Array of Geiger-mode avalanche photodiodes for detecting infrared radiation

1. An optoelectronic device, comprising:

a first array of Geiger-mode avalanche photodiodes formed in a die; and

a packaging structure, which includes:

a first external dielectric region formed by a first material configured to absorb secondary photons from the photodiodes in a first wavelength range and transmit radiation having a wavelength that falls in a pass-band with a second wavelength range that is higher than the first wavelength range, at least part of said pass-band including infrared wavelengths; and

an internal dielectric structure positioned between the first array and the first external dielectric region and formed by one or more second materials that substantially transmit radiation having a wavelength that falls in either of said first and second wavelength ranges.

2. The optoelectronic device according to claim 1 , wherein said internal dielectric structure comprises a first layer made of an epoxy resin and arranged on the die.

3. The optoelectronic device according to claim 2 , wherein the first layer surrounds the die laterally.

4. The optoelectronic device according to claim 2 , wherein said internal dielectric structure comprises a second layer that bonds the first layer and the first external dielectric region together.

5. The optoelectronic device according to claim 1 , wherein said first external dielectric region is made of a polymeric plastic material.

6. The optoelectronic device according to claim 5 , wherein said first external dielectric region is made of allyl diglycol carbonate or polyallyl diglycol carbonate.

7. The optoelectronic device according to claim 1 , wherein said die comprises a semiconductor body having a front surface and including a cathode region of a first type of conductivity; and wherein each photodiode comprises:

a respective anode region of a second type of conductivity, which extends within the cathode region;

a lateral insulation region extending through the body starting from the front surface and surrounding the respective anode region and a corresponding part of the cathode region, said lateral insulation region including a barrier region and an insulating region, which surrounds the barrier region, said barrier region being configured to absorb or reflect radiation.

8. The optoelectronic device according to claim 7 , wherein said anode region extends into the semiconductor body from the front surface.

9. The optoelectronic device according to claim 7 , wherein said die comprises a passivation region, which extends over the front surface, in contact with the semiconductor body; and wherein said internal dielectric structure extends in contact with said passivation region.

10. The optoelectronic device according to claim 9 , wherein said passivation region has a refractive index, which, in said stop-band and in said pass-band, falls in an interval.

11. The optoelectronic device according to claim 1 , further comprising:

a second array of Geiger-mode avalanche photodiodes; and

a second external dielectric region overlying said second array and made of a third material having a different pass-band than the first material.

12. The optoelectronic device according to claim 1 , wherein said one or more second materials have refractive indices that fall in an interval having a width of 0.4; and

said first external dielectric region has a refractive index with a real part that falls within said interval.

13. A photon-detection system comprising:

an optoelectronic device that includes:

a first array of Geiger-mode avalanche photodiodes, said first array being formed in a die; and

a packaging structure that includes an internal dielectric structure directly on the die and overlying said photodiodes; and a first external dielectric region directly on the internal dielectric structure;

a light source optically coupled to the first array; and

a processing unit electrically coupled to the first array, wherein:

said first external dielectric region is formed by a first material that absorbs radiation having a wavelength that falls in a stop-band with a first wavelength range and transmits radiation having a wavelength that falls in a pass-band with a second wavelength range that is higher than the first wavelength range, at least part of said pass-band including infrared wavelengths;

said internal dielectric structure is formed by one or more second materials that substantially transmit radiation having a wavelength that falls in said stop-band and in said pass-band.

14. The photon-detection system according to claim 13 , wherein said processing unit comprises a microcontroller unit, or else a discriminator and a counter electrically coupled together.

15. The photon-detection system according to claim 13 , wherein said die comprises a semiconductor body having a front surface and forming a cathode region of a first type of conductivity; and wherein each photodiode comprises:

a respective anode region of a second type of conductivity, which extends within the cathode region; and

a lateral insulation region extending through the body starting from the front surface and surrounding the respective anode region and a corresponding part of the cathode region, said lateral insulation region including a barrier region and an insulating region, which surrounds the barrier region, said barrier region being configured to absorb or reflect radiation.

16. The photon-detection system according to claim 13 , wherein the optoelectronic device includes:

a second array of Geiger-mode avalanche photodiodes; and

a second external dielectric region overlying said second array and made of a third material having a different pass-band than the first material.

17. An optoelectronic device, comprising:

a first array of Geiger-mode avalanche photodiodes configured to detect incoming photons and emit secondary photons that have a wavelength in a first wavelength range between 400 nm and 600 nm;

a packaging structure, which includes:

a first external dielectric region formed by a first material that absorbs the secondary photons in the first wavelength range and transmits radiation having a wavelength that falls in a pass-band with a second wavelength range that is higher than the first wavelength range, at least part of said pass-band including infrared wavelengths; and

an internal dielectric structure positioned between the photodiodes and the first external dielectric region and formed by one or more second materials that substantially transmit radiation having a wavelength that falls in either of said first and second wavelength ranges.

18. The optoelectronic device according to claim 17 , comprising a semiconductor body having a front surface and forming a cathode region of a first type of conductivity; and wherein each photodiode comprises:

a respective anode region of a second type of conductivity, which extends within the cathode region; and

a lateral insulation region extending through the body starting from the front surface and surrounding the respective anode region and a corresponding part of the cathode region, said lateral insulation region including a barrier region and an insulating region, which surrounds the barrier region, said barrier region being configured to absorb or reflect radiation.

19. The optoelectronic device according to claim 18 , comprising a passivation region, which extends over the front surface, in contact with the semiconductor body;

and wherein said internal dielectric structure extends in contact with said passivation region and said passivation region, first external dielectric region, and internal dielectric structure each have a refractive index that falls in an interval having a width of 0.4.

20. The optoelectronic device according to claim 17 , further comprising:

a second array of Geiger-mode avalanche photodiodes; and

a second external dielectric region overlying said second array and made of a third material having a different pass-band than the first material.