VCSEL laser light source capable of conducting in partition mode and manufacturing method and driving method thereof

文档序号:1834019 发布日期:2021-11-12 浏览:11次 中文

阅读说明:本技术 可分区导通的vcsel激光光源及其制备方法和驱动方法 (VCSEL laser light source capable of conducting in partition mode and manufacturing method and driving method thereof ) 是由 林珊珊 郭铭浩 李念宜 王立 姚毅飞 李姗姗 郝宇杰 于 2020-04-24 设计创作,主要内容包括:本申请提供一种可分区导通的VCSEL激光光源、制备方法及驱动方法。该光源包括:VCSEL阵列;形成于所述VCSEL阵列顶部的顶部电导通图案,以及,形成于所述VCSEL阵列底部的底部电导通图案。所述VCSEL阵列,包括相互电隔离的多个VCSEL单元,其中每一VCSEL单元自下而上包括衬底、底部反射器、有源区、具有开孔的限制层、顶部反射器和欧姆接触层。所述底部电导通图案包括第一电导通图案和第二电导通图案,其中所述第一电导通图案电连接于所述多个VCSEL单元中的第一子集,以及,所述第二电导通图案电连接于所述多个VCSEL单元中的第二子集。这样,所述激光光源通过负极布线的方式实现分区导通,以解决散热难题并能够适应不同的应用场景。(The application provides a VCSEL laser light source capable of being conducted in a partitioned mode, a preparation method and a driving method. The light source includes: a VCSEL array; a top electrical conduction pattern formed on top of the VCSEL array, and a bottom electrical conduction pattern formed on bottom of the VCSEL array. The VCSEL array comprises a plurality of VCSEL units which are electrically isolated from each other, wherein each VCSEL unit comprises a substrate, a bottom reflector, an active region, a limiting layer with an opening, a top reflector and an ohmic contact layer from bottom to top. The bottom electrical conduction pattern includes a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units. Therefore, the laser light source realizes partition conduction in a negative wiring mode, so that the problem of heat dissipation is solved, and different application scenes can be adapted.)

1. A sectionally conductive VCSEL laser source, comprising:

a VCSEL array comprising a plurality of VCSEL units electrically isolated from each other, wherein each VCSEL unit comprises, from bottom to top, a substrate, a bottom reflector, an active region, a confinement layer having an aperture, a top reflector, and an ohmic contact layer, an upper surface of the ohmic contact layer of each VCSEL unit comprising a top electrical contact region of each VCSEL unit;

a top electrical conduction pattern formed on top of said VCSEL array, wherein said top electrical conduction pattern is electrically connected to top electrical contact regions of all of said VCSEL units in said VCSEL array; and

a bottom electrical conduction pattern formed at a bottom of the VCSEL array, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

2. A VCSEL laser light source in accordance with claim 1, wherein the VCSEL units in common are absent from the first and second subsets.

3. A VCSEL laser light source in accordance with claim 1, wherein the first subset includes all of the VCSEL cells in the second subset.

4. A VCSEL laser light source in accordance with claim 1, wherein the bottom electrical conduction pattern further comprises a third electrical conduction pattern electrically connected to a third subset of the plurality of VCSEL units.

5. A VCSEL laser light source as in any of claims 1-4, wherein the VCSEL array has a plurality of isolation trenches formed respectively between every two VCSEL units, each isolation trench extending upwardly from the substrate and through the substrate and the bottom reflector and reaching a bottom of the top electrically conductive pattern to electrically isolate the VCSEL units from each other through the isolation trenches.

6. A VCSEL laser light source as in any of claims 1-4, wherein the VCSEL array further comprises an isolation medium between each two VCSEL units and dopingly formed in the substrate and the bottom reflector of each VCSEL unit.

7. The VCSEL laser light source of claim 6, whereinThe isolating medium is selected from high-energy implantation doping of H, He, C, O and N, the energy is in the MeV level, and the dosage is 1011-15

8. A method for preparing a VCSEL laser light source is characterized by comprising the following steps:

forming an epitaxial structure, wherein the epitaxial structure sequentially comprises a substrate, a bottom reflector, an active region, a limiting layer, a top reflector and an ohmic contact layer from bottom to top;

forming a plurality of mesa structures on the epitaxial structure by an etching process, each of the mesa structures including, from bottom to top, the active region, the confinement layer, the top reflector, and the ohmic contact layer, wherein the ohmic contact layer includes a top electrical contact region formed on an upper surface thereof;

oxidizing the confinement layer of each mesa structure by an oxidation process such that the confinement layer has an opening of a particular pore size;

depositing a dielectric insulating layer on the mesa structure, wherein the dielectric insulating layer covers the upper surface of the substrate, a bottom region of the mesa structure, and other regions of the ohmic contact layer except for the top electrical contact region;

forming a top electrical conduction pattern on an upper surface of the ohmic contact layer, wherein the top electrical conduction pattern is electrically connected to the top electrical contact regions of all of the mesa structures;

etching the substrate and the bottom reflector to form an isolation trench between each two of the mesa structures to separately form a plurality of VCSEL units through the isolation trench, wherein the isolation trench extends upward from the substrate and penetrates through the substrate and the bottom reflector and reaches the bottom of the top electrically conductive pattern, respectively, and each of the VCSEL units includes, from bottom to top, the substrate, the bottom reflector, the active region, the confinement layer having an opening, the top reflector, and the ohmic contact layer; and

forming a bottom electrical conduction pattern on a lower surface of the substrate, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

9. The manufacturing method according to claim 8, wherein forming a bottom electrically conductive pattern electrically connected to the substrate on a lower surface of the substrate comprises:

thinning the substrate;

forming an electric connection glue layer on the lower surface of the substrate; and

adhering and electrically connecting the bottom electrically conductive pattern to the electrical connection glue layer.

