VCSEL chip, preparation method of VCSEL chip, optical module and optical emission assembly of optical module

Abstract

The invention discloses a VCSEL chip and a preparation method thereof, an optical module and a light emitting assembly thereof, the VCSEL chip comprises a VCSEL device, the VCSEL device comprises a substrate, a bottom reflector structure, a resonant cavity structure and a top reflector structure, and the substrate, the bottom reflector structure, the resonant cavity structure and the top reflector structure are sequentially distributed; and the heating device is arranged at the bottom position of the VCSEL device, and the heating device is in contact with the substrate. The VCSEL chip comprises the VCSEL device and the heating device, the heating device is arranged at the bottom of the VCSEL device, the heating device can actively heat the VCSEL device, the heating device at the bottom can avoid heat loss, and a better heat preservation effect is achieved. When the outside is in a low-temperature environment, the VCSEL device can be always kept in a proper temperature range through active heating of the heating device, and the situation that the transmission performance of the VCSEL device is reduced due to increase of low-temperature internal resistance is avoided, that is, the transmission performance of the VCSEL device can still be ensured in the low-temperature environment through the arrangement of the heating device, so that normal work in the low-temperature environment is achieved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor light-emitting components, and particularly to a VCSEL chip, a preparation method thereof, an optical module and an optical emission component thereof. Background Art

[0002] With the continuous development of the field of high-speed optical communication technology, VCSEL (Vertical Cavity Surface Emitting Laser) is widely used in multimode optical modules. An optical emission component is a component in an optical network terminal (ONT) for converting an electrical signal into an optical signal, which mainly includes a laser, a driving circuit for driving the laser, and the like.

[0003] The optical network terminal is required to be able to work in an environment of -40°C to 85°C. The internal resistance of the VCSEL increases with the decrease of temperature. Therefore, the requirement for the temperature range that the laser in the optical emission component can adapt to is relatively high. At present, how to eliminate the influence of the VCSEL internal resistance on the low-temperature environment to improve the transmission performance of the VCSEL in the low-temperature environment is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The present invention provides a VCSEL chip, a preparation method thereof, an optical module and an optical emission component thereof, which are used to solve the problem that the VCSEL cannot work normally in a low-temperature environment.

[0005] In one embodiment, a VCSEL chip is provided, including: A VCSEL device, the VCSEL device includes a substrate, a bottom mirror structure, a resonant cavity structure and a top mirror structure which are distributed in sequence, and the resonant cavity structure is used to generate a standing wave; and A heating device, the heating device is arranged at the bottom position of the VCSEL device, the heating device is in contact with the substrate, and the heating device is used to heat the VCSEL device; Wherein, the substrate is provided with a heat preservation structure having a heat preservation cavity, and at least part of the heat preservation cavity is located in the area between the heating device and the bottom mirror structure, and the heat preservation structure is used to accommodate the heat generated by the heating device.

[0006] In one embodiment, the heat preservation structure is an annular groove, a connecting part is arranged in the middle of the annular groove, and the heating device is connected to the connecting part.

[0007] In one embodiment, the vertical cross-section of the connecting portion is an inverted T-shaped structure. The connecting portion includes a vertical connecting column and a horizontal connecting plate. The vertical connecting column is located in the middle of the annular groove, and the horizontal connecting plate is located outside the annular groove. The heating device is connected to the horizontal connecting plate.

[0008] In one embodiment, the heat insulation structure includes one or more heat insulation grooves, and the heat insulation grooves extend along a straight line and / or a curve.

[0009] In one embodiment, the heat insulation structure includes one or more heat insulation cavities, and the heat insulation cavities are located in the substrate.

[0010] In one embodiment, the heat insulation cavity of the heat insulation structure is filled with a heat-conducting medium.

[0011] In one embodiment, the heating device is a flat structure, the heating device has a heating surface, and the heating surface is in contact with the bottom surface of the substrate facing away from the bottom mirror structure.

[0012] In one embodiment, the heating device is a metal heating device or a semiconductor heating device.

[0013] In one embodiment, the resonant cavity structure includes at least one active layer and at least one optical confinement layer. The optical confinement layer is disposed adjacent to the active layer, and the optical confinement layer is configured to define the light-emitting region of the VCSEL chip.

[0014] In one embodiment, a groove is provided on the bottom surface of the substrate, and part or all of the heating device is located in the groove.

[0015] In one embodiment, a heat-conducting layer is provided between the substrate and the heating device.

[0016] In one embodiment, at least two VCSEL devices are included. The substrates of at least two VCSEL devices are connected into an integral structure, and each VCSEL device is correspondingly provided with at least one heating device.

