Micro-mechanical device

Abstract

A micromechanical device (1a), in particular a micromirror device, is proposed, which has at least a first micromechanical component (2a) and a second micromechanical component (3a). The first component (2a) and the second component (3a) are connected to one another directly or indirectly. The first micromechanical component (2a) has a first sub-body (4a) and at least one second sub-body (5a). The first sub-body (4a) extends in a first plane (20a) and the second sub-body (5a) extends in a second plane (21a), which is different from the first plane (20a). The first plane (20a) and the second plane (21a) extend parallel to one another and the first plane (20a) extends above the second plane (21a). Here, the second sub-body (5a) is arranged in a transition region to the second micromechanical component (3a). A second extension (26a) of the second sub-body (5a) in a longitudinal direction is greater than a first extension (25a) of the first sub-body (4a) in the longitudinal direction.

Description

Technical Field

[0001] This invention relates to a micromechanical device, particularly a micromirror device, and a method for manufacturing the micromechanical device. Background Technology

[0002] A micromirror device as a micromechanical device is known from document US 2018 / 0307038 A1, wherein the mirror plate and spring element are arranged in different, parallel planes and interconnected by other elements in an intermediate plane. This should reduce the dynamic deformation of the mirror element.

[0003] The problem here is that, at the right-angle transition from the mirror plate to the connecting element, a local stress peak occurs when the mirror is offset, which can cause the component to break at that edge.

[0004] Based on this prior art, the objective of this invention is to develop a micromechanical device that is more stable under dynamic loads. Summary of the Invention

[0005] To address this task, a micromechanical device according to claim 1 and a method for manufacturing a micromechanical device according to claim 15 are proposed.

[0006] Micromechanical devices particularly represent micromirror devices. Alternatively, micromechanical devices are particularly configured as micromechanical pressure sensors, micromechanical inertial sensors, or micromechanical pumps. A micromechanical device has at least a first micromechanical component and a second micromechanical component. The first and second components are directly or indirectly connected to each other. Preferably, the first and / or second micromechanical components are made of semiconductor material, especially silicon. The first micromechanical component has a first sub-body and at least one second sub-body. Here, the first micromechanical component is particularly integrally constructed. The first sub-body extends in a first plane, and the second sub-body extends in a second plane, which is different from the first plane. The first and second planes extend parallel to each other, wherein the first plane extends above the second plane. In particular, the first and second planes are horizontally extending planes. In particular, the first and second sub-body are separated from each other along a separation plane, especially a horizontal separation plane. The second sub-body is arranged in a transition region to the second micromechanical component. Here, the transition region particularly represents an indirect or direct connection region from the first micromechanical component to the second micromechanical component. Here, the second extension dimension of the second sub-body in the longitudinal direction, particularly in the second plane, is greater than the first extension dimension of the first sub-body in the longitudinal direction, particularly in the first plane. Here, the extension dimension in the longitudinal direction of the respective sub-body specifically refers to the distance from the outer edge to the outer edge of the first and second sub-body in the horizontal direction. Preferably, the first and second sub-regions at least partially overlap, and the resulting outwardly projecting step between the first and second sub-body divides the dynamic load across the two edges. Therefore, the micromechanical device withstands a higher dynamic load. Preferably, the first sub-body is centrally located above the second sub-body.

[0007] Preferably, the second micromechanical component is arranged in a third plane of the micromechanical device, which is different from the first and second planes. Here, the third plane extends parallel to the first and second planes. Therefore, the second micromechanical component functions as a carrier for the first micromechanical component.

[0008] Preferably, the first and second micromechanical components are integrally formed of silicon, particularly crystalline silicon. In this case, the second sub-body of the first micromechanical component is at least partially directly adjacent to the second micromechanical component. Correspondingly, in the transition region between the first and second micromechanical components, the two micromechanical components are not materially separated from each other. Such a micromechanical device has the following advantages in terms of manufacturing technology: for production, only a single, particularly plate-shaped, silicon substrate is required.

[0009] Alternatively, the first and second micromechanical components are preferably made of silicon. The micromechanical device additionally has at least one silicon dioxide layer. The first and second micromechanical components are connected by means of the silicon dioxide layer, particularly by material locking. Preferably, a second sub-body of the first micromechanical component is at least partially directly adjacent to the silicon dioxide layer. In the transition region between the first and second micromechanical components, the two micromechanical components are correspondingly separated from each other in terms of material.

