Semiconductor laser with ridge-side integrated PN junction temperature control layer and its fabrication method

Abstract

This application provides a semiconductor laser with a ridge-side integrated PN junction temperature control layer and its fabrication method, relating to the field of semiconductor laser technology. The semiconductor laser includes a substrate; an epitaxial structure formed on one side of the substrate along a first direction; the epitaxial structure having a first surface facing away from the substrate; a ridge waveguide layer formed on the first surface and extending along a second direction; a temperature control region formed on the first surface and located on one side of the ridge waveguide layer along a third direction; the temperature control region includes a P-type control layer and an N-type control layer, which form a PN junction. In this application embodiment, because the PN junction has high resistance and small footprint under static operation, it is possible to achieve efficient thermal tuning while reducing the process complexity of the thermal tuning scheme, improving structural reliability, and reducing the footprint, thereby meeting the industrial demands for high integration, low cost, and high reliability.

Description

Technical Field

[0001] This application relates to the field of semiconductor laser technology, and in particular to a semiconductor laser with a ridge-side integrated PN junction temperature control layer and its fabrication method. Background Technology

[0002] In optical communication and integrated optoelectronic systems, semiconductor lasers are core devices for achieving high-speed data transmission, wavelength division multiplexing (WDM), and optical interconnects. In high-density applications such as data centers, 5G base stations, optical modules, and photonic integrated circuits (PICs), lasers need to achieve precise wavelength tuning, narrow linewidth output, and stable transverse mode characteristics under low power consumption conditions.

[0003] For example, in wavelength division multiplexing (WDM) systems, the wavelength of the laser needs to be strictly matched with the optical fiber communication window (such as C-band or L-band) and needs to maintain wavelength stability during temperature fluctuations or aging. In optical interconnect scenarios, the transverse mode stability of the laser directly affects the signal transmission quality, while thermal tuning is used to compensate for wavelength shifts caused by changes in ambient temperature.

[0004] However, traditional thermal tuning solutions often face problems such as high process complexity, poor structural reliability, or large space occupation when pursuing efficient tuning, making it difficult to meet the industrial requirements of high integration, low cost, and high reliability. Summary of the Invention

[0005] This application provides a semiconductor laser with a ridge-side integrated PN junction temperature control layer and its fabrication method. The temperature control region is a PN junction composed of a P-type control layer and an N-type control layer. The PN junction has high resistance and small space occupation under static operation, which can reduce the process complexity of the thermal tuning scheme, improve the structural reliability and reduce the space occupation while achieving efficient thermal tuning, thereby meeting the industrial requirements of high integration, low cost and high reliability.

[0006] In a first aspect, embodiments of this application provide a semiconductor laser with a ridge-side integrated PN junction temperature control layer, comprising,

[0007] Substrate;

[0008] An epitaxial structure is formed on one side of the substrate along a first direction, the first direction being the thickness direction of the substrate; the epitaxial structure has a first surface facing away from the substrate;

[0009] A ridge waveguide layer is formed on the first surface and extends along a second direction perpendicular to the first direction;

[0010] A temperature control region is formed on the first surface and is located on one side of the ridge waveguide layer along a third direction, which is perpendicular to the first direction and the second direction. The temperature control region includes a P-type control layer and an N-type control layer, which form a PN junction.

[0011] In one possible implementation, a first electrode is disposed on the side of the substrate opposite to the epitaxial structure; a second electrode is disposed on the ridge waveguide layer; a third electrode is disposed on the P-type control layer; and a fourth electrode is disposed on the N-type control layer.

[0012] In one possible implementation, the temperature control zone is spaced apart from the ridge waveguide layer in the third direction.

[0013] In one possible implementation, the height dimension of the temperature control region along the first direction is less than or equal to the height dimension of the ridge waveguide layer along the first direction.

[0014] In one possible implementation, the P-type control layer and the N-type control layer are arranged sequentially along the first direction, the second direction, or the third direction.

[0015] In one possible implementation, the temperature control zone is divided into multiple sub-control zones with positional intervals along the second direction;

[0016] The P-type control layer is divided into multiple first combination segments with multiple position intervals along the second direction, and the N-type control layer is divided into multiple second combination segments with multiple position intervals along the second direction. The multiple first combination segments and the multiple second combination segments correspond one-to-one to form multiple sub-control regions.

[0017] The third electrode is divided into multiple third combined segments along the second direction, and the multiple third combined segments correspond one-to-one with the first combined segments in the multiple sub-control regions;

[0018] The fourth electrode is divided into multiple fourth combination segments along the second direction, and each of the multiple fourth combination segments corresponds one-to-one with the second combination segment in the multiple sub-control regions.

[0019] In one possible implementation, the temperature control zone is provided on at least one side of the ridge waveguide layer along the third direction.

[0020] In one possible implementation, there are two temperature control zones, and the two temperature control zones are located on opposite sides of the ridge waveguide layer along the third direction.