10. A method for preparing a VCSEL laser light source is characterized by comprising the following steps:

forming an epitaxial structure, wherein the epitaxial structure sequentially comprises a substrate, a bottom reflector, an active region, a limiting layer, a top reflector and an ohmic contact layer from bottom to top;

forming a plurality of mesa structures on the epitaxial structure by an etching process, each of the mesa structures including, from bottom to top, the active region, the confinement layer, the top reflector, and the ohmic contact layer, wherein the ohmic contact layer includes a top electrical contact region formed on an upper surface thereof;

oxidizing the confinement layer of each mesa structure by an oxidation process such that the confinement layer has an opening of a particular pore size;

implanting an isolation medium between every two of the mesa structures, wherein the isolation medium is formed on the substrate and the bottom reflector in a doped manner to form a plurality of VCSEL units separated by the isolation medium, and each VCSEL unit comprises the substrate, the bottom reflector, the active region, the limiting layer with the opening, the top reflector and the ohmic contact layer from bottom to top;

depositing a dielectric insulating layer on the mesa structure, wherein the dielectric insulating layer covers the upper surface of the substrate, a bottom region of the mesa structure, and other regions of the ohmic contact layer except for the top electrical contact region;

forming a top electrical conduction pattern on an upper surface of the ohmic contact layer, wherein the top electrical conduction pattern is electrically connected to the top electrical contact regions of all of the mesa structures; and

forming a bottom electrical conduction pattern on a lower surface of the substrate, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

11. The production method according to claim 10, wherein forming a bottom electrically conductive pattern electrically connected to the substrate on a lower surface of the substrate comprises:

thinning the substrate;

forming an electric connection glue layer on the lower surface of the substrate; and

adhering and electrically connecting the bottom electrically conductive pattern to the electrical connection glue layer.

12. A driving method of a VCSEL laser light source for turning on the VCSEL laser light source according to any of claims 1 to 7, comprising:

a first electrical conduction pattern of a bottom electrical conduction pattern in the VCSEL laser light source is turned on at a first control current such that a first subset of a plurality of VCSEL units in the VCSEL laser light source are turned on.

13. The driving method according to claim 12, further comprising:

turning on a second electrical conduction pattern of the bottom electrical conduction pattern in the VCSEL laser light source at a second control current such that a second subset of the plurality of VCSEL cells in the VCSEL laser light source are turned on.

14. The driving method according to claim 13, wherein the first control current and the second control current have different current magnitudes.

Technical Field

The present application relates to the field of semiconductor technologies, and more particularly, to a VCSEL laser light source suitable for conducting partitioned conduction, and a manufacturing method and a driving method thereof.

Background

A VCSEL (Vertical-Cavity Surface-Emitting Laser) refers to a semiconductor Laser that forms a resonant Cavity in the Vertical direction of a substrate and emits Laser light in the Vertical direction. The VCSEL laser has a good dynamic single mode, and is widely applied in the fields of optical communication, optical storage, laser display, illumination and the like.

In practical applications, VCSEL lasers are usually integrated in the form of VCSEL arrays, which represent optoelectronic devices capable of generating two or more laser beams. As the number of VCSEL lasers included in the VCSEL array increases, the power of the VCSEL array gradually increases, on one hand, the heat productivity of the high-power VCSEL array is large, and on the premise of not fully dissipating heat, the performance of a chip can be influenced; on the other hand, the electrode routing of an increasing number of VCSEL arrays becomes more complicated and difficult, especially for VCSEL lasers located in the middle region of the VCSEL array.

Therefore, a new VCSEL array is needed.

Content of application

One advantage of the present application is to provide a VCSEL laser source capable of being conducted in a partitioned manner, and a method for manufacturing the VCSEL laser source and a method for driving the VCSEL laser source, wherein the VCSEL laser source is wired in a partitioned manner to optimize chip wiring and heat dissipation.

Another advantage of the present application is to provide a VCSEL laser source capable of conducting in a partitioned manner, a manufacturing method thereof, and a driving method thereof, wherein the VCSEL laser source selectively performs a partitioned wiring on a side opposite to a light emitting surface, so as to reduce an influence of the partitioned wiring on a light emitting performance of the VCSEL laser source, and at the same time, reduce a difficulty of the partitioned wiring.

