Bond pad structure and fabricating method thereof

• US 8,525,354 B2
• Filed: 10/13/2011
• Issued: 09/03/2013
• Est. Priority Date: 10/13/2011
• Status: Active Grant

• Current Assignee: Marlin Semiconductor Limited (f/k/a Sandyford Semiconductor Limited) (Vector Capital Corporation)
• Original Assignee: United Microelectronics Corporation
• Inventors: Wu, Hui-Min, Wang, Ming-I, Huang, Chien-Hsin, Wang, Kuan-Yu, Hsieh, Kun-Che
• Primary Examiner(s): Lebentritt, Michael
• Assistant Examiner(s): QUINTO, KEVIN V
• Application Number:
  US13/272,289
• Publication Number:
  US 20130093104A1
• Time in Patent Office: 691 Days
• Field of Search: None
• US Class Current: 257/786
• CPC Class Codes: B81B 2207/015 the micromechanical device and the control or processing electronics being integrated on the same substrate
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/04073 Bonding areas specifically adapted for connectors of different types
• CPC Class Codes: H01L 2224/05567 the external layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 23/291 Oxides or nitrides or carbides, e.g. ceramics, glass
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 23/3192 Multilayer coating
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A bond pad structure comprises an interconnection structure and an isolation layer. The dielectric layer has an opening and a metal pad. The isolation layer is disposed on the interconnection structure and extends into the opening until it is in contact with the metal pad, whereby the sidewalls of the opening is blanketed by the isolation layer, and a portion of the metal pad is exposed from the opening.

Claims

1. A bond pad structure, comprising:

an interconnection structure, having an opening and a metal pad;

a metal oxide layer formed on a surface of the metal pad and disposed at the same side of the opening but not being exposed from the opening; and

an isolation layer, disposed on the interconnection structure and extending into the opening until in contact with the metal pad, whereby sidewalls of the opening are blanketed by the isolation layer, and a portion of the metal pad is exposed from the opening.

2. The bond pad structure of claim 1, wherein the isolation layer is made of a material selected from a group consisting of aluminum oxide (Al₂O₃), silicon nitride (SiN), silicon carbonitride (SiCN), amorphous silicon, organic polymer and the arbitrary combinations thereof.

3. The bond pad structure of claim 1, wherein the interconnection structure comprises:

an inter-layer dielectric (ILD), used to carry the metal pad; and

a passivation layer, disposed on the ILD, wherein the opening penetrates through the passivation layer to expose a portion of the metal pad.

4. The bond pad structure of claim 1, further comprising a silicon oxide layer embedded between the hard mask layer and the isolation layer.

5. The bond pad structure of claim 1, wherein the isolation layer has a bending angle formed on the corner where the sidewalls of the opening adjoins to the metal pad.

6. The bond pad structure of claim 1, further comprising a hard mask layer disposed on the isolation layer without in contact with the metal pad.

7. The bond pad structure of claim 6, wherein the hard mask layer is an aluminum layer.

8. A micro-electro-mechanical systems (MEMS) device, comprising:

a substrate;

a transistor, formed on the substrate;

a micro-electromechanical element, formed on the substrate; and

a bond pad structure, comprising;

an interconnection structure, formed on the substrate and having an opening and a metal pad electrically connected to the transistor and the micro-electromechanical element;

a metal oxide layer formed on the surface of the metal pad and disposed at the same side of the opening but not being exposed from the opening; and

an isolation layer disposed on the interconnection structure and extending into the opening until in contact with the metal pad, whereby the sidewalls of the opening are blanketed by the isolation layer, and a portion of the metal pad is exposed from the opening.

9. The MEMS device of claim 8, further comprising a hard mask layer formed on the isolation layer without in contact with the metal pad.

10. The MEMS device of claim 8, wherein the isolation layer has a bending angle formed on a corner where the sidewalls of the opening adjoin the metal pad.

11. The MEMS device of claim 8, further comprising a silicon oxide layer embedded between the hard mask layer and the isolation layer.

12. A method for fabricating a bond pad structure, comprising:

providing a substrate;

forming pluralities of patterned metal layers;

forming an inter-layer dielectric (ILD) to isolate the patterned metal layers on the substrate, so as to form at least one metal pad;

forming a metal oxide layer on the metal pad;

forming a passivation layer over the patterned metal layers and the ILD;

forming an opening in the passivation layer so as to expose a portion of the metal pad;

forming an isolation layer on the passivation layer to cover the sidewalls of the opening and the exposed metal pad; and

patterning the isolation layer to expose a portion of the metal pad from the opening.

13. The method of claim 12, further comprising steps of forming at least one transistor and a micro-electromechanical element prior to the formation of the interconnection structure.

14. The method of claim 12, wherein the isolation layer is made of a material selected from a group consisting of Al₂O₃, SiN, SiCN, amorphous silicon, organic polymer and the arbitrary combinations thereof.

15. The method of claim 12, further comprising steps of forming a hard mask layer on the isolation layer without in contact with the metal pad.

16. The method of claim 15, further comprising steps of:

forming a silicon oxide layer on the isolation layer prior to the formation of the hard mask; and

patterning the silicon oxide layer to make the patterned silicon oxide layer without beyond the opening.