阅读说明：本技术 半导体激光器的缺陷识别方法 (Defect identification method for semiconductor laser ) 是由 李德尧 温鹏雁 黄思溢 张立群 刘建平 张书明 杨辉 于 2020-06-10 设计创作，主要内容包括：本发明提供了一种半导体激光器的缺陷识别方法,其包括：获取半导体激光器在老化过程中的电容和频率的第一关系曲线图；根据所述第一关系曲线图获取所述半导体激光器的缺陷能级信息和/或缺陷分布信息。本发明还提供了另一种半导体激光器的缺陷识别方法,其包括：获取半导体激光器在老化过程中的表观载流子浓度和耗尽区宽度的第二关系曲线图；根据所述第二关系曲线图获取所述半导体激光器的缺陷分布信息。本发明采用半导体激光器的电学特性来进行半导体激光器的缺陷识别,无需采用具有永久损伤的切割方法切割半导体材料之后来进行缺陷识别,从而可以实现无损识别半导体激光器的缺陷,进而不会对半导体激光器造成永久性损伤。(The invention provides a defect identification method of a semiconductor laser, which comprises the following steps: acquiring a first relation curve graph of capacitance and frequency of the semiconductor laser in an aging process; and acquiring the defect energy level information and/or the defect distribution information of the semiconductor laser according to the first relation curve graph. The invention also provides another defect identification method of the semiconductor laser, which comprises the following steps: acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process; and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph. The invention adopts the electrical characteristics of the semiconductor laser to identify the defects of the semiconductor laser, and does not need to identify the defects after cutting the semiconductor material by a cutting method with permanent damage, thereby realizing the nondestructive identification of the defects of the semiconductor laser and further avoiding permanent damage to the semiconductor laser.)

1. A defect identification method of a semiconductor laser, comprising:

acquiring a first relation curve graph of capacitance and frequency of the semiconductor laser in an aging process;

and acquiring the defect energy level information and/or the defect distribution information of the semiconductor laser according to the first relation curve graph.

2. The defect identification method of claim 1, wherein obtaining the defect level information of the semiconductor laser according to the first relation graph comprises:

under the condition that zero bias is applied to the semiconductor laser in the aging process, capacitance values of the semiconductor laser at low frequency and high frequency are changed, and the defect energy level information comprises shallow energy level defects;

in the case where the semiconductor laser is negatively biased during burn-in, a capacitance value of the semiconductor laser at a low frequency changes, and the defect level information includes deep level defects.

3. The defect identification method according to claim 1 or 2, wherein acquiring the defect distribution information of the semiconductor laser according to the first relation graph comprises:

the active region of the semiconductor laser generates the shallow level defect under the condition that the semiconductor laser is applied with zero bias voltage in the aging process;

the deep level defects are generated by an N-type layer of the semiconductor laser when the semiconductor laser is negatively biased during burn-in.

4. The defect identification method according to claim 1 or 2, further comprising:

acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process;

and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph.

5. The defect identification method of claim 4, wherein obtaining the defect distribution information of the semiconductor laser according to the second relation graph comprises:

in a first aging stage of the semiconductor laser, shallow level defects are generated in an active layer of the semiconductor laser;

in a second aging stage of the semiconductor laser, deep level defects are generated in an N-type layer of the semiconductor laser;

wherein the first aging stage of the semiconductor laser refers to a stage of reducing from a normal original power of the semiconductor laser to half of the normal original power; the second aging stage of the semiconductor laser means a stage from half of the normal original power of the semiconductor laser to a stage where the semiconductor laser cannot emit laser light.

6. The defect identification method of claim 3, further comprising:

acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process;

and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph.

7. The defect identification method of claim 6, wherein obtaining the defect distribution information of the semiconductor laser according to the second relation graph comprises:

in a first aging stage of the semiconductor laser, shallow level defects are generated in an active layer of the semiconductor laser;

in a second aging stage of the semiconductor laser, deep level defects are generated in an N-type layer of the semiconductor laser;

wherein the first aging stage of the semiconductor laser refers to a stage of reducing from a normal original power of the semiconductor laser to half of the normal original power; the second aging stage of the semiconductor laser means a stage from half of the normal original power of the semiconductor laser to a stage where the semiconductor laser cannot emit laser light.

