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CN-122000204-A - Microelectromechanical component and method for producing a microelectromechanical component

CN122000204ACN 122000204 ACN122000204 ACN 122000204ACN-122000204-A

Abstract

A microelectromechanical MEMS component (100) for determining ambient and/or acoustic pressure has a parallel capacitive plate structure (101) comprising a fixed electrode (103) and a movable electrode (105), the fixed electrode comprising a first and a second fixed electrode plate (107, 109), the movable electrode comprising a first movable electrode plate (111) and a second movable electrode plate (113) connected thereto, the first and the second fixed electrode plates being spaced apart from each other in an offset direction, a first functional layer (F1) of the MEMS component being defined by the first fixed electrode plate, a second functional layer (F2) being defined by the second fixed electrode plate, the first movable electrode plate being arranged in the second functional layer and opposite the first fixed electrode plate, the second movable electrode plate being arranged in the first functional layer and opposite the second fixed electrode plate, the first and the second movable electrode plates being jointly offset from the first and the second functional layers by an offset of the movable electrode.

Inventors

  • H. G.B. Gundam
  • T. FRIEDRICH

Assignees

  • 罗伯特·博世有限公司

Dates

Publication Date
20260508
Application Date
20251104
Priority Date
20241106

Claims (16)

  1. 1. A microelectromechanical MEMS component (100) for ascertaining ambient and/or acoustic pressure, having a parallel capacitive plate structure (101), wherein the capacitive plate structure (101) comprises a fixed electrode (103) and a movable electrode (105) which is mounted offset relative to the fixed electrode (103) in an offset direction (D), wherein the fixed electrode (103) comprises a first fixed electrode plate (107) and a second fixed electrode plate (109), wherein the movable electrode (105) comprises a first movable electrode plate (111) and a second movable electrode plate (113) which is connected to the first movable electrode plate (111), wherein the first fixed electrode plate (107) and the second fixed electrode plate (109) are spaced apart from one another in the offset direction (D), wherein a first functional layer (F1) of the MEMS component (100) is defined by the first fixed electrode plate (107) and a second functional layer (F2) of the MEMS component is defined by the second fixed electrode plate (109), wherein the first movable electrode plate (111) is arranged opposite the second electrode plate (107) and the second functional layer (F2) is arranged in the first functional layer (F) and the second functional layer (F) is arranged opposite to the first functional layer (F) and the second electrode plate (113), and is arranged opposite to the second fixed electrode plate (109), wherein the first movable electrode plate (111) and the second movable electrode plate (113) can be jointly offset from the first functional layer (F1) and the second functional layer (F2) by an offset of the movable electrode (105).
  2. 2. The MEMS component (100) according to claim 1, wherein the MEMS component (100) is configured for a differential capacitance measurement method.
  3. 3. The MEMS component (100) according to claim 1 or 2, wherein a first spacing (A1) between the first fixed electrode plate (107) and the first movable electrode plate (111) increases or decreases and a second spacing (A2) between the second fixed electrode plate (109) and the second movable electrode plate (113) decreases or increases opposite to the first spacing (A1) when the movable electrode (105) is offset with respect to the fixed electrode (103).
  4. 4. The MEMS component (100) according to any of the preceding claims, wherein the movable electrode (105) is deflectable supported on the fixed electrode (103) by a spring structure (115).
  5. 5. The MEMS component (100) according to claim 4, wherein the MEMS component (100) has a frame structure (117), wherein the movable electrode (105) is connected to the frame structure (117) by the spring structure (115).
  6. 6. MEMS component (100) according to claim 4 or 5, wherein the second movable electrode plate (113) is connected to the first fixed electrode plate (107) by a first spring element (119), wherein the first movable electrode plate (111) is connected to the second fixed electrode plate (109) by a second spring element (121).
  7. 7. The MEMS component (100) according to any of the preceding claims 4-6, wherein the spring structure (115) is configured as a first spring silicon layer (123) and a second spring silicon layer (125), wherein the first spring silicon layer (123) is configured on the first fixed electrode plate (107) and the second movable electrode plate (113), wherein the second spring silicon layer (125) is configured on the second fixed electrode plate (109) and the first movable electrode plate (111).
  8. 8. The MEMS component (100) according to claim 7, wherein the first spring silicon layer (123) and the second spring silicon layer (125) fluidly close an intermediate space (127) between the fixed electrode (103) and the movable electrode (105).
