Micro-electromechanical device

Abstract

This invention discloses a microelectromechanical device (MEMS). The MEMS includes a substrate, a dielectric layer, two conductive anchors, a MEMS structure, and at least one elastic thermistor. The substrate has a height direction and an extension direction perpendicular to the height direction. The dielectric layer is disposed on the substrate. The two conductive anchors are respectively disposed on the dielectric layer and are spaced apart from each other in the extension direction. One end of the elastic thermistor is connected to one of the conductive anchors, and the other end of the elastic thermistor is connected to one end of the MEMS structure. The other end of the MEMS structure is directly or indirectly connected to the other conductive anchor. The MEMS structure is spaced apart on the substrate by the elastic thermistors to form a predetermined gap in the height direction.

Description

Technical Field

[0001] This invention relates to a device, and more particularly to a microelectromechanical device (MEMS). Prior Technology

[0002] Existing microelectromechanical devices (MEMS) are highly sensitive to temperature during operation. When the ambient temperature changes, existing MEMS are prone to operational instability, leading to decreased performance or inaccuracies. Therefore, existing MEMS also incorporate a temperature sensor to detect the ambient temperature and compensate accordingly. However, the temperature sensor used in existing MEMS senses the ambient temperature, rather than the actual temperature measured inside the MEMS, resulting in the need to improve the accuracy of the compensation mechanism.

[0003] In addition, when existing microelectromechanical devices (MEMS) are in operation, their energy is also easily dissipated through the anchor points, resulting in energy loss.

[0004] Therefore, the inventor believed that the above-mentioned defects could be improved. So he devoted himself to research and applied scientific principles, and finally proposed an invention that is reasonably designed and effectively improves the above-mentioned defects. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a microelectromechanical device that addresses the shortcomings of the prior art.

[0006] This invention discloses a microelectromechanical device (MEMS), comprising: a substrate having a height direction and an extension direction perpendicular to the height direction; a dielectric layer disposed on the substrate; two conductive anchors disposed on the dielectric layer, the two conductive anchors being electrically isolated from the substrate through the dielectric layer, and the two conductive anchors being spaced apart from each other in the extension direction; a microelectromechanical structure (MEMS) and at least one elastic thermistor, the at least one elastic thermistor including a fixed portion and an elastic portion connected to the fixed portion, the fixed portion being connected to one of the conductive anchors, the elastic portion being connected to one end of the MEMS, and the other end of the MEMS being directly or indirectly connected to the other conductive anchor; wherein the MEMS is spaced apart on the substrate through the at least one elastic thermistor to form a first predetermined gap in the height direction.

[0007] In summary, the microelectromechanical device disclosed in the embodiments of the present invention, through the design of "the fixed part being connected to one of the conductive anchors, the elastic part being connected to one end of the microelectromechanical structure, and the other end of the microelectromechanical structure being directly or indirectly connected to another conductive anchor", and "the microelectromechanical structure being spaced on the substrate through at least one elastic thermistor to form a first predetermined gap in the extension direction", can accurately measure its own temperature and at the same time reduce the loss of energy from the anchors (e.g., the conductive anchors).

[0008] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Simple Explanation of the Diagram

[0009] Figure 1 is a plan view of the microelectromechanical device of the present invention.

[0010] Figure 2 is an enlarged schematic diagram of region II in Figure 1.

[0011] Figure 3 is a schematic cross-sectional view along section III-III of Figure 1.

[0012] Figure 4 is a cross-sectional schematic diagram of one embodiment of the microelectromechanical device of the present invention.

[0013] Figure 5 is a plan view of another embodiment of the microelectromechanical device of the present invention.

[0014] Figure 6 is a plan view of another embodiment of the microelectromechanical device of the present invention.

[0015] Figure 7 is a plan view of another embodiment of the microelectromechanical device of the present invention.

[0016] Figure 8 is a planar schematic diagram of the elastic thermistor of the present invention in another embodiment.

[0017] Figure 9 is a plan view of yet another embodiment of the microelectromechanical device of the present invention.

