| 摘要 |
PURPOSE:To measure a solution for a long time by providing a through hole in the recessed part of the first conductive type semiconductor substrate and forming the second conductive type source and drain area on both faces of the substrate, and forming an insulating film on both faces of the substrate including the inside face of the through hole. CONSTITUTION:A through hole 33 is provided in the recessed part of a p-type silicon substrate 31, and n<+> type source and drain areas 34 and 35 are formed on both faces of the substrate 31. An insulating film 37 is formed on both faces of the substrate 31 including the inside wall of the hole 33. A part of the insulat ing film 37 on the source area 34 and a p<+> type diffused layer 36 or on the drain area 35 is etched selectively to from contact pads 38 and 39. Lead wires 40 and 41 are connected to these pads 38 and 39. Consequently, connection parts between source and drain areas 34 and 35 and lead wires 40 and 41 are on the outside of a tube and are not immersed in the solution. It is unnecessary to coat connection parts with a resin therefore. Thus, insulation defects or the like due to swelling of the resin are not caused, and the solution is measured stably for a long time. |
