Photodetection device and method for manufacturing photodetection device

A method of manufacturing a photodetection device, the method comprising:

• preparing a light-receiving element including a first main surface including an arrangement of a plurality of first electrodes;
• forming a first bump containing indium on each of the plurality of first electrodes;
• preparing a circuit substrate including a second main surface including an arrangement of a plurality of second electrodes;
• forming a second bump containing indium on each of the plurality of second electrodes;
• sputtering a first oxide containing indium to form a first deformation suppressing oxide film on at least one of a surface of the first bump or a surface of the second bump;
• aligning, to suppress short circuits, the first bump and the second bump on top of each other with the first deformation suppressing oxide film therebetween by placing the first main surface and the second main surface so as to face each other;
• and
• bonding together the first bump and the second bump to form a conductive connection portion under reduction of the first deformation suppressing oxide film by heat treating in a reducing atmosphere.