Abstract: A semiconductor device is formed such that a semiconductor substrate of the device has a non-uniform thickness. A cavity is etched at a selected side of the semiconductor substrate, and the selected side is then fusion bonded to another substrate, such as a carrier substrate. After fusion bonding, the side of the semiconductor substrate opposite the selected side is ground to a defined thickness. Accordingly, the semiconductor substrate has a uniform thickness except in the area of the cavity, where the substrate is thinner. Devices that benefit from a thinner substrate, such as an accelerometer, can be formed over the cavity.

Abstract: An assembly (220) includes a MEMS die (222) and an integrated circuit (IC) die (224) attached to a substrate (226). The MEMS die (222) includes a MEMS device (237) formed on a substrate (242). A packaging process (264) entails forming the MEMS device (237) on the substrate (242) and removing a material portion of the substrate (237) surrounding the device (237) to form a cantilevered substrate platform (246) suspended above the substrate (226) at which the MEMS device (237) resides. The MEMS die (222) is electrically interconnected with the IC die (224). A plug element (314) can be positioned overlying the platform (246). Molding compound (32) is applied to encapsulate the die (222), the IC die (224), and substrate (226). Following encapsulation, the plug element (314) can be removed, and a cap (236) can be coupled to the substrate (242) overlying an active region (244) of the MEMS device (237).

Abstract: A semiconductor device is formed such that a semiconductor substrate of the device has a non-uniform thickness. A cavity is etched at a selected side of the semiconductor substrate, and the selected side is then fusion bonded to another substrate, such as a carrier substrate. After fusion bonding, the side of the semiconductor substrate opposite the selected side is ground to a defined thickness. Accordingly, the semiconductor substrate has a uniform thickness except in the area of the cavity, where the substrate is thinner. Devices that benefit from a thinner substrate, such as an accelerometer, can be formed over the cavity.

Abstract: A method for forming a semiconductor device includes providing a substrate having a first major surface and a second major surface, removing a first portion of the substrate to form a cavity at the first major surface of the substrate, bonding the first major surface of the substrate to a carrier substrate after forming the cavity, and reducing a thickness of the substrate. The method further includes forming a first accelerometer device at the second major surface such that at least a portion of the first accelerometer device is over the cavity and forming a second accelerometer device at the second major surface such that the second accelerometer device is not disposed over the cavity.

Abstract: A semiconductor die (20) includes a substrate (30) and microelectronic devices (22, 26) located at a surface (32) of the substrate (30). A cap (34) is coupled to the substrate (30), and the microelectronic device (22) is positioned in the cavity (24). An outgassing material structure (36) is located within a cavity (24) between the cap (34) and the substrate (30). The outgassing material structure (36) releases trapped gas (37) to increase the pressure within the cavity (24) from an initial pressure level (96) to a second pressure level (94). The cap (34) may include another cavity (28) containing another microelectronic device (26). A getter material (42) may be located within the cavity (28). The getter material (42) is activated to absorb residual gas (46) in the cavity (28) and decrease the pressure within the cavity (28) from the initial pressure level (96) to a third pressure level (92).

Abstract: A MEMS is attached to a bonding wafer in part by forming a support layer over the MEMS. A first eutectic layer is formed over the support layer. The eutectic layer is patterned into segments to relieve stress. A second eutectic layer is formed over the bonding wafer. A eutectic bond is formed with the segments and the second eutectic layer to attach the bonding wafer to the MEMS.

Abstract: A semiconductor device is formed such that a semiconductor substrate of the device has a non-uniform thickness. A cavity is etched at a selected side of the semiconductor substrate, and the selected side is then fusion bonded to another substrate, such as a carrier substrate. After fusion bonding, the side of the semiconductor substrate opposite the selected side is ground to a defined thickness. Accordingly, the semiconductor substrate has a uniform thickness except in the area of the cavity, where the substrate is thinner. Devices that benefit from a thinner substrate, such as an accelerometer, can be formed over the cavity.

Abstract: A disclosed semiconductor fabrication process includes forming a first bonding structure on a first surface of a cap wafer, forming a second bonding structure on a first surface of a device wafer, and forming a device structure on the device wafer. One or more eutectic flow containment structures are formed on the cap wafer, the device wafer, or both. The flow containment structures may include flow containment micro-cavities (FCMCs) and flow containment micro-levee (FCMLs). The FCMLs may be elongated ridges overlying the first surface of the device wafer and extending substantially parallel to the bonding structure. The FCMLs may include interior FCMLs lying within a perimeter of the bonding structure, exterior FCMLs lying outside of the bonding structure perimeter, or both. When the two wafers are bonded, the FCMLs and FCMCs confine flow of the eutectic material to the region of the bonding structure.

