Integrated chip structure and method of forming the same

Abstract

The present invention relates to an integrated chip structure including a MEMS actuator. The MEMS actuator includes an anchor having a first plurality of branches extending outward from a central region of the anchor. The first plurality of branches respectively include a first plurality of fingers. A mass is about the anchor and includes a second plurality of branches extending inward from an inner sidewall of the mass. As viewed in a top view, the second plurality of branches respectively include a second plurality of fingers interleaved with the first plurality of fingers. One or more curved cantilever arms are coupled between the mass and a frame that encloses the mass. As viewed in a top view, the one or more curved cantilever arms have a curved outer surface having one or more inflection points. Embodiments of the present invention also relate to methods of forming an integrated chip structure.

Description

Technical Field

[0001] Embodiments of the present invention relate to integrated chip structures and methods for forming the same. Background Technology

[0002] Microelectromechanical systems, or MEMS, are technologies that integrate miniaturized mechanical and electromechanical components onto an integrated chip. MEMS devices are typically manufactured using microfabrication techniques. In recent years, MEMS devices have found widespread applications. For example, MEMS devices are found in handheld devices (e.g., accelerometers, gyroscopes, digital compasses), pressure sensors (e.g., collision sensors), microfluidic components (e.g., valves, pumps), optical switches (e.g., mirrors), and more. Summary of the Invention

[0003] Embodiments of the present invention provide an integrated chip structure comprising: a microelectromechanical system actuator, including: an anchor including a first plurality of branches extending outwardly from a central region of the anchor, the first plurality of branches each including a first plurality of fingers; a mass block surrounding the anchor and including a second plurality of branches extending inwardly from an inner sidewall of the mass block, the second plurality of branches, as viewed in a top view, each including a second plurality of fingers intersecting the first plurality of fingers; one or more curved cantilever arms coupled between the mass block and a frame, the frame enclosing the mass block; and wherein, as viewed in the top view, the one or more curved cantilever arms include a curved outer surface having one or more inflection points.

[0004] Another embodiment of the present invention provides an integrated chip structure comprising: a microelectromechanical system actuator disposed above a substrate and including a frame coupled to a mass block via one or more curved cantilever arms; an image sensor integrated chip disposed on the microelectromechanical system actuator; and wherein, as viewed in a top view of the one or more curved cantilever arms, the one or more curved cantilever arms include a curved outer surface having a plurality of inflection points respectively arranged between the inflection points.

[0005] Another embodiment of the present invention provides a method for forming an integrated chip structure, comprising: providing a substrate having a lower semiconductor layer, the lower semiconductor layer being separated from the semiconductor layer by an insulating layer; patterning the semiconductor layer to form a plurality of curved trenches on opposite sides of a cantilever region, forming a first plurality of straight trenches on opposite sides of a mass block region, and forming a second straight trench between a frame region and the plurality of curved trenches, wherein the plurality of curved trenches are separated from the first plurality of straight trenches by a first sacrificial region of the semiconductor layer, and separated from the second straight trenches by a second sacrificial region of the semiconductor layer; filling the plurality of curved trenches, the first plurality of straight trenches, and the second straight trenches with one or more filler materials; and removing the first sacrificial region and the second sacrificial region to form one or more curved cantilever arms, the one or more curved cantilever arms being separated from the mass block and the frame by a non-zero spacing, wherein the one or more curved cantilever arms have curved sidewalls extending continuously between the mass block and the frame. Attached Figure Description

[0006] The various aspects of the invention can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industrial practice, the various components are not drawn to scale. In fact, for clarity of discussion, the dimensions of the various components may be arbitrarily increased or decreased.

[0007] Figures 1A to 1B Some embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0008] Figures 2A to 2B Additional embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0009] Figures 3A to 3B Some embodiments of the operation of an actuator having one or more curved cantilever arms within a disclosed integrated chip structure are shown.

[0010] Figures 4A to 4B Some embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0011] Figures 5A to 5C Some embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0012] Figure 6A top view is shown illustrating some embodiments of a disclosed bending cantilever for MEMS actuators.

[0013] Figure 7 Additional embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0014] Figures 8 to 17 Cross-sectional views are shown of some embodiments of a method for forming an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms.

[0015] Figure 18 Flowcharts of some embodiments of a method for forming an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown. Detailed Implementation

[0016] The following disclosure provides numerous different embodiments or instances for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the invention. Of course, these are merely examples and not intended to be limiting. For example, in the following description, forming a first component above or on a second component can include embodiments where the first and second components are in direct contact, and can also include embodiments where an additional component can be formed between the first and second components, such that the first and second components are not in direct contact. Furthermore, reference numerals and / or letters may be repeated in various examples. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the discussed embodiments and / or configurations.

[0017] Additionally, for ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper” may be used herein to describe the relationship between one element or component and another, as shown in the figures. Besides the orientations shown in the figures, spatial relative terms are intended to include different orientations of the device during use or operation. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein can be interpreted accordingly.

[0018] Many modern cameras include image stabilization technology. Image stabilization is a technique to reduce blur associated with movement of the imaging device during exposure (e.g., camera shake). Blur typically occurs when the image sensor moves during exposure. This movement causes light initially incident on one pixel to propagate to neighboring pixels, resulting in blur. As camera resolution increases, the size of the pixel area within the camera decreases, making blur caused by movement (e.g., camera shake) more noticeable in the captured image.

[0019] Optical image stabilization (OIS) is a form of image stabilization technique used to reduce blur caused by involuntary camera movement, such as camera shake. OIS senses camera movement and then compensates for it by controlling the optical path between the target and the image sensor. The optical path can be controlled by moving mechanical parts of the camera to ensure that light reaches the same pixels on the image sensor even if movement occurs.

[0020] Some cameras may include an OIS system with an image sensor integrated chip disposed on a MEMS actuator. The MEMS actuator is configured to move the image sensor integrated chip in a manner that compensates for camera movement. The MEMS actuator may include a frame coupled to a package. A mass block is coupled to the frame via one or more cantilever arms. The mass block is also coupled to the image sensor integrated chip and configured to move during operation to compensate for camera movement. It has been recognized that the stress on one or more cantilever arms can be significant during extreme camera movement. For example, when dropped from a height of approximately 1.5 meters, one or more cantilever arms may experience approximately 10 6 The stress is MPa (megapascals). Such high stress could damage one or more cantilever arms of a MEMS actuator, rendering the camera's OIS system inoperable.

[0021] This invention relates to an integrated chip structure including a MEMS (Micro-Electro-Mechanical System) actuator having a mass block coupled to a frame via one or more curved cantilever arms. In some embodiments, the MEMS actuator includes an anchor coupled to a substrate. The anchor includes a first plurality of branches, each having a first plurality of fingers. The mass block surrounds the anchor and includes a second plurality of branches, each having a second plurality of fingers, which, when viewed in a top view, interleave with the first plurality of fingers. One or more curved cantilever arms are coupled between the mass block and the frame, which encloses the mass block. The one or more curved cantilever arms include a curved outer surface, which, when viewed in a top view, has one or more inflection points. The curved outer surface of the one or more curved cantilever arms reduces stress on the one or more curved cantilever arms during extreme movement of the MEMS actuator. By reducing stress on the one or more curved cantilever arms during extreme movement, the disclosed MEMS actuator is able to provide improved reliability under real-world conditions, such as when dropped.

