Methods of forming packaged micro-electromechanical devices

• US 7,955,885 B1
• Filed: 01/09/2009
• Issued: 06/07/2011
• Est. Priority Date: 01/09/2009
• Status: Expired due to Fees

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Lei, Kuolung, Wang, Ye, Bhugra, Harmeet
• Primary Examiner(s): Mulpuri; Savitri
• Assistant Examiner(s): Ahmadi; Mohsen
• Application Number:
  US12/351,020
• Time in Patent Office: 879 Days
• Field of Search: 257/E21.499, 257/E21.532, 257/E21.705
• US Class Current: 438/51
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer

Abstract

Methods of forming packaged micro-electromechanical devices include forming a first substrate having a micro-electromechanical device therein, which extends adjacent a first surface of the first substrate. A first surface of a second substrate is then bonded to the first surface of the first substrate, to thereby encapsulate the micro-electromechanical device within a space provided between the first and second substrates. Subsequent to bonding, a second surface of the second substrate is selectively etched to define at least one through-substrate opening therein, which exposes an electrode of the micro-electromechanical device. Thereafter, the through-substrate opening is filled with an electrically conductive through-substrate via.

Claims

1. A method of forming a packaged micro-electromechanical device, comprising:

forming a first substrate having a micro-electromechanical device therein adjacent a first surface thereof;

bonding a first surface of a second substrate to the first surface of the first substrate;

then

selectively etching a second surface of the second substrate for a sufficient duration to define a through-substrate opening therein that exposes an electrode of the micro-electromechanical device; and

filling the through-substrate opening with an electrically conductive through-substrate via that contacts the exposed electrode concurrently with forming a seal ring that extends on the first and second surfaces of the first and second substrates, respectively, and hermetically seals the first and second substrates together, by conformally depositing a metal layer onto the first and second substrates and then patterning the deposited metal layer into the through-substrate via and the seal ring.

2. The method of claim 1, wherein the metal layer comprises AlCu.

3. The method of claim 1, wherein the seal ring defines a ring-shaped flange that surrounds the second substrate.

4. The method of claim 1, wherein said bonding is preceded by a step of forming a polymer layer on the first surface of the second substrate;

and wherein said bonding comprises bonding at least a portion of the polymer layer to at least a portion of the micro-electromechanical device.

5. The method of claim 4, wherein said bonding comprises bonding at least a portion of the polymer layer to the electrode of the micro-electromechanical device.

6. A method of forming a packaged micro-electromechanical device, comprising:

forming a first substrate having a micro-electromechanical device therein adjacent a first surface thereof;

bonding a first surface of a second substrate to the first surface of the first substrate;

then

selectively etching the second surface of the second substrate for a sufficient duration to define a through-substrate opening therein that exposes a portion of the micro-electromechanical device;

depositing an electrically conductive metal layer on the second surface of the second substrate and on the first surface of the first substrate and into the through-substrate opening; and

patterning the electrically conductive metal layer to define a seal ring that hermetically seals the first and second substrates together and concurrently define a through-substrate via that contacts the exposed portion of the micro-electromechanical device.

7. The method of claim 6, wherein said depositing is preceded by a step of thinning the second substrate.