Semiconductor laser
By setting crisscrossing grooves and heat dissipation holes on the substrate surface of the semiconductor laser, the problems of substrate warping and heat dissipation are solved, the adhesion and heat dissipation ability of the device are improved, and the service life is extended.
Patent Information
- Application Number
- CN202422659989.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-10-31
AI Technical Summary
In semiconductor lasers, poor substrate warping and heat dissipation performance lead to low device reliability, and poor adhesion between metal electrodes and substrates, which easily leads to device shedding and heat difficulty dissipation.
A plurality of first grooves and second grooves are arranged on the second surface of the substrate, and heat dissipation holes are provided therebetween, and metal electrodes cover these surfaces, increasing adhesion and improving heat dissipation.
It improves the adhesion between the metal electrode and the substrate, reduces warpage, enhances heat dissipation effect, extends the service life of the device, and improves stability and reliability.
Smart Images
Figure CN223273663U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductors, in particular to a semiconductor laser. Background Art
[0002] In semiconductor lasers, the heat dissipation performance of the active area material will affect the life of the device. When the temperature of the active area is much higher than the ambient temperature, the excessively high temperature can easily lead to performance failure of the device. Therefore, lowering the temperature of the active area is an important method to improve device reliability. However, in current semiconductor lasers, after the substrate is thinned and polished, a metal electrode is usually directly evaporated on the entire surface of the back side of the substrate, which causes severe warping of the substrate and also leads to poor adhesion between the metal electrode and the substrate, which easily causes the device and the package component to fall off, thereby causing module failure. In addition, since the entire surface of the back side of the substrate is evaporated with a metal electrode, and the distance between the active area and the metal electrode (or the thickness of the substrate) is large, the heat generated in the active area is difficult to dissipate in time, making the operating temperature of the active area much higher than the ambient temperature, thereby increasing the risk of device failure. Utility Model Content
[0003] The purpose of the utility model is to provide a semiconductor laser to reduce the warping of the substrate surface and improve the heat dissipation effect of the semiconductor laser.
[0004] To achieve the above object, the present invention provides a semiconductor laser comprising:
[0005] A substrate and an active area located in the substrate, the substrate having a first surface and a second surface disposed opposite to each other, a plurality of first grooves and a plurality of second grooves crisscrossing each other between the active area and the second surface of the substrate, a heat dissipation hole being provided between two adjacent first grooves and two adjacent second grooves, wherein the bottoms of the first grooves, the second grooves, and the heat dissipation holes are all spaced from the active area, and the spacing between the bottoms of the heat dissipation holes and the active area is smaller than the spacing between the bottoms of the first grooves and the second grooves and the active area;
[0006] A metal electrode covers the inner surface of the first groove, the inner surface of the second groove, the inner surface of the heat dissipation hole and the second surface of the substrate.
[0007] Optionally, the length directions of the plurality of first grooves all extend along the first direction, and the plurality of first grooves are arranged in parallel along the second direction, and the first direction and the second direction are perpendicular to each other.
[0008] Optionally, the length directions of the plurality of second grooves all extend along the second direction, and the plurality of second grooves are arranged in parallel along the first direction.
[0009] Optionally, each of the second grooves penetrates the plurality of first grooves in the region along the second direction and is connected with the plurality of first grooves.
[0010] Optionally, the cross-sectional shape of the first groove and the cross-sectional shape of the second groove are both V-shaped.
[0011] Optionally, the first surface of the substrate has a ridge waveguide, and the substrate on both sides of the ridge waveguide has a third groove.
[0012] Optionally, there are more than two heat dissipation holes between two adjacent first grooves and two adjacent second grooves, and the projection of at least one heat dissipation hole on the second surface of the substrate overlaps with the projection of the ridge waveguide on the second surface of the substrate.
[0013] Optionally, a projection of at least one of the heat dissipation holes on the second surface of the substrate is located around a projection of the ridge waveguide on the second surface of the substrate.
