Microelectronic device and electronic apparatus

• US 9,083,309 B2
• Filed: 11/16/2011
• Issued: 07/14/2015
• Est. Priority Date: 11/30/2010
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kanemoto, Yoko
• Primary Examiner(s): Le, Thao X
• Assistant Examiner(s): SWAN, GARDNER W.S
• Application Number:
  US13/297,692
• Publication Number:
  US 20120133449A1
• Time in Patent Office: 1,336 Days
• Field of Search: 438/52, 331/154, 216/13, 361/748, 174/260, 298/52, 257/E21.158
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 3/0013 Structures dimensioned for mechanical prevention of stiction, e.g. spring with increased stiffness
• CPC Class Codes: B81C 1/00968 Methods for breaking the stiction bond
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 9/2457 Clamped-free beam resonators

Abstract

A movable section located in a hollow portion covered with a wall and a first sealing layer which are on a substrate and the first sealing layer located in an area facing the movable section are provided, the movable section is located between the substrate and the first sealing layer, and at least part of the movable section and the first sealing layer is an electric conductor.

Claims

1. A microelectronic device comprising:

a movable section located in a hollow portion covered with a covering section comprising a lid section and a sidewall section on a substrate;

a fixing section that is provided on the substrate, the fixing section facing the movable section;

the lid section located in the covering section in an area facing the movable section;

a side wall insulating film that is located in the covering section between the substrate and the lid section and provides isolation between the substrate and the lid section;

a switch circuit that is configured by a three-terminal switch selectively connecting among the movable section, the lid section and the sidewall section so as to switch between a first state and a second state; and

a voltage circuit that supplies a voltage,

wherein

the side wall insulating film is located between the lid section and the sidewall section so as to electrically separate the lid section from the sidewall section,

the movable section is located between the substrate and the lid section,

the movable section, the sidewall section and the lid section are electric conductors,

when the first state is selected by the switch circuit, the sidewall section and the lid section are connected to a ground potential at the same time, and

when the second state is selected by the switch circuit, the voltage circuit supplies the voltage between the lid section and the movable section at the same time and the sidewall section is connected to the ground potential.

2. The microelectronic device according to claim 1, wherein at least part of the fixing section is an electric conductor.

3. The microelectronic device according to claim 2, wherein the side wall insulating film is located in a position closer to the lid section than the movable section.

4. The microelectronic device according to claim 1, wherein the fixing section is a fixed electrode, and

a first distance between the lid section and the movable section is greater than a second distance between the movable section and the fixed electrode.

5. The microelectronic device according to claim 1, further comprising:

an oscillating circuit generating a waveform by using the movable section.

6. An electronic apparatus comprising:

the microelectronic device according to claim 1; and

an oscillation circuit that generates a waveform in accordance with movement of the moveable section.

7. An electronic apparatus comprising:

the microelectronic device according to claim 2; and

an oscillation circuit that generates a waveform in accordance with movement of the moveable section.

8. An electronic apparatus comprising:

the microelectronic device according to claim 3; and

an oscillation circuit that generates a waveform in accordance with movement of the moveable section.

9. An electronic apparatus comprising:

the microelectronic device according to claim 4; and

an oscillation circuit that generates a waveform in accordance with movement of the moveable section.

10. An electronic apparatus comprising:

the microelectronic device according to claim 5; and

an oscillation circuit that generates a waveform in accordance with movement of the moveable section.

11. The microelectronic device according to claim 1, wherein when the movable section is separated from the fixing section, the voltage is not applied between the lid section and the movable section, and the lid section is connected to the ground potential.

12. An microelectronic device comprising:

a substrate;

a covering section that is located on the substrate and covers a hollow portion;

a movable section located in the hollow portion, the movable section in which at least part thereof is an electric conductor;

a fixing section that is provided on the substrate, the fixing section facing the movable section; and

a switch circuit that switches between a first state and a second state,

wherein

the covering section has a side wall surrounding the movable section in a plan view and a lid section that overlaps the side wall in the plan view,

the side wall includes a side wall insulating film and a surrounding wall,

the lid section and the surrounding wall are electric conductors,

the side wall insulating film is located between the lid section and the surrounding wall so as to electrically separate the lid section from the surrounding wall,

the switch circuit is configured by a three-terminal switch selectively connecting among the movable section, the lid section and the surrounding wall so as to switch between the first state and the second state,

when the first state is selected by the switch circuit, the surrounding wall and the lid section are connected to a ground potential at the same time, and

when the second state is selected by the switch circuit, a voltage is applied between the lid section and the movable section at the same time and the surrounding wall is connected to the ground potential.

13. The microelectronic device according to claim 12, wherein when the movable section is separated from the fixing section, the voltage is not applied between the lid section and the movable section, and the lid section is connected to the ground potential.