8. A defect identification method of a semiconductor laser, comprising:

acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process;

and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph.

9. The defect identification method of claim 6, wherein obtaining the defect distribution information of the semiconductor laser according to the second relation graph comprises:

in a first aging stage of the semiconductor laser, shallow level defects are generated in an active layer of the semiconductor laser;

in a second aging stage of the semiconductor laser, deep level defects are generated in an N-type layer of the semiconductor laser;

wherein the first aging stage of the semiconductor laser refers to a stage of reducing from a normal original power of the semiconductor laser to half of the normal original power; the second aging stage of the semiconductor laser means a stage from half of the normal original power of the semiconductor laser to a stage where the semiconductor laser cannot emit laser light.

10. The defect identification method of any one of claims 1 to 9, wherein the semiconductor laser comprises: an N-type layer, an active layer and a P-type layer sequentially stacked on the substrate;

the N-type layer sequentially comprises an N-type AlGaN limiting layer, an N-type GaN waveguide layer and an N-type InGaN waveguide layer which are stacked from the substrate to the active layer;

the active layer comprises a first GaN barrier layer, a first InGaN quantum well layer, a second GaN barrier layer, a second InGaN quantum well layer and a second GaN barrier layer which are stacked in sequence from the N-type layer to the P-type layer;

the P-type layer comprises a P-type InGaN waveguide layer, a P-type AlGaN limiting layer and a P-type GaN contact layer which are sequentially stacked on the second GaN barrier layer.

Technical Field

The invention belongs to the technical field of photoelectricity, and particularly relates to a defect identification method of a semiconductor laser, which can nondestructively identify the defects of the semiconductor laser.

Background

The semiconductor laser is used as an important semiconductor light-emitting device and has wide application prospect in the fields of laser display, laser illumination and the like. When a semiconductor laser is manufactured, a large number of defects are generated in the manufacturing process of growing semiconductor materials and the like.

The defect identification method in the traditional semiconductor laser can only identify the defects on the surface of the semiconductor material, and if the defects in the semiconductor material need to be identified, the defect identification can only be carried out after the semiconductor material is cut by a cutting method with permanent damage, but the permanent damage is usually caused to the semiconductor laser.

Disclosure of Invention

In order to solve the technical problems of the prior art, the present invention provides a defect identification method for a semiconductor laser, which can identify defects of the semiconductor laser without damage.

According to an aspect of the present invention, there is provided a defect identification method of a semiconductor laser, including: acquiring a first relation curve graph of capacitance and frequency of the semiconductor laser in an aging process; and acquiring the defect energy level information and/or the defect distribution information of the semiconductor laser according to the first relation curve graph.

In the defect identifying method according to an aspect of the present invention, acquiring defect level information of the semiconductor laser according to the first relation graph includes: under the condition that zero bias is applied to the semiconductor laser in the aging process, capacitance values of the semiconductor laser at low frequency and high frequency are changed, and the defect energy level information comprises shallow energy level defects; in the case where the semiconductor laser is negatively biased during burn-in, a capacitance value of the semiconductor laser at a low frequency changes, and the defect level information includes deep level defects.

In the defect identifying method provided by an aspect of the present invention, acquiring defect distribution information of the semiconductor laser according to the first relation graph includes: the active region of the semiconductor laser generates the shallow level defect under the condition that the semiconductor laser is applied with zero bias voltage in the aging process; the deep level defects are generated by an N-type layer of the semiconductor laser when the semiconductor laser is negatively biased during burn-in.

In the defect identifying method provided according to an aspect of the present invention, the defect identifying method further includes: acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process; and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph.

In the defect identifying method according to an aspect of the present invention, acquiring the defect distribution information of the semiconductor laser according to the second relation graph includes: in a first aging stage of the semiconductor laser, shallow level defects are generated in an active layer of the semiconductor laser; in a second aging stage of the semiconductor laser, deep level defects are generated in an N-type layer of the semiconductor laser; wherein the first aging stage of the semiconductor laser refers to a stage of reducing from a normal original power of the semiconductor laser to half of the normal original power; the second aging stage of the semiconductor laser means a stage from half of the normal original power of the semiconductor laser to a stage where the semiconductor laser cannot emit laser light.

