Photodiode and manufacturing method thereof

Abstract

This invention provides a photodiode and its manufacturing method. The photodiode includes a substrate, a first conductivity epitaxial layer, an intrinsic epitaxial layer, a second conductivity in-situ doped epitaxial layer, and a first laser-sintered sidewall. The first conductivity epitaxial layer is disposed on the substrate, the intrinsic epitaxial layer is disposed on the first conductivity epitaxial layer, and the second conductivity in-situ doped epitaxial layer is disposed on the intrinsic epitaxial layer. The first laser-sintered sidewall is disposed on the outer periphery of one of the second conductivity in-situ doped epitaxial layers to define an active region and substantially block external light from entering the second conductivity in-situ doped epitaxial layer through the device sidewall. The sidewalls of the substrate, the first conductivity epitaxial layer, the intrinsic epitaxial layer, and the second conductivity in-situ doped epitaxial layer collectively define the device sidewall, and the first laser-sintered sidewall is disposed inside the device sidewall.

Claims

1. A photodiode, comprising: a substrate; a first conductivity epitaxial layer disposed on the substrate; an intrinsic epitaxial layer disposed on the first conductivity epitaxial layer; a second conductivity in-situ doped epitaxial layer disposed on the intrinsic epitaxial layer; and a first laser-sintered sidewall disposed on the outer periphery of one of the second conductivity in-situ doped epitaxial layers to define an active region and substantially block external light from entering the second conductivity in-situ doped epitaxial layer through a device sidewall, wherein the sidewalls of the substrate, the first conductivity epitaxial layer, the intrinsic epitaxial layer, and the second conductivity in-situ doped epitaxial layer together define the device sidewall, and the first laser-sintered sidewall is disposed inside the device sidewall.

2. The photodiode as described in claim 1, wherein the first laser sintered sidewall is further disposed in the intrinsic epitaxial layer.

3. The photodiode as claimed in claim 1, wherein the first laser sintered sidewall has a length of not less than 1 micrometer (µm) to substantially block external light from entering the second conductive in-situ doped epitaxial layer through the sidewall of the device.

4. The photodiode as claimed in claim 1, wherein the sidewall of the element is a second laser-sintered sidewall.

5. The photodiode as described in claim 1, wherein the second conductivity type in-situ doped epitaxial layer is a P-type in-situ doped indium phosphide (InP) epitaxial layer, the dopant being one of zinc (Zn), magnesium (Mg), or beryllium (Be), and the doping concentration being 10¹⁷~19 cm⁻³.

6. The photodiode as described in claim 1 further comprises a metal ring disposed on the upper surface of the second conductivity type in-situ doped epitaxial layer at the inner upper edge of the first laser sintered sidewall.

7. The photodiode as claimed in claim 6, wherein one of the materials of the metal ring is selected from one or a combination thereof of the group consisting of chromium (Cr), palladium (Pd), aluminum (Al), titanium (Ti), nickel (Ni), and gold (Au).

8. The photodiode as claimed in claim 1 further comprises an N-type metal disposed on one side of the substrate opposite to the first conductive epitaxial layer, wherein one of the materials of the N-type metal is selected from one or a combination of germanium (Ge) and gold (Au).

9. A method for manufacturing a photodiode, comprising: providing a first conductivity epitaxial layer disposed on a substrate; providing an intrinsic epitaxial layer disposed on the first conductivity epitaxial layer; providing a second conductivity in-situ doped epitaxial layer disposed on the intrinsic epitaxial layer; providing a first laser sintered sidewall disposed on an outer periphery of the second conductivity in-situ doped epitaxial layer to define an active region; and providing a device sidewall disposed on each sidewall of the substrate, the first conductivity epitaxial layer, the intrinsic epitaxial layer, and the second conductivity in-situ doped epitaxial layer, wherein the first laser sintered sidewall is disposed inside the device sidewall to substantially block external light from entering the second conductivity in-situ doped epitaxial layer through the device sidewall.

10. The method of manufacturing a photodiode as claimed in claim 9, wherein providing a first laser sintered sidewall is to provide a first laser to form the first laser sintered sidewall, which is disposed on the outer periphery of one of the second conductivity type in-situ doped epitaxial layers and in the intrinsic epitaxial layer.

11. The method of manufacturing a photodiode as claimed in claim 9, wherein the provision of a first laser sintered sidewall is provided with a length of not less than 1 micrometer (µm) to substantially block external light from entering the second conductivity type in-situ doped epitaxial layer through the device sidewall.

12. The method of manufacturing a photodiode as claimed in claim 9, wherein providing an element sidewall is provided by providing a second laser to form a second laser sintered sidewall, disposed on each sidewall of the substrate, the first conductivity epitaxial layer, the intrinsic epitaxial layer and the second conductivity in-situ doped epitaxial layer.

13. The method of manufacturing a photodiode as claimed in claim 9, wherein the provision of a second conductivity type in-situ doped epitaxial layer is provided as a P-type in-situ doped indium phosphide (InP) epitaxial layer.

14. The method for manufacturing a photodiode as described in claim 13, wherein the indium phosphide (InP) epitaxial layer provided by providing a P-type in-situ doped indium phosphide (InP) epitaxial layer is simultaneously doped with one of zinc (Zn), magnesium (Mg), or beryllium (Be) during the indium phosphide (InP) epitaxial process by metal-organic chemical vapor deposition (MOCVD), and the doping concentration is 10¹⁷ to 19 cm⁻³.

15. The method for manufacturing a photodiode as claimed in claim 9 further includes a step of providing a metal ring followed by a step of providing a first laser sintered sidewall, such that the metal ring is disposed around the upper surface of the second conductivity type in-situ doped epitaxial layer at the inner upper edge of the first laser sintered sidewall.

16. The method of manufacturing a photodiode as claimed in claim 15, wherein the step of providing a metal ring is to provide a material selected from one or a combination thereof of the group consisting of chromium (Cr), palladium (Pd), aluminum (Al), titanium (Ti), nickel (Ni), and gold (Au).

17. The method for manufacturing a photodiode as claimed in claim 9 further includes a step of providing an N-type metal disposed on one side of the substrate opposite to the first conductive epitaxial layer, wherein one of the materials of the N-type metal is selected from one or a combination of germanium (Ge) and gold (Au).

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