Sensor device integrated with ultrasonic transducer and microphone and manufacturing method thereof

A manufacturing method for a sensor device integrated with an ultrasonic transducer and a microphone, the method comprising the steps of:

• preparing a substrate having a first region and a second region;
• forming a first support structure on the first region;
• forming a back plate on the first support structure, wherein
• the back plate extends above the second region;
• a pressure relief gap is formed between the back plate and the second region;
• the back plate has an electrode-forming region above the first region of the substrate and multiple sound holes above the second region of the substrate;
• and
• the sound holes communicate with the pressure relief gap;
• forming a first electrode on the electrode-forming region of the back plate and forming a second electrode on the back plate above the second region of the substrate;
• forming a second support structure on the back plate, wherein the second support structure has a first opening and a second opening, the first electrode and the second electrode are respectively exposed from the first opening and the second opening;
• forming a membrane on the back plate to cover the first opening and the second opening;
• and
• forming a third electrode and a fourth electrode on the membrane, wherein the third electrode is above the first electrode, and the fourth electrode is above the second electrode;
• wherein the first electrode, the third electrode, a part of the back plate, a part of the second support structure and a part of the membrane that are above the first region of the substrate collectively form the ultrasonic transducer;
• and
• wherein the first support structure, the second electrode, the fourth electrode, a part of the back plate, a part of the second support structure and a part of the membrane that are above the second region of the substrate collectively form the microphone.