MEMS structure

Abstract

The present disclosure relates to a MEMS structure comprising a stator having stator comb teeth and a rotor having rotor comb teeth, where the stator comb teeth and the rotor comb teeth are interlaced with each other and form interlaced rows, and in at least some portions of the interlaced rows where the aspect ratio is expected to change abruptly, the gaps between the comb teeth are gradually increased. An advantage of the arrangement structure of the present disclosure is that an undesirable fringe effect is eliminated during the deep reactive ion etching process, and a high quality MEMS structure is achieved.

Description

Technical Field

[0001] The present disclosure relates to MEMS structures, and in particular to MEMS structures with active comb gaps. Background Art

[0002] MEMS structures such as the active comb structures of electrostatic actuators often include regions where the aspect ratio changes abruptly. Such MEMS structures are often fabricated using deep reactive ion etching (DRIE). One problem that arises when etching designed locations where the aspect ratio changes abruptly and the dimensions are close to a critical value is aspect ratio dependent etching (ARDE). ARDE can cause streaks and sidewall defects that compromise the geometry of the processed structure, can generate loose silicon particles, and degrade signal quality.

[0003] Figure 1a An example of a structure having regions where the aspect ratio changes abruptly is illustrated in . The exemplary comb structure 100 includes connected open regions 102, 103, and 104. The aspect ratio can be defined as the relationship between the height dimension in the z direction and the surface dimension in the x-direction / y-direction. The region into which regions 102-103 and region 104, which have significant width differences, merge may be a region where the aspect ratio changes abruptly. If the width of the smallest region 104 is within a critical value range, the ARDE effect in such a region may be particularly concerning. In contrast, regions 105 and 106 differ less in their widths, so the aspect ratio change in this region may not appear to be very abrupt.

[0004] One way to avoid the ARDE effect is to add protective structures 101 to the design, such as Figure 1b As shown in the figure. The guard structure helps to maintain the aspect ratio gradient under control and / or transfer the damage caused by DRIE from the active MEMS structure to the guard structure. The disadvantage of this solution is that the guard structure requires additional design space in the MEMS structure. Therefore, a solution to eliminate the ARDE effect without affecting the design space is needed. Summary of the invention

[0005] The purpose of the present disclosure is to provide a novel design of a MEMS structure to solve the above problems.

[0006] The object of the present disclosure is achieved by an arrangement structure, which is characterized by what is stated in the main aspects of the present application. Preferred embodiments of the present disclosure are disclosed in the subsidiary aspects of the present application.

[0007] The present disclosure is based on the idea that the stator and the rotor form a structure wherein the gap between the stator and the rotor increases gradually in at least a portion of the structure where an abrupt change in the aspect ratio is expected.

[0008] An advantage of the arrangement of the present disclosure is that the undesirable ARDE effect is eliminated and a high quality MEMS structure is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the following, the present disclosure will be described in more detail by means of preferred embodiments with reference to the accompanying drawings, in which:

[0010] Figure 1a An example of a structure in which the aspect ratio changes abruptly is illustrated;

[0011] Figure 1b An example of a MEMS design with a protection structure based on the prior art is illustrated;

[0012] Figure 2a A MEMS structure with a stator and a rotor of the present disclosure is illustrated;

[0013] Figure 2b illustrates a MEMS structure having staggered rows formed by pairs of adjacent stator teeth and rotor teeth;

[0014] Figure 2c illustrates a MEMS structure having end portions in staggered rows and a center portion in staggered rows;

[0015] Figure 2d illustrates a MEMS structure in which the width of the x-gaps in the end portions of the staggered rows gradually decreases;

[0016] Figure 3a illustrates a MEMS structure having a first y-gap and a second y-gap;

[0017] Figure 3b illustrates a MEMS structure having first y-gaps and second y-gaps located in end portions of staggered rows;

[0018] Figure 4a illustrates a MEMS structure having a second end portion and an x-gap;

[0019] Figure 4b illustrates a MEMS structure having a second end portion, an x-gap, and a y-gap;

[0020] Figure 5 A MEMS structure is illustrated having a stator and a rotor forming a parallel plate structure and a region where the aspect ratio varies;

