Semiconductor device and manufacturing method of the same

A semiconductor device comprising:

• a first semiconductor chip that includes:
• a first substrate;
• an insulating layer formed on an upper surface of the first substrate;
• an optical waveguide formed on the insulating layer;
• an interlayer insulating film formed over the insulating layer so as to cover the optical waveguide;
• and
• a concave portion formed in a region of the first substrate different from a region in which the optical waveguide is formed,
• wherein the concave portion penetrates into the first substrate through the interlayer insulating film and the insulating layer;
• and
• a second semiconductor chip that includes a second substrate, and a light emitting unit formed on an upper surface of the second substrate and emitting a light toward the optical waveguide,
• wherein the second semiconductor chip is mounted in the concave portion, and
• wherein a pedestal which is an insulating film is formed between a bottom surface of the concave portion and a back surface of the second substrate, the back surface being a surface opposite to the upper surface of the second substrate.