According to another aspect of the present invention, there is also provided another defect identifying method of a semiconductor laser, including: acquiring a second relation curve graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process; and acquiring the defect distribution information of the semiconductor laser according to the second relation curve graph.

In a defect identifying method provided according to another aspect of the present invention, acquiring defect distribution information of the semiconductor laser according to the second relation graph includes: in a first aging stage of the semiconductor laser, shallow level defects are generated in an active layer of the semiconductor laser; in a second aging stage of the semiconductor laser, deep level defects are generated in an N-type layer of the semiconductor laser; wherein the first aging stage of the semiconductor laser refers to a stage of reducing from a normal original power of the semiconductor laser to half of the normal original power; the second aging stage of the semiconductor laser means a stage from half of the normal original power of the semiconductor laser to a stage where the semiconductor laser cannot emit laser light.

In the defect identifying method provided according to an aspect and/or another aspect of the present invention, the semiconductor laser includes: an N-type layer, an active layer and a P-type layer sequentially stacked on the substrate; the N-type layer sequentially comprises an N-type AlGaN limiting layer, an N-type GaN waveguide layer and an N-type InGaN waveguide layer which are stacked from the substrate to the active layer; the active layer comprises a first GaN barrier layer, a first InGaN quantum well layer, a second GaN barrier layer, a second InGaN quantum well layer and a second GaN barrier layer which are stacked in sequence from the N-type layer to the P-type layer; the P-type layer comprises a P-type InGaN waveguide layer, a P-type AlGaN limiting layer and a P-type GaN contact layer which are sequentially stacked on the second GaN barrier layer.

The invention has the beneficial effects that: the invention adopts the electrical characteristics of the semiconductor laser to identify the defects of the semiconductor laser, and does not need to identify the defects after cutting the semiconductor material by a cutting method with permanent damage, thereby realizing the nondestructive identification of the defects of the semiconductor laser and further avoiding permanent damage to the semiconductor laser.

Drawings

The above and other aspects, features and advantages of embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a voltage current graph of a semiconductor laser according to an embodiment of the present invention;

fig. 2A is a graph of capacitance versus frequency for a semiconductor laser at zero bias, according to an embodiment of the present invention;

fig. 2B is a graph of capacitance versus frequency for a semiconductor laser under negative bias, in accordance with an embodiment of the present invention;

fig. 3 is a flowchart of a defect identification method of a semiconductor laser according to a first embodiment of the present invention;

fig. 4 is a graph of apparent carrier concentration versus depletion region width for a semiconductor laser according to an embodiment of the present invention;

fig. 5 is a flowchart of a defect identifying method of a semiconductor laser according to a second embodiment of the present invention;

fig. 6 is a flowchart of a defect identifying method of a semiconductor laser according to a third embodiment of the present invention;

fig. 7 is a schematic structural diagram of an exemplary structure of a semiconductor laser according to the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and its practical application to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated.

Fig. 1 is a voltage-current graph of a semiconductor laser according to an embodiment of the present invention. Referring to fig. 1, three curves are shown, a first curve 11 corresponding to the semiconductor laser not being aged, a second curve 12 corresponding to the semiconductor laser being in a first aging stage, and a third curve 13 corresponding to the semiconductor laser being in a second aging stage.

Here, it should be noted that the first aging stage refers to a stage of decreasing from a normal original power of the semiconductor laser (i.e., the semiconductor laser is in an unaged stage) to half of the normal original power; and the second aging stage refers to a stage from half of the normal original power of the semiconductor laser to the stage where the semiconductor laser cannot emit laser light.

As can be seen from FIG. 1, the leakage current of the unaged semiconductor laser is 3E at a voltage of-6V^-9A. With the aging of the semiconductor laser, the reverse leakage current and the forward leakage current with the voltage below 2.8V of the semiconductor laser increase, and when the leakage current increases to 1E^-5At time a, the semiconductor laser cannot emit laser light. Here, the increase of the reverse leakage current of the semiconductor laser is due to the defect of the semiconductor laser generating an additional tunneling or composite current channel under the reverse bias; at a low forward bias voltage, the defects of the semiconductor laser act as generation centers to accelerate tunneling of carriers. As shown in fig. 1, the semiconductor laser generates defects after aging.

