Dynamic quantity sensor device and manufacturing method of the same

A dynamic quantity sensor device comprising:

• a first dynamic quantity sensor for detecting pressure as a first dynamic quantity;
• a second dynamic quantity sensor for detecting a second dynamic quantity other than the pressure;
• a first substrate made of a SOI substrate having a support substrate, an embedded oxide film and a SOI layer, which are stacked in this order;
• and
• a second substrate,
• wherein the first dynamic quantity sensor and the second dynamic quantity sensor are integrated with each other,
• wherein the first dynamic quantity sensor includes a first dynamic quantity detecting unit, which is displaceable according to the pressure,
• wherein the second dynamic quantity sensor includes a second dynamic quantity detecting unit, which is displaceable according to the second dynamic quantity,
• wherein the first dynamic quantity detecting unit and the second dynamic quantity detecting unit are disposed on a principal surface of the first substrate,
• wherein the first dynamic quantity detecting unit is spaced apart from the second dynamic quantity detecting unit by a predetermined distance,
• wherein the second substrate is bonded to the principal surface of the first substrate so as to cover the first dynamic quantity detecting unit and the second dynamic quantity detecting unit,
• wherein the first substrate and the second substrate provide a first space and a second space,
• wherein the first dynamic quantity detecting unit is air-tightly accommodated in the first space, and the second dynamic quantity detecting unit is air-tightly accommodated in the second space,
• wherein the first space and the second space do not communicate with each other,
• wherein the SOI layer is divided into a plurality of semiconductor regions by a plurality of trenches so that the plurality of semiconductor regions are electrically isolated from each other,
• wherein each trench reaches the embedded oxide film,
• wherein a first part of the plurality of semiconductor regions provides the first dynamic quantity detecting unit,
• wherein a second part of the plurality of semiconductor regions provides the second dynamic quantity detecting unit,
• wherein the second part of the plurality of semiconductor regions includes:
• a second movable semiconductor region having a second movable electrode, which is displaceable and is provided by etching a part of the embedded oxide film as a sacrificial layer;
• and
• a second fixed semiconductor region having a second fixed electrode, which faces the second movable electrode,
• wherein the second movable electrode and the second fixed electrode provide a capacitor having a dielectric layer, which is provided by space between the second movable electrode and the second fixed electrode, and
• wherein the second dynamic quantity sensor detects the second dynamic quantity by measuring a capacitance of the capacitor, which is changeable in accordance with displacement of the second movable electrode when the second movable electrode is displaced in response to the second dynamic quantity applied to the second dynamic quantity sensor.