Photodetection device and method for manufacturing photodetection device
A method of manufacturing a photodetection device, the method includes preparing a light-receiving element including a first main surface including an arrangement of a plurality of first electrodes, forming a first bump containing In 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 In on each of the plurality of second electrodes, forming, at at least one of a surface of the first bump or a surface of the second bump, a first oxide film containing In, placing the first main surface and the second main surface so as to face each other, and placing the first bump and the second bump on top of each other with the first oxide film therebetween.
1 . 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.
2 . The method according to claim 1 , wherein the first deformation suppressing oxide film is formed at least on the surface of the first bump.
3 . The method according to claim 1 , wherein the first deformation suppressing oxide film is formed on both of the surface of the first bump and the surface of the second bump.
4 . The method according to claim 1 , wherein the first deformation suppressing oxide film has a thickness of 1 nm or more.
5 . The method according to claim 1 , wherein the reducing atmosphere includes formic acid.
6 . The method according to claim 1 , the method further comprising forming, at a surface of the conductive connection portion, a second oxide film containing indium.
7 . The method according to claim 6 , wherein the second oxide film has a thickness of 1 nm or more.
8 . A photodetection device comprising:
a light-receiving element including a first main surface including an arrangement of a plurality of first electrodes, wherein each of the plurality of the first electrodes includes a first bump containing indium;
a circuit substrate including a second main surface facing the first main surface and including an arrangement of a plurality of second electrodes, wherein each of the plurality of the second electrodes includes a second bump containing indium;
a first deformation suppressing oxide film containing indium on at least one of a surface of the first bump or a surface of the second bump, wherein the first deformation suppressing oxide film is formed by sputtering a first oxide containing indium; and
a conductive connection portion formed by bonding together the first bump and the second bump under reduction of the first deformation suppressing oxide film by heat treating in a reducing atmosphere, where the first bump and the second bump are aligned to suppress short circuits on top of each other with the first deformation suppressing oxide film therebetween.
9 . The method according to claim 1 , wherein the first deformation suppressing oxide film is formed at a rate of 0.13 nm/sec to 0.23 nm/sec.
10 . The method according to claim 1 , wherein the first oxide containing indium comprises indium oxide (In 2 O 3 ).
11 . The method according to claim 10 , wherein the first deformation suppressing oxide film comprises indium oxide (In 2 O 3 ).
12 . The method according to claim 1 , wherein the first bump comprises a Mohs hardness of approximately 1.2.
13 . The method according to claim 12 , wherein the first deformation suppressing film comprises a Mohs hardness of approximately 5.