Fig. 2A is a graph of capacitance versus frequency for a semiconductor laser according to an embodiment of the present invention at zero bias.

In fig. 2A, three curves are also shown, a first curve 21A corresponding to the semiconductor laser not being aged, a second curve 22A corresponding to the semiconductor laser being in a first aging stage, and a third curve 23A corresponding to the semiconductor laser being in a second aging stage.

Here, it should be noted that, as shown in fig. 1, the first aging stage refers to a stage of decreasing from a normal original power of the semiconductor laser (i.e., the semiconductor laser is in an unaged stage) to half of the normal original power; and the second aging stage refers to a stage from half of the normal original power of the semiconductor laser to the stage where the semiconductor laser cannot emit laser light.

Referring to fig. 2A, in a first aging stage, referring to a first curve 21A and a second curve 22A, the capacitance value of the semiconductor laser at low frequency remains substantially unchanged, while the capacitance value at high frequency increases significantly. It is known that the defects added to the semiconductor laser in the first aging stage are mainly shallow level defects because the density of the shallow level defects in the semiconductor laser increases after aging, which results in an increase in the capacitance value of the semiconductor laser at high frequencies. Here, although the capacitance value of the semiconductor laser remains substantially unchanged at a low frequency, a shallow level defect also exists at a low frequency in the semiconductor laser in the first aging stage. Thus, it can be seen here that the defect level information of a semiconductor laser, when at zero bias and in a first stage of aging, at low or high frequencies, comprises mainly shallow level defects. In addition, at zero bias, the depletion region of the semiconductor laser is located near the active layer, so defects (i.e., shallow level defects) occur in the active layer.

Here, it should be noted that the low frequency and the high frequency are only relative concepts, and those skilled in the art can know the division range of the low frequency and the high frequency in the semiconductor laser.

With continued reference to fig. 2A, in the second aging stage, referring to the second curve 22A and the third curve 23A, the third curve 23A can be substantially shifted downward from the second curve 22A, which indicates that the change in the capacitance value of the semiconductor laser at this stage is mainly due to the increase in the leakage current. Further, the capacitance of the semiconductor laser does not change at the second aging stage at either low or high frequency, indicating that defects in the semiconductor laser, i.e., deep level defects and shallow level defects, are not increased.

Fig. 2B is a graph of capacitance versus frequency for a semiconductor laser under negative bias, in accordance with an embodiment of the present invention.

In fig. 2B, three curves are also shown, a first curve 21B corresponding to the semiconductor laser not being aged, a second curve 22B corresponding to the semiconductor laser being in a first aging stage, and a third curve 23B corresponding to the semiconductor laser being in a second aging stage.

Here, it should be noted that, as shown in fig. 1, the first aging stage refers to a stage of decreasing from a normal original power of the semiconductor laser (i.e., the semiconductor laser is in an unaged stage) to half of the normal original power; and the second aging stage refers to a stage from half of the normal original power of the semiconductor laser to the stage where the semiconductor laser cannot emit laser light.

Referring to fig. 2B, a graph of capacitance versus frequency for a semiconductor laser at-20V bias is shown; it should be understood that-20V is merely an example and not a limitation. In the first aging stage, referring to the first curve 21B and the second curve 22B, the capacitance value of the semiconductor laser at low frequency is significantly increased, which indicates that the depletion region of the semiconductor laser is expanded toward the N-type region, while the capacitance value at low frequency is significantly increased, which indicates that the deep level defects are increased and the deep level defects are distributed in the N-type region.

With continued reference to fig. 2B, in the second aging stage, referring to the second curve 22B and the third curve 23B, the third curve 23B may be substantially shifted downward from the second curve 22B, which indicates that the change in the capacitance value of the semiconductor laser at this stage is mainly due to the increase in the leakage current. Further, the capacitance of the semiconductor laser does not change at the second aging stage at either low or high frequency, indicating that defects in the semiconductor laser, i.e., deep level defects and shallow level defects, are not increased.

