US 2018/0019269 A1 · DUAL BAND PHOTODETECTOR AND A METHOD THEREOF

Abstract

Photodetectors and methods for dual band photo detection are disclosed. The photodetector includes a stack of semiconductor layers defining first and second unipolar photosensitive modules (UPMs) of respectively opposite doping polarities, and a contact layer including at least one of metal and semiconductor materials having doping polarity opposite to that of the second UPM. The first and second UPMs are adapted for sensing radiation of different respective first and second wavelengths ranges. The second UPM is located upon the first UPM thereby forming a first diode junction between the first and second UPMs. The contact layer is located on the second UPM thereby forming a second diode junction between the second UPM and the contact layer. The first and second diode junctions are configured to have respectively opposite conduction directions, enabling selective sensing of electrical signals associated with the first and second wavelengths ranges.

Claims22

Dependent claims

A photodetector for dual band photo detection, the photo detector comprising:

a stack of semiconductor layers defining a first unipolar photosensitive module (UPM) and a second UPM of respectively opposite doping polarities;
and
a contact layer comprising at least one of a metal material or a semiconductor material having doping polarity opposite to that of the second UPM;
wherein the first and second UPMs are respectively adapted for sensing radiation of different respective first and second wavelengths ranges;
wherein said second UPM is located upon said first UPM along a certain direction, thereby forming a first diode junction between the first and second UPMs;
wherein said contact layer is located on said second UPM, thereby forming a second diode junction between the second UPM and the contact layer;
and
wherein said first and second diode junctions have respectively opposite conduction directions, thereby enabling to selectively sense electrical signals associated with said first and second wavelengths ranges.

5 more elements

A method for fabrication of a photodetector for dual band photo detection, the method comprising:

(a) fabricating a first unipolar photosensitive module (UPM) of a first doping polarity, said fabrication of the first UPM comprising:
growing a buffer layer on a substrate;
growing a first photon absorbing layer on said buffer layer doped with a certain first doping polarity;
and
growing a first barrier layer doped in at least a first region thereof, which interfaces with the first photon absorbing layer, with the same first doping polarity;
(b) fabricating a second UPM of a second doping polarity opposite to said first doping polarity on top of said first UPM thereby forming a first diode junction between the first and second UPMs;
said fabrication of the second UPM comprising:
growing a second photon absorbing layer doped with the second doping polarity above said first barrier layer;
and
growing a second barrier layer with at least a region thereof interfacing the second photon absorbing layer, doped with the second doping polarity;
and
(c) fabricating a contact layer above said second barrier layer thereby forming a second diode junction between the second UPM and the contact layer.

9 more elements

Dependencies are inferred from the claim text.

Dual band photodetector and a method thereof

Life of this patent

Dual band photodetector and a method thereof

Life of this patent

Abstract

Claims22