Micro-electromechanical system device and method of forming the same

Abstract

Various embodiments of the present disclosure relate to a microelectromechanical system (MEMS) device. The MEMS device includes a dielectric structure disposed on a first semiconductor substrate, wherein the dielectric structure at least partially defines a cavity. A second semiconductor substrate is disposed on the dielectric structure. The second semiconductor substrate includes a movable body, wherein opposing sidewalls of the movable body are disposed between opposing sidewalls of the cavity. An anti-stiction structure is disposed between the movable body and the dielectric structure, wherein the anti-stiction structure is a first silicon-based semiconductor.

Description

Technical Field

[0001] Embodiments of the present invention relate to a micro-electromechanical system (MEMS) device and a method for forming the same. Background Art

[0002] A microelectromechanical system (MEMS) device is a microscopic device that integrates mechanical and electronic components to sense physical quantities and / or act according to the surrounding environment. In recent years, MEMS devices have become increasingly common. For example, the use of MEMS devices as sensing devices (e.g., motion sensing devices, pressure sensing devices, acceleration sensing devices, etc.) has become widespread in many current personal electronic devices (e.g., smartphones, fitness electronics, personal computing devices). MEMS devices are also used in other applications, such as automotive applications (e.g., for accident detection and airbag deployment systems), aerospace applications (e.g., for navigation systems), medical applications (e.g., for patient monitoring), etc. Summary of the Invention

[0003] In some embodiments, the present disclosure provides a microelectromechanical system (MEMS) device. The MEMS device includes a dielectric structure disposed on a first semiconductor substrate, wherein the dielectric structure at least partially defines a cavity. A second semiconductor substrate is disposed on the dielectric structure. The second semiconductor substrate includes a movable body, wherein opposing sidewalls of the movable body are disposed between opposing sidewalls of the cavity. An anti-stiction structure is disposed between the movable body and the dielectric structure, wherein the anti-stiction structure is a first silicon-based semiconductor.

[0004] In some embodiments, the present disclosure provides a microelectromechanical system (MEMS) device. The MEMS device includes a sensing circuit disposed on a first semiconductor substrate. An interlayer dielectric (ILD) structure is disposed above the first semiconductor substrate and the sensing circuit, wherein the ILD structure at least partially defines a cavity. An interconnect structure is embedded in the ILD structure, wherein the interconnect structure is electrically coupled to the sensing circuit. A second semiconductor substrate is disposed above the ILD structure. The second semiconductor substrate includes a movable body, wherein the relative sidewalls of the movable body are disposed between the relative sidewalls of the cavity. An anti-stiction structure is disposed between the movable body and the ILD structure, wherein the anti-stiction structure is a silicon-based semiconductor and is electrically coupled to the interconnect structure, and wherein the sensing circuit is configured to measure changes in capacitive coupling between the movable body and the anti-stiction structure.

[0005] In some embodiments, the present disclosure provides a method for forming a microelectromechanical system (MEMS) device. The method includes forming a sensing electrode on an interlayer dielectric (ILD) structure, wherein the ILD structure is disposed on a first semiconductor substrate. Forming an anti-stiction structure on the ILD structure, wherein the anti-stiction structure is a silicon-based semiconductor. Bonding a second semiconductor substrate to a third semiconductor substrate. Forming a movable body in the second semiconductor substrate. After bonding the second semiconductor substrate and the third semiconductor substrate together, bonding the second and third semiconductor substrates to the first semiconductor substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various aspects of the present disclosure will be best understood by reading the following detailed description in conjunction with the accompanying drawings. It should be noted that, in accordance with standard practice in the industry, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion.

[0007] Figure 1 Cross-sectional views of some embodiments of microelectromechanical systems (MEMS) devices having mechanically robust anti-stiction structures are shown.

[0008] Figure 2 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0009] Figure 3 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0010] Figure 4 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0011] Figure 5 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0012] Figure 6 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0013] Figure 7 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0014] Figure 8 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0015] Figure 9 Show Figure 1Cross-sectional views of some other embodiments of MEMS devices are shown.

[0016] Figure 10 Show Figure 1 Cross-sectional views of some other embodiments of MEMS devices are shown.

[0017] Figures 11A to 11E Show Figure 1 Various layouts of some embodiments of the anti-stiction structure are shown.

[0018] Figures 12A to 12C Show Figure 1 Various simplified layouts of MEMS devices are shown.

[0019] Figures 13 to 27 Shown for forming Figure 10 A series of cross-sectional views of some embodiments of MEMS devices are shown.

[0020] Figure 28 A flow chart illustrating some embodiments of a method of forming a microelectromechanical system (MEMS) device having a mechanically robust anti-stiction structure. DETAILED DESCRIPTION

[0021] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and arrangements are set forth below to simplify the disclosure. Of course, these are merely examples and are not intended to be limiting. For example, the following description of a first feature being formed "above" or "on" a second feature may include embodiments in which the first and second features are formed to be in direct contact, and may also include embodiments in which additional features may be formed between the first and second features so that the first and second features are not in direct contact. In addition, the present disclosure may reuse reference numbers and / or letters in various examples. This repetition is for the purposes of brevity and clarity and is not itself indicative of a relationship between the various embodiments and / or configurations discussed.

[0022] Furthermore, for ease of description, spatially relative terms, such as "beneath," "below," "lower," "above," and "upper," may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0023] Many MEMS devices (e.g., accelerometers, gyroscopes, etc.) include a movable body and a fixed electrode plate. The movable body has a flat surface that is aligned parallel to and spaced apart from the opposite flat surface of the fixed electrode plate. The movable body is displaced within a cavity in response to an external stimulus (e.g., pressure, acceleration, gravity, etc.). This displacement changes the distance between the movable body and the fixed electrode plate. The change in distance can be detected by a change in the capacitive coupling between the movable body and the fixed electrode and analyzed by appropriate circuitry to derive a measurement of a physical quantity associated with the change in distance, such as acceleration.

[0024] One of the design challenges faced by MEMS devices is preventing the movable body from sticking to adjacent components of the MEMS device (an effect known as stiction). One example of stiction occurring is when the movable body suddenly "sticks" to an adjacent surface during normal operation of the MEMS device. The movable body may "stick" to an adjacent surface due to any of several different effects, such as capillary forces, molecular van der Waals forces, or electrostatic forces between adjacent surfaces. The extent to which these effects cause this stiction can vary depending on many different factors, such as surface temperature, contact area between surfaces, contact potential difference between surfaces, whether the surface is hydrophilic or hydrophobic, and so on.

[0025] One partial solution to limiting such adhesion is to utilize a bumper structure disposed in the cavity. The bumper structure can limit any of several such adhesion effects, such as effectively reducing the overall contact area between the movable body and the adjacent surface. The bumper structure is typically made of a material (e.g., aluminum-copper (AlCu)) having a relatively low yield stress (e.g., less than or equal to about 1,000 megapascals (MPa)). However, because the bumper structure is typically made of a material having a relatively low yield stress, a relatively large impact force from the movable body can cause the bumper structure to deform (e.g., plastically deform). The resulting deformation of the bumper structure can reduce the effectiveness of the bumper structure in limiting future adhesion (e.g., because the deformation increases the overall contact area between the movable body and the deformed bumper structure).

[0026] Various embodiments of the present application relate to a MEMS device with a mechanically robust anti-adhesion structure. The MEMS device includes an interlayer dielectric (ILD) structure arranged on a first semiconductor substrate. The upper surface of the ILD structure at least partially defines the bottom of the cavity. The second semiconductor substrate is arranged on the ILD structure and includes a movable body. The movable body is configured to shift in the cavity in response to an external stimulus. The anti-adhesion structure is arranged between the movable body and the upper surface of the ILD structure. The anti-adhesion structure is a silicon-based semiconductor (e.g., polycrystalline silicon, monocrystalline silicon, amorphous silicon, etc.). Since the anti-adhesion structure is a silicon-based semiconductor, the anti-adhesion structure has a relatively high yield stress. Since the anti-adhesion structure has a relatively high yield stress (e.g., a yield stress between about 5,000 MPa and about 9,000 MPa), the relatively large impact force from the movable body may not deform the anti-adhesion structure (e.g., may not cause plastic deformation of the anti-adhesion structure). Therefore, the anti-stiction structure can improve the mechanical robustness of the MEMS device, thereby expanding practical applications (e.g., high-impact resistant MEMS devices) and / or improving device performance (e.g., improving the sensing performance of the MEMS device during its working life).

[0027] Figure 1 Cross-sectional views of some embodiments of a micro-electromechanical system (MEMS) device 100 having a mechanically robust anti-stiction structure 132 are shown.

[0028] like Figure 1 As shown in FIG, a MEMS device 100 includes a first semiconductor substrate 102. The first semiconductor substrate 102 may include any type of semiconductor body (e.g., single crystal silicon / complementary metal-oxide-semiconductor (CMOS) block, silicon-germanium (SiGe), silicon on insulator (SOI), etc.). One or more semiconductor devices 104 may be disposed on / in the first semiconductor substrate 102. The one or more semiconductor devices 104 may be or include, for example, metal-oxide-semiconductor (MOS) field-effect transistors (FETs), some other MOS devices, or some other semiconductor devices. In some embodiments, the one or more semiconductor devices 104 may be part of a sensing circuit 106. In other embodiments, the first semiconductor substrate 102 may be referred to as a complementary metal-oxide-semiconductor (CMOS) substrate.

