Semiconductor pressure sensor

Abstract

Abstract PURPOSE:To detect the pressure difference between an insulating single crystal substrate side a polysilicon thin film side by the variation in the resistance induced by a strain by forming the polysilicon thin film on an insulating film on the insulating single crystal substrate or on a semiconductor substrate. CONSTITUTION:An SiO2 film 2 is formed on the (001) plane of an Si single crystal substrate 1, and a polysilicon thin film 3 is formed in an island. A gate oxidized film 4 is formed by oxidation, polysilicon 5 is superposed, is plasma etched, and a gate region is formed. It is treated in a POCl3 atmosphere to form an N type source 6, a drain 7 and a gate electrode 5. An SiO2 film 8 is covered, a window 9 is opened, an aluminum electrode is attached, and is annealed. With this structure, a sensor having temperature dependency smaller than the conventional one can be obtained, the irregularity between the lot or wafer can be managed only by controlling the thickness of the polysilicon thin film, and the dependency in the variation of the temperature characteritics can be almost eliminated.

Inventors

• 👤 Shinji Onga
• 👤 Kazumichi Omura

Bibliographic Details