A vertical cavity surface emitting laser and an electronic device having the same

Abstract

The present disclosure provides a vertical cavity surface emitting laser and an electronic device having the same, the vertical cavity surface emitting laser comprising a first electrode layer, a substrate layer, a first reflector layer, a light emitting layer, a second reflector layer, a high-contrast grating layer and a second electrode layer which are stacked; the high-contrast grating layer comprises an oxide spacer layer, a grating layer, a grating isolation groove and a passivation layer, wherein the grating isolation groove surrounds the high-contrast grating on the grating layer, and the penetration depth of the grating isolation groove reaches at least the inside of the oxide spacer layer, and the passivation layer covers the outer surfaces of the oxide spacer layer, the grating layer and the grating isolation groove. The vertical cavity surface emitting laser of the present disclosure can effectively protect the high-contrast grating, increase the mechanical stability, prolong the service life of the laser, and has strong reliability.

Description

Technical Field

[0001] This disclosure generally relates to the field of optoelectronic device technology, and specifically to a vertical cavity surface-emitting laser and an electronic device having the same. Background Technology

[0002] Vertical cavity surface emitting lasers (VCSELs) have many advantages, such as small size, low power consumption, easy integration and high coupling efficiency, and can be widely used in optical communication, 3D sensing and lidar.

[0003] In VCSELs with a high contrast grating (HCG) structure, the oxide spacer layer of the HCG structure is relatively loose and its volume decreases during oxidation, which can lead to separation from the adjacent layer material. This reduces the mechanical properties of the HCG and affects the lifespan of the laser. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the related technologies, it is desirable to provide a vertical cavity surface-emitting laser and an electronic device thereon, which can effectively protect the high-contrast grating, increase mechanical stability, extend the life of the laser, and have high reliability.

[0005] In a first aspect, this disclosure provides a vertical cavity surface-emitting laser, the vertical cavity surface-emitting laser comprising a first electrode layer, a substrate layer, a first reflector layer, a light-emitting layer, a second reflector layer, a high-contrast grating layer, and a second electrode layer stacked together. The high-contrast grating layer includes an oxide spacer layer, a grating layer, a grating isolation trench, and a passivation layer. The oxide spacer layer is located between the grating layer and the second reflector layer. The second electrode layer is located on the surface of the grating layer facing away from the oxide spacer layer. The grating layer includes a high-contrast grating. The grating isolation trench surrounds the high-contrast grating on the grating layer, and the penetration depth of the grating isolation trench reaches at least into the interior of the oxide spacer layer. The grating isolation trench is in the form of a two-stage stepped structure, including a first stepped portion and a second stepped portion disposed vertically. The first stepped portion is located in the second electrode layer, and the depth of the first stepped portion is equal to the thickness of the second electrode layer. The second stepped portion is at least partially located in the high-contrast grating layer, and the depth of the second stepped portion can reach at least into the interior of the oxide spacer layer. The passivation layer covers the outer surface of the oxide spacer layer, the outer surface of the grating layer, and the outer surface of the grating isolation trench.

[0006] Optionally, in some embodiments of this disclosure, the surrounding shape of the grating isolation groove includes either a circle or a polygon.

[0007] Optionally, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating is located inside the oxide spacer layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

[0008] Optionally, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating is located on the upper surface of the oxide spacer layer; Alternatively, the bottom of the grating groove is located on the lower surface of the oxide spacer layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

[0009] Optionally, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating is located inside the second reflector layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

[0010] Optionally, in some embodiments of this disclosure, the light-emitting layer includes an active layer and an oxide layer stacked together, the oxide layer including an unoxidized region for emitting laser light and an oxidized region surrounding the unoxidized region.

[0011] Optionally, in some embodiments of this disclosure, the high-contrast grating includes a periodic grating or a non-periodic grating.

[0012] Optionally, in some embodiments of this disclosure, the high-contrast grating includes either a one-dimensional grating structure or a two-dimensional grating structure.

[0013] Optionally, in some embodiments of this disclosure, the passivation layer includes SiO2, SiN, TiO2, and AlO2. x At least one of the materials.

[0014] In a second aspect, this disclosure provides an electronic device comprising a vertical-cavity surface-emitting laser as described in any one of the first aspects.