[0029] An interlayer dielectric (ILD) structure 108 is disposed above the first semiconductor substrate 102 and the one or more semiconductor devices 104. An interconnect structure 110 (e.g., a copper interconnect) is embedded in the ILD structure 108. The interconnect structure 110 includes a plurality of conductive features (e.g., metal lines, metal vias, metal contacts, etc.). In some embodiments, the ILD structure 108 includes one or more stacked ILD layers, each of which may include a low-k dielectric (e.g., a dielectric material with a dielectric constant less than approximately 3.9), an oxide (e.g., silicon dioxide (SiO2)), etc. In other embodiments, the plurality of conductive features may include, for example, copper (Cu), aluminum (Al), tungsten (W), titanium (Ti), titanium nitride (TiN), aluminum-copper (AlCu), some other conductive material, or a combination thereof. In yet other embodiments, the ILD structure 108 may be referred to as a dielectric structure.

[0030] A second semiconductor substrate 112 is disposed over both the ILD structure 108 and the first semiconductor substrate 102. The second semiconductor substrate 112 may include any type of semiconductor body (e.g., single crystal silicon / CMOS bulk, SiGe, SOI, etc.). In some embodiments, the second semiconductor substrate 112 may have a first doping type (e.g., p-type / n-type). In other embodiments, the second semiconductor substrate 112 may be referred to as a MEMS substrate.

[0031] In some embodiments, the second semiconductor substrate 112 is bonded to the first semiconductor substrate 102 via a first bonding structure 114 (e.g., a eutectic bond structure). The first bonding structure 114 may include an upper bonding ring 116 disposed on a lower bonding ring 118. In some embodiments, the first bonding structure 114 is conductive. The lower bonding ring 118 may comprise, for example, AlCu, Cu, Al, Ti, gold (Au), tin (Sn), some other bonding material, or a combination thereof. The upper bonding ring 116 may comprise, for example, germanium (Ge), Cu, Al, Au, Sn, some other bonding material, or a combination thereof.

[0032] In some embodiments, a third semiconductor substrate 120 is disposed above both the second semiconductor substrate 112 and the first semiconductor substrate 102. The third semiconductor substrate 120 may include any type of semiconductor body (e.g., single crystal silicon / CMOS bulk, SiGe, SOI, etc.). In other embodiments, the third semiconductor substrate 120 may be referred to as a cap substrate. In some embodiments, the third semiconductor substrate 120 is bonded to the second semiconductor substrate 112 via a second bonding structure 122. The second bonding structure 122 may include, for example, Ge, SiO2, Cu, Al, Au, Sn, Ti, some other bonding material, or a combination thereof.

[0033] The ILD structure 108 at least partially defines a cavity 124. In some embodiments, the ILD structure 108, the second semiconductor substrate 112, the first bonding structure 114, the third semiconductor substrate 120, and the second bonding structure 122 at least partially define the cavity 124. In other embodiments, the third semiconductor substrate 120 and the second bonding structure 122 at least partially define an upper portion of the cavity 124, and the ILD structure 108 and the first bonding structure 114 at least partially define a lower portion of the cavity 124.

[0034] The second semiconductor substrate 112 includes a movable body 126 (e.g., a proof mass). The movable body 126 is part of the second semiconductor substrate 112 and is suspended in the cavity 124 by one or more tethers. The movable body 126 is configured to displace within the cavity 124 in response to an external stimulus (e.g., pressure, acceleration, gravity, etc.). In some embodiments, the movable body 126 can be electrically coupled to the sensing circuit 106 (e.g., via the interconnect structure 110, the first bonding structure 114, and a doped conductive path (not shown) disposed in the second semiconductor substrate 112).

[0035] A first sense electrode 128 is disposed within cavity 124. First sense electrode 128 is electrically coupled to interconnect structure 110 through one or more upper vias 130 (e.g., metal through-holes) of interconnect structure 110. In some embodiments, upper vias 130 of interconnect structure 110 may be the uppermost vias of interconnect structure 110. In other embodiments, first sense electrode 128 may be disposed within ILD structure 108. In yet other embodiments, first sense electrode 128 may be part of an upper conductive line (e.g., an upper metal line) of interconnect structure 110.

[0036] In some embodiments, interconnect structure 110 electrically couples first sensing electrode 128 to sensing circuit 106. In other embodiments, sensing circuit 106 is configured to measure and analyze changes in the capacitive coupling between movable object 126 and first sensing electrode 128 to derive a measurement of a physical quantity (e.g., acceleration) associated with changes in the distance between movable object 126 and first sensing electrode 128. In some embodiments, first sensing electrode 128 may comprise, for example, TiN, Cu, Al, W, AlCu, some other conductive material, or a combination thereof. In other embodiments, first sensing electrode 128 may have the same chemical composition as lower bonding ring 118.

[0037] An anti-stiction structure 132 is disposed in the cavity 124. The anti-stiction structure 132 is disposed between the movable body 126 and the ILD structure 108. In some embodiments, the anti-stiction structure 132 contacts the ILD structure 108. In other embodiments, the anti-stiction structure 132 is electrically conductive.

[0038] In some embodiments, the anti-stiction structure 132 includes a semiconductor material (e.g., silicon (Si), Ge, etc.). The anti-stiction structure 132 may be an undoped semiconductor (e.g., an intrinsic semiconductor) or a doped semiconductor (e.g., a non-intrinsic semiconductor). In other embodiments, the concentration of the first doping type dopant (e.g., n-type dopant) included in the anti-stiction structure 132 is higher than the concentration of the second doping type dopant (e.g., p-type dopant), or vice versa. In other embodiments, the anti-stiction structure 132 has a resistivity less than or equal to approximately 100 ohm-centimeter (Ω·cm). In yet other embodiments, the resistivity of the anti-stiction structure 132 is between approximately 0.5 milliohm-centimeter (mΩ·cm) and approximately 100 Ω·cm.

[0039] In some embodiments, the anti-adhesion structure 132 includes silicon. In this embodiment, the anti-adhesion structure 132 may be referred to as a silicon-based anti-adhesion structure. In other embodiments, the anti-adhesion structure 132 may be substantially composed of silicon. It should be understood that in some embodiments, the anti-adhesion structure 132 substantially composed of silicon may include a first doping type dopant and / or a second doping type dopant. In other embodiments, the anti-adhesion structure 132 may be a silicon-based semiconductor. The anti-adhesion structure 132 may be an amorphous solid (e.g., amorphous silicon). In other embodiments, the anti-adhesion structure 132 may be a crystalline solid (e.g., single crystal silicon, polycrystalline silicon, etc.). In other embodiments, the anti-adhesion structure 132 may be a single crystal solid (e.g., single crystal silicon). In yet other embodiments, the anti-adhesion structure 132 may be a polycrystalline solid (e.g., polycrystalline silicon).

[0040] In some embodiments, the anti-adhesion structure 132 may have a yield stress greater than or equal to 1,000 MPa. More specifically, the anti-adhesion structure 132 may have a yield stress greater than or equal to 5,000 MPa. More specifically, the anti-adhesion structure 132 may have a yield stress between 5,000 MPa and 9,000 MPa. In some embodiments, the anti-adhesion structure 132 has a chemical composition different from that of the first sensing electrode 128. For example, the anti-adhesion structure 132 may be silicon-based (e.g., monocrystalline silicon, polycrystalline silicon, or amorphous silicon) and the first sensing electrode 128 may be metal-based (e.g., TiN, W, AlCu, etc.). In other embodiments, the yield stress of the anti-adhesion structure 132 is greater than the yield stress of the first sensing electrode 128.

[0041] Since the anti-stiction structure 132 is a silicon-based semiconductor, the anti-stiction structure 132 has a relatively high yield stress. Due to the relatively high yield stress of the anti-stiction structure, a relatively large impact force on the anti-stiction structure (e.g., an impact force through the movable body 126) may not deform the anti-stiction structure 132 (e.g., may not cause plastic deformation of the anti-stiction structure 132). Therefore, the anti-stiction structure 132 can improve the mechanical robustness of the MEMS device 100, thereby expanding practical applications (e.g., high-impact MEMS devices) and / or improving device performance (e.g., improving the sensing performance of the MEMS device during its working life).

[0042] In some embodiments, the chemical composition of the anti-stiction structure 132 is different from the chemical composition of the lower coupling ring 118. For example, the lower coupling ring 118 may comprise titanium, while the anti-stiction structure 132 may be polysilicon. In other embodiments, the chemical composition of the anti-stiction structure 132 is different from both the first sensing electrode 128 and the lower coupling ring 118.

