Micro gas sensor and manufacturing method thereof

A method of manufacturing a micro gas sensor comprising:

• forming an insulating layer on a substrate;
• coating a photoresist on the insulating layer and performing patterning on the insulating layer by using one pattern mask;
• forming a silicon trench structure from a surface of an exposed substrate to a predetermined depth by performing anisotropic etching on the exposed substrate in a vertical direction by using the patterned insulating layer as an etching masking layer;
• simultaneously forming an open cavity, the electrode pad separation grooves, the die separation lines, a micro heater pattern including an insulating layer suspended on the open cavity, and a plurality of sensing electrode patterns by performing isotropic etching on the substrate having the silicon trench structure;
• simultaneously forming a micro heater, a plurality of sensing electrodes, and a plurality of electrode pads on the same plane by depositing a conductive layer on the insulating layer;
• and
• forming a gas sensing film so that the gas sensing film is not contacted to a lower portion of the substrate by capillary force and surface tension and is contacted to surfaces of the micro heater and a plurality of the sensing electrodes by dropping a liquid precursor between microelectrode finger spacings formed by a plurality of the sensing electrodes.