[0010] Preferably, the micromechanical device is configured as a micromirror device. In this case, the first micromechanical component is configured as a micromirror, and the second micromechanical component is configured as a particularly elastic spring element. A challenge in designing the micromirror is achieving a large offset angle. The larger the offset angle, the greater the stress load in the spring. However, such a stress load can lead to breakage at the transition edge between the spring element and the micromirror. Through an additional step between the first and second sub-body, the resulting dynamic load is now distributed across the two edges. As a result, the micromirror device can operate at even higher offset angles.

[0011] Preferably, the shape and / or second extension dimension and / or height of the second sub-body in the longitudinal direction are selected according to a predetermined mechanical stress distribution of the micromechanical device. Preferably, the height of the second sub-body is selected relative to the first sub-body such that the stress is distributed uniformly and / or, in the case of a silicon dioxide layer, as much stress as possible is removed from the silicon dioxide layer. Preferably, the height of the second sub-body is significantly smaller than the height of the first sub-body. Preferably, the ratio of the height of the second sub-body to the height of the first sub-body is at least 1:10. Preferably, the length of the outwardly projecting step between the first and second sub-body, particularly the longitudinal extension dimension of the second sub-face of the second sub-body, is greater than the height of the second sub-body. In other words, the length of the resulting step is preferably greater than its height. Preferably, the second sub-body has a height of at least 10 μm and a maximum of 20 μm. Preferably, the length of the outwardly projecting step between the first and second sub-body, particularly the longitudinal extension dimension of the second sub-face of the second sub-body, is at least 30 μm and a maximum of 50 μm.

[0012] Preferably, the first and second sub-bodies of the first micromechanical component have rectangular cross-sections. Therefore, the step between the first and second sub-bodies also has edges, particularly 90° edges, and the outer side of the second sub-bodies extends in a sixth plane, which extends substantially perpendicular to the first and / or second planes. Alternatively, the second sub-bodies of the first micromechanical device have a first sub-face that extends at least partially in a fourth plane. This fourth plane extends obliquely to the first and / or second and / or third planes. Therefore, the step between the first and second sub-bodies may have an obliquely extending outer side, particularly concave or convex, or extending with a uniform slope.

[0013] Preferably, the second sub-body of the first micromechanical device has a second sub-face that extends in a fifth plane, particularly in the separation plane between the first and second sub-body, wherein the fifth plane extends parallel to the first and / or second and / or third planes. Therefore, the step between the first and second sub-body has a flat sub-face.

[0014] Another subject of the present invention is a method for manufacturing the previously described micromechanical devices, especially micromirror devices. Attached Figure Description

[0015] Figure 1a A first embodiment of the micromechanical device is shown.

[0016] Figure 1b A method for manufacturing micromechanical devices according to a first embodiment is shown.

[0017] Figure 2a A second embodiment of the micromechanical device is shown.

[0018] Figure 2b A method for manufacturing micromechanical devices according to a second embodiment is shown.

[0019] Figure 3a A third embodiment of the micromechanical device is shown.

[0020] Figure 3b A method for manufacturing micromechanical devices according to a third embodiment is shown. Detailed Implementation

[0021] Figure 1aA first embodiment of the micromechanical device 1a is schematically shown. Here, the micromechanical device 1a is configured as a micromirror device. The micromechanical device 1a has a first micromechanical component 2a and a second micromechanical component 3a. Here, the first component 2a and the second component 3a are indirectly connected to each other via a silicon dioxide layer 7a. The first micromechanical component 2a has a first sub-body 4a and at least one second sub-body 5a. The first sub-body 4a extends in a first plane 20a, and the second sub-body 5a extends in a second plane 21a, which is different from the first plane 20a. The first plane 20a and the second plane 21a extend parallel to each other, wherein the first plane 20a extends above the second plane 21a. The second sub-body 5a is arranged in a transition region to the second micromechanical component 3a. In this first embodiment, the second sub-body 5a of the first micromechanical component 1a is directly adjacent to the silicon dioxide layer 7a in the transition region with its lower side 31a. Here, the second extension dimension 26a of the second sub-body 5a in the longitudinal direction, particularly in the second plane 21a, is greater than the first extension dimension 25a of the first sub-body 4a in the longitudinal direction, particularly in the first plane 20a. Therefore, a step is created between the first sub-body 4a and the second sub-body 5a, which in this first embodiment has a second sub-surface 9a of the second sub-body 5a extending in the fifth plane 23a. The fifth plane 23a is here configured as a separating plane between the first sub-body 4a and the second sub-body 5a, and extends parallel to the first plane 20a and / or the second plane 21a. Here, the longitudinal extension dimension 34a of the second sub-surface 9a of the second sub-body 5a is greater than the height 33a of the second sub-body 5a. In other words, the length of the resulting step is preferably greater than its height.