[0043] Figure 2 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0044] like Figure 2As shown in , the anti-adhesion structure 132 is electrically coupled to the interconnect structure 110. In some embodiments, the anti-adhesion structure 132 is electrically coupled to one or more upper vias (e.g., one or more metal through-holes) of the plurality of upper vias 130. The interconnect structure 110 may electrically couple the anti-adhesion structure 132 to the sensing circuit 106. In other embodiments, the sensing circuit 106 is configured to measure and analyze changes in the capacitive coupling between the movable body 126 and the anti-adhesion structure 132 to derive a measurement value of a physical quantity (e.g., acceleration) associated with a change in the distance between the movable body 126 and the anti-adhesion structure 132. In yet other embodiments, the interconnect structure 110 may electrically couple the anti-adhesion structure to a specific electrical connection (e.g., 5 volts, 0 volts, etc.).

[0045] Since the anti-adhesion structure 132 is conductive and electrically coupled to the sensing circuit 106, the anti-adhesion structure 132 can be used as a sensing electrode. In this embodiment, the anti-adhesion structure 132 can be spaced apart from the first sensing electrode 128 and used in combination with the first sensing electrode 128 as a second sensing electrode. Since the anti-adhesion structure 132 can be used in combination with the first sensing electrode 128 as a second sensing electrode, the performance of the MEMS device 100 can be improved (for example, increasing sensitivity, improving accuracy, reducing incorrect sensing errors, etc.). In other such embodiments, the anti-adhesion structure 132 can be used as the first sensing electrode 128. In other words, the anti-adhesion structure 132 and the first sensing electrode 128 can be the same structure. Since the anti-adhesion structure 132 can be used as the first sensing electrode 128, the cost of manufacturing the MEMS device 100 can be reduced (for example, reducing the number of photolithography / deposition processes, reducing the amount of deposited material, etc.).

[0046] Figure 2 , the first sensing electrode 128 and the anti-stiction structure 132 can comprise the same material. For example, both the first sensing electrode 128 and the anti-stiction structure 132 can comprise silicon. In other embodiments, both the first sensing electrode 128 and the anti-stiction structure 132 can consist essentially of silicon. Because the first sensing electrode 128 and the anti-stiction structure 132 can comprise the same material, the cost of manufacturing the MEMS device 100 can be reduced (e.g., by reducing the number of photolithography / deposition processes). In some embodiments, the chemical composition of the first sensing electrode 128 is different from the chemical composition of the lower bonding ring 118.

[0047] In some embodiments, both the first sensing electrode 128 and the anti-adhesion structure 132 may be silicon-based semiconductors. In other embodiments, the anti-adhesion structure 132 and the first sensing electrode 128 may have different chemical compositions (for example, Si and TiN, respectively). In other embodiments, the anti-adhesion structure 132 and the first sensing electrode 128 may have the same crystalline structure. For example, both the anti-adhesion structure 132 and the first sensing electrode 128 may be an amorphous solid (for example, amorphous silicon), a crystalline solid (for example, single crystal silicon, polycrystalline silicon, etc.), a single crystal solid (for example, single crystal silicon) or a polycrystalline solid (for example, polycrystalline silicon). Since the first sensing electrode 128 and the anti-adhesion structure 132 may have the same crystalline structure, the cost of manufacturing the MEMS device 100 can be reduced (for example, reducing the number of photolithography processes). In other embodiments, the anti-adhesion structure 132 and the first sensing electrode 128 may have different crystalline structures. For example, the anti-stiction structure 132 may be a crystalline solid and the first sensing electrode 128 may be an amorphous solid, or vice versa.

[0048] Figure 3 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0049] like Figure 3 As shown in , the anti-stiction structure 132 includes one or more outgassing substances 302. In some embodiments, the outgassing substance may be, for example, argon (Ar), hydrogen (H), nitrogen (N), some other outgassing substance, or a combination thereof. The one or more outgassing substances 302 are configured to increase the pressure inside the cavity 124 after the cavity 124 is sealed (or during the sealing of the cavity 124). In such an embodiment, the one or more outgassing substances 302 can increase the pressure inside the cavity 124 by outgassing from the anti-stiction structure 132 into the cavity 124. Since the anti-stiction structure 132 may include the one or more outgassing substances 302, the cost of manufacturing the MEMS device 100 can be reduced (for example, by reducing the number of photolithography / deposition / implantation processes for forming separate outgas structures). Furthermore, because the anti-stiction structure 132 is a silicon-based semiconductor, the anti-stiction structure 132 may have improved outgassing properties relative to other materials (eg, a silicon-based semiconductor outgassing structure may enable more efficient outgassing of the one or more outgassing substances 302 compared to a metal-based outgassing structure).

[0050] In some embodiments, the first sensing electrode 128 includes the one or more outgassing substances 302. Because the first sensing electrode 128 may include the one or more outgassing substances 302, the cost of manufacturing the MEMS device 100 may be reduced (for example, the number of photolithography / deposition / implantation processes for forming a separate outgassing structure may be reduced). In other embodiments, both the first sensing electrode 128 and the anti-stiction structure 132 include the one or more outgassing substances 302. Because the anti-stiction structure 132 and the first sensing electrode 128 may include the one or more outgassing substances 302, the pressure inside the cavity 124 may be improved (for example, increased pressure, improved control of pressure, etc.). The first sensing electrode 128 and the anti-stiction structure 132 may include the same one or more outgassing substances 302 and / or the same concentration of the one or more outgassing substances 302. In other embodiments, the first sensing electrode 128 may include a first set (or concentration) of the one or more outgassing substances 302, and the anti-stiction structure 132 may include a second set (or concentration) of the one or more outgassing substances 302, where the second set (or concentration) is different from the first set (or concentration).

[0051] Figure 4 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0052] like Figure 4 As shown in FIG, in some embodiments, MEMS device 100 includes a plurality of sensing electrodes 128a-128b. For example, the MEMS device may include a third sensing electrode 128a and a fourth sensing electrode 128b. It should be understood that in some embodiments, each of the plurality of sensing electrodes 128a-128b may include the features (e.g., structural features, chemical composition, etc.) described for the first sensing electrode 128, or vice versa. In some embodiments, the upper surfaces of the plurality of sensing electrodes 128a-128b are coplanar.

[0053] The third sensing electrode 128a and the fourth sensing electrode 128b may have the same chemical composition. In other embodiments, the third sensing electrode 128a and the fourth sensing electrode 128b may have a different chemical composition. In some embodiments, the third sensing electrode 128a and the fourth sensing electrode 128b may have the same crystalline structure. In other embodiments, the third sensing electrode 128a and the fourth sensing electrode 128b may have different crystalline structures.

[0054] In some embodiments, the anti-adhesion structure 132 may be provided on the fourth sensing electrode 128b. It should be understood that in some embodiments, the anti-adhesion structure 132 may be provided on the third sensing electrode 128a, or multiple anti-adhesion structures may be provided on the multiple sensing electrodes 128a to 128b respectively. The anti-adhesion structure 132 is provided between the movable element and the fourth sensing electrode 128b. In some embodiments, the upper surface of the anti-adhesion structure 132 is provided to be higher than the upper surface of the fourth sensing electrode 128b. In other embodiments, the opposite side walls of the anti-adhesion structure 132 are substantially aligned with the opposite side walls of the fourth sensing electrode 128b respectively. In yet other embodiments, the thickness of the movable body 126 is less than the thickness of the adjacent portions of the second semiconductor substrate 112. In such an embodiment, the bottommost surface of the movable body 126 may be provided between the bottommost surfaces of the adjacent portions of the second semiconductor substrate 112.

[0055] Figure 5 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0056] In some embodiments, the outermost wall of the fourth sensing electrode 128b is disposed between the outermost walls of the anti-stiction structure 132. In other embodiments, the anti-stiction structure 132 may extend vertically along the outermost wall of the fourth sensing electrode 128b. In still other embodiments, the anti-stiction structure 132 may cover the upper surface of the fourth sensing electrode 128b and the sidewalls of the fourth sensing electrode 128b. The anti-stiction structure 132 may contact both the ILD structure 108 and the fourth sensing electrode 128b.

[0057] Figure 6 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0058] like Figure 6 As shown in FIG, in some embodiments, the MEMS device 100 includes a plurality of anti-stiction structures 132a to 132c. For example, the MEMS device may include a first anti-stiction structure 132a, a second anti-stiction structure 132b, and a third anti-stiction structure 132c (not shown). Figure 6). It should be understood that in some embodiments, each of the multiple anti-adhesion structures 132a to 132c may include features (e.g., structural features, chemical compositions, etc.) described for the anti-adhesion structure 132, or vice versa. In some embodiments, the first anti-adhesion structure 132a and the second anti-adhesion structure 132b have the same chemical composition. In other embodiments, the first anti-adhesion structure 132a and the second anti-adhesion structure 132b have the same crystalline structure. In other embodiments, the first anti-adhesion structure 132a and the second anti-adhesion structure 132b may have different crystalline structures.

[0059] In some embodiments, the first sensing electrode 128 is disposed between two or more of the plurality of anti-stiction structures 132a to 132c. For example, the first sensing electrode 128 may be disposed between the first anti-stiction structure 132a and the second anti-stiction structure 132b. The upper surfaces of the plurality of anti-stiction structures 132a to 132c may be coplanar with the upper surface of the first sensing electrode 128.

