| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable removal of an electrode from the back surface side of a substrate and prevent the contamination, damages to a membrane, etc., during manufacturing process. SOLUTION: An electrically insulating cylindrical region that is continuous from the front surface to the back surface of the substrate, but closed in the in-plane direction is formed inside a circuit board 22, comprising a semiconductor substrate. The electrically insulated region is formed an insulating layer 33 comprising heatproof insulating material. The insulating layer 33 is formed by forming a through-hole or a groove in the circuit board 22, then forming an oxide film or a nitride film on the wall surface or filling insulating material. In case of forming a groove, after a film has been formed on the insulating layer 33, the substrate is made thinner by grinding, etc., until the groove appears on the front and back surfaces of the substrate. The region surrounded by the insulating layer 33 functions as an electrode 31 by increasing electrical conductivity by diffusion of impurities.</p> |
