SEMICONDUCTOR MEMS STRUCTURE AND METHOD FOR FORMING SAME

Abstract

The present disclosure, in some embodiments, relates to a MEMS (microelectromechanical systems) structure. The MEMS structure includes a first comb structure having a plurality of first comb fingers extending outward from a first leg. A second comb structure has a plurality of second comb fingers extending outward from a second leg. The plurality of first comb fingers are laterally interposed between the plurality of second comb fingers. The plurality of first comb fingers each includes a weighted core material and one or more peripheral materials. The weighted core material has a greater density than the one or more peripheral materials.

Description

REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over preliminary US patent application No. 63 / 636,905, filed on April 22, 2024, which is incorporated by reference into the present application. BACKGROUND

[0002] Microelectromechanical systems, or MEMS, are a technology that integrates miniaturized mechanical and electromechanical elements onto a single chip. MEMS devices are often manufactured using microfabrication techniques. In recent years, MEMS devices have found a wide range of applications. They are found in portable devices (e.g., accelerometers, gyroscopes, digital compasses), pressure sensors (e.g., impact sensors), microfluidic elements (e.g., valves, pumps), optical switches (e.g., mirrors), and more. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Aspects of this disclosure are best understood with reference to the following detailed description in conjunction with the accompanying figures. It should be noted that, in accordance with industry practice, various features are not shown to scale. In fact, the dimensions of the various features may have been arbitrarily enlarged or reduced for the sake of clarity. Fig. Figures 1A-1B illustrate some embodiments of a MEMS (microelectromechanical systems) structure with a drive actuator for a weighted comb. Fig. Figures 2A-2B illustrate some additional embodiments of a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 3A-3B illustrate cross-sectional views of some additional embodiments of MEMS structures with a drive actuator for a weighted comb. Fig. Figures 4A-4C illustrate some additional embodiments of a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 5A-5B illustrate some additional embodiments of a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 6A-6C illustrate cross-sectional views of some additional embodiments of MEMS structures with a drive actuator for a weighted comb. Fig. Figures 7A-7B illustrate some additional embodiments of a comb region of a disclosed MEMS structure. Fig. Figures 8A-8D illustrate some additional embodiments of a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 8E-8F illustrate top views of some alternative embodiments of a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 9-26 illustrate cross-sectional views of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 27-44 illustrate cross-sectional views of some additional embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 45-60 illustrate cross-sectional views of some additional embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Fig. Figures 61-76 illustrate cross-sectional views of some additional embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Fig. Figure 77 illustrates a flowchart of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. DETAILED DESCRIPTION

[0004] The following disclosure provides many different embodiments, or examples, for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first structural element over or on top of a second structural element in the following description may include embodiments in which the first and second structural elements are formed in direct contact, and may also include embodiments in which additional structural elements may be formed between the first and second structural elements, such that the first and second structural elements might not be in direct contact. Additionally, the present disclosure may repeat reference numbers and / or letters in the various examples.This repetition serves the purpose of simplification and clarity and does not itself imply any relationship between the different embodiments and / or configurations discussed.

[0005] Furthermore, spatially relative terms such as "underlying", "below", "under", "overlying", "above", and the like may be used herein to facilitate description and to describe the relationship of one element or structural element to another element(s) or structural element(s), as illustrated in the figures. These spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0006] Many modern cameras use image sensors to convert light into electrical signals. These image sensors are typically arranged in pixel arrays. Each pixel array is configured to receive incoming light, and based on this light, the camera can capture an image. However, camera movement during operation can cause light initially falling on one pixel array to travel to an adjacent one, resulting in image blur. As camera resolution increases, the size of the pixel arrays decreases, making motion-induced blur (e.g., hand shake) more noticeable in the captured images.

[0007] Image stabilization technology is a technology that reduces blur associated with movement of an image sensor during exposure. Optical image stabilization (OIS) is a form of image stabilization technology that can be used to reduce blur caused by unintentional camera movement (e.g., camera shake). OIS detects camera movement and then compensates for it by controlling an optical path between a subject and an image sensor. Some cameras may have OIS systems with an integrated image sensor chip (image sensor IC) mounted on a MEMS actuator. The MEMS actuator may include a comb-drive actuator configured to move the image sensor IC in such a way as to compensate for camera movement, ensuring that light consistently hits the same pixel area of ​​the image sensor, even if movement occurs.

[0008] An optical image stabilization (OIS) system can, for example, use sensors to detect movements of an image sensor IC (e.g., pan, tilt, vibration, etc.). When vibrations are detected, the OIS system can generate a signal that is fed into a comb drive actuator. This signal causes the comb drive actuator to vibrate in the opposite direction to the detected vibration, thus stabilizing the image sensor and improving image sharpness. However, it has been found that extreme camera movements can cause large vibrations to act on the image sensor IC, which are difficult to compensate for with current MEMS actuators. Therefore, an actuator that exhibits both strong and stable vibrations is desirable to counteract such strong vibrations.

[0009] The present disclosure relates to a MEMS (microelectromechanical systems) structure with a comb drive actuator comprising multiple comb fingers, each weighted to achieve a relatively large mass. In some embodiments, the multiple comb fingers may each contain both a core material and a weighted core material. The weighted core material has a higher density than the core material, thus increasing the overall mass (e.g., weight) of the multiple comb fingers. The increased mass of the multiple comb fingers enhances their inertia during movement, enabling them to vibrate with a relatively large amplitude and / or in a stable manner, thereby improving the performance of the comb drive actuator.

[0010] Fig. Figure 1A illustrates a top view of some embodiments of a MEMS structure 100 with a drive actuator for a weighted comb.

[0011] The MEMS structure 100 has a first comb structure 102a and a second comb structure 102b. The first comb structure 102a is separated from the second comb structure 102b along a first direction 108 and along a second direction 110, which is perpendicular to the first direction 108. The first comb structure 102a has several first comb fingers 104a extending outwards along the first direction 108 from a first leg 106a extending along the second direction 110. The second comb structure 102b has several second comb fingers 104b extending outwards along the first direction 108 from a second leg 106b extending along the second direction 110. The several first comb fingers 104a are inserted between the several second comb fingers 104b along the second direction 110.

[0012] The multiple first comb fingers 104a and / or the multiple second comb fingers 104b contain one or more peripheral materials 112 surrounding a weighted core material 114. The weighted core material 114 has a greater density and / or weight than the corresponding one or more peripheral materials 112. In some embodiments, the density ratio of the weighted core material 114 to the density of one or more peripheral materials 112 may be greater than approximately 5:1, greater than approximately 8:1, or other similar values. In some embodiments, the one or more peripheral materials 112 may contain and / or be polysilicon, a dielectric, and / or the like. In some embodiments, the weighted core material 114 may contain and / or be a metal such as tungsten, platinum, gold, tantalum, etc.

[0013] In some embodiments, the first leg 106a and / or the second leg 106b may also contain one or more peripheral materials 112 surrounding the weighted core material 114. In such embodiments, the presence of the weighted core material 114 within the first leg 106a and / or the second leg 106b may further improve the stability of the movement of the first comb structure 102a and the second comb structure 102b. In other embodiments (not shown), the first leg 106a and / or the second leg 106b may not contain the weighted core material 114 in order to weaken capacitive coupling between the first comb structure 102a and the second comb structure 102b.In some such embodiments, the first leg 106a and / or the second leg 106b may contain one or more peripheral materials 112 that extend continuously between opposite sides of the first leg 106a and / or the second leg 106b.

[0014] Fig. Figure 1B illustrates a cross-sectional view 116 of the first ridge structure 102a (e.g. along cross-sectional line AA' of Fig. 1A). As shown in cross-sectional view 116, the one or more peripheral materials 112 cover one or more sides of the weighted core material 114. In some embodiments, the one or more peripheral materials 112 contact the weighted core material 114 along the second direction 110 and along a third direction 118, which is perpendicular to the first direction 108 and the second direction 110. In some embodiments, the one or more peripheral materials 112 can extend continuously around an outer circumference of the weighted core material 114 in cross-sectional view 116. In other embodiments (not shown), the one or more peripheral materials 112 can extend with interruption along an outermost edge or several outermost edges of the weighted core material 114 in cross-sectional view 116.

[0015] In some embodiments, the one or more peripheral materials 112 can have different thicknesses along horizontally and vertically extending surfaces of the weighted core material 114. For example, the one or more peripheral materials 112 can have a greater thickness along horizontally extending surfaces (e.g., above and below the weighted core material 114) than along vertically extending surfaces (e.g., to the right and left of the weighted core material 114). In other embodiments, the one or more peripheral materials 112 can have substantially the same thicknesses along horizontally and vertically extending surfaces of the weighted core material 114.

[0016] The greater density and / or weight of the weighted core material 114 provides a relatively higher weight for the multiple first comb fingers 104a and / or the multiple second comb fingers 104b (e.g., a weight higher than that of a finger without the weighted core material 114). This relatively higher weight can provide the MEMS structure 100 with a greater amplitude and / or more stable vibrations, which can improve the operation of the MEMS structure 100. For example, in some embodiments, the multiple first comb fingers 104a and the multiple second comb fingers 104b can move relative to each other in response to a detected vibration of the MEMS structure 100. The greater amplitude and more stable vibrations provided by the disclosed MEMS structure 100 are capable of counteracting large-magnitude vibrations of the MEMS structure 100.

[0017] In some embodiments, within a comb finger, the ratio of the cross-sectional area of ​​one or more peripheral materials 112 (e.g., polysilicon) to the cross-sectional area of ​​the weighted core material 114 (e.g., a metal such as tungsten) can be in a range between approximately 1:2 and approximately 1:4, between approximately 1:3 and approximately 1:4, or other similar values. A cross-sectional area ratio between approximately 1:2 and approximately 1:4 provides increased weighting of the comb fingers, improving the performance of the MEMS structure 100, while weakening capacitive coupling between the first comb structure 102a and the second comb structure 102b.

[0018] Fig. Figure 2A illustrates a top view of some additional embodiments of a MEMS structure 200 with a drive actuator for a weighted comb.

[0019] The MEMS structure 200 has a comb section 202 comprising an anchored comb segment 204 and a mobile comb segment 206 (e.g., a test mass). The anchored comb segment 204 and the mobile comb segment 206 each have several comb fingers that are nested together. The mobile comb segment 206 is coupled to a frame section 210 by a beam section 208, which has several beams 208c and several hinges 208h. In some embodiments, the frame section 210 surrounds the comb section 202 in a continuous loop (e.g., an unbroken loop).

[0020] Fig. Figure 2B illustrates a cross-sectional view 212 of some embodiments of a MEMS structure (e.g. along cross-sectional line AA'). Fig. 2A) with a drive actuator for a weighted comb.