[0022] Figure 1A A top view 100 of some embodiments of a MEMS actuator 101 is shown, the MEMS actuator 101 having a mass block coupled to a frame via one or more curved cantilever arms.

[0023] MEMS actuator 101 includes a mass block 102 separated from a frame 104 by one or more first openings 105. One or more curved cantilever arms 106 pass through one or more first openings 105 to couple the mass block 102 to the frame 104. In some embodiments, the frame 104 encloses the mass block 102 in a first continuous loop (e.g., a first complete loop). The mass block 102 is also separated from an anchor 108 by one or more second openings 107. In some embodiments, the mass block 102 encloses the anchor 108 in a second continuous loop (e.g., a second complete loop). In some embodiments, MEMS actuator 101 includes an electrostatic actuator. In some embodiments, MEMS actuator 101 includes a comb actuator (e.g., an electrostatic comb actuator), such as a polysilicon levitating comb. In such embodiments, the anchor 108 has a first plurality of fingers interlaced with a second plurality of fingers of the mass block 102.

[0024] One or more curved cantilever arms 106 include a curved outer surface (e.g., a curved outer sidewall). In some embodiments, the curved outer surface may include a meandering shape as observed in a top view 100 of the MEMS actuator 101. In some embodiments, one or more curved cantilever arms 106 may include a plurality of inflection points separated by a plurality of inflection points. For example, one or more curved cantilever arms 106 may each include a first maximum inflection point (e.g., a local peak) on the side of the curved cantilever facing the mass block 102, a first minimum inflection point (e.g., a local valley) on the side of the curved cantilever facing the mass block 102, and an inflection point between the first maximum inflection point and the first minimum inflection point. In some embodiments, one or more curved cantilever arms may each include a plurality of maximum inflection points, a plurality of minimum inflection points, and a plurality of inflection points on opposite sides of the curved cantilever arms.

[0025] It has been recognized that curved outer surfaces (e.g., sidewalls) reduce localized stress on one or more curved cantilever arms 106 during movement of the MEMS actuator 101. For example, when falling from a height of approximately 1.5 meters, one or more curved cantilever arms 106 can withstand stresses at least two orders of magnitude smaller than those of a straight cantilever arm (e.g., approximately 10 meters). 4 The reliability of the MEMS actuator 101 can be improved by reducing the local stress on one or more bending cantilever 106 (MPa).

[0026] Figure 1B Cross-sectional views of some embodiments of an integrated chip structure 110 including a MEMS actuator 101 having a mass block 102 coupled to a frame 104 via one or more curved cantilever arms are shown. Figure 1A The top view of the MEMS actuator 101 shown can be viewed along... Figure 1B The section line A-A' is cut off.

[0027] The integrated chip structure 110 includes a semiconductor structure 112 disposed on the MEMS actuator 101. In various embodiments, the semiconductor structure 112 may include optical sensors (e.g., image sensor integrated chips), optical components (e.g., mirrors, lenses, etc.), sensors (e.g., for atomic force microscopes), RF (radio frequency) switches, etc.

[0028] In some embodiments, the semiconductor structure 112 is coupled to a mass block 102 of the MEMS actuator 101. In some embodiments, the frame 104 of the MEMS actuator is coupled to a housing 114 surrounding the MEMS actuator 101 and the semiconductor structure 112. During operation, the mass block 102 is configured to move in response to an applied signal to spatially move the semiconductor structure 112. In various embodiments, the mass block of the MEMS actuator 101 can move in a manner that changes the height and / or pitch (e.g., slope) of the semiconductor structure 112. The movement can be detected using a capacitive readout scheme.

[0029] Figure 2A Cross-sectional views of some additional embodiments of an integrated chip structure 200 including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0030] The integrated chip structure 200 includes a MEMS actuator 101 having a mass block 102 surrounded by a frame 104 and an anchor 108 surrounded by the mass block 102. An image sensor integrated chip 202 is disposed on the mass block 102. In some embodiments, the image sensor integrated chip 202 can be coupled to the mass block 102 via one or more first coupling elements 204. In some embodiments, the one or more first coupling elements 204 may include conductive structures (e.g., solder bumps, vertical line bonding, wire posts, etc.) and / or polymers. In some embodiments, the one or more first coupling elements 204 may include conductive structures (e.g., vertical line bonding) surrounded by a sealant (e.g., epoxy resin, epoxy resin with filler, epoxy acrylate, polymer, etc.).

[0031] The image sensor integrated chip 202 includes one or more pixel regions, each of which includes an image sensing element configured to convert electromagnetic radiation (e.g., visible light, ultraviolet radiation, etc.) into electrical signals. In some embodiments, the image sensor integrated chip 202 may include a CMOS (complementary metal-oxide) image sensor (CIS). In some embodiments, the image sensing element may include a photodiode, a photodetector, etc.

[0032] In some embodiments, the MEMS actuator 101 and the image sensor integrated chip 202 are disposed within a package 206 (e.g., a camera module). In such embodiments, the package 206 includes a housing 208 surrounding the MEMS actuator 101 and the image sensor integrated chip 202. In some embodiments, the housing 208 is attached to a substrate 210. In some embodiments, the substrate 210 may include a printed circuit board (PCB). A frame 104 of the MEMS actuator 101 is coupled to the housing 208 of the package 206. In some embodiments, the frame 104 is laterally and physically coupled to one or more sidewalls of the housing 208. The frame 104 is further coupled to a mass block 102 by one or more curved cantilever arms that provide support for the mass block 102 when the package 206 moves (e.g., when the package 206 is dropped), thereby protecting the mass block 102 from excessive and undesirable movement that could damage the mass block 102.

[0033] In various embodiments, the MEMS actuator 101 may be further coupled to the substrate 210 via one or more second coupling elements 212. In some embodiments, the anchor 108 of the MEMS actuator 101 may be attached to the substrate 210 via one or more second coupling elements 212. In some embodiments, the one or more second coupling elements 212 may include conductive structures (e.g., solder bumps, vertical line joints, wire posts, etc.) and / or polymers. In some embodiments, the one or more second coupling elements 212 may include conductive structures (e.g., vertical line joints) surrounded by a sealant (e.g., epoxy resin, epoxy resin with filler, epoxy acrylate, polymers, etc.). In some embodiments, the anchor 108 of the MEMS actuator 101 may be rigidly coupled to the substrate 210 via one or more second coupling elements 212. In some additional embodiments (not shown), one or more additional coupling elements (e.g., vertical line joints, wire joints, etc.) may be configured to electrically couple the mass block 102 and / or the image sensor integrated chip 202 to the substrate 210.

[0034] Optical system 214 is disposed along the upper surface of package 206 and above image sensor integrated chip 202. Optical system 214 includes one or more lenses and / or mirrors. During operation, optical system 214 is configured to focus incident radiation 216 onto one or more pixel areas of image sensor integrated chip 202.

[0035] Figure 2B It shows along Figure 2A Some embodiments of the MEMS actuator 101 are shown in top view 218 taken by cross section line A-A'.

