Self-shadowing MEM structures

• US 6,824,278 B2
• Filed: 03/15/2002
• Issued: 11/30/2004
• Est. Priority Date: 03/15/2002
• Status: Expired due to Fees

• Current Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Original Assignee: MEMX, Inc. (Lumentum Holdings Inc.)
• Inventors: Rodgers, Murray Steven, Miller, Samuel Lee
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US10/098,266
• Publication Number:
  US 20030174929A1
• Time in Patent Office: 991 Days
• Field of Search: 359/838, 359/883-884, 385/16-18, 385/40, 430/22-24, 430/311-314, 430/321, 438/24, 438/31, 438/48-53, 438/72, 438/199-200
• US Class Current: 359/838
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: B81C 1/00833 Methods for preserving structures not provided for in groups B81C1/00785 - B81C1/00825
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841

Abstract

Self-shadowed microelectromechanical structures such as self-shadowed bond pads, fuses and compliant members and a method of fabricating self-shadowing microelectromechanical structures that anticipate and accommodate blanket metalization process steps are disclosed. In one embodiment, a self-shadowed bond pad (10) configured for shadowing an exposed end (44A) of a shielded interconnect line (44) connected to the bond pad (10) from undesired metalization during a metalization fabrication process step includes electrically connected overlaying first, second and third bond pad areas (42, 72, 92) patterned from respective first, second and third layers (40, 70, 90) of material deposited on a substrate (20). The exposed end (44A) of the interconnect line (44) abuts an edge of the first bond pad area (42). The third bond pad area (92) includes at least one tab portion (94) extending laterally from an edge of the third bond pad area (92) to shadow an area on the substrate (20) including the exposed end (44A) of the interconnect line (44) abutting the edge of the first bond pad area (42).

Claims

1. A self-shadowed microelectromechanical structure configured for shadowing a portion thereof from undesired metalization during a metalization fabrication process step, said self-shadowed microelectromechanical structure comprising:

a substrate;

a lower layer of material deposited on said substrate;

a lower structure patterned from said lower layer of material having at least a portion thereof that is to remain non-metalized;

an upper layer of material deposited on said substrate; and

an upper structure patterned from said upper layer of material, wherein said upper structure includes a laterally extending portion thereof that extends laterally from said upper structure to shadow an area on said substrate including the portion of said lower structure that is to remain non-metalized.

2. The self-shadowed microelectromechanical structure of claim 1 wherein said lower structure comprises an interconnect line and said upper structure comprises a bond pad area.

3. The self-shadowed microelectromechanical structure of claim 2 wherein said laterally extending portion of said bond pad area comprises a tab extending laterally from an edge of said bond pad area.

4. The self-shadowed microelectromechanical structure of claim 2 wherein said laterally extending portion of said bond pad area comprises a cantilevered edge of said bond pad area.

5. The self-shadowed microelectromechanical structure of claim 1 wherein said lower structure comprises an interconnect line and said upper structure comprises a tab extending laterally from a post extending upward from a shield structure overlying said interconnect line.

6. The self-shadowed microelectromechanical structure of claim 1 wherein said upper structure comprises a positionable mirror and said lower structure comprises at least one filament holding said mirror in place until said filament is severed.

7. The self-shadowed microelectromechanical structure of claim 1 wherein said upper structure comprises a positionable mirror and said lower structure comprises at least one compliant member extending outward from an edge of said mirror.

8. The self-shadowed microelectromechanical structure of claim 6 or 7 wherein said laterally extending portion of said mirror comprises a tab extending laterally from an edge of said mirror.

9. The self-shadowed microelectromechanical structure of claim 6 or 7 wherein said laterally extending portion of said mirror comprises a cantilevered edge of said mirror.

10. The self-shadowed microelectromechanical structure of claim 1 wherein at least one of said lower layer of material and said upper layer of material comprises an electrically conductive material.

11. The self-shadowed microelectromechanical structure of claim 10 wherein said substrate comprises silicon and said electrically conductive material comprises doped polysilicon.