[0021] As shown in cross-sectional view 212, the MEMS structure has a substrate 213 with a comb region 202, a beam region 208, and a frame region 210. The MEMS structure has multiple comb fingers 104 within the comb region 202. Each of the multiple comb fingers 104 has a dielectric cover 218 surrounding a core material 214 and a weighted core material 216. In some embodiments, the dielectric cover 218 extends continuously in a closed loop around the core material 214 and the weighted core material 216.

[0022] In some embodiments, the ratio of a width 220 to a height 221 corresponding to the multiple comb fingers 104 can be in a range between approximately 1:50 and approximately 1:150, in a range between approximately 1:80 and approximately 1:120, approximately 1:100, or other similar values. In some embodiments, the multiple comb fingers 104 can each have a width 220 greater than approximately 1 micrometer, approximately equal to 1.5 micrometers, greater than approximately 1.5 micrometers, greater than approximately 5 micrometers, approximately 10 micrometers, greater than approximately 10 micrometers, or the like. In some embodiments, the multiple comb fingers 104 can each have a height 221 that is approximately 100 micrometers, approximately 150 micrometers, greater than approximately 150 micrometers, approximately 200 micrometers, greater than approximately 200 micrometers, or other similar values.

[0023] In some embodiments, the multiple comb fingers 104 can be separated by a gap 222 that is smaller than the width 220. For example, the gap 222 can be approximately 5 micrometers, less than approximately 5 micrometers, or the like. In some embodiments, the ratio of the width 220 to the gap 222 is less than or equal to approximately 2:1. With a ratio of the width 220 to the gap 222 that is less than or equal to approximately 2:1, the amplitude and stability of vibrations of the MEMS structure are further improved.

[0024] In some embodiments, the dielectric cover 218 may contain an oxide (e.g., silicon oxide), a nitride (e.g., silicon nitride), a carbide (e.g., silicon carbide), and / or the like. In some embodiments, the core material 214 may contain a semiconductor material, such as polysilicon. In some embodiments, the weighted core material 216 may contain a metal or metal alloy containing iron, cobalt, nickel, tungsten, aluminum, copper, gold, silver, and / or the like. In some embodiments (not shown), the weighted core material 216 may have several different metal layers. For example, the weighted core material 216 may have a first metal layer (containing, for example, tungsten), a second metal layer (containing, for example, iron), and so on. In some embodiments, the second metal layer may be in vertical contact with the first metal layer.In some additional embodiments, the second metal layer can touch the first metal layer both laterally and vertically.

[0025] In some embodiments, the weighted core material 216 can have a greater density than the core material 214. For example, the weighted core material 216 can have a density that is more than approximately 500% greater than that of the core material 214. For example, in some embodiments, the core material 214 can have a density that is less than approximately 5 g / cm³. 3 , less than approximately 3 g / cm² 3 , approximately 2.8 g / cm³ 3 or other similar values. In some embodiments, the weighted core material 216 may have a density greater than approximately 10 g / cm³. 3 , more than approximately 15 g / cm² 3 , approximately 19.3 g / cm³ 3 or other similar values.

[0026] In some embodiments, the volume of the core material 214 can be larger than the volume of the weighted core material 216 within the corresponding multiple comb fingers 104. In other embodiments, the volume of the core material 214 can be smaller than the volume of the weighted core material 216 within the corresponding multiple comb fingers 104. In some embodiments, the volume of the core material 214 can be greater than 1 / 3 of the volume of the weighted core material 216. The volume of the core material 214 cannot be less than approximately 1 / 3 of the volume of the weighted core material 216, or the capacity of the comb structure may be impaired, thereby reducing the performance of the MEMS structure.

[0027] In some embodiments, a conductive cap 224 can be arranged over one or more of the multiple comb fingers 104. The conductive cap 224 is vertically separated from the one or more fingers by a non-zero distance 226. During operation, a voltage differential can be provided between the conductive cap 224 and the one or more fingers to generate vertical movement within the multiple comb fingers 104. One or more conductive connectors 228 are also arranged within the frame area 210. In some embodiments, the conductive cap 224 and / or the one or more conductive connectors 228 can contain a metal such as aluminum, copper, and / or the like.

[0028] Fig. Figure 3A illustrates a cross-sectional view of some additional embodiments of a MEMS structure 300 with a drive actuator for a weighted comb.

[0029] The MEMS structure 300 comprises a substrate 213 with a comb region 202, a beam region 208, and a frame region 210. In some embodiments, the substrate 213 comprises a first semiconductor body 302 and a second semiconductor body 304 separated by a dielectric structure 306. In some embodiments, the first semiconductor body 302 has sidewalls forming one or more cavities 308a-308b. For example, the first semiconductor body 302 may have sidewalls forming a first cavity 308a within the beam region 208 and the frame region 210, and a second cavity 308b within the frame region 210.

[0030] Fig. Figure 3B illustrates a cross-sectional view of some additional embodiments of MEMS structure 310 with a drive actuator for a weighted comb.

[0031] The MEMS structure 300 comprises a substrate 213 with a comb region 202, a bar region 208, and a frame region 210. In some embodiments, the substrate 213 comprises a first semiconductor body 302 and a second semiconductor body 304, which are separated by a dielectric structure 306. In some embodiments, the dielectric structure 306 extends from between the first semiconductor body 302 and the second semiconductor body 304 along opposite outermost sidewalls of the first semiconductor body 302 and the second semiconductor body 304.

[0032] The dielectric structure 306 can laterally contact a peripheral core material 312, which is arranged along opposite sides of the first semiconductor body 302 and the second semiconductor body 304. In some embodiments, a lower dielectric 316 can be arranged beneath a base of the dielectric structure 306. In some embodiments, a peripheral first semiconductor layer 314 (which, for example, contains polysilicon) can extend continuously along the outermost sidewalls of the dielectric structure 306 and beneath a base of the lower dielectric 316. In some embodiments, an additional dielectric 318 can cover opposite outermost sidewalls and a bottom surface of the peripheral first semiconductor layer 314.

[0033] An upper semiconductor layer 320 is arranged above the dielectric cover 218 within the frame area 210. One or more conductive connectors 228 are also arranged within the frame area 210. The one or more conductive connectors 228 extend continuously from outside the upper semiconductor layer 320 to vertically above the upper semiconductor layer 320. In some embodiments, the one or more conductive connectors 228 are vertically separated from the upper semiconductor layer 320 by the additional dielectric 318. An upper dielectric 322 is arranged over portions of the one or more conductive connectors 228 and over a conductive cap 224 within the comb area 202.

[0034] Fig. Figure 4A illustrates a top view of some embodiments of MEMS structure 400 with a drive actuator for a weighted comb.

[0035] The MEMS structure 400 has a comb section 202 comprising an anchored comb segment 204 and a mobile comb segment 206 (e.g., a test mass) nested together. The mobile comb segment 206 is coupled to a frame section 210 by a beam section 208, which has multiple beams 208c and multiple joints 208h. In some embodiments, the frame section 210 surrounds the comb section 202 in a continuous and uninterrupted loop. In some embodiments, the frame section 210 can have a central frame 402 and an outer frame 404. The central frame 402 can be coupled to the mobile comb segment 206 by the multiple beams 208c and further coupled to the outer frame 404 by one or more conductive connectors 228.

[0036] Fig. Figure 4B illustrates a cross-sectional view of some additional embodiments of a disclosed MEMS package 406 along cross-sectional line AA' of Fig. 4A.

[0037] The MEMS package 406 comprises a MEMS structure 401 arranged on a base substrate 408. The MEMS structure 401 includes the comb region 202, the middle frame 402, and the outer frame 404. The middle frame 402 is freely suspended between the comb region 202 and the outer frame 404. In some embodiments, the base substrate 406 may include a printed circuit board. In some embodiments, the outer frame 404 may be electrically coupled to the base substrate 408 by several wire bonds 412.

[0038] The outer frame 404 is fixed to the base substrate 410 by one or more first bonding structures 410a. The comb area 202 is also fixed to the base substrate 410 by one or more second bonding structures (not shown). An image sensor IC 414 is coupled to the middle frame 402. In some embodiments, the image sensor IC 414 may be fixed to the middle frame 402 by one or more third bonding structures 410c. The image sensor IC 414 has one or more pixel areas, each comprising an image capture element configured to convert electromagnetic radiation (e.g., visible light, ultraviolet radiation, or the like) into an electrical signal. In some embodiments, the image sensor IC 414 may comprise a CMOS (complementary metal-on-oxide) image sensor. In some embodiments, the image acquisition element may include a photodiode, a photodetector, or the like.In some embodiments, the image sensor IC 414 can be coupled to the central frame 402 by several wire bonds 416.

[0039] In various embodiments, the one or more first bonding structures 410a, the one or more second bonding structures, and / or the one or more third bonding structures 410c may comprise an epoxy, an adhesive, conductive structures (e.g., solder bumps, vertical wire bonds, a wire pin, or the like), a polymer, and / or the like. In some additional embodiments, the one or more first bonding structures 410a, the one or more second bonding structures, and / or the one or more third bonding structures 410c may comprise a conductive structure (e.g., a vertical wire bond) surrounded by an encapsulating agent (e.g., an epoxy resin, an epoxy resin with filler, epoxy acrylate, a polymer, or the like).

[0040] Fig. Figure 4C illustrates a cross-sectional view of some additional embodiments of a disclosed MEMS package 418.

[0041] The MEMS package 418 comprises a MEMS structure 401, which includes the comb area 202, the center frame 402, and the outer frame 404. The outer frame 404 is fixed to the base substrate 408 by one or more first bonding structures 410a. The comb area 202 is fixed to the base substrate 408 by one or more second bonding structures 410b. An image sensor IC 414 is coupled to the center frame 402 by one or more third bonding structures 410c.

[0042] In some embodiments, the MEMS structure 401 and the image sensor IC 414 are arranged in a package box (e.g., a camera module). In such embodiments, the package box has a housing 420 that surrounds the MEMS structure 401 and the image sensor IC 414. In some embodiments, the housing 420 is attached to the base substrate 408. During operation, the central frame 402 can move relative to the comb area 202 and / or the outer frame 404. For example, an unwanted movement of the package box can cause a focal point of an optical system 422 to move, resulting in incident radiation 424 striking different pixel areas within the image sensor IC 414. The MEMS structure 401 is configured to move the image sensor IC 414 in response to unwanted movements of the package box, in order to reduce the effects of movement on the image sensor IC 414 (e.g.The blurring of an image is reduced to minimize the movement of incident radiation 424 between pixels) and thus stabilize an image before it is captured by the image sensor IC 414. For example, when vibrations of the image sensor IC 414 are detected, a signal is applied to the anchored comb segment and / or the movable comb segment. The signal vibrates the movable comb segment and the image sensor IC 414 to attenuate the effects of the vibration (e.g., in a direction opposite to the direction of the camera shake, thereby stabilizing an image captured by the image sensor IC 414).

[0043] Fig. Figure 5A illustrates a top view of a MEMS structure 500 with a drive actuator for a weighted comb.