[0036] As shown in top view 218, the mass block 102 of the MEMS actuator 101 is coupled to the frame 104 via one or more curved cantilever arms 106. In some embodiments, the mass block 102 has a maximum length 220 extending between its outermost edges. In some embodiments, the maximum length 220 of the mass block 102 is in the range of about 100 micrometers (μm) to about 2000 μm, about 200 μm to about 1200 μm, or other similar values. In some embodiments, the ratio of the maximum length 220 of the mass block 102 to the maximum length of the one or more curved cantilever arms 106 is between about 1 and about 4, between about 1.15 and about 3.2, or other similar values.

[0037] During operation, the packaging box (e.g., Figure 2A Undesired movement of the package 206 causes a shift in the focus of the optical system 214, resulting in incident radiation impacting different pixel regions within the image sensor integrated chip 202. The MEMS actuator 101 is configured to move the image sensor integrated chip 202 in response to the undesired movement of the package 206 to reduce the impact of the movement on the image sensor integrated chip 202 (e.g., reducing image blur by minimizing the movement of incident radiation between pixels) and thus stabilize the image captured by the image sensor integrated chip 202. For example, when a change in the position of the image sensor integrated chip 202 is detected, a signal is applied to the anchor 108 and / or mass block 102 of the MEMS actuator 101. This signal moves the mass block 102 and the image sensor integrated chip 202 to mitigate the effects of the movement (e.g., in a direction opposite to the direction of camera shake, thereby stabilizing the image captured by the image sensor integrated chip 202).

[0038] For example, Figures 3A to 3B Some embodiments are shown illustrating the operation of the disclosed MEMS actuator 101 having one or more curved cantilever arms.

[0039] like Figure 3AAs shown in cross-sectional view 300 and top view 302, at a first moment, the MEMS actuator 101 holds the image sensor integrated chip 202 at a first angle θ1 relative to the line 301, which is perpendicular to the upper surface of the substrate 210 (i.e., oriented at an angle Φ of 90 degrees relative to the upper surface of the substrate 210). The first angle θ1 is achieved by having a first distance d1 between staggered fingers in a first quadrant 304a surrounding the center of the anchor 108, a second distance d2 between staggered fingers in a second quadrant 304b surrounding the center of the anchor 108, a third distance d3 between staggered fingers in a third quadrant 304c surrounding the center of the anchor 108, and a fourth distance d4 between staggered fingers in a fourth quadrant 304d surrounding the center of the anchor 108. In some embodiments, the first angle θ1 may be approximately 90 degrees. In such embodiments, the plurality of outer edges of the mass block 102 are substantially the same distance above the substrate 210.

[0040] As the package 206 moves (e.g., due to hand tremors when a person holds the camera), the MEMS actuator 101 is configured to move the image sensor integrated chip 202 to compensate for this movement and thereby reduce blurring of the image captured by the image sensor integrated chip 202. For example, as Figure 3B As shown in cross-sectional view 306 and top view 308, at a second time, the MEMS actuator 101 can compensate for the movement of the package 206 by moving the image sensor integrated chip 202 to be oriented at a second angle θ2 relative to line 307 (perpendicular to the upper surface of the substrate 210). To move the image sensor integrated chip 202 to compensate for the movement, the distance between the staggered fingers in one or more quadrants 304a-304d is changed. For example, the distance between the staggered fingers in the second quadrant 304b can be changed from a second distance d2 to a modified second distance d2'. This change in the second distance alters the height of the first edge of the mass block 102, thereby causing the mass block 102 and the image sensor integrated chip 202 to rotate. In some embodiments, the distance between the staggered fingers can be changed by applying an electrical signal (e.g., voltage) to the anchor 108 and / or the mass block 102.

[0041] Figure 4A A top view of some additional embodiments of an integrated chip structure 400 including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms is shown.

[0042] The integrated chip structure 400 includes a MEMS actuator 101 having an anchor 108 surrounded by a mass block 102. The mass block 102 is further surrounded by a frame 104. The anchor 108 includes a cross shape having a first plurality of branches 108b extending outward from a central region 108c. In some embodiments, each of the first plurality of branches 108b includes a first segment 109a extending in a first direction and a second segment 109b extending in a second direction perpendicular to the first direction. In some embodiments, each of the first plurality of branches 108b includes a bend having a 90-degree angle. A first plurality of fingers 111 extend outward from each of the first plurality of branches 108b of the anchor 108.

[0043] In some embodiments, the width of the first segment 109a decreases as the distance from the central region 108c increases. For example, the width of the first segment 109a in one of the first plurality of branches 108b may decrease from a first width 402 near the central region 108c to a second width 404 at a greater distance from the central region 108c. In some embodiments, the width of the second segment 109b also decreases as the distance from the first segment 109a increases. For example, the width of the second segment 109b in one of the first plurality of branches 108b may decrease from a third width 406 near the first segment 109a to a fourth width 408 at a greater distance from the first segment 109a.

[0044] A mass block 102 surrounds an anchor 108. In some embodiments, the mass block 102 includes an annular region 102r that wraps around the anchor 108 in a closed loop (e.g., a complete loop). A second plurality of branches 102b extend inwardly from the inner sidewall of the annular region 102r of the mass block 102 facing the anchor 108. A second plurality of fingers 103 extend outwardly from each of the second plurality of branches 102b. A first plurality of fingers 111 intersect with the second plurality of fingers 103.

[0045] One or more curved cantilever arms 106 couple the mass block 102 to the frame 104. The one or more curved cantilever arms 106 include a curved outer surface having a plurality of inflection points 410. Figure 4A As viewed from a top view, in some embodiments, one or more curved cantilever 106 includes sidewalls having a plurality of inflection points 410. In some embodiments, one or more curved cantilever 106 extend laterally beyond the sidewalls of one or more of the second plurality of branches 102b.

[0046] In some embodiments, the mass block 102 may have four outer edges coupled to the four outer edges of the frame 104 by four curved cantilevered arms respectively disposed along one of the four outer edges of the mass block 102. In some such embodiments, the anchor 108 may include four branches extending outward from the central region 108c of the anchor 108, and the mass block 102 may include four branches extending inward from the annular region 102r. In some embodiments, as viewed in a top view, the anchor 108 includes a first branch extending rightward and outward from the central region 108c, a second branch extending leftward and outward from the central region 108c, a third branch extending downward and outward from the central region 108c, and a fourth branch extending upward and outward from the central region 108c. In some embodiments, the four branches are oriented at approximately 90 degrees to each other. In such embodiments, within the first quadrant 304a, second quadrant 304b, third quadrant 304c, and fourth quadrant 304d surrounding the central region 108c of the anchor 108, a first plurality of fingers 111 and a second plurality of fingers 103 are interleaved.

[0047] In some embodiments, one or more curved cantilever arms 106 extend from a surface of the mass block 102 facing a first direction to a surface of the frame 104 facing an opposite second direction. In some embodiments, one or more curved cantilever arms 106 may be coupled to the mass block 102 and the frame 104 via an absorber 412. The absorber 412 is configured to dampen vibrations on the one or more curved cantilever arms 106, thereby reducing stress on the one or more curved cantilever arms.

