SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20170341929A1
• Filed: 02/24/2015
• Published: 11/30/2017
• Est. Priority Date: 02/24/2015
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: OKUMURA, Mika
• Granted Patent: US 10,252,905 B2
• Time in Patent Office: Days
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• CPC Class Codes: B81C 1/00825 Protect against mechanical threats, e.g. against shocks, or residues B81C1/00261 take precedence
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B81C 2201/013 Etching
• 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 2015/082 for two degrees of freedom of movement of a single mass
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: G01P 2015/0871 using stopper structures for limiting the travel of the seismic mass

Abstract

A semiconductor device includes a substrate, a beam, a movable structural body, a first stopper member, a second stopper member and a third stopper member. The first stopper member is arranged with a first gap from the movable structural body in an in-plane direction. The second stopper member is arranged with a second gap from the movable structural body in an out-of-plane direction. The third stopper member is arranged opposite to the second stopper member with the movable structural body interposed therebetween in the out-of-plane direction, and is arranged with a third gap from the movable structural body. Consequently, there can be provided a semiconductor device in which excessive displacement of the movable structural body can be suppressed to thereby suppress damage to and breakage of the beam supporting the movable structural body, and a method of manufacturing the same.

Claims

1. A semiconductor device comprising:

a substrate having a surface;

a beam supported by the substrate;

a movable structural body supported by the beam so as to be displaceable in an in-plane direction and an out-of-plane direction with respect to the surface of the substrate;

a first stopper member supported by the substrate and arranged, with the movable structural body being in a stationary state, with a first gap from the movable structural body in the in-plane direction;

a second stopper member supported by the first stopper member and arranged, with the movable structural body being in a stationary state, with a second gap from the movable structural body in the out-of-plane direction; and

a third stopper member supported by the first stopper member, arranged opposite to the second stopper member with the movable structural body interposed therebetween in the out-of-plane direction, and arranged, with the movable structural body being in a stationary state, with a third gap from the movable structural body.

2. The semiconductor device according to claim 1, wherein

each of the first gap, the second gap and the third gap has a dimension smaller than an amount of displacement that causes stress that causes a fracture of the beam due to displacement of the movable structural body in the in-plane direction and out-of-plane direction.

3. The semiconductor device according to claim 1, wherein

the first stopper member and the third stopper member are formed of an identical film.

4. A method of manufacturing a semiconductor device, comprising:

forming

a beam supported by a substrate having a surface,

a movable structural body supported by the beam,

a first stopper member supported by the substrate and arranged at a distance from the movable structural body in an in-plane direction with respect to the surface,

a second stopper member supported by the first stopper member and arranged at a distance from the movable structural body in an out-of-plane direction with respect to the surface,

a third stopper member supported by the first stopper member, arranged opposite to the second stopper member with the movable structural body interposed therebetween in the out-of-plane direction, and arranged at a distance from the movable structural body,

a first sacrificial film formed between the movable structural body and the first stopper member,

a second sacrificial film formed between the movable structural body and the second stopper member, and

a third sacrificial film formed between the movable structural body and the third stopper member; and

performing an etching process to remove the first sacrificial film, the second sacrificial film and the third sacrificial film, to form a first gap between the movable structural body and the first stopper member, form a second gap between the movable structural body and the second stopper member, and form a third gap between the movable structural body and the third stopper member.

5. The method of manufacturing a semiconductor device according to claim 4, wherein

the first stopper member and the third stopper member are simultaneously formed of an identical film.