VCSEL luminous point and VCSEL chip

Abstract

The invention discloses a VCSEL (Vertical Cavity Surface Emitting Laser) luminous point and a VCSEL chip. The VCSLE luminous point comprises at least one oxidation limiting layer and at least one flow guide hole, the oxidation limiting layer is provided with an oxidation limiting hole, each circulation hole at least partially extends to the oxidation limiting hole, the flow guide hole is provided with a first tail end and a second tail end, the first tail end and the second tail end are mutually spaced, and a reserved vacancy is formed between the first tail end and the second tail end of the flow guide hole; wherein the flow guide hole is located on the outer side of the oxidation limiting hole, and the side wall, facing the oxidation limiting hole, of the flow guide hole is in an arc shape.

Description

Technical Field

[0001] The present application relates to the field of semiconductor lasers, and more specifically to a VCSEL light emitting point and a VCSEL chip. Background Art

[0002] VCSEL (Vertical-Cavity Surface-Emitting Laser) is a semiconductor laser that forms a resonant cavity in the vertical direction of the substrate and emits laser in the vertical direction. VCSEL has the characteristics of stable beam quality, single longitudinal mode output, and high photoelectric conversion efficiency. It is widely used in communications, consumer, automotive and other fields.

[0003] The VCSEL laser mainly includes a substrate layer, an N-DBR layer and a P-DBR layer stacked on the substrate layer, an active region sandwiched between the N-DBR layer and the P-DBR layer, and a restriction layer located on the upper side and / or the lower side of the active region. At present, the restriction layer is mainly formed by an oxidation process. Specifically, the structural layer used to form the restriction layer is oxidized, and an oxidizing fluid, such as water vapor, enters the structural layer from the outer edge of the structural layer, and the area close to the outer edge of the structural layer is oxidized to form a restriction area, and the unoxidized area forms a restriction hole.

[0004] In the conventional process, in the process of forming the VCSLE laser, an epitaxial structure is first formed, wherein the epitaxial structure includes, from bottom to top, a substrate layer, an N-DBR structure layer, an active region structure layer, and a P-DBR structure layer; then, a light exit hole is defined; then, the epitaxial structure is etched, and portions of some structural layers in the epitaxial structure surrounding the light exit hole are removed to form a mesa structure; then, the mesa structure is selectively oxidized to form the confinement layer.

[0005] In the process of forming the mesa structure, a whole circle of material around the light exit hole is removed, so that the oxidation hole formed in the subsequent oxidation process of the mesa structure is closer to a circle. However, such a design scheme makes the distance between two adjacent VCSEL lasers larger when forming a VCSEL array including multiple VCSEL lasers, and the arrangement of each VCSEL laser in the VCSEL array is not compact, and the overall volume of the VCSEL array is larger, which does not meet the requirements of device miniaturization. Summary of the invention

[0006] One advantage of the present application is that it provides a VCSEL light-emitting point and a VCSEL chip, wherein the present application provides a scheme for forming an oxidation restriction layer, and the shape of the restriction hole can be controlled by designing the extension direction of the peripheral wall of the hole structure extending to the structural layer used to form the oxidation restriction layer, so that the shape of the restriction hole finally formed is close to the expected shape of the restriction hole.

[0007] Another advantage of the present application is that it provides a VCSEL light emitting point and a VCSEL chip, wherein the present application controls the shape of the limiting hole so that the shape of the limiting hole in the oxidation limiting layer is close to a circle.

[0008] Another advantage of the present application is that it provides a VCSEL light emitting point and a VCSEL chip, wherein the present application reduces the sharpness of the turning corner of the outer edge of the limiting hole in the oxidation limiting layer by controlling the shape of the limiting hole, thereby improving the reliability of the VCSEL laser.

[0009] In order to achieve at least one of the above advantages or other advantages and purposes, according to one aspect of the present application, a VCSEL light-emitting point is provided, which includes:

[0010] at least one oxidation limiting layer, the oxidation limiting layer having an oxidation limiting pore; and

[0011] At least one flow guide hole, each of the flow holes at least partially extending to the oxidation limiting hole, the flow guide hole having a first end and a second end, the first end and the second end are spaced apart from each other, and a reserved space is formed between the first end and the second end of the flow guide hole;

[0012] Wherein, the guide hole is located outside the oxidation limiting hole, and the side wall of the guide hole facing the oxidation limiting hole is arc-shaped.

[0013] In some embodiments, the VCSEL light-emitting point includes a first guide hole, the cross-section of the first guide hole is semicircular, the central angle corresponding to the first guide hole is greater than 180 degrees, the first guide hole surrounds the oxidation limiting hole, and a reserved space is formed between the first end and the second end of the first guide hole.