Another advantage of the present application is to provide a VCSEL laser source capable of conducting in a divisional manner, and a manufacturing method and a driving method thereof, wherein the VCSEL laser source is suitable for adopting an adaptive conduction mode based on an application scenario, so that the VCSEL laser source can meet requirements of a plurality of different application scenarios. That is, the VCSEL laser light source has a greater application expandability.

To achieve at least one of the above advantages, the present application provides a VCSEL laser light source that can be turned on in a divided manner, including:

a VCSEL array comprising a plurality of VCSEL units electrically isolated from each other, wherein each VCSEL unit comprises, from bottom to top, a substrate, a bottom reflector, an active region, a confinement layer having an aperture, a top reflector, and an ohmic contact layer, an upper surface of the ohmic contact layer of each VCSEL unit comprising a top electrical contact region of each VCSEL unit;

a top electrical conduction pattern formed on top of said VCSEL array, wherein said top electrical conduction pattern is electrically connected to top electrical contact regions of all of said VCSEL units in said VCSEL array; and

a bottom electrical conduction pattern formed at a bottom of the VCSEL array, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

In the VCSEL laser light source according to the present application, there are no VCSEL units in common in the first subset and the second subset.

In the VCSEL laser light source according to the present application, the first subset comprises all of the VCSEL units in the second subset.

In the VCSEL laser light source according to the present application, the bottom electrical conduction pattern further includes a third electrical conduction pattern electrically connected to a third subset of the plurality of VCSEL units.

In the VCSEL laser light source according to the present application, the VCSEL array has a plurality of isolation grooves respectively formed between every two VCSEL units, each isolation groove respectively extending upward from the substrate and penetrating through the substrate and the bottom reflector and reaching the bottom of the top electrically conductive pattern to electrically isolate the VCSEL units from each other through the isolation grooves.

In the VCSEL laser light source according to the present application, the VCSEL array further includes an isolation medium between each two VCSEL units and doped to the substrate and the bottom reflector of each VCSEL unit.

In the VCSEL laser source according to the present application, the isolation medium is selected from the group consisting of high energy implant doping of H, He, C, O, N, energy MeV level, dose 1011-15

According to another aspect of the present application, there is further provided a method for manufacturing a VCSEL laser light source, including the steps of:

forming an epitaxial structure, wherein the epitaxial structure sequentially comprises a substrate, a bottom reflector, an active region, a limiting layer, a top reflector and an ohmic contact layer from bottom to top;

forming a plurality of mesa structures on the epitaxial structure by an etching process, each of the mesa structures including, from bottom to top, the active region, the confinement layer, the top reflector, and the ohmic contact layer, wherein the ohmic contact layer includes a top electrical contact region formed on an upper surface thereof;

oxidizing the confinement layer of each mesa structure by an oxidation process such that the confinement layer has an opening of a particular pore size;

depositing a dielectric insulating layer on the mesa structure, wherein the dielectric insulating layer covers the upper surface of the substrate, a bottom region of the mesa structure, and other regions of the ohmic contact layer except for the top electrical contact region;

forming a top electrical conduction pattern on an upper surface of the ohmic contact layer, wherein the top electrical conduction pattern is electrically connected to the top electrical contact regions of all of the mesa structures;

etching the substrate and the bottom reflector to form an isolation trench between each two of the mesa structures to separately form a plurality of VCSEL units through the isolation trench, wherein the isolation trench extends upward from the substrate and penetrates through the substrate and the bottom reflector and reaches the bottom of the top electrically conductive pattern, respectively, and each of the VCSEL units includes, from bottom to top, the substrate, the bottom reflector, the active region, the confinement layer having an opening, the top reflector, and the ohmic contact layer; and

forming a bottom electrical conduction pattern on a lower surface of the substrate, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

In a production method according to the present application, forming a bottom electrically conductive pattern electrically connected to the substrate on a lower surface of the substrate includes: thinning the substrate; forming an electric connection glue layer on the lower surface of the substrate; and adhering and electrically connecting the bottom electrically conductive pattern to the electrical connection glue layer.

According to another aspect of the present application, there is provided a method for manufacturing a VCSEL laser light source, including:

forming an epitaxial structure, wherein the epitaxial structure sequentially comprises a substrate, a bottom reflector, an active region, a limiting layer, a top reflector and an ohmic contact layer from bottom to top;

forming a plurality of mesa structures on the epitaxial structure by an etching process, each of the mesa structures including, from bottom to top, the active region, the confinement layer, the top reflector, and the ohmic contact layer, wherein the ohmic contact layer includes a top electrical contact region formed on an upper surface thereof;

oxidizing the confinement layer of each mesa structure by an oxidation process such that the confinement layer has an opening of a particular pore size;

implanting an isolation medium between every two of the mesa structures, wherein the isolation medium is formed on the substrate and the bottom reflector in a doped manner to form a plurality of VCSEL units separated by the isolation medium, and each VCSEL unit comprises the substrate, the bottom reflector, the active region, the limiting layer with the opening, the top reflector and the ohmic contact layer from bottom to top;

depositing a dielectric insulating layer on the mesa structure, wherein the dielectric insulating layer covers the upper surface of the substrate, a bottom region of the mesa structure, and other regions of the ohmic contact layer except for the top electrical contact region;

forming a top electrical conduction pattern on an upper surface of the ohmic contact layer, wherein the top electrical conduction pattern is electrically connected to the top electrical contact regions of all of the mesa structures; and

forming a bottom electrical conduction pattern on a lower surface of the substrate, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units.

