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US 8,643,927 B2Granted
MEMS device and method of manufacturing MEMS device
AssigneeHitachi, Ltd.
InventorsChisaki Takubo, Heewon Jeong
Life of this patent
Estimating the term…
Abstract
A protrusion formation hole is provided so as to pierce a support substrate. A polysilicon film as an electrical conducting material is embedded in the protrusion formation hole through an oxide silicon film. The polysilicon film partially bulges out of the protrusion formation hole toward a movable section to form a protruding section. In other words, the polysilicon film bulges out of the protrusion formation hole toward the movable section to form the protruding section. Thereby, a movable section included in MEMS can be prevented from sticking to other members.
Claims16
A MEMS device manufacturing method comprising the steps of:
- (a) providing an SOI substrate including a support substrate, an intermediate insulation layer formed on the support substrate, and an active layer formed on the intermediate insulation layer;
- (b) following the step (a) and forming a protrusion formation hole in a movable section formation region of the SOI substrate so as to pierce the support substrate and expose the intermediate insulation layer;
- (c) following the step (b) and removing the intermediate insulation layer exposed from the protrusion formation hole to expose the active layer from the protrusion formation hole;
- (d) following the step (c) and oxidizing the active layer exposed from the protrusion formation hole and an inner wall of the protrusion formation hole to forma first oxidation layer on a surface of the active layer and the inner wall of the protrusion formation hole;
- (e) following the step (d) and embedding a conductive film in the protrusion formation hole;
- (f) following the step (e) and patterning the active layer of the SOI substrate to form an elastic deformation section of a MEMS sensor, a movable section connected to one end of the elastic deformation section, and an unmovable section connected to the other end of the elastic deformation section;
- (g) following the step (f), removing the intermediate insulation layer from the movable section formation region forming the movable section and the elastic deformation section formation region forming the elastic deformation section to suspend the movable section using the elastic deformation section, partially exposing the conductive film embedded in the protrusion formation hole to form a protruding section including part of the conductive film, and removing the first oxidation layer in contact with the protruding section to form a gap between the protruding section and the movable section.
4 more elements
A MEMS device manufacturing method comprising the steps of:
- (a) providing an SOI substrate including a support substrate, an intermediate insulation layer formed on the support substrate, and an active layer formed on the intermediate insulation layer;
- (b) following the step (a) and forming a plurality of protrusion formation holes in a movable section formation region of the SOI substrate so as to pierce the support substrate and expose the intermediate insulation layer;
- (c) following the step (b) and removing the intermediate insulation layer exposed from the protrusion formation holes to expose the active layer from the protrusion formation holes;
- (d) following the step (c) and oxidizing the active layer exposed from the protrusion formation holes and inner walls of the protrusion formation holes to form a first oxidation layer on a surface of the active layer and the inner walls of the protrusion formation hole;
- (e) following the step (d) and embedding a conductive film in the protrusion formation holes;
- (f) following the step (e) and patterning the active layer of the SOI substrate to form an elastic deformation section of a MEMS sensor, a movable section connected to one end of the elastic deformation section, and an unmovable section connected to the other end of the elastic deformation section;
- (g) following the step (f), removing the intermediate insulation layer from the movable section formation region forming the movable section and the elastic deformation section formation region forming the elastic deformation section to suspend the movable section using the elastic deformation section, partially exposing the conductive film embedded in the protrusion formation holes to form a plurality of protruding sections including part of the conductive film, and removing the first oxidation layer in contact with the protruding sections to form a gap between the protruding sections and the movable section;
- and
- wherein the step (b) forms the protrusion formation holes for surrounding a first region of the support substrate formed on the SOI substrate in order to electrically separate the first region from a second region of the support substrate formed on the SOI substrate.
6 more elements
A MEMS device comprising:
- (a) an SOI substrate including a support substrate, intermediate insulation layer portions disposed on the support substrate, and an active layer having portions disposed on the intermediate insulation layer portions;
- (b) an elastic deformation section having a first portion of the active layer spaced from the support substrate;
- (c) a movable section having a second portion of the active layer spaced from the support substrate, and being connected to one end of the elastic deformation section;
- (d) an unmovable section having a third portion of the active layer and being fixed to the support substrate through a portion of the intermediate insulation layer below the third portion of the active layer, and being connected to the other end of the elastic deformation section;
- and
- (e) a stopper section arranged so as to prevent the movable section from sticking to the support substrate.
3 more elements
Dependencies are inferred from the claim text.