A method of manufacturing a thermal-type infrared solid-state image sensing device that comprises, on a substrate:
- an image sensing section in which a plurality of light receiving elements that detect incident infrared rays are arranged in array, and
- a reference section in which at least one reference element which outputs a reference signal that is free from any influence of incident infrared rays is arranged;
- the light receiving element and the reference element comprising which comprises a thermoelectric conversion element and a supporting section which supports the light receiving section spaced apart from the substrate, and
- the supporting section composed of a structure interlaying between the substrate and the light receiving section, a first connecting portion which connects one end of the structure and the substrate, and a second connecting portion which connects the other end of the structure and the light receiving section, characterized in that
- at least, the method comprising the steps of:
- forming a first sacrifice layer on the substrate in which a signal read-out circuit is formed with the exception of the area on a terminal electrode of the signal read-out circuit with which the first connecting portion of the supporting section is to be connected;
- forming a first insulating film, an lower-layer metallic interconnect, and a second insulating film in the region which is used for construction of the first connecting portion and the structure of the supporting section;
- forming a second sacrifice layer in the region which is used for construction of the light receiving section;
- forming a third insulating film, an upper-layer metallic interconnect to be connected to the lower-layer metallic interconnect, a fourth insulating film, and a fifth insulating film in the region which is used for formation of the second connecting portion of the supporting section, and coincidentally, in the region which is used for construction of the light receiving section, forming also the third insulating film, the thermoelectric conversion element, the fourth insulating film, an upper-layer metallic interconnect to be connected with the end portion of the thermoelectric conversion element, the fourth insulating film and the fifth insulating film or alternatively forming the third insulating film, the upper-layer metallic interconnect, the fourth insulating film, the thermoelectric conversion element, and the fifth insulating film;
- forming the light receiving section of the reference potion by forming a first slit piercing through the third to fifth insulating films in the reference section, forming a film made of electrically conductive material at least on the light receiving section and the first slit of the reference section and thereafter forming a protective film at least on the first slit, thereby forming a structure in which the film made of electrically conductive material and the protective film cover a side wall and a bottom of the first slit and a void remains in the first slit;
- and
- forming the light receiving section of the image sensing section by forming a second slit piercing though the third to fifth insulating films or though the third to fifth insulating films and the protective film in the image sensing section and removing the first sacrifice layer and the second sacrifice layer of the image sensing section via the second slit,
- wherein a film made of a material having a relatively good step coverage is stacked on a film made of a material having a relatively bad step coverage to be used as the film made of electrically conductive material.