[0048] Figure 4B A top view 414 shows some embodiments of an absorber 412 coupled to one or more curved cantilever 106. As shown in top view 414, the absorber 412 may include a receiving element 416 coupled to one or more curved cantilever 106. The receiving element 416 is coupled to a damping element 420 via a resilient spring 418. During operation, the damping element 420 may move in response to stress caused by a resilient line 422 coupled to a base 424. The resilient spring 418 may move further in response to stress, thereby reducing stress on the ends of one or more curved cantilever 106.

[0049] Figure 5A A top view 500 of some additional embodiments of an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms is shown.

[0050] MEMS actuator 101 includes a mass block 102 coupled to frame 104 via one or more curved cantilever 106. Mass block 102 surrounds anchor 108. Mass block 102 has a first plurality of fingers, and anchor 108 includes a second plurality of fingers interleaved with the first plurality of fingers.

[0051] Mass block 102 includes a mass block central region 502a surrounded by an outer region of mass block, the outer region of mass block including a mass block core 506a and a mass block dielectric pad 504a. Frame 104 includes a frame central region 502b and one or more frame outer regions, the outer regions each including a frame core material 506b surrounded by a frame dielectric pad 504b. One or more curved cantilever arms 106 each include a cantilever central region 502c surrounded by an outer region of cantilever, the outer regions each including a cantilever core material 506c surrounded by a cantilever dielectric pad 504c. Anchor 108 includes an anchor central region 502d surrounded by an outer region of anchor, the outer regions each including an anchor core material 506d surrounded by an anchor dielectric pad 504d.

[0052] In some embodiments, the central regions 502a-502d may include a semiconductor material (e.g., silicon, polycrystalline silicon, crystalline silicon, doped silicon, etc.). In some embodiments, the dielectric pads 504a-504d may include oxides (e.g., silicon dioxide), nitrides (e.g., silicon nitride, silicon oxynitride, etc.), carbides (e.g., silicon carbide, silicon carbide, etc.). In some embodiments, the core material 506a-506d may include polycrystalline silicon. In some embodiments, the core material 506a-506d may extend to the uppermost surface of the dielectric pads 504a-504d and / or the central regions 502a-502d.

[0053] In some embodiments, the semiconductor material, core material, and dielectric pad may each have a Young's modulus greater than about 100 GPa, greater than about 120 GPa, greater than about 150 GPa, or other similar values. For example, in some embodiments, the dielectric pad may have a Young's modulus between about 150 GPa and about 200 GPa, the semiconductor material may have a Young's modulus between about 150 GPa and about 200 GPa, and the core material may have a Young's modulus between about 120 GPa and about 200 GPa. The relatively high Young's modulus of the semiconductor material, core material, and dielectric pad improves the ability of one or more bending cantilever 106 to withstand stress, thereby further improving the reliability of one or more bending cantilever 106.

[0054] Top view 508 shows an enlarged view of a portion of the MEMS actuator 101, further showing the mass block 102, one or more curved cantilever arms 106 and central regions 502a-502c within the frame 104, core material 506a-506c and dielectric pads 504a-504c.

[0055] Figure 5B It shows along Figure 5AA cross-sectional view 510 of the MEMS actuator 101 is taken by line 509. As shown in cross-sectional view 510, a frame 104, a mass block 102, one or more curved cantilever arms 106, and an anchor 108 are arranged within a semiconductor layer 512 (e.g., a MEMS substrate). Dielectric pads 504a-504d completely cover the sidewalls of the central regions 502a-502d and the core material 506a-506d.

[0056] One or more curved cantilever 106 are separated from frame 104 and mass block 102 by one or more first openings 105. Mass block 102 is further separated from anchor 108 by one or more second openings 107. One or more first openings 105 and one or more second openings 107 are respectively defined by the sidewalls of dielectric pads 504a-504d.

[0057] In some embodiments, a dielectric cap 514 may be disposed above the central regions 502a-502d, dielectric pads 504a-504d, and core material 506a-506d within the frame 104, the mass block 102, one or more curved cantilever arms 106, and the anchor 108. In some embodiments, the dielectric cap 514 may include oxides (e.g., silicon dioxide), nitrides (e.g., silicon nitride, silicon oxynitride, etc.), carbides (e.g., silicon carbide, silicon oxycarbide, etc.), etc. In such embodiments, the semiconductor layer 512, the dielectric pads 504a-504d, and the core material 506a-506d may extend continuously from the bottom surface of the MEMS actuator 101 to the dielectric cap 514. In other embodiments, the dielectric cap 514 may be omitted, such that the semiconductor layer 512, dielectric pads 504a-504d and core material 506a-506d extend continuously from the bottom surface of the MEMS actuator 101 to the top surface of the MEMS actuator 101.

[0058] Figure 5C It shows Figure 5A The image shows a three-dimensional view 516 of a portion 511 of the MEMS actuator 101. As shown in the three-dimensional view 516, the thickness 518 of one or more curved cantilever 106 may be approximately equal to the thickness of the mass block 102.

[0059] Figure 6 A top view showing some embodiments of the curved cantilever 600 is shown.

[0060] The curved cantilever 600 includes a wavy profile having opposite sides including curved segments. In some embodiments, the curved segments are separated by substantially straight regions. In other embodiments, the curved segments meet at a plurality of inflection points arranged along opposite sides of the curved cantilever. The length 602 of the curved cantilever 600 is in the range of about 200 micrometers (μm) to about 4000 μm, about 230 μm to about 3840 μm, or other similar values. In some embodiments, the curved cantilever 600 may have a wavelength 604 (e.g., the length between the peaks (maximum inflection points) and / or troughs (minimum inflection points) of the curved cantilever 600) in the range of about 100 μm to about 500 μm, about 200 μm to about 400 μm, or other similar values. In some embodiments, the curved cantilever 600 may have a wave height 606 (e.g., the height between the peak and the adjacent valley of the curved cantilever 600) in the range of about 5 μm and about 150 μm, about 10 μm and about 110 μm, or other similar values.

[0061] Due to the curvature of the curved cantilever 600, different locations on the curved cantilever 600 experience different amounts of stress during movement. For example, in some embodiments, the curvature of the curved cantilever 600 can induce a first stress 608 along the outer edge of the curved cantilever near the inflection point, which is greater than a second stress 610 along the outer edge of the curved cantilever (near the local maximum and / or minimum inflection points of the curved cantilever 600). In some embodiments, the curvature of the curved cantilever 600 can induce a third stress 612 in the central region of the curved cantilever 600 that is greater than the second stress 610. In some embodiments, the second stress 610 or the third stress 612 can be the maximum stress on the curved cantilever 600, which is less than about 2 × 10⁻⁶ in a drop test of 250 grams and 1.5 meters. 4 Megapascals (MPa), less than approximately 1.8 × 10⁻⁶ 4 MPa, approximately 1.743 x 10 4 MPa or other similar values, such as approximately 1.158 x 10 3 MPa. Because the maximum stress on the curved cantilever 600 is less than the maximum stress on the straight cantilever (e.g., less than about 1 x 10 MPa). 6 The bending cantilever 600 is less likely to break during periods of high stress (e.g., drop) on the bending cantilever 600, thus improving the reliability of the disclosed MEMS actuator.