[0018] Figure 10 is a plan view of the microelectromechanical device of the present invention in another embodiment. Implementation

[0019] The following specific embodiments illustrate the implementation of the "microelectromechanical device" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0020] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0021] Additionally, in the following description, if it is indicated that a specific diagram is referred to or as shown in a specific diagram, it is only to emphasize that most of the relevant content in the following description appears in that specific diagram, but does not limit the following description to refer only to that specific diagram.

[0022] [First Embodiment]

[0023] Referring to Figures 1 to 7, this embodiment provides a microelectromechanical device (MEMS). As shown in Figures 1 to 3, the MEMS 100A includes a substrate 1, a dielectric layer 2 disposed on the substrate 1, two conductive anchors 3 disposed on the dielectric layer 2, a MEMS structure 4 located between the two conductive anchors 3, and at least one elastic thermistor 5. The components of the MEMS 100A and their connections are described below.

[0024] Referring to Figures 1 and 3, for ease of subsequent explanation, the substrate 1 is defined with a height direction D1 and an extension direction D2 perpendicular to the height direction D1. In this embodiment, the substrate 1 is a plate-like structure with two wide side surfaces M11 and an annular side surface M12 connecting the two wide side surfaces M11. The direction from one wide side surface M11 to the other wide side surface M11 is the height direction D1, and the extension direction of any wide side surface M11 is the extension direction D2.

[0025] Furthermore, the dielectric layer 2 is provided on one of the wide side surfaces M11 of the substrate 1. In practice, the dielectric layer 2 may be an oxide layer deposited on the substrate 1, but the present invention is not limited thereto. In addition, in this embodiment, the dielectric layer 2 has two insulating portions 21 arranged at intervals from each other in the extending direction D2.

[0026] Referring again to Figures 1 to 3, two conductive anchor points 3 are respectively disposed on two insulating portions 21 of the dielectric layer 2, and the two conductive anchor points 3 can be disposed on the substrate 1 through the two insulating portions 21. Furthermore, the two conductive anchor points 3 are arranged at intervals from each other in the extending direction D2.

[0027] As shown in Figures 1 to 3, the microelectromechanical structure 4 and the at least one flexible thermistor 5 are disposed between the two conductive anchor points 3. The at least one flexible thermistor 5 connects the microelectromechanical structure 4 and one of the conductive anchor points 3, causing the microelectromechanical structure 4 to be suspended relative to the substrate 1, and allowing the at least one flexible thermistor 5 to sense temperature via direct conduction.

[0028] Specifically, the at least one elastic thermistor 5 includes a fixed portion 51 and an elastic portion 52 connected to the fixed portion 51. The fixed portion 51 is connected to one of the conductive anchor points 3, the elastic portion 52 is connected to one end of the microelectromechanical structure 4, and the other end of the microelectromechanical structure 4 is directly or indirectly connected to another conductive anchor point 3. Accordingly, the microelectromechanical structure 4 is spaced on the substrate 1 by the at least one elastic thermistor 5 to form a first predetermined gap G1 in the height direction D1. It should be noted that, since the microelectromechanical structure 4 does not contact the substrate 1 (that is, the microelectromechanical structure 4 is suspended relative to the substrate 1), the microelectromechanical structure 4 can reduce the energy dissipation from the anchor points through the stretching or compressive deformation of the elastic portion 52 in the extension direction D2.

[0029] In practice, the microelectromechanical structure 4 can also move within the first predetermined gap G1 by the tensile or compressive deformation generated by the elastic portion 52 in the height direction D1. The predetermined gap G1 needs to have a distance to prevent the microelectromechanical structure 4 from colliding with the substrate 1. Preferably, the first predetermined gap G1 is not less than 1 micrometer to ensure that the microelectromechanical structure 4 has sufficient buffer space.

[0030] Of course, when the microelectromechanical structure 4 and the at least one elastic thermistor 5 of the microelectromechanical device 100A are designed to be covered and sealed by a cover plate, a second predetermined gap G2 in the height direction D1 may also be present between the microelectromechanical structure and the cover plate to avoid the microelectromechanical structure 4 colliding with the cover plate. Specifically, as shown in FIG4, the microelectromechanical device 100B further includes a cover layer 6 (e.g., polycrystalline silicon), which covers and seals the two conductive anchors 3, the microelectromechanical structure 4, and the at least one elastic thermistor 5. The cover layer 6 and the microelectromechanical structure 4 have the second predetermined gap G2, and the second predetermined gap G2 is preferably not less than 1 micrometer.

