JP2011155075A - Offset voltage-adjusting structure of bridge circuit, and electronic component equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an offset voltage-adjusting structure of a bridge circuit which is low-cost without requiring a time for adjustment, and to provide an electronic component equipped therewith. <P>SOLUTION: The offset voltage-adjusting structure of the bridge circuit includes bridge resistances R1, R2, R3, R4 formed on a substrate 100, a resistance region 200 formed on the substrate 10, a plurality of three contacts 300 or more formed in the resistance region 200, and a wiring portion 400 electrically connecting the contacts 300 to the bridge resistances R1, R2, R3, R4, wherein the bridge circuit 10 comprises the bridge resistances R1, R2, R3, R4, and adjusting resistances Ra and Rb selected out of the plurality of contacts 300 by the wiring portion 400 and connected to the bridge resistances R1, R2, R3, R4, the selection being made in a process of manufacturing the wiring portion 400. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a bridge circuit offset voltage adjusting structure and an electronic component including the same.

  Conventionally, as a method for adjusting the offset voltage of the bridge circuit, there is a method of adjusting a resistance value by trimming a part of an adjustment pattern structure in a ladder resistance region formed on a semiconductor substrate. That is, as a thin film resistor adjustment pattern structure, there is an adjustment structure having a ladder structure in a thin film resistor (for example, Patent Document 1). In the thin film resistor in this adjustment structure, a ladder resistor adjustment pattern structure for adjusting the resistance value is provided between the input portion and the output portion of the resistor. It is said that the thin film resistor can be adjusted to the optimum resistance value by sequentially cutting the ladder portion with a laser beam while measuring the resistance value.

Japanese Utility Model Publication No. 72-106

  According to the adjustment structure having the ladder structure of the thin film resistor disclosed in Patent Document 1, it is possible to adjust the optimum resistance value by sequentially cutting the ladder portion with a laser beam. It took time, and the cost increase by this was a problem.

  Accordingly, it is an object of the present invention to provide a low-cost bridge circuit offset voltage adjustment structure and an electronic component including the same without requiring time for adjustment.

  [1] In order to achieve the above object, the present invention provides a bridge resistor formed on a substrate, a resistor region formed on the substrate, a plurality of three or more contacts formed in the resistor region, A bridge portion electrically connecting the contact and the bridge resistor, and a bridge circuit is formed from the bridge resistor and an adjustment resistor selected from the plurality of contacts by the wire portion and connected to the bridge resistor. Provided is an offset voltage adjustment structure for a bridge circuit characterized by being configured.

  [2] The bridge circuit offset voltage adjustment structure according to [1], wherein the selection is performed in a manufacturing process of the wiring portion.

  [3] In order to achieve the above object, the present invention provides a substrate, a bridge resistor formed on the substrate, a resistance region formed on the substrate, and a plurality of three or more formed in the resistance region. A contact portion, and a wiring portion that electrically connects the contact and the bridge resistor, and the bridge resistor and an adjustment resistor selected from the plurality of contacts by the wiring portion and connected to the bridge resistor An electronic component comprising a bridge circuit is provided.

  [4] The electronic component according to [3], wherein the selection is performed in a manufacturing process of the wiring portion.

  According to the present invention, it is possible to provide a low-cost bridge circuit offset voltage adjusting structure and an electronic component including the same without requiring time for adjustment.

FIG. 1 is a circuit diagram showing a configuration of a bridge circuit 10 according to an embodiment of the present invention. 2A and 2B are an upper plan view (a) and a cross-sectional view (b) of the semiconductor element corresponding to the portion AA of the adjustment resistor Rb and the bridge resistor R4 in the circuit diagram of FIG. is there. 3A to 3F are process diagrams for explaining the semiconductor manufacturing process of the adjustment resistor portion of the bridge circuit 10 according to the embodiment of the present invention in the order of processes. 4A and 4B show an example of an aluminum wiring pattern, where FIG. 4A is an equivalent circuit diagram, FIG. 4B is an upper plan view of a corresponding semiconductor element, and FIG. 4C is a cross section of the semiconductor element. FIG. FIG. 5 shows an example of an aluminum wiring pattern. In each figure, (a) is an equivalent circuit diagram, and (b) is an upper plan view of a semiconductor element corresponding thereto. FIG. 6 shows an example of an aluminum wiring pattern. In each figure, (a) is an equivalent circuit diagram, and (b) is a top plan view of a corresponding semiconductor element. FIG. 7A shows a configuration in which resistors R11, R12, R13, and R14 are bridge-connected in the horizontal and vertical directions, and (b) bridges resistors R15, R16, R17, and R18 in an orthogonal 45 degree direction. It is a circuit connection diagram which shows the connected structure. FIG. 8 is a plan view showing an MR sensor 800 as an electronic component formed by laying out the circuit connection diagram described above on the substrate 100 in a predetermined pattern and formed by a semiconductor manufacturing process. .