[0044] The MEMS structure 500 has a comb region 202 comprising an anchored comb segment 204 and a mobile comb segment 206, which are nested together. The mobile comb segment 206 is coupled to a frame region 210 by a beam region 208, which has multiple beams 208c and multiple joints 208h. In some embodiments, the frame region 210 surrounds the comb region 202 in a continuous and uninterrupted loop. In some embodiments, the frame region 210 can have a central frame 402 and an outer frame 404. The central frame 402 can be coupled to the mobile comb segment 206 by the multiple beams 208c and further coupled to the outer frame 404 by one or more conductive connectors 228.

[0045] Fig. Figure 5B illustrates a cross-sectional view of some embodiments of a MEMS structure 502 with a drive actuator for a weighted comb along cross-sectional line AA' of Fig. 5A.

[0046] The MEMS structure 502 has a comb region 202 with multiple comb fingers 104. Each of the multiple comb fingers 104 contains a core material 214 and a weighted core material 216. In some embodiments, the core material 214 can comprise a lower core material 214a and an upper core material 214b. The weighted core material 216 is arranged vertically between a top surface of the lower core material 214a and a bottom surface of the upper core material 214b.

[0047] A dielectric cover 218 extends continuously in a closed loop surrounding the core material 214 and the weighted core material 216. In some embodiments, the core material 214 and the weighted core material 216 may have opposing outermost sidewalls that laterally contact the dielectric cover 218. In some embodiments, the core material 214 and the weighted core material 216 may have maximum widths that are substantially equal.

[0048] A conductive cap 224 is located over the multiple comb fingers 104, and one or more conductive connectors 228 are located over the frame area 210. In some embodiments, an upper dielectric 322 may be arranged over the conductive cap 224. In some embodiments, the upper dielectric 322 may also be arranged over part, but not all, of the one or more conductive connectors 228. In such embodiments, the upper dielectric 322 has side walls that are arranged directly over the one or more conductive connectors 228.

[0049] It is clear that in different embodiments the disclosed core material and weighted core material can be arranged within weighted comb fingers in different configurations. Fig. Figures 6A-6C illustrate some embodiments of comb fingers with different configurations of weighted core material. The embodiments of Fig. 6A-6C are not limiting embodiments, but merely examples.

[0050] Fig. Figure 6A illustrates a cross-sectional view of some embodiments of a MEMS structure 600 with a drive actuator for a weighted comb.

[0051] The MEMS structure 600 has a comb area 202 with multiple comb fingers 104. Each of the multiple comb fingers 104 contains a core material 214 and a weighted core material 216. In some embodiments, the core material 214 can extend in a closed loop surrounding the weighted core material 216.

[0052] A dielectric cover 218 extends continuously in a closed loop surrounding the core material 214 and the weighted core material 216. In some embodiments, the core material 214 separates the weighted core material 216 both laterally and vertically from the dielectric cover 218. In some embodiments, the core material 214 has a greater maximum width than the weighted core material 216. In some embodiments, the core material 214 may have a non-uniform thickness along different edges of the weighted core material. For example, the core material 214 may have a greater thickness along opposite outermost sidewalls of the weighted core material 216 than along the top and bottom surfaces of the weighted core material 216.

[0053] Fig. Figure 6B illustrates a cross-sectional view of some embodiments of a MEMS structure 602 with a drive actuator for a weighted comb.

[0054] The MEMS structure 602 has a comb region 202 with multiple comb fingers 104. Each of the multiple comb fingers 104 contains a core material 214 and a weighted core material 216. In some embodiments, a bottom surface of the weighted core material 216 can be arranged above a top surface of the core material 214. A dielectric cover 218 extends continuously in a closed loop surrounding the core material 214 and the weighted core material 216. In some embodiments, the dielectric cover 218 contacts both the core material 214 and the weighted core material 216 laterally and vertically. In some embodiments, the core material 214 and the weighted core material 216 have maximum widths that are substantially equal.

[0055] Fig. Figure 6C illustrates a cross-sectional view of some embodiments of a MEMS structure 604 with a drive actuator for a weighted comb.

[0056] The MEMS structure 604 has a comb region 202 with multiple comb fingers 104. Each of the multiple comb fingers 104 contains a core material 214 and a weighted core material 216. In some embodiments, a bottom surface of the core material 214 can be arranged above a top surface of the weighted core material 216. A dielectric cover 218 extends continuously in a closed loop surrounding the core material 214 and the weighted core material 216. In some embodiments, the dielectric cover 218 contacts both the core material 214 and the weighted core material 216 laterally and vertically. In some embodiments, the core material 214 and the weighted core material 216 have maximum widths that are substantially equal.

[0057] Fig. Figure 7A illustrates a top view of some additional embodiments of a MEMS structure 700 with a drive actuator for a weighted comb.

[0058] The MEMS structure 700 has a frame area 210 that surrounds a comb area 202 and a beam area 208. The frame area 210 has a central frame 402 and an outer frame 404. The central frame 402 is coupled to the outer frame 404 by one or more conductive connectors 228.

[0059] In some embodiments, the outer frame 404 has several different frame segments. Each of these different frame segments has a latch 702 that connects the different frame segments of the outer frame 404. In some embodiments, the latch 702 can have a first outer frame segment that includes a spring-loaded segment which can be inserted into a cavity of an adjacent outer frame segment to lock the outer frame segments together in a fixed relationship.

[0060] The central frame 402 is coupled to the comb area 202 by a beam 208c. In some embodiments, the beam 208c may have a joint 208h which includes a shock-absorbing section.

[0061] Fig. Figure 7B illustrates a cross-sectional view 706 of some additional embodiments of a comb region of a disclosed MEMS structure (e.g. along cross-sectional line 704 of Fig. 7A).

[0062] As shown in cross-sectional view 706, the comb region 202 has several comb fingers 104. Each of the several comb fingers 104 has a dielectric cover 218 surrounding a core material 214 and a weighted core material 216. In some embodiments, the core material 214 may have a tapered width that increases from an upper surface of the core material 214. In some other embodiments (not shown), the weighted core material 216 may have a tapered width that increases from an upper surface of the weighted core material 216. In some embodiments, the dielectric cover 218 has horn segments 218a arranged along upper outer edges of the dielectric cover 218. The horn segments 218a project outward from an upper central surface 218c of the dielectric cover 218.In some embodiments (not shown), the finger structures in the beam and / or frame area may also have horn segments.

[0063] A conductive cap 224 is located over the multiple comb fingers 104. The conductive cap 224 has tapered legs that alternately contact the multiple comb fingers 104. In some embodiments, the tapered legs contact the upper central surface 216c and are set back from opposite edges of the upper central surface 216c by a non-zero distance. In some embodiments, an upper dielectric 322 is located over the conductive cap 224.

[0064] In some embodiments, the conductive cap 224 can have a multilayered structure in which several layers are stacked on top of each other. For example, in some embodiments, the conductive cap 224 can have a first layer 224a, a second layer 224b stacked on top of the first layer 224a, and a third layer 224c stacked on top of the second layer 224b. In some embodiments, the first layer 224a can contain a metal, the second layer 224b can contain a metal nitride, and the third layer 224c can contain a metal. For example, the first layer 224a can contain tantalum (Ta), the second layer 224b can contain tantalum nitride (TaN), and the third layer 224c can contain aluminum copper (AlCu). In some embodiments, the third layer 224c can enclose a cavity 708 located above one of the several comb fingers 104 below it.

[0065] Fig. Figures 8A-8C illustrate some additional embodiments of a MEMS structure with a drive actuator for a weighted comb.

[0066] Fig. Figure 8A illustrates a three-dimensional view of a MEMS structure 800, which has a first comb structure 102a and a second comb structure 102b. The first comb structure 102a and the second comb structure 102b each have multiple comb fingers 104 extending outwards from a leg 106 and nested together. The multiple comb fingers 104 each have a core material 214 surrounding a weighted core material 216 and a dielectric cover 218 surrounding the core material 214.

[0067] The multiple comb fingers 104 each have a conically tapered width that decreases away from a connected leg 106.

[0068] Fig. Figures 8B-8C illustrate cross-sectional views, 802 and 812, which are located at various points along the multiple comb fingers 104 in Fig. 8A were recorded.

[0069] Fig. Figure 8B illustrates a cross-sectional view 802, which at a first point 802' along the several comb fingers 104 in Fig. 8A was recorded. The core material 214 in cross-sectional view 802 has a first core material width 804 and a first core material thickness 806 along a side wall of the weighted core material 216. The weighted core material 216 has a first weighted core material width 808 and a first weighted core material height 810.

[0070] Fig. Figure 8C illustrates a cross-sectional view 812, which is shown at a second location 812' along the several comb fingers 104 in Fig. 8A was recorded. The core material 214 in cross-sectional view 812 has a second core material width 814 and a second core material thickness 816 along a side wall of the weighted core material 216. The weighted core material 216 has a second weighted core material width 818 and a second weighted core material height 820.

[0071] Because the multiple comb fingers have tapered widths, the first core material width 804 is smaller than the second core material width 814. For example, the first core material width 804 can be less than or equal to approximately 1 micrometer (µm), and the second core material width 814 can be less than or equal to approximately 4 µm. The first core material thickness 806 is also smaller than the second core material thickness 816. For example, the first core material thickness 806 can be less than or equal to approximately 0.5 µm, and the second core material thickness 816 can be less than or equal to approximately 3 µm. The first weighted core material width 808 is also smaller than the second weighted core material width 818. For example, the first weighted core material width 808 can be less than or equal to approximately 1 µm and the second weighted core material width 818 can be less than or equal to approximately 4 µm.The first weighted core material height 810 is also smaller than the second weighted core material height 820. For example, the first weighted core material height 810 can be less than or equal to approximately 2 µm and the second weighted core material height 820 can be less than or equal to approximately 6 µm.

[0072] Fig. Figure 8D illustrates a top view of the MEMS structure (822). Fig. 8A. In some embodiments, the multiple first comb fingers 104a and / or the multiple second comb fingers 104b may each have a length 824 along a first direction 108 and a width 826 along a second direction 110. The length 824 may be in a range between approximately 10 micrometers and approximately 20 micrometers, approximately equal to 16 micrometers, or other similar values. The width 826 may be in a range between approximately 0.5 micrometers and approximately 2 micrometers, approximately equal to 1 micrometer, or other similar values. In some embodiments, the first comb structure 102a and / or the second comb structure 102b may be separated along the first direction 108 by a space 828, which is in a range between approximately 2 micrometers and approximately 8 micrometers, approximately equal to 5 micrometers, or other similar values.In some embodiments, the first comb structure 102a and / or the second comb structure 102b may be separated along the second direction 110 by a space 830, the size of which is in a range between approximately 1 micrometer and approximately 2 micrometers, approximately equal to 1.6 micrometers, or other similar values. In some embodiments, the ratio of the length 824 to the space 828 may be in a range between approximately 4:1 and approximately 2:1, greater than 3:1, approximately 3:1, or other similar values. In some embodiments, the ratio of the width 826 to the space 830 may be in a range between approximately 1:1 and approximately 1:2, greater than 1:1.5, approximately 1:1.6, or other similar values.

