ROTATIONAL MEMS DEVICE HAVING PIEZO-RESISTOR SENSOR

• US 20080168670A1
• Filed: 09/20/2007
• Published: 07/17/2008
• Est. Priority Date: 01/15/2007
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Shin, Seong-ho, Cho, Jin-woo, Ko, Young-chul, Choi, U-hyuk
• Granted Patent: US 7,642,576 B2
• Time in Patent Office: Days
• US Class Current: 33/1PT
• CPC Class Codes: G01D 5/185 using piezoelectric sensors
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams

Abstract

A rotational micro-electromechanical system (MEMS) having a piezo-resistor sensor is provided. The rotational MEMS device includes a pair of torsion springs that support a stage, four resistors, at least one of the resistors being formed along a center axis of the torsion springs, and electrical signal cables connected to the four resistors, wherein at least one of the torsion springs is formed in a <100> direction on an n-type silicon substrate having a (100) plane, and the resistors formed on the at least one of the torsion springs are formed in a <110> group direction.

Claims

1. A rotational micro-electromechanical system (MEMS) device comprising:

a pair of torsion springs which support a stage;

four resistors, at least one of the resistors being formed along a center axis of at least one of the torsion springs; and

electrical signal cables connected to the four resistors,

wherein the at least one of the torsion springs is formed in a <

100>

direction on an n-type silicon substrate having a (100) plane, and the resistors formed on the at least one of the torsion springs are formed in a <

110>

group direction.

2. The rotational MEMS device of claim 1, wherein the resistors are doped with a p-type impurity.

3. The rotational MEMS device of claim 2, wherein the p-type impurity is boron.

4. The rotational MEMS device of claim 3, wherein the resistors on the at least one of the torsion springs are formed in a direction perpendicular to each other.

5. The rotational MEMS device of claim 4, wherein the four resistors are disposed on the at least one of the torsion springs in a W shape.

6. A rotational micro-electromechanical system (MEMS) device comprising:

a pair of torsion springs which support a stage;

a cross shaped resistor defining four ends and being formed along a center axis of at least one of the torsion springs; and

electrical signal cables respectively connected to the four ends of the resistor,

wherein the at least one of the torsion springs is formed on an n-type silicon substrate having a (100) plane and is formed in a <

100>

direction, and at least two ends of the resistor which are opposite to each other are formed in a <

100>

direction.

7. The rotational MEMS device of claim 6, wherein the resistor is doped with a p-type impurity.

8. The rotational MEMS device of claim 7, wherein the p-type impurity is boron.

9. The rotational MEMS device of claim 6, wherein a reference voltage is applied to two other ends of the resistor formed in a perpendicular direction to the two ends of the resistor formed in the <

100>

direction.