Pressure sensor and manufacture method thereof

• US 9,598,275 B2
• Filed: 01/14/2015
• Issued: 03/21/2017
• Est. Priority Date: 06/25/2014
• Status: Active Grant

• Current Assignee: Miramems Sensing Technology Co., Ltd
• Original Assignee: Miramems Sensing Technology Co., Ltd
• Inventors: Chien, Yu-Hao, Tseng, Li-Tien
• Primary Examiner(s): Mondt, Johannes P
• Application Number:
  US14/596,967
• Publication Number:
  US 20150375994A1
• Time in Patent Office: 797 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2203/033 Trenches
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 2207/094 Feed-through, via
• CPC Class Codes: B81B 7/0041 maintaining a controlled atmosphere with techniques not provided for in B81B7/0038
• 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 1/00293 maintaining a controlled atmosphere with processes not provided for in B81C1/00285
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts
• CPC Class Codes: B81C 2203/0172 Seals
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A pressure sensor using the MEMS device comprises an airtight ring surrounding a chamber defined by the first substrate and the second substrate. The airtight ring extends from the upper surface of the second substrate to the surface between the first substrate and the second substrate and further breaks out the surface. The pressure sensor utilizes the airtight ring to retain the airtightness of the chamber. The manufacture method of the pressure sensor is also disclosed.

Claims

1. A manufacture method of a pressure sensor, comprising:

providing a first substrate comprising a metal layer, wherein the metal layer is partially exposed on a surface of the first substrate to form a first circuit, a second circuit and a conductive contact;

providing a second substrate comprising a first surface and a second surface;

mounting the second substrate to the surface of the first substrate in which the first surface of the second substrate faces to the first substrate to define a first chamber and a second chamber, wherein the first circuit is configured in the first chamber, and the second circuit is configured in the second chamber;

forming a MEMS element and a reference element on the second substrate, wherein the MEMS element corresponds to the first circuit, and the reference element corresponds to the second circuit;

forming a through slot surrounding the first chamber and penetrating the second surface of the second substrate and an interface between the first substrate and the second substrate;

forming a via penetrating the second surface of the second substrate and the surface between the first substrate and the second substrate to expose the conductive contact;

filling the through slot with a filler so that an airtight ring is formed, wherein the airtight ring breaks out the interface between the first substrate and the second substrate; and

filling the via with a conductive material to electrically connect the second substrate and the conductive contact.

2. The manufacture method of the pressure sensor according to claim 1, wherein the through slot exposes the metal layer of the first substrate.

3. The manufacture method of the pressure sensor according to claim 1, wherein the step of forming the through slot and the step of forming the via are completed simultaneously in the same semiconductor process.

4. The manufacture method of the pressure sensor according to claim 1, wherein the step of filling the filler and the step of filling the conductive material are completed simultaneously in the same semiconductor process.

5. The manufacture method of the pressure sensor according to claim 1, wherein the first substrate comprises a second airtight ring corresponding to the first airtight ring and connecting to the metal layer and another lower metal layer.

6. The manufacture method of the pressure sensor according to claim 1, further comprising:

forming at least one trench on the surface of the first substrate or the first surface of the second substrate to define at least one micro channel after mounting the second substrate and the first substrate, wherein the micro channel connects the first chamber and the through slot; and

introducing an anti-sticking material through the micro channel after forming the through slot to form an anti-sticking layer on the inner surface of the first chamber.

7. The manufacture method of the pressure sensor according to claim 6, wherein the micro channel comprises a bent portion bending to horizontal or vertical direction.

8. The manufacture method of the pressure sensor according to claim 6, wherein the micro channel comprises a dam for reducing the inner diameter of the micro channel.

9. The manufacture method of the pressure sensor according to claim 1, further comprising:

forming a notch on side of the first surface or side of the second surface of the second substrate for thinning the MEMS element.

10. The manufacture method of the pressure sensor according to claim 1, further comprising:

forming an anti-moving bump on the surface of the first substrate corresponding to the MEMS element.

11. The manufacture method of the pressure sensor according to claim 1, wherein the via and the through slot are integrated together.

12. The manufacture method of the pressure sensor according to claim 1, wherein the conductive material in the via and the second substrate form an ohmic contact, wherein the ohmic contact region is made of at least one of silicon, aluminum-copper alloy, titanium nitride and tungsten.

13. The manufacture method of the pressure sensor according to claim 1, wherein the first substrate comprises a complementary metal oxide semiconductor substrate.

14. The manufacture method of the pressure sensor according to claim 1, further comprising:

providing a third substrate having a notch region and a plurality of bracket structure; and

connecting the third substrate to the surface of the first substrate through the bracket structure to place the second substrate in the notch region.

15. The manufacture method of the pressure sensor according to claim 14, wherein the third substrate comprises a channel configured on a terminal of the bracket structure.