초록 ▼

A capacitive pressure sensor and its manufacturing method can simplify the alignment and the bonding process in a vacuum, and stably carry out the bonding process. The capacitive pressure sensor includes an insulating, first substrate with a capacitance electrode, a second substrate which has a diap

A capacitive pressure sensor and its manufacturing method can simplify the alignment and the bonding process in a vacuum, and stably carry out the bonding process. The capacitive pressure sensor includes an insulating, first substrate with a capacitance electrode, a second substrate which has a diaphragm electrode so as to separate a vacuum chamber and a pressure-measuring chamber on respective surfaces, and an insulating, third substrate with a gas inlet. The substrates are bonded in a manner that the capacitance electrode faces the diaphragm electrode and the pressure-measuring chamber leads to the gas inlet. In addition, a getter chamber is formed in the same surface of the second substrate as the pressure-measuring chamber, and the getter chamber is connected to the vacuum chamber.

대표청구항 ▼

1. A capacitive pressure sensor comprising:an insulating, first substrate with a capacitance electrode; a second substrate which has a diaphragm electrode which separates a vacuum chamber and a pressure-measuring chamber groove on respective surfaces; and an insulating, third substrate with a gas in

1. A capacitive pressure sensor comprising:an insulating, first substrate with a capacitance electrode; a second substrate which has a diaphragm electrode which separates a vacuum chamber and a pressure-measuring chamber groove on respective surfaces; and an insulating, third substrate with a gas inlet; said substrates being bonded in such a manner that said capacitance electrode faces said diaphragm electrode and said pressure-measuring chamber leads to said gas inlet; wherein a getter chamber is formed on a same surface of said second substrate as said pressure-measuring chamber, and the getter chamber is communicated with the vacuum chamber. 2. The capacitive pressure sensor according to claim 1, wherein said second substrate is an SOI (Silicon On Insulator) substrate composed of a silicon layer, a buried oxide layer and a base silicon layer, and said vacuum chamber is formed in said silicon layer, and said pressure-measuring chamber and getter chamber are formed in said base silicon layer.3. The capacitive pressure sensor according to claim 1, wherein a plurality of small projections of silicon oxide are formed on a surface of said capacitance electrode.4. The capacitive pressure sensor according to claim 2, wherein a plurality of small projections of silicon oxide are formed on a surface of said capacitance electrode.5. A manufacturing method for a capacitive pressure sensor in which an insulating, first substrate with a capacitance electrode; a second substrate being an SOI substrate including a silicon layer where a vacuum chamber and a diaphragm electrode are formed, a buried oxide layer, and a base silicon layer where a pressure-measuring chamber and a getter chamber are formed; and a third substrate with a gas inlet are bonded in such a manner that said capacitance electrode faces said diaphragm, and said pressure-measuring chamber leads to said gas inlet, the method comprising:bonding said first substrate on which said capacitance electrode is formed with said second substrate in which said vacuum chamber is formed by using an anodic bonding method; etching said base silicon layer to form said pressure-measuring chamber and said getter chamber; removing said buried oxide layer on said pressure-measuring chamber and said getter chamber by an etching technique; removing a part of said silicon layer located between said vacuum chamber and said getter chamber to connect said two chambers; and bonding said base silicon layer with said third substrate by using an anodic bonding method after a getter is placed in said getter chamber while the inside of said getter chamber is maintained at a vacuum. 6. The manufacturing method according to claim 5, wherein said capacitance electrode is comprised of silicon on which a plurality of small projections of silicon oxide are formed in such a manner that:the SOI substrate comprised of a silicon layer, a buried oxide layer, and a base silicon layer is prepared; said silicon layer and said buried oxide layer are etched and removed except the portion corresponding to said capacitance electrode; said silicon layer is bonded with an insulating substrate; said base silicon layer is etched and removed; and then said buried oxide layer is patterned to form said projections.