[0021] Figure 5a One embodiment of a MEMS structure having a stator and a rotor forming a parallel plate structure is illustrated;

[0022] Figure 5b An embodiment of a MEMS structure is illustrated, the MEMS structure having a first end portion, a second end portion, and a central portion of a parallel plate structure;

[0023] Figure 5c One embodiment of a MEMS structure having a stator and a rotor forming a parallel plate structure is illustrated. DETAILED DESCRIPTION

[0024] The present disclosure relates to MEMS structures, and in particular to MEMS structures including combs, protrusions or other microstructures with high aspect ratios. As described above, MEMS structures can be produced using deep reactive ion etching (DRIE) techniques. MEMS structures with sizes close to a critical value are often affected by aspect ratio dependent etching (ARDE) during the DRIE process, which can have a negative impact on the quality of the manufactured structure. The areas where the ARDE effect is most affected are usually located where the aspect ratio changes suddenly, such as where a wider open area connects to a significantly narrower open area. Figure 1a The figure shows an exemplary structure in which the aspect ratio changes abruptly when regions 102 to 103 merge with region 104 .

[0025] The present disclosure proposes a solution to improve the quality of such areas. The ARDE effect can be minimized by gradually reducing the size of the etched structure from a larger size where the aspect ratio changes the most to a smaller size where the aspect ratio changes the least. The details of the invention are described below. Although the embodiments of the present disclosure mainly illustrate the comb structure of the electrostatic actuator, the same concept can be applied to other MEMS structures where the size approaches a critical value and where the aspect ratio changes abruptly.

[0026] The MEMS structure of the present disclosure includes:

[0027] A stator, the stator comprising a stator element and a row of stator teeth, wherein the stator teeth extend away from the stator element in a y direction,

[0028] a rotor comprising a rotor element and a row of rotor teeth, wherein the rotor teeth extend away from the rotor element in a direction opposite to the y-direction,

[0029] And among them,

[0030] The stator comb teeth are staggered with the rotor comb teeth to form staggered rows, and

[0031] Each pair of adjacent stator comb teeth and rotor comb teeth is spaced apart from each other by an x ​​gap in the x direction perpendicular to the y direction.

[0032] And among them,

[0033] The staggered rows include end portions, and

[0034] The staggered rows include a central portion, and the central portion and the end portions are immediately adjacent to each other, and

[0035] The width of the x gap in the central portion has a constant value, and

[0036] In the end portions of the staggered rows, the widths of the x gaps in the end portions gradually decrease so that the widths of the endmost x gaps in the end portions of the staggered rows are the largest.

[0037] Stator and rotor

[0038] like Figure 2a As illustrated in , the MEMS structure 200 of the present disclosure includes a stator 201. The stator 201 is a fixed portion of the MEMS structure 200. In other words, the stator 201 is a static portion that does not move relative to the surrounding device package when the MEMS device is in use. The stator 201 may include a stator element 202. The stator element 202 may be connected to other static portions of the MEMS structure 200. The stator 201 also includes stator teeth 203 extending away from the stator element 202. The stator teeth 203 may define a y-direction 204. The stator teeth 203 may extend parallel to the y-direction 204. The stator teeth 203 may point in the y-direction 204. The y-direction 204 may alternatively be referred to as a lateral direction.

[0039] The MEMS structure 200 of the present disclosure also includes a rotor 205. The rotor 205 is a part of the MEMS structure 200 that can move relative to the stator 201 and relative to the surrounding device package when the MEMS device is in use. In other words, the rotor 205 is the dynamic part of the MEMS structure 200. The rotor 205 can include a rotor element 206. The rotor element 206 can be, for example, a beam connected to the moving part of the MEMS structure 200. The rotor 205 also includes rotor comb teeth 207 that extend away from the rotor element 206 parallel to the y-direction 204. The rotor comb teeth 207 can point in the opposite direction to the y-direction 204. In other words, the stator comb teeth 203 and the rotor comb teeth 207 point in opposite directions. In other words, the rotor comb teeth 207 can point to the stator element 202. The stator comb teeth 203 can point to the rotor element 206.