The inventor of the invention provides a defect identification method of a semiconductor laser device, which can identify the defects of the semiconductor laser device according to the scientific research findings, and the method can identify the defects of the semiconductor laser device without adopting cutting and other modes because the defects are identified by adopting the electrical characteristics of the semiconductor laser device, thereby realizing the nondestructive identification of the defects of the semiconductor laser device.

Fig. 3 is a flowchart of a defect identification method of a semiconductor laser according to a first embodiment of the present invention.

Referring to fig. 3, the defect identifying method of the semiconductor laser according to the first embodiment of the present invention includes steps S310 and S320.

Specifically, in step S310, a graph of the relationship between the capacitance and the frequency of the semiconductor laser during the aging process is obtained.

In particular, reference may be made to the graphs of capacitance versus frequency of the semiconductor lasers shown in fig. 2A and 2B described above during aging.

Further, in step S320, the defect level information of the semiconductor laser is acquired according to the relationship graph.

Hereinafter, how to acquire the defect level information of the semiconductor laser from the relationship graph is described with reference to fig. 2A and 2B together with reference to fig. 3.

Specifically, referring to fig. 2A, in a case where the semiconductor laser is applied with a zero bias and the semiconductor laser is in a first aging stage, the defect level information of the semiconductor laser is a shallow level defect. Of course, as described above, in this case, the capacitance value corresponding to the semiconductor laser changes at a low frequency and the capacitance value corresponding to the semiconductor laser changes at a high frequency with respect to the shallow level defect. In other words, the defect level information includes a shallow level defect regardless of whether the frequency of the semiconductor laser is a low frequency or a high frequency.

In addition, it should be noted that when the semiconductor laser is applied with a zero bias voltage, the corresponding depletion region is the active layer (or near the active layer), so that defects (i.e., shallow level defects) occur in the active layer.

Further, referring to fig. 2B, in a case where the semiconductor laser is applied with a negative bias (e.g., -20V bias) and the semiconductor laser is in the first aging stage, the defect level information of the semiconductor laser is a deep level defect. Of course, as described above, in this case, the capacitance value of the semiconductor laser varies at a low frequency with respect to the deep level defect. In other words, the defect level information further includes deep level defects when the frequency of the semiconductor laser is a low frequency.

Further, it is to be noted that, when the semiconductor laser is negatively biased, the corresponding depletion region is an N-type region (or near the N-type region), and thus a defect (i.e., a deep level defect) occurs in the N-type region.

From the above, the defect level information and the defect distribution information of the semiconductor laser can be obtained from the graph of the relationship between the capacitance and the frequency of the semiconductor laser under the zero bias and/or the negative bias. However, the inventors of the present invention have found that the defect distribution information of the semiconductor laser obtained in this way is relatively rough, and therefore, the inventors of the present invention have proposed a new method for obtaining the defect distribution information of the semiconductor laser. This will be described in detail below.

Fig. 4 is a graph of apparent carrier concentration versus depletion region width for a semiconductor laser according to an embodiment of the present invention.

In fig. 4, three curves are also shown, a first curve 41 corresponding to a non-aged semiconductor laser, a second curve 42 corresponding to a first aged stage of the semiconductor laser, and a third curve 43 corresponding to a second aged stage of the semiconductor laser.

Here, it should be noted that, as shown in fig. 1, the first aging stage refers to a stage of decreasing from a normal original power of the semiconductor laser (i.e., the semiconductor laser is in an unaged stage) to half of the normal original power; and the second aging stage refers to a stage from half of the normal original power of the semiconductor laser to the stage where the semiconductor laser cannot emit laser light.

Referring to fig. 4, the two peak positions (i.e., QW1 and QW2) at about 117nm and 131nm of the depletion region correspond to the two quantum wells of the semiconductor laser. FIG. 4 shows that: the limiting capability on the apparent carriers is stronger when the quantum well is close to the N-type quantum well before aging; and with the increase of aging time, the apparent carrier concentration of the P-type quantum well increases; then, as the semiconductor laser further ages, the apparent carrier concentrations of both quantum wells (i.e., the N-type quantum well and the P-type quantum well) decrease, and a peak of the apparent carrier concentration occurs in the region corresponding to the N-type layer (i.e., S1). The inventors of the present invention thus determined that: in the first aging stage of the semiconductor laser, shallow level defects are generated in the active region (namely the active layer or the vicinity of the active layer) of the semiconductor laser; as the semiconductor laser further ages, i.e., in the second aging stage of the semiconductor laser, deep level defects are generated in the N-type layer.

