CN210639270U

CN210639270U - Electric connection structure of MEMS magnetic sensor and MEMS magnetic sensor

Info

Publication number: CN210639270U
Application number: CN201921288133.8U
Authority: CN
Inventors: 邹泉波; 曹志强; 冷群文
Original assignee: Beihang University Qingdao Research Institute; Goertek Techology Co Ltd
Current assignee: Qingdao Research Institute of Beijing University of Aeronautics and Astronautics; Weifang Goertek Microelectronics Co Ltd
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-05-29
Anticipated expiration: 2029-08-08

Abstract

The utility model relates to an electric connection structure of an MEMS magnetic sensor and the MEMS magnetic sensor, which comprises a substrate and a magnetic resistance positioned on the substrate; the lead structure also comprises a first lead part, a second lead part and a third lead part, wherein the first lead part is positioned at the position of a side wall of the magnetic resistance and is contacted with the side wall of the magnetic resistance, and the contact surface of the first lead part and the side wall of the magnetic resistance is an inclined surface; the electric signal of the magnetic resistance is led out through the first lead part. The electric connection structure of the utility model can improve the contact area of the first lead part and the magnetic resistance side wall, thereby ensuring the stability of the conduction of the first lead part and the magnetic resistance; meanwhile, the problems of gaps and defects which are easy to generate during manufacturing can be reduced.

Description

Electric connection structure of MEMS magnetic sensor and MEMS magnetic sensor

Technical Field

The utility model relates to the sensing field, more specifically, the utility model relates to an electric connection structure of magnetic resistance in an MEMS magnetic sensor; the utility model discloses still relate to a MEMS magnetic sensor.

Background

The MEMS magnetic sensor is a magnetic sensor manufactured based on the MEMS process, the magnetic resistance is an important component, an electric signal of the magnetic resistance needs to be led out through a lead, and a bonding pad for external connection is formed at the exposed position of the sensor.

In the existing structure, a lead is usually connected to a side wall position of a magnetic resistance, and particularly, during manufacturing, a whole conductive layer is formed on the surface of a magnetic resistance layer in advance; patterning the conductive layer to obtain a pattern of the lead; and patterning the magnetic resistance layer to obtain the lines and the shapes of the magnetic resistance. In the magnetic sensor obtained by the process, the magnetoresistive layer at the edge of the lead cannot be completely removed due to the process, which has a non-negligible effect on the performance of the magnetic sensor.

In addition, with this sidewall conduction, the contact area of the lead and the magnetic resistance is not very large, and voids/defects that are easily generated may cause yield and reliability problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an electric connection structure of MEMS magnetic sensor.

According to an aspect of the present invention, there is provided an electrical connection structure of a MEMS magnetic sensor, comprising a substrate and a magnetic resistance on the substrate; the lead structure also comprises a first lead part, a second lead part and a third lead part, wherein the first lead part is positioned at the position of a side wall of the magnetic resistance and is contacted with the side wall of the magnetic resistance, and the contact surface of the first lead part and the side wall of the magnetic resistance is an inclined surface; the electric signal of the magnetic resistance is led out through the first lead part.

Optionally, a dielectric layer is further disposed between the substrate and the magneto-resistance.

Optionally, the dielectric layer is silicon oxide.

Optionally, a passivation layer covering the first lead portion, the magneto-resistance, and the dielectric layer; the passivation layer is provided with a through hole corresponding to the position of the first lead part, and the passivation layer further comprises a second lead part located on the passivation layer, and the second lead part is conducted with the first lead part through the through hole.

Optionally, the passivation layer is silicon nitride.

Optionally, the inclined surface of the side wall of the magnetic resistor enables the size of the magnetic resistor to be gradually larger from the bottom surface to the top surface of the magnetic resistor.

Optionally, the sloped surface of the sidewall of the magnetic resistor is such that the magnetic resistor gradually becomes smaller from the bottom surface to the top surface thereof.

Optionally, the inclined surface of the magnetic resistance side wall is formed by ion beam etching.

