High-speed light sensing apparatus
An apparatus including a semiconductor substrate; an absorption layer coupled to the semiconductor substrate, the absorption layer including a photodiode region configured to absorb photons and to generate photo-carriers from the absorbed photons; one or more first switches controlled by a first control signal, the one or more first switches configured to collect at least a portion of the photo-carriers based on the first control signal; and one or more second switches controlled by a second control signal, the one or more second switches configured to collect at least a portion of the photo-carriers based on the second control signal, where the second control signal is different from the first control signal.
1. An optical apparatus, comprising:
a semiconductor substrate having a first material composition;
a light absorption material supported by the semiconductor substrate and having a second material composition different from the first material composition, wherein the light absorption material is configured to:
absorb incident light within a first wavelength band; and
generate photo-carriers in response to absorbing the incident light;
a first switch electrically coupled to the light absorption material and comprising:
a first terminal configured to receive a first control signal; and
a second terminal configured to collect at least some of the photo-carriers; and
a first read-out circuit electrically coupled to the second terminal of the first switch and configured to read out the photo-carriers collected by the second terminal of the first switch.
2. The optical apparatus of claim 1 , wherein the first material composition comprises silicon.
3. The optical apparatus of claim 1 , wherein the second material composition comprises germanium.
4. The optical apparatus of claim 1 , wherein the first wavelength band comprises near-infrared (NIR) light.
5. The optical apparatus of claim 1 , further comprising a metal layer arranged over the light absorption material.
6. The optical apparatus of claim 1 , wherein the first terminal comprises a first p-doped region and the second terminal comprises a first n-doped region.
7. The optical apparatus of claim 6 , wherein the first p-doped region is entirely or partially formed within an n-well region.
8. The optical apparatus of claim 1 , wherein the light absorption material is embedded in the semiconductor substrate.
9. A system, comprising:
a light source for generating photons within a first wavelength band; and
an image sensor comprising a plurality of pixels supported by a semiconductor substrate having a first material composition, wherein each pixel of the plurality of pixels comprises:
a light absorption material supported by the semiconductor substrate and having a second material composition different from the first material composition, wherein the light absorption material is configured to:
absorb an incident light within the first wavelength band; and
generate photo-carriers in response to absorbing the incident light;
one or more first switches electrically coupled to a first read-out circuit and controlled by a first control signal, each first switch of the one or more first switches configured to collect at least a first portion of the photo-carriers based on the first control signal; and
one or more second switches electrically coupled to a second read-out circuit and controlled by a second control signal, each second switch of the one or more second switches configured to collect at least a second portion of the photo-carriers based on the second control signal,
wherein the first portion of the photo-carriers and the second portion of the photo-carriers are of a same type of carriers.
10. The system of claim 9 , wherein the second material composition comprises a germanium composition.
11. The system of claim 9 , further comprising a metal layer arranged over the light absorption material.
12. The system of claim 9 , wherein the light absorption material is embedded in the semiconductor substrate.