[0062] Figure 7 Some additional embodiments of an integrated chip structure 700 including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms are shown.

[0063] The integrated chip structure 700 includes a package 206 (e.g., a camera module) disposed above a substrate 210. An optical system 214 is arranged along the upper surface of the package 206. In some embodiments, the optical system 214 may include an objective lens 214a and a floating lens 214b disposed between the objective lens 214a and the image sensor integrated chip 202. A MEMS actuator 101 is disposed within the package 206 below the optical system 214. The MEMS actuator 101 includes a frame 104 coupled to the sidewalls of the package 206. In some embodiments, a dielectric pad 504 disposed along the outermost sidewall of the MEMS actuator 101 may be coupled to the sidewalls of the package 206 (e.g., by an adhesive material). In other embodiments (not shown), a semiconductor material disposed along the outermost sidewall of the MEMS actuator 101 may be coupled to the sidewalls of the package 206.

[0064] An image sensor integrated chip 202 is disposed on the MEMS actuator 101 and located between the MEMS actuator 101 and the optical system 214. The image sensor integrated chip 202 includes an image sensing element 710 disposed within a substrate 702. In some embodiments, the image sensing element 710 may include a photodiode comprising a first region having a first doping type (e.g., n-type doping) and an adjacent second region having a second doping type different from the first doping type (e.g., p-type doping). A transistor gate structure 704 is disposed along a first side of the substrate 702. In some embodiments, the transistor gate structure 704 may correspond to a transfer transistor. In such an embodiment, the transistor gate structure 704 is laterally disposed between the image sensing element 710 and a floating diffusion well 712. The transistor gate structure 704 is configured to control charge transfer from the image sensing element 710 (e.g., the photodiode) to the floating diffusion well 712.

[0065] A dielectric structure 706 is disposed along a first side of the substrate 702. The dielectric structure 706 includes a plurality of stacked interlayer dielectric (ILD) layers. In some embodiments, a plurality of conductive interconnects 708 (e.g., conductive contacts, interconnects, and / or interconnect vias) are disposed within the dielectric structure 706.

[0066] A dielectric planarization structure 714 may be arranged along a second side of the substrate 702. The dielectric planarization structure 714 has a substantially flat surface facing away from the substrate 702. In various embodiments, the dielectric planarization structure 714 may include one or more stacked dielectric layers (e.g., oxides, nitrides, etc.). A grid structure 716 is disposed on the dielectric planarization structure 714. In various embodiments, the grid structure 716 may include a metal (e.g., aluminum, cobalt, copper, silver, gold, tungsten, etc.) and / or a dielectric material (e.g., SiO2, SiN, etc.). A color filter 718 is arranged within an opening in the grid structure 716. The color filter 718 is configured to selectively transmit incident radiation of a specific wavelength. For example, the color filter 718 may transmit radiation having wavelengths within a first range (e.g., corresponding to green light), while a second color filter (not shown) may transmit radiation having wavelengths within a second range different from the first range (e.g., corresponding to red light), etc. A microlens 720 is arranged above the color filter 718. The microlens 720 is laterally aligned with the color filter 718 and configured to focus incident radiation (e.g., light) onto the image sensing element 710.

[0067] In some embodiments, a MEMS gyroscope 722 and / or a MEMS accelerometer 724 may be disposed on a substrate 210. The MEMS gyroscope 722 and / or the MEMS accelerometer 724 are configured to detect and / or measure movement of the package 206. In some embodiments, the MEMS gyroscope 722 and / or the MEMS accelerometer 724 may be coupled to control circuitry 726 disposed on the substrate 210. The control circuitry 726 is configured to send a signal to a MEMS actuator 101 based on the detected movement sensed by the MEMS gyroscope 722 and / or the MEMS accelerometer 724. This signal is configured to cause the MEMS actuator 101 to move in a manner that mitigates the impact of the movement of the package 206 on the image sensor integrated chip 202, thereby reducing blurring of the image captured by the image sensor integrated chip 202.

[0068] Figures 8 to 17 Cross-sectional views 800-1700 illustrate some embodiments of a method for forming an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms. While the method is described... Figures 8 to 17 However, it should be understood that Figures 8 to 17 The structures disclosed herein are not limited to this method, but can exist independently of this method.

[0069] like Figure 8As shown in cross-sectional view 800 (taken along line 812) and top view 810 (taken along line 808), a substrate 802 is provided. The substrate 802 includes a lower semiconductor layer 804 separated from a semiconductor layer 512 by an insulating layer 806. In some embodiments, the lower semiconductor layer 804 and the semiconductor layer 512 may include silicon, germanium, gallium, etc. In some embodiments, the insulating layer 806 may include oxides (e.g., silicon oxide), nitrides (e.g., silicon oxynitride), etc.

[0070] In some embodiments, the lower semiconductor layer 804 may be a first substrate including a first semiconductor body, a processing wafer, etc. In some embodiments, the semiconductor layer 512 may be a second semiconductor body, a MEMS wafer, etc. In some embodiments, the substrate 802 may be provided by forming an insulating layer 806 over the lower semiconductor layer 804 and subsequently bonding the semiconductor layer 512 to the insulating layer 806. In some embodiments, the insulating layer 806 may be formed by a thermal oxidation process, such as a wet thermal oxidation process or a dry thermal oxidation process. In such embodiments, the lower semiconductor layer 804 is placed in a furnace and heated in the presence of oxygen to a temperature typically between about 800 degrees Celsius (°C) and about 1200 degrees Celsius to form the insulating layer 806. In other embodiments, the insulating layer 806 may be formed by a spin coating process, a plasma vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, an atomic layer deposition (ALD) process, or other techniques. In some embodiments, the semiconductor layer 512 is bonded to the top surface of the insulating layer 806 by a fusion bonding process.

[0071] like Figure 9 As shown in the cross-sectional view 900 (taken along line 812) and top view 928 (taken along line 808), the semiconductor layer 512 is patterned to form a plurality of trenches extending into the semiconductor layer 512 to define a cantilever region 902, a frame region 904, a mass block region 906, and an anchor region 908. The cantilever region 902, frame region 904, mass block region 906, and anchor region 908 are separated from each other by the plurality of trenches. In some embodiments, the cantilever region 902, frame region 904, mass block region 906, and anchor region 908 may also be separated from each other by sacrificial regions 910-914. The cantilever region 902 is defined by curved sidewalls of the semiconductor layer 512 that extend continuously between the frame region 904 and the mass block region 906.

[0072] In some embodiments, the plurality of trenches includes a plurality of curved trenches 916 located on opposite sides of the cantilever region 902, a first plurality of straight trenches 918 located on opposite sides of the mass block region 906, a second straight trench 920 located between the frame region 904 and the plurality of curved trenches 916, and a third straight trench 922 located between the anchor region 908 and the first plurality of straight trenches 918. The plurality of curved trenches 916 are separated from the first plurality of straight trenches 918 by a first sacrificial region 910 and from the second straight trench 920 by a second sacrificial region 912. The first plurality of straight trenches 918 are separated from the third straight trench 922 by a third sacrificial region 914. In some embodiments, the plurality of curved trenches 916, the first plurality of straight trenches 918, the second straight trench 920, and the third straight trench 922 have a bottom defined by a horizontally extending surface of the semiconductor layer 512.