Optionally, the first lead portion is deposited on an edge of the magnetic resistance and combined with the inclined surface of the side wall of the magnetic resistance through a lift-off process.

According to another aspect of the present invention, there is provided a MEMS magnetic sensor, including the above-mentioned electrical connection structure.

The electric connection structure of the utility model can improve the contact area of the first lead part and the magnetic resistance side wall, thereby ensuring the stability of the conduction of the first lead part and the magnetic resistance; meanwhile, the problems of gaps and defects which are easy to generate during manufacturing can be reduced.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic view of the electrical connection structure of the present invention.

Fig. 2 is a partially enlarged view of a position where the first lead portion is fitted to the magnetic resistance in fig. 1.

FIG. 3 is a partial enlarged view of the first lead portion and another embodiment of the magnetic resistance.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: unless specifically stated otherwise, the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be considered a part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Fig. 1 illustrates an electrical connection structure of a MEMS magnetic sensor according to the present invention, which includes a substrate 1 and a magnetic resistance 3 located on the substrate 1. The magneto-resistive 3 is mass-fabricated on a wafer by a MEMS process, and the substrate 1 may be a silicon substrate known to those skilled in the art.

A dielectric layer 2 may also be provided between the substrate 1 and the magneto-resistance 3 to avoid conduction therebetween. The dielectric layer 2 may be silicon dioxide or other materials known to those skilled in the art and will not be described in detail herein.

The magnetic resistance 3 of the present invention is formed on the dielectric layer 2. Specifically, during the fabrication, the magnetoresistive structures are sequentially formed on the dielectric layer 2 by the MEMS process. For example, a plurality of magnetoresistors are formed in a matrix arrangement on a wafer. The magneto-resistance 3 of the present invention may be a giant magneto-resistance sensor (GMR), a tunnel magneto-resistance sensor (TMR), an anisotropic magneto-resistance sensor (AMR) or other magneto-resistances known to those skilled in the art, etc. The electrical performance of the detection mechanism can be ensured by obtaining the detected electrical signal using a high-sensitivity giant magnetoresistive sensor (GMR), a tunnel magnetoresistive sensor (TMR), or an anisotropic magnetoresistive sensor (AMR).

Of course, the different types of magnetoresistance differ from each other in the structure of the layers formed on the silicon substrate, and will not be described in detail here.

In the manufacturing process, a magnetoresistive layer is first formed on the dielectric layer 2, and then the magnetoresistive layer can be etched through a patterning process to form a structure and a pattern of the magnetoresistive layer 3, which belongs to the common general knowledge of those skilled in the art and will not be described in detail herein.

The utility model discloses an electric connection structure of MEMS magnetic sensor still includes first lead wire portion 4, and first lead wire portion 4 is located magnetic resistance 3's lateral wall position to with the lateral wall contact of magnetic resistance 3 together, the signal of telecommunication of magnetic resistance 3 is drawn forth through first lead wire portion 4.

As described above, the magnetic resistance 3 has a multilayer laminated structure. In a typical magnetoresistive structure, it includes an antiferromagnetic layer, a pinned layer, a free layer, and the like. After patterning of the magneto-resistance 3, the sidewalls of the layers are exposed. The first lead portion 4 is disposed at an edge position of the magnetic resistance 3 and is in contact with and conducted to a sidewall of the magnetic resistance 3. So that an electrical signal of the magnetic resistance 3 can be drawn through the first lead portion 4.

The contact surface between the first lead portion 4 and the sidewall of the magnetic resistor 3 is an inclined surface. Specifically, during the manufacturing, when the pattern of the magnetic resistance 3 is formed by etching, the sidewall of the magnetic resistance 3 is etched to form the inclined surface 30, for example, by ion beam process.

The first lead portion 4 can be deposited on the edge of the magnetic resistor 3 by a peeling process, and the first lead portion 4 is combined with the inclined surface 30 of the magnetic resistor 3, so that the first lead portion 4 is conducted with the inclined surface 30 on the side wall of the magnetic resistor 3. Such a peeling process and a deposition process are common processes in MEMS manufacturing, and are not described in detail here.