[0017] In one embodiment, a method for manufacturing a VCSEL chip is provided, including the following steps: Form an epitaxial layer on a substrate by an epitaxial process. The epitaxial layer sequentially includes a bottom mirror structure, a resonant cavity structure, and a top mirror structure; Fabricate a heating device on the side of the substrate facing away from the epitaxial layer.

[0018] In one embodiment, it further includes: Perform step etching and deep trench etching on the epitaxial layer respectively; Perform wet oxidation on the epitaxial layer through the deep trench.

[0019] forming a first electrode structure electrically connected to the bottom reflector structure on the exposed surface of the bottom reflector structure; A second electrode structure electrically connected to the top reflector structure is formed on a surface of the top reflector structure.

[0020] In one embodiment, before the step of manufacturing a heating device on a side of the substrate facing away from the epitaxial layer, the step further includes: A heat preservation structure having a heat preservation cavity is prepared on a side of the substrate facing away from the epitaxial layer, and at least a portion of the heat preservation cavity is located in a region between the heating device and the bottom reflector structure.

[0021] In one embodiment, the heat preservation cavity is manufactured by performing a dry etching and / or a wet etching process on the substrate.

[0022] In one embodiment, a light emitting component for an optical module is provided, comprising a driver and at least one of the above-mentioned VCSEL chips electrically connected to the driver.

[0023] In one embodiment, an optical module and a method for preparing the same are provided, including a light emitting component, wherein the light emitting component adopts the above-mentioned light emitting component for the optical module.

[0024] According to a VCSEL chip and its preparation method, an optical module and its optical emission component in the above-mentioned embodiment, since the VCSEL chip includes a VCSEL device and a heating device, the heating device is arranged at the bottom of the VCSEL device, and the heating device can actively heat the VCSEL device. The heating device located at the bottom can also prevent heat loss and achieve a better thermal insulation effect. When the outside world is in a low-temperature environment, the active heating of the heating device can keep the VCSEL device within a suitable temperature range at all times, avoiding the transmission performance degradation of the VCSEL device due to the increase of the low-temperature internal resistance, that is, the setting of the heating device can ensure that the VCSEL device can still guarantee its transmission performance in a low-temperature environment, so as to achieve normal operation in a low-temperature environment; The VCSEL chip of this embodiment can directly integrate a heating device on the original VCSEL device using semiconductor technology, which can reduce the volume and manufacturing cost of the heating device; and can improve the response speed of the heating device during heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional schematic diagram of a VCSEL chip in an embodiment; Figure 2 A bottom view of a VCSEL chip in one embodiment; Figure 3Schematic cross-sectional view of a VCSEL chip in an embodiment; Figure 4 Schematic cross-sectional view of a VCSEL chip in an embodiment; Figure 5 Schematic cross-sectional view of a VCSEL chip in an embodiment; Figure 6 Bottom view of a VCSEL chip in an embodiment; Figure 7 Schematic cross-sectional view of a VCSEL chip in an embodiment; Figure 8 Schematic cross-sectional view of a VCSEL chip in an embodiment; Figure 9 Flowchart of a method for manufacturing a VCSEL chip in an embodiment; Figure 10 Flowchart of a method for manufacturing a VCSEL chip in an embodiment.

[0026] The reference numerals are as follows: 1 - VCSEL device, 11 - substrate, 111 - groove, 112 - thermal insulation structure, 1121 - thermal insulation cavity, 113 - connecting part, 114 - thermal conductive medium, 12 - bottom mirror structure, 13 - resonant cavity structure, 131 - active layer, 132 - optical confinement layer, 14 - top mirror structure, 15 - first electrode structure, 16 - second electrode structure; 2 - heating device; 3 - thermal conductive layer. Detailed implementation manners

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings through specific implementation manners. Similar elements in different implementation manners are labeled with related similar reference numerals. In the following implementation manners, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0028] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean a necessary sequence, unless it is stated otherwise that a certain sequence must be followed.

[0029] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any sequential or technical meaning. And as used in this application, "connection" and "coupling", unless otherwise specified, both include direct and indirect connection (coupling).

[0030] In one embodiment, a VCSEL chip is provided. The VCSEL chip is an important component in the optical emission component of an optical module. Among them, the VCSEL chip mainly includes a VCSEL device. The VCSEL device refers to a vertical cavity surface emitting laser (VCSEL) composed of a multi-layer PN junction stacked structure, and the VCSEL device is used to generate and emit laser light. This VCSEL chip also includes a heating device. The heating device is arranged at the bottom position of the VCSEL device. The heating device is an active heating device, and the heating device can actively heat the VCSEL device, so that the VCSEL device is always maintained within a suitable temperature range, which can avoid the degradation of the transmission performance caused by the increase of the low-temperature internal resistance of the VCSEL device in a low-temperature environment, that is, it can avoid the failure or malfunction of the VCSEL device in a low-temperature environment, and enable the VCSEL device to work normally in a low-temperature environment. For example, the VCSEL device can still work normally at -40 degrees Celsius. In an environment where the temperature of the VCSEL device is relatively high, the heating device can be turned off to avoid overheating of the VCSEL device.