[0040] Staggered rows and gaps

[0041] The stator comb teeth 203 are staggered with the rotor comb teeth 207. The stator comb teeth 203 and the rotor comb teeth 207 form staggered rows 208.

[0042] Each pair of adjacent stator comb teeth and rotor comb teeth is spaced apart from each other by an x ​​gap in the x-direction 210 . Figure 2a to Figure 2b A first x gap 209 is shown. The x direction 210 is perpendicular to the y direction 204. The x direction 210 may alternatively be referred to as a longitudinal direction. Thus, the x gap may alternatively be referred to as a longitudinal gap. The x gap between each pair of adjacent stator comb teeth and rotor comb teeth extends along the x direction 210 and is Figure 2a Indicated by arrows.

[0043] Figure 2b 2 shows the pairs of adjacent stator comb teeth and rotor comb teeth in more detail. For exemplary purposes, four pairs 211-214 are shown. Each adjacent stator comb tooth and rotor comb tooth can form a pair or two pairs of second teeth. Specifically, the static comb tooth 216 can form a pair 211 with the rotor comb tooth 215, and another pair 212 with the rotor comb tooth 217.

[0044] Rotor movement

[0045] The rotor 205 may be configured to move relative to the stator 201. The rotor 205 may be configured to move linearly along the x-direction 210. Specifically, the rotor 205 may be configured to move along the x-direction 210 and in a direction opposite to the x-direction 210.

[0046] In some embodiments of the present disclosure, the rotor 205 may be configured to move linearly along the y-direction 204. Specifically, the rotor 205 may be configured to move along the y-direction 204 and in a direction opposite to the y-direction 204. Alternatively, the rotor 205 may be configured to move linearly along the x-direction 210 and the y-direction 204. Alternatively, the rotor 205 may be configured to move linearly along the z-direction (not shown). The z-direction may be orthogonal to the x-direction and the y-direction.

[0047] Staggered Row Sections

[0048] like Figure 2c , the staggered rows include an end portion 218. The end portion 218 may include at least the first two pairs of adjacent stator comb teeth and rotor comb teeth. In other words, the end portion 218 may include at least three comb teeth: two stator comb teeth and one rotor comb tooth. Alternatively, the end portion 218 may include at least three comb teeth: one stator comb tooth and two rotor comb teeth. Alternatively, the end portion 218 may include at least four comb teeth, at least five comb teeth, at least six comb teeth.

[0049] The staggered row also includes a central portion 219. The central portion 219 may include other pairs of adjacent stator comb teeth and rotor comb teeth. In other words, the central portion 219 may include comb teeth of the staggered row 208 except for at least three first teeth of the end portion 218. Specifically, the central portion 219 may include more comb teeth than the end portion 218. For example, the central portion 219 may include more than 10, more than 20, more than 40, more than 50 comb teeth than the staggered row 208. The central portion 219 is adjacent to the end portion 218.

[0050] x Gap Width

[0051] Figure 2d 208. The x gaps in the end portions of the staggered row 208 may be 209 and 220-221. In the end portions of the staggered row, the widths of the x gaps in the end portions gradually decrease, so that the width of the endmost x gap in the end portions of the staggered row is the largest. The endmost x gap in the end portions of the staggered row is x gap 209.

[0052] In other words, the width of the x gap in the end portion 218 may gradually decrease as the x coordinate increases from the first comb teeth of the staggered row along the x direction. The first comb teeth of the staggered row may be rotor comb teeth, such as Figure 2d 215 in the end portion 218. Alternatively, the first comb teeth in the staggered rows may be static comb teeth (not shown). The x coordinate of the first comb teeth in the staggered rows is the smallest. The width of the x gap 209 in the end portion 218 may be greater than the width of the x gap 220. The width of the x gap 220 in the end portion 218 may be greater than the width of the x gap 221. And the width of the x gap 221 in the end portion 218 may be greater than the width of the x gap 222.

[0053] The width of the x-gap can be gradually varied from a larger value where the aspect ratio is small to a smaller value near the critical dimension where the aspect ratio is large. This gradual variation of the x-gap width can eliminate the ARDE effect discussed above and improve the geometry of the etched structure.

[0054] In the MEMS structure, a ratio between a maximum width and a minimum width of the x-gap is greater than 125%.