[0031] In practice, the elastic portion 52 of the at least one elastic thermistor 5 is a meandering conductor with an elastic margin. In other words, the meandering conductor has multiple short segments A1 and multiple long segments A2 that are not parallel to the short segments A1, with the length LA2 of each long segment A2 being greater than the length LA1 of the short segments A1. The multiple long segments A2 are arranged parallel to each other and spaced apart, and the multiple short segments A1 are connected to the two ends of the multiple long segments A2 in an alternating manner, so that the multiple short segments A1 and the multiple long segments A2 form the elastic portion 52.

[0032] To facilitate understanding, the following example illustrates that "the plurality of short segments A1 are connected to the plurality of long segments A2 in an alternating manner." The plurality of long segments A2 have an opposite first common side (e.g., the elastic portion 52 on the left side in FIG2) and a second common side (e.g., the elastic portion 52 on the right side in FIG2), and the plurality of long segments A2 are defined as a first long segment A2, a second long segment A2, ..., an Nth long segment A2, and the plurality of short segments A1 are defined as a first short segment A1, a second short segment A1, ..., an N-1th short segment A1. Wherein, the end of the first long segment A2 located on the first common side is connected to the end of the second long segment A2 located on the first common side and is connected to the first short segment A1; the end of the second long segment A2 located on the second common side is connected to the end of the third long segment A2 located on the second common side and is connected to the second short segment A1; the end of the third long segment A2 located on the first common side is connected to the end of the fourth long segment A2 located on the first common side and is connected to the third short segment A1, and so on.

[0033] Accordingly, the at least one elastic thermistor 5 can have the fixing part 51 for fixing to the conductive anchor 3 and the elastic part 52 that can be stretched or compressed, so that the microelectromechanical structure 4 can have its temperature directly measured (by conduction) through the at least one elastic thermistor 5, and can avoid energy loss through the elastic part 52.

[0034] In other words, any thermistor that does not simultaneously possess the functions of "directly measuring the temperature of the microelectromechanical structure 4 and providing vibration damping for the microelectromechanical structure 4" is not the elastic thermistor 5 referred to in this invention. Furthermore, the elastic thermistor 5 of this invention detects temperature by measuring the characteristic of its resistance changing with temperature, and this measurement method is a technique known to those skilled in the art and will not be specifically described here.

[0035] In practice, the at least one flexible thermistor 5 can also be other flexible parts that do not have a meandering conductor. For example, in the microelectromechanical device 100D shown in FIG6, the flexible thermistor 5 adjacent to the microelectromechanical structure 4 is a closed and flexible conductor as the flexible part.

[0036] Furthermore, as shown in Figure 8, the connection position between the fixed part 51 and the elastic part 52 can also be designed to be off-center from the center of the elastic thermistor 5, depending on the requirements.

[0037] In addition, it is worth mentioning that, in order to ensure that the at least one elastic thermistor 5 has an ideal shock absorption effect, the width of the meandering conductor (i.e., the width WA1 of each of the short segments A1 and the width WA2 of each of the long segments A2) is preferably not less than 2 micrometers, the total length of the meandering conductor (i.e., the sum of the lengths LA1 of the plurality of short segments A1 and the lengths LA2 of the plurality of long segments A2) is not less than 400 micrometers, and the length LA2 of each of the long segments A2 is between 10 and 150 micrometers, but the present invention is not limited thereto.

[0038] In one embodiment, the number of the at least one elastic thermistor 5 may be two, the elastic portion 52 of the two elastic thermistors 5 is connected to both ends of the microelectromechanical structure 4, and the fixed portion 51 of the two elastic thermistors 5 is respectively connected to the two conductive anchor points 3 (as shown in the microelectromechanical device 100A in FIG1).

[0039] In another embodiment, the number of the at least one elastic thermistor 5 can be one, one end of the microelectromechanical structure 4 is connected to one of the conductive anchors 3 through the elastic thermistor 5, and the other end of the microelectromechanical structure 4 is fixed to another conductive anchor 3 (as shown in the microelectromechanical device 100C in FIG5).