  9. 9. The MEMS component (100) according to claim 8, wherein the intermediate space (127) between the fixed electrode (103) and the movable electrode (105) is vacuum.
  10. 10. The MEMS component (100) according to any of the preceding claims, wherein the first stationary electrode plate (107) and/or the second stationary electrode plate (109) has a through opening (129).
  11. 11. The MEMS component (100) according to any of the preceding claims, wherein the second stationary electrode plate (109) is fixedly connected with the frame structure (117) of the MEMS component (100) by at least one tab element (131).
  12. 12. MEMS component (100) according to any of the previous claims, wherein the stationary electrode (103) has a plurality of first stationary electrode plates (107) and/or second stationary electrode plates (109), wherein the first stationary electrode plates (107) are each arranged in the first functional layer (F1) and the second stationary electrode plates (109) are each arranged in the second functional layer (F2), wherein the movable electrode (105) has a plurality of first movable electrode plates (111) and/or second movable electrode plates (113), wherein the first movable electrode plates (111) are each arranged in the second functional layer (F2) and the second movable electrode plates (113) are each arranged in the first functional layer (F1).
  13. 13. The MEMS component (100) according to any of the preceding claims, wherein in the first functional layer (F1) first fixed electrode plates (107) and second movable electrode plates (113) are alternately arranged in a direction (D1) perpendicular to the offset direction (D), wherein in the second functional layer (F2) second fixed electrode plates (109) and first movable electrode plates (111) are alternately arranged in a direction (D2) perpendicular to the offset direction (D).
  14. 14. The MEMS component (100) according to any of the preceding claims, wherein the MEMS component (100) is configured as a capacitive pressure sensor or a capacitive microphone.
  15. 15. A method for manufacturing a MEMS component according to any of the preceding claims 1 to 14, the method comprising the steps of: Providing a substrate (133) having an oxide layer (135) and a first electrode silicon layer (137) structured on the oxide layer (135); -performing a silicon etch in the first electrode silicon layer (137) and creating at least one gap (139), wherein a first layer element (141) and a second layer element (143) are created by the gap (139) in the first electrode silicon layer (137); -applying a first spring silicon layer (123) on the first electrode silicon layer (137), wherein the first spring silicon layer (123) has a smaller layer thickness than the first electrode silicon layer (137), wherein the first layer element (141) and the second layer element (143) of the first electrode silicon layer (137) are connected to each other by the first spring silicon layer (123); -applying a further oxide layer (145) onto the first spring silicon layer (123); -performing an oxide etch in said further oxide layer (145) and creating at least one gap (147); -applying a second electrode silicon layer (149) onto the further oxide layer (145), wherein a connection between the second electrode silicon layer (149) and a first spring silicon layer (123) of the second layer element (143) covering the first electrode silicon layer (137) is achieved by the gap (147) in the further oxide layer (145); -performing a silicon etch of the second electrode silicon layer (149) and creating at least two gaps (151) in the second electrode silicon layer (149), wherein a third layer element (153), a fourth layer element (155) and a fifth layer element (157) are created by the gaps (151) in the second electrode silicon layer (149); Applying a second spring silicon layer (125) onto the second electrode silicon layer (149), wherein the second spring silicon layer (125) has a smaller layer thickness than the second electrode silicon layer (149), wherein the third to fifth layer elements (153, 155, 157) of the second electrode silicon layer (149) are connected to each other by the second spring silicon layer (125), and -Removing the substrate (133) and the oxide layer (135, 145) by means of oxide etching and back trench etching, wherein a first fixed electrode plate (107) is formed by means of the first layer element (141) and a second movable electrode plate (109) is formed by means of the second layer element (143), wherein a wall element (159) of a frame structure (117) of the MEMS component (100) is formed by means of the third layer element (153), the first movable electrode plate (111) is formed by means of the fourth layer element (155), and a second fixed electrode plate (109) is formed by means of the fifth layer element (157), wherein a spring structure (115) for displaceably supporting the movable electrode (105) is formed by means of the first spring silicon layer (123) and the second spring silicon layer (125).
  16. 16. The method of claim 15, wherein the silicon layer is configured as a polysilicon layer and is formed by a deposition process.