[0055] An exemplary width of x-gap 209 may be 5um to 8um. An exemplary width of x-gap 220-221 may be 2.5um to 3um. An exemplary width of x-gap 222-223 may be 2um to 2.5um. In other words, the width of the x-gap in end portion 218 may be gradually reduced from 8um to 2um, for example. In other words, the ratio between the maximum width of the x-gap in the end portion and the minimum width of the x-gap may be 4:1. Thus, the width of the x-gap in end portion 218 may be gradually reduced to one-fourth. Typically, the ratio between the maximum width of the x-gap in the end portion and the minimum width of the x-gap may be greater than 125%.

[0056] The x gap in the central portion 219 of the staggered row 208 may be, for example Figure 2d 222-223 as shown in FIG. The width of the x gap in the central portion 219 has a constant value. In other words, when the x coordinate changes, the width of the x gap in the central portion 219 does not change. Specifically, the width of the x gap 222 in the central portion 219 may be equal to the width of the x gap 223.

[0057] An exemplary width of the x-gap in the central portion may be 2 um. In other words, the ratio between the maximum width of the x-gap in the end portions and the width of the x-gap in the central portion may be 4:1.

[0058] Generally, the minimum width of the x-gap of the present disclosure may be close to the critical dimension of the DRIE process, which may be, for example, 2 um.

[0059] Example

[0060] An example of a comb structure is described in detail below.

[0061] In the MEMS structure, each stator comb tooth and the corresponding rotor element are spaced apart from each other by a first y gap in the y direction, and each rotor comb tooth and the corresponding stator element are spaced apart from each other by a second y gap in the y direction, and in end portions of the staggered rows, widths of the first y gap and the second y gap gradually decrease, so that in the end portions of the staggered rows, the width of the first y gap or the second y gap at the end is the largest, and in the central portion of the staggered rows, the widths of the first y gap and the second y gap have a constant value.

[0062] Figure 3a The first embodiment of the MEMS structure 200 of the present disclosure is shown. In this embodiment, a y gap may be defined between each stator tooth or rotor tooth and the opposite rotor element or stator element. Specifically, a first y gap may be defined between each static comb tooth and the opposite rotor element along the y direction, such as Figure 3aThere may be a second y gap between each rotor comb tooth and the opposite stator element along the y direction, such as Figure 3a The first y-gap and the second y-gap may alternatively be referred to as a first lateral gap and a second lateral gap.

[0063] Figure 3b The end portions 218 and a portion of the central portion 219 of this embodiment are shown in more detail. In the end portions of the staggered rows, the widths of the first y gaps and the second y gaps gradually decrease, so that in the end portions of the staggered rows, the width of the first y gap or the second y gap at the end is the largest. Figure 3b , the endmost first y gap is the first y gap 301. In other words, when the x coordinate increases from the first stator comb tooth or rotor comb tooth of the staggered row 208, such as from the first rotor comb tooth 215, the widths of the first and second y gaps 301-305 in the end portion 218 of the staggered row 208 in the y direction may gradually decrease.

[0064] The width of the first and second y gaps 301-305 in the central portion 219 in the y direction may have a constant value. In other words, when the x coordinate increases from the first stator comb tooth or rotor comb tooth of the staggered row 208, such as from the first rotor comb tooth 215, the width of the first and second y gaps 301-305 in the central portion 219 may remain constant.

[0065] In the MEMS structure, a ratio between a maximum width and a minimum width of the first y-gap and the second y-gap is greater than 125%.

[0066] An exemplary width of the first y gap and the second y gap in the end portion may be 2.5um to 10um. Specifically, the width of the first y gap 301 and the second y gap 302 may be 3.5um. The width of the first y gap 303 and the second y gap 304 may be 3um. The width of the first y gap 305 and the second y gap 306 may be 2.5um. An exemplary width of the first y gap and the second y gap in the central portion may be 2um to 6um. An exemplary width of the first y gap and the second y gap in the central portion may be 2um. In other words, the ratio between the maximum width of the first y gap and the second y gap in the end portion and the width of the first y gap and the second y gap in the central portion may be 1.75:1. Typically, the ratio between the maximum width of the first y gap and the second y gap in the end portion and the width of the first y gap and the second y gap in the central portion may be greater than 125%.