[0040] Referring again to Figures 1 to 3, in this embodiment, the material of the microelectromechanical structure 4 is the same as that of the at least one elastic thermistor 5, and the microelectromechanical structure 4 is directly connected to the at least one elastic thermistor 5, thereby ensuring that the temperature of the microelectromechanical structure 4 can be instantly conducted to the at least one elastic thermistor 5. It is worth noting that the resistivity of the microelectromechanical structure 4 is preferably different from the resistivity of the at least one elastic thermistor 5, and the resistance value of the at least one elastic thermistor 5 is not less than 100 ohms.

[0041] Furthermore, the microelectromechanical structure 4 can be, for example, a resonator, and includes a coupling beam 41, two contacts 42 located at the center of the coupling beam 41, and two coupling rings 43 connecting the coupling beam 41. The two contacts 42 can connect to the elastic portions 52 of the two elastic thermistors 5 (as shown in Figure 1), or the two contacts 42 can respectively connect the elastic portion 52 of the elastic thermistor 5 and the conductive anchor 3 (as shown in Figure 5).

[0042] In order for the microelectromechanical structure 4 to effectively reduce energy loss, the center points of the fixed part 51, the two contact points 42 and the center points of each elongated segment A2 are preferably passed through a center line P of the microelectromechanical device 100A along the extension direction D2, but the present invention is not limited thereto.

[0043] For example, as shown in Figures 9 and 10, the center points of the two contacts 42 are passed through by the center line P, and the center points C of the plurality of elongated segments A2 are located on both sides of the center line P, that is, the center points of the plurality of elongated segments A2 are not passed through by the center line P. Furthermore, for the vibration damping effect of the microelectromechanical structure 4 connecting the at least one elastic thermistor 5 (and the conductive anchor 3), a predetermined length PL of each contact 42 along the coupling beam 41 to any one of the coupling rings 43 is preferably 1 / 4 of the wavelength corresponding to an operating frequency applicable to the microelectromechanical device, and the width W42 of each contact 42 is less than 15% of the predetermined length PL.

[0044] It should be noted that the microelectromechanical structure 4 described in this invention is not limited to a resonator. For example, as shown in FIG7, the microelectromechanical device 100E, the microelectromechanical structure 4 can also be, for example, a gyroscope, and the number of the conductive anchor 3 and the elastic thermistor 5 can each be four.

[0045] Of course, although the microelectromechanical structure 4 is a resonator, the number of the conductive anchor 3 and the elastic thermistor 5 can also be adjusted as needed (as shown in the microelectromechanical device 100D in Figure 6).

[0046] [Technical Effects of the Embodiments of the Invention]

[0047] In summary, the microelectromechanical device disclosed in the embodiments of the present invention, through the design of "the fixed part being connected to one of the conductive anchors, the elastic part being connected to one end of the microelectromechanical structure, and the other end of the microelectromechanical structure being directly or indirectly connected to another conductive anchor", and "the microelectromechanical structure being disposed on the substrate at least once by the elastic thermistor to form a first predetermined gap in the height direction", can accurately measure its own temperature and at the same time reduce the dissipation of energy from the anchor (e.g., the conductive anchor).

[0048] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

[0049] 100A~100G: Microelectromechanical devices 1:Substrate M11: Wide Side M12: Ring side 2: Dielectric layer 21: Insulation section 3: Conductive anchor point components 4: Microelectromechanical structures 41: Coupled beam 42:Contact 43: Coupling ring 5: Flexible thermistor 51: Fixed parts 52: Elastic parts A1: Short segment A2: Long Section 6: Covering layer D1: Height Direction D2: Extension direction G1: First predetermined gap G2: Second pre-determined gap WA1, WA2, W42: Width LA1, LA2: Length P: Centerline PL: Pre-determined length

Claims

1. A microelectromechanical device, comprising: A substrate having a height direction and an extension direction perpendicular to the height direction; A dielectric layer is disposed on the substrate; Two conductive anchors are disposed on the dielectric layer and on the substrate through the dielectric layer, and the two conductive anchors are spaced apart from each other in the extending direction; a microelectromechanical structure (MEMS) and at least one elastic thermistor, the at least one elastic thermistor including a fixed portion and an elastic portion connected to the fixed portion, the fixed portion being connected to one of the conductive anchors, the elastic portion being connected to one end of the MEMS, and the other end of the MEMS being directly or indirectly connected to the other conductive anchor; wherein the MEMS is spaced apart on the substrate through the at least one elastic thermistor to form a first predetermined gap in the height direction.