In a production method according to the present application, forming a bottom electrically conductive pattern electrically connected to the substrate on a lower surface of the substrate includes: thinning the substrate; forming an electric connection glue layer on the lower surface of the substrate; and adhering and electrically connecting the bottom electrically conductive pattern to the electrical connection glue layer.

According to another aspect of the present application, there is further provided a driving method of a VCSEL laser light source, for turning on the VCSEL laser light source, including:

a first electrical conduction pattern of a bottom electrical conduction pattern in the VCSEL laser light source is turned on at a first control current such that a first subset of a plurality of VCSEL units in the VCSEL laser light source are turned on.

In the driving method according to the present application, the method further includes: turning on a second electrical conduction pattern of the bottom electrical conduction pattern in the VCSEL laser light source at a second control current such that a second subset of the plurality of VCSEL cells in the VCSEL laser light source are turned on.

In the driving method according to the present application, the first control current and the second control current have different current magnitudes.

Further objects and advantages of the present application will become apparent from an understanding of the ensuing description and drawings.

These and other objects, features and advantages of the present application will become more fully apparent from the following detailed description, the accompanying drawings and the claims.

Drawings

These and/or other aspects and advantages of the present application will become more apparent and more readily appreciated from the following detailed description of the embodiments of the present application, taken in conjunction with the accompanying drawings of which:

fig. 1 is a top view of a VCSEL laser source that is divisionally conducting according to a preferred embodiment of the present application.

Fig. 2 is a top view of a modified embodiment of a sectionally-switchable VCSEL laser source in accordance with the preferred embodiment of the present application.

Fig. 3 is a cross-sectional view of a VCSEL laser source that is zonably conductive in accordance with a preferred embodiment of the present application.

Fig. 4 is an enlarged partial cross-sectional view of a VCSEL laser source that is zonably-conductive in accordance with a preferred embodiment of the present application.

Figure 5 is a cross-sectional view of an alternate embodiment of a sectionally-switchable VCSEL laser source in accordance with the preferred embodiment of the present application.

Fig. 6 is a schematic diagram of a manufacturing process of a VCSEL laser source capable of being turned on in a divisional manner according to a preferred embodiment of the present application.

Fig. 7 is a schematic diagram of a manufacturing process of a modified embodiment of a VCSEL laser source with split-conduction according to the preferred embodiment of the present application.

Fig. 8 is a flow chart of a driving method of the VCSEL laser source capable of being conducted in a divisional manner according to the preferred embodiment of the present application.

Detailed Description

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

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

While ordinal numbers such as "first," "second," etc., will be used to describe various components, those components are not limited herein. The term is used only to distinguish one element from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component, without departing from the teachings of the inventive concepts. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, numbers, steps, operations, components, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, elements, or groups thereof.

Summary of the application

As described above, in practical applications, VCSEL lasers are generally applied integrally in the form of VCSEL arrays, which represent optoelectronic devices capable of generating two or more laser beams. As the number of VCSEL lasers included in the VCSEL array increases, the power of the VCSEL array gradually increases, on one hand, the heat productivity of the high-power VCSEL array is large, and on the premise of not fully dissipating heat, the performance of a chip can be influenced; on the other hand, the electrode routing of an increasing number of VCSEL arrays becomes more complicated and difficult, especially for VCSEL lasers located in the middle region of the VCSEL array.

In order to solve the problem of heat dissipation, the conventional technical scheme is to change the heat sink configuration of the VCSEL laser or change the design of the bottom layer to change the heat-sensitive characteristics of the laser, but due to the characteristics specific to the VCSEL laser, the heat-sensitive characteristics are difficult to completely eliminate. That is, the existing technical solutions can only reduce the influence of temperature within a certain range.

Accordingly, the present inventors propose a technical direction of "zone lighting", i.e. by adjusting the wiring configuration in the VCSEL array to divide a relatively large number of VCSEL lasers into a plurality of light emitting areas that can be controlled individually or jointly, in such a way that, on the one hand, the heat dissipation problem of the VCSEL array due to high power is essentially solved, and, on the other hand, the application flexibility of the VCSEL array is also expanded.

Further, in the technical idea of determining how to perform the partitioned conducting wiring, the applicant of the present application proposes two wiring schemes: the multilayer wiring structure is disposed on the top side of the VCSEL array as its positive electrode, and the multilayer wiring structure is disposed on the top side of the VCSEL array as its negative electrode. Both technical concepts can achieve the technical purpose the application intends to achieve in principle.

However, in a specific alternative, the applicant of the present application considers that it is more preferable to dispose the multilayer wiring structure on the top side of the VCSEL array as its negative electrode. The reason is that, firstly, when the multilayer wiring structure is disposed on the top of the VCSEL array, the speed of transferring heat generated by the VCSEL laser to the outside is reduced, that is, on the one hand, the multilayer wiring structure is used to solve the problem of heat dissipation, but at the same time, the multilayer wiring structure disposed on the top side increases the difficulty of heat dissipation, which creates a pair of contradictions, resulting in a limited heat dissipation effect if the multilayer wiring structure is disposed on the top side as the positive electrode.