[0021] In one possible implementation, the two temperature control zones include a first zone and a second zone, the first zone having a first distance from the ridge waveguide layer along the third direction, and the second zone having a second distance from the ridge waveguide layer along the third direction, wherein the first distance is less than, equal to, or greater than the second distance.

[0022] Secondly, embodiments of this application provide a method for fabricating a semiconductor laser, including,

[0023] Provide substrate;

[0024] An epitaxial structure is formed on one side of the substrate along a first direction, the first direction being the thickness direction of the substrate; the epitaxial structure has a first surface facing away from the substrate;

[0025] A ridge waveguide layer is formed on the first surface, and the ridge waveguide layer extends along a second direction, which is perpendicular to the first direction;

[0026] A temperature control region is formed on the first surface, and the temperature control region is located on one side of the ridge waveguide layer along a third direction, which is perpendicular to the first direction and the second direction; the temperature control region includes a P-type control layer and an N-type control layer, and the P-type control layer and the N-type control layer form a PN junction.

[0027] The semiconductor laser with a ridge-side integrated PN junction temperature control layer and its fabrication method provided in this application, when the semiconductor laser is in operation—that is, when a voltage is applied to the side of the ridge waveguide layer away from the epitaxial structure and the side of the substrate away from the epitaxial structure to generate laser light in the quantum well active layer—increases the temperature of the temperature control region by applying voltage to the P-type control layer and the N-type control layer. This temperature control region then heats the epitaxial structure, achieving the effect of regulating the temperature of the epitaxial structure. The wavelength of the laser light generated in the quantum well active layer changes due to the temperature of the epitaxial structure, thus enabling the temperature control region to regulate the wavelength of the laser light. Furthermore, while regulating the wavelength of the laser light, the temperature control region also forms an electric field around it, which restricts the lateral diffusion of charge carriers in the epitaxial structure, allowing for more concentrated injection of charge carriers into the quantum well active layer.

[0028] In this embodiment, the ridge waveguide layer and the temperature control region are jointly disposed on the first surface of the epitaxial structure, and the temperature control region is located on one side of the ridge waveguide layer. Since the temperature control region is a PN junction composed of a P-type control layer and an N-type control layer, the PN junction has a large resistance and occupies a small space under static operation. Thus, while achieving efficient thermal tuning, it can reduce the process complexity of the thermal tuning scheme, improve the structural reliability, and reduce the space occupied, thereby meeting the industrial requirements of high integration, low cost, and high reliability. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This is a cross-sectional view provided for some embodiments of this application after forming an epitaxial structure on a substrate;

[0031] Figure 2 A cross-sectional view of the epitaxial structure after forming a ridge waveguide layer and a P-type control layer on the first surface of the epitaxial structure, provided for some embodiments of this application;

[0032] Figure 3 A cross-sectional view of the epitaxial structure after a ridge waveguide layer and a temperature control region have been formed on the first surface of the epitaxial structure, as provided in some embodiments of this application;

[0033] Figure 4 A first cross-sectional view of a semiconductor laser provided in some embodiments of this application;

[0034] Figure 5 A first top view of a semiconductor laser provided in some embodiments of this application;

[0035] Figure 6 A second cross-sectional view of a semiconductor laser provided in some embodiments of this application;

[0036] Figure 7 A second top view of a semiconductor laser provided in some embodiments of this application;

[0037] Figure 8 A third top view of a semiconductor laser provided in some embodiments of this application;

[0038] Figure 9 A flowchart illustrating a method for fabricating a semiconductor laser as provided in some embodiments of this application.

[0039] Explanation of reference numerals in the attached figures:

[0040] 100, Substrate; 110, First Electrode;

[0041] 200. Epitaxial structure; 201. First surface; 210. Electron supply layer; 220. N-type cladding; 230. N-type waveguide layer; 240. Quantum well active layer; 250. P-type waveguide layer; 260. Electron blocking layer; 270. P-type cladding; 280. Hole supply layer;

[0042] 300. Ridge waveguide layer; 310. Second electrode;

[0043] 400, Temperature control zone; 401, P-type control layer; 401a, First combined section; 402, N-type control layer; 402a, Second combined section; 403, Third electrode; 403a, Third combined section; 404, Fourth electrode; 404a, Fourth combined section; 410, Sub-control zone; 420, First zone; 430, Second zone.

[0044] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0045] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0046] In optical communication and integrated optoelectronic systems, semiconductor lasers are core devices for achieving high-speed data transmission, wavelength division multiplexing (WDM), and optical interconnects. In high-density applications such as data centers, 5G base stations, optical modules, and photonic integrated circuits (PICs), lasers need to achieve precise wavelength tuning, narrow linewidth output, and stable transverse mode characteristics under low power consumption conditions.

[0047] For example, in wavelength division multiplexing (WDM) systems, the wavelength of the laser needs to be strictly matched with the optical fiber communication window (such as C-band or L-band) and needs to maintain wavelength stability during temperature fluctuations or aging. In optical interconnect scenarios, the transverse mode stability of the laser directly affects the signal transmission quality, while thermal tuning is used to compensate for wavelength shifts caused by changes in ambient temperature.