[0060] Figure 7 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0061] like Figure 7 As shown in FIG, the upper surfaces of the plurality of anti-stiction structures 132a to 132c are disposed lower than the upper surface of the first sensing electrode 128. In some embodiments, the upper surfaces of the plurality of anti-stiction structures 132a to 132c are disposed between the upper surface of the first sensing electrode 128 and the bottom surface of the first sensing electrode 128. In other embodiments, the upper surfaces of the plurality of anti-stiction structures 132a to 132c are disposed lower than the bottom surface of the first sensing electrode 128. In still other embodiments, the first sensing electrode 128 is disposed on the first portion of the ILD structure 108 and the plurality of anti-stiction structures 132a to 132c may be disposed on the plurality of second portions of the ILD structure 108. The upper surface of the first portion of the ILD structure 108 may be disposed above the upper surfaces of the plurality of second portions of the ILD structure 108.

[0062] Figure 8 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0063] like Figure 8As shown in FIG, the upper surfaces of the plurality of anti-stiction structures 132a to 132c are disposed higher than the upper surface of the first sensing electrode 128. In some embodiments, the bottom surfaces of the plurality of anti-stiction structures 132a to 132c are disposed higher than the upper surface of the first sensing electrode 128. In other embodiments, the bottom surfaces of the plurality of anti-stiction structures 132a to 132c are disposed between the upper surface of the first sensing electrode 128 and the bottom surface of the first sensing electrode 128. In still other embodiments, the upper surface of the first portion of the ILD structure 108 is disposed lower than the upper surfaces of the plurality of second portions of the ILD structure 108. In still other embodiments, the upper surface of the first sensing electrode 128 is disposed lower than the uppermost surface of the ILD structure 108. In other embodiments, the uppermost surface of the ILD structure 108 may be disposed between the upper surface of the first sensing electrode 128 and the bottom surface of the first sensing electrode 128.

[0064] Figure 9 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0065] like Figure 9 , the third anti-stiction structure 132c extends into the ILD structure 108. In some embodiments, a first upper surface of the third anti-stiction structure 132c is arranged to be lower than the upper surface of the ILD structure 108 and a second surface of the third anti-stiction structure 132c is arranged to be higher than the upper surface of the ILD structure 108. In other embodiments, the third anti-stiction structure 132c extends in a horizontal direction along the upper surface of the ILD structure 108. The bottom surface of the third anti-stiction structure 132c may be arranged to be lower than the bottom surface of the first anti-stiction structure 132a, the second anti-stiction structure 132b and / or the first sensing electrode 128. In still other embodiments, the plurality of anti-stiction structures 132a to 132c are arranged on a first side of the first sensing electrode 128.

[0066] In some embodiments, an outgas structure 902 is provided in the ILD structure 108. The outgas structure 902 includes the one or more outgas substances 302. In other embodiments, the upper surface of the outgas structure 902 is coplanar with the upper surface of the ILD structure 108. The upper surface of the outgas structure 902 may be arranged to be lower than the upper surface of the first sensing electrode 128 and / or the upper surface of one or more anti-stiction structures of the plurality of anti-stiction structures 132a to 132c. The upper surface of the outgas structure 902 may be arranged to be lower than the bottom surface of the first sensing electrode 128 and / or the bottom surface of one or more anti-stiction structures of the plurality of anti-stiction structures 132a to 132c. In still other embodiments, the outgas structure 902 may be electrically coupled to one or more upper conductive vias 130 of the plurality of upper conductive vias 130.

[0067] In some embodiments, the outgas structure 902 comprises a semiconductor material. The outgas structure 902 may comprise silicon. In such embodiments, the outgas structure 902 may be referred to as a silicon-based outgas structure. The outgas structure 902 may consist essentially of silicon. In other embodiments, the outgas structure 902 may be a silicon-based semiconductor. The outgas structure 902 may be an amorphous solid. In other embodiments, the outgas structure 902 may be a crystalline solid. The outgas structure 902 may be a single crystalline solid. The outgas structure 902 may be a polycrystalline solid. Because the outgas structure 902 is a silicon-based semiconductor, the outgas structure 902 may have improved outgassing properties relative to other materials (e.g., a silicon-based semiconductor outgas structure may allow for more efficient outgassing of the one or more outgassing substances 302 compared to a metal-based outgas structure).

[0068] In some embodiments, the outgas structure 902 may have the same chemical composition as the multiple anti-adhesion structures 132a to 132c. Since the outgas structure 902 may have the same chemical composition as the multiple anti-adhesion structures 132a to 132c, the cost of making the MEMS device 100 can be reduced (for example, reducing the number of photolithography / deposition processes). In other embodiments, the outgas structure 902 has a chemical composition different from the multiple anti-adhesion structures 132a to 132c. In other embodiments, the outgas structure 902 has the same crystalline structure as the multiple anti-adhesion structures 132a to 132c. In other embodiments, the outgas structure 902 may have different crystalline structures from the multiple anti-adhesion structures 132a to 132c. In yet other embodiments, the outgas structure 902 may be arranged on the second side of the first sensing electrode 128, the second side of the first sensing electrode 128 being opposite to the first side of the first sensing electrode 128. In other embodiments, the outgas structure 902 may be arranged on the first side of the first sensing electrode 128.

[0069] Figure 10 Show Figure 1 Cross-sectional views of some other embodiments of the MEMS device 100 are shown.

[0070] like Figure 10As shown in , in some embodiments, the outgassing structure 902 and the plurality of anti-adhesion structures 132a to 132c include the one or more outgassing substances 302. For example, the first anti-adhesion structure 132a, the second anti-adhesion structure 132b, the third anti-adhesion structure 132c, and the outgassing structure 902 may include the one or more outgassing substances 302. In some embodiments, the outgassing structure 902 and the plurality of anti-adhesion structures 132a to 132c may include the same one or more outgassing substances 302 and / or the same concentration of the one or more outgassing substances 302. In other embodiments, the outgassing structure 902 may include a third set (or concentration) of the one or more outgassing substances 302 and each of the plurality of anti-adhesion structures 132a to 132c may include a fourth set (or concentration) of the one or more outgassing substances 302, the fourth set (or concentration) being different from the third set (or concentration).

[0071] In some embodiments, the top surface of the outgas structure 902 can be positioned lower than the top surface of the ILD structure 108. In other embodiments, the outgas structure 902 can be not electrically coupled to the interconnect structure 110. In such embodiments, the ILD structure 108 can contact the entire bottom surface of the outgas structure 902.

[0072] Figures 11A to 11E Show Figure 1 Various layouts of some embodiments of the anti-stiction structure 132 are shown.

[0073] like Figure 11A As shown in , the anti-adhesion structure 132 may have a square layout. Figure 11B As shown in , the anti-adhesion structure 132 may have a circular layout. Figure 11C As shown in , the anti-adhesion structure 132 may have a rectangular layout. Figure 11D As shown in , the anti-adhesion structure 132 may have a generally annular layout (eg, a square ring, a circular ring, a rectangular ring, etc.). Figure 11E As shown in FIG, the anti-adhesion structure 132 may have a C-shaped layout. Figures 11A to 11E The anti-stiction structures 132 are shown as having various geometric layouts, however it is understood that the anti-stiction structures 132 can have other geometric layouts.

[0074] In some embodiments, the anti-adhesion structure 132 may have a height between about 0.1 micrometer (μm) and about 10 μm (e.g., the height between the top surface and the bottom surface). In other embodiments, the anti-adhesion structure 132 may have a width between about 1 μm and about 100 μm. In other embodiments, the anti-adhesion structure 132 may have a length between about 1 μm and about 100 μm. In yet other embodiments, the anti-adhesion structure 132 may be arranged in an area with a length between about 1 μm and about 100 μm and a width between about 1 μm and about 100 μm. It should be understood that the above height range, width range, length range and area range are non-limiting examples, and depending on the size of the application of the MEMS device 100 and / or the MEMS device 100, the height of the anti-adhesion structure 132, the width of the anti-adhesion structure 132, the length of the anti-adhesion structure 132 and / or the area where the anti-adhesion structure 132 is arranged may be outside the above range (e.g., less than or greater than the above range).

[0075] Figures 12A to 12C Show Figure 1 Various simplified layouts of the MEMS device 100 are shown. Figures 12A to 12C It is “simplified” because: the third semiconductor substrate 120 is not shown, the second bonding structure 122 is not shown, the second semiconductor substrate 112 is not shown, the first bonding structure 114 is not shown, the interconnect structure 110 is not shown, the first sensing electrode 128 is not shown, the perimeter of the cavity 124 is shown by a first dotted line, and the perimeter of the movable body 126 is shown by a second dotted line.

