Wide spectrum optical sensor
An optical sensor including a semiconductor substrate; a first light absorption region formed in the semiconductor substrate, the first light absorption region configured to absorb photons at a first wavelength range and to generate photo-carriers from the absorbed photons; a second light absorption region formed on the first light absorption region, the second light absorption region configured to absorb photons at a second wavelength range and to generate photo-carriers from the absorbed photons; and a sensor control signal coupled to the second light absorption region, the sensor control signal configured to provide at least a first control level and a second control level.
1. An optical sensor comprising:
a semiconductor substrate;
a first gate formed on the semiconductor substrate;
a die supported by the semiconductor substrate;
a first light absorption region formed in the die, wherein the first light absorption region is configured to:
absorb first photons at a first wavelength range; and
generate first photo-carriers from the absorbed first photons;
a bonding layer between the semiconductor substrate and the die, wherein a part of the bonding layer is between the first gate and the die;
a second light absorption region formed in the semiconductor substrate, wherein the second light absorption region is configured to:
absorb second photons at a second wavelength range; and
generate second photo-carriers from the absorbed second photons; and
a first carrier-collection region formed in the semiconductor substrate, wherein the first carrier-collection region is configured to collect a portion of the first photo-carriers and has a polarity; and
a second carrier-collection region formed in the semiconductor substrate, wherein the second carrier-collection region is configured to collect a portion of the second photo-carriers and has a polarity opposite to the polarity of the first carrier-collection region.
2. The optical sensor of claim 1 , wherein the portion of the first photo-carriers collected by the first carrier-collection region are provided by the first light absorption region, the optical sensor further comprising:
a first readout region coupled to a first readout circuitry and has a polarity, the first readout region configured to provide the portion of the first photo-carriers collected by the first carrier-collection region to the first readout circuitry;
and a second readout region coupled to a second readout circuitry, wherein the second readout region has a polarity opposite to the polarity of the first readout region.
3. The optical sensor of claim 2 , further comprising:
a first control signal source coupled to the first gate, wherein a first control signal from the first control signal source controls carrier transport between the first carrier-collection region and the first readout region.
4. The optical sensor of claim 3 , further comprising:
a second gate formed on the semiconductor substrate, wherein:
the second gate is coupled to a second control signal source; and
a second control signal from the second control signal source controls carrier transport between the second carrier-collection region and the second readout region.
5. The optical sensor of claim 2 , wherein the portion of the second photo-carriers are distinct from the portion of the first photo-carriers.
6. The optical sensor of claim 2 , further comprising:
a second gate formed on the semiconductor substrate, wherein:
the second gate is coupled to a second control signal source; and
a second control signal from the second control signal source controls carrier transport between the second carrier-collection region and the second readout region.
7. The optical sensor of claim 2 , wherein the portion of the second photo-carriers collected by the second carrier-collection region are provided by the second light absorption region,
and the second readout region configured to provide the portion of the second photo-carriers collected by the second carrier-collection region to the second readout circuitry.
8. The optical sensor of claim 2 , wherein the first wavelength range is distinct from the second wavelength range.
9. The optical sensor of claim 1 , wherein the first carrier-collection region is between the second carrier-collection region and the first light absorption region.
10. An optical sensor comprising:
a semiconductor substrate;
a first gate formed on the semiconductor substrate;
a die supported by the semiconductor substrate;
a first light absorption region formed in the die, wherein the first light absorption region is configured to:
absorb first photons at a first wavelength range; and
generate first photo-carriers from the absorbed first photons;
a bonding layer between the semiconductor substrate and the die, wherein a part of the bonding layer is between the first gate and the die;
a second light absorption region formed in the semiconductor substrate, wherein the second light absorption region is configured to:
absorb second photons at a second wavelength range; and
generate second photo-carriers from the absorbed second photons;
a first readout region coupled to a first readout circuitry, wherein the first readout region has a polarity; and
a second readout region coupled to a second readout circuitry, wherein the second readout region has a polarity opposite to the polarity of the first readout region.
11. The optical sensor of claim 10 , further comprising:
a second gate formed on the semiconductor substrate, wherein a part of the bonding layer is between the second gate and the die.
12. The optical sensor of claim 10 , wherein the first wavelength range is distinct from the second wavelength range.
13. The optical sensor of claim 10 , wherein the second light absorption region and the first light absorption region overlap along a direction of an optical signal.
14. An optical sensor comprising:
a semiconductor substrate;
a first gate formed on the semiconductor substrate;
a die supported by the semiconductor substrate;
a first light absorption region formed in the die, wherein the first light absorption region is configured to:
absorb first photons at a first wavelength range; and
generate first photo-carriers from the absorbed first photons; and
a bonding layer between the semiconductor substrate and the die, wherein a part of the bonding layer is between the first gate and the die;
a second light absorption region formed in the semiconductor substrate, wherein the second light absorption region is configured to:
absorb second photons at a second wavelength range; and
generate second photo-carriers from the absorbed second photons;
a first carrier-collection region formed in the semiconductor substrate; and
a second carrier-collection region formed in the semiconductor substrate, wherein the first carrier-collection region is between second carrier-collection region and the first light absorption region.
15. The optical sensor of claim 14 , wherein a surface of the first light absorption region is flush with a surface of the die.
16. The optical sensor of claim 14 , wherein the first light absorption region comprises a p-doped region, an n-doped region, and an intrinsic region formed between the p-doped region and the n-doped region.
17. The optical sensor of claim 14 , wherein the first light absorption region comprises an intrinsic region comprising germanium.
18. The optical sensor of claim 14 , wherein the optical sensor further comprises:
a first readout region coupled to a first readout circuitry, the first readout region configured to provide a portion of the first photo-carriers collected by the first carrier-collection region to the first readout circuitry.
19. The optical sensor of claim 18 , further comprising:
a second readout region coupled to a second readout circuitry, the second readout region configured to provide the portion of the second photo-carriers collected by the second carrier-collection region to the second readout circuitry.