[0022] The second micromechanical component 3a is arranged in a third plane 22a of the micromechanical device 1a, which is different from the first plane 20a and the second plane 21a. The third plane 22a extends parallel to the first plane 20a and the second plane 21a.

[0023] The micromirror device shown as micromechanical device 1a has a micromirror as a first micromechanical component 2a and a particularly elastic spring element as a second micromechanical component 3a.

[0024] In this first embodiment, the first sub-body 4a and the second sub-body 5a of the first micromechanical component 1a have rectangular cross-sections, such that the step between the first sub-body 4a and the second sub-body 5a has a 90° edge 32a, and such that the outer side 30a of the second sub-body 5a extends in a sixth plane, which is not shown here, and which extends substantially perpendicular to the first plane 20a and / or the second plane 21a.

[0025] Here, the height of the second sub-body 33b is chosen relative to the height 33a of the first sub-body 4a in such a way that as much stress as possible is removed from the silicon dioxide layer 7a. For this purpose, the height 33a of the second sub-body 5a is chosen to be significantly smaller than the height 33b of the first sub-body 4a. The ratio of the height 33a of the second sub-body 4a to the height 33b of the first sub-body 4a is approximately 1:10.

[0026] In this embodiment, the micromechanical device additionally has a second silicon dioxide layer 6a, which is disposed on the first subbody 4a of the first micromechanical component 2a.

[0027] Figure 1b A method for manufacturing a micromechanical device 1a is shown. In a first method step, a silicon substrate 10a, particularly a plate-shaped silicon substrate, is disposed above a second micromechanical component 3a and a silicon dioxide layer 7a. Specifically, the structure formed by the silicon substrate 10a, the silicon dioxide layer 7a, and the micromechanical component 3a is a silicon dioxide wafer. Furthermore, a first etch mask 6a, particularly an additional silicon dioxide layer, is disposed on the upper side 29a of the silicon substrate. In a subsequent method step 15a, a second etch mask 11a is applied to the first etch mask 6a. The second etch mask is, in particular, a photosensitive varnish layer. Subsequently, in method step 15b, material of the silicon substrate 10a is removed in a trench process such that a groove 12a of a defined shape is formed in the upper side of the silicon substrate 10a. In a subsequent method step 15c, a portion of the first etch mask 6a is removed in an etching step such that a sub-surface 13a of the silicon substrate 10a is exposed to the outside. In subsequent method step 15d, the material of the silicon substrate 10a is further etched downwards in a second trench process to create a first micromechanical component 2a, which has according to Figure 1a The first sub-body 4a and the second sub-body 5a. In the final method step 15e, the second etch mask 11a is removed.

[0028] Figure 2a A second embodiment of the micromechanical device 1b is shown. Unlike the first embodiment, the micromechanical device 1b here has a second sub-body 5b, the outer side 30b of which is curved, and in particular concave. Therefore, the outer side 30b, which is the first sub-face of the second sub-body, extends at least partially in a fourth plane, which is not shown here, and extends obliquely to the first plane 20a and the second plane 21a.

[0029] Here, the micromechanical device 1b is also configured as a micromirror device having a first micromechanical component 2b and a second micromechanical component 3b. The first component 2b and the second component 3b are indirectly connected to each other via a silicon dioxide layer 7a. The first micromechanical component 2b here also has a first sub-body 4b and at least one second sub-body 5b. The first sub-body 4b extends in a first plane 20a, and the second sub-body 5b extends in a second plane 21. The second sub-body 5b is arranged in the transition region to the second micromechanical component 3b. Here, the second extension dimension 26b of the second sub-body 5b in the longitudinal direction in the second plane 21a is also greater than the first extension dimension 25b of the first sub-body 4b in the longitudinal direction in the first plane 20a.

[0030] Figure 2b A method for manufacturing a micromechanical device 1b is illustrated. A silicon dioxide wafer is first provided, having a silicon substrate 10b, a second micromechanical component 3b, and a silicon dioxide layer 7b, the silicon substrate being, in particular, a plate-shaped silicon substrate. Furthermore, a first etch mask 6b is disposed on the upper side 29b of the silicon substrate. In a subsequent method step 16a, a second etch mask 11b is applied to the first etch mask 6b and the upper side 29b of the silicon substrate 10b. The second etch mask 11b is, in particular, a photosensitive varnish layer. In method step 16b, an isotropic silicon etching step follows, in which material of the silicon substrate 10a is removed such that a groove 12b of a defined shape is formed in the upper side 29b of the silicon substrate 10b. In a subsequent method step 16c, the second etch mask 11b is removed in an etching step. In subsequent method step 16d, the material of the silicon substrate 10b is further etched downwards in the trench process to create a first micromechanical component 2b, which has according to Figure 2a The first sub-subbody 4b and the second sub-subbody 5b.