[0015] As can be seen from the above technical solutions, the embodiments disclosed herein have the following advantages: This disclosure provides a vertical-cavity surface-emitting laser (VCSEL) and an electronic device thereon. By setting a grating isolation trench around a high-contrast grating in the grating layer, with the trench penetrating at least into the interior of the oxide spacer layer, stability and reliability are ensured. Simultaneously, a passivation layer is applied to the outer surfaces of the oxide spacer layer, the grating layer, and the grating isolation trench to isolate moisture and oxygen from the air, effectively protecting the high-contrast grating and extending the laser's lifespan. Furthermore, the grating isolation trench increases the tolerance of subsequent processes, significantly improving the laser's production yield. Attached Figure Description

[0016] Other features, objects, and advantages of this disclosure will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 A schematic cross-sectional structure diagram of a vertical cavity surface-emitting laser (VCSEL) based on related technologies; Figure 2 This is a cross-sectional structural diagram of a vertical cavity surface-emitting laser provided in an embodiment of the present disclosure; Figure 3 A scanning electron microscope schematic diagram of a high-contrast grating and grating isolation groove in a vertical cavity surface-emitting laser provided for embodiments of this disclosure; Figure 4 A cross-sectional structural schematic diagram of another vertical cavity surface-emitting laser provided in this embodiment of the present disclosure; Figure 5 A cross-sectional structural schematic diagram of another vertical cavity surface-emitting laser provided in this disclosure embodiment; Figure 6 A cross-sectional structural schematic diagram of another vertical cavity surface-emitting laser provided in the embodiments of this disclosure; Figure 7 A cross-sectional structural schematic diagram of a vertical cavity surface-emitting laser provided in another embodiment of this disclosure; Figure 8 This is a structural block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present disclosure.

[0018] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in this disclosure, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such use of data can be interchanged where appropriate so that the embodiments of this disclosure described can be implemented in orders other than those illustrated or described herein.

[0019] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or device that includes a series of steps or modules is not necessarily limited to those steps or modules that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such process, method, product, or device.

[0020] To facilitate a better understanding of this disclosure, the following is provided: Figure 1 The following is an example of a cross-sectional structural diagram of a vertical-cavity surface-emitting laser (VCSEL) in the related technology. Figure 1 As shown, the vertical-cavity surface-emitting laser 1 of the related technology includes a negative electrode 11, a substrate 12, a first reflector layer 13, a light-emitting structure 14, a second reflector layer 15, a high-contrast grating structure 16, and a positive electrode 17. From... Figure 1 It can be seen that, due to the relatively loose structure of the oxide region 161 of the high-contrast grating and the smaller volume during oxidation, there is an undesirable phenomenon of separation from the adjacent layer material, which reduces the mechanical properties of the high-contrast grating and affects the lifespan of the laser.

[0021] Therefore, this disclosure provides a vertical-cavity surface-emitting laser and an electronic device having the same, which will be described below. Figures 2 to 8 To elaborate in detail.

[0022] Please refer to Figure 2 This is a cross-sectional structural diagram of a vertical cavity surface-emitting laser (VCSEL) provided in an embodiment of the present disclosure. The VCSEL 2 includes a first electrode layer 21, a substrate layer 22, a first reflector layer 23, a light-emitting layer 24, a second reflector layer 25, a high-contrast grating layer 26, and a second electrode layer 27 stacked together.

[0023] It should be noted that, in this embodiment of the present disclosure, the high-contrast grating layer 26 includes an oxide spacer layer 261, a grating layer 262, a grating isolation trench 263, and a passivation layer 264. An oxide spacer layer 261 is located between the grating layer 262 and the second reflector layer 23. The second electrode layer 25 is located on the surface of the grating layer 262 facing away from the oxide spacer layer 261. The grating layer 262 includes a high-contrast grating 2621. A grating isolation groove 263 surrounds the high-contrast grating 2621 on the grating layer 262, and the penetration depth of the grating isolation groove 263 can reach at least the interior of the oxide spacer layer 261, ensuring stability and reliability. It also increases the tolerance of subsequent processes, greatly improving the production yield of the laser. A passivation layer 264 covers the outer surface of the oxide spacer layer 261, the outer surface of the grating layer 262, and the outer surface of the grating isolation groove 263. This arrangement has the advantage of isolating water vapor and oxygen in the air, effectively protecting the high-contrast grating 2621 and extending the lifespan of the laser.