[0048] However, traditional thermal tuning solutions often face problems such as high process complexity, poor structural reliability, or large space occupation when pursuing efficient tuning, making it difficult to meet the industrial requirements of high integration, low cost, and high reliability.

[0049] This application provides a semiconductor laser with a ridge-side integrated PN junction temperature control layer and its fabrication method. When the semiconductor laser is in operation, that is, when a voltage is applied to the side of the ridge waveguide layer away from the epitaxial structure and the side of the substrate away from the epitaxial structure to generate laser light in the quantum well active layer, the temperature of the temperature control region is increased by applying voltage to the P-type control layer and the N-type control layer. This temperature control region can then heat the epitaxial structure, thereby achieving the effect of regulating the temperature of the epitaxial structure. The wavelength of the laser light generated in the quantum well active layer changes due to the temperature of the epitaxial structure, thus enabling the temperature control region to regulate the wavelength of the laser light. Furthermore, while regulating the wavelength of the laser light, the temperature control region also forms an electric field around it, which restricts the lateral diffusion of charge carriers in the epitaxial structure, allowing the charge carriers to be injected more concentratedly into the quantum well active layer.

[0050] In this embodiment, the ridge waveguide layer and the temperature control region are jointly disposed on the first surface of the epitaxial structure, and the temperature control region is located on one side of the ridge waveguide layer. Since the temperature control region is a PN junction composed of a P-type control layer and an N-type control layer, the PN junction has a large resistance and occupies a small space under static operation. Thus, while achieving efficient thermal tuning, it can reduce the process complexity of the thermal tuning scheme, improve the structural reliability, and reduce the space occupied, thereby meeting the industrial requirements of high integration, low cost, and high reliability.

[0051] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0052] In a first aspect, this application provides a semiconductor laser with a ridge-side integrated PN junction temperature control layer, see [link to relevant documentation]. Figure 4 and Figure 5 As shown, the semiconductor laser includes a substrate 100, on which an epitaxial structure 200 is formed, where the first direction X is the thickness direction of the substrate 100. The epitaxial structure 200 has a first surface 201 facing away from the substrate 100 along the first direction X. A ridge waveguide layer 300 is disposed on the first surface 201 of the epitaxial structure 200, and the ridge waveguide layer 300 extends along a second direction Y on the first surface 201, where the second direction Y is perpendicular to the first direction X.

[0053] For example, when a voltage is applied to the side of the ridge waveguide layer 300 away from the epitaxial structure 200 and the side of the substrate 100 away from the epitaxial structure 200, current flows from the ridge waveguide layer 300 through the epitaxial structure 200 and the substrate 100 in sequence. During this process, charge carriers accumulate in the epitaxial structure 200 to generate laser light.

[0054] In another exemplary embodiment, the epitaxial structure 200 includes an electron supply layer 210, an N-type cladding layer 220, an N-type waveguide layer 230, a quantum well active layer 240, a P-type waveguide layer 250, an electron blocking layer 260, a P-type cladding layer 270, and a hole supply layer 280. The electron supply layer 210 is formed on one side of the substrate 100 along the first direction X, the N-type cladding layer 220 is formed on the side of the electron supply layer 210 away from the substrate 100, the N-type waveguide layer 230 is formed on the side of the N-type cladding layer 220 away from the substrate 100, the quantum well active layer 240 is formed on the side of the N-type waveguide layer 230 away from the substrate 100, the P-type waveguide layer 250 is formed on the side of the quantum well active layer 240 away from the substrate 100, the electron blocking layer 260 is formed on the side of the P-type waveguide layer 250 away from the substrate 100, the P-type cladding layer 270 is formed on the side of the electron blocking layer 260 away from the substrate 100, and the hole supply layer 280 is formed on the side of the P-type cladding layer 270 away from the substrate 100.

[0055] It is understandable that the hole supply layer 280 in the epitaxial structure 200 is furthest from the substrate 100 in the first direction X. Therefore, the first surface 201 of the epitaxial structure 200 is the surface of the hole supply layer 280 away from the substrate 100. That is to say, the ridge waveguide layer 300 is formed on the surface of the hole supply layer 280 away from the substrate 100.

[0056] When a voltage is applied to the side of the ridge waveguide layer 300 facing away from the epitaxial structure 200 and the side of the substrate 100 facing away from the epitaxial structure 200, current flows from the ridge waveguide layer 300 sequentially through the hole supply layer 280, the P-type cladding layer 270, the electron blocking layer 260, the P-type waveguide layer 250, the quantum well active layer 240, the N-type waveguide layer 230, the N-type cladding layer 220, the electron supply layer 210, and the substrate 100. During this process, holes in the charge carriers converge from the hole supply layer 280 sequentially through the P-type cladding layer 270, the electron blocking layer 260, and the P-type waveguide layer 250 toward the quantum well active layer 240, and electrons in the charge carriers converge from the electron supply layer 210 sequentially through the N-type cladding layer 220 and the N-type waveguide layer 230 toward the quantum well active layer 240, thereby generating laser light in the quantum well active layer 240.