[0076] like Figure 12A As shown in FIG, in some embodiments, the MEMS device 100 may include only a single anti-stiction structure 132. In other embodiments, the layout of the anti-stiction structure 132 may be vertically aligned with the perimeter of the movable body 126. For example, the anti-stiction structure 132 may be disposed on the ILD structure 108 such that the edge of the movable body 126 is disposed between the inner and outer sidewalls of the anti-stiction structure 132. In other embodiments, the anti-stiction structure 132 may be disposed inside the perimeter of the movable body 126 or outside the perimeter of the movable body 126.

[0077] like Figure 12BAs shown in , in some embodiments, the MEMS device 100 may include the multiple anti-adhesion structures 132a to 132c. In some embodiments, each of the multiple anti-adhesion structures 132a to 132c may have the same geometric layout (e.g., a rectangular layout). The multiple anti-adhesion structures 132a to 132c may be aligned with the perimeter of the movable body 126 in the vertical direction. In other embodiments, the multiple anti-adhesion structures 132a to 132c may be arranged inside the perimeter of the movable body 126 or outside the perimeter of the movable body 126. In some embodiments, some of the multiple anti-adhesion structures 132a to 132c anti-adhesion structures may be aligned with the perimeter of the movable body 126 in the vertical direction, and some other anti-adhesion structures of the multiple anti-adhesion structures 132a to 132c may be arranged inside the perimeter of the movable body 126 and / or outside the perimeter of the movable body 126. For example, the first and second anti-sticking structures 132a and 132b may be vertically aligned with the perimeter of the movable body 126, and the third anti-sticking structure 132c may be disposed inside the perimeter of the movable body 126 (or outside the perimeter of the movable body 126).

[0078] like Figure 12C As shown in , some of the plurality of anti-adhesion structures 132a to 132c may have a geometric layout different from some other anti-adhesion structures of the plurality of anti-adhesion structures 132a to 132c. For example, the first anti-adhesion structure 132a may have a first geometric layout (e.g., a circular layout), the second anti-adhesion structure 132b may have a second geometric layout (e.g., a square ring layout) different from the first geometric layout, and the third anti-adhesion structure 132c may have a third geometric layout (e.g., a C-shaped layout) different from the first and second geometric layouts.

[0079] Figures 13 to 27 Shown for forming Figure 10 A series of cross-sectional views of some embodiments of MEMS device 100 are shown.

[0080] like Figure 13 As shown in FIG, an interlayer dielectric (ILD) structure 108 is disposed on a first semiconductor substrate 102. An interconnect structure 110 is disposed in the ILD structure 108. In addition, the interconnect structure 110 includes a plurality of upper vias 130. In addition, one or more semiconductor devices 104 are disposed on / in the first semiconductor substrate 102.

[0081] In some embodiments, forming Figure 13The method for forming the structure shown in includes forming the one or more semiconductor devices 104 by forming a source / drain region pair in a first semiconductor substrate 102 (e.g., by ion implantation). Thereafter, a gate dielectric and a gate electrode are formed over the first semiconductor substrate 102 and between the source / drain region pair (e.g., by deposition / growth and etching processes). A first ILD layer is then formed over the one or more semiconductor devices 104, and contact openings are formed in the first ILD layer. A conductive material (e.g., W) is formed over the first ILD layer and in the contact openings. Thereafter, a planarization process (e.g., chemical-mechanical polishing (CMP)) is performed on the conductive material to form conductive contacts (e.g., metal contacts) in the first ILD layer.

[0082] A second ILD layer is then formed over the first ILD layer and the conductive contacts, and a first conductive line trench is formed in the second ILD layer. A conductive material (e.g., Cu) is formed over the second ILD layer and in the first conductive line trench. A planarization process (e.g., CMP) is then performed on the conductive material to form a conductive line (e.g., a metal line) in the second ILD layer. A third ILD layer is then formed over the second ILD layer and the conductive line, and a via opening is formed in the third ILD layer. A conductive material (e.g., Cu) is formed over the third ILD layer and in the via opening. A planarization process (e.g., CMP) is then performed on the conductive material to form a via (e.g., a metal through-hole) in the third ILD layer. The above process for forming the conductive lines and vias may be repeated any number of times to form the interconnect structure 110. In some embodiments, forming the plurality of upper vias 130 (e.g., formed by the above process for forming vias) completes the formation of the interconnect structure 110. In other embodiments, forming an upper conductive line (e.g., a top metal) completes the formation of the interconnect structure 110. In other embodiments, the above layers and / or structures may be formed using deposition or growth processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), thermal oxidation, sputtering, electrochemical plating, electroless plating, some other deposition or growth processes, or a combination thereof.

[0083] like Figure 14As shown in FIG, a first opening 1402 is formed in the ILD structure 108. In some embodiments, the process of forming the first opening 1402 includes forming a patterned masking layer (not shown) (e.g., a negative / positive photoresist) on the ILD structure 108 and the upper via 130 (e.g., formed by a deposition process and a photolithography process). Thereafter, the ILD structure 108 is exposed to an etchant (e.g., a wet / dry etchant) to remove the unmasked portion of the ILD structure 108, thereby forming the first opening 1402.

[0084] like Figure 15 As shown in FIG, on the ILD structure 108, on the plurality of upper vias 130 and on the first opening 1402 (see, for example, Figure 14 ) to form an outgassing layer 1502. The outgassing layer 1502 includes one or more outgassing substances 302. The outgassing substances may be, for example, argon (Ar), hydrogen (H), nitrogen (N), some other outgassing substances, or a combination thereof. In other embodiments, the outgassing layer 1502 includes a semiconductor material. The outgassing layer 1502 may include silicon. In such embodiments, the outgassing layer 1502 may be referred to as a silicon-based outgassing layer. The outgassing layer 1502 may consist essentially of silicon. In yet other embodiments, the outgassing layer 1502 may be a silicon-based semiconductor. The outgassing layer 1502 may be an amorphous solid. In other embodiments, the outgassing layer 1502 may be a crystalline solid. The outgassing layer 1502 may be a single crystalline solid. The outgassing layer 1502 may be a polycrystalline solid.

[0085] In some embodiments, the process of forming the outgas layer 1502 includes depositing the outgas layer 1502 on the ILD structure 108, on the plurality of upper vias 130, and in the first opening 1402. The outgas layer 1502 can be deposited by, for example, sputtering, CVD, PVD, ALD, some other deposition process, or a combination thereof. In other embodiments, the one or more outgas species 302 are formed in the outgas layer 1502 during (or after) the formation of the outgas layer 1502. For example, the one or more outgas species 302 can be pumped into the processing chamber during the deposition of the outgas layer 1502, thereby forming the outgas layer 1502 having the one or more outgas species 302 therein.

[0086] like Figure 16 As shown in FIG, an outgas structure 902 is formed in the ILD structure 108. In some embodiments, the outgas structure 902 is formed to have an upper surface coplanar with an upper surface of the ILD structure 108. In some embodiments, the process of forming the outgas structure 902 includes: Figure 15) a planarization process 1602 (e.g., CMP) is performed to remove an upper portion of the outgas layer 1502, thereby forming the outgas structure 902. In yet other embodiments, the planarization process 1602 may be performed on the outgas layer 1502 and the ILD structure 108 to make the upper surface of the outgas structure 902 coplanar with the upper surface of the ILD structure 108. In some embodiments, the process of forming the outgas structure 902 may be referred to as a damascene formation process.

[0087] like Figure 17 As shown in FIG, a first sense electrode 128 and a lower coupling ring 118 are formed over the ILD structure 108. In some embodiments, the process for forming the first sense electrode 128 and the lower coupling ring 118 includes depositing a conductive layer (not shown) over the ILD structure 108, the outgas structure 902, and the plurality of upper vias 130. The conductive layer can be deposited by, for example, CVD, PVD, ALD, sputtering, electrochemical plating, electroless plating, donor wafer bonding deposition (e.g., bonding a single crystalline silicon SOI wafer to the ILD structure 108), some other deposition process, or a combination thereof. A patterned masking layer (not shown) is then formed over the conductive layer. Thereafter, the conductive layer is exposed to an etchant to remove unmasked portions of the conductive layer, thereby forming the first sense electrode 128 and the lower coupling ring 118. Subsequently, in some embodiments, the patterned masking layer is stripped.

[0088] It should be understood that the first sense electrode 128 and the lower coupling ring 118 can be formed using multiple conductive layers, multiple patterned masking layers, and multiple etching processes (e.g., exposing the layers to an etchant). For example, a first conductive layer (e.g., Si) can be deposited over the ILD structure 108, the outgassing structure 902, and the plurality of upper vias 130. In some embodiments, the first conductive layer can be formed to include the one or more outgassing species 302 in the first layer. A first patterned masking layer is then formed over the first conductive layer. Thereafter, the first conductive layer is exposed to a first etchant to remove unmasked portions of the first conductive layer, thereby forming the first sense electrode 128. Subsequently, in some embodiments, the first patterned masking layer is stripped.

[0089] A second conductive layer (e.g., TiN) is then deposited over the ILD structure 108, the outgas structure 902, the plurality of upper vias 130, and the first sense electrode 128. A second patterned masking layer is then formed over the second conductive layer. The second conductive layer is then exposed to a second etchant to remove unmasked portions of the second conductive layer, thereby forming the lower coupling ring 118. Subsequently, in some embodiments, the second patterned masking layer is stripped. It should be understood that in some embodiments, the lower coupling ring 118 may be formed before the first sense electrode 128.