[0031] Please refer to Figure 1 and Figure 2 , in this embodiment, the VCSEL chip mainly includes a VCSEL device 1 and a heating device 2. The heating device 2 is arranged at the bottom position of the VCSEL device 1. The top of the VCSEL device 1 is used to emit laser light. The heating device 2 located at the bottom of the VCSEL device 1 does not affect the laser emission of the VCSEL device 1. The VCSEL device 1 covers the heating device 2, and heat preservation can be achieved by using the VCSEL device 1 to avoid heat loss.

[0032] The VCSEL device 1 mainly includes a substrate 11, a bottom mirror structure 12, a resonant cavity structure 13, and a top mirror structure 14 that are distributed in sequence from bottom to top. The resonant cavity structure 13 is limited by the bottom mirror structure 12 and the top mirror structure 14, that is, the area between the bottom mirror structure 12 and the top mirror structure 14 is the resonant cavity. The resonant cavity is used to generate a standing wave, which is a wave formed by two coherent waves propagating in opposite directions along the same straight line and superimposing on each other. Specifically, when the phases of the two waves are the same, their amplitudes are added to form a wave belly (i.e., a wave crest). When the phases of the two waves are opposite, their amplitudes are subtracted to form a wave node (i.e., a wave trough). Therefore, the positions of the wave crests and wave troughs of the standing wave are fixed.

[0033] The substrate 11 is located at the bottom of the VCSEL device 1. The material of the substrate 11 is a non-laser-transmitting material, including but not limited to GaAs, InP, Si, etc. The substrate 11 is used to prevent the laser generated by the VCSEL device 1 from exiting from the lower end of the VCSEL device 1. The bottom mirror structure 12 and the top mirror structure 14 can include film layers with periodically varying refractive indices to achieve efficient reflection or transmission of light within a specific wavelength range. The film layers with periodically varying refractive indices can be composed of semiconductor materials, dielectric materials, metal-dielectric hybrid materials, etc. The bottom mirror structure 12 can be an N-type semiconductor layer, and the top mirror structure 14 can be a P-type semiconductor layer. The materials of the N-type semiconductor layer and the P-type semiconductor layer can include but not limited to GaAs, AlGaAs, etc., which are not limited here as long as they can limit the resonant cavity and fall within the protection scope of this embodiment.

[0034] In other embodiments, the bottom mirror structure 12 can also be a P-type semiconductor layer, and the top mirror structure 14 can also be an N-type semiconductor layer.

[0035] In this embodiment, the resonant cavity structure 13 can include a plurality of active layers 131 stacked and at least one optical confinement layer 132. For example, the number of active regions can be 2, 3, 4, etc. The number of active layers 131 can be selected according to the usage requirements. The plurality of active layers 131 can emit light simultaneously, enabling effective superposition of photons and meeting the requirements of signal transmission.

[0036] The active layer 131 is used to generate stimulated emission photons, and the emitted photons are continuously reflected in the resonant cavity defined by the bottom mirror structure 12 and the top mirror structure 14 and continuously enhanced during the reflection process, so as to finally emit laser light at a specific wavelength and with sufficient energy.

[0037] The number of the optoelectronic confinement layers 132 is generally not greater than that of the active regions, for example, it can be 2, 3, etc. A plurality of optoelectronic confinement layers 132 and a plurality of active regions are arranged alternately up and down. The optoelectronic confinement layer 132 is usually an oxidation confinement layer, which is obtained by oxidizing a P-DBR (Distributed Bragg Reflector) with a high aluminum component. The optoelectronic confinement layer 132 can also be a tunnel junction type, an air column type, or an ion implantation type confinement layer. The optoelectronic confinement layer 132 is used to define the light-emitting region of the VCSEL device 1, and the optoelectronic confinement layer 132 is used to restrict the flow of current, so that the current only flows within the region defined by the optoelectronic confinement layer 132, thereby reducing energy consumption and increasing the current density. The optoelectronic confinement layer 132 can also confine the optical field within the light-emitting region defined by the optoelectronic confinement layer 132, reduce the scattering and diffraction of light, improve the beam quality, and improve the signal transmission quality.