[0067] exist Figure 3a to Figure 3bIn an embodiment, when the x-coordinate increases from the first stator comb tooth or rotor comb tooth of the staggered row 208, such as from the first rotor comb tooth 215, along the x-direction, the width of both the x-gap and the y-gap in the end portion 218 can gradually decrease. In other words, when the x-coordinate increases from the starting point of the end portion 218 toward the central portion 219, the width of the gap between adjacent elements of the MEMS structure can gradually decrease. Specifically, the width of the x-gap 209 in the end portion 218 can be greater than the width of the x-gap 220. The width of the x-gap 220 in the end portion 218 can be greater than the width of the x-gap 221. And the width of the x-gap 221 in the end portion 218 can be greater than the width of the x-gap 222.

[0068] Similarly, the width of first y-gap 301 in end portion 218 may be greater than the width of first y-gap 303. The width of first y-gap 303 in end portion 218 may be greater than the width of first y-gap 305. And the width of second y-gap 302 in end portion 218 may be greater than the width of second y-gap 304. Furthermore, the width of first y-gap 301 in end portion 218 may be equal to the width of second y-gap 302. And the width of first y-gap 303 in end portion 218 may be equal to the width of second y-gap 304.

[0069] In the MEMS structure, the staggered row includes a second end portion, the second end portion has at least the last two adjacent pairs of stator comb teeth and rotor comb teeth, and wherein the second end portion is adjacent to the central portion, and wherein the width of the x gap gradually decreases in the second end portion of the staggered row, so that the width of the end-most x gap in the second end portion of the staggered row is the largest.

[0070] Figure 4a 208. The second embodiment of the present disclosure is illustrated in FIG. The MEMS structure 200 may include a second end portion 401. The second end portion 401 may include at least the last two pairs of adjacent stator comb teeth and rotor comb teeth. In other words, the second end portion 401 may be located at the end of the staggered row starting from the maximum x-coordinate. The last comb tooth may be defined as the stator comb tooth or rotor comb tooth with the largest x-coordinate in the staggered row 208. For example, the last comb tooth may be as follows: Figure 4a The stator comb teeth 402 are defined in FIG.

[0071] like Figure 4aAs shown, in the second end portion of the staggered row, the x-gap width may gradually decrease so that the width of the endmost x-gap in the second end portion of the staggered row is the largest. The endmost x-gap in the second end portion of the staggered row is 403. As the x coordinate decreases from its maximum value corresponding to the last comb tooth 402 toward the central portion 219, the width of the x-gap in the second end portion 401 may gradually decrease. Specifically, the width of the x-gap 403 to 405 may gradually decrease. The width of the x-gap 403 may be greater than the width of the x-gap 404. The width of the x-gap 404 in the second end portion 401 may be greater than the width of the x-gap 405.

[0072] In the MEMS structure, in the second end portion of the staggered row, the widths of the first y-gap and the second y-gap are gradually reduced so that the width of the endmost first y-gap or second y-gap in the second end portion of the staggered row is the largest.

[0073] Figure 4b A third embodiment of the disclosed MEMS structure 200 is illustrated. As in the previous embodiments, the MEMS structure 200 may include a second end portion 401. The second end portion 401 may include at least the last two pairs of adjacent stator comb teeth and rotor comb teeth. In other words, the second end portion 401 may be located at the end of the staggered row starting from the maximum x-coordinate. The last comb tooth may be defined as the stator comb tooth or rotor comb tooth with the largest x-coordinate in the staggered row 208. For example, the last comb tooth may be Figure 4a to Figure 4b The stator comb teeth 402 defined in .

[0074] like Figure 4b As shown, in the second end portion of the staggered row, the widths of the first y gap and the second y gap can gradually decrease, so that the width of the endmost first y gap or the second y gap in the second end portion of the staggered row is the largest. The endmost second y gap in the second end portion of the staggered row can be the second y gap 403. In other words, when the x coordinate decreases from its maximum value corresponding to the last comb tooth 402 toward the central portion 219, the widths of the first y gaps 407, 409, 411 and the second y gaps 406, 408, 410 in the second end portion 401 can gradually decrease.

