Optical Signal Processing Apparatus and Manufacturing Method Thereof

A method for manufacturing an optical signal processing device, comprising the steps of:

• forming a first silica film on a front surface of a first silicon substrate;
• laminating the first silicon substrate on another second silicon substrate with a first silica film surface on a lamination side;
• grinding/polishing a back surface of the laminated first silicon substrate;
• and
• forming an under clad using thermal oxidation silica obtained by thermal oxidation of a silicon layer at the back surface of the first silicon substrate that was ground/polished.

A method for manufacturing an optical signal processing device, comprising the steps of:

• forming a silica film on a front surface of a first silicon substrate;
• forming a thermal oxidation silica film on a front surface of a second silicon substrate;
• laminating the silica film of the first silicon substrate and the thermal oxidation silica film of the second silicon substrate on each other;
• and
• grinding/polishing a back surface of the second silicon substrate until the thermal oxidation silica film is exposed, and forming an under clad using thermal oxidation silica.