[0057] See Figure 4 and Figure 5As shown, the semiconductor laser of this embodiment further includes a temperature control region 400, which is formed on the first surface 201. That is, the temperature control region 400 is formed on the surface of the hole supply layer 280 facing away from the substrate 100. Further, the temperature control region 400 is located on the side of the ridge waveguide layer 300 along the third direction Z, where the third direction Z is perpendicular to the first direction X and the second direction Y.

[0058] The temperature control region 400 includes a P-type control layer 401 and an N-type control layer 402. The P-type control layer 401 and the N-type control layer 402 together form a PN junction, that is, a PN junction is formed on the first surface 201, and this PN junction can serve as the temperature control region 400.

[0059] It is understandable that when voltages are applied to the P-type control layer 401 and the N-type control layer 402 respectively, an electric field can be formed around the temperature control region 400, and the overall temperature of the temperature control region 400 will also rise due to the large resistance of the PN junction under static operation.

[0060] When the semiconductor laser of this embodiment is in operation, that is, when a voltage is applied to the side of the ridge waveguide layer 300 away from the epitaxial structure 200 and the side of the substrate 100 away from the epitaxial structure 200 to generate laser light in the quantum well active layer 240, the temperature of the temperature control region 400 is increased by applying voltage to the P-type control layer 401 and the N-type control layer 402. As a result, the temperature control region 400 can heat the epitaxial structure 200, so that the temperature control region 400 can achieve the effect of regulating the temperature of the epitaxial structure 200. The wavelength of the laser light generated in the quantum well active layer 240 changes due to the temperature of the epitaxial structure 200, so that the temperature control region 400 can achieve the effect of regulating the wavelength of the laser light.

[0061] Furthermore, while the temperature control region 400 can adjust the wavelength of the laser, an electric field is formed around the temperature control region 400, which restricts the lateral diffusion of charge carriers in the epitaxial structure 200 under the action of the electric field, thereby enabling the charge carriers to be injected into the quantum well active layer 240 more concentratedly.

[0062] In the embodiments of this application, see Figure 4 and Figure 5As shown, by jointly setting the ridge waveguide layer 300 and the temperature control region 400 on the first surface 201 of the epitaxial structure 200, and with the temperature control region 400 located on one side of the ridge waveguide layer 300, since the temperature control region 400 is a PN junction composed of a P-type control layer 401 and an N-type control layer 402, the PN junction has a large resistance and occupies a small space under static operation. Thus, while achieving efficient thermal tuning, it is possible to reduce the process complexity of the thermal tuning scheme, improve structural reliability, and reduce the space occupied, thereby meeting the industrial requirements of high integration, low cost, and high reliability.

[0063] In some embodiments of this application, see Figure 4 and Figure 5 As shown, a first electrode 110 is disposed on the side of the substrate 100 away from the epitaxial structure 200, and a second electrode 310 is disposed on the side of the ridge waveguide layer 300 away from the epitaxial structure 200.

[0064] When voltages are applied to the substrate 100 and the ridge waveguide layer 300 through the first electrode 110 and the second electrode 310 respectively, current flows from the ridge waveguide layer 300 through the epitaxial structure 200 and the substrate 100 in sequence. During this process, charge carriers accumulate in the epitaxial structure 200 to generate laser light.

[0065] Furthermore, in the embodiments of this application, see... Figure 4 and Figure 5 As shown, a third electrode 403 is provided on the P-type control layer 401, and a fourth electrode 404 is provided on the N-type control layer 402.

[0066] Voltages can be applied to the P-type control layer 401 and the N-type control layer 402 through the third electrode 403 and the fourth electrode 404, respectively, thereby increasing the temperature of the temperature control region 400 and forming an electric field around the temperature control region 400. This allows the temperature control region 400 to influence the temperature of the epitaxial structure 200, thereby adjusting the wavelength of the laser, and to restrict the lateral diffusion of charge carriers in the epitaxial structure 200 through the electric field, thereby improving the injection efficiency of charge carriers into the quantum well active layer 240.

[0067] In the embodiments of this application, see Figure 4 and Figure 5As shown, the first electrode 110, the second electrode 310, the third electrode 403, and the fourth electrode 404 are independent of each other. That is, applying voltage to the first electrode 110 and the second electrode 310 to generate laser light is an independent working mechanism, and applying voltage to the third electrode 403 and the fourth electrode 404 to generate heat and form an electric field in the temperature control zone 400 is an independent working mechanism. Without affecting laser generation, the voltage applied to the third electrode 403 and the fourth electrode 404 can be flexibly changed, thereby flexibly adjusting the heat generation and electric field strength of the temperature control zone 400, and thus achieving the effect of flexibly controlling the laser wavelength.