[0024] It should be noted that the grating isolation groove 263 is in the form of a two-stage step, including a first step and a second step set at the top and bottom. The first step is located in the second electrode layer 27, and the depth of the first step is equal to the thickness of the second electrode layer 27. The second step is at least partially located in the high contrast grating layer 26, and the depth of the second step can at least reach the interior of the oxide spacer layer 261.

[0025] Optionally, in this embodiment of the present disclosure, the surrounding shape of the grating isolation groove 263 includes any one of a circle and a polygon. For example, a circle includes, but is not limited to, a perfect circle and an ellipse, while a polygon includes, but is not limited to, a square and a rectangle. For example, as shown... Figure 3 The high-contrast grating 2621 shown is circular, and the grating isolation groove 263 is annular.

[0026] Optionally, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating 2621 may be located inside the oxide spacer layer 261, while the bottom of the grating isolation groove 263 may be located inside the second reflector layer 25 (e.g., Figure 2 (As shown), it can also be located inside the oxide spacer layer 261 (as shown). Figure 4 As shown in the figure, the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove 263.

[0027] Alternatively, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating 2621 can be located on the upper surface of the oxide spacer layer 261 (e.g., Figure 5 As shown), it can also be located on the lower surface of the oxide spacer layer 261 (as shown). Figure 6 As shown in the figure, the bottom of the grating isolation groove 263 can be located inside the second reflector layer 25, in which case the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove 263.

[0028] Alternatively, in some embodiments of this disclosure, the bottom of the grating groove of the high-contrast grating 2621 can be located inside the second reflector layer 25 (e.g. Figure 7 As shown in the figure, the bottom of the grating isolation groove 263 can be located inside the second reflector layer 25, in which case the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove 263.

[0029] It should be noted that, considering the etching loading effect, the penetration depth of the grating isolation groove 263 in this embodiment is greater than the penetration depth of the grating groove. Additionally, the width of the grating isolation groove 263 in this embodiment can also be greater than the width of the grating groove.

[0030] Optionally, the high-contrast grating 2621 in this embodiment includes, but is not limited to, a periodic grating or an aperiodic grating. Furthermore, the high-contrast grating 2621 includes, but is not limited to, any one-dimensional grating structure and a two-dimensional grating structure. Therefore, the grating isolation groove 263 can be adapted to different high-contrast grating designs, meeting diverse application scenarios and offering high flexibility.

[0031] Optionally, the passivation layer 264 in this embodiment includes, but is not limited to, SiO2, SiN, TiO2, and AlO2. x At least one of the materials.

[0032] Optionally, in the embodiments of this disclosure, the first electrode layer 21 and the second electrode layer 27 include one of an N-type electrode layer and a P-type electrode layer. For example, the first electrode layer 21 is an N-type electrode layer and the second electrode layer 27 is a P-type electrode layer; or, for another example, the first electrode layer 21 is a P-type electrode layer and the second electrode layer 27 is an N-type electrode layer.

[0033] Optionally, in this embodiment of the present disclosure, the first reflector layer 23 and the second reflector layer 25 include one of an N-type reflector layer and a P-type reflector layer. For example, the first reflector layer 23 is an N-type reflector layer and the second reflector layer 25 is a P-type reflector layer; or, for another example, the first reflector layer 23 is a P-type reflector layer and the second reflector layer 25 is an N-type reflector layer. Further, the first reflector layer 23 and the second reflector layer 25 can be distributed Bragg reflector (DBR) layers.

[0034] Optionally, in this embodiment of the present disclosure, the light-emitting layer 24 includes an active layer 241 and an oxide layer 242 stacked together, wherein the oxide layer 242 includes an unoxidized region 2421 for emitting laser light and an oxidized region surrounding the unoxidized region 2422. Further, the active layer 241 may include either a single quantum well layer or a multiple quantum well (MQW) layer for stimulated emission under energized conditions.

[0035] It should be noted that the oxide layer 242 forms a structure that is conductive in the middle and insulating on the outside through oxidation, thereby limiting the current and allowing more current to flow into the middle part of the active layer 241, increasing the carrier concentration, thereby obtaining a greater differential gain and increasing the modulation bandwidth of the laser.

