Substrate-level assembly for an integrated device, manufacturing process thereof and related integrated device

Abstract

A substrate-level assembly having a device substrate of semiconductor material with a top face and housing a first integrated device, including a buried cavity formed within the device substrate, and with a membrane suspended over the buried cavity in the proximity of the top face. A capping substrate is coupled to the device substrate above the top face so as to cover the first integrated device in such a manner that a first empty space is provided above the membrane. Electrical-contact elements electrically connect the integrated device with the outside of the substrate-level assembly. In one embodiment, the device substrate integrates at least a further integrated device provided with a respective membrane, and a further empty space, fluidly isolated from the first empty space, is provided over the respective membrane of the further integrated device.

The invention claimed is: 
     
       1. A substrate-level An assembly, comprising:
 a device substrate of semiconductor material, having a top face and housing a first integrated device provided with an active area adjacent to the top face that includes a first buried cavity in the device substrate and a first membrane suspended above the first buried cavity, the device substrate further including a second membrane; 
 a capping substrate cap coupled to the device substrate above the top face so as to cover the first integrated device in such a manner that and covering an upper portion of the device substrate and forming a first empty space is provided in a position corresponding to the active area between an inner surface of the cap and the first membrane of the device substrate and forming a second empty space between an inner surface of the cap and a surface of the second membrane, the first and second empty spaces being isolated from each other; and 
 an access duct in the cap that provides fluid connectivity between the first empty space and an environment outside of the assembly; and 
 electrical-contact elements for electrical connection of the first integrated device device substrate to a location outside of the substrate-level assembly. 
 
     
     
       2. The assembly of  claim 1 , wherein the first integrated device is provided with a buried cavity formed within the device substrate and a membrane suspended over the buried cavity at the active area; the first empty space being provided in a position corresponding to the membrane electrical-contact elements include at least one of contact pads located on the top surface of the device substrate or on a bottom surface of the device substrate. 
     
     
       3. The assembly of claim  1 , wherein an access duct is provided within the capping substrate, the access duct being fluidly connected to the first empty space and to the outside of the substrate-level assembly 2 wherein the electrical-contact elements include through vias that are coupled to a respective contact pad on the bottom surface of the device substrate. 
     
     
       4. The assembly of  claim 1 , wherein the capping substrate has a first sensor cavity above the active area of the first integrated device, the first sensor cavity forming at least in part the first empty space; in particular, the first sensor cavity having empty space has a depth in the range of 10 μm and 400 μm. 
     
     
       5. The assembly of  claim 1 , further comprising a surface of the cap bonded to a surface of the device substrate at a bonding region arranged between the device substrate and the capping substrate to ensure joining thereof, and placed in contact with the top face in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device; the first empty space being delimited, at least in part, by the bonding region. 
     
     
       6. The assembly of  claim 5 , wherein the capping substrate is flat and not patterned and the bonding region has a thickness between 6 μm and 100 μm to entirely define a thickness of the first empty space. 
     
     
       7. The assembly of  claim 5 , wherein the capping substrate includes one between cap is formed from at least one of the following materials: semiconductor material, glass, ceramic, and polymeric material; and wherein the bonding region includes glass frit or a metal or polymeric material. 
     
     
       8. The assembly of  claim 5 , wherein at least one of the capping substrate cap and bonding region is made of a conductive material configured to provide an electrostatic shield for the first integrated device; the first integrated device comprising, and wherein the first membrane is part of a microphone. 
     
     
       9. The assembly of claim  2 , wherein the electrical-contact elements comprise at least one of through vias made through the device substrate and electrical-connection pads formed on a portion of the top face of the device substrate not covered by the capping substrate; and 1 wherein the first integrated device further comprises a buried cavity formed within the device substrate, a membrane suspended over the buried cavity, and device substrate includes transduction elements configured to transform a deformation of the first membrane into electrical signals, the electrical-contact elements being connected coupled to the transduction elements. 
     
     
       10. The assembly of  claim 1 , wherein the first integrated device further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity; and a first access duct is provided within the capping substrate and fluidly connected to the first empty space and to the outside of the substrate-level assembly; and further comprising a second access duct is provided within the device substrate in fluid communication with the first buried cavity of the integrated device and with the environment outside of the substrate-level assembly. 
     
