Integrated CMOS and MEMS devices with air dieletrics

• US 9,365,412 B2
• Filed: 04/03/2013
• Issued: 06/14/2016
• Est. Priority Date: 06/23/2009
• Status: Active Grant

• Current Assignee: Movella Incorporated (Movella Holdings, Inc.)
• Original Assignee: mCube, Inc.
• Inventors: Yang, Xiao (Charles)
• Primary Examiner(s): Weiss, Howard
• Application Number:
  US13/855,988
• Publication Number:
  US 20160060102A1
• Time in Patent Office: 1,168 Days
• Field of Search: 257/66, 257/288, 257/69, 257/415, 257/522, 257/E23.145, 257/E21.573, 257/E21.632, 257/782, 438/50, 438/422, 438/619, 438/411, 438/199, 438/319, 438/455, 438/456
• US Class Current: 1/1
• CPC Class Codes: B81B 2207/094 Feed-through, via
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81B 7/008 MEMS characterised by an electronic circuit specially adapted for controlling or driving the same B81B7/0087 takes precedence; arrangements for starting, regulating, braking, or otherwise controlling an actuator H02N; control arrangements or circuits for visual indicators G09G3/00
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 1/00246 Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate
• CPC Class Codes: H01L 21/8221 Three dimensional integrated circuits stacked in different levels
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 27/092 complementary MIS field-effect transistors
• CPC Class Codes: H01L 29/0649 Dielectric regions, e.g. SiO2 regions, air gaps
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

A monolithically integrated CMOS and MEMS device. The device includes a first semiconductor substrate having a first surface region and one or more CMOS IC devices on a CMOS IC device region overlying the first surface region. The CMOS IC device region can also have a CMOS surface region. A bonding material can be provided overlying the CMOS surface region to form an interface by which a second semiconductor substrate can be joined to the CMOS surface region. The second semiconductor substrate has a second surface region coupled to the CMOS surface region by bonding the second surface region to the bonding material. The second semiconductor substrate includes one or more first air dielectric regions. One or more free standing MEMS structures can be formed within one or more portions of the processed first substrate.

Claims

1. A monolithic integrated CMOS and MEMS device, the device comprising:

a thickness of a first semiconductor substrate having a first top surface region and a first bottom surface region;

one or more CMOS integrated circuit (IC) devices provided on a CMOS integrated circuit (IC) device region coupled to the first bottom surface region, the CMOS IC device region having a CMOS surface region, wherein the one or more CMOS IC devices includes a plurality of transistors configured in an upside-down orientation;

a bonding material coupled to the CMOS surface region;

a second semiconductor substrate having a second top surface region and a second bottom surface region, the second top surface region coupled to the CMOS surface region by bonding the second top surface region to the bonding material, the second semiconductor substrate comprising one or more first air dielectric regions spatially configured towards the second top surface region;

one or more free standing MEMS structures overlying and adjacent to one or more portions of the first top surface region of the thickness of the first semiconductor substrate.

2. The device of claim 1 wherein the first semiconductor substrate is selected from a group consisting of:

a buried oxide (BOX) layer overlying a silicon substrate, an epitaxial (EPI) layer overlying a silicon substrate, an amorphous silicon substrate, a single crystal silicon substrate, and a polycrystalline silicon substrate.

3. The device of claim 1 wherein each of the plurality of transistors has source and drain regions above a gate region, and the one or more free standing MEMS structures are disposed closer to the source and drain regions than to the gate region.

4. The device of claim 1 further comprising one or more via structures within one or more portions of the first semiconductor substrate, the one or more via structures extending from one or more portions of the CMOS integrated circuit device region to a vicinity of the thickness of the first semiconductor substrate.

5. The device of claim 1 further comprising an enclosure layer overlying the one or more free standing MEMS devices, the enclosure layer having one or more openings.

6. The device of claim 5 wherein the enclosure layer comprises a titanium material, the titanium material being activated as a getter layer.