[0038] In this embodiment, the VCSEL device 1 further includes a first electrode structure 15 and a second electrode structure 16. The first electrode structure 15 can be disposed on the bottom mirror structure 12; the second electrode structure 16 can be disposed on the top mirror structure 14. When the bottom mirror structure 12 is connected to an N-type semiconductor layer, the first electrode structure 15 is a negative electrode structure. When the top mirror structure 14 is connected to a P-type semiconductor layer, the second electrode structure 16 is a positive electrode structure; or, when the bottom mirror structure 12 is connected to a P-type semiconductor layer, the first electrode structure 15 is a positive electrode structure. When the top mirror structure 14 is connected to an N-type semiconductor layer, the second electrode structure 16 is a negative electrode structure. The first electrode structure 15 and the second electrode structure 16 are used to connect to a power supply circuit, and the first electrode structure 15 and the second electrode structure 16 are used to power on the VCSEL device 1 to generate laser light.

[0039] In this embodiment, the heating device 2 is disposed at the bottom position of the VCSEL device 1, and the VCSEL device 1 covers the heating device 2. The heating device 2 heats the VCSEL device 1 from the bottom, and the VCSEL device 1 covering the heating device 2 has a better heat preservation effect. Of course, the VCSEL device 1 can also cover a part of the heating device 2, and the heating device 2 can realize heating the VCSEL device 1 from the bottom. Among them, the heating device 2 is located at the middle position at the bottom of the VCSEL device 1, which can enable the VCSEL device 1 to more effectively absorb the heat generated by the heating device 2 and avoid heat dissipation.

[0040] Specifically, the VCSEL device 1 is a cylindrical structure, and the heating device 2 can also be a cylindrical structure. The outer diameter of the heating device 2 is smaller than the outer diameter of the VCSEL device 1, and the center lines of the two are aligned and overlapped. Of course, the outer diameter of the heating device 2 can also be equal to the outer diameter of the VCSEL device 1 to achieve more efficient heating.

[0041] The heating device 2 can be, including but not limited to, a metal heating device or a semiconductor heating device, etc. For example, the heating device 2 can be a TiN heating device, a W heating device, a Cu heating device, etc.

[0042] The heating device 2 is preferably of a flat structure. The heating device 2 has a relatively large heating surface area and a relatively thin thickness. For example, the thickness of the TiN heating device is 100 nm. The heating surface of the heating device 2 can be directly attached to the bottom surface of the substrate 11 facing away from the bottom mirror structure 12. The heating device 2 is in direct contact with the bottom surface of the substrate 11, and the heating device 2 and the substrate 11 can be fixed by means such as bonding. The heat generated by the heating device 2 is directly transferred to the substrate 11 to heat the VCSEL device 1. The relatively thin thickness of the heating device 2 can reduce the overall height and volume of the VCSEL chip, and can also enable the VCSEL device 1 to completely cover the heating device 2. There is a small gap around the heating device 2 arranged at the bottom of the VCSEL device 1, which can improve the heat preservation effect and avoid heat loss.

[0043] Please refer to Figure 3 , in other embodiments, a heat conduction layer 3 can be provided between the heating device 2 and the substrate 11. The heat conduction layer 3 can assist the heating device 2 in transferring heat to the substrate 11. Among them, the heat conduction layer 3 can also be a unidirectional heat conduction structure composed of materials such as carbon / carbon composite. The unidirectional heat conduction structure can transfer the heat from the heating device 2 to the substrate 11 and block the heat transfer from the substrate 11 to the heating device 2, so as to achieve a better heating effect.

[0044] In other embodiments, the top and around of the VCSEL device 1 can be covered with a heat preservation layer. The heat preservation layer can be a heat preservation structure such as a heat preservation film. The heat preservation layer can effectively avoid the heat loss generated by the heating device 2 and provide the heating and heat preservation effect of the VCSEL chip.

[0045] In this embodiment, since the VCSEL chip includes the VCSEL device 1 and the heating device 2, and the heating device 2 is arranged at the bottom position of the VCSEL device 1, the heating device 2 can actively heat the VCSEL device 1. The heating device 2 located at the bottom can also avoid heat loss and play a better heat preservation role. When the external environment is in a low-temperature environment, the active heating of the heating device 2 can keep the VCSEL device 1 always within a suitable temperature range, avoiding the decline of the transmission performance of the VCSEL device 1 due to the increase of the internal resistance at low temperature. That is, the setting of the heating device 2 can enable the VCSEL device 1 to still ensure its transmission performance in a low-temperature environment to achieve normal operation in a low-temperature environment.

[0046] The VCSEL chip of this embodiment can directly integrate the heating device 2 on the original VCSEL device 1 by using semiconductor processes, which can reduce the volume of the heating device 2 and the manufacturing cost; moreover, the response speed of the heating device 2 during heating can be improved.