[0073] Although the top view 822 of Fig. Figure 8D illustrates the multiple first comb fingers 104a and / or the multiple second comb fingers 104b with equal lengths and widths. It is clear that in some embodiments the multiple first comb fingers 104a and / or the multiple second comb fingers 104b may have different widths and / or different lengths. For example, Figure 8D illustrates the multiple first comb fingers 104a and / or the multiple second comb fingers 104b having the same lengths and / or widths. Fig. Figure 8E shows a top view 832 of an exemplary MEM structure with multiple first comb fingers 104a and / or multiple second comb fingers 104b of different lengths. The multiple first comb fingers 104a have a first length 834 and the multiple second comb fingers 104b have a second length 836, which is shorter than the first length 834. Fig. Figure 8F illustrates a top view 838 of an exemplary MEM structure with multiple first comb fingers 104a and / or multiple second comb fingers 104b with different widths. For example, the multiple first comb fingers 104a have a first width 840 and the multiple second comb fingers 104b have a second width 842, which is smaller than the first width 840.

[0074] Fig. Figures 9-26 illustrate cross-sectional views 900-2600 of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Although the cross-sectional views 900-2600, which are shown in Fig. As shown in 9-26, and described in relation to a procedure, it is clear that the structures shown in Fig. shown in 9-26 are not limited to the process of formation, but are rather independent, separate from the process.

[0075] As shown in cross-sectional view 900 of Fig. As shown in Figure 9, a first semiconductor body 302 is provided. In various embodiments, the first semiconductor body 302 can be any type of substrate (e.g., silicon, SiGe, SOI, etc.), such as a semiconductor wafer, as well as any type of semiconductor and / or epitaxial layers associated with it. The first semiconductor body 302 has a first side 302a and a second side 302b, which is opposite the first side 302a. The first semiconductor body 302 also has a comb region 202, a bar region 208, and a frame region 210.

[0076] As shown in cross-sectional view 1000 of Fig. As shown in Figure 10, several cavities 308 are formed in the first side 302a of the first semiconductor body 302. The several cavities 308 are formed by side walls and a recessed surface of the first semiconductor body 302. In some embodiments, the several cavities 308 can be formed by selectively exposing the first side 302a of the first semiconductor body 302 to an etchant 1002 in accordance with a mask 1004. In some embodiments, the etchant 1002 can be a dry etchant (e.g., comprising fluorine, chlorine, and / or the like). In some embodiments, the mask 1004 can be a photosensitive material (e.g., a photoresist), a hard mask, and / or the like.

[0077] As shown in cross-sectional view 1100 of Fig. As shown in Figure 11, the first semiconductor body 302 is bonded to a second semiconductor body 304 to form a substrate 213. The second semiconductor body 304 has a first side 304a and a second side 304b, which faces opposite the first side 304a. In some embodiments, a first dielectric layer 306a is formed along the first side 302a of the first semiconductor body 302. The first semiconductor body 302 is then bonded to the second side 304b of the second semiconductor body 304 by the first dielectric layer 306a. In various embodiments, the second semiconductor body 304 can be any type of substrate (e.g., silicon, SiGe, SOI, etc.), such as a semiconductor wafer, as well as any other type of semiconductor and / or epitaxial layers associated with it.

[0078] In some embodiments, the first dielectric layer 306a can be formed by a heat oxidation process, such as a wet heat oxidation process or a dry heat oxidation process. In such embodiments, the first semiconductor body 302 is placed in a furnace and heated to a temperature typically ranging from approximately 800 degrees Celsius (°C) to approximately 1200 °C in the presence of oxygen to form the first dielectric layer 306a. In other embodiments, the first dielectric layer 306a can be formed by a spin deposition process, a plasma vapor deposition process (PVD process), a chemical vapor deposition process (CVD process), an atomic layer deposition process (ALD process), or other techniques.In some embodiments, the second semiconductor body 304 is bonded to an upper surface of the first dielectric layer 306a by a fusion bonding process.

[0079] As shown in cross-sectional view 1200 of Fig. As shown in Figure 12, several grooves 1202 are formed along the first side 304a of the second semiconductor body 304. The multiple grooves 1202 are formed by side walls and a recessed surface of the second semiconductor body 304. In some embodiments, the multiple grooves 1202 can be formed by selectively exposing the first side 304a of the second semiconductor body 304 to an etchant 1204 in accordance with a mask 1206. In some embodiments, the etchant 1204 can comprise a dry etchant (e.g., comprising fluorine, chlorine, and / or the like). In some embodiments, the mask 1206 can comprise a photosensitive material (e.g., a photoresist), a hard mask, and / or the like.

[0080] In some embodiments, the multiple trenches 1202 can be formed such that they have a width greater than approximately 5 µm, approximately 10 µm, greater than approximately 10 µm, or the like. In some embodiments, the multiple trenches 1202 can be separated by a distance that is smaller than their width. For example, the multiple trenches 1202 can be separated by a distance that is approximately equal to 5 µm, less than approximately 5 µm, or the like.

[0081] As shown in cross-sectional view 1300 of Fig. As shown in Figure 13, a dielectric lining 306b is formed along the inner surfaces of the second semiconductor body 304, which form the multiple grooves 1202. In some embodiments, the dielectric lining 306b is formed such that it extends continuously from within the multiple grooves 1202 to opposite outermost side walls of the first semiconductor body 302, the first dielectric layer 306a, and / or the second semiconductor body 304.

[0082] In some embodiments, the dielectric lining 306b can contain an oxide (e.g., silicon oxide), a nitride (e.g., silicon nitride), or the like. In some embodiments, the dielectric lining 306b can be formed by a thermal oxidation process. In such embodiments, the first semiconductor body 302 and the second semiconductor body 304 can be exposed to a high temperature (e.g., higher than or equal to approximately 700°C, higher than or equal to approximately 800°C, between approximately 900°C and approximately 1100°C, or other similar values). In some embodiments, the first semiconductor body 302 and the second semiconductor body 304 can be exposed to the high temperature in the presence of water vapor.

[0083] A lower core material layer 1304 is subsequently formed on the dielectric lining 306b. In some embodiments, the lower core material layer 1304 may contain a semiconductor material, such as polysilicon or the like. The lower core material layer 1304 can be formed by a deposition process on the dielectric lining 306b and within the multiple grooves 1202. In various embodiments, the deposition process may include a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like.

[0084] As shown in cross-sectional view 1400 of Fig. Figure 14 shows the lower core material layer (e.g., 1304 of Fig. 13) recessed to form a lower core material 214a located at a non-zero distance 1402 below a top surface of the dielectric lining 306b. In some embodiments, the lower core material 214a may also be recessed below a top surface of the second semiconductor body 304. In some embodiments, the lower core material 214a may be recessed by exposing the lower core material layer (e.g., 1304 of Fig. 13) a deepening is achieved using an etchant 1404, which has high etch selectivity. The high etch selectivity etches the lower core material layer without significantly etching the dielectric lining 306b, thus deepening the lower core material 214a beneath a top surface of the dielectric lining 306b. In some embodiments, the etchant 1404 may contain nitric acid, hydrofluoric acid, and / or the like.

[0085] As shown in cross-sectional view 1500 of Fig. As shown in Figure 15, a weighted core material layer 1502 is formed on the uppermost surface of the lower core material 214a and within the multiple trenches 1202. The weighted core material layer 1502 can contain a metal or a metal alloy. For example, the weighted core material layer 1502 can contain iron, cobalt, nickel, tungsten, copper, aluminum, gold, silver, and / or the like. The weighted core material layer 1502 can be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, sputtering, or the like) and / or a plating process (e.g., electroplating, electroless plating, etc.).

[0086] As shown in cross-sectional view 1600 of Fig. Figure 16 shows the weighted core material layer (e.g., 1502 of Fig. 15) recessed to form a weighted core material 216 located at a non-zero distance below a top surface of the dielectric lining 306b. In some embodiments, the weighted core material 216 may also be recessed below a top surface of the second semiconductor body 304. In some embodiments, the weighted core material layer may be recessed by exposing the weighted core material layer to an etchant 1602 having high etch selectivity. The high etch selectivity etches the weighted core material layer without significantly etching the dielectric lining 306b, thus recessing the weighted core material 216 below the dielectric lining 306b. In some embodiments, the etchant 1602 may contain nitric acid, hydrochloric acid, and / or the like.

[0087] As shown in cross-sectional view 1700 of Fig. As shown in Figure 17, an upper core material layer 1702 is formed on a top surface of the weighted core material 216. In some embodiments, the upper core material layer 1702 may contain a semiconductor material, such as polysilicon or the like. In some embodiments, the upper core material layer 1702 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, sputtering, or the like) on the top surface of the weighted core material 216 and within the multiple grooves 1202. In some embodiments, the upper core material layer 1702 may be formed such that it extends continuously from above the second semiconductor body 304 to opposite outermost sidewalls of the first semiconductor body 302 and the second semiconductor body 304.

[0088] As shown in cross-sectional view 1800 of Fig. As shown in Figure 18, the upper core material layer (e.g., 1702 of Fig. 17) recessed to form an upper core material 214b, which is confined within the multiple trenches 1202, and to form a peripheral core material 312 along opposite sides of the first semiconductor body 302 and the second semiconductor body 304. In some embodiments, the upper core material 214b may be recessed below a top surface of the second semiconductor body 304. In some embodiments, the upper core material layer may be recessed by exposing the upper core material layer to an etchant (not shown) having high etch selectivity. The high etch selectivity etches the upper core material layer without significantly etching the dielectric lining 306b, thus recessing the upper core material layer below the dielectric lining 306b.

[0089] After forming the upper core material 214b, a second dielectric layer 306c is formed over the dielectric lining 306b and the upper core material 214b. In some embodiments, the second dielectric layer 306c can be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like).

[0090] As shown in the cross-sectional view from 1900. Fig. As shown in 19, part of the dielectric lining (e.g. 306b of Fig. 18) and part of the second dielectric layer (e.g. 306c of Fig. 18) from within the comb region 202 to form an opening 1902 that exposes the second semiconductor body 304. The opening 1902 is formed by side walls of a dielectric structure 306 and forms several comb fingers 104. The several comb fingers 104 each have a dielectric covering 218 that extends continuously around the core material 214 and the weighted core material 216. In some embodiments, the core material 214 covers the uppermost and lowermost surfaces of the weighted core material 216. In some embodiments, the dielectric lining (306b of Fig. 18) and the second dielectric layer (e.g. 306c of Fig. 18) selectively exposed to an etching agent 1904 in accordance with a mask 1906.

