Photoelectric conversion device and imaging system

A photoelectric conversion device comprising:

• a photoelectric conversion part provided in a semiconductor substrate;
• a signal generation part configured to generate an electrical signal based on a signal charge generated by the photoelectric conversion part;
• and
• a transfer gate configured to transfer a signal charge to the signal generation part from the photoelectric conversion part;
• and
• a continuous film configured to cover the photoelectric conversion part, and to cover a top surface of a gate electrode of the transfer gate,
• wherein a first region is provided between the continuous film and the photoelectric conversion part, the first region being configured to have a refractive index lower than refractive indices of the continuous film and the photoelectric conversion part, and to form an interface boundary with the continuous film, and
• wherein a second region is provided between the continuous film and the top surface of the gate electrode, the second region being configured to have a refractive index lower than refractive indices of the gate electrode and the continuous film, and to form an interface boundary with the continuous film, and
• wherein T2 is greater than T1 and less than λ/2−T1 where an optical thickness of the first region is T1, an optical thickness of the second region T2, and a wavelength of an incident light entering the photoelectric conversion part is λ.