Acceleration sensor and method for manufacturing the same

An acceleration sensor comprising:

• a semiconductor substrate including a support layer and a semiconductor layer, which are stacked in a first direction perpendicular to the semiconductor substrate;
• a movable electrode and a fixed electrode disposed in the semiconductor layer;
• and
• a trench disposed on the semiconductor layer and reaching the support layer, wherein
• the movable electrode separately faces the fixed electrode by sandwiching the trench along with a second direction, which is parallel to the semiconductor substrate,
• the trench has a detection distance in the second direction,
• the movable electrode is movable along with the first direction when acceleration is applied to the semiconductor substrate along with the first direction so that the acceleration is detected on the basis of capacitance change of a capacitor between the movable electrode and the fixed electrode,
• the movable electrode has a bottom, which faces the support layer and is apart from the support layer,
• the movable electrode has a width along with the second direction, and the fixed electrode has a width along with the second direction,
• the width of the movable electrode is smaller than the width of the fixed electrode,
• the movable electrode has a thickness along with the first direction, and the fixed electrode has a width along with the first direction, and
• the thickness of the movable electrode is smaller than the thickness of the fixed electrode.