Method of fabrication of Al/Ge bonding in a wafer packaging environment and a product produced therefrom

Patent metadata

Field	Value
Publication number	US-9139428-B2
Application number	US-201414157456-A
Country	US
Kind code	B2
Filing date	Jan 16, 2014
Priority date	Mar 18, 2005
Publication date	Sep 22, 2015
Grant date	Sep 22, 2015

Abstract

A method of bonding of germanium to aluminum between two substrates to create a robust electrical and mechanical contact is disclosed. An aluminum-germanium bond has the following unique combination of attributes: (1) it can form a hermetic seal; (2) it can be used to create an electrically conductive path between two substrates; (3) it can be patterned so that this conduction path is localized; (4) the bond can be made with the aluminum that is available as standard foundry CMOS process. This has the significant advantage of allowing for wafer-level bonding or packaging without the addition of any additional process layers to the CMOS wafer.

First claim

What is claimed is:

1. A MEMS device comprising:
a first substrate including a microelectromechanical systems (MEMS) feature and a patterned germanium layer; and
a second substrate, including a patterned aluminum layer, wherein the germanium of the patterned germanium layer of the first substrate is in direct contact with and matched to the aluminum of the patterned aluminum layer of the second substrate to form a contact area, wherein in the contact area the patterned aluminum layer is properly patterned to match patterned germanium layer.

2. The MEMS device of claim 1 , wherein the second substrate includes electrical circuits.

3. The MEMS device of claim 1 , wherein the first and second substrates are electrically connected.

4. The MEMS device of claim 1 , wherein the patterned aluminum layer and the patterned germanium layer form a seal ring.

5. The MEMS device of claim 1 , wherein the direct contact between germanium and the aluminum comprises a eutectic bond.

Assignees

• Invensense Inc

Inventors

• Nasiri Steven S
• Flannery Jr Anthony F

Classifications

• B81C1/00238 Primary

  Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure · CPC title

• B23K20/023

  Thermo-compression bonding · CPC title

• B81B2203/0315

  Cavities · CPC title

• B81B2207/012

  the micromechanical device and the control or processing electronics being separate parts in the same package · CPC title

• B81C1/00269

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