Mechanisms for forming micro-electro mechanical system device

• US 10,160,640 B2
• Filed: 10/20/2016
• Issued: 12/25/2018
• Est. Priority Date: 11/19/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Cheng, Chun-Wen, Chu, Chia-Hua
• Primary Examiner(s): Yi, Changhyun
• Application Number:
  US15/299,161
• Publication Number:
  US 20170036909A1
• Time in Patent Office: 796 Days
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• 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 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence
• 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 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 1/00293 maintaining a controlled atmosphere with processes not provided for in B81C1/00285

Abstract

A method for forming a micro-electro mechanical system (MEMS) device is provided. The method includes bonding a semiconductor substrate with a carrier substrate through a dielectric layer and patterning the semiconductor substrate into multiple elements. The method also includes partially removing the dielectric layer to release some of the elements such that the released elements become one (or more) first movable element and one (or more) second movable element. The method further includes bonding a cap substrate with the semiconductor substrate to form a first closed chamber containing the first movable element and a second closed chamber containing the second movable element. In addition, the method includes opening the second closed chamber and sealing the second closed chamber after vacuumizing the second closed chamber such that the second closed chamber has a reduced pressure smaller than that of the first closed chamber.

Claims

1. A method for forming a micro-electro mechanical system (MEMS) device, comprising:

forming a dielectric layer over a semiconductor substrate;

bonding the dielectric layer with a carrier substrate;

patterning the semiconductor substrate into a plurality of elements;

partially removing the dielectric layer to release some of the elements such that the released elements become at least one first movable element and at least one second movable element;

bonding a cap substrate with the semiconductor substrate to form a first closed chamber and a second closed chamber between the semiconductor substrate and the cap substrate;

bonding a CMOS substrate with the carrier substrate;

removing a portion of the cap substrate to open the second closed chamber; and

vacuumizing and sealing the second closed chamber after the second closed chamber is open such that the second closed chamber has a second pressure after the vacuumizing and sealing of the second closed chamber, wherein a first pressure of the first closed chamber is higher than the second pressure, and the first movable element and the second movable element are in the first closed chamber and the second closed chamber, respectively.

2. The method for forming a MEMS device as claimed in claim 1, further comprising:

removing a portion of the cap substrate to open the first closed chamber; and

bonding a second cap substrate with the cap substrate to seal the first closed chamber such that the first closed chamber has the first pressure.

3. The method for forming a MEMS device as claimed in claim 1, further comprising annealing the dielectric layer before the CMOS substrate is bonded with the carrier substrate.

4. The method for forming a MEMS device as claimed in claim 1, further comprising thinning the carrier substrate before the CMOS substrate is bonded with the carrier substrate.

5. The method for forming a MEMS device as claimed in claim 1, further comprising:

forming an opening penetrating through the cap substrate, the dielectric layer, and the semiconductor substrate;

filling a blocking layer in the opening; and

forming a conductive plug penetrating through the carrier substrate and the blocking layer to electrically contact with a conductive pad of the CMOS substrate.

6. The method for forming a MEMS device as claimed in claim 5, wherein the blocking layer filling the opening surrounds the first closed chamber and the second closed chamber.

7. The method for forming a MEMS device as claimed in claim 5 wherein the blocking layer is formed before bonding the CMOS substrate with the carrier substrate.

8. The method for forming a MEMS device as claimed in claim 7, further comprising thinning the carrier substrate before the conductive plug is formed.

9. The method for forming a MEMS device as claimed in claim 5, further comprising forming a conductive pad on the conductive plug.

10. The method for forming a MEMS device as claimed in claim 9, wherein the sealing of the second closed chamber is achieved using a sealing element, and the sealing element and the conductive pad are formed simultaneously.

11. A method for forming a micro-electro mechanical system (MEMS) device, comprising:

bonding a semiconductor substrate with a carrier substrate through a dielectric layer;

patterning the semiconductor substrate into a plurality of elements;

partially removing the dielectric layer to release some of the elements such that the released elements become at least one first movable element and at least one second movable element;

bonding a cap substrate with the semiconductor substrate to form a first closed chamber containing the first movable element and a second closed chamber containing the second movable element;

opening the second closed chamber; and

after opening the second closed chamber, sealing the second closed chamber after vacuumizing the second closed chamber such that the second closed chamber has a reduced pressure smaller than a pressure of the first closed chamber.

12. The method for forming a MEMS device as claimed in claim 11, wherein pressures of the first closed chamber and the second closed chamber are substantially the same before opening the second closed chamber.

13. The method for forming a MEMS device as claimed in claim 11, further comprising bonding a second cap substrate over the cap substrate.

14. The method for forming a MEMS device as claimed in claim 13, further comprising partially removing the cap substrate to open the first closed chamber, wherein the first closed chamber is sealed again after the second cap substrate is bonded over the cap substrate.

15. The method for forming a MEMS device as claimed in claim 13, further comprising forming a surrounding blocking layer surrounding the first closed chamber and the second closed chamber.

16. The method for forming a MEMS device as claimed in claim 15, further comprising forming a conductive plug penetrating through the surrounding blocking layer.

17. A method for forming a micro-electro mechanical system (MEMS) device, comprising:

bonding a semiconductor substrate with a carrier substrate;

patterning the semiconductor substrate into a plurality of elements to form at least one first movable element and at least one second movable element;

bonding a cap substrate with the semiconductor substrate to form a first closed chamber containing the first movable element and a second closed chamber containing the second movable element; and

opening the second closed chamber and then sealing the second closed chamber such that the second closed chamber has a pressure lower than a pressure of the first closed chamber.

18. The method for forming a MEMS device as claimed in claim 17, wherein pressures of the first closed chamber and the second closed chamber are substantially the same before opening the second closed chamber and then sealing the second closed chamber.

19. The method for forming a MEMS device as claimed in claim 17, further comprising bonding a second cap substrate over the cap substrate such that the cap substrate is between the second cap substrate and the semiconductor substrate.

20. The method for forming a MEMS device as claimed in claim 19, further comprising partially removing the cap substrate to open the first closed chamber, wherein the first closed chamber is sealed again after the second cap substrate is bonded over the cap substrate.