Thermal type air flow sensor

摘要

A thermal type air flow rate sensor (1) is formed with at least a heating resistor (4a, 4b) and a temperature measuring resistor (5) on a semiconductor substrate (2) via an electric insulation film (12a), by forming the heating resistor (4a, 4b) and the temperature measuring resistor (5) with an impurity doped silicon (Si) semiconductor thin film (13), and by performing high concentration doping process so that an electric resistivity ( rho ) of the silicon (Si) semiconductor thin film (13) is less than or equal to 8 x 10<-4> OMEGA cm, with simplified fabrication process for formation of the silicon (Si) semiconductor thin film (13) at the same impurity concentration simultaneously in a lump at low cost. <IMAGE>