Based on this, the inventors of the present application have proposed a defect identification method for a semiconductor laser, which is capable of identifying defects of the semiconductor laser, and which can realize non-destructive identification of defects of the semiconductor laser without using a method such as dicing, since defect identification is performed using electrical characteristics of the semiconductor laser.

Fig. 5 is a flowchart of a defect identifying method of a semiconductor laser according to a second embodiment of the present invention.

Referring to fig. 5, a defect identifying method of a semiconductor laser according to a second embodiment of the present invention includes steps S510 and S520.

Specifically, in step S510, a graph of the relationship between the apparent carrier concentration and the depletion region width of the semiconductor laser during the aging process is obtained.

In particular, reference may be made to the graph of the relationship between the apparent carrier concentration and the depletion region width during aging of the semiconductor laser shown in fig. 4 described above.

Further, in step S520, defect distribution information is obtained according to the relation graph (shown in fig. 4).

How to acquire the defect distribution information of the semiconductor laser from the relationship graph is described below with reference to fig. 4 together with fig. 5.

Specifically, as can be seen from fig. 4 above, in the case where the semiconductor laser is in the first stage of aging, shallow level defects are generated in the active region of the semiconductor laser.

As the semiconductor laser ages further, deep level defects are generated in the N-type waveguide layer of the semiconductor laser when the semiconductor laser is in the second aging stage.

From the above, the defect distribution information of the semiconductor laser can be obtained by the relation graph of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process, and the defect distribution information obtained by the method is more accurate than the defect distribution information obtained according to the relation graph of the capacitance and the frequency.

Fig. 6 is a flowchart of a defect identifying method of a semiconductor laser according to a third embodiment of the present invention.

Referring to fig. 6, a defect identifying method of a semiconductor laser according to a third embodiment of the present invention includes step S610, step S620, step S630, and step S640.

Specifically, in step S610, a first graph (shown in fig. 2A and 2B) of the relationship between the capacitance and the frequency of the semiconductor laser during the aging process is obtained.

Further, in step S620, the defect level information of the semiconductor laser is acquired according to the first relation graph. Step S610 and step S620 are the same as step S310 and step S320, respectively, and are not described herein again.

Next, in step S630, a second relation graph (shown in fig. 4) of the apparent carrier concentration and the depletion region width of the semiconductor laser in the aging process is acquired.

Finally, in step S640, the defect distribution information of the semiconductor laser is obtained according to the second relation graph. Step S630 and step S640 are the same as step S510 and step S520, respectively, and are not described herein again.

Fig. 7 is a schematic structural diagram of an exemplary structure of a semiconductor laser according to the present invention.

Referring to fig. 7, an exemplary structure of a semiconductor laser according to the present invention includes: an N-type layer 101A, an active layer 105, and a P-type layer 101B are sequentially stacked on the substrate 101.

Specifically, the N-type layer 101A includes, in order from the substrate 101 to the active layer 101B, an N-type AlGaN confining layer 102, an N-type GaN waveguide layer 103, and an N-type InGaN waveguide layer 104, which are stacked. Specifically, defects mainly occur in the N-type GaN waveguide layer 103.

The active layer 105 includes a GaN barrier layer 1051, an InGaN quantum well layer 1052, and a GaN barrier layer 1051 stacked in this order from the N-type layer 101A to the P-type layer 101B.

The P-type layer 101B includes a P-type InGaN waveguide layer 106, a P-type AlGaN confinement layer 107, and a P-type GaN contact layer 108 sequentially stacked on the active layer 105.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results.

The terminology used in the description of the one or more embodiments is for the purpose of describing the particular embodiments only and is not intended to be limiting of the description of the one or more embodiments. As used in one or more embodiments of the present specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in one or more embodiments of the present description to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of one or more embodiments herein. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

The above description is only for the purpose of illustrating the preferred embodiments of the one or more embodiments of the present disclosure, and is not intended to limit the scope of the one or more embodiments of the present disclosure, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the one or more embodiments of the present disclosure should be included in the scope of the one or more embodiments of the present disclosure.