Abstract: A device (20, 90) includes sensors (28, 30) that sense different physical stimuli. A pressure sensor (28) includes a reference element (44) and a sense element (52), and an inertial sensor (30) includes a movable element (54). Fabrication (110) entails forming (112) a first substrate structure (22, 92) having a cavity (36, 100), forming a second substrate structure (24) to include the sensors (28, 30), and coupling (128) the substrate structures so that the first sensor (28) is aligned with the cavity (36, 100) and the second sensor (30) is laterally spaced apart from the first sensor (28). Forming the second structure (24) includes forming (118) the sense element (52) from a material layer (124) of the second structure (24) and following coupling (128) of the substrate structures, concurrently forming (132) the reference element (44) and the movable element (54) in a wafer substrate (122) of the second structure (24).

Abstract: A device structure is made using a first conductive layer over a first wafer. An isolated conductive region is formed in the first conductive layer surrounded by a first opening in the conductive layer. A second wafer has a first insulating layer and a conductive substrate, wherein the conductive substrate has a first major surface adjacent to the first insulating layer. The insulating layer is attached to the isolated conductive region. The conductive substrate is thinned to form a second conductive layer. A second opening is formed through the second conductive layer and the first insulating layer to the isolated conductive region. The second opening is filled with a conductive plug wherein the conductive plug contacts the isolated conductive region. The second conductive region is etched to form a movable finger over the isolated conductive region. A portion of the insulating layer under the movable finger is removed.

Abstract: A MEMS is attached to a bonding wafer in part by forming a support layer over the MEMS. A first eutectic layer is formed over the support layer. The eutectic layer is patterned into segments to relieve stress. A second eutectic layer is formed over the bonding wafer. A eutectic bond is formed with the segments and the second eutectic layer to attach the bonding wafer to the MEMS.

Abstract: A microelectromechanical systems (MEMS) pressure sensor device (20, 62) includes a substrate structure (22, 64) having a cavity (32, 68) formed therein and a substrate structure (24) having a reference element (36) formed therein. A sense element (44) is interposed between the substrate structures (22, 24) and is spaced apart from the reference element (36). The sense element (44) is exposed to an external environment (48) via one of the cavity (68) and a plurality of openings (38) formed in the reference element (36). The sense element (44) is movable relative to the reference element (36) in response to a pressure stimulus (54) from the environment (48). Fabrication methodology (76) entails forming (78) the substrate structure (22, 64) having the cavity (32, 68), fabricating (84) the substrate structure (24) including the sense element (44), coupling (92) the substrate structures, and subsequently forming (96) the reference element (36) in the substrate structure (24).

Abstract: A device (20, 90) includes sensors (28, 30) that sense different physical stimuli. A pressure sensor (28) includes a reference element (44) and a sense element (52), and an inertial sensor (30) includes a movable element (54). Fabrication (110) entails forming (112) a first substrate structure (22, 92) having a cavity (36, 100), forming a second substrate structure (24) to include the sensors (28, 30), and coupling (128) the substrate structures so that the first sensor (28) is aligned with the cavity (36, 100) and the second sensor (30) is laterally spaced apart from the first sensor (28). Forming the second structure (24) includes forming (118) the sense element (52) from a material layer (124) of the second structure (24) and following coupling (128) of the substrate structures, concurrently forming (132) the reference element (44) and the movable element (54) in a wafer substrate (122) of the second structure (24).

Abstract: An assembly (220) includes a MEMS die (222) and an integrated circuit (IC) die (224) attached to a substrate (226). The MEMS die (222) includes a MEMS device (237) formed on a substrate (242). A packaging process (264) entails forming the MEMS device (237) on the substrate (242) and removing a material portion of the substrate (237) surrounding the device (237) to form a cantilevered substrate platform (246) suspended above the substrate (226) at which the MEMS device (237) resides. The MEMS die (222) is electrically interconnected with the IC die (224). A plug element (314) can be positioned overlying the platform (246). Molding compound (32) is applied to encapsulate the die (222), the IC die (224), and substrate (226). Following encapsulation, the plug element (314) can be removed, and a cap (236) can be coupled to the substrate (242) overlying an active region (244) of the MEMS device (237).