[0014] In some embodiments, the VCSEL light-emitting point includes a first guide hole and a second guide hole, the cross-section of the first guide hole is semicircular, the cross-section of the second guide hole is semicircular, the central angle corresponding to the first guide hole is greater than 180 degrees, and the central angle corresponding to the second guide hole is less than 180 degrees; the first guide hole and the second guide hole are circumferentially arranged outside the oxidation limiting hole; the first end of the second guide hole is adjacent to the first end of the first guide hole and spaced from each other, forming a first reserved space between the two; the second end of the second guide hole is adjacent to the second end of the first guide hole and spaced from each other, forming a second reserved space between the two.

[0015] In some embodiments, a distance between a first end of the first flow guiding hole and a first end of the second flow guiding hole is equal to a distance between a second end of the first flow guiding hole and a second end of the second flow guiding hole.

[0016] In some embodiments, the VCSEL light-emitting point includes a first guide hole and a second guide hole, the cross-section of the first guide hole is semicircular, the cross-section of the second guide hole is semicircular, the central angle corresponding to the first guide hole is less than or equal to 180 degrees, and the central angle corresponding to the second guide hole is less than or equal to 180 degrees; the first guide hole and the second guide hole are circumferentially arranged outside the oxidation limiting hole; the first end of the second guide hole is adjacent to the first end of the first guide hole and spaced from each other, forming a first reserved space between the two; the second end of the second guide hole is adjacent to the second end of the first guide hole and spaced from each other, forming a second reserved space between the two.

[0017] In some embodiments, the first guide hole and the second guide hole are symmetrically arranged.

[0018] In some embodiments, a distance between a first end of the first flow guiding hole and a first end of the second flow guiding hole is equal to a distance between a second end of the first flow guiding hole and a second end of the second flow guiding hole.

[0019] In some embodiments, the number of the guide holes is less than or equal to 20.

[0020] According to another aspect of the present application, a VCSEL chip is provided, comprising:

[0021] At least two VCSEL light emitting points as described above.

[0022] In some embodiments, at least two of the VCSEL light-emitting points share a guide hole.

[0023] Further objectives and advantages of the present application will be fully reflected through understanding of the following description and drawings.

[0024] These and other objects, features and advantages of the present application are fully reflected in the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] These and / or other aspects and advantages of the present application will become clearer and easier to understand from the following detailed description of the embodiments of the present application in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of an implementation of a guide hole of a VCSEL light-emitting point according to an embodiment of the present application is illustrated.

[0027] Figure 2 A schematic diagram of another implementation of the guide holes of a VCSEL light-emitting point according to an embodiment of the present application is illustrated.

[0028] Figure 3 A schematic diagram of another implementation of a VCSEL light emitting point according to an embodiment of the present application is illustrated.

[0029] Figure 4 A schematic diagram of another implementation of a VCSEL light emitting point according to an embodiment of the present application is illustrated.

[0030] Figure 5 A schematic diagram of another implementation of a VCSEL light emitting point according to an embodiment of the present application is illustrated. DETAILED DESCRIPTION

[0031] The terms and words used in the following specification and claims are not limited to the literal meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present application. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of the present application is provided for illustration purposes only and not for the purpose of limiting the present application as defined by the appended claims and their equivalents.

[0032] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0033] Although ordinals such as "first," "second," and the like will be used to describe various components, those components are not limited herein. The term is used only to distinguish one component from another. For example, a first component may be referred to as a second component, and likewise, a second component may be referred to as a first component without departing from the teachings of the present application. The term "and / or" as used herein includes any and all combinations of one or more associated listed items.

[0034] The terms used herein are only used for the purpose of describing various embodiments and are not intended to be limiting. As used herein, singular forms are intended to also include plural forms, unless the context clearly indicates an exception. In addition, it will be understood that the terms "including" and / or "having" when used in this specification specify the presence of the described features, numbers, steps, operations, components, elements or combinations thereof, without excluding the presence or addition of one or more other features, numbers, steps, operations, components, elements or groups thereof.

[0035] Application Overview

[0036] As mentioned above, currently, the limiting layer is mainly formed by an oxidation process. Specifically, the structural layer used to form the limiting layer is oxidized, and an oxidizing fluid, such as water vapor, enters the structural layer from the outer edge of the structural layer, and the area near the outer edge of the structural layer is oxidized to form a limiting area, and the unoxidized area forms a limiting hole.