[0091] As shown in cross-sectional view 2000 from Fig. As shown in Figure 20, a first semiconductor layer 2002 is formed within the opening 1902, above the dielectric structure 306 and along opposite outermost sidewalls of the dielectric structure 306. In some embodiments, the first semiconductor layer 2002 may contain a semiconductor material, such as polysilicon. In some embodiments, the first semiconductor layer 2002 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like).

[0092] After the formation of the first semiconductor layer 2002, an additional dielectric layer 2004 is formed over the first semiconductor layer 2002 and along opposite outermost sidewalls of the first semiconductor layer 2002. In some embodiments, the additional dielectric layer 2004 can be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like). In some embodiments, the additional dielectric layer 2004 is formed to cover the first semiconductor layer 2002 and is subsequently patterned to remove a portion of the additional dielectric layer 2004 from within the ridge region 202 and the bar region 208. After patterning, the additional dielectric layer 2004 remains along the sidewalls of the first semiconductor layer 2002 and over the first semiconductor layer 2002 within the frame region 210.In some embodiments, the additional dielectric layer 2004 can be removed from within the comb region 202 and the bar region 208 by selectively exposing the additional dielectric layer 2004 to an etching agent (not shown) in accordance with a mask formed over the additional dielectric layer 2004.

[0093] As shown in cross-sectional view 2100 of Fig. As shown in Figure 21, a second semiconductor layer 2102 is formed over the first semiconductor layer 2002, over the additional dielectric layer 2004, and along opposite outermost sidewalls of the additional dielectric layer 2004. In some embodiments, the second semiconductor layer 2102 may contain a semiconductor material, such as polysilicon. In some embodiments, the second semiconductor layer 2102 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like).

[0094] As shown in cross-sectional view 2200 of Fig. As shown in Figure 22, the first semiconductor layer 2002 and the second semiconductor layer 2102 are selectively structured to form multiple sacrificial segments 2202 within the comb region 202. The multiple sacrificial segments 2202 can include segments bounded between adjacent of the multiple comb fingers 104 and / or segments that bridge one or more of the multiple comb fingers 104. Selective structuring of the first semiconductor layer 2002 also forms an upper semiconductor layer 320 above the second semiconductor body 304 and a peripheral first semiconductor layer 314 along opposite outermost sidewalls of the dielectric structure 306. In some embodiments, the additional dielectric layer 2004 can also be selectively structured.Selective structuring of the additional dielectric layer 2004 forms a first additional dielectric 318a over the second semiconductor body 304 and a second additional dielectric 318b along opposite outermost side walls of the peripheral first semiconductor layer 314.

[0095] As shown in cross-sectional view 2300 of Fig. As shown in Figure 23, a conductive layer 2302 is formed over the second semiconductor body 304. The conductive layer 2302 extends continuously over the comb region 202, the bar region 208, and the frame region 210. In some embodiments, the conductive layer 2302 may contain a metal such as aluminum, tungsten, copper, and / or the like. In some embodiments, the conductive layer 2302 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, an ALD process, or the like) and / or an electroplating process.

[0096] As shown in cross-sectional view 2400 of Fig. As shown in Figure 24, the conductive layer 2302 is structured to form a conductive cap 224 within the comb region 202 and further to form one or more conductive connectors 228 within the frame region 210. The conductive cap 224 is vertically separated from one or more of the multiple comb fingers 104 by the multiple sacrificial segments 2202. The one or more conductive connectors 228 extend continuously from directly above the dielectric structure 306 to directly above the first additional dielectric 318a.

[0097] As shown in cross-sectional view 2500 of Fig. As shown in Figure 25, the dielectric structure 306 is selectively structured to expose parts of the second semiconductor body 304. In some embodiments, the dielectric structure 306 can be selectively structured to expose the first side 304a of the second semiconductor body 304 within the comb region 202 and within the bar region 208.

[0098] As shown in cross-sectional view 2600 of Fig. As shown in Figure 26, an additional dielectric material can be formed and then structured to create a third additional dielectric 318c and an upper dielectric 322 over the conductive cap 224 and the one or more conductive connectors 228. The substrate 213 is subsequently etched to remove portions of the second semiconductor body 304 within the comb region 202, the bar region 208, and the frame region 210. Removing portions of the second semiconductor body 304 exposes the multiple comb fingers 104 and a bar 208c, allowing the multiple comb fingers 104 and the bar 208c to move during operation of the MEMS structure. In some embodiments (not shown), after the second semiconductor body 304 has been etched, the first semiconductor body 302 can be removed and the second semiconductor body 304 can be attached to a base substrate (as e.g. in Fig. 4C shown).

[0099] In some embodiments, the second semiconductor body 304 can be etched by exposing it to a wet etching agent 2602. In some embodiments, the multiple cavities 308 can influence the etching rate of the wet etching agent 2602 to selectively remove parts of the second semiconductor body 304 while leaving other parts intact. In some embodiments, the wet etching agent 2602 can contain hydrofluoric acid (HF), potassium hydroxide (KOH), sodium hydroxide (NaOH), nitric acid (HNO3), a wet etching agent containing chlorine, a wet etching agent containing fluorine, a wet etching agent containing both chlorine and fluorine, and / or the like.

[0100] Fig. Figures 27-44 illustrate cross-sectional views of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Although the cross-sectional views 2700-4400, which are in Fig. As shown in 27-44, and described in relation to a procedure, it is clear that the structures shown in Fig. 27-44 are shown, are not limited to the process of formation, but are rather independent, separate from the process.

[0101] As shown in cross-sectional view 2700 of Fig. As shown in Figure 27, a first semiconductor body 302 is provided. The first semiconductor body 302 has a first side 302a and a second side 302b, which is opposite the first side 302a. The first semiconductor body 302 also has a comb region 202, a bar region 208, and a frame region 210.

[0102] As shown in cross-sectional view 2800 of Fig. As shown in Figure 28, several cavities 308 are formed within the first side 302a of the first semiconductor body 302. The multiple cavities 308 are formed by side walls and a recessed surface of the first semiconductor body 302.

[0103] As shown in cross-sectional view 2900 of Fig. As shown in Figure 29, the first semiconductor body 302 is bonded to a second semiconductor body 304 to form a substrate 213. In some embodiments, a first dielectric layer 306a is formed along the first side 302a of the first semiconductor body 302. The first semiconductor body 302 is then bonded by the first dielectric layer 306a to a second side 304b of the second semiconductor body 304.

[0104] As shown in cross-sectional view 3000 of Fig. As shown in Figure 30, several grooves 1202 are formed along the first side 304a of the second semiconductor body 304. The several grooves 1202 are formed by side walls and a recessed surface of the second semiconductor body 304. In some embodiments, the several grooves 1202 can be formed by selectively exposing the first side 304a of the second semiconductor body 304 to an etching agent 1204 in accordance with a mask 1206.

[0105] As shown in cross-sectional view 3100 of Fig. As shown in Figure 31, a dielectric lining 306b is formed along the inner surfaces of the second semiconductor body 304, which form the multiple grooves 1202. In some embodiments, the dielectric lining 306b is formed such that it extends continuously from within the multiple grooves 1202 to opposite outermost side walls of the first semiconductor body 302, the first dielectric layer 306a, and the second semiconductor body 304.

[0106] A lower core material 214a is subsequently formed on the dielectric lining 306b and within the multiple trenches 1202. In some embodiments, the lower core material 214a can be formed above a top surface of the dielectric lining 306b and subsequently recessed to form the lower core material 214a such that it has a top surface that lies below a top surface of the dielectric lining 306b at a non-zero distance.

[0107] As shown in cross-sectional view 3200 of Fig. As shown in Figure 32, the lower core material 214a is selectively structured to form cavities 3202 within corresponding to the multiple trenches 1202. The cavities 3202 are formed by sidewalls and a recessed surface of the lower core material 214a. In some embodiments, the cavities 3202 can be formed using a self-aligning mask extending along sidewalls of the dielectric lining 306b, while horizontally extending surfaces of the lower core material 214a are exposed.

[0108] As shown in cross-sectional view 3300 of Fig. As shown in Figure 33, a weighted core material layer 1502 is formed on a top surface of the lower core material 214a and within the cavities 3202 in the lower core material 214a. In some embodiments, the weighted core material layer 1502 can be formed such that it extends continuously from within the cavities 3202 in the lower core material 214a to a top surface of the dielectric lining 306b.

[0109] As shown in cross-sectional view 3400 of Fig. As shown in Figure 34, the weighted core material layer (e.g., 1502 of Fig. 15) deepened to form a weighted core material 216, which is confined within the cavities 3202 within the lower core material 214a. In some embodiments, the weighted core material layer can be deepened by exposing the weighted core material layer to an etchant 1602 having high etch selectivity.

[0110] As shown in cross-sectional view 3500 of Fig. As shown in Figure 35, an upper core material layer 1702 is formed on the uppermost surfaces of both the lower core material 214a and the weighted core material 216. In some embodiments, the upper core material layer 1702 can contain a semiconductor material, such as polysilicon or the like. In some embodiments, the upper core material layer 1702 can contain the same material as the lower core material 214a. In other embodiments, the upper core material layer 1702 and the lower core material 214a can contain different materials.

[0111] As shown in cross-sectional view 3600 of Fig. As shown in Figure 36, the upper core material layer (e.g., 1702 of Fig. 17) recessed to form an upper core material 214b, which is confined within the multiple trenches 1202, and to form a peripheral core material 312 along opposite sides of the first semiconductor body 302 and the second semiconductor body 304. In some embodiments, the upper core material 214b may be recessed below a top surface of the second semiconductor body 304. After the upper core material 214b is formed, a second dielectric layer 306c is formed over the dielectric lining 306b and the upper core material 214b.

[0112] As shown in cross-sectional view 3700 of Fig. As shown in 37, part of the dielectric lining (e.g. 306b of Fig. 36) and part of the second dielectric layer (e.g. 306c of Fig. 36) from within the comb region 202 to form an opening 1902 that exposes the second semiconductor body 304. The opening 1902 is formed by side walls of a dielectric structure 306 and forms several comb fingers 104. The several comb fingers 104 each have a dielectric covering 218 that extends continuously around the core material 214 and the weighted core material 216. In some embodiments, the dielectric lining (306b of Fig. 36) and the second dielectric layer (e.g. 306c of Fig. 36) selectively exposed to an etching agent 1904 in accordance with a mask 1906.

[0113] As shown in cross-sectional view 3800 of Fig. As shown in Figure 38, a first semiconductor layer 2002 is formed within the opening 1902, above the dielectric structure 306 and along opposite outermost side walls of the dielectric structure 306.