[0068] In some embodiments of this application, see Figure 4 and Figure 5 As shown, the temperature control region 400 is spaced apart from the ridge waveguide layer 300 in the third direction Z, so that the temperature control region 400 and the ridge waveguide layer 300 can be structurally decoupled.

[0069] When a voltage is applied to the first electrode 110 and the second electrode 310, current flows in the ridge waveguide layer 300 toward the substrate 100. During this process, the current also diffuses in the ridge waveguide layer 300 in a direction perpendicular to the first direction X. Since the temperature control region 400 and the ridge waveguide layer 300 are spaced apart in this embodiment, the current in the ridge waveguide layer 300 can be prevented from diffusing into the temperature control region 400. On the one hand, this avoids affecting the heat generation and electric field of the temperature control region 400, and on the other hand, it avoids the current diffusion leading to a decrease in the injection efficiency of the carrier-to-quantum-well active layer 240.

[0070] In some embodiments of this application, the height dimension of the temperature control region 400 along the first direction X is smaller than the height dimension of the ridge waveguide layer 300 along the first direction X, or the height dimension of the temperature control region 400 along the first direction X is equal to the height dimension of the ridge waveguide layer 300 along the first direction X, or the height dimension of the temperature control region 400 along the first direction X is higher than the height dimension of the ridge waveguide layer 300 along the first direction X. No particular limitation is made in this regard.

[0071] Furthermore, in order to reduce the space occupied by the temperature tuning region in the entire semiconductor laser and meet the industrial requirements of high integration, preferably, see [reference needed]. Figure 4 As shown, the height dimension of the temperature control region 400 along the first direction X is less than the height dimension of the ridge waveguide layer 300 along the first direction X, or the height dimension of the temperature control region 400 along the first direction X is equal to the height dimension of the ridge waveguide layer 300 along the first direction X.

[0072] In some embodiments of this application, see Figure 6As shown, the P-type control layer 401 and the N-type control layer 402 are arranged sequentially along the first direction X, or, see [link to relevant documentation]. Figure 7 As shown, the P-type control layer 401 and the N-type control layer 402 are arranged sequentially along the second direction Y, or, see [link to relevant documentation]. Figure 4 and Figure 5 As shown, the P-type control layer 401 and the N-type control layer 402 are arranged sequentially along the third direction Z. There are no special limitations on this, as long as the temperature control region 400 can generate heat and achieve the effect of adjusting the wavelength of the laser.

[0073] In some embodiments of this application, see Figure 8 As shown, the temperature control zone 400 is divided into multiple sub-control zones 410 along the second direction Y, and the multiple sub-control zones 410 are arranged sequentially at intervals along the second direction Y.

[0074] For example, see Figure 8 As shown, the P-type control layer 401 is divided into multiple first combination segments 401a along the second direction Y, and the multiple first combination segments 401a are arranged sequentially at intervals along the second direction Y. The N-type control layer 402 is divided into multiple second combination segments 402a along the second direction Y, and the multiple second combination segments 402a are arranged sequentially at intervals along the second direction Y. The multiple first combination segments 401a and the multiple second combination segments 402a correspond one-to-one to form multiple sub-control regions 410, and the multiple sub-control regions 410 are arranged sequentially at intervals along the second direction Y.

[0075] Since each sub-control region 410 includes a first combination segment 401a and a second combination segment 402a, and the first combination segment 401a and the second combination segment 402a form a PN junction, each sub-control region 410 can generate heat and form an electric field under the applied voltage, thereby achieving the effect of adjusting the wavelength of the laser generated by the semiconductor laser.

[0076] It is worth mentioning that, since multiple sub-control regions 410 are arranged sequentially at intervals in the second direction Y, each sub-control region 410 corresponds to a part of the epitaxial structure 200, thereby enabling the sub-control region 410 to heat a specific area of ​​the epitaxial structure 200, and the sub-control region 410 to limit the lateral diffusion of current in the specific area of ​​the epitaxial structure 200 by forming an electric field.

[0077] Furthermore, in the embodiments of this application, see... Figure 8As shown, the third electrode 403 is divided into multiple third combination segments 403a along the second direction Y, and each of the multiple third combination segments 403a corresponds one-to-one with the first combination segment 401a in the multiple sub-control regions 410. The fourth electrode 404 is divided into multiple fourth combination segments 404a along the second direction Y, and each of the multiple fourth combination segments 404a corresponds one-to-one with the second combination segment 402a in the multiple sub-control regions 410. That is, in each sub-control region 410, a third combination segment 403a is provided on the first combination segment 401a, and a fourth combination segment 404a is provided on the second combination segment 402a.

[0078] For example, see Figure 8 As shown, when a voltage is applied to the third combination segment 403a and the fourth combination segment 404a in any sub-control region 410, the corresponding sub-control region 410 will generate heat and form an electric field, thereby enabling the adjustment of the wavelength of the laser generated by the semiconductor laser and limiting the lateral diffusion of current in the epitaxial structure 200.