[0031] Figure 3a A third embodiment of the micromechanical device 1c is shown. Unlike the first and second embodiments, the micromechanical device 1c here has a second sub-body 5c, the inclined outer side 30b of which has a uniform slope. Therefore, this outer side 30c, which is the first sub-face of the second sub-body 5c, extends entirely in a fourth plane, which is not shown here, and extends inclined to the first plane 20a and the second plane 21a.

[0032] The micromechanical device 1c is also configured as a micromirror device having a first micromechanical component 2c and a second micromechanical component 3c. The first component 2c and the second component 3c are indirectly connected to each other via a silicon dioxide layer 7a. Here, the first micromechanical component 2c also has a first sub-body 4c and a second sub-body 5c. The first sub-body 4c extends in a first plane 20a, and the second sub-body 5c extends in a second plane 21. The second sub-body 5c is arranged in the transition region to the second micromechanical component 3c. Here, the second extension dimension 26c of the second sub-body 5c in the longitudinal direction in the second plane 21a is also greater than the first extension dimension 25c of the first sub-body 4c in the longitudinal direction in the first plane 20a.

[0033] Figure 3b A method for manufacturing a micromechanical device 1c is illustrated. A silicon dioxide wafer is first provided, having a silicon substrate 10c, a second micromechanical component 3c, and a silicon dioxide layer 7c, the silicon substrate being, in particular, a plate-shaped silicon substrate. Furthermore, an additional silicon dioxide layer is disposed on the upper side 29c of the silicon substrate 10c as a first etch mask 6c. In a subsequent method step 17a, a second etch mask 11c is applied to the first etch mask 6c and the upper side 29c of the silicon substrate 10c. The second etch mask 11c is, in particular, a photosensitive varnish layer. The photosensitive varnish is applied or baked such that it has defined varnish flanks 38a in the edge regions of the second etch mask 11c. Then, in a subsequent etching step in method step 17b, these varnish flanks are transferred into the silicon body. In a subsequent method step 17c, the remainder of the second etch mask 11c is removed in a further etching step. In subsequent method step 17d, the material of the silicon substrate 10c is further etched downwards in the trench process to create a first micromechanical component 2c, which has according to Figure 3a The first sub-subbody 4c and the second sub-subbody 5c.

Claims

1. A micromechanical device (1a, 1b, 1c), said micromechanical device having at least: - First micromechanical components (2a, 2b, 2c), and - Second micromechanical components (3a, 3b, 3c). in, The first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are directly or indirectly connected to each other. The first micromechanical component (2a, 2b, 2c) has a first sub-body (4a, 4b, 4c) and at least one second sub-body (5a, 5b, 5c). The first sub-body (4a, 4b, 4c) extends in a first plane (20a), and the second sub-body (5a, 5b, 5c) extends in a second plane (21a), which is different from the first plane (20a). The first plane (20a) and the second plane (21a) extend parallel to each other, wherein the first plane (20a) extends above the second plane (21a), wherein the second sub-body (5a, 5b, 5c) is arranged in the transition region to the second micromechanical component (3a, 3b, 3c), wherein the second extension dimension (26a, 26b, 26c) of the second sub-body (5a, 5b, 5c) in the longitudinal direction is greater than the first extension dimension (25a, 25b, 25c) of the first sub-body (4a, 4b, 4c) in the longitudinal direction.

2. The micromechanical device (1a, 1b, 1c) according to claim 1, characterized in that, The second micromechanical component (3a, 3b, 3c) is arranged in a third plane (22a) of the micromechanical device (1a, 1b, 1c), the third plane being different from the first plane (20a) and the second plane (21a), wherein the third plane (22a) extends parallel to the first plane (20a) and the second plane (21a).

3. The micromechanical device (1a, 1b, 1c) according to claim 1, characterized in that, The first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are made of silicon in one piece.

4. The micromechanical device (1a, 1b, 1c) according to claim 3, characterized in that, The second sub-body (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) is at least partially directly adjacent to the second micromechanical component (3a, 3b, 3c).