[0114] After the formation of the first semiconductor layer 2002, an additional dielectric layer 2004 is formed over the first semiconductor layer 2002 and along opposite outermost sidewalls of the first semiconductor layer 2002. In some embodiments, the additional dielectric layer 2004 is formed to cover the first semiconductor layer 2002 and is subsequently patterned to remove the additional dielectric layer 2004 from within the comb region 202 and the bar region 208. After patterning, the additional dielectric layer 2004 remains along the sidewalls of the first semiconductor layer 2002 and over the first semiconductor layer 2002 within the frame region 210.In some embodiments, the additional dielectric layer 2004 can be removed from within the comb region 202 and the bar region 208 by selectively exposing the additional dielectric layer 2004 to an etching agent in accordance with a mask formed over the additional dielectric layer 2004.

[0115] As shown in cross-sectional view 3900 of Fig. As shown in Figure 39, a second semiconductor layer 2102 is formed over the first semiconductor layer 2002, over the additional dielectric layer 2004, and along opposite outermost side walls of the additional dielectric layer 2004.

[0116] As shown in cross-sectional view 4000 of Fig. As shown in Figure 40, the first semiconductor layer 2002 and the second semiconductor layer 2102 are selectively structured to form multiple sacrificial segments 2202 within the comb region 202. The multiple sacrificial segments 2202 can include segments located between adjacent of the multiple comb fingers 104 and / or segments that bridge one or more of the multiple comb fingers 104. Selective structuring of the first semiconductor layer 2002 also forms an upper semiconductor layer 320 above the second semiconductor body 304 and a peripheral first semiconductor layer 314 along opposite outermost sidewalls of the dielectric structure 306. In some embodiments, the additional dielectric layer 2004 can also be selectively structured.Selective structuring of the additional dielectric layer 2004 forms a first additional dielectric 318a over the second semiconductor body 304 and a second additional dielectric 318b along opposite outermost side walls of the peripheral first semiconductor layer 314.

[0117] As shown in cross-sectional view 4100 of Fig. As shown in Figure 41, a conductive layer 2302 is formed over the second semiconductor body 304. The conductive layer 2302 extends continuously over the comb region 202, the bar region 208, and the frame region 210.

[0118] As shown in cross-sectional view 4200 of Fig. As shown in Figure 42, the conductive layer 2302 is structured to form a conductive cap 224 within the comb region 202 and further to form one or more conductive connectors 228 within the frame region 210. The conductive cap 224 is vertically separated from one or more of the multiple comb fingers 104 by the multiple sacrificial segments 2202. The one or more conductive connectors 228 extend continuously from directly above the dielectric structure 306 to directly above the first additional dielectric 318a.

[0119] As shown in cross-sectional view 4300 of Fig. As shown in Figure 43, the dielectric structure 306 is selectively structured to expose parts of the second semiconductor body 304. In some embodiments, the dielectric structure 306 can be selectively structured to expose the first side 304a of the second semiconductor body 304 within the comb region 202 and within the bar region 208.

[0120] As shown in cross-sectional view 4400 of Fig. As shown in Figure 44, an additional dielectric material can be formed and then structured to form a third additional dielectric 318c and an upper dielectric 322 over the conductive cap 224 and the one or more conductive connectors 228.

[0121] The substrate 213 is subsequently etched to remove portions of the second semiconductor body 304 within the comb region 202, the bar region 208, and the frame region 210. Removing portions of the second semiconductor body 304 exposes the multiple comb fingers 104 and a bar 208c, allowing the multiple comb fingers 104 and the bar 208c to move during operation of the MEMS structure. In some embodiments (not shown), after the second semiconductor body 304 has been etched, the first semiconductor body 302 can be removed, and the second semiconductor body 304 can be attached to a base substrate (such as in Fig. 4C) are attached.

[0122] Fig. Figures 45-60 illustrate cross-sectional views of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb. Although the cross-sectional views 4500-6000, which are in Fig. As shown in 45-60, and described in relation to a procedure, it is clear that the structures shown in Fig. 45-60 are shown, are not limited to the process of formation, but are rather independent, separate from the process.

[0123] As shown in cross-sectional view 4500 of Fig. As shown in Figure 45, a first semiconductor body 302 is provided. The first semiconductor body 302 has a first side 302a and a second side 302b, which is opposite the first side 302a. The first semiconductor body 302 also has a comb region 202, a bar region 208, and a frame region 210.

[0124] As shown in cross-sectional view 4600 of Fig. As shown in Figure 46, several cavities 308 are formed within the first side 302a of the first semiconductor body 302. The multiple cavities 308 are formed by side walls and a recessed surface of the first semiconductor body 302.

[0125] As shown in cross-sectional view 4700 of Fig. As shown in Figure 47, the first semiconductor body 302 is bonded to a second semiconductor body 304 to form a substrate 213. In some embodiments, a first dielectric layer 306a is formed along the first side 302a of the first semiconductor body 302. The first semiconductor body 302 is then bonded by the first dielectric layer 306a to a second side 304b of the second semiconductor body 304.

[0126] As shown in cross-sectional view 4800 of Fig. As shown in Figure 48, several grooves 1202 are formed along a first side 304a of the second semiconductor body 304. The several grooves 1202 are formed by side walls and a recessed surface of the second semiconductor body 304. In some embodiments, the several grooves 1202 can be formed by selectively exposing the first side 304a of the second semiconductor body 304 to an etching agent 1204 in accordance with a mask 1206.

[0127] As shown in cross-sectional view 4900 of Fig. As shown in Figure 49, a dielectric lining 306b is formed along the inner surfaces of the second semiconductor body 304, which form the multiple trenches 1202. In some embodiments, the dielectric lining 306b is formed such that it extends continuously from within the multiple trenches 1202 to opposite outermost side walls of the first semiconductor body 302, the first dielectric layer 306a, and the second semiconductor body 304. A lower core material layer is subsequently formed on the dielectric lining 306b. The lower core material layer can be formed above a top surface of the dielectric lining 306b and subsequently recessed to form a core material 214 that lies at a non-zero distance below a top surface of the dielectric lining 306b.

[0128] As shown in cross-sectional view 5000 of Fig. As shown in Figure 50, a weighted core material layer is formed on a top surface of the core material 214 and within the multiple trenches 1202. In some embodiments, the weighted core material layer can be formed such that it extends continuously from within the multiple trenches 1202 to a top surface of the dielectric lining 306b. The weighted core material layer is then recessed to form a weighted core material 216 that is confined within the multiple trenches 1202.

[0129] As shown in cross-sectional view 5100 of Fig. As shown in Figure 51, an upper core material layer 1702 is formed on the uppermost surfaces of the weighted core material 216. In some embodiments, the upper core material layer 1702 extends continuously from over the uppermost surfaces of the weighted core material 216 to opposite outermost side walls of the dielectric lining 306b.

[0130] As shown in cross-sectional view 5200 of Fig. As shown in Figure 52, parts of the upper core material layer (e.g., Figure 1702 of Figure 52) are Fig. 51) from directly above the second semiconductor body 304, leaving a peripheral core material 312 along opposite sides of the first semiconductor body 302 and the second semiconductor body 304. After removal of the portions of the upper core material layer, a second dielectric layer 306c is formed over the dielectric lining 306b and the weighted core material 216.

[0131] As shown in cross-sectional view 5300 of Fig. As shown in section 53, part of the dielectric lining (e.g., 306b of Fig. 52) and part of the second dielectric layer (e.g. 306c of Fig. 52) from within the comb region 202 to form an opening 1902 that exposes the second semiconductor body 304. The opening 1902 is formed by side walls of a dielectric structure 306 and forms several comb fingers 104. The several comb fingers 104 each have a dielectric covering 218 that extends continuously around the core material 214 and the weighted core material 216. In some embodiments, the dielectric lining (306b of Fig. 52) and the second dielectric layer (e.g. 306c of Fig. 52) selectively exposed to an etching agent 1904 in accordance with a mask 1906.

[0132] As shown in cross-sectional view 5400 of Fig. As shown in Figure 54, a first semiconductor layer 2002 is formed within the opening 1902, over the dielectric structure 306, and along opposite outermost sidewalls of the dielectric structure 306. After the formation of the first semiconductor layer 2002, an additional dielectric layer 2004 is formed over the first semiconductor layer 2002 and along opposite outermost sidewalls of the first semiconductor layer 2002. In some embodiments, the additional dielectric layer 2004 is formed such that it covers the first semiconductor layer 2002 and is subsequently patterned to remove the additional dielectric layer 2004 from within the comb region 202 and the bar region 208. After patterning, the additional dielectric layer 2004 remains along the sidewalls of the first semiconductor layer 2002 and over the first semiconductor layer 2002 within the frame region 210.

[0133] As shown in cross-sectional view 5500 of Fig. As shown in Figure 55, a second semiconductor layer 2102 is formed over the first semiconductor layer 2002, over the additional dielectric layer 2004, and along opposite outermost side walls of the additional dielectric layer 2004.

[0134] As shown in cross-sectional view 5600 of Fig. As shown in Figure 56, the first semiconductor layer 2002 and the second semiconductor layer 2102 are selectively structured to form multiple sacrificial segments 2202 within the comb region 202. The multiple sacrificial segments 2202 can include segments bounded between adjacent of the multiple comb fingers 104 and / or segments that bridge one or more of the multiple comb fingers 104. Selective structuring of the first semiconductor layer 2002 also forms an upper semiconductor layer 320 above the second semiconductor body 304 and a peripheral first semiconductor layer 314 along opposite outermost sidewalls of the dielectric structure 306. In some embodiments, the additional dielectric layer 2004 can also be selectively structured.Selective structuring of the additional dielectric layer 2004 forms a first additional dielectric 318a over the second semiconductor body 304 and a second additional dielectric 318b along opposite outermost side walls of the peripheral first semiconductor layer 314.

[0135] As shown in cross-sectional view 5700 of Fig. As shown in Figure 57, a conductive layer 2302 is formed over the second semiconductor body 304. The conductive layer 2302 extends continuously over the comb region 202, the bar region 208, and the frame region 210.

[0136] As shown in cross-sectional view 5800 of Fig. As shown in Figure 58, the conductive layer 2302 is structured to form a conductive cap 224 within the comb region 202 and to further form one or more conductive connectors 228 within the frame region 210. The conductive cap 224 is vertically separated from one or more of the multiple comb fingers 104 by the multiple sacrificial segments 2202. The one or more conductive connectors 228 extend continuously from directly above the dielectric structure 306 to directly above the first additional dielectric 318a.

[0137] As shown in cross-sectional view 5900 of Fig. As shown in Figure 59, the dielectric structure 306 is selectively structured to expose parts of the second semiconductor body 304. In some embodiments, the dielectric structure 306 can be selectively structured to expose the first side 304a of the second semiconductor body 304 within the comb region 202 and within the bar region 208.

[0138] As shown in cross-sectional view 6000 of Fig. As shown in Figure 60, an additional dielectric material can be formed and then structured to form a third additional dielectric 318c and an upper dielectric 322 over the conductive cap 224 and the one or more conductive connectors 228.

