Light-sensing apparatus and light-sensing method thereof
A photo-detecting apparatus is provided. The photo-detecting apparatus includes: a substrate made by a first material or a first material-composite; an absorption layer made by a second material or a second material-composite, the absorption layer being supported by the substrate and the absorption layer including: a first surface; a second surface arranged between the first surface and the substrate; and a channel region having a dopant profile with a peak dopant concentration equal to or more than 1×10 15 cm −3 , wherein a distance between the first surface and a location of the channel region having the peak dopant concentration is less than a distance between the second surface and the location of the channel region having the peak dopant concentration, and wherein the distance between the first surface and the location of the channel region having the peak dopant concentration is not less than 30 nm.
1. A photo-detecting apparatus, comprising:
a substrate made by a first material or a first material-composite;
an absorption layer made by a second material or a second material-composite, the absorption layer being supported by the substrate and the absorption layer comprising:
a first surface;
a second surface arranged between the first surface and the substrate; and
a channel region having a dopant profile with a peak dopant concentration equal to or more than 1×10 15 cm −3 , wherein a distance between the first surface and a location of the channel region having the peak dopant concentration is less than a distance between the second surface and the location of the channel region having the peak dopant concentration, and wherein the distance between the first surface and the location of the channel region having the peak dopant concentration is not less than 30 nm.
2. The photo-detecting apparatus of claim 1 further comprising:
two switches, each switch comprising a first portion of the absorption layer and a control contact layer that is electrically coupled to and arranged over a respective first portion of absorption layer.
3. The photo-detecting apparatus of claim 2 , wherein the channel region is arranged between the two switches and the second surface along a direction substantially perpendicular to the first surface of the absorption layer.
4. The photo-detecting apparatus of claim 2 , wherein each switch comprises a second portion of the absorption layer and a readout contact layer electrically coupled to and arranged over a respective second portion of absorption layer, wherein each second portion of the absorption layer of the two switches further comprises a first doped region of a first conductivity type, and wherein each of the first doped regions is electrically coupled to a respective readout contact layer.
5. The photo-detecting apparatus of claim 4 , wherein a conductivity type of the channel region is a same conductivity type as the first conductivity type of the first doped regions.
6. The photo-detecting apparatus of claim 4 , wherein the absorption layer further comprises a hinder region that is arranged between two first doped regions and arranged between the channel region and the first surface.
7. The photo-detecting apparatus of claim 6 , wherein the hinder region has a dopant profile having a peak dopant concentration different from the peak dopant concentration of the channel region.
8. The photo-detecting apparatus of claim 6 , wherein a conductivity type of the hinder region is the same as the conductivity type of the channel region, and the peak dopant concentration of the hinder region is lower than the peak dopant concentration of the channel region.
9. The photo-detecting apparatus of claim 6 , wherein a conductivity type of the hinder region the hinder region is different from the conductivity type of the channel region, and the peak dopant concentration of the hinder region is higher than the peak dopant concentration of the channel region.
10. The photo-detecting apparatus of claim 9 , wherein the peak dopant concentration of the hinder region is between 1×10 18 cm −3 and 5×10 20 cm −3 .
11. The photo-detecting apparatus of claim 4 , wherein the channel region is overlapped with the first doped regions.
12. The photo-detecting apparatus of claim 4 , wherein each second portion of the absorption layer of the two switches further comprises a second doped region arranged between a respective control contact layer and the second surface of the absorption layer, wherein each of the second doped regions is of a second conductivity type different from the first conductivity type.
13. The photo-detecting apparatus of claim 4 , further comprising two counter-doped regions, wherein each of the two counter-doped regions overlaps with at least a portion of the first doped regions, and the two counter-doped regions are of a conductivity type different from the first conductivity type of the first doped regions.
14. The photo-detecting apparatus of claim 4 , further comprising a first buffer region and a second buffer region between two first doped regions.
15. The photo-detecting apparatus of claim 14 , wherein each of the first buffer region and the second buffer region includes a depth less than a depth of each of the first doped regions.
16. The photo-detecting apparatus of claim 2 , wherein a width of the channel region is greater than a distance between control contact layers.
17. The photo-detecting apparatus of claim 1 , wherein a width of the channel region is between 10 nm and 500 nm.
18. The photo-detecting apparatus of claim 1 , wherein the distance between the first surface of the absorption layer and the location of the peak dopant concentration of the channel region is between 50 nm and 650 nm.
19. The photo-detecting apparatus of claim 1 , wherein the peak dopant concentration of the channel region is between 1×10 15 cm −3 and 5×10 17 cm −3 .
20. An imaging system comprising:
one or more cameras; and
a photo-detecting apparatus comprising a pixel-array for time-of-flight information, each pixel of the pixel-array comprising:
a substrate made by a first material or a first material-composite;
an absorption layer made by a second material or a second material-composite, the absorption layer being supported by the substrate and the absorption layer comprising:
a first surface;
a second surface arranged between the first surface and the substrate; and
a channel region having a dopant profile with a peak dopant concentration equal to or more than 1×10 15 cm −3 , wherein a distance between the first surface and a location of the channel region having the peak dopant concentration is less than a distance between the second surface and the location of the channel region having the peak dopant concentration, and wherein the distance between the first surface and the location of the channel region having the peak dopant concentration is not less than 30 nm.