[0047] Please refer to Figure 4 , in one embodiment, a groove 111 can be provided on the bottom surface of the substrate 11 of the VCSEL device 1, and a part of the heating device 2 is located in the groove 111. With such a setting, the contact area between the heating device 2 and the substrate 11 can be increased, improving the heating efficiency; at the same time, the substrate 11 wraps the heating device 2, which can effectively reduce the heat loss generated by the heating device 2.

[0048] In one embodiment, the entire heating device 2 can also be embedded in the groove 111 of the substrate 11, maximizing the contact area between the heating device 2 and the substrate 11 and further reducing heat loss.

[0049] In one embodiment, a plurality of heating devices 2 are provided on the bottom surface of the substrate 11 of the VCSEL device 1, and the plurality of heating devices 2 are evenly distributed on the bottom surface of the substrate 11. With such a setting, the bottom surface of the substrate 11 covers more heating devices 2, that is, the contact area between the heating device 2 and the substrate 11 is increased, which can effectively improve the heating efficiency and also achieve a more uniform heating effect.

[0050] Please refer to Figure 5 and Figure 6 , in one embodiment, the substrate 11 is provided with a heat insulation structure 112, the heat insulation structure 112 has a heat insulation cavity 1121, and at least part of the heat insulation cavity 1121 of the heat insulation structure 112 is located in the region between the heating device 2 and the bottom mirror structure 12. Among them, the heat insulation cavity 1121 of the heat insulation structure 112 can be filled with air, and air has the characteristic of low thermal conductivity, which can concentrate the heat at the lower position of the VCSEL device 1, that is, the heat insulation structure 112 can be used to hold the heat generated by the heating device 2, reduce heat dissipation, and improve the heating efficiency and heat preservation time in a low-temperature environment.

[0051] The heat insulation structure 112 can be a groove structure, with an opening provided on the bottom surface of the substrate 11, and the opening communicates with the heat insulation cavity 1121 of the heat insulation structure 112. With such a setting, it is convenient for the processing of the heat insulation structure 112 and at the same time allows air to enter the heat insulation cavity 1121 of the heat insulation structure 112. The groove-structured heat insulation structure 112 can be processed by dry etching or wet etching and other methods.

[0052] The heat insulation structure 112 is preferably an annular groove, and a connecting portion 113 is provided in the middle of the annular groove. The heating device 2 is connected to the connecting portion 113. With such an arrangement, the heat insulation structure 112 can be distributed around the heating device 2, which can improve the heat insulation effect.

[0053] Specifically, the vertical cross-section of the connecting portion 113 can be an inverted T-shaped structure. The connecting portion 113 includes a vertical connecting column and a horizontal connecting plate. The vertical connecting column is located in the middle of the annular groove, and the horizontal connecting plate is located outside the annular groove. That is, the vertical connecting column is arranged along the direction of the emitted laser of the VCSEL device 1, and the horizontal connecting plate is perpendicular to the direction of the emitted laser of the VCSEL device 1. The heating device 2 is connected to the horizontal connecting plate. Setting the connecting portion 113 as an inverted T-shaped structure can ensure that the heating device 2 has sufficient contact area with the substrate 11, and can also extend most of the heat insulation cavity 1121 of the heat insulation structure 112 above the heating device 2, which can greatly improve the heating efficiency and heat insulation time in a low-temperature environment.

[0054] In one embodiment, the heat insulation structure 112 can also be other structures. For example, the heat insulation structure 112 includes one or more linear heat insulation grooves, and the linear heat insulation grooves extend along a straight line and / or a curve. The linear heat insulation grooves also have a heat insulation cavity 1121, which can play a heat insulation role.

[0055] In one embodiment, the heat insulation structure 112 can also be a heat insulation cavity. The heat insulation cavity is located in the substrate 11, and the heat insulation cavity has a closed heat insulation cavity 1121, which can also improve the heating efficiency and heat insulation time in a low-temperature environment.

[0056] Please refer to Figure 7 , in one embodiment, a heat conduction medium 114 is filled in the heat insulation cavity 1121 of the heat insulation structure 112. The heat conduction medium 114 can be a substance with high heat conduction performance. For example, a solidified substance filled with metal powder is filled. The heat conduction medium 114 can improve the heating efficiency in a low-temperature environment. At the same time, the heat conduction medium 114 is different from the substrate 11 material, forming a multi-layer heat insulation effect, which can improve the heat insulation time.

[0057] Please refer to Figure 8 , in one embodiment, the VCSEL chip includes at least two VCSEL devices 1, and the at least two VCSEL devices 1 are connected into an integrated structure. Among them, the substrates 11 of the at least two VCSEL devices 1 are an integrated structure, and the bottom mirror structures 12 of the at least two VCSEL devices 1 can also be an integrated structure.

