Microelectromechanical systems (mems) stopper structure for stiction improvement

Patent metadata

Field	Value
Publication number	US-2016167945-A1
Application number	US-201414570282-A
Country	US
Kind code	A1
Filing date	Dec 15, 2014
Priority date	Dec 15, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A microelectromechanical systems (MEMS) structure having a stopper integrated with a MEMS substrate is provided. A first substrate has a dielectric layer arranged over the first substrate. The dielectric layer includes a device opening. A second substrate is arranged over and bonded to the first substrate through the dielectric layer. The second substrate includes a deflectable element arranged over the device opening. A stopper is integrated with the second substrate and protrudes from the deflectable element over the device opening. A method for manufacturing the MEMS structure is also provided.

First claim

What is claimed is:

1 . A microelectromechanical systems (MEMS) structure comprising:
a first substrate having a dielectric layer arranged over the first substrate, wherein the dielectric layer includes a device opening; a second substrate arranged over and bonded to the first substrate through the dielectric layer, the second substrate including a deflectable element arranged over the device opening; and a stopper integrated with the second substrate and protruding from the deflectable element over the device opening.

2 . The MEMS structure according to claim 1 , wherein the second substrate, the deflectable element, and the stopper include silicon.

3 . The MEMS structure according to claim 1 , further including:
a third substrate including a second device opening, wherein the third substrate is arranged over and bonded to the second substrate with the second device opening over the deflectable element.

4 . The MEMS structure according to claim 1 , wherein the stopper is arranged within a recess in the second substrate overlying the device opening.

5 . The MEMS structure according to claim 1 , further including:
first bond pads arranged in the dielectric layer around the device opening; through silicon vias (TSVs) extending through the second substrate to the first bond pads; and second bond pads arranged over the second substrate and electrically coupled to the first bond pads through the TSVs.

6 . The MEMS structure according to claim 1 , further including:
a sensing electrode arranged in the device opening and capacitively coupled to the deflectable element.

7 . The MEMS structure according to claim 6 , wherein the sensing electrode is arranged directly below the stopper.

8 . The MEMS structure according to claim 1 , wherein a footprint of the stopper is elliptical.

9 . The MEMS structure according to claim 1 , further including:
a second stopper arranged in the device opening below the stopper and extending towards the deflectable element.

10 . A method for manufacturing a microelectromechanical systems (MEMS) structure, the method comprising:
providing a first substrate having a dielectric layer arranged over the first substrate, wherein the dielectric layer includes a device opening; providing a second substrate; forming a stopper integrated with the second substrate; bonding the second substrate to the first substrate through the dielectric layer, wherein the stopper protrudes towards the first substrate from over the device opening; and forming a deflectable element in the second substrate over the device opening and the stopper.

11 . The method according to claim 10 , further including:
recessing a central region of the second substrate around a stopper region to form the stopper.

12 . The method according to claim 10 , wherein the second substrate is silicon, and wherein the method further includes:
forming the stopper of silicon, wherein the second substrate and the stopper are a continuous piece of silicon.

13 . The method according to claim 10 , further including:
providing a third substrate having a second device opening; and bonding the third substrate over the second substrate with the second device opening over the deflectable element.

14 . The method according to claim 10 , further including:
providing first bond pads arranged in the dielectric layer around the device opening; forming through silicon vias (TSVs) extending through the second substrate to the first bond pads; and forming second bond pads over the second substrate and electrically coupled to the first bond pads through the TSVs.

15 . The method according to claim 10 , further including:
providing a sensing electrode in the device opening; and forming the stopper at a position laterally offset from the sensing electrode.

16 . The method according to claim 10 , further including:
forming the stopper with a rectangular footprint.

17 . The method according to claim 10 , further including:
forming a second stopper in the device opening below the stopper and extending towards the deflectable element.

18 . The method according to claim 10 , further including:
forming a spring in the second substrate, the spring supporting the deflectable element over the device opening.

19 . The method according to claim 10 , further including:
forming one of a MEMS microphone, a MEMS pressure sensor, and a MEMS motion sensor in the second substrate.

20 . A microelectromechanical systems (MEMS) structure comprising:
an integrated circuit (IC) including a first substrate and a dielectric layer arranged over the first substrate, wherein the dielectric layer includes a device opening; a MEMS device including a second substrate arranged over and bonded to the first substrate through the dielectric layer, the second substrate including a deflectable element arranged over the device opening; and a stopper integrated with the second substrate and protruding from the deflectable element over the device opening, wherein the stopper and the second substrate are silicon.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chang Kai-Fung
• Tsai Lien-Yao
• Leu Len-Yi

Classifications

• H10D48/50

  Devices controlled by mechanical forces, e.g. pressure · CPC title

• B81B3/001 Primary

  Structures having a reduced contact area, e.g. with bumps or with a textured surface · CPC title

• B81C1/00325

  for reducing stress inside of the package structure · CPC title

• B81B3/0051 Primary

  For defining the movement, i.e. structures that guide or limit the movement of an element (mechanical arrangements for preventing or damping vibration or shock H01H3/60) · CPC title