Detector for use in infrared analyzer, flow detector and manufacturing method thereof

Abstract

A detector,for use in infrared gas analyzers has two compartments,and,to be filled with gas G showing the same absorption characteristics as the gas to be measured and which are arranged in series with a load cell,and the gas compartments,and,communicate with each other via a gas channel,in which a pyroelectric flow detector element,is provided. Pyroelectric flow detector element B is produced by a process which includes the steps of forming a lower electrode,on a substrate,forming a thin ferroelectric film,on the lower electrode, forming an upper electrode,on the thin ferroelectric film, patterning the upper electrode, the thin ferroelectric film and the lower electrode in that order by photolithography, with gas passage holes,being also formed, thereafter forming a thin insulator film,that covers a pyroelectric sensing portion,that is composed of the upper electrode, the thin ferroelectric film and the lower electrode, with gas passage holes and contact holes,and,being also formed in said thin insulator film, forming a heating electrode film on the thin insulator film, patterning the heating electrode film by photolithography, allowing a portion of the heating electrode film to drop in the contact holes to make lead-ins for the upper and lower electrodes, and etching away that part of the substrate which is just under the pyroelectric sensing portion to form an opening