[0058] At least two VCSEL devices 1 can be distributed and arranged in an array, for example, to form a 4×4 array distribution. Each VCSEL device 1 is correspondingly provided with at least one heating device 2. For example, one VCSEL device 1 is correspondingly provided with one heating device 2, so that each VCSEL device 1 has an independent heating device 2 for heating and heat preservation, ensuring that all the VCSEL devices 1 on the VCSEL chip can work normally in a low-temperature environment.

[0059] In one embodiment, there is provided an optical emission component for an optical module. This optical emission component includes a driver and at least one VCSEL chip in any of the above embodiments. The driver is connected to the VCSEL chip, and the driver is used to drive the VCSEL devices 1 on the VCSEL chip to generate and emit laser light. Among them, the optical emission component is a part of the optical module, and the optical emission component is used to convert an electrical signal into an optical signal to realize data transmission through light.

[0060] For the optical emission component for an optical module in this embodiment, since the VCSEL chip is provided with the heating device 2, the optical emission component can maintain good transmission performance in a low-temperature environment, thereby ensuring the quality of optical communication.

[0061] In one embodiment, there is provided an optical module. The optical module in this embodiment includes the above-mentioned optical emission component for an optical module. The optical module emits an optical signal through the optical emission component to transmit a signal.

[0062] Among them, since the VCSEL chip is provided with the heating device 2, the optical module can maintain good transmission performance in a low-temperature environment, thereby ensuring the quality of optical communication.

[0063] In one embodiment, there is provided a preparation method for a VCSEL device. This preparation method is used to prepare the above-mentioned VCSEL chip. The VCSEL chip includes a VCSEL device 1 and a heating device 2. The VCSEL device 1 includes a substrate 11, a bottom mirror structure 12, a resonant cavity structure 13, and a top mirror structure 14.

[0064] Please refer to Figure 9 , in this embodiment, the preparation method of the VCSEL device mainly includes the following steps: S10: Use an epitaxial process to form an epitaxial layer on the substrate. The epitaxial layer sequentially includes a bottom mirror structure, a resonant cavity structure, and a top mirror structure; In this embodiment, a bottom mirror structure, a resonant cavity structure 13, and a top mirror structure are sequentially formed on a substrate by an epitaxial process to fabricate a VCSEL device 1. The epitaxial process may include, but is not limited to, metal organic chemical vapor deposition (MOCVD), molecular layer epitaxy (MLE), or atomic layer deposition (ALD), etc. A wafer of VCSEL with a multi-layer structure grown thereon is obtained, that is, the VCSEL device 1 is obtained.

[0065] Among them, the bottom mirror structure 12, the resonant cavity structure 13, and the top mirror structure 14 are sequentially formed on the substrate one by one through the epitaxial process.

[0066] S20: Fabricate a heating device on the side of the substrate facing away from the epitaxial layer; In the steps of this method, a heating device 2 is fabricated on the side of the substrate 11 facing away from the epitaxial layer by a deposition process. Based on the VCSEL device 1, the heating device 2 is obtained, and the heating device 2 and the VCSEL device 1 form an integrated structure.

[0067] Specifically, a heating device 2 is fabricated on the bottom surface (the side facing away from the epitaxial layer) of the substrate 11 of the VCSEL device 1 by a deposition process. The heating device 2 can be a heating layer. The deposition process includes at least one of sputtering coating, ion plating, electroless plating, chemical vapor deposition, thermal spraying, evaporation plating, and electroplating.

[0068] Preferably, the VCSEL device 1 is fabricated into a cylindrical structure, and the heating device 2 is also fabricated into a cylindrical structure. The heating device 2 is located at the middle position of the bottom of the VCSEL device 1. The outer diameter of the heating device 2 is smaller than the outer diameter of the substrate 11 of the VCSEL device 1, or the outer diameter of the heating device 2 can also be equal to the outer diameter of the substrate 11 of the VCSEL device 1.

[0069] Among them, the thickness and width (diameter) of the heating device 2 will affect the sheet resistance of the heating device. For example, when the fabricated thickness of the heating device 2 is about 100 nm, a thickness change of ±5 nm of the heating device 2 will cause a sheet resistance change of ±0.75 Ω of the heating device 2. Therefore, the thickness and width of the heating device 2 need to be set to reasonable sizes according to the heating requirements, so that the heating device 2 can meet the heating requirements with as small a volume as possible.

[0070] S30: Perform step etching and deep trench etching on the epitaxial layer respectively; Perform step etching and deep trench etching on the epitaxial layer to form steps and trenches on the epitaxial layer, obtaining a number of epitaxial structures. Each epitaxial structure is separated by a trench, and a part of the surface of the bottom mirror structure 12 is exposed by the trench.