[0014] Optionally, the cross-sectional shape of the heat dissipation hole is rectangular or trapezoidal.
[0015] Optionally, the width of the heat dissipation hole is greater than the width of the ridge waveguide.
[0016] In the semiconductor laser provided by the present invention, by providing a plurality of first grooves and a plurality of second grooves crisscrossing between the active area and the second surface of the substrate, the roughness of the second surface of the substrate can be increased, the adhesion between the metal electrode and the second surface of the substrate can be improved, and the stress in the substrate can be effectively released, the warping of the second surface of the substrate can be reduced, and the reliability of the device can be improved. In addition, there is a heat dissipation hole between two adjacent first grooves and two adjacent second grooves, and the metal electrode covers the inner surface of the first groove, the inner surface of the second groove, the inner surface of the heat dissipation hole and the second surface of the substrate. By providing the heat dissipation hole, the distance between the active area and the metal electrode can be reduced, so that the heat generated by the active area can more easily pass through the substrate to reach the metal electrode and be quickly conducted away by the metal electrode, thereby improving the heat dissipation effect of the semiconductor laser, enhancing the heat dissipation capacity of the semiconductor laser, thereby extending the service life of the device, and improving the stability and reliability of the device. Furthermore, due to the presence of the first groove, the second groove and the heat dissipation hole, the contact area between the metal electrode and the substrate per unit area is increased, thereby reducing the contact resistance between the metal electrode and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 1 is a top view of a semiconductor laser according to an embodiment of the present utility model;
[0018] Figure 2 It is along Figure 1 Schematic diagram of the cross-sectional structure in the A-A' direction;
[0019] Figure 3 It is along Figure 1 Schematic diagram of the cross-sectional structure in the BB' direction;
[0020] Figures 4 to 7 This is a schematic structural diagram of the semiconductor laser when forming the first groove, the second groove and the heat dissipation hole in an embodiment of the utility model;
[0021] The description of the accompanying drawings is as follows:
[0022] 100 - substrate; 100a - first surface; 100b - second surface; 101 - active area; 102 - first groove; 103 - second groove; 104 - heat dissipation hole;
[0023] 110-ridge waveguide; 111-third groove;
[0024] 120 - a patterned first photoresist layer;
[0025] 130 - patterned second photoresist layer;
[0026] 140-Metal electrode. DETAILED DESCRIPTION
[0027] The semiconductor laser proposed in this utility model is further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this utility model will become more apparent from the following description. It should be noted that the accompanying drawings are highly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of this utility model.
[0028] As used in the present invention, the singular forms "a", "an", and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly specifying the number of the indicated technical features. Therefore, the features specified as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features.
[0029] Figure 11 is a top view of a semiconductor laser according to an embodiment of the present invention. Figure 2 It is along Figure 1 Schematic diagram of the cross-sectional structure in the A-A' direction. Figure 1 Combined with Figure 2 As shown, the semiconductor laser provided by this embodiment includes a substrate 100 , an active region 101 located in the substrate 100 , and a metal electrode 140 .
[0030] Specifically, such as Figure 2 As shown, the substrate 100 has a first surface 100a and a second surface 100b opposite to each other. The substrate 100 may be a substrate 100 that has undergone a thinning process and a polishing process, i.e., the second surface 100b of the substrate 100 is thinned by the thinning process, and the second surface 100b of the substrate 100 is polished by the polishing process. The material of the substrate 100 may be indium phosphide (InP), the first surface 100a of the substrate 100 may be the front surface of the substrate 100, and the second surface 100b of the substrate 100 may be the back surface of the substrate 100.
[0031] In this embodiment, the active region 101 is located between the first surface 100a and the second surface 100b of the substrate 100. The distance between the active region 101 and the first surface 100a of the substrate 100 is smaller than the distance between the active region 101 and the second surface 100b of the substrate 100, that is, the active region 101 is closer to the first surface 100a of the substrate 100. The active region 101 may include a multi-layer quantum well layer, or the active region 101 may be a multi-quantum well region or a superlattice structure. The active region 101 may serve as a light-emitting region of a semiconductor laser, that is, the active region 101 is a heat concentration region. Furthermore, the active region 101 may also include other device layers such as a cladding layer and a contact layer, but is not limited thereto and may be configured according to actual device requirements.