[0090] like Figure 18 As shown in FIG, a second opening 1802 is formed in the ILD structure 108. In some embodiments, the process of forming the second opening 1802 includes forming a patterned masking layer (not shown) over the ILD structure 108, the outgassing structure 902, the first sense electrode 128, the lower bonding ring 118, and the upper vias 130. Thereafter, the ILD structure 108 is exposed to an etchant to remove unmasked portions of the ILD structure 108 and unmasked portions of the plurality of upper vias 130, thereby forming the second opening 1802.

[0091] It should be understood that in some embodiments, the ILD structure 108 may include multiple ILD layers, wherein one or more of the plurality of upper vias 130 are disposed in the plurality of ILD layers. For example, a first upper via among the plurality of upper vias 130 may be disposed in the first ILD layer. The first upper via has a first height. A second ILD layer may be disposed above the first ILD layer and the first upper via. A second upper via among the plurality of upper vias 130 may be disposed in both the first and second ILD layers. The second upper via has a second height greater than the first height. In other embodiments, the second opening 1802 may be formed above the first upper via and in the second ILD layer.

[0092] like Figure 19 As shown in , an anti-adhesion layer 1902 is formed over the ILD structure 108, the first sensing electrode 128, the lower coupling ring 118, the outgassing structure 902, and the plurality of upper vias 130. The anti-adhesion layer 1902 comprises a semiconductor material. The anti-adhesion layer 1902 may comprise silicon. In such an embodiment, the anti-adhesion layer 1902 may be referred to as a silicon-based anti-adhesion layer. The anti-adhesion layer 1902 may be substantially composed of silicon. In yet other embodiments, the anti-adhesion layer 1902 may be a silicon-based semiconductor. The anti-adhesion layer 1902 may be an amorphous solid. In other embodiments, the anti-adhesion layer 1902 may be a crystalline solid. The anti-adhesion layer 1902 may be a single crystalline solid. The anti-adhesion layer 1902 may be a polycrystalline solid.

[0093] In some embodiments, the anti-adhesion layer 1902 and the first sensing electrode 128 may be silicon-based semiconductors. In other embodiments, the anti-adhesion layer 1902 and the first sensing electrode 128 may have different chemical compositions (for example, Si and TiN, respectively). In some embodiments, the anti-adhesion layer 1902 and the first sensing electrode 128 may have the same crystalline structure. For example, both the anti-adhesion layer 1902 and the first sensing electrode 128 may be an amorphous solid (for example, amorphous silicon), a crystalline solid (for example, single crystal silicon, polycrystalline silicon, etc.), a single crystal solid (for example, single crystal silicon) or a polycrystalline solid (for example, polycrystalline silicon). In other embodiments, the anti-adhesion layer 1902 and the first sensing electrode 128 may have different crystalline structures. For example, the anti-adhesion layer 1902 may be a crystalline solid, while the first sensing electrode 128 may be an amorphous solid, or vice versa.

[0094] In some embodiments, the anti-stiction layer 1902 may include one or more outgassing substances 302. The first sensing electrode 128 and the anti-stiction layer 1902 may include the same one or more outgassing substances 302 and / or the same concentration of the one or more outgassing substances 302. In other embodiments, the first sensing electrode 128 may include a first set (or concentration) of the one or more outgassing substances 302, and the anti-stiction layer 1902 may include a second set (or concentration) of the one or more outgassing substances 302, the second set (or concentration) being different from the first set (or concentration).

[0095] In some embodiments, the process of forming the anti-stiction layer 1902 includes depositing the anti-stiction layer 1902 on the ILD structure 108, the lower bonding ring 118, the first sensing electrode 128, the outgassing structure 902, and the plurality of upper vias 130, and forming the second opening 1802 (see, for example, FIG. Figure 18 ) for lining. The anti-stiction layer 1902 can be deposited by, for example, CVD, PVD, ALD, sputtering, donor wafer bonding deposition, some other deposition process, or a combination thereof. In other embodiments, the one or more outgassing substances 302 are formed in the anti-stiction layer 1902 during (or after) the formation of the anti-stiction layer 1902. For example, the one or more outgassing substances 302 can be pumped into the processing chamber during the deposition of the anti-stiction layer 1902, thereby forming the anti-stiction layer 1902 having the one or more outgassing substances 302 therein.

[0096] like Figure 20 As shown in FIG, a plurality of anti-stiction structures 132a to 132c are formed on / in the ILD structure 108. In some embodiments, the process of forming the plurality of anti-stiction structures 132a to 132c includes forming an anti-stiction layer 1902 (see, for example, FIG. Figure 19) is deposited on a patterned masking layer (not shown). Thereafter, an etching process 2002 is performed on the anti-stiction layer 1902 having the patterned masking layer in an appropriate position. The etching process 2002 includes exposing the anti-stiction layer 1902 to an etchant to remove the unmasked portion of the anti-stiction layer 1902, thereby forming the multiple anti-stiction structures 132a to 132c. Subsequently, in some embodiments, the patterned masking layer is stripped off. In other embodiments, the etching process 2002 may remove the upper portion of the outgas structure 902 so that the upper surface of the outgas structure 902 is set to be lower than the upper surface of the ILD structure 108. It should be understood that in some embodiments, the first sensing electrode 128 and the multiple anti-stiction structures 132a to 132c may be formed by the same process (for example, an embodiment in which the first sensing electrode 128 and the multiple anti-stiction structures 132a to 132c are all silicon-based semiconductors). In some further embodiments, the process of forming the plurality of anti-stiction structures 132 a to 132 c is referred to as a layout patterning process.

[0097] like Figure 21 As shown in FIG, a plurality of third openings 2102 are formed in the third semiconductor substrate 120. In some embodiments, the process of forming the plurality of third openings 2102 includes forming a patterned masking layer (not shown) on the third semiconductor substrate 120. Thereafter, the third semiconductor substrate 120 is exposed to an etchant to remove unmasked portions of the third semiconductor substrate 120, thereby forming the plurality of third openings 2102. Subsequently, in some embodiments, the patterned masking layer is stripped.

[0098] like Figure 22 As shown in , a second bonding structure 122 is formed on the third semiconductor substrate 120. In some embodiments, the process of forming the second bonding structure includes depositing or growing a first bonding layer (not shown) on the third semiconductor substrate 120 and lining the plurality of third openings 2102. A patterned masking layer (not shown) is then formed on the first bonding layer. Thereafter, the first bonding layer is exposed to an etchant to remove unmasked portions of the first bonding layer, thereby forming the second bonding structure 122. Subsequently, in some embodiments, the patterned masking layer is stripped. In some embodiments, the first bonding layer can be deposited or grown by, for example, CVD, PVD, ALD, thermal oxidation, sputtering, an epitaxy process, electrochemical plating, electroless plating, some other deposition or growth process, or a combination thereof. In other embodiments, the first bonding layer can include, for example, Ge, SiO2, Cu, Al, Au, Sn, Ti, some other bonding material, or a combination thereof. It should be understood that in some embodiments, the second bonding structure 122 can be formed before forming the plurality of third openings 2102.

[0099] like Figure 23 As shown in FIG, the second semiconductor substrate 112 is bonded to the third semiconductor substrate 120. In some embodiments, the second semiconductor substrate 112 is bonded to the third semiconductor substrate 120 via a second bonding structure 122. In other embodiments, the process of bonding the second semiconductor substrate 112 to the third semiconductor substrate 120 includes positioning the second semiconductor substrate 112 so that the second semiconductor substrate 112 is aligned with the third semiconductor substrate 120 and faces the second bonding structure 122. Thereafter, the second semiconductor substrate 112 is bonded to the second bonding structure 122 (e.g., by a direct bonding process), thereby bonding the second semiconductor substrate 112 to the third semiconductor substrate 120. It should be understood that in some embodiments, the second semiconductor substrate 112 can be bonded to the third semiconductor substrate 120 via a different bonding process (e.g., a hybrid bonding process, a eutectic bonding process, etc.).

[0100] like Figure 24 As shown in FIG, a fourth opening 2402 is formed in the second semiconductor substrate 112. The fourth opening 2402 reduces the thickness of a portion of the second semiconductor substrate 112. In some embodiments, the process of forming the fourth opening 2402 includes forming a patterned masking layer (not shown) on the second semiconductor substrate 112. Thereafter, the second semiconductor substrate 112 is exposed to an etchant to remove the unmasked portion of the second semiconductor substrate 112, thereby forming the fourth opening 2402. Subsequently, in some embodiments, the patterned masking layer is stripped.