(Embodiment of the present invention)
The offset voltage adjustment structure of the bridge circuit 10 according to the embodiment of the present invention includes a bridge resistor R1, R2, R3, R4 formed on the substrate 100, a resistor region 200 formed on the substrate 100, and a resistor region. 200 having three or more contacts 300 formed in 200, and a wiring part 400 that electrically connects the contact 300 and the bridge resistors R1, R2, R3, and R4, and the bridge resistors R1, R2, R3, and R4 In addition, the bridge circuit 10 is configured by the adjustment resistors Ra and Rb selected from the plurality of contacts 300 by the wiring unit 400 and connected to the bridge resistors R1, R2, R3, and R4. This selection is performed in the manufacturing process of the wiring part 400. FIG. 1 is a circuit diagram showing the above configuration.

  The electronic component having the bridge circuit 10 according to the embodiment of the present invention includes a substrate 100, bridge resistors R1, R2, R3, and R4 formed on the substrate 100, and a resistance region formed on the substrate 100. 200, three or more contacts 300 formed in the resistance region 200, and a wiring portion 400 that electrically connects the contact 300 and the bridge resistors R1, R2, R3, and R4, and the bridge resistor R1, The bridge circuit 10 includes R2, R3, and R4 and adjustment resistors Ra and Rb selected from the plurality of contacts 300 by the wiring unit 400 and connected to the bridge resistors R1, R2, R3, and R4. This selection is performed in the manufacturing process of the wiring part 400.

  As shown in FIG. 1, the bridge circuit 10 includes bridge resistors R1, R2, R3, and R4 and adjustment resistors Ra and Rb. The bridge resistors R2 and R4 are connected to the bridge resistors R1 and R3 in a state of being connected in series with the adjustment resistors Ra and Rb, respectively. A power supply voltage Vcc is applied to one end of the bridge resistors R1 and R3. The other end of the bridge resistor R1 is connected to the bridge resistor R2, and the connection point is an output V1. The other end of the bridge resistor R3 is connected to the bridge resistor R4, and the connection point is an output V2. The adjustment resistor Ra connected in series with the bridge resistor R2 and the adjustment resistor Rb connected in series with the bridge resistor R4 are both connected to the ground GND.

  The bridge circuit 10 shown in FIG. 1 outputs a difference signal between the output V1 and the output V2. When this bridge circuit is used for a magnetoresistive element such as an MR sensor, for example, the resistance values of the bridge resistors R1, R2, R3, and R4 are changed by a magnetic field, and a change in a difference signal due to the magnetoresistive effect is detected. Therefore, highly accurate offset adjustment is required by adjusting the resistance value. In the embodiment of the present invention, the resistance value for offset adjustment is adjusted by adjusting the resistance values of the adjustment resistors Ra and Rb.

  2A and 2B are an upper plan view (a) and a cross-sectional view (b) of the semiconductor element corresponding to the portion AA of the adjustment resistor Rb and the bridge resistor R4 in the circuit diagram of FIG. is there. The adjustment resistor Rb includes an insulating layer 110 formed on the substrate 100, a resistance region 200 formed on the insulating layer 110, and a plurality of three or more contacts 300 formed in an ohmic connection state on the resistance region 200. , And a wiring section 400 that electrically connects the contact 300 and the bridge resistor R4. Here, the wiring section 400 is an aluminum wiring, and any one or more contacts 300 among the plurality of contacts 300 are connected to the adjustment resistor Rb by the aluminum wiring, and any one or more contacts 300 are connected. The aluminum wiring is connected to the ground GND. The configuration on the adjustment resistor Ra side is the same. This connection pattern is implemented in the wiring process during the semiconductor manufacturing process so that the offset voltage of the bridge circuit 10 shown in FIG.

  3A to 3F are process diagrams for explaining the semiconductor manufacturing process of the adjustment resistor portion of the bridge circuit 10 according to the embodiment of the present invention in the order of processes. Hereinafter, a manufacturing method will be described for the adjustment resistor portion in the order of steps.