[0032] For further reference, Figure 2 As shown, the first surface 100a of the substrate 100 has a ridge waveguide 110, and the substrate 100 has third grooves 111 on both sides of the ridge waveguide 110. In an actual manufacturing process, the ridge waveguide 110 can be formed by an aluminum oxide epitaxial layer, that is, an aluminum oxide epitaxial layer is first formed on the first surface 100a of the substrate 100 through an epitaxial process, and then the aluminum oxide epitaxial layer is etched to form the ridge waveguide 110 and the third groove 111.
[0033] Figure 3 It is along Figure 1 Schematic diagram of the cross-sectional structure in the B-B' direction. Figure 3 Combined with Figure 1 and Figure 2As shown, a plurality of first grooves 102 and a plurality of second grooves 103 are arranged in a crisscross pattern between the active area 101 and the second surface 100b of the substrate 100. The bottoms of the first grooves 102 and the bottoms of the second grooves 103 are both spaced apart from the active area 101. By providing the plurality of first grooves 102 and the plurality of second grooves 103 in a crisscross pattern, the roughness of the second surface 100b of the substrate 100 can be increased, the adhesion of the metal electrode 140 can be improved, and the close bonding between the metal electrode 140 and the second surface 100b of the substrate 100 can be ensured. The stress in the substrate 100 can also be effectively released, thereby effectively reducing the stress generated on the second surface 100b of the substrate 100 during the thinning process and reducing the warping of the second surface 100b of the substrate 100. This can improve the reliability of the device and enhance the operational safety of the substrate 100 in subsequent manufacturing processes.
[0034] like Figure 2 and Figure 3 As shown, the first groove 102 and the second groove 103 both extend from the second surface 100b of the substrate 100 into the substrate 100, and the depth of the first groove 102 is the same as the depth of the second groove 103. Figure 1 As shown, the length directions of the plurality of first grooves 102 all extend along the first direction X, and the plurality of first grooves 102 are arranged in parallel along the second direction Y, with the first direction X and the second direction Y being perpendicular to each other. The length directions of the plurality of second grooves 103 all extend along the second direction Y, and the plurality of second grooves 103 are arranged in parallel along the first direction X. Each second groove 103 extends through the plurality of first grooves 102 in the region in which it is located along the second direction Y and is connected to the plurality of first grooves 102.
[0035] Preferably, the cross-sectional shape of the first groove 102 and the cross-sectional shape of the second groove 103 are both V-shaped. In this way, the area of the substrate 100 occupied by the first groove 102 and the second groove 103 can be reduced, which is conducive to improving the integration of the device.
[0036] In the actual manufacturing process, the first groove 102 and the second groove 103 can be formed on the second surface 100b of the substrate 100 by a wet etching process to ensure process stability. Figure 4 As shown, a patterned first photoresist layer 120 may be formed on the second surface 100b of the substrate 100, wherein the patterned first photoresist layer 120 has a plurality of first openings and second openings that are crisscrossed; then, as shown in FIG. Figure 5As shown, the second surface 100 b of the substrate 100 is etched by a wet etching process using the patterned first photoresist layer 120 as a mask, thereby forming a plurality of first grooves 102 and a plurality of second grooves 103 that are crisscrossed.
[0037] like Figure 1 As shown, a heat dissipation hole 104 is provided between two adjacent first grooves 102 and two adjacent second grooves 103. That is, the heat dissipation hole 104 is located in the portion of the substrate 100 surrounded by the two adjacent first grooves 102 and the two adjacent second grooves 103. Due to the provision of the heat dissipation hole 104, the heat generated by the active area 101 can easily pass through the substrate 100, thereby being promptly conducted away from the active area 101.