[0139] The substrate 213 is then etched to remove portions of the second semiconductor body 304 within the comb region 202, the bar region 208, and the frame region 210. In some embodiments (not shown), after the second semiconductor body 304 has been etched, the first semiconductor body 302 can be removed, and the second semiconductor body 304 can be attached to a base substrate (as, for example, in Fig. 4C shown).

[0140] Fig. Figures 61-76 illustrate cross-sectional views of some embodiments of a method for forming a MEMS structure with a drive actuator for a weighted comb.

[0141] As shown in cross-sectional view 6100 of Fig. As shown in Figure 61, a first semiconductor body 302 is provided. The first semiconductor body 302 has a first side 302a and a second side 302b, which is opposite the first side 302a. The first semiconductor body 302 also has a comb region 202, a bar region 208, and a frame region 210.

[0142] As shown in cross-sectional view 6200 of Fig. As shown in Figure 62, several cavities 308 are formed within the first side 302a of the first semiconductor body 302. The multiple cavities 308 are formed by side walls and a recessed surface of the first semiconductor body 302.

[0143] As shown in cross-sectional view 6300 of Fig. As shown in Figure 63, the first semiconductor body 302 is bonded to a second semiconductor body 304 to form a substrate 213. In some embodiments, a first dielectric layer 306a is formed along the first side 302a of the first semiconductor body 302. The first semiconductor body 302 is then bonded by the first dielectric layer 306a to a second side 304b of the second semiconductor body 304.

[0144] As shown in cross-sectional view 6400 of Fig. As shown in Figure 64, several grooves 1202 are formed along a first side 304a of the second semiconductor body 304. The several grooves 1202 are formed by side walls and a recessed surface of the second semiconductor body 304. In some embodiments, the several grooves 1202 can be formed by selectively exposing the first side 304a of the second semiconductor body 304 to an etching agent 1204 in accordance with a mask 1206.

[0145] As shown in cross-sectional view 6500 of Fig. As shown in Figure 65, a dielectric lining 306b is formed along the inner surfaces of the second semiconductor body 304, which form the multiple grooves 1202. In some embodiments, the dielectric lining 306b is formed such that it extends continuously from within the multiple grooves 1202 to opposite outermost side walls of the first semiconductor body 302, the first dielectric layer 306a, and the second semiconductor body 304. A weighted core material layer is subsequently formed on the dielectric lining 306b. The weighted core material layer can be formed above a top surface of the dielectric lining 306b and subsequently recessed to form a weighted core material 216 that lies at a non-zero distance below a top surface of the dielectric lining 306b.

[0146] As shown in cross-sectional view 6600 of Fig. As shown in Figure 66, a lower core material layer is formed on a top surface of the weighted core material 216 and within the multiple trenches 1202. In some embodiments, the weighted core material layer can be formed such that it extends continuously from within the multiple trenches 1202 to over a top surface of the dielectric lining 306b. The lower core material layer is recessed to form a core material 214 that is confined within the multiple trenches 1202.

[0147] As shown in cross-sectional view 6700 of Fig. As shown in Figure 67, an upper core material layer 1702 is formed on the uppermost surfaces of the core material 214. In some embodiments, the upper core material layer 1702 extends continuously from over the uppermost surfaces of the core material 214 to along opposite outermost side walls of the dielectric lining 306b.

[0148] As shown in cross-sectional view 6800 of Fig. As shown in 68, parts of the upper core material layer (e.g. 1702 of Fig. 67) from directly above the second semiconductor body 304, leaving a peripheral core material 312 along opposite sides of the first semiconductor body 302 and the second semiconductor body 304. After removal of the portions of the upper core material layer, a second dielectric layer 306c is formed over the dielectric lining 306b and the core material 214.

[0149] As shown in cross-sectional view 6900 of Fig. As shown in 69, part of the dielectric lining (e.g. 306b of Fig. 68) and part of the second dielectric layer (e.g. 306c of Fig. 68) from within the comb region 202 to form an opening 1902 that exposes the second semiconductor body 304. The opening 1902 is formed by side walls of a dielectric structure 306 and forms several comb fingers 104. The several comb fingers 104 each have a dielectric covering 218 that extends continuously around the core material 214 and the weighted core material 216.

[0150] As shown in cross-sectional view 7000 of Fig. As shown in Figure 70, a first semiconductor layer 2002 is formed within the opening 1902, over the dielectric structure 306, and along opposite outermost sidewalls of the dielectric structure 306. After the formation of the first semiconductor layer 2002, an additional dielectric layer 2004 is formed over the first semiconductor layer 2002 and along opposite outermost sidewalls of the first semiconductor layer 2002. In some embodiments, the additional dielectric layer 2004 is formed such that it covers the first semiconductor layer 2002 and is subsequently patterned to remove the additional dielectric layer 2004 from within the comb region 202 and the bar region 208. After patterning, the additional dielectric layer 2004 remains along the sidewalls of the first semiconductor layer 2002 and over the first semiconductor layer 2002 within the frame region 210.

[0151] As shown in cross-sectional view 7100 of Fig. As shown in Figure 71, a second semiconductor layer 2102 is formed over the first semiconductor layer 2002, over the additional dielectric layer 2004 and along opposite outermost side walls of the additional dielectric layer 2004.

[0152] As shown in cross-sectional view 7200 of Fig. As shown in Figure 72, the first semiconductor layer 2002 and the second semiconductor layer 2102 are selectively structured to form multiple sacrificial segments 2202 within the comb region 202. The multiple sacrificial segments 2202 can include segments bounded between adjacent of the multiple comb fingers 104 and / or segments bridging one or more of the multiple comb fingers 104. Selective structuring of the first semiconductor layer 2002 also forms an upper semiconductor layer 320 above the second semiconductor body 304 and a peripheral first semiconductor layer 314 along opposite outermost sidewalls of the dielectric structure 306. In some embodiments, the additional dielectric layer 2004 can also be selectively structured.Selective structuring of the additional dielectric layer 2004 forms a first additional dielectric 318a over the second semiconductor body 304 and a second additional dielectric 318b along opposite outermost side walls of the peripheral first semiconductor layer 314.

[0153] As shown in cross-sectional view 7300 of Fig. As shown in Figure 73, a conductive layer 2302 is formed over the second semiconductor body 304. The conductive layer 2302 extends continuously over the comb region 202, the bar region 208, and the frame region 210.

[0154] As shown in cross-sectional view 7400 of Fig. As shown in Figure 74, the conductive layer 2302 is structured to form a conductive cap 224 within the comb region 202 and further to form one or more conductive connectors 228 within the frame region 210. The conductive cap 224 is vertically separated from one or more of the multiple comb fingers 104 by the multiple sacrificial segments 2202. The one or more conductive connectors 228 extend continuously from directly above the dielectric structure 306 to directly above the first additional dielectric 318a.

[0155] As shown in cross-sectional view 7500 of Fig. As shown in Figure 75, the dielectric structure 306 is selectively structured to expose parts of the second semiconductor body 304. In some embodiments, the dielectric structure 306 can be selectively structured to expose the first side 304a of the second semiconductor body 304 within the comb region 202 and within the bar region 208.

[0156] As shown in cross-sectional view 7600 of Fig. As shown in Figure 76, an additional dielectric material can be formed and then structured to form a third additional dielectric 318c and an upper dielectric 322 over the conductive cap 224 and the one or more conductive connectors 228.

[0157] The substrate 213 is then etched to remove portions of the second semiconductor body 304 within the comb region 202, the bar region 208, and the frame region 210. In some embodiments (not shown), after the second semiconductor body 304 has been etched, the first semiconductor body 302 can be removed, and the second semiconductor body 304 can be attached to a base substrate (as, for example, in Fig. 4C).

[0158] Fig. Figure 77 illustrates a flowchart of some embodiments of a method 7700 for forming an image sensor IC having a disclosed etched block structure.

[0159] While Procedure 7700 is illustrated and described here as a series of operations or events, it is clear that the illustrated sequence of such operations or events is not to be interpreted in a restrictive sense. For example, some operations may occur in different sequences and / or concurrently with other operations or events, apart from those illustrated and / or described here. Additionally, not all illustrated operations may be required to implement one or more aspects or embodiments of the present description. Furthermore, one or more of the operations shown here may be performed in one or more separate operations and / or phases.

[0160] In process 7702, several trenches are formed within a ridge area of ​​a substrate. In some embodiments, process 7702 can be carried out according to processes 7704-7708.

[0161] In process 7704, one or more cavities are formed within a first semiconductor body. Fig. Figure 10 illustrates a cross-sectional view of 1000 of some embodiments according to procedure 7704. Fig. Figure 28 illustrates a cross-sectional view 2800 of some additional embodiments according to process 7704. Fig. Figure 46 illustrates a cross-sectional view 4600 of some additional embodiments according to process 7704. Fig. Figure 62 illustrates a cross-sectional view 6200 of some additional embodiments according to process 7704.

[0162] In process 7706, the first semiconductor body is bonded to a second semiconductor body by a dielectric layer to form a substrate. Fig. Figure 11 illustrates a cross-sectional view 1100 of some embodiments according to process 7706. Fig. Figure 29 illustrates a cross-sectional view 2900 of some additional embodiments according to process 7706. Fig. Figure 47 illustrates a cross-sectional view 4700 of some additional embodiments according to process 7706. Fig. Figure 63 illustrates a cross-sectional view 6300 of some additional embodiments according to process 7706.

[0163] In process 7708, several trenches are formed within the second semiconductor body. Fig. Figure 12 illustrates a cross-sectional view of 1200 of some embodiments according to procedure 7708. Fig. Figure 30 illustrates a cross-sectional view of 3000 of some additional embodiments according to process 7708. Fig. Figure 48 illustrates a cross-sectional view 4800 of some additional embodiments according to process 7708. Fig. Figure 64 illustrates a cross-sectional view 6400 of some additional embodiments according to process 7708.

[0164] In process 7710, several comb fingers, each with a weighted core material, are formed within the multiple trenches. In some embodiments, process 7710 can be carried out according to processes 7712-7720.

[0165] In process 7712, a dielectric lining is formed along the inner surfaces of the second semiconductor body, forming the multiple trenches. Fig. Figure 13 illustrates a cross-sectional view 1300 of some embodiments according to procedure 7712. Fig. Figure 31 illustrates a cross-sectional view 3100 of some additional embodiments according to process 7712. Fig. Figure 49 illustrates a cross-sectional view 4900 of some additional embodiments according to process 7712. Fig. Figure 65 illustrates a cross-sectional view of 6500 of some additional embodiments according to procedure 7712.

[0166] In process 7714, a lower core material can be formed within the multiple trenches. Fig. Figures 13-14 illustrate cross-sectional views, and figures 1300 and 1400 illustrate some embodiments according to Procedure 7714. Fig. Figures 31-32 illustrate cross-sectional views, and figures 3100 and 3200 illustrate some additional embodiments according to Procedure 7714. Fig. Figure 49 illustrates a cross-sectional view 4900 of some additional embodiments according to process 7714.