Description

Microelectromechanical component and method for producing a microelectromechanical component Technical Field The present invention relates to a microelectromechanical component and a method for manufacturing a microelectromechanical component. Background Microelectromechanical components, in particular MEMS capacitive pressure sensors, MEMS capacitive microphones and corresponding production methods are known from the prior art. Disclosure of Invention The object of the present invention is to provide an improved microelectromechanical component and a corresponding method for producing a microelectromechanical component. This object is achieved by a MEMS component and a method according to the invention. Advantageous embodiments are obtained from the description. According to one aspect, a MEMS component for determining ambient and/or sound pressure is provided, having a parallel capacitive plate structure, wherein the capacitive plate structure comprises a fixed electrode and a movable electrode which is mounted offset relative to the fixed electrode in an offset direction, wherein the fixed electrode comprises a first fixed electrode plate and a second fixed electrode plate, wherein the movable electrode comprises a first movable electrode plate and a second movable electrode plate which is connected to the first movable electrode plate, wherein the first fixed electrode plate and the second fixed electrode plate are spaced apart from one another in the offset direction, wherein a first functional layer of the MEMS component is defined by the first fixed electrode plate and a second functional layer of the MEMS component is defined by the second fixed electrode plate, wherein the first movable electrode plate is arranged in the second functional layer and is arranged opposite the first fixed electrode plate, wherein the second movable electrode plate is arranged in the first functional layer and is arranged opposite the second fixed electrode plate, wherein the first movable electrode plate and the second movable electrode plate can be jointly offset from the first functional layer and the second functional layer by the offset of the movable electrode plate. The following technical advantages are thereby achieved, and an improved microelectromechanical component can be provided. The microelectromechanical component (hereinafter MEMS component) here comprises a capacitive plate structure with fixed and movable electrodes. The fixed electrode comprises at least two fixed electrode plates and the movable electrode similarly comprises two movable electrode plates. The change in capacitance between the electrodes can be determined by the movement of the movable electrode plate relative to the fixed electrode plate. The fixed electrode plates, which are arranged spaced apart from each other in the offset direction of the movable electrode, define two functional layers of the MEMS member. The movable electrode plates are anyway spaced apart relative to each other in the direction of displacement and are arranged in two functional layers. By the displacement of the movable electrode, the movable electrode plate can be displaced outwardly from the first and second functional layers, whereby the distance between the movable electrode plate and the fixed electrode plate can be changed, thereby causing a change in capacitance between the electrodes. The MEMS component of the invention uses only two functional layers here, so that a simplified structure of the MEMS component can be achieved. According to one embodiment, the MEMS component is configured for use in a differential capacitance measurement method. The following technical advantages are achieved in that the ambient pressure or sound pressure can be determined precisely by means of the MEMS component by means of a differential capacitance measurement method. According to one embodiment, when the movable electrode is offset relative to the fixed electrode, a first spacing between the first fixed electrode plate and the first movable electrode plate increases or decreases, and a second spacing between the second fixed electrode plate and the second movable electrode plate decreases or increases opposite to the first spacing. Thereby, the technical advantage is achieved that a differential capacitance measurement method can be achieved by a corresponding offset of the first and second movable electrode plates of the movable electrode with respect to the first and second fixed electrode plates of the fixed electrode. When the movable electrode is offset relative to the fixed electrode, the first spacing between the first fixed electrode plate and the first movable electrode plate increases or decreases, and the second spacing between the second fixed electrode plate and the second movable electrode plate correspondingly changes in opposition to the first spacing. Two different capacitances are thereby created, thereby implementing a differential capacitance meas