[0038] In this embodiment, the heat dissipation hole 104 is spaced from the second groove 103 , that is, the heat dissipation hole 104 and the second groove 103 are not connected, and the heat dissipation hole 104 is spaced from the first groove 102 , that is, the heat dissipation hole 104 and the first groove 102 are not connected.
[0039] like Figure 2 and Figure 3 As shown, the heat dissipation hole 104 extends from the second surface 100b of the substrate 100 into the substrate 100, and the bottom of the heat dissipation hole 104 is spaced apart from the active area 101. In this way, while improving the heat dissipation effect of the semiconductor laser, it can avoid affecting the devices located on the first surface 100a of the substrate 100.
[0040] Preferably, Figure 2 and Figure 3 As shown, the distance between the bottom of the heat dissipation hole 104 and the active area 101 is smaller than the distance between the bottom of the first groove 102 and the bottom of the second groove 103 and the active area 101, that is, the depth of the heat dissipation hole 104 is greater than the depth of the first groove 102, or in other words, the depth of the heat dissipation hole 104 is greater than the depth of the second groove 103. In this way, the distance between the active area 101 and the bottom of the heat dissipation hole 104 can be reduced, which is conducive to improving the heat dissipation of the active area 101.
[0041] In this embodiment, Figure 1 As shown, there are two or more heat dissipation holes 104 between two adjacent first grooves 102 and two adjacent second grooves 103 to quickly dissipate heat from the second surface 100b of the substrate 100 and improve heat dissipation efficiency. Figure 2As shown, in this embodiment, three heat dissipation holes 104 are provided between two adjacent first grooves 102 and two adjacent second grooves 103 as an example, but it is not limited thereto. The number of heat dissipation holes 104 between two adjacent first grooves 102 and two adjacent second grooves 103 can be four, five or six.
[0042] In further solutions, such as Figure 2 As shown, the projection of at least one of all the heat dissipation holes 104 on the second surface 100b of the substrate 100 overlaps with the projection of the ridge waveguide 110 on the second surface 100b of the substrate 100, that is, at least one of the heat dissipation holes 104 is located above the ridge waveguide 110. In this way, the position of the heat dissipation hole 104 on the second surface 100b of the substrate 100 can be made closer to the heat concentration area of the active area 101, so that the heat accumulated in the active area 101 can be conducted out in time.
[0043] Furthermore, the projection of at least one of the heat dissipation holes 104 on the second surface 100b of the substrate 100 is located around the projection of the ridge waveguide 110 on the second surface 100b of the substrate 100. For example, among all the heat dissipation holes 104, only one specific heat dissipation hole may be located above the ridge waveguide 110, while the projections of all other heat dissipation holes 104 on the second surface 100b of the substrate 100 are distributed around the projection of the ridge waveguide 110 on the second surface 100b of the substrate 100. In this way, the heat dissipation holes 104 on the second surface 100b of the substrate 100 can be located relatively close to the heat concentration area of the active area 101, so that the heat accumulated within the active area 101 can be promptly transferred out.
[0044] In this embodiment, the width of the heat dissipation hole 104 can be greater than the width of the ridge waveguide 110. The cross-section of the heat dissipation hole 104 (i.e., the cross-section in the vertical direction of the substrate 100) can be rectangular. In specific implementations, the shape of the heat dissipation hole 104 can also be designed to have other shapes according to different specific application scenarios. For example, the cross-section of the heat dissipation hole 104 can be trapezoidal.
[0045] In the actual manufacturing process, the heat dissipation holes 104 can be formed on the second surface 100b of the substrate 100 by a dry etching process. The dry process can accurately control the etching depth to avoid damaging the active area 101. Figure 6As shown, in the process of forming the heat dissipation hole 104, a patterned second photoresist layer 130 is first formed. The patterned second photoresist layer 130 covers the inner surfaces of the first groove 102 and the second groove 103, and covers a portion of the second surface 100b of the substrate 100, and exposes a portion of the second surface 100b of the substrate 100 above the ridge waveguide 110 and the third groove 111; then, as shown in FIG. Figure 7 As shown, the patterned second photoresist layer 130 is used as a mask, and the exposed second surface 100 b of the substrate 100 is etched by a dry etching process to form the heat dissipation hole 104 , and the patterned second photoresist layer 130 is removed.
