Process for manufacturing mirror devices using semiconductor technology

• US 6,577,427 B1
• Filed: 05/25/2001
• Issued: 06/10/2003
• Est. Priority Date: 02/20/2001
• Status: Expired due to Fees

• Current Assignee: Nayna Networks, Inc.
• Original Assignee: Nayna Networks, Inc.
• Inventors: Gee, Dale A., Sathe, Abhijeet D.
• Primary Examiner(s): Phan, James
• Application Number:
  US09/866,312
• Time in Patent Office: 746 Days
• Field of Search: 359/198, 359/199, 359/223, 359/224, 359/838, 359/848, 359/850, 359/871, 359/872, 359/900, 385/16, 385/18
• US Class Current: 359/224.1
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• 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 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: Y10S 359/90 Methods
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

A method for fabricating a mirror array from multilayered substrate structures. The method forms a release layer overlying a material layer, which is formed on an insulating layer of multilayered substrate. The insulating layer is sandwiched between the material layer and a handle layer. As merely an example, the material layer is a silicon layer defined over a silicon dioxide layer on a silicon on insulator structure, commonly known as SOI. The method forms an opening in the release layer to expose a portion of the material layer. The method forms a torsion bar layer overlying the release layer and in the opening to connect to the material layer; and removes the release layer to hang the material layer from the torsion bar layer.

Claims

1. A method for fabricating a mirror array from multilayered substrate structures, the method comprising:

forming a release layer overlying a material layer, the material layer being formed on an insulating layer of substrate, the insulating layer being sandwiched between the material layer and a handle layer;

forming an opening in the release layer to expose a portion of the material layer;

forming a torsion bar layer overlying the release layer and in the opening to connect to the material layer; and

removing the release layer to hang the material layer from the torsion bar layer.

2. The method of claim 1 wherein the material layer defines a mirror device.

3. The method of claim 1 wherein the material layer defines a mirror device that is supported by the torsion bar layer after removing the release layer.

4. The method of claim 1 further comprising removing material from the handle layer such that the insulating layer is exposed.

5. The method of claim 4 further comprising selectively removing the insulating layer to release the material layer from a backside of the material layer.

6. The method of claim 1 wherein the material layer comprises single crystal silicon.

7. The method of claim 1 wherein the insulating layer comprises silicon dioxide and the handle wafer comprises silicon.

8. The method of claim 1 wherein the release layer is an interlayer dielectric material.

9. The method of claim 8 wherein the interlayer dielectric material is selected from an oxide layer, and a doped oxide layer.

10. The method of claim 1 wherein the torsion bar layer is coupled to a support structure.

11. A method for fabricating optical switching devices from multilayered substrate structures, the method comprising:

forming a release layer overlying a mirror device defined in a material layer, the material layer being formed on an insulating layer of substrate, the insulating layer being sandwiched between the material layer and a handle layer, the release layer being of a selected thickness and having a substantially planarized surface;

forming an opening in the release layer to expose a portion of the material layer, the opening being positioned in a spatial manner about a center region of the mirror device;

forming a torsion bar layer overlying the release layer and in the opening to connect to the mirror device in the material layer; and

removing the insulating layer attached to the mirror device and the release layer attached to the mirror device to suspend the mirror device about the center region with the torsion bar layer.