[0036] The vertical-cavity surface-emitting laser provided in this disclosure features a grating isolation trench around a high-contrast grating in the grating layer. The trench penetrates at least into the interior of the oxide spacer layer, ensuring stability and reliability. Furthermore, a passivation layer covers the outer surfaces of the oxide spacer layer, the grating layer, and the grating isolation trench to isolate moisture and oxygen from the air, effectively protecting the high-contrast grating and extending the laser's lifespan. Additionally, the grating isolation trench increases the tolerance for subsequent processes, significantly improving the laser's production yield.

[0037] Based on the foregoing embodiments, please refer to Figure 8 This is a structural block diagram of an electronic device provided in an embodiment of the present disclosure. The electronic device 3 includes... Figures 2-7 The vertical-cavity surface-emitting laser 2 corresponds to this embodiment. For example, the electronic device 3 may include, but is not limited to, optical modules and integrated optoelectronic chips.

[0038] The electronic device provided in this disclosure features a vertical-cavity surface-emitting laser (VCSEL) with stable and reliable operation. This is achieved by creating grating isolation trenches around a high-contrast grating in the grating layer, with the trenches penetrating at least into the interior of the oxide spacer layer. Furthermore, passivation layers are applied to the outer surfaces of the oxide spacer layer, the grating layer, and the grating isolation trenches to isolate them from moisture and oxygen in the air. This effectively protects the high-contrast grating and extends the laser's lifespan. Additionally, the grating isolation trenches increase the tolerance of subsequent processes, significantly improving the laser's production yield.

[0039] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A vertical-cavity surface-emitting laser, characterized in that, The vertical cavity surface-emitting laser includes a first electrode layer, a substrate layer, a first reflector layer, a light-emitting layer, a second reflector layer, a high-contrast grating layer, and a second electrode layer stacked together. The high-contrast grating layer includes an oxide spacer layer, a grating layer, a grating isolation trench, and a passivation layer. The oxide spacer layer is located between the grating layer and the second reflector layer. The second electrode layer is located on the surface of the grating layer facing away from the oxide spacer layer. The grating layer includes a high-contrast grating. The grating isolation trench surrounds the high-contrast grating on the grating layer, and the penetration depth of the grating isolation trench reaches at least into the interior of the oxide spacer layer. The grating isolation trench is in the form of a two-stage stepped structure, including a first stepped portion and a second stepped portion disposed vertically. The first stepped portion is located in the second electrode layer, and the depth of the first stepped portion is equal to the thickness of the second electrode layer. The second stepped portion is at least partially located in the high-contrast grating layer, and the depth of the second stepped portion can reach at least into the interior of the oxide spacer layer. The passivation layer covers the outer surface of the oxide spacer layer, the outer surface of the grating layer, and the outer surface of the grating isolation trench.

2. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The shape of the grating isolation groove can be either circular or polygonal.

3. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The bottom of the grating groove of the high-contrast grating is located inside the oxide spacer layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

4. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The bottom of the grating groove of the high-contrast grating is located on the upper surface of the oxide spacer layer; Alternatively, the bottom of the grating groove is located on the lower surface of the oxide spacer layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

5. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The bottom of the grating groove of the high-contrast grating is located inside the second reflector layer, and the penetration depth of the grating groove is less than the penetration depth of the grating isolation groove.

6. The vertical-cavity surface-emitting laser according to any one of claims 1 to 5, characterized in that, The light-emitting layer includes an active layer and an oxide layer stacked together. The oxide layer includes an unoxidized region for emitting laser light and an oxidized region surrounding the unoxidized region.

7. The vertical cavity surface emitting laser of claim 6, wherein, The high-contrast grating includes a periodic grating or a non-periodic grating.

8. The vertical cavity surface emitting laser of claim 6, wherein, The high-contrast grating includes either a one-dimensional grating structure or a two-dimensional grating structure.

9. The vertical cavity surface emitting laser of claim 6, wherein, The passivation layer includes SiO2, SiN, TiO2, and AlO2. x At least one of the materials.

10. An electronic device, characterized in that, The electronic device includes a vertical cavity surface-emitting laser as described in any one of claims 1 to 9.

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