| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a physical quantity sensor capable of preventing a membrane from breaking because of becoming too thin. <P>SOLUTION: The buried layer of the SOI substrate (Silicon On Insulator) used for forming a thermal flowrate sensor is not only constituted with one layer of SiO<SB>2</SB>but also a silicon nitride membrane 11 arranged on the surface 10b of the silicon substrate 10. Thereby, at the time of etching the silicon substrate 10, the silicon nitrate membrane 11 is functioned as an etching stopper, therefore the silicon oxide membrane 12 is prevented from being eliminated. Thereby, the thinning of the membrane caused by the being etched of the silicon oxide membrane 12 can be prevented, and breakage caused by the too much thinning the membrane can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