[0075] Specifically, the widths of the first y gap and the second y gaps 406 to 411 may gradually decrease. The width of the first y gap 406 in the second end portion 401 may be greater than the width of the first y gap 408. The width of the first y gap 408 in the second end portion 401 may be greater than the width of the first y gap 410. In addition, the width of the second y gap 407 in the second end portion 401 may be greater than the width of the second y gap 409. The width of the second y gap 409 in the second end portion 401 may be greater than the width of the second y gap 411. In addition, the width of the first y gap 406 in the second end portion 401 may be equal to the width of the second y gap 407. The width of the first y gap 408 in the second end portion 401 may be equal to the width of the second y gap 409.

[0076] Parallel plate structure

[0077] There may also be a sudden change in aspect ratio in other rotor and stator arrangements where a larger open area is adjacent to a narrower gap. For example, a rotor and stator in the form of parallel plates may be arranged as a parallel plate electrostatic actuator. Alternatively, the rotor and stator may be separated by a raised structure that forms a narrow gap and causes a sudden change in aspect ratio. Figure 5 Regions 528 and 529 are illustrated where wider open regions (larger circles) merge with narrower open regions (smallest circles). ARDE effects in such regions may be particularly concerning if the width of the smallest region (diameter of the smallest circle) is within a critical range. Therefore, as described below, a gradual increase in aspect ratio in these regions may eliminate undesirable streaks and sidewall defects.

[0078] The MEMS structures of the present disclosure may include:

[0079] a stator comprising a stator element and at least one stator comb plate, wherein the stator comb plate extends away from the stator element in the y direction,

[0080] a rotor comprising a rotor element and at least one rotor comb plate, wherein the rotor comb plate extends away from the rotor element in a direction opposite to the y-direction,

[0081] And among them,

[0082] The stator comb plates and the rotor comb plates are parallel to each other, and the stator comb plates and the rotor comb plates form a parallel plate structure, and

[0083] The stator comb plate and the rotor comb plate are spaced apart from each other by an x ​​gap in the x direction perpendicular to the y direction.

[0084] And among them,

[0085] The parallel plate structure comprises a first end portion, which comprises at least an end of a stator comb plate,

[0086] The parallel plate structure comprises a second end portion, the second end portion comprising at least an end of the rotor comb plate, and

[0087] The parallel plate structure includes a central portion, the central portion including a region of the parallel plate structure between the stator end and the rotor end, and the central portion is located between the first end portion and the second end portion, and

[0088] The width of the x gap in the central portion has a constant value, and

[0089] The width of the x-gap in the first end portion tapers so that the width of the x-gap in the first end portion is greatest where the rotor comb plate is attached to the rotor element, and

[0090] The width of the x-gap in the second end portion tapers such that the width of the x-gap in the second end portion is greatest where the stator comb is attached to the stator element.

[0091] The MEMS structure 500 of the present disclosure includes a stator 501. The stator 501 includes a stator element 502 and at least one stator comb plate 503. The stator comb plate 503 extends away from the stator element 502 along a y-direction 504. The MEMS structure 500 of the present disclosure also includes a rotor 505. The rotor 505 includes a rotor element 506 and at least one rotor comb plate 507. The rotor comb plate 507 extends away from the rotor element 506 along a direction opposite to the y-direction 504.

[0092] The stator comb plates 503 and the rotor comb plates 507 are parallel to each other. The stator comb plates 503 and the rotor comb plates 507 form a parallel plate structure 508.

[0093] The stator comb plates 503 and the rotor comb plates 507 are spaced apart from each other by an x ​​gap (eg, 509 ) in the x direction 510 . The x direction 510 is perpendicular to the y direction 504 .

[0094] like Figure 5b As shown in FIG. 5 , the parallel plate structure 508 includes a first end portion 511. The first end portion 511 includes at least an end 512 of the stator comb plate. The end 512 of the stator comb plate can be defined as the outermost edge of the stator comb plate 503 facing the rotor element 506. The length of the first end portion 511 in the y direction can account for 1% to 45% of the length of the parallel plate structure 508 in the y direction. The first end portion 511 can account for less than 45%, less than 35%, or less than 25% of the parallel plate structure 508.