2. The microelectromechanical device as claimed in claim 1, wherein, The number of the at least one elastic thermistor is two, the elastic part of the two elastic thermistors is connected to both ends of the microelectromechanical structure, and the fixed part of the two elastic thermistors is respectively connected to the two conductive anchors.

3. The microelectromechanical device as claimed in claim 1, wherein, The elastic portion is a meandering conductor with an elastic margin, and the width of the meandering conductor is not less than 2 micrometers.

4. The microelectromechanical device as claimed in claim 1, wherein, The elastic portion is a meandering conductor with an elastic margin, and the total length of the meandering conductor is not less than 400 micrometers.

5. The microelectromechanical device as claimed in claim 1, wherein, The elastic portion is a meandering conductor with elastic margin, the meandering conductor having a plurality of short segments and a plurality of long segments that are not parallel to the plurality of short segments, each of the long segments being longer than the short segments, one of the short segments forming the fixed portion, and the remaining plurality of short segments and the plurality of long segments forming the elastic portion; wherein the length of each of the long segments is between 10 and 150 micrometers.

6. The microelectromechanical device as claimed in claim 1, wherein, The microelectromechanical device is suitable for an operating frequency; the microelectromechanical structure includes a coupling beam, two contacts located at the center of the coupling beam, and two coupling rings connecting the coupling beam, wherein a predetermined length of any of the contacts along the coupling beam to any of the coupling rings is 1 / 4 of the wavelength corresponding to the operating frequency, and the width of each contact is less than 15% of the predetermined length.

7. The microelectromechanical device as claimed in claim 1, wherein, The first predetermined gap is not less than 1 micrometer.

8. The microelectromechanical device as claimed in claim 1, wherein, The number of the at least one elastic thermistor is one, one end of the microelectromechanical structure is connected to one of the conductive anchors through the elastic thermistor, and the other end of the microelectromechanical structure is fixed to another conductive anchor.

9. The microelectromechanical device of claim 1, further comprising a cover layer covering the two conductive anchors, the microelectromechanical structure, and the at least one elastic thermistor, wherein the cover layer and the microelectromechanical structure have a second predetermined gap in the height direction, the second predetermined gap being not less than 1 micrometer.

10. The microelectromechanical device as claimed in claim 1, wherein, The microelectromechanical device (MEMS) has a centerline along the extending direction; the elastic portion is a meandering conductor with elastic margin, the meandering conductor having multiple short segments and multiple long segments that are not parallel to the multiple short segments, each of the long segments being longer than the short segments, one of the short segments forming the fixed portion, and the remaining multiple short segments and multiple long segments forming the elastic portion; the MEMS structure includes a coupling beam, two contacts located at the center of the coupling beam, and two coupling loops connecting the coupling beam; the center point of each of the long segments and the center point of the two contacts are passed through by the centerline.

11. The microelectromechanical device as claimed in claim 1, wherein, The microelectromechanical device (MEMS) has a centerline along the extending direction; the elastic portion is a meandering conductor with elastic margin, the meandering conductor having multiple short segments and multiple long segments that are not parallel to the multiple short segments, each of the long segments being longer than the short segments, one of the short segments forming the fixed portion, and the remaining multiple short segments and multiple long segments forming the elastic portion; the MEMS structure includes a coupling beam, two contacts located at the center of the coupling beam, and two coupling loops connecting the coupling beam; the center points of the two contacts are passed through by the centerline, and the center points of the multiple long segments are located on both sides of the centerline.

12. The microelectromechanical device as claimed in claim 1, wherein, The resistivity of the microelectromechanical structure is different from the resistivity of the at least one elastic thermistor.

13. The microelectromechanical device as claimed in claim 12, wherein, The resistance value of the at least one elastic thermistor is not less than 100 ohms.

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