By adopting the design structure of the inclined surface, the contact area of the first lead part 4 and the side wall of the magnetic resistance 3 can be increased, so that the conduction stability of the first lead part 4 and the magnetic resistance 3 can be ensured; meanwhile, the problems of gaps and defects which are easy to generate during manufacturing can be reduced.

Fig. 2 and 3 are schematic structural diagrams illustrating two different embodiments of the magnetic resistance 3 and the first lead portion 4. Referring to fig. 2, the inclined surface 30 of the sidewall of the magnetic resistance 3 makes the size of the magnetic resistance 3 gradually larger from the bottom surface thereof to the top surface thereof. That is, the side wall of the magnetic resistance 3 is inclined from the bottom to the top thereof in such a manner as to gradually approach the center position of the magnetic resistance 3.

Referring to fig. 3, the inclined surface 30 of the sidewall of the magnetic resistance 3 makes the size of the magnetic resistance 3 gradually smaller from the bottom surface thereof to the top surface thereof. That is, the side wall of the magnetic resistance 3 is inclined from the bottom to the top thereof in such a manner as to be gradually distant from the center position of the magnetic resistance 3.

In a preferred embodiment of the present invention, the semiconductor device further includes a passivation layer 5 covering the first lead portion 4 and the magnetic resistance 3 on the dielectric layer 2. The passivation layer 5 may be silicon nitride or other materials known to those skilled in the art.

A through hole is formed in the passivation layer 5 at a position corresponding to the first lead portion 4, and a second lead portion 6 is formed on the passivation layer 5, and the second lead portion 6 is electrically connected to the first lead portion 4 through the through hole. Thereby leading the electrical signal of the magneto-resistance 3 out of the magneto-resistance sensor, i.e. to the outer surface of the passivation layer 5. The second lead portion 6 may serve as a pad for external connection.

The utility model also provides a MEMS magnetic sensor, it includes foretell electric connection structure.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for purposes of illustration and is not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An electrical connection structure of a MEMS magnetic sensor, characterized in that: comprises a substrate and a magnetic resistance positioned on the substrate; the lead structure also comprises a first lead part, a second lead part and a third lead part, wherein the first lead part is positioned at the position of a side wall of the magnetic resistance and is contacted with the side wall of the magnetic resistance, and the contact surface of the first lead part and the side wall of the magnetic resistance is an inclined surface; the electric signal of the magnetic resistance is led out through the first lead part.

2. The electrical connection structure according to claim 1, wherein: a dielectric layer is also disposed between the substrate and the magneto-resistance.

3. The electrical connection structure according to claim 2, wherein: the dielectric layer is silicon oxide.

4. The electrical connection structure according to claim 2, wherein: further comprising a passivation layer covering the first lead portion and the magnetic resistance on the dielectric layer; the passivation layer is provided with a through hole corresponding to the position of the first lead part, and the passivation layer further comprises a second lead part located on the passivation layer, and the second lead part is conducted with the first lead part through the through hole.

5. The electrical connection structure according to claim 4, wherein: the passivation layer is silicon nitride.

6. The electrical connection structure according to claim 1, wherein: the inclined surface of the magnetic resistance side wall enables the magnetic resistance to be gradually larger from the bottom surface to the top surface of the magnetic resistance.

7. The electrical connection structure according to claim 1, wherein: the inclined surface of the magnetic resistance side wall enables the size of the magnetic resistance from the bottom surface to the top surface to become smaller gradually.

8. The electrical connection structure according to claim 1, wherein: the inclined surface of the magnetic resistance side wall is formed in an ion beam etching mode.

9. The electrical connection structure according to claim 8, wherein: the first lead part is deposited on the edge of the magnetic resistance through a stripping process and is combined with the inclined surface of the side wall of the magnetic resistance.

MEMS magnetic sensor, characterized in that it comprises an electrical connection structure according to any one of claims 1 to 9.