5. The micromechanical device (1a, 1b, 1c) according to any one of claims 1 or 2, characterized in that, The first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are made of silicon, wherein the micromechanical device (1a, 1b, 1c) additionally has at least one silicon dioxide layer (7a, 7b, 7c), and the first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are connected by means of the silicon dioxide layer (7a, 7b, 7c).

6. The micromechanical device (1a, 1b, 1c) according to claim 5, characterized in that, The second sub-body (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) is at least partially directly adjacent to the silicon dioxide layer (7a, 7b, 7c).

7. The micromechanical device (1a, 1b, 1c) according to any one of claims 1 to 4, characterized in that, The micromechanical devices (1a, 1b, 1c) are constructed as micromirror devices, wherein the first micromechanical component (2a, 2b, 2c) is constructed as a micromirror, and the second micromechanical component (3a, 3b, 3c) is constructed as an elastic spring element.

8. The micromechanical device (1a, 1b, 1c) according to any one of claims 1 to 4, characterized in that, The shape of the second sub-body (5a, 5b, 5c) in the longitudinal direction and / or the second extended dimensions (26a, 26b, 26c) and / or the height of the second sub-body (5a, 5b, 5c) are selected according to the predetermined mechanical stress distribution of the micromechanical device (1a, 1b, 1c).

9. The micromechanical device (1a, 1b, 1c) according to any one of claims 1 to 4, characterized in that, The first sub-body (4a, 4b, 4c) and the second sub-body (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) each have a rectangular cross-section.

10. The micromechanical device (1a, 1b, 1c) according to claim 2, characterized in that, The second subbody (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) has a first subface (30b, 30c) that extends at least partially in a fourth plane, wherein the fourth plane extends at an angle to the first plane (20a) and / or the second plane (21a) and / or the third plane (22a).

11. The micromechanical device (1a, 1b, 1c) according to claim 2, characterized in that, The second sub-body (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) has a second sub-face (9a, 9b, 9c) extending in a fifth plane (23a), wherein the fifth plane (23a) extends parallel to the first plane (20a) and / or the second plane (21a) and / or the third plane (22a).

12. The micromechanical device (1a, 1b, 1c) according to claim 11, characterized in that, The longitudinal extension dimension (34a) of the second sub-face (9a, 9b, 9c) of the second sub-body (5a, 5b, 5c) is greater than the height (33a) of the second sub-body (5a, 5b, 5c).

13. The micromechanical device (1a, 1b, 1c) according to any one of claims 1 to 4, characterized in that, The height (33b) of the first sub-body (4a, 4b, 4c) is greater than the height (33a) of the second sub-body (5a, 5b, 5c).

14. The micromechanical device (1a, 1b, 1c) according to claim 13, characterized in that, The height (33a) of the second sub-body (5a, 5b, 5c) is at least 1:10 greater than the height (33b) of the first sub-body (4a, 4b, 4c).

15. The micromechanical device (1a, 1b, 1c) according to claim 1, characterized in that, The second extension dimension (26a, 26b, 26c) of the second sub-body (5a, 5b, 5c) in the second plane (21a) in the longitudinal direction is greater than the first extension dimension (25a, 25b, 25c) of the first sub-body (4a, 4b, 4c) in the first plane (20a) in the longitudinal direction.

16. The micromechanical device (1a, 1b, 1c) according to claim 3, characterized in that, The first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are integrally formed of crystalline silicon.

17. The micromechanical device (1a, 1b, 1c) according to claim 4, characterized in that, The lower side of the second sub-body (5a, 5b, 5c) of the first micromechanical component (2a, 2b, 2c) is at least partially directly adjacent to the second micromechanical component (3a, 3b, 3c).

18. The micromechanical device (1a, 1b, 1c) according to claim 5, characterized in that, The first micromechanical component (2a, 2b, 2c) and the second micromechanical component (3a, 3b, 3c) are connected by means of the silicon dioxide layer (7a, 7b, 7c) material.

19. The micromechanical device (1a, 1b, 1c) according to claim 11, characterized in that, The fifth plane (23a) is constructed as a separation plane between the first sub-body (4a, 4b, 4c) and the second sub-body (5a, 5b, 5c).

20. The micromechanical device (1a, 1b, 1c) according to claim 13, characterized in that, The total height of the first sub-body (4a, 4b, 4c) is greater than the total height of the second sub-body (5a, 5b, 5c).

21. A method for manufacturing a micromechanical device (1a, 1b, 1c) according to any one of claims 1 to 20.

22. The method according to claim 21, characterized in that, The micromechanical devices (1a, 1b, 1c) are constructed as micromirror devices.

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