Mems capping method

Patent metadata

Field	Value
Publication number	US-2016152467-A1
Application number	US-201615018740-A
Country	US
Kind code	A1
Filing date	Feb 8, 2016
Priority date	Apr 21, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

A method for fabricating a MEMS device includes providing a substrate having a front surface and a back surface, and forming a protruding engagement member on the front surface of the substrate. The protruding engagement member has an inner periphery defining a groove and an outer periphery. The method also includes forming a first trench having a first depth along the outer periphery, forming a patterned mask layer on the protruding engagement member covering the groove and exposing a portion of the first trench. The method further includes etching the exposed portion of the first trench to form a second trench having a second depth, removing the patterned mask layer, bonding the substrate with a MEMS substrate to form the MEMS device, and thinning the back surface to within the second depth. The method prevents dust from being deposited on the MEMS substrate as in the case of cutting.

First claim

1 - 16 . (canceled)

17 . 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.

18 . The MEMS device of claim 17 , further comprising, prior to bonding:
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.

19 . The MEMS device of claim 17 , 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.

20 . The MEMS device of claim 17 , 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

Inventors

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

Classifications

• B81C2203/0109

  Bonding an individual cap on the substrate · CPC title

• B81B7/0058 Primary

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