US 6,388,300 B1 · Semiconductor physical quantity sensor and method of manufacturing the same

Abstract

A semiconductor physical quantity sensor, in which a beam-structure having a movable electrode and a fixed electrode confronted with the movable electrode are integrally formed in one substrate, having a new electric isolation structure. A semiconductor physical quantity sensor such as an acceleration sensor includes a silicon substrate; a laterally extending hollow formed in the silicon substrate; and a base plate portion defined below the hollow in the silicon substrate. A rectangular frame portion, a beam-structure having a movable electrode, and a fixed electrode is defined by the hollow and trenches. The fixed electrode confronts with the movable electrodes of the beam-structure. Trenches, in which electrical insulating material is buried, are formed between the movable electrode and the rectangular frame portion and between the fixed electrodes and the rectangular frame portion.

Claims18

Dependent claims

A semiconductor physical quantity sensor comprising:

a substrate including a semiconductor layer, the semiconductor layer having therein a hollow being laterally extended;
a frame portion being provided to the semiconductor layer;
a beam-structure being arranged above the hollow, being connected to the frame portion, and having a movable electrode movable by action of physical quantity;
a fixed electrode being connected to the frame portion, confronting with the movable electrode, and being disposed on the hollow, the fixed electrode is made of a same material as the semiconductor layer to serve as a conductive member;
and
at least one insulator provide between the frame portion and the fixed electrode, for electrically insulating the frame portion from the fixed electrode,
wherein the insulator reaches he hollow so that whole of the fixed electrode is disposed on the hollow, whereby the fixed electrode is hung up the frame portion through the insulator so as to be supported by the frame portion through the insulator.

4 more elements

A semiconductor physical quantity sensor comprising:

an SOI substrate having a support substrate and the semiconductor layer with a buried insulating film interposed therebetween, the support substrate having a primary hollow being laterally extended, the buried insulating film having a through hole, the semiconductor layer having a trench and a secondary trench being vertically extended, the semiconductor layer having a hollow and a secondary hollow being laterally extended, and the semiconductor layer and the primary hollow having primary trench being vertically extended;
a primary frame portion being divided by the primary hollow and the through hole, and being positioned at sides of the primary hollow, the primary trench and the through hole;
a primary oscillatory mass being divided by the primary hollow, the primary trench and the through hole, being connected to the primary frame portion, and having a primary movable electrode;
a primary excitation fixed electrode being divided by the hollow and the trench formed in the semiconductor layer, being connected to the primary frame portion, and confronting -with the primary movable electrode;
a secondary frame portion being divided by the secondary hollow and the secondary trench, and being positioned at sides of the both the secondary hollow and the secondary trench, for supporting the primary movable electrode of the primary oscillatory mass;
a beam-structure being divided by the secondary hollow and the secondary trench, being positioned above the secondary , being connected to the secondary frame portion, and having a secondary movable electrode movable by action of physical quantity;
a secondary excitation fixed electrode being divided by the secondary hollow and the secondary trench, being positioned above the secondary hollow, being connected to the secondary frame portion, and confronting with the secondary movable electrode;
a first insulator being buried in insulating trenches provided between the primary movable electrode and the second frame portion, and between the primary excitation fixed electrode and the primary frame port on;
and
a second insulator being buried in insulating trenches provided between the secondary movable electrode and the secondary frame portion, and between the secondary excitation fixed electrode and the secondary frame portion,
wherein the primary hollow communicates with the hollow and the secondary hollow formed in the semiconductor layer through the hole formed in the buried insulating film.

8 more elements

Dependencies are inferred from the claim text.

Semiconductor physical quantity sensor and method of manufacturing the same

Life of this patent

Semiconductor physical quantity sensor and method of manufacturing the same

Life of this patent

Abstract

Claims18