[0073] In some embodiments, a plurality of curved trenches 916, a first plurality of straight trenches 918, a second straight trench 920, and a third straight trench 922 are defined by the sidewalls and horizontally extending surface of the semiconductor layer 512, respectively. In some embodiments, the plurality of curved trenches 916, the first plurality of straight trenches 918, the second straight trench 920, and the third straight trench 922 are formed by a photolithography process that forms a patterned mask layer 924 over the semiconductor layer 512, and subsequently by etching exposed areas of the semiconductor layer 512 with an etchant 926. In some embodiments, the etchant 926 may include a dry etchant. In some embodiments, the dry etchant may include a fluorine-based etching chemical. For example, the dry etchant may have etching chemicals including carbon tetrafluoride (CF4), trifluoromethane (CHF3), octafluorocyclobutane (C4F8), etc. In other embodiments, the dry etchant may include etching chemicals including chlorine (Cl2), HB4, argon (Ar), etc.

[0074] like Figure 10 As shown in cross-sectional view 1000 (taken along line 812) and top view 1004 (taken along line 808), one or more filler materials are formed within a plurality of trenches (e.g., a plurality of curved trenches 916, a first plurality of straight trenches 918, a second straight trench 920, and a third straight trench 922). The plurality of trenches are completely filled by one or more filler materials. In some embodiments, the one or more filler materials may include dielectric pads 504 formed along the inner surfaces of the plurality of trenches and core material 506 disposed on the dielectric pads 504. In some embodiments, the dielectric pads 504 may include oxides (e.g., silicon oxide), nitrides (e.g., silicon nitride), etc. In some embodiments, the core material 506 may include polycrystalline silicon, etc. In some embodiments, the one or more filler materials may include a Young's modulus greater than or equal to about 120 GPa.

[0075] In some embodiments, the dielectric pad 504 can be formed by a thermal oxidation process. In such embodiments, the semiconductor layer 512 can be exposed to high temperatures (e.g., greater than or equal to about 700°C, greater than or equal to about 800°C, between about 900°C and about 1100°C, or other similar values). In some embodiments, the semiconductor layer 512 can be exposed to high temperatures in the presence of water vapor. The thermal oxidation process forms oxides along the inner surfaces of a plurality of trenches. A core material 506 is then formed on the dielectric pad 504 and within the plurality of trenches by a deposition process. In various embodiments, the deposition process can include PVD, CVD, PE-CVD, ALD, etc. In some embodiments, a planarization process (e.g., chemical mechanical planarization (CMP)) can be performed along line 1002 to remove excess semiconductor material from above the top of the semiconductor layer 512.

[0076] like Figure 11 As shown in the cross-sectional view 1100 (taken along line 812) and top view 1102 (taken along line 808), a dielectric cap 514 is formed over the semiconductor layer 512. The dielectric cap 514 covers the cantilever region 902, the frame region 904, the mass block region 906, and the anchor region 908. The dielectric cap 514 exposes a first sacrificial region 910, a second sacrificial region 912, and a third sacrificial region 914. In various embodiments, the dielectric cap 514 includes oxides (e.g., silicon oxide), nitrides (e.g., silicon nitride, silicon oxynitride, etc.), carbides (e.g., silicon carbide, silicon oxycarbide, etc.), etc.

[0077] like Figure 12 As shown in the cross-sectional view 1200 (taken along line 812) and top view 1206 (taken along line 808), with the dielectric cap 514 positioned appropriately above the semiconductor layer 512, a release etching process is performed by exposing the semiconductor layer 512 to the etchant 1202. The release etching process removes the first sacrificial region (e.g., Figure 11 910) and the second sacrifice area (e.g., Figure 11 (912) to form one or more first openings 105, the first openings 105 separating one or more curved cantilever 106 from the frame 104 and the mass block 102 with a non-zero pitch. The release etching process also removes the third sacrificial region (e.g., Figure 11The process involves etching (914) to form one or more second openings 107 that separate the mass block 104 from the anchor 108. The release etching process also etches the semiconductor layer 512 beneath one or more first openings 105 and / or one or more second openings 107 to form a lower recess 1204 extending beneath portions of one or more curved cantilever 106, frame 104, mass block 102, and anchor 108. In some embodiments, the lower recess 1204 is disposed within the semiconductor layer 512 and extends beneath portions of the frame 104, mass block 102, one or more curved cantilever 106, and anchor 108. The lower recess 1204 communicates with one or more first openings 105 and one or more second openings 107.

[0078] In some embodiments, etchant 1202 is a wet etchant with high etch selectivity between semiconductor layer 512 and dielectric pad 504. The high etch selectivity allows etchant 1202 to etch semiconductor layer 512 at a first etch rate while simultaneously etching dielectric pad 504 at a second etch rate less than the first etch rate. In some embodiments, etchant 1202 may comprise hydrofluoric acid (HF) (e.g., aqueous HF etching or vapor HF etching). In other embodiments, etchant 1202 may comprise hydrogen peroxide (H2O2), potassium hydroxide (KOH), etc.

[0079] like Figure 13 As shown in cross-sectional view 1300 (taken along line 812) and top view 1302 (taken along line 808), the underlying semiconductor layer and insulating layer are removed from semiconductor layer 512 to form MEMS actuator 101. In some additional embodiments (not shown), dielectric cap 514 can be removed from semiconductor layer 512. In some embodiments, the underlying semiconductor layer, insulating layer, and / or dielectric cap 514 can be removed by etching processes, grinding processes, polishing processes (e.g., chemical mechanical planarization (CMP) processes), etc. In some embodiments, the underlying semiconductor layer, insulating layer, and / or dielectric cap 514 can be removed after attaching an image sensor integrated chip (e.g., shown in cross-sectional view 1400).

[0080] like Figure 14 As shown in the cross-sectional view 1400 (taken along line 1406) and top view 1404 (taken along line 1402), the image sensor integrated chip 202 is placed on the MEMS actuator 101. In some embodiments, the image sensor integrated chip 202 is coupled to the mass block 102 of the MEMS actuator 101 via one or more first coupling elements 204. In some embodiments, the one or more first coupling elements 204 may include conductive structures (e.g., solder bumps, vertical line joints, wire posts, etc.) and / or polymers. In some embodiments, the one or more first coupling elements 204 may be formed with a semiconductor layer (e.g., Figure 13 (512) direct contact.

[0081] like Figure 15 As shown in cross-sectional view 1500, the MEMS actuator 101 and the image sensor integrated chip 202 are housed within a package 206 (e.g., a camera module). The package 206 includes a housing 208 having sidewalls and a top surface surrounding the MEMS actuator 101 and the image sensor integrated chip 202. In some embodiments, the frame 104 of the MEMS actuator 101 is physically coupled to the sidewall of the package 206.

[0082] In some embodiments, the optical system 214 is positioned directly above the image sensor integrated chip 202 along the top of the package 206. The optical system 214 may include one or more lenses 214a-214b configured to focus incident radiation onto the image sensor integrated chip 202. In some embodiments (not shown), the MEMS actuator 101 and the image sensor integrated chip 202 may be placed within the package after the MEMS actuator 101 is coupled to the substrate.

