Radiation sensor with photodiodes being integrated on a semiconductor substrate and corresponding integration process

Integration process of a sensor with photodiodes being integrated in a multi-layer structure comprising a semiconductor substrate and a structure of alternating intermetal dielectric layers and metallic layers, as well as an upper passivation layer of the type comprising the steps of:

• making at least one first and one second pn junction, suitable for making at least one first and one second photodiode in said semiconductor substrate;
• removal of said intermetal dielectric layers and of said upper passivation layer at least one opening suitable for uncovering a surface of said semiconductor substrate at said junctions,
• deposition of a first antireflection dielectric layer covering at least said surface;
• and
• deposition on top of said first antireflection dielectric layer of a second antireflection dielectric layer to make a double layer antireflection coating suitable for obtaining a responsivity peak for the corresponding photodiode at a predetermined wavelength of an optical signal incident on said sensor.

An electronic device, comprising:

• a first p-n junction;
• a second p-n junction;
• a first antireflective coating disposed over the first junction;
• a second antireflective coating disposed over the second junction;
• and
• wherein at least one of the first and second antireflective coatings comprises a first antireflective layer having a first thickness and a second antireflective layer disposed over the first antireflective layer and having a second thickness that is different from the first thickness.

An integrated circuit, comprising:

• a first p-n junction;
• a second p-n junction;
• a first antireflective coating disposed over the first junction;
• a second antireflective coating disposed over the second junction;
• and
• wherein at least one of the first and second antireflective coatings comprises a first antireflective layer having a first thickness and a second antireflective layer disposed over the first antireflective layer and having a second thickness that is different from the first thickness.

A system, comprising:

• a first integrated circuit including:
• at least a first photodiode including a first p-n junction and a first antireflective coating disposed over the first junction,
• at least a second photodiode including a second p-n junction and a second antireflective coating disposed over the second junction, and
• wherein at least one of the first and second antireflective coatings comprises a first antireflective layer having a first thickness and a second antireflective layer disposed over the first antireflective layer and having a second thickness that is different from the first thickness;
• and
• a second integrated circuit coupled to the first integrated circuit.

A method, comprising:

• receiving a first wavelength of electromagnetic radiation through a first antireflective layer having a first thickness and through a second antireflective layer having a second thickness that is different than the first thickness;
• receiving a second wavelength of electromagnetic radiation through a third antireflective layer;
• generating a first signal across a first p-n junction in response to the received first wavelength;
• and
• generating a second signal across a second p-n junction in response to the received second wavelength.