Method of anodically bonding a multilayer device with a free mass

• US 6,548,321 B1
• Filed: 10/23/2001
• Issued: 04/15/2003
• Est. Priority Date: 10/23/2001
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Sawyer, William David
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): PERT, EVAN T
• Application Number:
  US10/004,145
• Publication Number:
  US 20030077876A1
• Time in Patent Office: 539 Days
• Field of Search: 438/48, 438/50, 438/51, 438/52, 438/53, 438/455, 438/456, 438/458
• US Class Current: 438/50
• CPC Class Codes: B81C 1/0092 For avoiding stiction during the manufacturing process of the device, e.g. during wet etching
• CPC Class Codes: B81C 1/00976 Control methods for avoiding stiction, e.g. controlling the bias voltage
• CPC Class Codes: B81C 2203/031 Anodic bondings
• CPC Class Codes: B81C 3/001 Bonding of two components
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support

Abstract

A method of anodically bonding a multilayer device with a free mass includes positioning a support layer on either side of a free mass structure including a free mass with an electrode on each layer proximate the free mass; connecting both electrodes and the free mass to a node at a floating potential and applying a voltage across the layers and free mass structure to bond at least one of the layers to the free mass structure.

Claims

1. A method of anodically bonding a multilayer device with a free mass comprising:

positioning at least one support layer on either side of a free mass structure including a free mass with an electrode proximate to the free mass on said at least one support layer;

connecting said electrode and the free mass to a node at a floating potential; and

applying a voltage across the at least one layer and free mass structure to bond the at least one support layer to the free mass structure.

2. The method of anodically bonding a multilayer device with a free mass of claim 1 in which said free mass is a proof mass.

3. The method of anodically bonding a multilayer device with a free mass of claim 1 in which said at least one support layer and free mass include different materials.

4. The method of anodically bonding a multilayer device with a free mass of claim 3 in which said at least one support layer includes glass and said free mass includes silicon.

5. The method of anodically bonding a multilayer device with a free mass of claim 1 in which said node is contiguous with said multilayer device.

6. The method of anodically bonding a multilayer device with a free mass of claim 1 in which said multilayer device is one of a plurality formed in a wafer structure.

7. The method of anodically bonding a multilayer device with a free mass of claim 6 in which each said multilayer device has a node associated with it.

8. The method of anodically bonding a multilayer device with a free mass of claim 7 in which said wafer structure is diced into individual multilayer devices and the dicing disconnects the at least one support layer and free mass from said floating potential node.

9. The method of anodically bonding a multilayer device with a free mass of claim 6 in which said wafer structure includes two wafers which form support layers with a third wafer between them forming the free mass structure.