[0083] like Figure 16 As shown in cross-sectional view 1600, the package 206 and / or MEMS actuator 101 are coupled to the substrate 210. In some embodiments, the substrate 210 may include a printed circuit board (PCB). In some embodiments, the MEMS actuator 101 may be coupled to the substrate 210 before the package 206 is formed over the MEMS actuator 101. In some embodiments, the MEMS actuator 101 may be coupled to the substrate 210 via one or more second coupling elements 212. In some embodiments, the one or more second coupling elements 212 may include conductive structures (e.g., solder bumps, vertical line joints, wire posts, etc.) and / or polymers. In some embodiments, the anchor 108 of the MEMS actuator 101 may be rigidly coupled to the substrate 210 via one or more second coupling elements 212.

[0084] like Figure 17As shown in cross-sectional view 1700, one or more additional integrated chip elements 722-726 are coupled to the substrate 210. In some embodiments, the one or more additional integrated chip elements 722-726 may include a MEMS gyroscope 722 and / or a MEMS accelerometer 724. The MEMS gyroscope 722 and / or the MEMS accelerometer 724 are configured to sense movement of the package 206 (e.g., during hand tremors). In some embodiments, the one or more additional integrated chip elements 722-726 may further and / or optionally include control circuitry 726 (e.g., a processor) configured to generate one or more signals in response to movement of the package 206 to control operation of the MEMS actuator 101. In various embodiments, the one or more additional integrated chip elements 722-726 may be coupled to the substrate 210 via a bonding process that forms one or more conductive bumps (e.g., solder bumps) between the one or more additional integrated chip elements 722-726 and the substrate 210.

[0085] Figure 18 A flowchart of some embodiments of a method 1800 for forming an integrated chip structure including a MEMS actuator having a mass block coupled to a frame via one or more curved cantilever arms is shown.

[0086] Although method 1800 is shown and described herein as a series of actions or events, it should be understood that the order in which these actions or events are shown should not be construed as limiting. For example, some actions may occur in a different order and / or simultaneously with other actions or events besides those shown and / or described herein. Furthermore, not all of the actions shown may be required to implement one or more aspects or embodiments described herein. Additionally, one or more actions described herein may be performed in one or more separate actions and / or phases.

[0087] At action 1802, a substrate having a semiconductor layer is provided, which is separated from the underlying semiconductor layer by an insulating layer. Figure 8 Cross-sectional view 800 and top view 810 are shown for some embodiments corresponding to action 1802.

[0088] At action 1804, multiple curved trenches are formed within the semiconductor layer to separate the cantilever region from the mass block region and the frame region. Figure 9 Cross-sectional view 900 and top view 928 are shown for some embodiments corresponding to action 1804.

[0089] At action 1806, multiple straight trenches are formed within the semiconductor layer and along the sides of the mass block region and the frame region. The multiple straight trenches are separated from multiple curved trenches by sacrificial regions. Figure 9Cross-sectional view 900 and top view 928 are shown for some embodiments corresponding to action 1806.

[0090] At action 1808, one or more filling materials are formed in multiple curved grooves and multiple straight grooves. Figure 10 Cross-sectional view 1000 and top view 1004 are shown for some embodiments corresponding to action 1808.

[0091] At action 1810, the semiconductor layer is patterned to remove one or more sacrificial regions and form a non-zero pitch that separates the cantilever from the mass block and frame. Figures 11 to 12 Cross-sectional views 1100 and 1200 and top views 1102 and 1206 are shown for some embodiments corresponding to action 1810.

[0092] At action 1812, the lower semiconductor layer and insulating layer are removed to define the MEMS actuator. Figure 13 Cross-sectional view 1300 and top view 1302 are shown for some embodiments corresponding to action 1812.

[0093] At action 1814, the side of the MEMS actuator is coupled to one or more sidewalls of the package. Figure 15 A cross-sectional view 1500 is shown, corresponding to some embodiments of action 1814.

[0094] Therefore, in some embodiments, the present invention relates to an integrated chip structure including a MEMS (microelectromechanical system) actuator having a mass block coupled to a frame via one or more curved cantilever arms.

[0095] In some embodiments, the present invention relates to an integrated chip structure. The integrated chip structure includes a MEMS (microelectromechanical system) actuator, the MEMS actuator comprising: an anchor having a first plurality of branches extending outward from a central region of the anchor, each of the first plurality of branches including a first plurality of fingers; a mass surrounding the anchor and having a second plurality of branches extending inward from an inner sidewall of the mass, each of the second plurality of branches including a second plurality of fingers intersecting the first plurality of fingers, as viewed in a top view; one or more curved cantilever arms coupled between the mass and a frame, the frame enclosing the mass; and the one or more curved cantilever arms including a curved outer surface, as viewed in a top view, the curved outer surface having one or more inflection points. In some embodiments, the anchor comprises a cross shape having a first plurality of branches extending outward from a central region, each of the first plurality of branches being curved at a 90-degree angle. In some embodiments, the mass includes a closed loop enclosing the anchor. In some embodiments, the one or more curved cantilever arms extend laterally beyond one or more sidewalls of the second plurality of branches. In some embodiments, the curved outer surface of the one or more curved cantilever arms includes a curved outer surface having a plurality of inflection points.

[0096] In other embodiments, the present invention relates to an integrated chip structure. The integrated chip structure includes a MEMS actuator disposed above a substrate and having a frame coupled to a mass block via one or more curved cantilever arms; an image sensor integrated chip disposed on the MEMS actuator; and, as viewed in a top view of the one or more curved cantilever arms, the one or more curved cantilever arms include a curved outer surface having a plurality of inflection points respectively arranged between the inflection points. In some embodiments, the MEMS actuator further includes an anchor coupled to the substrate, and the mass block has a first plurality of fingers interlacing with a second plurality of fingers of the anchor. In some embodiments, the mass block includes a first plurality of branches respectively having the first plurality of fingers; and the MEMS actuator further includes an anchor having a second plurality of branches, the second plurality of branches each having a second plurality of fingers interlacing with the first plurality of branches. In some embodiments, the substrate includes a printed circuit board. In some embodiments, the frame encloses the mass block in a closed loop. In some embodiments, the one or more curved cantilever arms include four curved cantilever arms respectively arranged along different sides of the mass block. In some embodiments, as viewed in a top view of the mass block, one or more curved cantilever arms extend from a surface of the mass block facing a first direction to a surface of the frame facing an opposite second direction.

[0097] In some embodiments, the integrated chip structure further includes: a package surrounding the image sensor integrated chip and a MEMS actuator, the frame of the MEMS actuator being laterally coupled to a sidewall of the package; and an optical system having one or more lenses disposed within the package and configured to focus incident radiation onto the image sensor integrated chip. In some embodiments, the integrated chip structure further includes control circuitry disposed on a substrate and configured to generate an electrical signal configured to move a mass block in response to detected movement of the package. In some embodiments, as observed in a cross-sectional view, one or more curved cantilever arms each have a central region laterally surrounded on opposite sides by an outer region of the cantilever arm, the outer region of the cantilever arm including a dielectric pad surrounding a core material.

