MEMS capping method

• US 9,731,960 B2
• Filed: 02/08/2016
• Issued: 08/15/2017
• Est. Priority Date: 04/21/2014
• Status: Active Grant

• Current Assignee: Semiconductor Manufacturing International Corporation
• Original Assignee: Semiconductor Manufacturing International Corporation
• Inventors: Guo, Liangliang, Ma, Junde, Jiang, Lushan, Chen, Xiaojun, Liu, Xuanjie
• Primary Examiner(s): Everhart, Caridad
• Assistant Examiner(s): SINGAL, ANKUSH K
• Application Number:
  US15/018,740
• Publication Number:
  US 20160152467A1
• Time in Patent Office: 554 Days
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 1/00825 Protect against mechanical threats, e.g. against shocks, or residues B81C1/00261 take precedence
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate

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.

Claims

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, H₂O₂ and H₂O having a concentration ratio of HF;

H₂O₂;

H₂O=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.