Micromirror manufacturing method

• US 20090149004A1
• Filed: 12/24/2007
• Published: 06/11/2009
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Ichikawa, Hirotoshi, Ishii, Fusao
• Granted Patent: US 7,901,969 B2
• Time in Patent Office: Days
• US Class Current: 438/465
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81C 3/002 Aligning microparts
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A micro-mirror manufacturing method for dividing a plurality of micro-mirror devices each having at least one mirror, formed on a semiconductor wafer into individual micro-mirror devices can be provided. The manufacturing method comprises a step of depositing an inorganic protection layer on the mirror before separating the micro-mirror devices from the wafer and a step of removing the inorganic protection layer after separating the micro-mirror devices from the wafer.

Claims

1. A micro-electrical-mechanical-systems(MEMS) manufacturing method for dividing a plurality of MEMS devices each having at least one movable element, formed on a semiconductor wafer into individual MEMS devices, comprising:

Depositing an inorganic protection layer on the movable element before separating the MEMS devices from the wafer; and

removing the inorganic protection layer after separating the MEMS devices from the wafer.

2. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

a silicon compound is deposited as the inorganic protection layer.

3. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

a silicon dioxide (SiO₂) is deposited as the inorganic protection layer.

4. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

a silicon carbide (SiC) is deposited as the inorganic protection layer.

5. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

the inorganic protection layer is removed by dry etching.

6. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

an inorganic layer is used for a sacrificial layer for providing a space above the wafer and forming the movable elements.

7. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

the same material as the inorganic protection layer is used for a sacrificial layer for providing a space above the wafer and forming the movable elements.

8. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, wherein

the MEMS devices are separate from the wafer in an environment of being lower than a melting point of the inorganic protection layer and

the inorganic protection layer is removed by exposing the MEMS devices to an environment of being higher than a melting point of the inorganic protection layer after separating the MEMS devices from the wafer.

9. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, further comprising

providing at least one auxiliary member for maintaining arrangement before separating the MEMS devices from the wafer on the back of the wafer.

10. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, further comprising

providing an opening in a finely determined relative position between the package and the MEMS device of a base of the wafer before separating the MEMS devices from the wafer on the back of the wafer.

11. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 1, said MEMS is micro-mirror device.

12. A micro-electrical-mechanical-systems(MEMS) manufacturing method for making a plurality of movable elements formed on a semiconductor wafer, comprising:

Depositing a first inorganic sacrificial layer on the substrate; and

depositing a second inorganic sacrificial layer on the said first inorganic sacrificial layer or the structural layer.

13. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 12, wherein

the same material is used for a said first and second sacrificial layer.

14. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 12, wherein

a silicon dioxide (SiO₂) is deposited as the inorganic sacrificial layer.

15. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 12, wherein

said sacrificial layers are removed by the same etchant.

16. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 12, said MEMS is micro-mirror device.

17. The micro-electrical-mechanical-systems(MEMS) manufacturing method according to claim 12, wherein

said sacrificial layers are removed in same step.