MEMS capping method

Patent metadata

Field	Value
Publication number	US-9731960-B2
Application number	US-201615018740-A
Country	US
Kind code	B2
Filing date	Feb 8, 2016
Priority date	Apr 21, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A semiconductor device includes a substrate structure. The substrate structure includes a protruding engagement member having an inner periphery defining a groove and an outer periphery, an oxide layer on the protruding engagement member, and a bonding material layer on the oxide layer. The semiconductor device also includes a micro-electromechanical system (MEMS) substrate having a bonging pad. The bonding pad of the MEMS substrate is bonded to the bonding material layer of the substrate structure.

First claim

What is claimed is:

1. A MEMS device produced by a method comprising:
providing a substrate with a front surface and a back surface;
forming a protruding engagement member on the front surface of the substrate, the protruding engagement member having an inner periphery defining a groove;
forming a first trench having a first depth along an outer periphery of the protruding engagement member;
forming a patterned mask layer on the protruding engagement member covering the engagement member including the groove and exposing a portion of the first trench;
etching the exposed portion of the first trench using the patterned mask layer as a mask to form a second trench having a second depth;
removing the patterned mask layer;
providing a MEMS substrate;
cleaning the MEMS substrate using a diluted hydrofluoric acid (DHF) including HF, H 2 O 2 and H 2 O having a concentration ratio of HF:H 2 O 2 :H 2 O=0.1-1.5:1:5; and
bonding the substrate with the MEMS substrate to form the MEMS device.

2. The MEMS device of claim 1 , further comprising:
forming a bonding material layer on a surface of the protruding engagement member;
forming a bonding pad on the MEMS substrate; and
bonding the bonding pad to the bonding material layer to seal the MEMS device.

3. The MEMS device of claim 1 , wherein etching the exposed portion of the first trench comprises a deep reactive ion etching process using a silicon hexafluoride (SF6) gas, with a RF power to form a high ionization, under a pressure in the range from 20 mTorr to 8 Torr, the power of 600 W, 13.5 MHz, and a DC bias voltage is in the range from 500 V to 1000 V.

4. A semiconductor device, comprising:
a substrate structure comprising:
a protruding engagement member having an inner periphery defining a groove and an outer periphery;
an oxide layer on the protruding engagement member; and
a bonding material layer on the oxide layer;

a micro-electromechanical system (MEMS) substrate having a bonding pad,
wherein the bonding pad of the MEMS substrate is bonded to the bonding material layer of the substrate structure.

5. The semiconductor device of claim 4 , wherein the MEMS substrate comprises at least one MEMS device, and the bonding pad is configured to seal the MEMS device.

6. The semiconductor device of claim 4 , wherein the bonding material layer has a thickness greater than a thickness of the oxide layer.

7. The semiconductor device of claim 4 , wherein the bonding material layer comprises germanium.

8. The semiconductor device of claim 4 , wherein the oxide layer has a width equal to a width of the protruding engagement member.

9. The semiconductor device of claim 4 , wherein the bonding material layer has a width smaller than a width of the protruding engagement member.

10. The semiconductor device of claim 4 , wherein the substrate structure further comprises a metal layer on sidewalls and on the outer periphery of the protruding engagement member.

11. The semiconductor device of claim 4 , wherein the metal layer comprises titanium.

12. The semiconductor device of claim 4 , wherein the protruding engagement member has a height greater than a spacing between opposite sides of the inner periphery.

13. A MEMS device produced by a method comprising:
providing a substrate with a front surface and a back surface;
forming a protruding engagement member on the front surface of the substrate, the protruding engagement member having an inner periphery defining a groove;
forming a first trench having a first depth along an outer periphery of the protruding engagement member;
forming a patterned mask layer on the protruding engagement member covering the engagement member including the groove and exposing a portion of the first trench;
etching the exposed portion of the first trench using the patterned mask layer as a mask to form a second trench having a second depth;
removing the patterned mask layer;
providing a MEMS substrate; and
bonding the substrate with the MEMS substrate to form the MEMS device,
wherein etching the exposed portion of the first trench comprises a deep reactive ion etching process using a silicon hexafluoride (SF6) gas, with a RF power to form a high ionization, under a pressure in the range from 20 mTorr to 8 Torr, the power of 600 W, 13.5 MHz, and a DC bias voltage is in the range from 500 V to 1000 V.

Assignees

• Semiconductor Mfg Int Shanghai Corp

Inventors

• Jiang Lushan
• Chen Xiaojun
• Liu Xuanjie
• Guo Liangliang
• Ma Junde

Classifications

• B81B7/0058 Primary

  for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations · CPC title

• B81C2203/0109

  Bonding an individual cap on the substrate · CPC title

• B81C1/00825

  Protect against mechanical threats, e.g. against shocks, or residues (B81C1/00261 take precedence) · CPC title

• B81C1/00269 Primary

  Bonding of solid lids or wafers to the substrate · CPC title