Miniaturized Implantable Sensor Platform having Multiple Devices and Sub-Chips

• US 20140353791A1
• Filed: 08/18/2014
• Published: 12/04/2014
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Optoelectronics Systems Consulting Incorporated
• Original Assignee: Optoelectronics Systems Consulting Incorporated
• Inventors: Jain, Faquir, Papadimitrakopoulos, Fotios
• Granted Patent: US 9,204,839 B2
• Time in Patent Office: Days
• US Class Current: 257/434
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 31/02005 for device characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

This invention describes a hermetically sealed package which can be implanted in the body. The package comprise of stacked substrates where surface of one substrate hosts biosensors which are exposed to body fluids to monitor concentrations of substances selected from analytes, metabolites, and proteins, and body physiological parameters. The structure protects from body fluids devices that interface with the biosensor electrodes for electronic data processing, powering, and wireless communication. Biosensor electrodes are electrically connected to various electronic, optoelectronic, MEM devices using novel partial silicon vias (PSVs) that prevents leakage of body fluids. Various devices are located on different substrates which are stacked to save surface area. One of the substrate forms the cover plate which permits light for powering as well as sending receiving coded data including the analyte levels.

Claims

1. A device, comprising:

a layered structure in Si configured to form Si Vias for hermetically sealed electrical connectivity between two sets of devices, which are realized on at least two Si layers of a Si-on-insulator substrate,

wherein the Si-on-insulator substrate is comprised of a first Si layer and a second Si layer separated by a first SiO2 layer serving as an insulator,

wherein the first Si layer has on it a deposited second insulator film selected from SiO2, SiN, HfO2, and

wherein Si pillars are created in the first Si layer by etching regions surrounding the Si pillars, wherein the Si pillars are supported by a first oxide layer and the second Si layer,

wherein the exposed surface of the Si pillars and surrounding surface of the first Si layer are deposited with thin oxide layer selected from SiO2, HfO2, Si3N4, SiON, and

wherein etched regions are filled with material selected from undoped amorphous Si, SiO2, HfO2, wherein the Si pillars have a top side and a bottom side, the bottom side interfaces with first oxide,

wherein the second Si layer and the first oxide layer under the Si pillars are etched to expose the bottom side of the Si pillar in the first Si layer,

wherein the exposed Si surface of bottom side of pillars are deposited with a metal providing Ohmic contact, wherein the metal is selected from gold, arsenic doped gold, aluminum, Pt, Pd, TiN, and TaN, and

wherein the Ohmic contact is deposited with a metal pad selected from a biocompatible non-corrosive metal selected from Au, Pt, and Pd, and

wherein the second Si layer side opposite to the first SiO2 layer is deposited with a passivation insulator layer selected from SiO2, HfO2, SiN, and Al2O3, and

wherein the passivation insulator layer is patterned to expose second Si layer which is deposited with electrodes to form biosensors, electronic circuits, optoelectronic circuits, ultrasonic transducers and other devices that operate electrically,

wherein the top side of the Si pillars are deposited with a metal providing Ohmic contact, and wherein the metal is selected from gold, arsenic doped gold, aluminum, Pt, Pd, TiN, and TaN, and

wherein the Ohmic contact is deposited with a metal pad selected from Au, Pt, Pd, and wherein the metal pads on top side of Si pillars are connected to devices selected from electronic, photonic, optoelectronic, and micro-electro-mechanical realized in first Si layer.

2. The device of claim 1, wherein Si vias are formed for hermetically sealing electrical connectivity between two sets of devices, which are realized on at least three Si layers consisting of two Si layers comprised of Si-on-insulator substrate,

wherein the Si-on-insulator substrate comprise of a first Si layer and a second Si layer separated by first SiO2 layer severing as an insulator,

wherein the first Si layer has on it a deposited second insulator film selected from SiO2, SiN, and HfO2, and

wherein the second Si layer is deposited with a third insulator layer selected from SiO2, SiN, and HfO2, and

wherein the third insulator is deposited with a third Si layer selected from a poly-Si, and a poly Ge thin film, wherein the third Si layer is protected with a passivation insulator layer,

wherein the passivation insulator layer is selected from SiO2, HfO2, SiN, and Al2O3,

wherein the bottom side of the Si pillar in first Si layer is contacted by patterning and etching passivation insulator layer, third Si layer, third insulator layer, and second Si layer and first insulator layer,

wherein the exposed Si surface of bottom side of pillars are deposited with a metal providing an Ohmic contact, wherein the metal is selected from gold, arsenic doped gold, aluminum, Pt, Pd, TiN, and TaN, and

wherein the Ohmic contact is deposited with a metal pad selected from biocompatible non-corrosive metals selected from Au, Pt, and Pd, and

wherein the passivation insulator layer is patterned to expose third Si layer which is deposited with electrodes to form biosensors, electronic circuits, optoelectronic circuits, ultrasonic transducers and other devices that operate electrically,

wherein the top side of the Si pillars are deposited with a metal providing Ohmic contact, the metal is selected from gold, arsenic doped gold, aluminum, Pt, Pd, TiN, and TaN,

wherein the Ohmic contact is deposited with a metal pad selected from Au, Pt, and Pd, and the metal pads on top side of Si pillars are connected to devices selected from electronic, photonic, optoelectronic, and micro-electro-mechanical realized in the first Si layer.

3. The device of claim 1, wherein the Si vias are configured to interconnect the biosensors and the electronic devices.

4. A hermetically sealed structure, comprising:

at least two stacks of substrates, wherein the structure permits exposure of biosensor surfaces on which electrodes are realized to monitor concentrations of substances selected from analytes, metabolites, and proteins, and body physiological parameters,

wherein the structure protects from body fluids devices that interface with the biosensor electrodes for electronic data processing, powering, and wireless communication, and

wherein the devices are located on any of the substrates forming a stack,

wherein biosensor electrodes are electrically, connected to the devices using partial silicon vias,

wherein substrates forming the stack are selected from Si, Si-on-Insulator (SOI) and Silicon-on-sapphire, silicon-on-quartz,

wherein the Si-on-insulator (SOI) substrate include a first Si layer and a second Si layer separated by a first SiO2 layer severing as an insulator,

wherein the Si-on-sapphire (SOS) substrate includes a Si layer on a sapphire substrate,

wherein the SOS substrate serves as a cover plate permitting light energy to be used to power the solar cells, located on other substrates forming the multi-stack structure,

wherein the SOS substrate cover plate permitting coded light signals to communicate with receiver photodiodes located on the Si film on the SOS or other substrates,

wherein the cover plate substrate having a gold film on the Si thin film forming an eutectic,

wherein the thin film having a perimeter fence formed by gold bump layer,

wherein the substrate hosting the biosensor electrodes includes on its other face a perimeter gold fence formed on the Si—

Au eutectic thin film,

wherein the biosensor hosting substrate and the cover plate substrate heremetically seal the vertical stack.

5. The hermetically sealed structure of claim 4, further comprising

a Si frame wafer with perimeter fence matching the top cover wafer and bottom biosensor substrate,

wherein the stack forms a sealed structure, and

wherein the Si frame substrate being hollow in the middle provides space to bond pads of bottom and top substrates.