Abstract: A device (20, 90) includes sensors (28, 30) that sense different physical stimuli. A pressure sensor (28) includes a reference element (44) and a sense element (52), and an inertial sensor (30) includes a movable element (54). Fabrication (110) entails forming (112) a first substrate structure (22, 92) having a cavity (36, 100), forming a second substrate structure (24) to include the sensors (28, 30), and coupling (128) the substrate structures so that the first sensor (28) is aligned with the cavity (36, 100) and the second sensor (30) is laterally spaced apart from the first sensor (28). Forming the second structure (24) includes forming (118) the sense element (52) from a material layer (124) of the second structure (24) and following coupling (128) of the substrate structures, concurrently forming (132) the reference element (44) and the movable element (54) in a wafer substrate (122) of the second structure (24).

Abstract: A method (50) for producing a layered wafer structure (24) having anti-stiction bumps (22) entails producing the anti-stiction bumps (22) in a surface (32) of a substrate (26) or, alternatively, in a surface (48) of a substrate (28). The method (50) further entails coupling the substrates (26, 28) with an insulator layer (30) interposed between the substrates (26, 28). A MEMS structure (20) having a movable element (34) is formed in the substrate (28) and openings (78) defining the movable element (34) extend through the substrate (28). A portion of the insulator layer (30) is removed via the openings (78) to release the movable element (34). The anti-stiction bumps (22) limit stiction between the movable element (34) and the underlying substrate (26).

Abstract: A device (20, 90) includes sensors (28, 30) that sense different physical stimuli. A pressure sensor (28) includes a reference element (44) and a sense element (52), and an inertial sensor (30) includes a movable element (54). Fabrication (110) entails forming (112) a first substrate structure (22, 92) having a cavity (36, 100), forming a second substrate structure (24) to include the sensors (28, 30), and coupling (128) the substrate structures so that the first sensor (28) is aligned with the cavity (36, 100) and the second sensor (30) is laterally spaced apart from the first sensor (28). Forming the second structure (24) includes forming (118) the sense element (52) from a material layer (124) of the second structure (24) and following coupling (128) of the substrate structures, concurrently forming (132) the reference element (44) and the movable element (54) in a wafer substrate (122) of the second structure (24).

Abstract: A microelectromechanical systems (MEMS) pressure sensor device (20, 62) includes a substrate structure (22, 64) having a cavity (32, 68) formed therein and a substrate structure (24) having a reference element (36) formed therein. A sense element (44) is interposed between the substrate structures (22, 24) and is spaced apart from the reference element (36). The sense element (44) is exposed to an external environment (48) via one of the cavity (68) and a plurality of openings (38) formed in the reference element (36). The sense element (44) is movable relative to the reference element (36) in response to a pressure stimulus (54) from the environment (48). Fabrication methodology (76) entails forming (78) the substrate structure (22, 64) having the cavity (32, 68), fabricating (84) the substrate structure (24) including the sense element (44), coupling (92) the substrate structures, and subsequently forming (96) the reference element (36) in the substrate structure (24).

Abstract: A device structure is made using a first conductive layer over a first wafer. An isolated conductive region is formed in the first conductive layer surrounded by a first opening in the conductive layer. A second wafer has a first insulating layer and a conductive substrate, wherein the conductive substrate has a first major surface adjacent to the first insulating layer. The insulating layer is attached to the isolated conductive region. The conductive substrate is thinned to form a second conductive layer. A second opening is formed through the second conductive layer and the first insulating layer to the isolated conductive region. The second opening is filled with a conductive plug wherein the conductive plug contacts the isolated conductive region. The second conductive region is etched to form a movable finger over the isolated conductive region. A portion of the insulating layer under the movable finger is removed.

Abstract: A method for making a MEMS structure comprises patterning recesses in a dielectric layer overlying a substrate, each recess being disposed between adjacent mesas of dielectric material. A conformal layer of semiconductor material is formed overlying the recesses and mesas. The conformal layer is chemical mechanically polished to form a chemical mechanical polished surface, wherein the chemical mechanical polishing is sufficient to create dished portions of semiconductor material within the plurality of recesses. Each dished portion has a depth proximate a central portion thereof that is less than a thickness of the semiconductor material proximate an outer portion thereof. A semiconductor wafer is then bonded to the chemical mechanical polished surface. The bonded semiconductor wafer is patterned with openings according to the requirements of a desired MEMS transducer. Lastly, the MEMS transducer is released.