Capacitance type transducer and method of manufacturing the same
A capacitance type transducer includes a plurality of cells each having a structure in which a vibrating film is supposed so as to be vibrated. The vibrating film includes: a second electrode formed so that a gap is interposed between the second electrode and a first electrode; and an insulating film formed on the second electrode. The capacitance transducer manufacturing method includes: forming a sacrificial layer on the first electrode; forming a layer including a vibrating film on the sacrificial layer; forming an etching hole to remove the sacrificial layer; and forming a sealing film for sealing the etching hole. Before forming the etching hole to remove the sacrificial layer, a through hole is formed in an insulating film on the second electrode, and a conductor film is formed on the insulating film having the through hole to electrically connect a conductor in the through hole and the second electrode.
1. A method of manufacturing a capacitance type transducer comprising a plurality of cells each having a structure in which a vibrating film is supported so as to be vibrated, the vibrating film comprising: a second electrode formed so that a gap is interposed between the second electrode and a first electrode; and an insulating film formed on the second electrode,
the method comprising:
forming a sacrificial layer on the first electrode;
forming a layer including the vibrating film on the sacrificial layer;
forming an etching hole to remove the sacrificial layer; and
forming a sealing film configured to seal the etching hole,
the method further comprising, before the forming an etching hole to remove the sacrificial layer:
forming a through hole in the insulating film on the second electrode; and
forming a conductor film on the insulating film including the through hole to electrically connect a conductor in the through hole and the second electrode to each other,
wherein the conductor film electrically connects second electrodes of the plurality of cells to each other.
2. The method according to claim 1 , further comprising:
removing, with use of the conductor film as an etch stop film, at least a part of a portion overlapping the gap in an orthographic projection of the sealing film onto the first electrode side up to a surface of the etch stop film after forming the sealing film; and
patterning the etch stop film to form wiring configured to electrically connect the second electrodes in at least a part of the plurality of cells.
3. The method according to claim 1 , further comprising patterning the conductor film to form wiring configured to electrically connect the second electrodes in at least a part of the plurality of cells before the forming a sealing film configured to seal the etching hole.
4. The method according to claim 1 , wherein the sealing film and the insulating film on the second electrode are formed of the same material.
5. The method according to claim 4 , wherein the same material comprises silicon nitride.
6. The method according to claim 1 , wherein the conductor film comprises one of a titanium film, a stacked film including a titanium layer, an aluminum film, a stacked film including an aluminum layer, and an alloy film containing at least one of titanium or aluminum.