MICROMECHANICAL COMPONENT FOR A SENSOR DEVICE
20220250901 · 2022-08-11
Inventors
Cpc classification
B81B3/0086
PERFORMING OPERATIONS; TRANSPORTING
B81C1/00698
PERFORMING OPERATIONS; TRANSPORTING
International classification
B81B3/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A micromechanical component for a sensor device, including a seismic mass, which is situated at and/or in a mounting and which includes a first electrode area, a second electrode area electrically insulated from the first electrode area, and a connecting area made up of at least one electrically insulating material. The first electrode area and the second electrode area each mechanically contact the connecting area and are connected to one another via the connecting area. At least one first conductive area of the first electrode area and a second conductive area of the second electrode area are structured out of a first semiconductor and/or metal layer. The first electrode area also includes a third conductive area. The second electrode area also includes a fourth conductive area. The third conductive area and the fourth conductive area are structured out of a second semiconductor and/or metal layer.
Claims
1-10. (canceled)
11. A micromechanical component for a sensor device, comprising: a mounting; and a seismic mass, which is situated at and/or in the mounting and which is deformable and/or displaceable with respect to the mount, the seismic mass including a first electrode area, a second electrode area electrically insulated from the first electrode area, and a connecting area made up of at least one electrically insulating material, each of the first electrode area and the second electrode area mechanically contacting the connecting area, and being connected to one another via the connecting area, and at least one first conductive area of the first electrode area and a second conductive area of the second electrode area being structured out of a first semiconductor and/or metal layer, wherein the first electrode area additionally includes a third conductive area mechanically contacting the first conductive area, and the second electrode area additionally includes a fourth conductive area mechanically contacting the second conductive area, the third conductive area and the fourth conductive area being structured out of a second semiconductor and/or metal layer.
12. The micromechanical component as recited in claim 11, wherein a first separating trench, structured through the first semiconductor and/or metal layer, is formed between the first conductive area and the second conductive area, and a second separating trench, structured through the second semiconductor and/or metal layer, is formed between the third conductive area and the fourth conductive area, a first center plane which extends centrally through the first separating trench being oriented in parallel to and at a distance not equal to zero to a second center plane which extends centrally through the second separating trench, a first opening of the first separating trench, which is oriented to the third conductive area and the fourth conductive area, and a second opening of the second separating trench, which is oriented to the first conductive area and the second conductive area, opening at a connecting trench which is free of material of the second semiconductor and/or metal layer, and at least the connecting trench being at least partially filled with the at least one electrically insulating material of the connecting area.
13. The micromechanical component as recited in claim 12, wherein the first separating trench, along its first center plane, and the second separating trench, along its second center plane, extend from a first side of the seismic mass to a second side of the seismic mass, the first conductive area and the second conductive area, both on the first side of the seismic mass and on the second side of the seismic mass, are each configured with a protruding separating trench edge area adjoining the first separating trench, the connecting trench adjoining the second separating trench, both on the first side of the seismic mass and on the second side of the seismic mass, in each case perforating a side wall of the third conductive area and of the fourth conductive area, respectively, and a protruding edge of the connecting area made of the at least one electrically insulating material protruding at the perforated side walls of the third conductive area and of the fourth conductive area, respectively, and the protruding edge of the connecting area covering the protruding separating trench edge areas of the first conductive area and of the second conductive area.
14. The micromechanical component as recited in claim 13, wherein the first separating trench, along its first center plane, extends from a nose area of the connecting area which protrudes on the first side of the seismic mass at the protruding edge of the connecting area and is made up of the at least one electrically insulating material, to a nose area which protrudes on the second side of the seismic mass at the protruding edge of the connecting area and is made up of the at least one electrically insulating material of the connecting area.
15. The micromechanical component as recited in claim 11, wherein each of the at least one electrically insulating material of the connecting area has an electrical conductivity of less than-equal to 10.sup.−8 S.Math.cm.sup.−1 and/or a specific resistance of greater than-equal to 10.sup.8 Ω.Math.cm.
16. The micromechanical component as recited in claim 10, wherein the at least one electrically insulating material of the connecting area is silicon-rich silicon nitride.
17. A manufacturing method for a micromechanical component for a sensor device, comprising the following steps: forming a seismic mass at and/or in a mounting of the micromechanical component in such a way that the seismic mass is deformable and/or displaceable with respect to mounting, the seismic mass being configured with a first electrode area, a second electrode area electrically insulated from the first electrode area, and a connecting area made up of at least one electrically insulating material in such a way that each of the first electrode area and the second electrode area mechanically contact the connecting area and are connected to one another via the connecting area, and at least one first conductive area of the first electrode area and a second conductive area of the second electrode area being structured out of a first semiconductor and/or metal layer; and configuring the first electrode area additionally with a third conductive area mechanically contacting the first conductive area, and configuring the second electrode area additionally with a fourth conductive area mechanically contacting the second conductive area, by structuring the third conductive area and the fourth conductive area out of a second semiconductor and/or metal layer.