[0167] In process 7716, a weighted core material is formed on the lower core material and / or within the multiple trenches. Fig. Figures 15-16 illustrate cross-sectional views, and figures 1500 and 1600 illustrate some embodiments according to Procedure 7716. Fig. Figures 33-34 illustrate cross-sectional views, and figures 3300 and 3400 illustrate some additional embodiments according to Procedure 7716. Fig. Figure 50 illustrates a cross-sectional view of 5000 of some additional embodiments according to process 7716. Fig. Figure 65 illustrates a cross-sectional view 6500 of some additional embodiments according to process 7716.

[0168] In process 7718, an upper core material can be formed on top of the weighted core material and within the multiple trenches. Fig. Figures 17-18 illustrate cross-sectional views, 1700 and 1800, of some embodiments according to Procedure 7718. Fig. Figures 35-36 illustrate cross-sectional views, and figures 3500 and 3600 illustrate some additional embodiments according to Procedure 7718. Fig. Figure 66 illustrates a cross-sectional view 6600 of some additional embodiments according to process 7718.

[0169] In process 7720, a second dielectric layer is applied along the top of the second semiconductor body to form multiple comb fingers within the comb area. Fig. Figures 18-19 illustrate cross-sectional views, 1800 and 1900, of some embodiments according to Procedure 7720. Fig. Figures 36-37 illustrate cross-sectional views, and figures 3600 and 3700 illustrate some additional embodiments according to procedure 7720. Fig. Figures 52-53 illustrate cross-sectional views, and figures 5200 and 5300 illustrate some additional embodiments according to Procedure 7720. Fig. Figures 68-69 illustrate cross-sectional views, and figures 6800 and 6900 illustrate some additional embodiments according to procedure 7720.

[0170] In process 7722, portions of the substrate are removed between several comb fingers. In some embodiments, process 7722 can be performed according to process 7724.

[0171] In process 7724, parts of the second semiconductor body are removed between several comb fingers. Fig. Figure 26 illustrates a cross-sectional view 2600 of some embodiments according to process 7724. Fig. Figure 44 illustrates a cross-sectional view 4400 of some additional embodiments according to process 7724. Fig. Figure 60 illustrates a cross-sectional view of 4800 of some additional embodiments according to process 7724. Fig. Figure 76 illustrates a cross-sectional view 6400 of some additional embodiments according to process 7724.

[0172] Therefore, in some embodiments, the present disclosure relates to a MEMS structure comprising a drive actuator for a weighted comb having multiple fingers containing a core material and a weighted core material.

[0173] In some embodiments, the present disclosure relates to a MEMS structure (microelectromechanical systems structure). The MEMS structure comprises a first comb structure with multiple first comb fingers extending outwards from a first limb; a second comb structure with multiple second comb fingers extending outwards from a second limb, the multiple first comb fingers being inserted laterally between the multiple second comb fingers; and the multiple first comb fingers each containing a weighted core material and one or more peripheral materials, the weighted core material having a higher density than the one or more peripheral materials.In some embodiments, the one or more peripheral materials include a core material arranged along both a horizontally extending surface and a vertically extending surface of the weighted core material. In some embodiments, the ratio of a cross-sectional area of ​​the one or more peripheral materials to a cross-sectional area of ​​the weighted core material within corresponding first comb fingers is in a range between approximately 1:2 and approximately 1:4. In some embodiments, the one or more peripheral materials include a core material wherein the core material and the weighted core material have maximum widths that are substantially equal.In some embodiments, the one or more peripheral materials include a core material, wherein the core material extends continuously in a closed loop around the weighted core material in a cross-sectional view. In some embodiments, the one or more peripheral materials include a core material and a dielectric cover that extends continuously in a closed loop around the weighted core material and the core material in a cross-sectional view. In some embodiments, the one or more peripheral materials include a semiconductor material and the weighted core material includes a metal. In some embodiments, the multiple first comb fingers each have a tapered width that decreases away from the first leg; and the weighted core material has a tapered width that decreases away from the first leg.In some embodiments, the multiple first comb fingers each have a width and are laterally spaced apart from one another by a first distance; and the ratio of the width to the first distance is less than or equal to approximately 2:1. In some embodiments, the first comb structure is part of an anchor having multiple first legs extending outwards from a central region of the anchor, the multiple first legs having the first leg; the second comb structure is part of a test mass having multiple second legs, the multiple second legs having the second leg; and one or more beams are coupled between the test mass and a frame, the frame surrounding the test mass.

[0174] In other embodiments, the present disclosure relates to a MEMS structure. The MEMS structure comprises a first comb structure with multiple first comb fingers arranged within a cavity in a substrate, the multiple first comb fingers being spaced apart from one another by the cavity; each of the multiple first comb fingers contains a core material, a weighted core material vertically contacting the core material, and a dielectric covering surrounding the core material and the weighted core material. In some embodiments, the weighted core material has a higher density than the core material. In some embodiments, the density ratio of the weighted core material to the density of the core material is greater than approximately 5:1. In some embodiments, the core material contains polysilicon and the weighted core material contains tungsten.In some embodiments, the MEMS structure further comprises a second comb structure with multiple second comb fingers arranged within the cavity, the multiple first comb fingers being inserted laterally between adjacent of the multiple second comb fingers. In some embodiments, the MEMS structure further comprises a base substrate, wherein the first comb structure is coupled to the base substrate by one or more first bonding structures located between an upper surface of the base substrate and a lower surface of the first comb structure; a central frame coupled to the second comb structure; and an outer frame coupled to the central frame by one or more conductive connectors and further coupled to the base substrate by one or more second bonding structures located between the upper surface of the base substrate and a lower surface of the outer frame.In some embodiments, the MEMS structure further features an image sensor IC coupled to an upper surface of the middle frame that points away from the base substrate.

[0175] In other embodiments, the present disclosure relates to a method. The method comprises forming several trenches within a comb region of a substrate; forming several comb fingers within the several trenches, wherein the several comb fingers each contain a core material and a weighted core material, the weighted core material having a higher density than the core material; and removing portions of the substrate between the several comb fingers. In some embodiments, the several comb fingers each have a dielectric covering surrounding the core material and the weighted core material. In some embodiments, the core material contains a semiconductor material and the weighted core material contains a metal.

[0176] The foregoing outlines features of some embodiments so that those skilled in the art will better understand the aspects of this disclosure. Those skilled in the art will appreciate that they can already use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or obtain the same advantages as the embodiments presented herein. Those skilled in the art should also recognize that such equivalent designs do not deviate from the nature and scope of this disclosure and that they can make various changes, substitutions, and modifications herein without deviating from the nature and scope of this disclosure. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 636,905

[0001]

Claims

[1] MEMS structure (microelectromechanical systems structure), comprising: a first comb structure having several first comb fingers extending outwards from a first limb; a second comb structure having several second comb fingers extending outwards from a second limb, with the several first comb fingers being inserted laterally between the several second comb fingers; and wherein the multiple first comb fingers each contain a weighted core material and one or more peripheral materials, wherein the weighted core material has a greater density than the one or more peripheral materials. [2] MEMS structure according to claim 1, wherein the one or more peripheral materials include a core material which is arranged along both a horizontally extending surface and a vertically extending surface of the weighted core material. [3] MEMS structure according to claim 1 or 2, wherein the ratio of a cross-sectional area of ​​one or more peripheral materials to a cross-sectional area of ​​the weighted core material within corresponding one of the several first comb fingers is in a range between approximately 1:2 and approximately 1:

4. [4] MEMS structure according to claim 1, wherein the one or more peripheral materials contain a core material, wherein the core material and the weighted core material have maximum widths that are substantially equal. [5] MEMS structure according to claim 1, wherein the one or more peripheral materials contain a core material, the core material extending continuously in a closed loop around the weighted core material in a cross-sectional view. [6] MEMS structure according to claim 1, wherein the one or more peripheral materials include: a core material; and a dielectric covering that extends continuously in a closed loop around the weighted core material and the core material in a cross-sectional view. [7] MEMS structure according to one of claims 1 to 6, wherein the one or more peripheral materials contain a semiconductor material and the weighted core material contains a metal. [8] MEMS structure according to one of claims 1 to 7, wherein the first several comb fingers each have a conically tapered width that decreases away from the first limb; and wherein the weighted core material has a conically tapered width that decreases away from the first leg. [9] MEMS structure according to one of claims 1 to 7, wherein the several first comb fingers each have a width and are spaced laterally apart from each other by a first distance; and where the ratio of the width to the first distance is less than or equal to approximately 2:

1. [10] MEMS structure according to any one of claims 1 to 9, wherein the first comb structure is part of an anchor having several first legs extending outwards from a central area of ​​the anchor, the several first legs having the first leg; wherein the second comb structure is part of a test mass having multiple second legs, wherein the multiple second legs have the second leg; and wherein one or more beams are coupled between the test mass and a frame, the frame surrounding the test mass. [11] MEMS structure, exhibiting: a first comb structure comprising several first comb fingers arranged within a cavity in a substrate, the several first comb fingers being spaced apart from each other by the cavity; where each of the first comb fingers exhibits: a core material; a weighted core material that touches the core material vertically; and a dielectric covering that surrounds the core material and the weighted core material. [12] MEMS structure according to claim 11, wherein the weighted core material has a greater density than the core material. [13] MEMS structure according to claim 11 or 12, wherein the ratio of the density of the weighted core material to the density of the core material is greater than approximately 5:

1. [14] MEMS structure according to one of claims 11 to 13, wherein the core material contains polysilicon and the weighted core material contains tungsten. [15] MEMS structure according to one of claims 11 to 14, further comprising: a second comb structure having several second comb fingers arranged within the cavity, with the several first comb fingers being inserted laterally between adjacent of the several second comb fingers. [16] MEMS structure according to claim 15, further comprising: a base substrate, wherein the first comb structure is coupled to the base substrate by one or more first bonding structures arranged between an upper surface of the base substrate and a lower surface of the first comb structure; a central frame coupled to the second comb structure; and an outer frame coupled to the middle frame by one or more conductive connectors and further coupled to the base substrate by one or more second bonding structures located between the upper surface of the base substrate and a lower surface of the outer frame. [17] MEMS structure according to claim 16, further comprising: an image sensor IC coupled to an upper surface of the midframe, pointing away from the base substrate. [18] Method for forming a MEMS structure, comprising: Forming multiple trenches within a ridge area of ​​a substrate; Forming multiple comb fingers within the multiple trenches, each of the multiple comb fingers containing a core material and a weighted core material, the weighted core material having a greater density than the core material; and Removing parts of the substrate between the multiple comb fingers. [19] Method according to claim 18, wherein the multiple comb fingers each have a dielectric covering surrounding the core material and the weighted core material. [20] Method according to claim 18 or 19, wherein the core material contains a semiconductor material and the weighted core material contains a metal.

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