[0079] In some embodiments of this application, the ridge waveguide layer 300 is provided with the aforementioned temperature control region 400 on at least one side along the third direction Z.

[0080] For example, the ridge waveguide layer 300 is provided with a temperature control zone 400 on either side of the third direction Z.

[0081] Another example is seen in [reference 1]. Figure 4 and Figure 5 As shown, temperature control regions 400 are provided on both sides of the ridge waveguide layer 300 along the third direction Z, which makes the tuning of the wavelength of the laser generated by the semiconductor laser more flexible.

[0082] In some embodiments of this application, see Figure 4 As shown, two temperature control areas 400 are provided on the first surface 201, and the two temperature control areas 400 are located on both sides of the ridge waveguide layer 300 along the third direction Z. Specifically, the two temperature control areas 400 are the first area 420 and the second area 430.

[0083] For example, voltages are applied to the first region 420 and the second region 430 respectively, and the voltage applied to the first region 420 may be greater than the voltage applied to the second region 430, so that the first region 420 and the second region 430 form an asymmetric thermal tuning and electric field.

[0084] Another example is that a voltage is applied to the first region 420 and no voltage is applied to the second region 430, such that a thermally tuned electric field is formed on one side of the ridge waveguide layer 300.

[0085] As another example, voltages are applied to the first region 420 and the second region 430 respectively, and the voltage applied to the first region 420 is equal to the voltage applied to the second region 430, so that the first region 420 and the second region 430 form a symmetrical thermal tuning and electric field.

[0086] As another example, voltages are applied to the first region 420 and the second region 430 respectively, and the voltage applied to the first region 420 is less than the voltage applied to the second region 430, so that the first region 420 and the second region 430 form an asymmetric thermal tuning and electric field.

[0087] As another example, no voltage is applied to the first region 420, but a voltage is applied to the second region 430, such that a thermally tuned electric field is formed on one side of the ridge waveguide layer 300.

[0088] The embodiments of this application can improve the flexibility of adjusting the wavelength of the laser generated by the semiconductor laser by adjusting the voltage applied to the first region 420 and by adjusting the voltage applied to the second region 430.

[0089] In some embodiments of this application, see Figure 4 As shown, the first region 420 has a first distance from the ridge waveguide layer 300 along the third direction Z, and the second region 430 has a second distance from the ridge waveguide layer 300 along the third direction Z. The first distance is less than the second distance, or the first distance is equal to the second distance, or the first distance is greater than the second distance.

[0090] For example, when the first distance is less than the second distance, when the same voltage is applied to the first region 420 and the second region 430, the first region 420 and the second region 430 form an asymmetric thermal tuning and electric field on both sides of the ridge waveguide layer 300, with the ridge waveguide layer 300 as the boundary.

[0091] As another example, when the first distance is equal to the second distance, when the same voltage is applied to the first region 420 and the second region 430, the first region 420 and the second region 430 form symmetrical thermal tuning and electric fields on both sides of the ridge waveguide layer 300, with the ridge waveguide layer 300 as the boundary.

[0092] As another example, when the first distance is greater than the second distance, when the same voltage is applied to the first region 420 and the second region 430, the first region 420 and the second region 430 form asymmetric thermal tuning and voltage on both sides of the ridge waveguide layer 300, with the ridge waveguide layer 300 as the boundary.

[0093] The embodiments of this application can improve the flexibility of adjusting the wavelength of the laser generated by the semiconductor laser by adjusting the size of the first distance and the size of the second distance.

[0094] In some embodiments of this application, the substrate 100 may be made of GaN or GaAs, and there is no particular limitation on the material.

[0095] Furthermore, the thickness of the substrate 100 in the first direction X can be 200 nm-3 μm.

[0096] In some embodiments of this application, the electron supply layer 210 may be made of AlInGaN or AlGaAs, and there is no particular limitation on the material.

[0097] Furthermore, the thickness of the electron supply layer 210 in the first direction X can be 0.3 μm-1 μm.

[0098] In some embodiments of this application, the material of the N-type cladding 220 can be AlInGaN or AlGaAs, and there is no particular limitation thereto.

[0099] Furthermore, the thickness of the N-type cladding 220 in the first direction X can be 0.1 μm-3 μm.

[0100] In some embodiments of this application, the material of the N-type waveguide layer 230 can be AlInGaN or AlGaAs, and there is no particular limitation thereto.

[0101] Furthermore, the thickness of the N-type waveguide layer 230 in the first direction X can be 0.1 μm–0.5 μm.

[0102] In some embodiments of this application, the active quantum well layer 240 may be made of alternating AlInGaN well layers and AlInGaN barrier layers, or the active quantum well layer 240 may be made of alternating InGaAs well layers and AlGaAs barrier layers, and there is no particular limitation on the material.

[0103] Furthermore, the thickness of the quantum well active layer 240 in the first direction X can be 0.1 μm.

[0104] In some embodiments of this application, the material of the P-type waveguide layer 250 can be AlInGaN or AlGaAs, and there is no particular limitation thereto.