Secondly, when the multilayer wiring structure is disposed on top of the VCSEL array, it affects the light extraction of the VCSEL laser. Of course, a wiring structure with light-transmitting property can be adopted to solve the problem, but the wiring structure with light-transmitting property has higher cost and more complicated preparation process.

In summary, in the embodiment of the present application, an electrically conducting structure is disposed at the negative electrode, so that the VCSEL array can realize the zone lighting.

Based on the above research findings, the present application provides a laser light source with a partitionable VCSEL, comprising a VCSEL array including a plurality of VCSEL units electrically isolated from each other, wherein each VCSEL unit includes, from bottom to top, a substrate, a bottom reflector, an active region, a confinement layer having an opening, a top reflector, and an ohmic contact layer, an upper surface of the ohmic contact layer of each VCSEL unit includes a top electrical contact region of each VCSEL unit; a top electrical conduction pattern formed on top of said VCSEL array, wherein said top electrical conduction pattern is electrically connected to top electrical contact regions of all of said VCSEL units in said VCSEL array; and a bottom electrical conduction pattern formed at a bottom of the VCSEL array, wherein the bottom electrical conduction pattern comprises a first electrical conduction pattern and a second electrical conduction pattern, wherein the first electrical conduction pattern is electrically connected to a first subset of the plurality of VCSEL units and the second electrical conduction pattern is electrically connected to a second subset of the plurality of VCSEL units. In this way, the VCSEL is lighted in a partitioning mode through wiring at the bottom of the VCSEL array, and the preparation process and the performance of the VCSEL laser light source are optimized.

Exemplary laser light source and method of making the same

Referring to fig. 1 to 5 in the specification, a VCSEL laser light source 100 capable of being conduction in a partitioned manner according to an embodiment of the present application is illustrated, wherein the VCSEL laser light source 100 includes a VCSEL array 10, a top electrical conduction pattern 20 formed on a top of the VCSEL array, and a bottom electrical conduction pattern 30 formed on a bottom of the VCSEL array.

As shown in fig. 1 to 5, the VCSEL array 10 includes a plurality of VCSEL units 11 electrically isolated from each other, wherein each VCSEL unit 11 includes, from bottom to top, a substrate 111, a bottom reflector 112, an active region 113, a confinement layer 114 having an opening, a top reflector 115, and an ohmic contact layer 116, and an upper surface of the ohmic contact layer 116 of each VCSEL unit 11 includes a top electrical contact region 117 of each VCSEL unit. As shown in fig. 1 to 5, the top electrical conduction pattern 20 is electrically connected to the top electrical contact regions 117 of all the VCSEL units 11 in the VCSEL array 10. Further, the bottom electrical conduction pattern 30 includes a first electrical conduction pattern 31 and a second electrical conduction pattern 32, wherein the first electrical conduction pattern 31 is electrically connected to the first subset 12 of the plurality of VCSEL units 11, and the second electrical conduction pattern 32 is electrically connected to the second subset 13 of the plurality of VCSEL units 11. The laser light source 100 further includes a conductive adhesive layer 50 formed between the substrate 111 and the bottom electrically conductive pattern 30, the conductive adhesive layer 50 being used to fix the bottom electrically conductive pattern 30 to the substrate 111 and to electrically connect the substrate 111 to the bottom electrically conductive pattern 30.

Specifically, the VCSEL array further has a resonant cavity formed between the top reflector 115 and the bottom reflector 112, wherein the active region 113 and the active region 113 form a multiple quantum well structure, and the multiple quantum well structure provides optical gain when activated by current, and the confinement layer 114 can concentrate the current in the center of the VCSEL unit for generating higher gain in the quantum well structure.

The top electrically conductive pattern 20 and the bottom electrically conductive pattern 30 are used to conduct electrical current, the top electrically conductive pattern 20 is electrically connected to the top electrical contact region 117, and the bottom electrically conductive pattern 30 is electrically connected to the substrate 111 of the VCSEL unit 11. Current can be transferred to the top reflector 115 through the top electrically conductive pattern 20, the top electrical contact region 117, and the ohmic contact layer 116, and current is transferred to the bottom reflector 112 through the active region 113 after passing through the opening formed in the confinement layer 114 and the quantum well structure located in the resonant cavity, and finally to the bottom electrically conductive pattern 30 through the substrate 111. It is noted that the VCSEL array is a top emitting VCSEL array, wherein the top emitters 115 are capable of partially reflecting light, and the bottom emitters 112 allow light to reflect but not transmit, thereby allowing light to exit from one side of the top electrical conduction pattern 20 through the top emitters 115.

The first subset 12 is formed by at least one of the VCSEL units 11, and the at least one VCSEL unit 11 in the first subset 12 can be simultaneously turned on or off. Accordingly, the second subset 13 is formed by at least one VCSEL unit 11, and the at least one VCSEL unit in the second subset 12 can be simultaneously turned on or off.