[0095] The parallel plate structure 508 also includes a second end portion 513. The second end portion 513 includes at least an end 514 of the rotor comb plate. The end 514 of the rotor comb plate can be defined as the outermost edge of the rotor comb plate 507 facing the stator element 502. The second end portion 513 can account for 1% to 45% of the parallel plate structure 508. The second end portion 513 can account for less than 45%, less than 35%, or less than 25% of the parallel plate structure 508.

[0096] The parallel plate structure 508 also includes a central portion 515, which includes an area of ​​the parallel plate structure 508 between the end 512 of the stator and the end 514 of the rotor, and the central portion 515 is located between the first end portion 511 and the second end portion 513. The length of the central portion 515 in the y direction may account for 10% to 98% of the length of the parallel plate structure 508 in the y direction. The central portion 515 may account for more than 10%, more than 20%, more than 50%, or more than 75% of the parallel plate structure 508.

[0097] The x gap in the central part is such as Figure 5b The width of 516-517 in the center portion has a constant value. In other words, when the y coordinate changes, the width of the x gap 516-517 in the center portion can remain constant. Specifically, the width of the x gap such as 516-517 in the center portion can be 2um.

[0098] The width of the x-gap in the first end portion may be gradually reduced so that the width of the x-gap in the first end portion is the largest where the rotor comb plate is attached to the rotor element. The width of the x-gap in the first end portion may be 509 where the rotor comb plate is attached to the rotor element. In other words, the widths 509 and 518 of the x-gaps in the first end portion 511 may be gradually reduced as the y coordinate decreases from the starting point of the first end portion toward the central portion 515. The starting point of the first end portion 511 is the point where the rotor comb plate 507 is attached to the rotor element 506. The starting point of the first end portion 511 is also where the y coordinate is the largest. In other words, the width of the x-gap 509 may be greater than the width of the x-gap 518. And, the width of the x-gap 518 may be greater than the width of the x-gaps 516-517 in the central portion 515. An exemplary width of the x-gap 509 may be 4 um. Therefore, the ratio of the width of the widest x-gap to the width of the narrowest x-gaps 516-517 in the first end portion 511 may be 2:1.

[0099] The width of the x-gap in the second end portion may gradually decrease so that the width of the x-gap in the second end portion is the largest where the stator comb plate is attached to the stator element. The width of the x-gap in the second end portion may be 519 where the stator comb plate is attached to the stator element. In other words, the width of the x-gaps in the second end portion 513, such as x-gaps 519-520, gradually decreases as the y coordinate increases from the starting point of the second end portion 513 toward the central portion 515. The starting point of the second end portion 513 is the point 521 where the stator comb plate 503 is attached to the stator element 502, at which the y coordinate is the smallest. In other words, the width of the x-gap 519 may be greater than the width of the x-gap 520. And, the width of the x-gap 520 may be greater than the width of the x-gaps 516-517 in the central portion 515. An exemplary width of the x-gap 519 may be 4 um. Therefore, the ratio of the width of the widest x-gap in the second end portion 513 to the width of the narrowest x-gaps 516-517 may be 2:1.

[0100] The rotor 505 may be configured to move relative to the stator 501. The rotor 505 may be configured to move linearly along the x-direction 510. Specifically, the rotor 505 may be configured to move along the x-direction 510 and a direction opposite to the x-direction 510.

[0101] The width 521 of the rotor comb plate 507 may be uniform over its entire length, such as Figure 5a to Figure 5b Alternatively, the width of the rotor comb plate 507 may be non-uniform over its entire length, such as Figure 5c For example, the width 522 of the rotor comb plate in the central portion 515 may be greater than the width 523 of the rotor comb plate in the first end portion 511 or the second end portion 513. Similarly, the width of the stator comb plate 503 may be non-uniform over its entire length, such as Figure 5a to Figure 5c For example, Figure 5c As shown, the width 524 of the stator comb in the central portion 515 may be greater than the width 525 of the stator comb in the first end portion 511 or the second end portion 513. Alternatively, the width of the stator comb 503 may be uniform throughout its length (not shown).

