Micro-electro mechanical systems switch and method of fabricating the same

• US 7,585,113 B2
• Filed: 05/24/2006
• Issued: 09/08/2009
• Est. Priority Date: 12/08/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Je, Chang Han, Lee, Jae Woo, Kang, Sung Weon
• Primary Examiner(s): Font; Frank G
• Assistant Examiner(s): Radkowski; Peter
• Application Number:
  US11/440,863
• Publication Number:
  US 20070170460A1
• Time in Patent Office: 1,203 Days
• Field of Search: 359/196, 359/227, 359/362, 359/838, 385 15- 17, 333/105, 333/262, 335/78
• US Class Current: 384/147
• CPC Class Codes: B81B 2201/016 having a bridge fixed on two ends and connected to one or more dimples
• CPC Class Codes: B81B 3/0013 Structures dimensioned for mechanical prevention of stiction, e.g. spring with increased stiffness
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• CPC Class Codes: H01H 59/0009 making use of micromechanics

Abstract

A MEMS switch and a method of manufacturing the same are disclosed. The MEMS switch includes: a substrate including a trench, a ground line and a signal line having an opened portion; a moving plate separated from the substrate at a predetermined space and including a contact member for connecting an electrode plate and the opened portion and having a deep corrugate to insert the trench; and a supporting member for supporting the moving plate. Such a MEMS switch prevents the thermal expansion and the stiction problem.

Claims

1. A MEMS (micro-electro mechanical systems) switch comprising;

a substrate including a plurality of trenches, a ground line and a signal line having an opened portion;

a moving plate separated from the substrate at a predetermined space and including an electrode plate, a contact member for connecting the opened portion and a plurality of deep corrugates, wherein each deep corrugate is to be inserted into a respective trench of the plurality of trenches, each deep corrugate comprising a respective insulating layer and a respective electrode plate, and a groove is formed at each deep corrugate; and

a supporting member for supporting the moving plate.

2. The MEMS switch of claim 1, wherein each trench of the plurality of trenches, the ground line and the signal line are formed to be separated one another at a predetermined distance in a first direction of the substrate, and

the supporting member is formed in at least one of portions at both ends of the substrate in a vertical direction from the first direction.

3. The MEMS switch of claim 2, wherein the signal line is formed on the center of the substrate,

the supporting member is formed at both ends of the substrate,

the ground line is formed between the signal line and the supporting member, and

each trench of the plurality of trenches is formed between the supporting member and the ground line and between the signal line and the ground line.

4. The MEMS switch of claim 1, wherein the supporting member is a supporting metal formed on the substrate and electrically connected to the electrode plate.

5. The MEMS switch of claim 1, wherein the moving plate further includes a supporting protrusion formed on the ground line and supporting the moving plate to be separated from the substrate at a predetermined space.

6. The MEMS switch of claim 5, wherein the supporting protrusion includes a wedge shape groove inside thereof.

7. The MEMS switch of claim 1, wherein the moving plate includes an insulating layer on the bottom of the electrode plate to prevent the ground line from being shorted.

8. The MEMS switch of claim 7, wherein a conductive switching line electrically isolated from the electrode plate is formed on the insulating layer above the opened portion, and

the contact member is connected to the conductive switching line and is projected by passing through a predetermined position of the insulating layer where the contact member contacts the both ends of the opened portion of the signal line.

9. The MEMS switch of claim 1, wherein an insulating layer is formed on the ground line.

10. The MEMS switch of claim 1, wherein the moving plate is made of material having elastic restoring force to move in the upward direction and the downward direction.

11. The MEMS switch of claim 10, wherein the ground line is a first electrode, the electrode plate is a second electrode, and the signal line of the opened portion contacts to the contact member by electrostatic attractive force generated from the ground line and the electrode plate when the voltage is supplied to the first and the second electrodes.

12. A method of manufacturing a MEMS (micro-electro mechanical systems) switch comprising:

forming a plurality of trenches, a ground line and a signal line having an opened portion on a substrate in a first direction;

forming a supporting member in at least one of both ends of the substrate in a vertical direction from the first direction;

forming a sacrificial layer having a predetermined thickness on the entire surface of the substrate after forming the supporting member;

forming a moving plate having an electrode layer connected to the supporting member on the sacrificial layer and a contact member for connecting the opened portion, wherein forming the moving plate includes forming an insulating layer on the entire surface of the substrate;

removing the sacrificial layer; and

wherein after removing the sacrificial layer, the moving plate forms a respective deep corrugate above each of the plurality of trenches, each respective deep corrugate including the insulating layer and the electrode layer, and a groove is formed at each deep corrugate.

13. The method of claim 12, wherein the signal line is formed on the center of the substrate,

the supporting member is formed at both ends of the substrate,

the ground line is formed between the signal line and the supporting member, and

each trench of the plurality of trenches is formed between the supporting member and the ground line and between the signal line and the ground line.

14. The method of claim 12, wherein the forming of the sacrificial layer includes exposing a predetermined portion of the ground line and the supporting member by etching the sacrificial layer.

15. The method of claim 14, wherein the forming of the moving plate further includes:

forming the insulating layer on the entire surface of the substrate after exposing;

forming an contact member by etching the insulating layer and the sacrificial layer at both ends of the signal line of the opened portion and burying a conductive material; and

forming a switching electrode line by forming an electrode layer on the insulating layer and the contact member and etching a predetermined portion around the electrode layer on the contact member.

16. The method of claim 15, wherein in the etching of the insulating layer and the sacrificial layer, the insulating layer is exposed through etching the insulating layer on the supporting member.

17. The method of claim 15, wherein the forming of the switching electrode line, a supporting protrusion is formed through etching the electrode layer formed on the insulating layer of the predetermined portion of the ground line.

18. The method of claim 12, wherein the moving plate is formed of materials having elastic restoring force.