  As shown in FIG. 3A, an insulating layer 110 is formed on the entire surface of the substrate 100 by a known CVD method or the like, and a silicon chrome (SiCr) or nickel chrome (NiCr) system is formed on the insulating layer 110. The thin film resistor material is patterned into a predetermined shape to form a resistance region 200 that is a thin film resistor layer having a layer thickness of, for example, about 10 to 20 nm.

  Next, as shown in FIG. 3B, an interlayer insulating film 500 such as SiO 2 is formed so as to cover the entire resistance region 200, and then a resist 600 is applied and patterned to form an interlayer insulating film 500. An opening 610 corresponding to the contact 300 to be formed is formed.

  Next, as shown in FIG. 3C, an opening (contact hole) 510 corresponding to the opening 610 is formed in the interlayer insulating film 500 by dry etching, and then the resist 600 is removed.

  Next, as shown in FIG. 3D, a metal such as tungsten is deposited on the entire surface by a known CVD method to form a metal layer 700. In some cases, prior to the formation of the metal layer 700, a thin layer of titanium or titanium nitride can be formed as an adhesion layer for improving adhesion.

  Next, as shown in FIG. 3E, the metal layer 700 is left only in the opening (contact hole) 510 by a known method such as normal dry etching or CMP. The metal layer 700 is removed, and each surface of the metal layer 700 remaining in the interlayer insulating film 500 and the opening 510 is planarized. Thereby, the contact 300 connected to the resistance region 200 can be formed in the interlayer insulating film 500. In the embodiment of the present invention, three or more contacts 300 are formed.

  Next, as shown in FIG. 3 (f), the wiring part (wiring layer) 400 is connected to the contact 300 and the contact on the bridge resistance R2, R4 side or the contact on the ground GND side by aluminum Al or the like. Form. In the process of forming the wiring portion (wiring layer) 400, the mask pattern used for the aluminum wiring is appropriately changed so that the offset voltage of the bridge circuit 10 shown in FIG.

  This mask pattern is, for example, a bridge circuit 10 formed with various aluminum wiring patterns based on various mask patterns on a semiconductor wafer in a trial production stage, or an electronic component including the bridge circuit 10 as a TEG (Test Element). It is possible to manufacture by selecting and using an optimal mask pattern in the mass production process by measuring the pattern in advance.

  4A and 4B show an example of an aluminum wiring pattern, where FIG. 4A is an equivalent circuit diagram, FIG. 4B is an upper plan view of a corresponding semiconductor element, and FIG. 4C is a cross section of the semiconductor element. FIG. 5 and 6 also show examples of aluminum wiring patterns. In each figure, (a) is an equivalent circuit diagram, and (b) is an upper plan view of a semiconductor element corresponding thereto. It is.

  In the example of the aluminum wiring pattern shown in FIGS. 4A to 4C, the wiring portion 400 is connected to the contact 300, but the current does not flow through the resistance region 200 because it is connected to one contact 300. It is. That is, the resistance is zero as in the equivalent circuit of FIG.

  In the example of the aluminum wiring pattern shown in FIGS. 5A and 5B, the wiring part 400 is connected to each contact 300, and a current flows through the resistance region 200 between the contacts 300. In other words, the resistor R is connected as in the equivalent circuit of FIG.

  In the example of the aluminum wiring pattern shown in FIGS. 6A and 6B, the wiring portion 400 is connected to the contact 300, and one wiring portion 400 is connected to the contacts 300 on both sides of the one contact 300. In this configuration, current flows in parallel through the resistance region 200 between 300. That is, as shown in the equivalent circuit of FIG. 6A, the resistor R is connected in parallel, and the wiring pattern can finely set the resistance value of the adjusting resistor.

(Application Example of Bridge Circuit Offset Voltage Adjustment Structure According to Embodiment of the Present Invention to Electronic Components)
As an electronic component, an application example to an MR sensor 800 that requires highly accurate offset adjustment by adjusting a resistance value will be described.

  The MR sensor 800 detects the change in the magnetic field and the presence / absence of the magnetic substance as a voltage change by utilizing the fact that the resistance value of the resistance portion constituting the MR sensor 800 changes due to the magnetic resistance.

  FIG. 7A shows a configuration in which resistors R11, R12, R13, and R14 are bridge-connected in the horizontal and vertical directions, and (b) bridges resistors R15, R16, R17, and R18 in an orthogonal 45 degree direction. It is a circuit connection diagram which shows the connected structure.

