Method and structure for forming a gyroscope and accelerometer

• US 8,207,004 B2
• Filed: 11/18/2009
• Issued: 06/26/2012
• Est. Priority Date: 01/03/2005
• Status: Active Grant

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Chen, Dongmin, Payne, Justin, Tseng, Li-Tien
• Primary Examiner(s): Cao, Phat X
• Assistant Examiner(s): Doan, Nga
• Application Number:
  US12/620,872
• Publication Number:
  US 20100109102A1
• Time in Patent Office: 951 Days
• Field of Search: 438/50, 438/51, 438/52, 438/53, 438/54, 257/E21.499, 257/E29.324
• US Class Current: 438/51
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type
• CPC Class Codes: G01P 2015/0831 the mass being of the paddle type having the pivot axis between the longitudinal ends of the mass, e.g. see-saw configuration

Abstract

A method for fabricating a micro electromechanical device includes providing a first substrate including control circuitry. The first substrate has a top surface and a bottom surface. The method also includes forming an insulating layer on the top surface of the first substrate, removing a first portion of the insulating layer so as to form a plurality of standoff structures, and bonding a second substrate to the first substrate. The method further includes thinning the second substrate to a predetermined thickness and forming a plurality of trenches in the second substrate. Each of the plurality of trenches extends to the top surface of the first substrate. Moreover, the method includes filling at least a portion of each of the plurality of trenches with a conductive material, forming the micro electromechanical device in the second substrate, and bonding a third substrate to the second substrate.

Claims

1. A method for fabricating a micro electromechanical device, the method comprising:

providing a first substrate including control circuitry, the first substrate having a top surface and a bottom surface;

forming an insulating layer on the top surface of the first substrate;

removing a first portion of the insulating layer so as to form a plurality of standoff structures;

bonding a second substrate to the first substrate, the second substrate having an upper surface and a lower surface;

thinning the second substrate to a predetermined thickness;

forming a plurality of trenches in the second substrate, each of the plurality of trenches extending to the top surface of the first substrate;

filling at least a portion of each of the plurality of trenches with a conductive material;

forming the micro electromechanical device in the second substrate; and

bonding a third substrate to the second substrate.

2. The method of claim 1 wherein the first substrate comprises a CMOS substrate.

3. The method of claim 1 wherein the plurality of trenches extend from the upper surface of the second substrate to the top surface of the first substrate.

4. The method of claim 1 wherein the second substrate comprises a silicon-on-insulator (SOI) substrate.

5. The method of claim 1 wherein the micro electromechanical device includes elements of a gyroscope or an accelerometer.

6. The method of claim 1 wherein bonding a second substrate to the first substrate includes using at least one of a covalent bonding, glass frit bonding, or eutectic bonding technique.