     
       11. The assembly of  claim 1 , wherein a first access duct and a plurality of further access ducts are provided within the capping substrate, and fluidly connected to the cap includes a plurality of access ducts that provide fluid connectivity between the first empty space and to the environment outside of the substrate-level assembly; the first and further access ducts being at least one of: different size and separated by a different inter-spacing. 
     
     
       12. The assembly of  claim 1 , wherein the device substrate houses at least a further integrated device provided with a respective active area; and wherein a further empty space is provided in a position corresponding to the respective active area of the further integrated device; the further empty space being fluidly isolated with respect to the first empty space. 
     
     
       13. The assembly of claim  12  1, wherein the capping substrate has at least one further sensor cavity set above the respective active area of the further integrated device, and forming, at least in part, the further empty space; the first empty space and further empty space separated in a fluid-tight manner, at least in part, by a separation portion of the capping substrate placed between the first empty space and the further empty space the second empty space is not in fluid communication with the environment outside the assembly. 
     
     
       14. The assembly of claim  12  1, further comprising a bonding region placed between the device substrate and the capping substrate, and in contact with the top face of the device substrate in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device and the respective active area of the further integrated device; the first empty space and the further empty space being delimited, at least in part, by the bonding region wherein the device substrate includes a second buried cavity and the second membrane is suspended above the second buried cavity. 
     
     
       15. The assembly of claim  12  1, wherein the first integrated device further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity, and the further integrated device comprising a respective buried cavity formed within the device substrate and a respective membrane suspended over the respective buried cavity; and wherein the first integrated device is a pressure sensor, and the further integrated device is an inertial sensor, the inertial sensor comprising an inertial mass arranged on the respective membrane within the further empty space the second membrane is an inertial sensor. 
     
     
       16. The assembly of  claim 15 , wherein the inertial sensor includes an inertial mass arranged on the second membrane and the inertial mass includes metal material, deposited directly on top of the respective membrane; the metal material chosen from the group comprising silver, tin, copper, lead, and gold, and having a density greater than 7000 kg/m 3 . 
     
     
       17. The assembly of claim  12  1, wherein the first integrated device comprises membrane, the first empty space, and the first buried cavity are part of a pressure sensor, and the further integrated device comprises second membrane, second empty space, and a second buried cavity are part of a reference pressure sensor for the pressure sensor. 
     
     
       18. The assembly of  claim 1 , wherein the first integrated device further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity; the first integrated device comprising membrane, the first empty space, and the first buried cavity are part of a microphone sensor having a back-chamber separated from the first buried cavity by a sensing diaphragm configured to move as a result of the pressure exerted thereon by sound waves reaching the first buried cavity. 
     
     
       19. The assembly of claim  18  1, wherein the first integrated device further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity; the first integrated device comprising membrane, the first empty space, and the first buried cavity form a gas sensor and the first membrane including includes a detection material configured to allow detecting the presence of a gaseous material; the membrane being thermally decoupled from the device substrate. 
     
     
       20. The assembly of claim  1  12, wherein the capping substrate includes a layer grown on the device substrate, in particular by electroplating or epitaxial steps; the capping substrate being integral to the device substrate second membrane includes an accelerometer. 
     
     
       21. An electronic device, comprising:
 a substrate-levelan assembly that includes:
 a device substrate of semiconductor material, having a top face and housing a including first integrated device provided with an active area adjacent to the top face and second sensor regions;   a capping substrate cap coupled to the device substrate above the top face so as to cover the first integrated device and second sensor regions in such a manner that a first empty space cavity is provided in a position corresponding to the active area above the first sensor region and a second cavity is provided above the second sensor region, the first cavity being separate from the second cavity; and   electrical-contact elements for electrical connection of to the first integrated device and second sensor regions extending outside of the substrate-level assembly first and second cavities; and   
 a package encasing and mechanically protecting the substrate-level assembly; wherein the package comprises that includes:
 a base body mechanically supporting the substrate-level assembly, and 
 aan insulative coating region configured to coat laterallymaterial that is located on lateral sides of the substrate-level assembly. 
 
