Patent ID: 7178400
Filing Date: 2007-02-20
Classification: G01C,G01P

Abstract:
1. A semiconductor physical quantity sensor comprising: a substrate; a semiconductor layer supported on the substrate; a trench disposed in the semiconductor layer; and a movable portion disposed in the semiconductor layer and separated from the substrate by the trench, wherein the movable portion includes a plurality of through-holes, each of which penetrates the semiconductor layer in a thickness direction, the movable portion is capable of displacing on the basis of a physical quantity applied to the movable portion so that the physical quantity is detected by a displacement of the movable portion, the movable portion includes a center portion and a periphery portion, the movable portion has a plurality of junctions disposed among the through-holes, each of the plurality of junctions has a trifurcate shape at least in the center portion, the movable portion provides a through-hole frame including a plurality of rods, each of the plurality of junctions being formed by an intersection of a number of the plurality of rods, each of the plurality of rods having a width in a horizontal direction perpendicular to a thickness direction, and a distance between a center of each of the plurality of junctions and a corner of a neighboring trench is smaller than (√{square root over (2)}/2) tunes the width of each of the plurality of rods.