18. The manufacturing method as recited in claim 17, wherein a first separating trench is structured through the first semiconductor and/or metal layer, between the later configured first conductive area and the later configured second conductive area, and a second separating trench is structured through the second semiconductor and/or metal layer between the later configured third conductive area and the later configured fourth conductive area, a first center plane which extends centrally through the first separating trench being oriented in parallel to and at a distance not equal to zero from a second center plane which extends centrally through the second separating trench, a connecting area which is free of material of the second semiconductor and/or metal layer being configured in such a way that a first opening of the first separating trench, which is oriented to the third conductive area and the fourth conductive area, and a second opening of the second separating trench, which is oriented to the first conductive area and the second conductive area, opening at the connecting trench, at least the connecting trench being at least partially filled with the at least one electrically insulating material of the connecting area.
19. The manufacturing method as recited in claim 18, wherein, after the structuring of the first separating trench with a maximum extension oriented perpendicularly to the first center plane, the at least one electrically insulating material of the later configured connecting area is deposited onto at least sub-surfaces of the later configure first conductive area and of the later configured second conductive area with a minimum layer thickness, the minimum layer thickness being greater than, by at least a factor of 2, or equal to a maximum extension of the first separating trench perpendicular to the first center plane.
20. The manufacturing method as recited in claim 18, wherein the first separating trench, a first subarea of the connecting trench situated adjoining the first opening of the first separating trench, and a second subarea of the connecting trench situated adjoining the second opening of the second separating trench are filled with at least one sacrificial material, while a residual area of the connecting trench situated between the first subarea and the second subarea is filled with the at least one electrically insulating material of the later configured connecting area, the at least one sacrificial material being at least partially removed using an etching medium, whose etching rate for the at least one sacrificial material is in each case greater by at least a factor of 2 than for the at least one electrically insulating material of the later connecting area.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Further features and advantages of the present invention are described hereafter based on the figures.
[0016]
[0017]
[0018]
[0019]
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0020]
[0021] During the manufacturing method described hereafter, a seismic mass is formed at and/or in a mounting 30 of the micromechanical component in such a way that the seismic mass is deformable and/or displaceable with respect to mounting 30. By way of example, mounting 30 in the specific embodiment described here includes/is a substrate 30 including a substrate surface 30a. Substrate 30 is preferably a semiconductor substrate, such as in particular a silicon substrate. As an alternative or in addition to silicon, however, substrate 30 may also include at least one other semiconductor material, at least one metal and/or at least one insulator.
[0022] The seismic mass is designed with a first electrode area, a second electrode area electrically insulated from the first electrode area, and a connecting area made up of at least one electrically insulating material. A first conductive area of the first electrode area and a second conductive area of the second electrode area are structured out of a first semiconductor and/or metal layer 32.
[0023] By way of example, first semiconductor and/or metal layer 32 is deposited onto at least one intermediate layer 34 at least partially covering substrate surface 30a of substrate 30 in the specific embodiment of the manufacturing method described here.
[0024]
[0025] As is illustrated in
[0026] Preferably, the at least one electrically insulating material of connecting area 40 in each case has an electrical conductivity of less than-equal to 10.sup.−8 S.Math.cm.sup.−1, or the at least one electrically insulating material has a specific resistance of greater than-equal to 10.sup.8 Ω.Math.cm. It is also advantageous when the at least one electrically insulating material in each case has an etching rate with respect to at least one etching medium which is smaller, by at least a factor of 2, than an etching rate of the at least one etching medium for the at least one sacrificial material. The at least one electrically insulating material of connecting area 40 may, e.g., be silicon-rich silicon nitride.
[0027]
[0028] Etching mask 42, perpendicular to first center plane 38, has a second maximum extension b.sub.42 which is considerably larger than second maximum extension a.sub.42 of first separating trench 36. Second maximum extension b.sub.42 of etching mask 42 may, e.g., be greater than second maximum extension b.sub.36 of first separating trench 36 by at least a factor of 5. The advantages of such a design of etching mask 42 will also become apparent based on the following figures.
[0029] Etching mask 42 is removed after the at least one electrically insulating material of connecting area 40 has been structured. Thereafter, a second semiconductor and/or metal layer 44 is deposited over first semiconductor and/or metal layer 32 and connecting area 40. Second semiconductor and/or metal layer 44 may, in particular, be a silicon layer/polysilicon layer. Instead of or in addition to silicon/polysilicon, second semiconductor and/or metal layer 44, however, may also include at least one other semiconductor material and/or at least one metal.