7. The device of claim 5 further comprising:

an open region provided between the one or more free standing MEMS structures and the enclosure layer; and

an encapsulating layer provided overlying the enclosure layer to substantially seal the one or more free standing MEMS structures to form a predetermined environment within the open region.

8. The device of claim 7 wherein the predetermine environment comprises an inert gas at a determined pressure.

9. The device of claim 1 further comprising one or more bond pad openings to expose one or more bond pads coupled to the CMOS device layer.

10. The device of claim 1 further comprising an enclosure housing the one or more free standing MEMS structures, the enclosure configured overlying the first outer region of the thickness of the first semiconductor substrate, the enclosure having an upper cover region.

11. A monolithic integrated CMOS and MEMS device, the device comprising:

a thickness of a first semiconductor substrate having a first top surface region, a first bottom surface region, and one or more first air dielectric regions;

one or more CMOS integrated circuit (IC) devices provided on a CMOS integrated circuit (IC) device region coupled to the first bottom surface region, the CMOS IC device region having a CMOS surface region, wherein the one or more CMOS IC devices includes a plurality of transistors configured in a flipped orientation;

a bonding material coupled to the CMOS surface region;

a second semiconductor substrate having a second top surface region and a second bottom surface region, the second top surface region coupled to the CMOS surface region by bonding the second surface region to the bonding material, the second semiconductor substrate comprising one or more second air dielectric regions spatially configured towards the second top surface region;

one or more free standing MEMS structures overlying one or more portions of the first top surface region of the thickness of the first semiconductor substrate.

12. The device of claim 11 wherein the first semiconductor substrate is selected from a group consisting of:

a buried oxide (BOX) layer overlying a silicon substrate, an epitaxial (EPI) layer overlying a silicon substrate.

13. The device of claim 11 wherein the bonding material is a chemical mechanical planarization (CMP) processed bonding material or a top oxide material.

14. The device of claim 11 further comprising an enclosure layer overlying the one or more free standing MEMS devices, the enclosure layer having one or more openings, wherein the enclosure layer comprises a titanium material, the titanium material being activated as a getter layer.

15. The device of claim 14 further comprising:

an open region provided between the one or more free standing MEMS structures and the enclosure layer; and

an encapsulating layer provided overlying the enclosure layer to substantially seal the one or more free standing MEMS structures to form a predetermined environment within the open region, wherein the predetermined environment comprises an inert gas at a determined pressure.

16. The device of claim 15 wherein the encapsulating layer is selected from a metal layer, a spin on glass, a spray on glass, amorphous silicon, a dielectric layer, or any combination of these layers.

17. A monolithic integrated CMOS and MEMS device, the device comprising:

a thickness of a first semiconductor substrate having a first top surface region and a first bottom surface region;

one or more CMOS integrated circuit (IC) devices provided on a CMOS integrated circuit (IC) device region coupled to the first bottom surface region, the CMOS IC device region having a CMOS surface region, wherein the one or more CMOS IC devices includes a plurality of transistors configured in an upside-down orientation and a plurality of interconnect layers below the plurality of transistors;

a bonding material coupled to the CMOS surface region;

a second semiconductor substrate having a second top surface region and a second bottom surface region, the second top surface region coupled to the CMOS surface region by bonding the second top surface region to the bonding material, the second semiconductor substrate comprising one or more first air dielectric regions spatially configured towards the second top surface region;

a bonding structure coupled to a top interconnect layer in the CMOS IC device region at the CMOS surface region;

one or more free standing MEMS structures overlying and adjacent to one or more portions of the first top surface region of the thickness of the first semiconductor substrate.

18. The device of claim 17 wherein the first semiconductor substrate is a buried oxide (BOX) layer overlying a silicon substrate or an epitaxial (EPI) layer overlying a silicon substrate.

19. The device of claim 17 wherein the bonding structure comprises a portion extending through the second semiconductor substrate.

20. The device of claim 17 wherein the bonding structure comprises a portion extending through the first semiconductor substrate.