Ultrathin form factor MEMS microphones and microspeakers

• US 20050095814A1
• Filed: 03/15/2004
• Published: 05/05/2005
• Est. Priority Date: 11/05/2003
• Status: Abandoned Application

• Current Assignee: Akustica Incorporated
• Original Assignee: Akustica Incorporated
• Inventors: Ciferno, Raymond A., Zhu, Xu
• Application Number:
  US10/800,470
• Publication Number:
  US 20050095814A1
• Time in Patent Office: Days
• US Class Current: 438/459
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81C 1/00182 Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer
• CPC Class Codes: H04R 19/005 using semiconductor materials

Abstract

A process of fabricating a plurality of devices containing MEMS membranes (sealed micro-machined meshes) may begin with certain process steps being performed from the top side of a substrate carrying the plurality of devices. A carrier wafer is attached to the top side of the substrate. The thickness of the substrate is reduced using any known technique. The fabrication process is continued by performing various process steps from the back side of the substrate. Alternatively, a process of fabricating a plurality of devices containing MEMS membranes may begin with attaching a carrier wafer to a top side of a substrate carrying the plurality of devices. The thickness of the substrate is reduced. Process steps are then performed from the back side of the substrate. A carrier wafer is attached to the back side of the substrate and the carrier wafer on the top side of the substrate is removed. Thereafter, process steps are performed from the top side of the substrate. This disclosure encompasses a process for fabricating a MEMS device in which the thickness of a substrate is reduced; a carrier wafer is attached to one of the top side and back side of the substrate for at least a part of the process of fabricating the MEMS device. Because of the rules governing abstracts, this abstract should not be relied upon in construing the claims.

Claims

1. A process, comprising:

performing certain process steps from the top side of a substrate carrying a plurality of devices, at least certain of the devices having a micro-machined mesh;

attaching a carrier wafer to the top of the substrate;

reducing the thickness of the substrate; and

continuing the process of fabricating the plurality of devices from the back side of the substrate.

2. The process of claim 1 wherein said performing includes forming and patterning a layer of resist.

3. The process of claim 1 wherein said performing includes forming a plurality of meshes.

4. The process of claim 1 wherein said continuing includes forming vent holes.

5. The process of claim 4 additionally comprising attaching a carrier wafer to the back side of the substrate and removing the carrier wafer from the top side of the substrate, said process additionally comprising forming and releasing a plurality of meshes from the top side of the substrate.

6. The process of claim 5 additionally comprising singulating the plurality of devices.

7. A process, comprising:

attaching a carrier wafer to a top side of a substrate carrying a plurality of devices, at least certain of said devices including a mesh;

reducing the thickness of said substrate;

performing process steps from the back side of said substrate;

attaching a carrier wafer to the back side of said substrate and removing said carrier wafer from the top side of said substrate; and

performing process steps from the top side of said substrate.

8. The process of claim 7 wherein said performing process steps from the back side of the substrate includes forming vent holes.

9. The process of claim 7 wherein said performing process steps from the top side of said substrate includes forming and releasing a plurality of meshes.

10. The process of claim 9 additionally comprising singulating the plurality of devices.

11. In a process for fabricating a MEMS device, the improvement comprising:

reducing the thickness of a substrate; and

attaching a carrier wafer to one of the top side and back side of the substrate for use during at least a part of the process of fabricating the MEMS device.

12. In a process for fabricating a MEMS device, the improvement comprising:

reducing the thickness of a substrate carrying a plurality of devices;

using a carrier wafer attached to the top side of said substrate while at least certain process steps are performed from the back side; and

using a carrier wafer attached to the back side of said substrate while at least certain process steps are performed from the top side.