 
     
     
       22. The device of  claim 21 , wherein an access duct is provided within the capping substrate cap, the access duct being fluidly connected to the first empty space and to the an environment outside of substrate-level the assembly, wherein the coating region leaves the access duct uncovered and accessible from the outside:
 a top surface of the capping substrate cap defining part of a first outer face of the package, and 
 the access duct. 
 
     
     
       23. The device of  claim 21 , wherein the package is of an LGA, SO, QFN or BGA type, and has contact pads carried by a surface of the base body, which is not in contact with the substrate-level assembly and that defines a second outer face of the package. 
     
     
       24. The device of  claim 21 , further comprising a circuit die electrically coupled to the substrate-level assembly and encased by the package: wherein the device substrate and circuit die are mechanically coupled to the base body through a respective adhesion layer, and arranged side by side wherein the first sensor region includes a buried cavity formed in the device substrate and a membrane suspended above the buried cavity. 
     
     
       25. The device of claim  21  24, further comprising a circuit die electrically coupled to the substrate-level assembly and encased by the package; the circuit die being mechanically coupled to the base body, and the device substrate being mechanically coupled to the circuit die in a stacked manner wherein the cap includes an access duct that places the first cavity is fluid communication with an environment outside of the assembly. 
     
     
       26. The device of  claim 21 , further comprising an access duct extending through the base body and reaching the substrate-level assembly at a surface thereof, opposite to the top face. 
     
     
       27. The device of  claim 21 , wherein the electronic device comprises one of: a tire-pressure monitoring system, a blood-pressure monitoring system, an ink-ejection system, and a mobile phone. 
     
     
       28. A process for manufacturing a substrate-level an assembly, comprising:
 providing a device substrate of semiconductor material, having a top face; 
 forming a first integrated device within sensor region in a top face of the device substrate, and with an active area adjacent to the top facethe first sensor region including a buried cavity and a membrane suspended above the buried cavity; 
 coupling a capping substrate cap to the device substrate above the top face so as to cover the first integrated device, the coupling comprising forming and form a first empty space in a position corresponding to the active area above the membrane, the cap including a plurality of access ducts that places the first empty space in fluid communication with an environment outside of the assembly, the plurality of access ducts being of different sizes or a different inter-spacing being provided therebetween or a combination of different sizes and different inter-spacing; and 
 forming electrical-contact elements from the top face of the device substrate to a bottom face of the device substrate for electrical connection of the first integrated device with the outside of the substrate-level assembly. 
 
     
     
       29. The process of  claim 28 , wherein forming a first integrated device further comprises forming a buried cavity within the device substrate and a membrane suspended over the buried cavity, the first empty space formed in a position corresponding to the membrane further comprising forming a second sensor region in the top face of the device substrate, wherein coupling the cap to the device substrate further comprises forming a second empty space above the second sensor region. 
     
     
       30. The process of claim  28 , further comprising forming in the capping substrate access duct fluidly connected to the first empty space and to the outside of the substrate-level assembly 29, wherein the first empty space is fluidly isolated from the second empty space. 
     
     
       31. The process of  claim 28 , wherein forming a first empty space comprises forming in the capping substrate a sensor cavity above the active area of the first integrated device the first sensor region includes a pressure sensor component and the second sensor region includes an accelerometer component or a reference pressure sensor component. 
     
     
       32. The process of  claim 28 , wherein the mechanically coupling the cap to the device comprises: forming a bonding region between the device substrate and the capping substrate cap and in contact with the top face of the device substrate in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device; an active area of the first sensor region and joining the device substrate and the capping substrate cap via the bonding region; and wherein the first empty space is delimited, at least in part, by the bonding region. 
     
     
       33. The process of  claim 28 , wherein forming a first integrated device further comprises forming a buried cavity within the device substrate, and a membrane suspended over the buried cavity, and forming the first sensor region includes transducer elements configured to transform into electrical signals a deformation of the membrane, and forming electrical-contact elements comprises: forming at least one between through vias through the device substrate, and forming electrical-connection pads on a portion of the top face of the device substrate not covered by the capping substrate; and connecting the through vias or the electrical-connection pads to the transduction elements into electrical signals. 
     