Referring to fig. 1 of the specification, optionally, there are no VCSEL units 11 in common in the first subset 12 and the second subset 13 of the VCSEL array 10, that is, no VCSEL unit 11 in the VCSEL array 10 belongs to two or more subsets at the same time.

Referring to fig. 2 in the description, in other alternative embodiments, the first subset 12 of the VCSEL array 10 includes all VCSEL units 11 in the second subset 13. That is, all VCSEL units 11 located in the second subset 13 belong to both the second subset 13 and the first subset 12; whereas a part of the VCSEL units 11 in the second subset 12 belong to the second subset 13 and another part of the VCSEL units 11 do not belong to the second subset 13. That is, the first subset 12 comprises, in addition to all the VCSEL units 11 in the second subset 13, also some of the VCSEL units 11 that are not suitable for the second subset 13.

Further, the bottom electrical conduction pattern 30 further comprises a third conduction pattern 33, the third conduction pattern 33 being electrically connected to a third subset 14 of the plurality of VCSEL units 11 for conducting electrical current to the VCSEL units 11 belonging to the third subset 14. It should be noted that, in the preferred embodiment, the VCSEL units 11 of the VCSEL array 10 are divided into three regions, i.e. the first subset 12, the third subset 13 and the fourth subset 14, for example, and should not constitute a limitation of the present application, and accordingly, the bottom electrical conduction pattern 30 includes the first conduction pattern 31, the second conduction pattern 32 and the third conduction pattern 33, it is understood that the VCSEL units 11 of the VCSEL array 10 can be divided into more than three regions or subsets, and the number of specific regions or subsets into which the VCSEL units 11 of the VCSEL array 10 are divided should not constitute a limitation of the present application.

Further, the switchable VCSEL laser source 100 further includes an isolation mechanism 40 formed on the VCSEL array 10, and the isolation mechanism 40 is used to electrically isolate the VCSEL units 11 of the VCSEL array 10.

Referring to fig. 3 of the specification, optionally, the isolation mechanism 40 is a plurality of isolation grooves 41 formed between every two VCSEL units 11 of the VCSEL array 10, and each isolation groove 41 extends upward from the substrate 111 and penetrates through the substrate 111 and the bottom reflector 112 to reach the bottom of the top conductive pattern 20, so as to electrically isolate the VCSEL units 11 from each other through the isolation grooves 41.

Referring to fig. 5 of the specification, optionally, the isolation mechanism 40 includes a plurality of isolation mediums 42 formed between every two VCSEL units 11 of the VCSEL array 10 and doped on the substrate 111 and the bottom reflector 112 of each VCSEL unit 11, so as to electrically isolate the VCSEL units 11 from each other through the isolation mediums 42.

In the preparation process, the isolation medium 42 is selected from high-energy implantation doping of H, He, C, O and N, energy MeV level and dosage 1011-15. It is worth mentioning that in non-standard processes, for example, the substrate is processedThe thinning needs 10-20 um, the isolation medium 42 is selected from H, He, C, O, N and Si, the energy is hundreds of KeV level, and the dosage is 1011-17

Referring to fig. 6 of the specification, according to another aspect of the present application, the present application further provides a method 200 for manufacturing a VCSEL laser source, where the method 200 includes:

201: forming an epitaxial structure 15, wherein the epitaxial structure 15 sequentially comprises a substrate 111, a bottom reflector 112, an active region 113, a limiting layer 114, a top reflector 115 and an ohmic contact layer 116 from bottom to top;

202: forming a plurality of mesa structures 151 on the epitaxial structure 15 through an etching process, each of the mesa structures 151 including, from bottom to top, the active region 113, the confinement layer 114, the top reflector 115, and the ohmic contact layer 116, wherein the ohmic contact layer 116 includes a top electrical contact region 117 formed on an upper surface thereof;

203: oxidizing the confinement layer 114 of each of the mesa structures 151 by an oxidation process such that the confinement layer 114 has an opening with a specific aperture;

204: depositing a dielectric insulating layer 118 on the mesa structures 151, wherein the dielectric insulating layer 118 covers the upper surface of the substrate 111, the bottom regions of the mesa structures 151, and other regions of the ohmic contact layer 116 except for the top electrical contact regions 117;

205: forming a top electrical conduction pattern 20 on an upper surface of the ohmic contact layer 116, wherein the top electrical conduction pattern 20 is electrically connected to the top electrical contact regions 117 of all the mesa structures 151;

206: etching the substrate 111 and the bottom reflector 112 to form an isolation trench 41 between each two of the mesa structures 151, so as to form a plurality of VCSEL units 11 separated by the isolation trench 41, wherein the isolation trench 41 extends upward from the substrate 111 and penetrates through the substrate 111 and the bottom reflector 112, respectively, and reaches the bottom of the top electrically conductive pattern 20, and each VCSEL unit 11 includes, from bottom to top, the substrate 111, the bottom reflector 112, the active region 113, the confinement layer 114 having an opening, the top reflector 115, and the ohmic contact layer 116; and

207: a bottom electrical conduction pattern 30 electrically connected to the substrate 111 is formed on a lower surface of the substrate 111, wherein the bottom electrical conduction pattern 30 includes a first electrical conduction pattern 31 and a second electrical conduction pattern 32, wherein the first electrical conduction pattern 31 is electrically connected to a first subset 12 of the plurality of VCSEL units 11, and the second electrical conduction pattern 32 is electrically connected to a second subset 13 of the plurality of VCSEL units 11.

