Physical sensor

A physical sensor for detecting a physical quantity comprising:

• a substrate including a silicon layer, an oxide film and a support layer, which are stacked in this order, wherein the silicon layer includes a lower layer, an insulation film and an upper layer, and the lower layer is disposed on the oxide film;
• and
• a sensor portion includes a movable portion, a fixed portion and a lower electrode, wherein the movable portion and the fixed portion are disposed in the upper layer of the silicon layer, the movable portion includes a movable electrode, which is supported by a beam on the support layer, the fixed portion includes a fixed electrode facing the movable electrode, the lower electrode is disposed on the support layer, and the lower electrode faces the movable electrode via a space without the oxide film,
• wherein the physical sensor detects the physical quantity along with a first direction parallel to the substrate based on a capacitance between the movable electrode and the fixed electrode,
• wherein the physical sensor detects the physical quantity along with a second direction perpendicularly to the substrate based on a capacitance between the movable electrode and the lower electrode,
• wherein the beam includes a vertical beam displaceable along with the second direction and a horizontal beam displaceable along with the first direction,
• wherein the vertical beam has a thickness in the second direction, and the horizontal beam has a thickness in the second direction, and
• wherein the thickness of the vertical beam is smaller than the thickness of the horizontal beam.

A physical sensor for detecting a physical quantity comprising:

• a substrate including a silicon layer, an oxide film and a support layer, which are stacked in this order;
• and
• a sensor portion including a movable portion, a fixed portion and an upper electrode, wherein the movable portion and the fixed portion are disposed in the silicon layer, the movable portion includes a movable electrode, which is supported by a beam on the support layer, the fixed portion includes a fixed electrode facing the movable electrode, the upper electrode is spaced apart from the movable electrode by a predetermined distance, and the upper electrode is disposed opposite to the support layer,
• wherein the physical sensor detects the physical quantity along with a first direction parallel to the substrate based on a capacitance between the movable electrode and the fixed electrode,
• wherein the physical sensor detects the physical quantity along with a second direction perpendicularly to the substrate based on a capacitance between the movable electrode and the upper electrode,
• wherein the beam includes a vertical beam displaceable along with the second direction and a horizontal beam displaceable along with the first direction,
• wherein the vertical beam has a thickness in the second direction, and the horizontal beam has a thickness in the second direction, and
• wherein the thickness of the vertical beam is smaller than the thickness of the horizontal beam.