| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of producing a thermal type flow sensor capable of abolishing a level difference of semiconductor layer configuring heaters and preventing degradation of sensor properties. <P>SOLUTION: A part except for a division comprising heater pattern out of SOI layers in the SOI substrate used for formation of a thermal type flow sensor S1 is selectively oxidized to form silicon oxide film 13 around the heater pattern. In other words, the silicon oxide film 13 of almost same thickness as the heater pattern is placed around the heaters 15a and 15b corresponding to the heater pattern, the thermometers 16a and 16b measuring ambient temperature and the wiring layers 17a to 17f. Thereby, the level difference of the heater pattern can be abolished and causes of degradation of sensor properties become possible to abolish, resulting from adhesion of contaminated material at the level difference divisions and emergence of peeling due to collision by a foregin matter. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