     
       34. The process of  claim 28 , wherein forming a first integrated device further comprises forming a buried cavity within the device substrate, and a membrane suspended over the buried cavity; further comprising forming in the capping substrate a first access duct, fluidly connected to the first empty space and to the outside of the substrate-level assembly, and further comprising forming in the device substrate a second access duct in fluid communication with the buried cavity of the integrated device first sensor region and with the environment outside of the substrate-level assembly. 
     
     
       35. The process of  claim 28 , further comprising forming a first access duct and a plurality of further access ducts within the capping substrate and fluidly connected to the first empty space and to the outside of the substrate-level assembly; in particular, the first and further access ducts being of different size or a different inter-spacing being provided therebetween or a combination of different size and different inter-spacing. 
     
     
       36. The process of  claim 28 , further comprising:
 forming in the device substrate at least one further integrated device provided with a respective second sensor region having an active area; and  
 the coupling further comprising forming a further second empty space in a position corresponding to the respective active area of the further integrated device; second sensor region, the further second empty space being fluidly isolated from the first empty space. 
 
     
     
       37. The process of  claim 36 , wherein forming a further second empty space comprises forming at least a further one second sensor cavity in the capping substrate cap, over the respective active area of the further integrated device second sensor region; the forming at least a further one second sensor cavity comprising separating the first empty space and the further second empty space via a separation portion of the capping substrate cap. 
     
     
       38. The process of  claim 36 , wherein the coupling the cap to the device substrate comprises forming a bonding region set between the device substrate and the capping substrate cap and in contact with the top face in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device and the respective active area of the further integrated device; the first empty space and the further empty space being delimited, at least in part, by the bonding region the membrane of the first sensor region. 
     
     
       39. The process of claim  36 , wherein forming a first integrated device 29 wherein forming the second sensor region comprises forming a buried cavity within the device substrate and a membrane suspended over the buried cavity, and forming a further integrated device comprises forming a respective buried cavity within the device substrate and a respective membrane suspended over the respective buried cavity; and wherein forming a first integrated device comprises forming a pressure sensor, and forming at least one further integrated device comprises the process further comprising forming an inertial sensor that comprises forming an inertial mass on the respective membrane and within the further empty space of the second sensor region. 
     
     
       40. The process of  claim 39 , wherein forming an the inertial mass comprises depositing directly on top of the respective membrane metal material chosen in the group comprising silver, tin, copper, lead, and gold, and having a density higher than 7000 kg/m 3 . 
     
     
       41. The process of claim  36  29, wherein forming a first integrated device the first sensor region comprises forming a portion of a pressure sensor, and forming at least one further integrated device a second sensor region comprises forming a portion of a reference pressure sensor for the pressure sensor. 
     
     
       42. The process of  claim 28 , wherein forming a first integrated device the first sensor region comprises forming a portion of a microphone sensor that includes a buried cavity within the device substrate, a membrane suspended over the buried cavity, and a back-chamber separated from the buried cavity by a sensing diaphragm configured to move as a result of pressure exerted thereon by sound waves reaching the buried cavity. 
     
     
       43. The process of  claim 28 , wherein forming a first integrated device the first sensor region comprises forming a portion of a gas sensor, and in particular a buried cavity within the device substrate, and a membrane suspended over the buried cavity; forming the membrane comprising forming of the gas sensor including a detection material configured to allow detecting the presence of a gaseous material, the membrane being thermally decoupled from the device substrate. 
     
     
       44. The process of  claim 28 , wherein coupling the capping substrate cap comprises growing a layer of material on the device substrate by electroplating or epitaxial steps; the capping substrate cap being integral to the device substrate. 
     