[0037] In the traditional process, the mesa structure is selectively oxidized to form the restriction layer. In the process of forming the mesa structure, a whole circle of material around the light-emitting hole is removed, so that the oxidation hole formed in the subsequent oxidation of the mesa structure is closer to a circle. However, such a design scheme makes the distance between two adjacent VCSEL lasers larger when forming a VCSEL array including multiple VCSEL lasers, and the arrangement of each VCSEL laser in the VCSEL array is not compact, and the overall volume of the VCSEL array is larger, which does not meet the requirements of device miniaturization.

[0038] The inventor of the present application proposes that only part of the material in the circumferential direction of the light emitting hole can be etched to form a hole that only partially surrounds the periphery of the light emitting hole, and the two ends of the hole are spaced apart from each other, and a reserved space is formed between the two ends. The VCSEL laser adjacent to the reserved space can be relatively close to the VCSEL laser, so as to improve the flexibility of the distance design between adjacent VCSEL lasers and make the arrangement of each VCSEL laser more compact.

[0039] In addition, the inventors of the present application noticed that the peripheral wall of the hole has a guiding effect on the oxidizing fluid, so that the oxidizing fluid flows and diffuses inward from the outer edge of the structural layer along the extension direction of the peripheral wall of the hole, and impregnates the structural layer used to form the restriction layer, and oxidizes the structural layer used to form the restriction layer along a specific direction. In this way, a restriction hole is formed in the hole structure.

[0040] Based on this, the inventors of the present application proposed to control the flow direction of the oxidation fluid by designing the extension direction of the peripheral wall of the hole extending to the structural layer used to form the oxidation restriction layer, thereby controlling the shape of the restriction hole finally formed.

[0041] After introducing the basic principles of the present application, various non-limiting embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0042] Schematic VCSEL light emitting point

[0043] like Figures 1 to 5 As shown, the VCSEL light-emitting point according to the embodiment of the present application is explained. In the embodiment of the present application, a single VCSEL light-emitting point is a single VCSEL laser. The VCSEL light-emitting point has a multi-layer structure layer, mainly including a substrate layer, an N-DBR layer, a P-DBR layer, an active region sandwiched between the N-DBR layer and the P-DBR layer, and an oxidation restriction layer located on the upper side of the active region and / or the lower side of the active region, and the oxidation restriction layer has an oxidation restriction hole 101.

[0044] In an embodiment of the present application, the VCSEL laser further comprises at least one guide hole, each of which at least partially extends to the oxidation restriction layer. Specifically, the guide hole extends from the upper surface of the VCSEL laser to below the active region, that is, below the bottom surface of the active region.

[0045] For example, when the substrate layer, the N-DBR layer, the active area, the oxidation restriction layer and the P-DBR layer are arranged from bottom to top, the guide hole extends from the P-DBR layer to the N-DBR layer below the active area, and the guide hole passes through the oxidation restriction layer; for another example, when the substrate layer, the P-DBR layer, the active area, the oxidation restriction layer and the N-DBR layer are arranged from bottom to top, the guide hole extends from the N-DBR layer to the P-DBR layer below the active area, and the guide hole passes through the oxidation restriction layer.

[0046] The guide hole has a first end and a second end, and a reserved space is formed between the first end and the second end, so that each VCSEL laser is arranged more compactly. In the process of forming the oxidation restriction layer, the guide hole is formed at the periphery of the position where the oxidation restriction hole 101 is pre-formed in the structural layer used to form the oxidation restriction layer; subsequently, an oxidation fluid is introduced into the guide hole, and the oxidation fluid enters the interior of the structural layer used to form the oxidation restriction layer from the guide hole; the portion of the structural layer used to form the oxidation restriction layer that is oxidized by the oxidation fluid forms a restriction area, and the unoxidized portion of the interior forms the oxidation restriction hole 101; the final performance is: the guide hole is located outside the oxidation restriction hole 101.

[0047] It is worth mentioning that the peripheral wall of the guide hole has a guiding effect on the oxidation fluid. In the process of forming the oxidation restriction layer, the oxidation fluid flows along the extension direction of the peripheral wall of the guide hole and diffuses to the surroundings. Accordingly, in the embodiment of the present application, the flow direction of the oxidation fluid is regulated by designing the extension direction of the peripheral wall of the guide hole, thereby regulating the shape of the oxidation restriction hole 101 finally formed.