Further, in the step 207, forming a bottom electrically conductive pattern 30 electrically connected to the substrate 111 on a lower surface of the substrate 111, including:

2071: thinning the substrate 111;

2072: forming an electrical connection glue layer on the lower surface of the substrate 111; and

2073: the bottom electrically conductive pattern 30 is adhered and electrically connected to the electrical connection paste layer.

Note that, after the top electrical conduction pattern 20 is formed on the upper surface of the ohmic contact layer 116, the substrate 111 and the bottom reflector 112 are etched by an etching process to form the isolation trench 41 between each two of the mesa structures 151. Note that the substrate 111 and the bottom reflector 112 are etched by photolithography. The material of the top electrically conductive pattern 20 is metal, and since metal cannot be etched by photolithography, metal is not effective, the substrate 111 and the reflector 112 can be etched by photolithography to the bottom of the top electrically conductive pattern 20, that is, the isolation trench 41 penetrates through the substrate 111 and extends to the bottom of the top electrically conductive pattern 20, so as to effectively and electrically isolate the plurality of VCSEL units 11 in the VCSEL array 10.

Further, in the step 202, a plurality of mesa structures 151 are formed on the epitaxial structure 15 through a photolithography process.

In step 207, optionally, there are no VCSEL units 11 in common in the first subset 12 and the second subset 13. In further alternative embodiments, the first subset 12 can further include all the VCSEL units 11 in the second subset 13.

The bottom electrical conduction pattern 30 further includes a third electrical conduction pattern 33, and the third electrical conduction pattern 33 is electrically connected to a third subset 14 of the plurality of VCSEL units 11. Wherein the first electrically conductive pattern 31 of the bottom electrically conductive pattern 30 is for conducting an electrical current to the first subset 12 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the first subset 12; the second electrical conduction pattern 32 of the bottom electrical conduction pattern 30 is for conducting electrical current to the second subset 13 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the second subset 13; the third electrical conduction pattern 33 of the bottom electrical conduction pattern 30 is for conducting electrical current to the third subset 14 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the third subset 14. It will be understood by those skilled in the art that in alternative embodiments, the VCSEL units 11 of the VCSEL array 10 can be further divided into three or more subsets or regions, and accordingly, the bottom electrical conduction pattern 30 can be further divided into three or more conductive patterns arranged in the same layer or different layers to achieve the zonal illumination of the VCSEL units 11, and the number of the subsets or zones of the VCSEL units 11 of the VCSEL array 10 should not be construed as limiting the present application as long as the application purpose of the present application can be achieved.

In step 204, the dielectric insulating layer 118 is made of the non-metallic dielectric material, including but not limited to silicon dioxide (SiO2), silicon nitride (SiNx), silicon oxynitride (SiON), and the like.

Referring to fig. 7 of the specification, according to another aspect of the present application, the present application further provides a method 200a for manufacturing a VCSEL laser source, where the method 200a for manufacturing a VCSEL laser source includes:

201 a: forming an epitaxial structure 15, wherein the epitaxial structure 15 sequentially comprises a substrate 111, a bottom reflector 112, an active region 113, a limiting layer 114, a top reflector 115 and an ohmic contact layer 116 from bottom to top;

202 a: forming a plurality of mesa structures 151 on the epitaxial structure 15 through an etching process, each of the mesa structures 151 including, from bottom to top, the active region 113, the confinement layer 114, the top reflector 115, and the ohmic contact layer 116, wherein the ohmic contact layer 116 includes a top electrical contact region 117 formed on an upper surface thereof;

203 a: oxidizing the confinement layer 114 of each of the mesa structures 151 by an oxidation process such that the confinement layer 114 has an opening with a specific aperture;

204 a: implanting an isolation dielectric 42 between every two of the mesa structures 151, wherein the isolation dielectric 42 is doped to be formed on the substrate 111 and the bottom reflector 112 to form a plurality of VCSEL units 11 separated by the isolation dielectric 42, each VCSEL unit 11 comprising, from bottom to top, the substrate 111, the bottom reflector 112, the active region 113, the confinement layer 114 with an opening, the top reflector 115, and the ohmic contact layer 116;

205 a: depositing a dielectric insulating layer 118 on the mesa structures 151, wherein the dielectric insulating layer 118 covers the upper surface of the substrate 111, the bottom regions of the mesa structures 151, and other regions of the ohmic contact layer 116 except for the top electrical contact regions 117;

206 a: forming a top electrical conduction pattern 20 on an upper surface of the ohmic contact layer 116, wherein the top electrical conduction pattern 20 is electrically connected to the top electrical contact regions 117 of all of the mesa structures 151; and

207 a: a bottom electrical conduction pattern 30 electrically connected to the substrate 111 is formed on a lower surface of the substrate 111, wherein the bottom electrical conduction pattern 30 includes a first electrical conduction pattern 31 and a second electrical conduction pattern 32, wherein the first electrical conduction pattern 31 is electrically connected to a first subset 12 of the plurality of VCSEL units 11, and the second electrical conduction pattern 32 is electrically connected to a second subset 13 of the plurality of VCSEL units 11.