[0105] Furthermore, the thickness of the P-type waveguide layer 250 in the first direction X can be 0.1μm-0.5μm.

[0106] In some embodiments of this application, the electron blocking layer 260 may be made of AlInGaN or AlGaAs, and there is no particular limitation on the material.

[0107] Furthermore, the thickness of the electron blocking layer 260 in the first direction X can be 0.1 μm-3 μm.

[0108] In some embodiments of this application, the material of the P-type cladding 270 can be AlInGaN or AlGaAs, and there is no particular limitation thereto.

[0109] Furthermore, the thickness of the P-type cladding 270 in the first direction X can be 0.1 μm-3 μm.

[0110] In some embodiments of this application, the hole supply layer 280 may be made of AlInGaN or AlGaAs, and there is no particular limitation on the material.

[0111] Furthermore, the thickness of the hole supply layer 280 in the first direction X can be 0.3 μm-1 μm.

[0112] In some embodiments of this application, the material of the N-type control layer 402 can be the N-type material ZnO, and there is no particular limitation thereto.

[0113] Furthermore, the thickness of the N-type control layer 402 in the first direction X can be 0.2μm-0.3μm.

[0114] In some embodiments of this application, the ridge waveguide layer 300 may be made of heavily doped P-type material. + -AlInGaN or AlGaAs, with no particular limitation.

[0115] Furthermore, the thickness of the ridge waveguide layer 300 in the first direction X is 0.3μm-0.5μm.

[0116] In some embodiments of this application, the p-type control layer 401 can be made of heavily doped p-type material. + -AlInGaN or AlGaAs, with no particular limitation.

[0117] Furthermore, the thickness of the P-type control layer 401 in the first direction X can be 0.2μm-0.3μm.

[0118] Secondly, this application provides a method for fabricating a semiconductor laser, which is used to fabricate the aforementioned semiconductor laser with a ridge-side integrated PN junction temperature control layer. Therefore, it can possess the corresponding technical effects and advantages described above.

[0119] See Figure 9 As shown, the method for fabricating a semiconductor laser according to an embodiment of this application includes the following steps:

[0120] Step s100: Provide a substrate.

[0121] In this step, the substrate 100 is placed in the growth chamber of the MOCVD equipment.

[0122] Step s200: An epitaxial structure is formed on one side of the substrate along a first direction, the first direction being the thickness direction of the substrate; the epitaxial structure has a first surface facing away from the substrate.

[0123] In this step, for example, see Figure 1 As shown, the epitaxial structure 200 includes an electron supply layer 210, an N-type cladding layer 220, an N-type waveguide layer 230, a quantum well active layer 240, a P-type waveguide layer 250, an electron blocking layer 260, a P-type cladding layer 270, and a hole supply layer 280. The electron supply layer 210, N-type cladding layer 220, N-type waveguide layer 230, quantum well active layer 240, P-type waveguide layer 250, electron blocking layer 260, P-type cladding layer 270, and hole supply layer 280 are sequentially grown on one side of the substrate 100 along the first direction X. The surface of the hole supply layer 280 facing away from the substrate 100 serves as the first surface 201 of the epitaxial structure 200.

[0124] Step s300: A ridge waveguide layer is formed on the first surface, and the ridge waveguide layer extends along a second direction, which is perpendicular to the first direction.

[0125] In this step, see Figure 2 As shown, a ridge waveguide layer 300 is fabricated on the first surface 201 of the epitaxial structure 200 by processes such as epitaxial growth, photolithography and dry etching, and the ridge waveguide layer 300 extends along the second direction Y.

[0126] For example, see Figure 2 As shown, the ridge waveguide layer 300 is formed on the surface of the hole supply layer 280 away from the substrate 100.

[0127] Step s400: A temperature control region is formed on the first surface, and the temperature control region is located on one side of the ridge waveguide layer along the third direction, which is perpendicular to the first direction and the second direction; the temperature control region includes a P-type control layer and an N-type control layer, which form a PN junction.

[0128] In this step, see Figure 2 As shown, while forming a ridge waveguide layer 300 on the first surface 201 of the epitaxial structure 200, a P-type control layer 401 is simultaneously prepared on the first surface 201 through epitaxial growth, photolithography and dry etching processes, and the P-type control layer 401 is located on the side of the ridge waveguide layer 300 along the third direction Z.

[0129] For example, see Figure 2 As shown, a P-type control layer 401 is formed on the surface of the hole supply layer 280 facing away from the substrate 100.

[0130] Furthermore, after forming the ridge waveguide layer 300 and the P-type control layer 401, see [link to documentation]. Figure 3As shown, an N-type control layer 402 is fabricated on the first surface 201 of the epitaxial structure 200 by processes such as growth, photolithography and dry etching. The N-type control layer 402 is located on the Z-side of the ridge waveguide layer 300 along the third direction, so that the N-type control layer 402 and the P-type control layer 401 form a PN junction.