[0102] The gap 527 between the end 512 of the stator comb plate 503 and the rotor element 506 may be equal to the x gap 509 in the first end portion 511, as shown in FIG. Figure 5bSimilarly, the gap 526 between the end 514 of the rotor comb plate 507 and the stator element 502 can be equal to the x gap 519 in the second end portion 513. In addition, the gaps 526 and 527 can be larger than the x gaps 516-517 in the central portion 515. This arrangement structure can ensure that etching defects will not occur near the end 512 of the stator comb plate 503 and the end 514 of the rotor comb plate 507.

Claims

1. A MEMS structure comprising: A stator, the stator comprising a stator element and a row of stator teeth, wherein the stator teeth extend away from the stator element in the y direction, a rotor comprising a rotor element and a row of rotor teeth, wherein the rotor teeth extend away from the rotor element in a direction opposite to the y-direction, And among them, The stator comb teeth are staggered with the rotor comb teeth to form staggered rows, and Each pair of adjacent stator comb teeth and rotor comb teeth is spaced apart from each other by an x ​​gap in an x ​​direction perpendicular to the y direction, And among them, The staggered rows include end portions, and The staggered rows include a central portion, and the central portion and the end portion are immediately adjacent to each other, and The width of the x-gap in the central portion has a constant value, and In the end portions of the staggered rows, the widths of the x gaps gradually decrease, so that the widths of the x gaps at the endmost portions of the staggered rows are the largest.

2. The MEMS structure according to claim 1, wherein: Each static comb tooth and the corresponding rotor element are spaced apart from each other by a first y gap in the y direction, and each rotor comb tooth and the corresponding stator element are spaced apart from each other by a second y gap in the y direction, and in the end portions of the staggered rows, the widths of the first y gap and the second y gap gradually decrease so that the width of the first y gap or the second y gap at the endmost end in the end portions of the staggered rows is the largest, and wherein in the central portion of the staggered rows, the widths of the first y gap and the second y gap have a constant value.

3. The MEMS structure according to claim 1 or 2, wherein: The staggered row includes a second end portion having at least the last two adjacent pairs of the stator comb teeth and the rotor comb teeth, and wherein the second end portion is adjacent to the central portion, and wherein, in the second end portion of the staggered row, the width of the x gap gradually decreases so that the width of the x gap at the endmost in the second end portion of the staggered row is the largest.

4. The MEMS structure according to claim 3, wherein: In the second end portion of the staggered row, the widths of the first y-gaps and the second y-gaps gradually decrease, so that the width of the endmost first y-gap or the second y-gap in the second end portion of the staggered row is the largest.

5. A MEMS structure according to any preceding claim, wherein: A ratio between a maximum width and a minimum width of the x-gap is greater than 125%.

6. The MEMS structure according to claims 2 to 5, wherein: A ratio between a maximum width and a minimum width of the first y-gap and the second y-gap is greater than 125%.

7. A MEMS structure comprising: a stator, the stator comprising a stator element and at least one stator comb plate, wherein the stator comb plate extends away from the stator element in the y direction, a rotor comprising a rotor element and at least one rotor comb plate, wherein the rotor comb plate extends away from the rotor element in a direction opposite to the y-direction, And among them, The stator comb plates and the rotor comb plates are parallel to each other, and the stator comb plates and the rotor comb plates form a parallel plate structure, and The stator comb plate and the rotor comb plate are spaced apart from each other by an x ​​gap in an x ​​direction perpendicular to the y direction, And among them, The parallel plate structure comprises a first end portion, the first end portion comprising at least an end of the stator comb plate, The parallel plate structure comprises a second end portion, the second end portion comprising at least an end of the rotor comb plate, and The parallel plate structure includes a central portion, the central portion includes a region of the parallel plate structure between an end of the stator and an end of the rotor, and the central portion is located between the first end portion and the second end portion, and The width of the x-gap in the central portion has a constant value, and The width of the x-gap in the first end portion tapers such that the width of the x-gap in the first end portion is greatest where the rotor comb plate is attached to the rotor element, and The width of the x-gap in the second end portion tapers such that the width of the x-gap in the second end portion is greatest where the stator comb is attached to the stator element.

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