     
       45. A process for manufacturing an electronic device, comprising:
 forming a substrate-level an assembly, the forming including:
 providing a device substrate of semiconductor material, having a top face; 
 forming a first integrated device within the device substrate and with an active area adjacent to the top face buried cavity in a device substrate of semiconductor material, a first membrane being located above the buried cavity; 
 forming a second buried cavity in the device substrate, a second membrane being located above the second buried cavity;  
 coupling a capping substrate cap to the device substrate above the top face so as to cover the first integrated device and second membranes, the coupling comprising forming a first empty space in a position corresponding to the active area and a second empty space, the first empty space being located over the first membrane, the second empty space being located over the second membrane, the first empty space being fluidly isolated from the second empty space; and 
 forming electrical-contact elements in the device substrate for electrical connection of the first integrated device with the outside of the substrate-level assembly; and 
 
 encasing the substrate-level assembly in a package, for coating and mechanically protecting the substrate-level assembly; 
 wherein the encasing comprises providing a base body to support the substrate-level assembly, and coating laterally the substrate-level sides of the assembly with a an insulative coating region material. 
 
     
     
       46. The process of  claim 45 , further comprising providing an access duct within the capping substrate cap, the access duct being fluidly connected to connecting the first empty space and to the an environment outside of the substrate-level assembly, wherein the coating region material is configured to leave the access duct uncovered and accessible from the outside:
 a top surface of the capping substrate cap defining part of a first outer face of the package, and 
 the access duct. 
 
     
     
       47. The process of  claim 45 , comprising forming contact pads at a surface of the base body, which is not in contact with the substrate-level assembly and defines a second outer face of the package. 
     
     
       48. The process of  claim 45 , further comprising electrically coupling a circuit die to the substrate-level assembly within the package; and wherein the encasing further comprises mechanically coupling, arranged side by side, the device substrate and circuit die to the base body through a respective adhesion layer an inertial sensor located on top of the second membrane, the inertial sensor being configured to sense an acceleration. 
     
     
       49. The process of  claim 45 , further comprising electrically coupling a circuit die to the substrate-level assembly within the package; and wherein the encasing further comprises mechanically coupling the circuit die to the base body, and said mechanically coupling the device substrate to the circuit die in a stacked manner wherein the base body includes through vias that electrically couple the electrical-contact elements of the device substrate outside of the package. 
     
     
       50. The process of  claim 45 , further comprising forming an access duct extending through the base body and reaching the substrate-level assembly at a surface thereof, opposite to the top face forming a third buried cavity in the device substrate, a third membrane being located above the third buried cavity. 
     
     
       51. An assembly comprising:
 an article, and 
 a base substrate having a first surface and a second surface;  
 a sensor assembly adapted to monitor at least one condition of the article, the sensor assembly comprising: 
 a first device substrate of semiconductor material, having a top face and housing including a first integrated device provided with sensor region having an active area adjacent to the top face; 
 a second device substrate of semiconductor material having a first surface and including an integrated circuit, the first device substrate being located on the first substrate of the second device substrate, the integrated circuit being electrically coupled to the first sensor region;  
 a capping substrate cap coupled to the first device substrate above the top face so as to cover the first integrated device in such a manner sensor region so that a first empty space is provided in a position corresponding to above the active area; and 
 electrical-contact elements extending from the first surface to the second surface of the base substrate for electrical connection of the first integrated device sensor region and the integrated circuit outside of the substrate-level assembly. 
 
     
     
       52. The assembly of  claim 51 , wherein the first integrated device is provided with sensor region includes a buried cavity formed within the first device substrate and a membrane suspended over the buried cavity at the active area; the first empty space being provided in a position corresponding to the membrane. 
     
     
       53. The assembly of  claim 51 , wherein a first access duct is provided within the capping substrate cap, the first access duct being fluidly connected to the first empty space and to the an environment outside of the substrate-level assembly. 
     
     
       54. The assembly of  claim 51 , wherein the capping substrate cap has a first sensor cavity above the active area of the first integrated device sensor region, the first sensor cavity forming at least in part the first empty space; the first sensor cavity having a depth in the range of 10 μm and 400 μm. 
     
     
       55. The assembly of  claim 51 , further comprising a bonding region arranged between the first device substrate and the capping substrate cap to ensure joining thereof, and placed in contact with the top face in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device; the first empty space being delimited, at least in part, by the bonding region. 
     