[0098] In other embodiments, the present invention relates to a method for forming an integrated chip structure. The method includes: providing a substrate having a lower semiconductor layer separated from the semiconductor layer by an insulating layer; patterning the semiconductor layer to form a plurality of curved trenches on opposite sides of a cantilever region, forming a first plurality of straight trenches on opposite sides of a mass region, and forming a second straight trench between a frame region and the plurality of curved trenches, wherein the plurality of curved trenches are separated from the first plurality of straight trenches by a first sacrificial region of the semiconductor layer, and from the second straight trenches by a second sacrificial region of the semiconductor layer; filling the plurality of curved trenches, the first plurality of straight trenches, and the second straight trenches with one or more filler materials; and removing the first and second sacrificial regions to form one or more curved cantilever arms separated from the mass and frame by a non-zero pitch, wherein the one or more curved cantilever arms have curved sidewalls extending continuously between the mass and frame. In some embodiments, the method further includes removing the semiconductor layer from below a portion of the mass to form a bottom surface of the mass, the bottom surface being separated from the insulating layer by a second non-zero pitch. In some embodiments, the plurality of curved trenches, the first plurality of straight trenches, and the second straight trench have a bottom defined by a horizontally extending surface of a semiconductor layer. In some embodiments, filling the plurality of curved trenches with one or more filler materials includes performing a thermal oxidation process to form a dielectric pad along the sidewalls of the semiconductor layer, the sidewalls of the semiconductor layer defining the plurality of curved trenches; and depositing polysilicon on the dielectric pad to completely fill the plurality of curved trenches. In some embodiments, the method further includes attaching an image sensor integrated chip to a mass block; and attaching a frame to the sidewalls of a package.

[0099] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand aspects of the invention. Those skilled in the art should understand that they can readily use this invention as a base to design or modify other processes and structures for implementing the same purposes and / or achieving the same advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent configurations do not depart from the spirit and scope of the invention, and that various changes, substitutions, and modifications can be made to them herein without departing from the spirit and scope of the invention.

Claims

1. An integrated chip structure, comprising: Microelectromechanical system actuators, including: An anchor, the anchor including a first plurality of branches extending outward from a central region of the anchor, each of the first plurality of branches including a first plurality of fingers; A mass block, surrounding the anchor and including a second plurality of branches extending inwardly from the inner sidewall of the mass block, wherein, in a top view, each of the second plurality of branches includes a second plurality of fingers intersecting with the first plurality of fingers; One or more curved cantilever arms are coupled between the mass block and a frame, the frame enclosing the mass block; and In the top view, the one or more curved cantilever arms include a curved outer surface having one or more inflection points.

2. The integrated chip structure according to claim 1, wherein, The anchor includes a cross shape having a plurality of branches extending outward from the central region, each of the plurality of branches being bent at a 90-degree angle.

3. The integrated chip structure according to claim 1, wherein, The mass block includes a closed loop that encloses the anchor.

4. The integrated chip structure according to claim 1, wherein, The one or more curved cantilever extends laterally beyond one or more sidewalls of the second plurality of branches.

5. The integrated chip structure according to claim 1, wherein, The curved outer surface of the one or more curved cantilever includes multiple inflection points.

6. An integrated chip structure, comprising: Microelectromechanical system actuator, disposed above a substrate and including a frame coupled to a mass block via one or more curved cantilever arms; An image sensor integrated chip is mounted on the microelectromechanical system actuator. as well as In a top view of the one or more curved cantilever arms, the one or more curved cantilever arms include a curved outer surface, which has a plurality of inflection points respectively arranged between the inflection points. In the cross-sectional view, the one or more curved cantilever arms each include a central region laterally surrounded on opposite sides by an outer region of the cantilever arm, the outer region of the cantilever arm including a dielectric pad surrounding the core material.

7. The integrated chip structure according to claim 6, wherein, The microelectromechanical system actuator further includes an anchor coupled to the substrate, and the mass block includes a first plurality of fingers that intersect with a second plurality of fingers of the anchor.

8. The integrated chip structure according to claim 6, in, The mass block includes a first plurality of branches, each having a first plurality of fingers; and The microelectromechanical system actuator further includes an anchor, which includes a second plurality of branches, each of which has a second plurality of fingers that intersect with the first plurality of branches.

9. The integrated chip structure according to claim 6, wherein, The substrate includes a printed circuit board.

10. The integrated chip structure according to claim 6, wherein, The frame encloses the mass block in a closed loop.

11. The integrated chip structure according to claim 6, wherein, The one or more curved cantilever arms include four curved cantilever arms arranged along different sides of the mass block, respectively.

12. The integrated chip structure according to claim 6, wherein, In the top view of the mass block, the one or more curved cantilever arms extend from the surface of the mass block facing a first direction to the surface of the frame facing the opposite second direction.

13. The integrated chip structure according to claim 6, further comprising: A package housing surrounding the image sensor integrated chip and the microelectromechanical system (MEMS) actuator, wherein the frame of the MEMS actuator is laterally coupled to the sidewall of the package housing; and An optical system includes one or more lenses disposed within the package and configured to focus incident radiation onto the image sensor integrated chip.

14. The integrated chip structure according to claim 13, further comprising: A control circuit is disposed on the substrate and configured to generate an electrical signal, wherein the electrical signal is configured to move the mass block in response to detected movement of the package.

15. The integrated chip structure according to claim 6, wherein, The core material includes polycrystalline silicon.

16. A method for forming an integrated chip structure, comprising: A substrate having a lower semiconductor layer is provided, the lower semiconductor layer being separated from the semiconductor layer by an insulating layer; The semiconductor layer is patterned to form a plurality of curved trenches on opposite sides of the cantilever region, a first plurality of straight trenches on opposite sides of the mass block region, and a second straight trench between the frame region and the plurality of curved trenches, wherein the plurality of curved trenches are separated from the first plurality of straight trenches by a first sacrificial region of the semiconductor layer, and are separated from the second straight trenches by a second sacrificial region of the semiconductor layer; The plurality of curved grooves, the first plurality of straight grooves, and the second straight groove are filled with one or more filler materials; and The first sacrificial region and the second sacrificial region are removed to form one or more curved cantilever arms, the one or more curved cantilever arms being separated from the mass block and the frame by a non-zero distance, wherein the one or more curved cantilever arms have curved sidewalls that extend continuously between the mass block and the frame.

17. The method of claim 16, further comprising: The semiconductor layer is removed from a portion of the mass block to form the bottom surface of the mass block, the bottom surface being separated from the insulating layer by a second non-zero spacing.

18. The method according to claim 16, wherein, The plurality of curved trenches, the first plurality of straight trenches, and the second straight trench have a bottom defined by a horizontally extending surface of the semiconductor layer.

19. The method of claim 16, wherein, Filling the plurality of curved grooves with one or more of the filler materials includes: Perform a thermal oxidation process to form dielectric pads along the sidewalls of the semiconductor layer, the sidewalls of the semiconductor layer defining the plurality of curved trenches; and Polycrystalline silicon is deposited on the dielectric liner to completely fill the plurality of curved trenches.

20. The method of claim 16, further comprising: The image sensor integrated chip is attached to the mass block; as well as The frame is attached to the side wall of the encapsulation box.

Images