Further, in the step 207a, forming a bottom electrically conductive pattern 30 electrically connected to the substrate 111 on the lower surface of the substrate 111 includes:

2071 a: thinning the substrate 111;

2072 a: forming an electrical connection glue layer on the lower surface of the substrate 111; and

2073 a: the bottom electrically conductive pattern 30 is adhered and electrically connected to the electrical connection paste layer.

Specifically, between step 203a and step 205a, that is, between the steps of oxidizing the confinement layer of each of the mesa structures by an oxidation process and depositing a dielectric insulating layer on the mesa structures, the isolation medium 42 is implanted between each two of the mesa structures 151, wherein the isolation medium 42 can be doped on the substrate 111 and the bottom reflector 112 to separate the VCSEL array 10 into a plurality of VCSEL units 11 through the isolation medium 42. Alternatively, the sequence of step 203a and step 204a can be interchanged, that is, the isolation dielectric 42 is first implanted between every two of the mesa structures 151, and then the confinement layer 114 of each mesa structure 151 is oxidized by the oxidation process, and the sequence between step 203a and step 204a should not constitute a limitation of the present application.

Further, in the step 202a, a plurality of mesa structures 151 are formed on the epitaxial structure 15 through a photolithography process.

In step 205a, the dielectric insulating layer 118 is made of the non-metallic dielectric material, including but not limited to silicon dioxide (SiO2), silicon nitride (SiNx), silicon oxynitride (SiON), etc.

Optionally, after step 2071a, i.e. after thinning the substrate 111, the isolation medium 42 may be injected again between the VCSEL units 11, so as to further improve the electrical isolation effect between the VCSEL units 11. It will be appreciated that since the top electrical conduction pattern 20 has been formed on the upper surface of the ohmic contact layer 116, implantation of the isolation dielectric 42 again requires implantation on one side of the substrate 111.

In step 207a, optionally, there are no VCSEL units 11 in common in the first subset 12 and the second subset 13. In further alternative embodiments, the first subset 12 can further include all the VCSEL units 11 in the second subset 13.

The bottom electrical conduction pattern 30 further includes a third electrical conduction pattern 33, and the third electrical conduction pattern 33 is electrically connected to a third subset 14 of the plurality of VCSEL units 11. Wherein the first electrically conductive pattern 31 of the bottom electrically conductive pattern 30 is for conducting an electrical current to the first subset 12 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the first subset 12; the second electrical conduction pattern 32 of the bottom electrical conduction pattern 30 is for conducting electrical current to the second subset 13 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the second subset 13; the third electrical conduction pattern 33 of the bottom electrical conduction pattern 30 is for conducting electrical current to the third subset 14 of the plurality of VCSEL units 11 for lighting the VCSEL units 11 located within the third subset 14. It will be understood by those skilled in the art that in alternative embodiments, the VCSEL units 11 of the VCSEL array 10 can be further divided into three or more subsets or regions, and accordingly, the bottom electrically conductive pattern 30 can be further divided into three or more conductive patterns arranged in the same layer or different layers for realizing the zonal illumination of the VCSEL units 11, and the number of the subsets or zones of the VCSEL units 11 of the VCSEL array 10 should not be construed as limiting the present application as long as the application purpose of the present application can be achieved.

Referring to fig. 8 of the specification, according to another aspect of the present application, there is further provided a driving method 300 for a VCSEL laser source, for turning on the VCSEL laser source 100 capable of being turned on in a divisional manner, the driving method 300 includes:

301: the first electrically conducting pattern 31 of the bottom electrically conducting pattern 30 in the VCSEL laser light source is turned on with a first control current such that the first subset 12 of the plurality of VCSEL units 11 in the VCSEL laser light source 100 is turned on.

The driving method 300 further includes:

302: the second electrically conductive pattern 32 of the bottom electrically conductive pattern 30 of the VCSEL laser light source 100 is turned on with a second control current such that a second subset 13 of the plurality of VCSEL units 11 of the VCSEL laser light source 100 is turned on.

Wherein the first control current and the second control current have different current magnitudes, so that the first subset 12 and the second subset 13 of the plurality of VCSEL units 11 emit laser light with different brightness.

Further, the driving method 300 further includes:

303: the third electrically conductive pattern 33 of the bottom electrically conductive pattern 30 in the VCSEL laser light source is turned on with a third control current such that a third subset 14 of the plurality of VCSEL units in the VCSEL laser light source is turned on.

It will be appreciated by persons skilled in the art that the embodiments of the present application described above and illustrated in the drawings are given by way of example only and are not limiting of the present application. The objectives of the present application have been fully and effectively attained. The functional and structural principles of the present application have been shown and described in the examples, and any variations or modifications of the embodiments of the present application may be made without departing from the principles.

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