[0101] like Figure 25 As shown in , an upper bonding ring 116 is formed on the second semiconductor substrate 112. In some embodiments, the upper bonding ring 116 is formed to surround the fourth opening 2402 in the laterally direction. In other embodiments, the process of forming the upper bonding ring 116 includes depositing or growing a second bonding layer (not shown) on the second semiconductor substrate 112 and lining the fourth opening 2402. A patterned masking layer (not shown) is then formed on the second bonding layer. Thereafter, the second bonding layer is exposed to an etchant to remove the unmasked portion of the second bonding layer, thereby forming the upper bonding ring 116. Subsequently, in some embodiments, the patterned masking layer is stripped off. In other embodiments, the second bonding layer may be deposited or grown by, for example, the following processes: CVD, PVD, ALD, thermal oxidation, sputtering, epitaxial process, electrochemical plating, electroless plating, some other deposition or growth process, or a combination of the above. In yet other embodiments, the second bonding layer may include, for example, Ge, Cu, Al, Au, Sn, some other bonding material, or a combination of the above. It should be understood that in some embodiments, the upper coupling ring 116 may be formed before forming the fourth opening 2402 .

[0102] like Figure 26 As shown in FIG, a movable body 126 is formed in the second semiconductor substrate 112. In some embodiments, the process of forming the movable body 126 includes forming a patterned mask layer (not shown) on the second semiconductor substrate 112 and the upper coupling ring 116, and forming a patterned mask layer (not shown) on the fourth opening 2402 (see, for example, FIG). Figure 24 ) is lined. Thereafter, the second semiconductor substrate 112 is exposed to an etchant to remove the unmasked portion of the second semiconductor substrate 112, thereby forming the movable body 126. Subsequently, in some embodiments, the patterned masking layer is stripped.

[0103] like Figure 27 As shown in FIG, both the second semiconductor substrate 112 and the third semiconductor substrate 120 are bonded to the first semiconductor substrate 102. In some embodiments, the second semiconductor substrate 112 and the third semiconductor substrate 120 are bonded to the first semiconductor substrate 102 via an upper bonding ring 116 and a lower bonding ring 118. In other embodiments, the process of bonding the second semiconductor substrate 112 and the third semiconductor substrate 120 to the first semiconductor substrate 102 includes positioning the second semiconductor substrate 112 and the third semiconductor substrate 120 so that the upper bonding ring 116 is aligned with and faces the lower bonding ring 118. Thereafter, the upper bonding ring 116 is bonded to the lower bonding ring 118 (e.g., via a eutectic bonding process), thereby bonding the second semiconductor substrate 112 and the third semiconductor substrate 120 to the first semiconductor substrate 102. It should be understood that in some embodiments, the second semiconductor substrate 112 and the third semiconductor substrate 120 may be bonded to the first semiconductor substrate 102 via a different bonding process (e.g., a hybrid bonding process, a eutectic bonding process, etc.).

[0104] In some embodiments, bonding the upper bonding ring 116 to the lower bonding ring 118 forms a first bonding structure 114 that laterally surrounds the movable body 126. In other embodiments, bonding the second semiconductor substrate 112 and the third semiconductor substrate 120 to the first semiconductor substrate 102 forms a cavity 124 in which the movable body 126 is disposed. In other embodiments, after bonding the second semiconductor substrate 112 and the third semiconductor substrate 120 to the first semiconductor substrate 102, the one or more outgassing substances 302 are outgassed into the cavity 124 (e.g., by heating the MEMS device 100 to an outgassing temperature). In yet other embodiments, after bonding the second semiconductor substrate 112 and the third semiconductor substrate 120 to the first semiconductor substrate 102, formation of the MEMS device 100 is complete.

[0105] Figure 28Flowchart showing some embodiments of a method of forming a microelectromechanical system (MEMS) device having a mechanically robust anti-stiction structure. Figure 28 The illustrated flow chart 2800 is shown and described as a series of actions or events, however, it should be understood that the order in which such actions or events are shown should not be construed as limiting. For example, some actions may occur in a different order and / or synchronously with other actions or events other than those shown and / or described herein. Furthermore, not all of the illustrated actions may be required to implement one or more aspects or embodiments described herein, and one or more of the illustrated actions may be performed in one or more separate actions and / or stages.

[0106] At act 2802 , a sensing electrode is formed on / in an interlayer dielectric (ILD) structure, wherein the ILD structure is disposed over a first semiconductor substrate. Figure 17 A cross-sectional view of some embodiments is shown corresponding to act 2802. In some embodiments, an outgassing structure can be formed in the ILD structure before forming the sense electrode (or after forming the sense electrode). Figures 13 to 16 A series of cross-sectional views illustrating some embodiments for forming outgassing structures.

[0107] At act 2804 , one or more anti-stiction structures are formed over / in the ILD structure, wherein the one or more anti-stiction structures are a silicon-based semiconductor. Figures 18 to 20 A series of cross-sectional views of some embodiments corresponding to act 2804 are shown.

[0108] At act 2806 , the second semiconductor substrate is bonded to a third semiconductor substrate. Figures 21 to 25 A series of cross-sectional views of some embodiments corresponding to act 2806 are shown.

[0109] At act 2808 , a movable body is formed in the second semiconductor substrate. Figure 26 A cross-sectional view of some embodiments corresponding to act 2808 is shown.

[0110] At act 2810 , both the second semiconductor substrate and the third semiconductor substrate are bonded to the first semiconductor substrate. Figure 27 A cross-sectional view of some embodiments corresponding to act 2810 is shown.

[0111] In some embodiments, the present disclosure provides a microelectromechanical system (MEMS) device. The MEMS device includes a dielectric structure disposed on a first semiconductor substrate, wherein the dielectric structure at least partially defines a cavity. A second semiconductor substrate is disposed on the dielectric structure. The second semiconductor substrate includes a movable body, wherein opposing sidewalls of the movable body are disposed between opposing sidewalls of the cavity. An anti-stiction structure is disposed between the movable body and the dielectric structure, wherein the anti-stiction structure is a first silicon-based semiconductor.

[0112] In some embodiments, the MEMS device further comprises: an interconnect structure disposed in the dielectric structure, wherein the anti-stiction structure is electrically coupled to the interconnect structure. In some embodiments, the resistivity of the anti-stiction structure is between about 0.5 milliohm-centimeters (mΩ·cm) and about 100 ohm-centimeters (Ω·cm). In some embodiments, the anti-stiction structure comprises one or more outgassing substances. In some embodiments, the MEMS device further comprises: a first electrode disposed between the movable body and the dielectric structure, wherein the first electrode comprises a first chemical composition and the anti-stiction structure comprises a second chemical composition different from the first chemical composition, and wherein the anti-stiction structure has a yield stress greater than a yield stress of the first electrode. In some embodiments, the MEMS device further comprises: a second electrode disposed between the movable body and the dielectric structure, wherein: the second electrode is disposed between the anti-stiction structure and the dielectric structure; the second electrode contacts both the dielectric structure and the anti-stiction structure; and the second electrode has a third chemical composition that is the same as the first chemical composition. In some embodiments, the MEMS device further comprises: an electrode disposed between the movable body and the dielectric structure, wherein the uppermost surface of the anti-adhesion structure is disposed lower than the uppermost surface of the electrode. In some embodiments, the MEMS device further comprises: an electrode disposed between the movable body and the dielectric structure, wherein the uppermost surface of the anti-adhesion structure is disposed higher than the uppermost surface of the electrode. In some embodiments, the MEMS device further comprises: an electrode disposed between the movable body and the dielectric structure, wherein the uppermost surface of the anti-adhesion structure is coplanar with the uppermost surface of the electrode. In some embodiments, the MEMS device further comprises: an electrode disposed between the movable body and the dielectric structure, wherein the electrode is a second silicon-based semiconductor. In some embodiments, both the electrode and the anti-adhesion structure are amorphous solids. In some embodiments, both the electrode and the anti-adhesion structure are crystalline solids. In some embodiments, the electrode is a crystalline solid and the anti-adhesion structure is an amorphous solid. In some embodiments, the electrode is an amorphous solid and the anti-adhesion structure is a crystalline solid.

[0113] In some embodiments, the present disclosure provides a microelectromechanical system (MEMS) device. The MEMS device includes a sensing circuit disposed on a first semiconductor substrate. An interlayer dielectric (ILD) structure is disposed above the first semiconductor substrate and the sensing circuit, wherein the ILD structure at least partially defines a cavity. An interconnect structure is embedded in the ILD structure, wherein the interconnect structure is electrically coupled to the sensing circuit. A second semiconductor substrate is disposed above the ILD structure. The second semiconductor substrate includes a movable body, wherein the relative sidewalls of the movable body are disposed between the relative sidewalls of the cavity. An anti-stiction structure is disposed between the movable body and the ILD structure, wherein the anti-stiction structure is a silicon-based semiconductor and is electrically coupled to the interconnect structure, and wherein the sensing circuit is configured to measure changes in capacitive coupling between the movable body and the anti-stiction structure.

