On-chip screen type solid state image sensor and manufacturing method thereof

A method for manufacturing a solid state image sensor comprising the steps of:

• forming a photodiode and a vertical CCD in a matrix form on a semiconductor substrate;
• forming a transfer gate electrode on the vertical CCD on the semiconductor substrate via an insulating film;
• forming a light-shielding film on the transfer gate electrode;
• forming an underlying smooth layer for smoothing the semiconductor substrate surface;
• forming a first light-shielding layer on the underlying smooth layer on the transfer gate electrode;
• forming a first transparent film on the first light-shielding layer and smoothing the first transparent film;
• forming a second light-shielding layer on the first transparent film;
• and
• forming a second transparent film on the second light-shielding layer and smoothing the second transparent film.

A method for manufacturing a solid state image sensor comprising the steps of:

• forming a photodiode and a vertical CCD in a matrix form on a semiconductor substrate;
• forming a transfer gate electrode on the vertical CCD on the semiconductor substrate via an insulating film;
• forming a light-shielding film on the transfer gate electrode;
• forming an underlying smooth layer for smoothing the semiconductor substrate surface;
• forming a first light-shielding layer on the underlying smooth layer on the transfer gate electrode;
• forming a first transparent film on the first light-shielding layer and smoothing the first transparent film;
• forming a second light-shielding layer on the first transparent film;
• forming a second transparent film on the second light-shielding layer and smoothing the second transparent film;
• forming a third light-shielding layer on the second transparent film;
• forming a third transparent film on the third light-shielding layer and smoothing the third transparent film;
• and forming a micro lens on the third transparent film.

An on-chip filter type solid state image sensor comprising:

• a semiconductor substrate;
• a photodiode disposed on the semiconductor substrate for photoelectric conversion into electric charges by incoming light;
• a transfer electrode disposed on the semiconductor substrate for transmission of the electric charges from the photodiode;
• a light-shielding layer disposed to cover the transfer electrode and shield the transfer electrode against the incoming light;
• a smooth layer disposed on the light-shielding layer;
• a micro lens disposed above the smooth layer for collecting the incoming light;
• and
• two or more light-shielding layers disposed between the smooth layer and the micro lens and arranged along an optical path of the incoming light traveling from the micro lens to the photodiode and located outside the optical path of the incoming light on the photodiode, for shielding the incoming light reflected from the transfer electrode.