[0071] S40: Perform wet oxidation on the epitaxial layer through the deep trench; Adopt a wet oxidation process to oxidize the sidewalls of each epitaxial layer, so that a part of the layer of the top mirror structure 14 is oxidized to form a photoelectric confinement layer.

[0072] S50: Form a first electrode structure electrically connected to the bottom mirror structure on the exposed surface of the bottom mirror structure; In this step: on the exposed surface of the bottom mirror structure 12, first form a passivation layer by a deposition process; make a through hole in the passivation layer, and the through hole exposes the surface of the bottom mirror structure 12; based on the through hole, form a first electrode structure 15, and the first electrode structure 15 is electrically connected to the bottom mirror structure 12; wherein, the first electrode structure 15 can include two, and is used to be electrically connected to adjacent VCSEL devices 1.

[0073] S60: Form a second electrode structure electrically connected to the top mirror structure on the surface of the top mirror structure.

[0074] On the surface of the top mirror structure, form a second electrode structure 16 by a deposition process, and the second electrode structure 16 is electrically connected to the top mirror structure 14. Among them, the second electrode structure 16 can include two, and is used to be electrically connected to adjacent VCSEL devices 1.

[0075] Among them, steps S30 - S60 can be fabricated before or after step S20, and the fabrication sequence can be selected according to requirements.

[0076] For the VCSEL device prepared by this method, the heating device 2 is located at the bottom of the VCSEL device 1. The heating device 2 can actively heat the VCSEL device 1, and the heating device 2 located at the bottom can also avoid heat loss and play a better heat preservation effect. When the external environment is in a low - temperature environment, the active heating of the heating device 2 can keep the VCSEL device 1 always within a suitable temperature range, avoiding the decline of the transmission performance of the VCSEL device 1 due to the increase of the internal resistance at low temperature. That is, the setting of the heating device 2 can enable the VCSEL device 1 to still ensure its transmission performance in a low - temperature environment to achieve normal operation in a low - temperature environment.

[0077] For the VCSEL chip of this embodiment, the heating device 2 can be directly integrated on the original VCSEL device 1 by a semiconductor process, which can reduce the volume of the heating device 2 and the manufacturing cost; and can improve the response speed when the heating device 2 is heating.

[0078] In one embodiment, a method for fabricating a VCSEL device is provided. Before step S20, the following steps are further included: S15, fabricate a thermal insulation structure with a thermal insulation cavity on the side of the substrate facing away from the epitaxial layer, and at least part of the thermal insulation cavity is located in the region between the heating device and the bottom mirror structure.

[0079] In this step, a thermal insulation structure 112 is fabricated on the bottom (the side facing away from the epitaxial layer) of the substrate 11 by using processes such as dry etching and / or wet etching processes. At least part of the thermal insulation structure 112 is located in the region between the heating device 2 and the bottom mirror structure 12.

[0080] The fabricated thermal insulation structure 112 is preferably an annular groove. The thermal insulation structure 112 has a thermal insulation cavity 1121, and the thermal insulation cavity 1121 can be filled with air or a heat-conducting medium, which can effectively improve the thermal insulation effect.

[0081] A reverse T-shaped connecting portion 113 is formed in the middle of the thermal insulation structure 112. The connecting portion 113 includes a vertical connecting column and a horizontal connecting plate. The vertical connecting column is located in the middle of the annular groove, and the horizontal connecting plate is located outside the annular groove, that is, the vertical connecting column is arranged along the direction of the emitted laser of the VCSEL device 1, and the horizontal connecting plate is perpendicular to the direction of the emitted laser of the VCSEL device 1. Among them, forming the connecting portion 113 can be used to fabricate the heating device at the middle position of the bottom of the VCSEL device 1.

[0082] In this embodiment, in step S20, a heating device 2 is fabricated on the horizontal connecting plate of the connecting portion 113 at the bottom of the substrate 11 by using a deposition process. The diameter of the heating device 2 can be equal to or smaller than the diameter of the horizontal connecting plate of the connecting portion 113. The deposition process includes but is not limited to at least one of sputtering coating, ion plating, electroless plating, chemical vapor deposition, thermal spraying, evaporation plating, and electroplating. Among them, preferably, the diameter of the heating device 2 is equal to the diameter of the horizontal connecting plate of the connecting portion 113, so as to fully expand the area of the heating device 2 to obtain a better heating effect.

