| 摘要 |
PURPOSE:To facilitate the manufacture of a pH sensor, by providing silicon oxide deposited layer as a pH sensitive layer on a gate insulation layer of an EFT. CONSTITUTION:A silicon oxide deposited film is formed on a silicon dioxide gate insulation layer over a p-type silicon substrate in which two n-type regions are formed on a surface portion thereof as source and drain of an EFT. In the formation of the silicon oxide deposited film, SiO is used at a temperature of 10-50 deg.C for the substrate and a temperature of above 170 deg.C for a tungsten board and the operation is performed with vacuum of about 5X10<-5>-5X10<-4>Torr at the evaporation. Thus, the film is formed as evaporated film with a thickness of about 500-10,000Angstrom . Thereafter, processes are performed from the making of a contact hole by a plasma etching down to a wire bonding to manufacture a pH sensor and a gate metal portion is removed to form a pH sensitive layer in place. |