[0048] It is also worth mentioning that when a turning angle appears at the outer edge of the oxidation limiting hole 101 and the sharpness of the turning angle is large, the number of currents gathered at the intersection is large, resulting in a much higher current density at the intersection than the surrounding area, resulting in a higher local thermal effect, which reduces the reliability of the VCSEL laser. Therefore, it is expected that the oxidation limiting hole 101 finally formed is close to a circle, so that the sharpness of the turning angle of the outer edge of the oxidation limiting hole 101 in the oxidation limiting layer is reduced, thereby improving the reliability of the VCSEL laser. The present application proposes to design the side wall of the guide hole facing the oxidation limiting hole 101 to be arc-shaped.

[0049] The shapes of other side walls of the guide hole with an arc-shaped side wall facing the oxidation limiting hole 101 are not limited by the present application. Accordingly, the overall shape of the guide hole with an arc-shaped side wall facing the oxidation limiting hole 101 is not limited by the present application.

[0050] In the implementation of this application, if Figures 1 to 5 As shown, the overall shape of the guide hole whose side wall facing the oxidation limiting hole 101 is designed to be arc-shaped is a semicircular ring.

[0051] The number and distribution of the guide holes are not limited by the present application. For example, in one embodiment of the application, the number of guide holes of a single VCSEL light-emitting point is 1; accordingly, in this embodiment, the VCSEL light-emitting point includes a first guide hole 11, and the cross-section of the first guide hole 11 is semicircular. In this embodiment, Figure 1As shown, the central angle corresponding to the first guide hole 11 is greater than 180 degrees, and the first guide hole 11 surrounds the oxidation limiting hole 101. A reserved space is formed between the first end and the second end of the first guide hole 11, so that the VCSEL light-emitting point adjacent to the reserved space can be relatively close to the VCSEL light-emitting point, so that the various VCSEL light-emitting points can be arranged more compactly.

[0052] In another embodiment of the present application, the number of guide holes of a single VCSEL light-emitting point is 2; accordingly, in this embodiment, the VCSEL light-emitting point includes a first guide hole 11 and a second guide hole 12, the cross section of the first guide hole 11 is semicircular, and the cross section of the second guide hole 12 is semicircular. Figure 2 and Figure 3 As shown, the central angle corresponding to the first guide hole 11 is greater than 180 degrees, and the central angle corresponding to the second guide hole 12 is less than 180 degrees; the first guide hole 11 and the second guide hole 12 are circumferentially arranged outside the oxidation limiting hole 101; the first end of the second guide hole 12 is adjacent to the first end of the first guide hole 11 and spaced apart from each other, forming a first reserved space between the two; the second end of the second guide hole 12 is adjacent to the second end of the first guide hole 11 and spaced apart from each other, forming a second reserved space between the two.

[0053] Optionally, in this embodiment, the distance between the first end of the first flow guiding hole 11 and the first end of the second flow guiding hole 12 is equal to the distance between the second end of the first flow guiding hole 11 and the second end of the second flow guiding hole 12 .

[0054] In another embodiment of the present application, the number of guide holes of a single VCSEL light-emitting point is 2; accordingly, in this embodiment, the VCSEL light-emitting point includes a first guide hole 11 and a second guide hole 12, the cross section of the first guide hole 11 is semicircular, and the cross section of the second guide hole 12 is semicircular. Figure 4 As shown, the central angle corresponding to the first guide hole 11 is less than or equal to 180 degrees, and the central angle corresponding to the second guide hole 12 is less than or equal to 180 degrees; the first guide hole 11 and the second guide hole 12 are circumferentially arranged outside the oxidation limiting hole 101; the first end of the second guide hole 12 is adjacent to the first end of the first guide hole 11 and spaced apart from each other, forming a first reserved space between the two; the second end of the second guide hole 12 is adjacent to the second end of the first guide hole 11 and spaced apart from each other, forming a second reserved space between the two.

[0055] Optionally, in this embodiment, the first flow guiding holes 11 and the second flow guiding holes 12 are symmetrically arranged.

[0056] Optionally, in this embodiment, the distance between the first end of the first flow guiding hole 11 and the first end of the second flow guiding hole 12 is equal to the distance between the second end of the first flow guiding hole 11 and the second end of the second flow guiding hole 12 .

[0057] In another embodiment of the present application, the number of the guide holes is equal to 3. Figure 5 As shown, the VCSEL light-emitting point includes a first guide hole 11, a second guide hole 12 and a third guide hole 13. The cross section of the first guide hole 11 is semicircular, the cross section of the second guide hole 12 is semicircular, and the cross section of the third guide hole 13 is semicircular. The central angle corresponding to the first guide hole 11 is less than 180 degrees, the central angle corresponding to the second guide hole 12 is less than 90 degrees, and the central angle corresponding to the third guide hole 13 is less than 90 degrees; the first guide hole 11, the second guide hole 12 and the third guide hole 13 are circumferentially arranged outside the oxidation limiting hole 101; the first end of the second guide hole 12 is adjacent to the first end of the first guide hole 11 and is spaced apart from each other, forming a first reserved space between the two; the second end of the second guide hole 12 is adjacent to the first end of the third guide hole 13 and is spaced apart from each other, forming a second reserved space between the two; the second end of the third guide hole 13 is adjacent to the second end of the first guide hole 11 and is spaced apart from each other, forming a third reserved space between the two.