[0083] For the VCSEL device fabricated by this method, the heating device 2 is located at the bottom of the VCSEL device 1. The heating device 2 can actively heat the VCSEL device 1, and the heating device 2 located at the bottom can also avoid heat loss and play a better thermal insulation effect. When the external environment is in a low-temperature environment, the active heating of the heating device 2 can keep the VCSEL device 1 always within a suitable temperature range, avoiding the decrease in transmission performance caused by the increase in low-temperature internal resistance of the VCSEL device 1. That is, the setting of the heating device 2 can enable the VCSEL device 1 to still ensure its transmission performance in a low-temperature environment to achieve normal operation in a low-temperature environment; Moreover, the heat insulation structure 112 of the substrate 11 can be used to accommodate the heat generated by the heating device 2, reduce heat dissipation, and improve the heating efficiency and heat preservation time in a low-temperature environment.

[0084] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art of the present invention, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A VCSEL chip, characterized in that: include: A VCSEL device, wherein the VCSEL device comprises a substrate, a bottom reflector structure, a resonant cavity structure and a top reflector structure which are sequentially distributed, wherein the resonant cavity structure is used to generate a standing wave; as well as A heating device, wherein the heating device is disposed at the bottom of the VCSEL device, the heating device is in contact with the substrate, and the heating device is used to heat the VCSEL device; The substrate is provided with a heat preservation structure having a heat preservation cavity, at least part of the heat preservation cavity is located in the area between the heating device and the bottom reflector structure, and the heat preservation structure is used to accommodate the heat generated by the heating device.

2. The VCSEL chip according to claim 1, characterized in that: The heat-insulating structure is an annular groove, a connecting portion is provided in the middle of the annular groove, and the heating device is connected to the connecting portion.

3. The VCSEL chip according to claim 2, characterized in that: The vertical cross-section of the connecting portion is an inverted T-shaped structure, and the connecting portion includes a vertical connecting column and a transverse connecting plate. The vertical connecting column is located in the middle of the annular groove, and the transverse connecting plate is located on the outside of the annular groove. The heating device is connected to the transverse connecting plate.

4. The VCSEL chip according to claim 1, characterized in that: The heat-insulating structure comprises one or more heat-insulating grooves, and the heat-insulating grooves are extended along a straight line and / or a curve.

5. The VCSEL chip according to claim 1, characterized in that: The heat preservation structure includes one or more heat preservation cavities, and the heat preservation cavities are located in the substrate.

6. The VCSEL chip according to claim 1, characterized in that: The heat-insulating cavity of the heat-insulating structure is filled with a heat-conducting medium.

7. The VCSEL chip according to claim 1, characterized in that: The heating device is a flat structure and has a heating surface, which is in contact with the bottom surface of the substrate facing away from the bottom reflector structure.

8. The VCSEL chip according to claim 7, characterized in that: The heating device is a metal heating device or a semiconductor heating device.

9. The VCSEL chip according to claim 1, characterized in that: The resonant cavity structure includes at least one active layer and at least one optoelectronic confinement layer, wherein the optoelectronic confinement layer is disposed adjacent to the active layer and configured to define a light emitting region of the VCSEL chip.

10. The VCSEL chip according to claim 1, characterized in that: A groove is provided on the bottom surface of the substrate, and part or all of the heating device is located in the groove.

11. The VCSEL chip according to any one of claims 1 to 10, characterized in that: It comprises at least two VCSEL devices, the substrates of at least two VCSEL devices are connected into an integrated structure, and each VCSEL device is correspondingly provided with at least one heating device.

12. A method for preparing a VCSEL chip, characterized in that: The steps include: An epitaxial layer is formed on a substrate by using an epitaxial process, wherein the epitaxial layer sequentially comprises a bottom reflector structure, a resonant cavity structure and a top reflector structure; A heating device is fabricated on a side of the substrate facing away from the epitaxial layer.

13. The method for preparing a VCSEL chip according to claim 12, characterized in that: Also includes: performing step etching and deep trench etching on the epitaxial layer respectively; wet oxidizing the epitaxial layer through the deep trench; forming a first electrode structure electrically connected to the bottom reflector structure on the exposed surface of the bottom reflector structure; A second electrode structure electrically connected to the top reflector structure is formed on a surface of the top reflector structure.

14. The method for preparing a VCSEL chip according to claim 12, characterized in that: Before the step of manufacturing a heating device on a side of the substrate away from the epitaxial layer, the method further comprises: A heat preservation structure having a heat preservation cavity is prepared on a side of the substrate facing away from the epitaxial layer, and at least a portion of the heat preservation cavity is located in a region between the heating device and the bottom reflector structure.

15. The method for preparing a VCSEL chip according to claim 14, characterized in that: The heat preservation cavity is manufactured by performing a dry etching and / or a wet etching process on the substrate.

16. A light emitting component, characterized in that: The method comprises a driver and at least one VCSEL chip according to any one of claims 1 to 11 electrically connected to the driver.

17. An optical module, characterized in that: It comprises a light emitting component and a light receiving component, wherein the light emitting component adopts the light emitting component as claimed in claim 16.

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