cut along the notch to cut out the capacitive semiconductor physical quantity sensor and cut the equipotential wiring. A method for manufacturing a capacitance type semiconductor physical quantity sensor, characterized in that:   A capacitance-type semiconductor physical quantity sensor manufactured by the method for manufacturing a capacitance-type semiconductor physical quantity sensor according to any one of claims 1 to 12.

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