CN219286422U

CN219286422U - Silicon-based waveguide photoelectric detector

Info

Publication number: CN219286422U
Application number: CN202223393385.1U
Authority: CN
Inventors: 郑志明; 林智聪
Original assignee: Jiangsu Liange Technology Co ltd
Current assignee: Jiangsu Liange Technology Co ltd
Priority date: 2022-12-19
Filing date: 2022-12-19
Publication date: 2023-06-30
Anticipated expiration: 2032-12-19

Abstract

The utility model discloses a silicon-based waveguide photoelectric detector, which comprises a silicon substrate, a silicon dioxide layer, a silicon optical waveguide, a light absorption layer, a DBR light reflector, an electrode and a passivation layer, wherein the silicon substrate is arranged on the silicon dioxide layer; the silicon substrate is provided with a silicon dioxide layer, and the silicon optical waveguide is prepared on the silicon dioxide layer of the silicon substrate along the head-to-tail direction; the light absorption layer grows on the silicon optical waveguide at a position close to the middle of the tail end, and the DBR light reflector is prepared on the light absorption layer at a position close to the middle of the tail end; the passivation layer is prepared on the silicon optical waveguide and the light absorption layer, forms cladding on the silicon optical waveguide and the light absorption layer and is contacted with the silicon dioxide layer on the silicon substrate; the two electrodes are respectively arranged on two sides of the light absorption layer along the head-tail direction and are contacted with the silicon optical waveguide. The utility model realizes high-sensitivity light detection under the condition that the absorption coefficient of the light absorbing material is relatively low.

Description

Silicon-based waveguide photoelectric detector

Technical Field

The utility model relates to the technical field of photoelectric communication and optical sensing, in particular to a silicon-based waveguide photoelectric detector.

Background

The silicon-based photoelectron technology integrates the microelectronic technology and the photoelectron technology, and has wide application prospect in the fields of optical communication, optical interconnection, optical sensing and the like. The silicon-based photoelectric detector converts optical signals into electric signals and is one of key devices; particularly for a certain working wavelength, the absorption coefficient of the light absorption layer of the detector is possibly lower, and even if a waveguide structure is adopted, the absorption length can be obviously increased, the responsivity is improved, but part of light is not absorbed, and the light can be dissipated from the tail end of the photoelectric detector, so that the device can not meet the actual application requirements.

Specifically, incident light enters the silicon optical waveguide and is transmitted to the light absorption layer, is coupled into the absorption layer through an evanescent field, is absorbed by the light absorption layer, generates photo-generated carriers (holes and electrons), and the holes and the electrons are separated and respectively transported to the positive electrode and the negative electrode under the action of an electric field to output an electric signal. However, if the absorption is low and the absorption response area of the detector is not long enough, a portion of the light is not absorbed and exits the end of the detector and is wasted. Therefore, the above problems need to be solved.

Disclosure of Invention

The technical problem to be solved by the utility model is to provide the silicon-based waveguide photoelectric detector, wherein the DBR light reflector is prepared on the light absorption layer near the tail end, so that unabsorbed light can be reflected back and continuously transmitted in the light absorption layer and absorbed, and therefore, under the condition that the absorption coefficient of a light absorption material is relatively low, the light absorption is improved, the responsivity is further improved, and the high-sensitivity light detection is realized.

In order to solve the technical problems, the utility model adopts the following technical scheme: the utility model relates to a silicon-based waveguide photoelectric detector, which is characterized in that: the device comprises a silicon substrate, a silicon dioxide layer, a silicon optical waveguide, a light absorption layer, a DBR light reflector, an electrode and a passivation layer; the silicon substrate is provided with a silicon dioxide layer, and the silicon optical waveguide is prepared on the silicon dioxide layer of the silicon substrate along the head-to-tail direction; the light absorption layer grows on the silicon optical waveguide at a position close to the middle of the tail end, and the DBR light reflector is prepared on the light absorption layer at a position close to the middle of the tail end; the passivation layer is prepared on the silicon optical waveguide and the light absorption layer, forms cladding on the silicon optical waveguide and the light absorption layer and is contacted with the silicon dioxide layer on the silicon substrate; the two electrodes are respectively arranged on two sides of the light absorption layer along the head-tail direction and are contacted with the silicon optical waveguide.

Preferably, the thickness of the silicon dioxide layer is 2 μm and the thickness of the surface silicon layer is 220nm.

Preferably, the silicon optical waveguide below the region where the light absorption layer is located is thinner than or has the same thickness as the other regions of the silicon optical waveguide.

Preferably, the preparation positions of the two electrodes are as follows: one electrode is prepared on and in contact with the light absorbing layer in the head-to-tail direction, and the other electrode is prepared on and in contact with the silicon optical waveguide in the head-to-tail direction.

The utility model has the beneficial effects that:

(1) According to the utility model, the DBR light reflector is prepared on the light absorption layer near the tail end, so that light which is not absorbed can be reflected back and is continuously transmitted in the light absorption layer and absorbed, thus under the condition that the absorption coefficient of the light absorption material is relatively low, the light absorption is improved, the responsivity is further improved, and high-sensitivity light detection is realized;

(2) The utility model is suitable for realizing high-speed high-response detection under the condition of low absorption coefficient, and solves the problem that the prior art is difficult to realize high-speed and high-response detection under the condition of low absorption coefficient.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a silicon-based waveguide photodetector of the present utility model.

Fig. 2 is a top view of fig. 1.