[0030]
[0031] With the aid of the joint structuring of first semiconductor and/or metal layer 32 and second semiconductor and/or metal layer 44, first electrode area 46a of seismic mass 48 and second electrode area 46b of seismic mass 48 are formed in such a way that first electrode area 46a also includes third conductive area 44a, in addition to first conductive area 32a, while second electrode area 46b is also formed with fourth conductive area 44b, in addition to second conductive area 32b. Moreover, first electrode area 46a and second electrode area 46b in each case mechanically contact connecting area 40, and are thus connected to one another via connecting area 40. Seismic mass 48 encompassing first electrode area 46a, second electrode area 46b and connecting area 40 therefore has a sufficient fracture resistance for use of the micromechanical component manufactured with the aid of seismic mass 48 for a sensor device.
[0032] During the joint structuring-out of conductive areas 32a, 32b, 44a and 44b, additionally a second separating trench 50 is structured through second semiconductor and/or metal layer 44 between third conductive area 44a and fourth conductive area 44b, while first separating trench 36a runs between first conductive area 32a and second conductive area 32b. Second separating trench 50 shall be understood to mean a second separating trench 50 extending through second semiconductor and/or metal layer 44. Moreover, second separating trench 50 is structured through second semiconductor and/or metal layer 44 in such a way that first center plane 38 extending centrally through first separating trench 36 is oriented in parallel to and at a distance Δ not equal to zero from a second center plane 52 extending centrally through second separating trench 50. For seismic mass 48, a first side 48a and a second side 48b may thus be defined in such a way that first separating trench 36, along its first center plane 38, and second separating trench 50, along its second center plane 52, extend from first side 48a of seismic mass 48 to second side 48b of seismic mass 48b. In addition, distance Δ is smaller than second maximum extension b.sub.42 of etching mask 42 perpendicular to first center plane 38 and second center plane 52, and is selected in such a way that second separating trench 50 extends to connecting area 40. Distance Δ between first center plane 38 and second center plane 52 is preferably greater than-equal to half the maximum layer thickness d.sub.32 of first semiconductor and/or metal layer 32 which is oriented perpendicularly to substrate surface 30a. In addition, it is advantageous when distance Δ is greater than, by at least a factor of 2, or equal to a sum of second maximum extension b.sub.36 of first separating trench 36 perpendicular to its first center plane 38, and a maximum extension b.sub.50 of second separating trench 50 perpendicular to its first center plane 52.
[0033] It is shown in
[0034] As is illustrated in
[0035] The joint structuring-out of conductive areas 32a, 32b, 44a and 44b is stopped at protruding areas 40a and 40b of connecting area 40, and at the at least one exposed sacrificial material of sacrificial layer 34. Due to protruding edges 40b of connecting area 40, first conductive area 32a and second conductive area 32b, both on first side 48a of seismic mass 48 and on second side 48b of seismic mass 48, are in each case, adjoining first separating trench 36, configured with a protruding separating trench edge area 56a and 56b (see
[0036] The formation of protruding edges 40b of connecting area 40 at seismic mass 48 facilitates the joint structuring-out of conductive areas 32a, 32b, 44a and 44b, while avoiding a short circuit at seismic mass 48. If seismic mass 48 were designed without protruding edges 40b of connecting area 40, perpendicular etching trenches including completely smooth etching walls would have to be structured over the entire height of first semiconductor and/or metal layer 32 and second semiconductor and/or metal layer 44 during the joint structuring-out, since otherwise undesirable short circuits could occur due to material residues. A design of seismic mass 48 without protruding edges 40b of connecting area 40 would necessitate a compliance with hardly realizable accuracies during the joint structuring-out of conductive areas 32a, 32b, 44a and 44b.
[0037] Despite protruding edges 40b of connecting area 40, protruding nose areas 40a of connecting areas 40 ensure that no short circuit caused by a material residue occurs in the area of one of protruding edges 40b, despite the formation of protruding edges 40b. Even when the overhang of protruding edges 40b is comparatively large, the desired potential isolation is ensured by protruding nose areas 40a of connecting area 40.
[0038]
[0039]
[0040] As is shown in
[0041] Thereafter, sacrificial material 58 is at least partially removed with the aid of an etching medium, whose etching rate for sacrificial material 58 is greater by at least a factor of 2 than for the at least one electrically insulating material of the later connecting area 40. This is illustrated in
[0042] With respect to further method steps of the manufacturing method of
[0043]
[0044] The micromechanical component schematically shown in
[0045] As is shown in
[0046] The micromechanical component of
[0047] With respect to further features and properties of the micromechanical component of
[0048] The micromechanical component of