  The power supply voltage Vcc1 is supplied to the end where the resistors R11 and R13 are connected, the end where the resistors R12 and R14 are connected is connected to the ground GND, and the output is output from the end where the resistors R11 and R12 are connected. An output voltage Vout1- is output from the end where the voltage Vout1 + and the resistors R13 and R14 are connected.

  Similarly, the power supply voltage Vcc2 is supplied to the end where the resistors R15 and R17 are connected, the end where the resistors R16 and R18 are connected is connected to the ground GND, and the end where the resistors R15 and R16 are connected. Output voltage Vout2 +, and output voltage Vout2- is output from the end where resistors R17 and R18 are connected.

  FIG. 8 is a plan view showing an MR sensor 800 as an electronic component formed by laying out the circuit connection diagram described above on the substrate 100 in a predetermined pattern and formed by a semiconductor manufacturing process. .

On the substrate 100, resistors R11 to R18 assembled in the bridge shown in FIG. 7 are formed of a predetermined resistance material. An adjustment resistor Rc is formed in a part of each of the resistors R11 to R18. The resistors R11 to R18 are formed by a known semiconductor manufacturing process using, for example, InSb, NiCo or the like. NiCo, which has a high electron mobility and is often used as an MR sensor, has a specific resistance of about 2.3 × 10 ⁻⁷ (Ω · m).

  The MR sensor 800 formed as described above selects a wiring mask pattern so that the offset of the output voltage becomes a predetermined amount or less by the wiring process in the semiconductor manufacturing process. This wiring mask pattern is, for example, a bridge circuit formed with various aluminum wiring patterns with various mask patterns on a semiconductor wafer in a prototype stage, or an electronic component (MR sensor 800) including the bridge circuit. By forming it in a TEG (Test Element Group) and measuring it, an optimal mask pattern can be selected and used in the mass production process.

  In the case of this MR sensor 800, as an example, the offset accuracy of each of the resistors R11 to R18 has an adjustment accuracy of ± 5 mV in the conventional configuration, but the adjustment resistor Rc is formed by selecting an optimal mask pattern. By doing so, it became possible to manufacture with an accuracy of ± 1 mV.

(Effect of the embodiment of the present invention)
The embodiment of the present invention has the following effects. That is, an adjustment resistor is connected to the bridge resistor constituting the bridge circuit, and the resistance value of the adjustment resistor can be appropriately changed in the wiring process in the semiconductor manufacturing process. This change is possible by selecting a wiring mask pattern. For example, a bridge circuit formed of various aluminum wiring patterns with various mask patterns or an electronic component including the bridge circuit is formed in a TEG (Test Element Group) on a semiconductor wafer in a prototype stage. By measuring this, an optimum mask pattern can be selected and used in the mass production process. This makes it possible to provide a low-cost offset voltage adjustment structure for a bridge circuit and an electronic component including the same without requiring time for adjustment.

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

DESCRIPTION OF SYMBOLS 10 ... Bridge circuit 100 ... Board | substrate 110 ... Insulating layer 200 ... Resistance region 300 ... Contact 400 ... Wiring part 500 ... Interlayer insulating film 510 ... Opening 600 ... Resist 610 ... Opening 700 ... Metal layer 800 ... MR sensor R1-R4 ... Bridge Resistors Ra, Rb, Rc ... adjusting resistors

Claims (4)

A bridge resistor formed on the substrate;
A resistance region formed on the substrate;
A plurality of contacts of three or more formed in the resistance region;
A wiring portion that electrically connects the contact and the bridge resistor;
An offset voltage adjustment structure for a bridge circuit, wherein a bridge circuit is configured by the bridge resistor and an adjustment resistor selected from the plurality of contacts by the wiring portion and connected to the bridge resistor.   The bridge circuit offset voltage adjustment structure according to claim 1, wherein the selection is performed in a manufacturing process of the wiring portion. A substrate,
A bridge resistor formed on the substrate;
A resistance region formed on the substrate;
A plurality of contacts of three or more formed in the resistance region;
A wiring portion that electrically connects the contact and the bridge resistor;
An electronic component, wherein a bridge circuit is configured by the bridge resistor and an adjustment resistor selected from the plurality of contacts by the wiring portion and connected to the bridge resistor. The electronic component according to claim 3, wherein the selection is performed in a manufacturing process of the wiring portion.

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