Wherein, 1-silicon substrate; a 2-silicon dioxide layer; 3-silicon optical waveguide; 4-a light absorbing layer; a 5-DBR light mirror; 6-electrode.

Description of the embodiments

The technical scheme of the present utility model will be clearly and completely described in the following detailed description.

The utility model relates to a silicon-based waveguide photoelectric detector, which comprises a silicon substrate 1, a silicon dioxide layer 2, a silicon optical waveguide 3, a light absorption layer 4, a DBR light reflector 5, an electrode 6 and a passivation layer; the specific structure is shown in fig. 1 and 2, a silicon dioxide layer 2 is arranged on a silicon substrate 1, the thickness of the silicon dioxide layer 2 is 2 mu m, and the thickness of the surface silicon layer is 220nm.

As shown in fig. 1 and 2, a silicon optical waveguide 3 is prepared on a silicon dioxide layer 2 of a silicon substrate 1 along the head-tail direction, and a light absorbing layer 4 is grown on the silicon optical waveguide 3 near the middle position of the tail end, wherein the light absorbing layer 4 is germanium, germanium-silicon, germanium quantum dots, germanium-tin alloy, germanium-lead alloy, germanium-tin-lead alloy or quantum well and quantum dot materials containing the same. Wherein the silicon optical waveguide 3 below the region where the light absorbing layer 4 is located is thinner than or the same as the thickness of the other regions of the silicon optical waveguide 3.

As shown in fig. 1 and 2, the DBR optical mirror 5 is disposed on the light absorbing layer 4 near the middle of the end, and the DBR optical mirror 5 may be made of a medium such as silicon oxide, silicon nitride, or aluminum oxide, or may be made of an organic material such as benzocyclobutene, parylene, polyimide, or polymethyl methacrylate.

As shown in fig. 1 and 2, a passivation layer is formed on the silicon optical waveguide 3 and the light absorption layer 4, and covers the silicon optical waveguide 3 and the light absorption layer 4 and contacts the silicon oxide layer 2 on the silicon substrate 1.

As shown in fig. 1 and 2, two electrodes 6 are respectively prepared on both sides of the light absorbing layer 4 in the head-to-tail direction and are in contact with the silicon optical waveguide 3. The preparation positions of the two electrodes 6 of the utility model can also be: one electrode 6 is provided on the light absorbing layer 4 in the head-to-tail direction and is in contact with the light absorbing layer 4, and the other electrode 6 is provided on the silicon optical waveguide 3 in the head-to-tail direction and is in contact with the silicon optical waveguide 3.

The working principle of the utility model is as follows: incident light enters the silicon optical waveguide 3 and is transmitted to the light absorption layer 4, enters the absorption layer through evanescent field coupling, is absorbed by the light absorption layer 4, generates photogenerated carriers (holes and electrons), and under the action of an electric field, the holes and the electrons are separated and respectively transmitted to the positive electrode and the negative electrode 6 to output an electric signal; in the process, the DBR light reflector 5 is prepared on the light absorption layer 4 near the tail end, so that light which is not absorbed can be reflected back and is continuously transmitted in the light absorption layer 4 and absorbed, and therefore, under the condition that the absorption coefficient of the light absorption material is low, the light absorption is improved, the responsivity is further improved, and high-sensitivity light detection is realized.

The utility model has the beneficial effects that:

(1) The DBR light reflector 5 is prepared on the light absorption layer 4 near the tail end, so that light which is not absorbed can be reflected back and is continuously transmitted in the light absorption layer 4 and absorbed, and therefore, under the condition that the absorption coefficient of a light absorption material is relatively low, the light absorption is improved, the responsivity is improved, and high-sensitivity light detection is realized;

The above embodiments are merely illustrative of the preferred embodiments of the present utility model, and the present utility model is not limited to the above embodiments, and various modifications and improvements made by those skilled in the art to the technical solutions of the present utility model without departing from the design concept of the present utility model should fall within the protection scope of the present utility model, and the claimed technical content of the present utility model is fully described in the claims.

Claims

1. A silicon-based waveguide photodetector, characterized by: the device comprises a silicon substrate, a silicon dioxide layer, a silicon optical waveguide, a light absorption layer, a DBR light reflector, an electrode and a passivation layer; the silicon substrate is provided with a silicon dioxide layer, and the silicon optical waveguide is prepared on the silicon dioxide layer of the silicon substrate along the head-to-tail direction; the light absorption layer grows on the silicon optical waveguide at a position close to the middle of the tail end, and the DBR light reflector is prepared on the light absorption layer at a position close to the middle of the tail end; the passivation layer is prepared on the silicon optical waveguide and the light absorption layer, forms cladding on the silicon optical waveguide and the light absorption layer and is contacted with the silicon dioxide layer on the silicon substrate; the two electrodes are respectively arranged on two sides of the light absorption layer along the head-tail direction and are contacted with the silicon optical waveguide.

2. A silicon-based waveguide photodetector according to claim 1, wherein: the thickness of the silicon dioxide layer was 2 μm, and the thickness of the surface silicon layer was 220nm.

3. A silicon-based waveguide photodetector according to claim 1, wherein: the thickness of the silicon optical waveguide below the region where the light absorption layer is located is thinner or the same as that of other regions of the silicon optical waveguide.

4. A silicon-based waveguide photodetector according to claim 1, wherein: the preparation positions of the two electrodes are as follows: one electrode is prepared on and in contact with the light absorbing layer in the head-to-tail direction, and the other electrode is prepared on and in contact with the silicon optical waveguide in the head-to-tail direction.