[0131] For example, see Figure 3 As shown, an N-type control layer 402 is formed on the surface of the hole supply layer 280 facing away from the substrate 100.

[0132] In some embodiments of this application, after step s400, see [link to relevant documentation]. Figure 3 and Figure 4 As shown, the method for fabricating a semiconductor laser further includes the following steps: fabricating a first electrode 110, a second electrode 310, a third electrode 403, and a fourth electrode 404 using photolithography and e-beam evaporation processes, wherein the first electrode 110 is formed on the side of the substrate 100 away from the epitaxial structure 200, the second electrode 310 is formed on the ridge waveguide layer 300, the third electrode 403 is formed on the P-type control layer 401, and the fourth electrode 404 is formed on the N-type control layer 402.

[0133] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A semiconductor laser with a ridge-integrated PN junction temperature control layer, characterized by: include, Substrate (100); An epitaxial structure (200) is formed on one side of the substrate (100) along a first direction, the first direction being the thickness direction of the substrate (100); the epitaxial structure (200) has a first surface (201) facing away from the substrate (100). A ridge waveguide layer (300) is formed on the first surface (201) and extends along a second direction perpendicular to the first direction; A temperature control region (400) is formed on the first surface (201) and is located on one side of the ridge waveguide layer (300) along a third direction, which is perpendicular to the first direction and the second direction. The temperature control region (400) includes a P-type control layer (401) and an N-type control layer (402), which form a PN junction. When a voltage is applied, the temperature control region (400) can generate an electric field in the epitaxial structure (200), which is used to limit the lateral diffusion of charge carriers in the epitaxial structure (200). A first electrode (110) is disposed on the side of the substrate (100) away from the epitaxial structure (200); a second electrode (310) is disposed on the ridge waveguide layer (300); a third electrode (403) is disposed on the P-type control layer (401); and a fourth electrode (404) is disposed on the N-type control layer (402). The temperature control zone (400) is spaced apart from the ridge waveguide layer (300) in the third direction.

2. The semiconductor laser of claim 1, wherein: The height dimension of the temperature control zone (400) along the first direction is less than or equal to the height dimension of the ridge waveguide layer (300) along the first direction.

3. The semiconductor laser of claim 1, wherein: The P-type control layer (401) and the N-type control layer (402) are arranged sequentially along the first direction, the second direction, or the third direction.

4. The semiconductor laser according to claim 1, characterized in that: The temperature control zone (400) is divided into multiple sub-control zones (410) with positional intervals along the second direction. The P-type control layer (401) is divided into multiple position-spaced first combination segments (401a) along the second direction, and the N-type control layer (402) is divided into multiple position-spaced second combination segments (402a) along the second direction. The multiple first combination segments (401a) and the multiple second combination segments (402a) correspond one-to-one to form multiple sub-control regions (410). The third electrode (403) is divided into multiple third combination segments (403a) along the second direction, and the multiple third combination segments (403a) correspond one-to-one with the first combination segment (401a) in the multiple sub-control regions (410); The fourth electrode (404) is divided into multiple fourth combination segments (404a) along the second direction, and the multiple fourth combination segments (404a) correspond one-to-one with the second combination segment (402a) in the multiple sub-control regions (410).

5. The semiconductor laser according to any one of claims 1-4, characterized in that: The temperature control region (400) is provided on at least one side along the third direction of the ridge waveguide layer (300).

6. The semiconductor laser according to claim 5, characterized in that: The number of temperature control zones (400) is two, and the two temperature control zones (400) are respectively located on both sides of the ridge waveguide layer (300) along the third direction.

7. The semiconductor laser according to claim 6, characterized in that: The two temperature control zones (400) include a first zone (420) and a second zone (430), wherein the first zone (420) has a first distance from the ridge waveguide layer (300) along the third direction, and the second zone (430) has a second distance from the ridge waveguide layer (300) along the third direction, wherein the first distance is less than, equal to or greater than the second distance.

8. A method for fabricating a semiconductor laser, characterized in that: The preparation method is used to prepare a semiconductor laser as described in any one of claims 1-7; the preparation method includes... Substrate (100) is provided; An epitaxial structure (200) is formed on one side of the substrate (100) along a first direction, the first direction being the thickness direction of the substrate (100); the epitaxial structure (200) has a first surface (201) facing away from the substrate (100). A ridge waveguide layer (300) is formed on the first surface (201), and the ridge waveguide layer (300) extends along a second direction, which is perpendicular to the first direction; A temperature control region (400) is formed on the first surface (201), and the temperature control region (400) is located on one side of the ridge waveguide layer (300) along a third direction, the third direction being perpendicular to the first direction and the second direction; the temperature control region (400) includes a P-type control layer (401) and an N-type control layer (402), the P-type control layer (401) and the N-type control layer (402) forming a PN junction; the temperature control region (400) can form an electric field in the epitaxial structure (200) when a voltage is applied, the electric field being used to limit the lateral diffusion of charge carriers in the epitaxial structure (200).

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