Photo-current amplification apparatus
A photo-current amplification apparatus is provided. The photo-current amplification apparatus includes a photo-detecting device including: a substrate; an absorption region comprising germanium, the absorption region supported by the substrate and configured to receive an optical signal and to generate a first electrical signal based on the optical signal; an emitter contact region of a conductivity type; and a collector contact region of the conductivity type, wherein at least one of the emitter contact region or the collector contact region is formed outside the absorption region, and wherein a second electrical signal collected by the collector contact region is greater than the first electrical signal generated by the absorption region.
1. A photo-current amplification apparatus, comprising:
a photo-detecting device, comprising:
a substrate comprising silicon;
an absorption region comprising germanium, the absorption region supported by the substrate, wherein the absorption region comprises a p-doped absorption region configured to receive an optical signal and to generate a first electrical signal based on the optical signal;
an emitter contact region formed in the absorption region;
a collector contact region outside of the absorption region, wherein the collector contact region is n-doped; and
a base region formed in the absorption region, wherein the base region is p-doped having a peak doping concentration higher than that of the p-doped absorption region,
wherein a second electrical signal collected by the collector contact region is greater than the first electrical signal generated by the absorption region.
2. The photo-current amplification apparatus of claim 1 , wherein the base region is formed in the absorption region, and wherein a doping concentration of a dopant of the base region is between 1×10 16 cm −3 to 1×10 19 cm −3 .
3. The photo-current amplification apparatus of claim 1 , wherein the photo-detecting device further comprises a first electrode electrically coupled to the emitter contact region, and wherein the photo-detecting device further comprises a second electrode electrically coupled to the collector contact region.
4. The photo-current amplification apparatus of claim 1 , further comprising a sustaining circuit electrically coupled to the photo-detecting device, wherein the sustaining circuit is configured to control a gain of the photo-detecting device.
5. The photo-current amplification apparatus of claim 4 , wherein the sustaining circuit includes a passive element including an inductor or a resistor.
6. The photo-current amplification apparatus of claim 4 , wherein the sustaining circuit includes an active element including a switch or a transistor.
7. The photo-current amplification apparatus of claim 4 , further including a bonding layer that bonds the sustaining circuit and the photo-detecting device.
8. The photo-current amplification apparatus of claim 1 , wherein the substrate further comprises a p-doped region formed between the collector contact region and the base region.
9. The photo-current amplification apparatus of claim 1 , wherein the substrate further comprises an intrinsic region formed between the collector contact region and the base region.
10. The photo-current amplification apparatus of claim 1 , wherein the base region at least partially surrounds the emitter contact region.
11. The photo-current amplification apparatus of claim 1 , wherein the collector contact region at least partially surrounds the base region.
12. The photo-current amplification apparatus of claim 1 , wherein the emitter contact region is n-doped.