Infrared sensor unit and process of fabricating the same

A process of fabricating an infrared sensor unit comprising the steps of:

• forming a semiconductor device in a top surface of a semiconductor substrate;
• forming a dielectric top layer on the top surface of said semiconductor substrate to conceal said semiconductor device therebehind;
• forming a pair of terminal pads on said dielectric top layer;
• laminating a sacrifice layer on said dielectric layer while leaving through-holes in said sacrifice layer, each of said through-holes leading to said each of said terminal pads;
• superimposing a porous material on top of said sacrifice layer to form a porous layer and filling said through-holes with said porous material;
• etching out a portion of said porous layer to give a thermal insulation structure of a predetermined pattern,
• forming a thermal infrared sensor on said thermal insulation structure;
• and
• removing said sacrifice layer;
• wherein said thermal insulation structure comprises a pair of posts formed by said porous material filled in said through-holes, a sensor mount carrying said thermal infrared sensor, and a pair of horizontal beams each extending in a parallel relation with the top surface of said dielectric top layer from each of said posts to said sensor mount, and wherein
• a patterned strip or wirings are deposited on said sensor mount as well as said horizontal beams and into via-holes in said posts to extend along each of said horizontal beams from said infrared sensor to each of said terminal pads through each of said posts,
• said sensor mount being supported above said semiconductor device through said horizontal beams by removal of said sacrifice layer.