[0114] In some embodiments, the anti-adhesion structure has a first upper surface and a second upper surface, the first upper surface is arranged to be lower than the uppermost surface of the interlayer dielectric structure, and the second upper surface is arranged to be higher than the uppermost surface of the interlayer dielectric structure. In some embodiments, the MEMS device further comprises: a silicon-based outgassing structure arranged between the movable body and the interlayer dielectric structure, wherein the silicon-based outgassing structure is spaced apart from the anti-adhesion structure. In some embodiments, the uppermost surface of the silicon-based outgassing structure is coplanar with the uppermost surface of the interlayer dielectric structure, and wherein the uppermost surface of the anti-adhesion structure is arranged to be higher than the uppermost surface of the silicon-based outgassing structure. In some embodiments, the anti-adhesion structure comprises one or more outgassing substances.

[0115] In some embodiments, the present disclosure provides a method for forming a microelectromechanical system (MEMS) device. The method includes forming a sensing electrode on an interlayer dielectric (ILD) structure, wherein the ILD structure is disposed on a first semiconductor substrate. Forming an anti-stiction structure on the ILD structure, wherein the anti-stiction structure is a silicon-based semiconductor. Bonding a second semiconductor substrate to a third semiconductor substrate. Forming a movable body in the second semiconductor substrate. After bonding the second semiconductor substrate and the third semiconductor substrate together, bonding the second and third semiconductor substrates to the first semiconductor substrate.

[0116] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art will understand that they can easily use this disclosure as a basis for designing or modifying other processes and structures to perform the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also recognize that these equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications thereto without departing from the spirit and scope of the present disclosure.

Claims

1. A micro-electromechanical system device comprising: a dielectric structure disposed over the first semiconductor substrate, wherein the dielectric structure at least partially defines a cavity; a second semiconductor substrate disposed over the dielectric structure and comprising a movable body, wherein opposing sidewalls of the movable body are disposed between opposing sidewalls of the cavity; an anti-adhesion structure disposed between the movable body and the dielectric structure, wherein the anti-adhesion structure is a first silicon-based semiconductor; as well as an electrode disposed between the movable body and the dielectric structure, wherein the electrode is a second silicon-based semiconductor, and wherein both the electrode and the anti-stiction structure are amorphous solids, wherein the anti-adhesion structure comprises one or more outgassing substances, The micro-electromechanical system device further comprises: an interconnect structure disposed in the dielectric structure, wherein the anti-stiction structure is electrically coupled to the interconnect structure; as well as An outgassing structure is disposed in the dielectric structure, and the outgassing structure is not electrically coupled to the interconnect structure. 2 . The MEMS device of claim 1 , wherein the anti-stiction structure is electrically coupled to an uppermost via of the interconnect structure. 3 . The MEMS device of claim 1 , wherein the anti-stiction structure has a resistivity between about 0.5 milliohm-cm and about 100 ohm-cm. 4 . The MEMS device of claim 1 , wherein the one or more outgassing species comprises argon, hydrogen, nitrogen, or a combination thereof. The MEMS device according to claim 1 , wherein an uppermost surface of the anti-adhesion structure is disposed lower than an uppermost surface of the electrode. The MEMS device according to claim 1 , wherein an uppermost surface of the anti-adhesion structure is arranged to be higher than an uppermost surface of the electrode. The MEMS device according to claim 1 , wherein an uppermost surface of the anti-stiction structure is coplanar with an uppermost surface of the electrode. 8 . The MEMS device of claim 1 , wherein the anti-stiction structure is partially embedded below the uppermost surface of the dielectric structure and partially disposed above the uppermost surface of the dielectric structure. 9 . The MEMS device according to claim 8 , wherein the anti-stiction structure has a first upper surface and a second upper surface, the first upper surface is arranged lower than the uppermost surface of the dielectric structure, and the second upper surface is arranged higher than the uppermost surface of the dielectric structure.

10. A micro-electromechanical system device comprising: A sensing circuit is provided on the first semiconductor substrate; an interlayer dielectric structure disposed above the first semiconductor substrate and the sensing circuit, wherein the interlayer dielectric structure at least partially defines a cavity; an interconnect structure embedded in the interlayer dielectric structure, wherein the interconnect structure is electrically coupled to the sensing circuit; a second semiconductor substrate disposed over the interlayer dielectric structure and comprising a movable body, wherein opposite sidewalls of the movable body are disposed between opposite sidewalls of the cavity; an anti-stiction structure disposed between the movable body and the interlayer dielectric structure, wherein the anti-stiction structure is a silicon-based semiconductor and is electrically coupled to the interconnect structure, and wherein the sensing circuit is configured to measure a change in capacitive coupling between the movable body and the anti-stiction structure, wherein the anti-stiction structure includes one or more outgassing substances; as well as a silicon-based outgassing structure disposed between the movable body and the interlayer dielectric structure, wherein the silicon-based outgassing structure is spaced apart from the anti-adhesion structure; The silicon-based outgassing structure is not electrically coupled to the interconnect structure.

11. The MEMS device according to claim 10, wherein the anti-stiction structure has a first upper surface and a second upper surface, the first upper surface is arranged lower than the uppermost surface of the interlayer dielectric structure, and the second upper surface is arranged higher than the uppermost surface of the interlayer dielectric structure.

12. The MEMS device according to claim 10, wherein the uppermost surface of the silicon-based outgassing structure is coplanar with the uppermost surface of the interlayer dielectric structure, and wherein the uppermost surface of the anti-stiction structure is arranged to be higher than the uppermost surface of the silicon-based outgassing structure.

13. The MEMS device according to claim 10, further comprising: An electrode is provided between the movable body and the interlayer dielectric structure, wherein the electrode is provided between the anti-stiction structure and the interlayer dielectric structure in a vertical direction and contacts both the interlayer dielectric structure and the anti-stiction structure. The MEMS device according to claim 13 , wherein a yield stress of the anti-stiction structure is greater than a yield stress of the electrode. 15 . The MEMS device according to claim 14 , wherein opposite sidewalls of the anti-stiction structure are substantially aligned with opposite sidewalls of the electrode, respectively.

16. The MEMS device according to claim 15, wherein: The electrode has a first chemical composition; and The anti-stick structure has a second chemical composition different from the first chemical composition. The MEMS device according to claim 10 , wherein the anti-stiction structure is an amorphous solid.

18. A micro-electromechanical system device comprising: A sensing circuit is provided on the first semiconductor substrate; an interlayer dielectric structure disposed above the first semiconductor substrate and the sensing circuit, wherein the interlayer dielectric structure at least partially defines a cavity; an interconnect structure embedded in the interlayer dielectric structure, wherein the interconnect structure is electrically coupled to the sensing circuit; a second semiconductor substrate bonded to the first semiconductor substrate, wherein the second semiconductor substrate is bonded to the first semiconductor substrate via a bonding structure, the bonding structure being in contact with both the interlayer dielectric structure and the second semiconductor substrate, wherein the bonding structure at least partially defines the cavity, and wherein the second semiconductor substrate includes a movable body disposed between opposing sidewalls of the cavity; an electrode disposed between the interlayer dielectric structure and the movable body, wherein the electrode is electrically coupled to the interconnect structure and comprises a silicon-based semiconductor; a first anti-stiction structure disposed between the interlayer dielectric structure and the movable body, wherein the first anti-stiction structure is spaced apart from the electrode, and wherein the first anti-stiction structure comprises the silicon-based semiconductor and one or more outgassing substances, wherein the first anti-stiction structure is partially embedded in the interlayer dielectric structure and partially disposed on the interlayer dielectric structure; as well as a second anti-sticking structure disposed between the interlayer dielectric structure and the movable body, wherein the second anti-sticking structure is spaced apart from the electrode, wherein the electrode is disposed laterally between the first anti-sticking structure and the second anti-sticking structure, wherein the second anti-sticking structure comprises the silicon-based semiconductor and the one or more outgassing substances, The micro-electromechanical system device further comprises: An outgas structure is disposed in the interlayer dielectric structure, and the outgas structure is not electrically coupled to the interconnect structure.

19. The MEMS device according to claim 18, wherein the first anti-stiction structure has a first upper surface and a second upper surface, the first upper surface is configured to be lower than the uppermost surface of the interlayer dielectric structure, and the second upper surface is configured to be higher than the uppermost surface of the interlayer dielectric structure. 20 . The MEMS device of claim 18 , wherein the first anti-stiction structure and the second anti-stiction structure are amorphous solids.

21. A method of forming a micro-electromechanical system device, the method comprising: forming a sensing electrode on an interlayer dielectric structure, wherein the interlayer dielectric structure is disposed on a first semiconductor substrate; forming an anti-stiction structure on the interlayer dielectric structure, wherein the anti-stiction structure is a silicon-based semiconductor, and wherein the anti-stiction structure comprises one or more outgassing substances; bonding the second semiconductor substrate to the third semiconductor substrate; forming a movable body in the second semiconductor substrate; as well as After bonding the second semiconductor substrate and the third semiconductor substrate together, bonding both the second semiconductor substrate and the third semiconductor substrate to the first semiconductor substrate, The micro-electromechanical system device further comprises: an interconnect structure disposed in the interlayer dielectric structure, wherein the anti-stiction structure is electrically coupled to the interconnect structure; as well as An outgas structure is disposed in the interlayer dielectric structure, and the outgas structure is not electrically coupled to the interconnect structure.

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