     
       56. The assembly of  claim 55 , wherein the capping substrate cap is a flat and not patterned substrate and the bonding region has a thickness between 6 and 100 μm to entirely define that defines a thickness of the first empty space. 
     
     
       57. The assembly of  claim 52 , wherein the electrical-contact elements comprise at least one through via made through the device substrate; and electrical-connection pads formed on a portion of the top face of the device substrate not covered by the capping substrate; and wherein the first integrated device further comprises sensor region includes a buried cavity formed within the device substrate and a membrane suspended over the buried cavity, and transduction elements configured to transform a deformation of the membrane into electrical signals, the electrical-contact elements being connected to the transduction elements. 
     
     
       58. The assembly of  claim 51 , wherein the first integrated device sensor region further comprises a buried cavity formed within the first device substrate and a membrane suspended over the buried cavity; and the cap includes a first access duct is provided within the capping substrate and is fluidly connected to the that places the first empty space and to the in fluid communication with an environment outside of the substrate-level assembly and a second access duct is provided within the device substrate in fluid communication with the buried cavity of the integrated device and with the outside of the substrate-level assembly. 
     
     
       59. The assembly of  claim 51 , wherein a first access duct and a plurality of further second access ducts are provided within the capping substrate cap, and fluidly connected to the first empty space and to the an environment outside of the substrate-level assembly; the first and further access ducts being at least one of different size and separated by a different inter-spacing. 
     
     
       60. The assembly of  claim 51 , wherein the device substrate houses at least a further integrated device provided with a respective active area; and wherein a further empty space is provided in a position corresponding to the respective active area of the further integrated device; the further empty space being fluidly isolated with respect to the first empty space the first and second access ducts are at least one of different size and separated by a different inter-spacing. 
     
     
       61. The assembly of  claim 60 , wherein the capping substrate has at least one further sensor cavity set above the respective active area of the further integrated device, and forming, at least in part, the further empty space; the first empty space and further empty space being separated in a fluid-tight manner, at least in part, by a separation portion of the capping substrate placed between the first empty space and the further empty space a second device substrate includes an access duct. 
     
     
       62. The assembly of  claim 60 , further comprising a bonding region placed between the first device substrate and the capping substrate cap, and in contact with the top face of the first device substrate in such a manner as to surround, without being superimposed thereon, the active area of the first integrated device and the respective active area of the further integrated device; the first empty space and the further empty space being delimited, at least in part, by the bonding region sensor region. 
     
     
       63. The assembly of  claim 58 , wherein the first integrated device further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity, and the further integrated device comprising a respective buried cavity formed within the device substrate and a respective membrane suspended over the respective buried cavity; and wherein the first integrated device is a pressure sensor, and the further integrated device is an inertial sensor, the inertial sensor comprising an inertial mass arranged on the respective membrane within the further empty space further comprising a coating material that is located on a portion of the first surface of the base substrate. 
     
     
       64. The assembly of  claim 60 , wherein the first integrated device comprises sensor region is a portion of a pressure sensor, and the further integrated device comprises a reference pressure sensor for the pressure sensor. 
     
     
       65. The assembly of  claim 51 , wherein the first integrated device sensor region further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity; the first integrated device comprising sensor region forming part of a microphone sensor having a back-chamber separated from the buried cavity by a sensing diaphragm configured to move as a result of the pressure exerted thereon by sound waves reaching the buried cavity. 
     
     
       66. The assembly of  claim 65 , wherein the first integrated device sensor region further comprises a buried cavity formed within the device substrate and a membrane suspended over the buried cavity; the first integrated device comprising sensor region forming a portion of a gas sensor and the membrane including a detection material configured to allow detecting the presence of a gaseous material; the membrane being thermally decoupled from the device substrate. 
     
     
       67. The assembly of  claim 51 , wherein the capping substrate includes a layer grown on the device substrate, in particular by electroplating or epitaxial steps; the capping substrate being integral to the device substrate second device substrate includes an access duct that extends from the first surface to a second surface, the access duct placing a portion of the first sensor region in fluid communication with an environment outside of the assembly.