Flow sensor with metal film resistor

摘要

The present, invention provides a technology capable of achieving a highly-sensitive flow sensor, by forming a metal film having a relatively high TCR on a semiconductor substrate via an insulating film. A measurement device which is a thermal fluid flow sensor includes a heat element, resistance temperature detectors (upstream-side resistance temperature detector and downstream-side resistance temperature detector), and a resistance temperature detector for air which are all formed of a first metal film. The first metal film may be formed of a Mo film having a resistivity lower than three times the resistivity of a Mo ingot and obtained by deposition through sputtering on an amorphous film containing metal.
Alternatively, a metal film may be deposited on an insulated film which has been treated by sputter-etching or ion implantation.
The metal film should have a large proportion of crystal grains with a diameter larger than 100 nm.