[0058] In some embodiments of the present application, the number of the guide holes is less than or equal to 3. It should be understood that in other embodiments of the present application, the number of the guide holes may be other values, for example, the number of the guide holes may be less than or equal to 20.

[0059] Accordingly, the present application proposes a VCSEL chip, which includes at least two VCSEL light-emitting points as described above. Optionally, at least two of the VCSEL light-emitting points share at least one guide hole, so that the arrangement between the VCSEL light-emitting points is more compact.

[0060] In summary, based on the VCSEL light-emitting points and VCSEL chips of the embodiments of the present application, the present application provides a scheme for forming an oxidation restriction layer, which can control the shape of the restriction hole by designing the extension direction of the peripheral wall of the hole structure extending to the structural layer used to form the oxidation restriction layer, so that the shape of the restriction hole finally formed is close to the expected shape of the restriction hole.

[0061] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

Claims

1. A VCSEL light emitting point, characterized in that: include: at least one oxidation restriction layer, the oxidation restriction layer having an oxidation restriction hole; and At least one flow guide hole, each of the flow holes at least partially extending to the oxidation limiting hole, the flow guide hole having a first end and a second end, the first end and the second end are spaced apart from each other, and a reserved space is formed between the first end and the second end of the flow guide hole; Wherein, the guide hole is located outside the oxidation limiting hole, and the side wall of the guide hole facing the oxidation limiting hole is arc-shaped.

2. The VCSEL light emitting point according to claim 1, wherein: The VCSEL light-emitting point includes a first guide hole, the cross-section of the first guide hole is semicircular, the central angle corresponding to the first guide hole is greater than 180 degrees, the first guide hole surrounds the oxidation limiting hole, and a reserved space is formed between the first end and the second end of the first guide hole.

3. The VCSEL light emitting point according to claim 1, wherein: The VCSEL light-emitting point includes a first guide hole and a second guide hole, the cross-section of the first guide hole is semicircular, the cross-section of the second guide hole is semicircular, the central angle corresponding to the first guide hole is greater than 180 degrees, and the central angle corresponding to the second guide hole is less than 180 degrees; the first guide hole and the second guide hole are circumferentially arranged outside the oxidation limiting hole; the first end of the second guide hole is adjacent to the first end of the first guide hole and spaced from each other, forming a first reserved space between the two; the second end of the second guide hole is adjacent to the second end of the first guide hole and spaced from each other, forming a second reserved space between the two.

4. The VCSEL light emitting point according to claim 3, wherein: The distance between the first end of the first flow guiding hole and the first end of the second flow guiding hole is equal to the distance between the second end of the first flow guiding hole and the second end of the second flow guiding hole.

5. The VCSEL light emitting point according to claim 1, wherein: The VCSEL light-emitting point includes a first guide hole and a second guide hole, the cross-section of the first guide hole is semicircular, the cross-section of the second guide hole is semicircular, the central angle corresponding to the first guide hole is less than or equal to 180 degrees, and the central angle corresponding to the second guide hole is less than or equal to 180 degrees; the first guide hole and the second guide hole are circumferentially arranged outside the oxidation limiting hole; the first end of the second guide hole is adjacent to the first end of the first guide hole and is spaced from each other, and a first reserved space is formed between the two; the second end of the second guide hole is adjacent to the second end of the first guide hole and is spaced from each other, and a second reserved space is formed between the two.

6. The VCSEL light emitting point according to claim 5, wherein: The first guide hole and the second guide hole are symmetrically arranged.

7. The VCSEL light emitting point according to claim 5, wherein: The distance between the first end of the first flow guiding hole and the first end of the second flow guiding hole is equal to the distance between the second end of the first flow guiding hole and the second end of the second flow guiding hole.

8. The VCSEL light emitting point according to claim 1, wherein: The number of the guide holes is less than or equal to 20.

9. A VCSEL chip, characterized in that: include: At least two VCSEL light-emitting points according to any one of claims 1 to 8.

10. The VCSEL chip according to claim 9, wherein: At least two of the VCSEL light-emitting points share a guide hole.

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