[0046] refer to Figure 1 and combined Figure 2 and Figure 3 As shown, the metal electrode 140 covers the inner surface of the first groove 102 (i.e., the bottom and sidewalls of the first groove 102), the inner surface of the second groove 103 (i.e., the bottom and sidewalls of the second groove 103), the inner surface of the heat dissipation hole 104 (i.e., the bottom and sidewalls of the heat dissipation hole 104), and the second surface 100b of the substrate 100. In this way, the distance between the active area 101 and the metal electrode 140 is reduced, that is, the active area 101 is closer to the metal electrode 140, so that the heat generated by the active area 101 can more easily pass through the substrate 100 to reach the metal electrode 140 and be quickly conducted away by the metal electrode 140, thereby improving the heat dissipation effect of the semiconductor laser and enhancing the heat dissipation capacity of the semiconductor laser, thereby extending the service life of the device and improving the stability and reliability of the device. Furthermore, due to the presence of the first groove, the second groove 103 and the heat dissipation hole 104, the contact area between the metal electrode 140 and the substrate 100 per unit area is increased, thereby reducing the contact resistance between the metal electrode 140 and the substrate, and at the same time, the series resistance in the device can also be reduced.
[0047] In a further embodiment, the metal electrode 140 may fill the first groove 102 and the second groove 103 .
[0048] Optionally, the material of the metal electrode 140 can be a high thermal conductivity material, such as Cu (copper), Ni (nickel), Ge (germanium) or Pt (platinum), wherein the metal electrode 140 can be formed by an evaporation process, a sputtering process or an electroplating process.
[0049] In summary, it can be seen that in the semiconductor laser provided by the embodiment of the present invention, by providing a plurality of first grooves and a plurality of second grooves crisscrossing between the active area and the second surface of the substrate, the roughness of the second surface of the substrate can be increased, thereby effectively releasing the stress in the substrate, reducing the warping of the second surface of the substrate, and thus improving the reliability of the device. In addition, there is a heat dissipation hole between adjacent first grooves and adjacent second grooves, and the metal electrode covers the inner surface of the first groove, the inner surface of the second groove, the inner surface of the heat dissipation hole and the second surface of the substrate. By providing the heat dissipation hole, the distance between the active area and the metal electrode can be reduced, so that the heat generated by the active area can more easily pass through the substrate to reach the metal electrode and be quickly conducted away by the metal electrode, thereby improving the heat dissipation effect of the semiconductor laser, enhancing the heat dissipation capacity of the semiconductor laser, thereby extending the service life of the device, and improving the stability and reliability of the device. Furthermore, due to the presence of the first groove, the second groove and the heat dissipation hole, the contact area between the metal electrode and the substrate per unit area is increased, thereby reducing the contact resistance between the metal electrode and the substrate.
[0050] Furthermore, it should be recognized that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. Any person skilled in the art will be able to utilize the above-disclosed technical content to make numerous possible variations and modifications to the present invention, or to modify the present invention into equivalent embodiments with equivalent variations, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.
Claims
1. A semiconductor laser, characterized in that include: A substrate and an active area located in the substrate, the substrate having a first surface and a second surface disposed opposite to each other, a plurality of first grooves and a plurality of second grooves crisscrossing each other between the active area and the second surface of the substrate, a heat dissipation hole being provided between two adjacent first grooves and two adjacent second grooves, wherein the bottoms of the first grooves, the second grooves, and the heat dissipation holes are all spaced from the active area, and the spacing between the bottoms of the heat dissipation holes and the active area is smaller than the spacing between the bottoms of the first grooves and the second grooves and the active area; A metal electrode covers the inner surface of the first groove, the inner surface of the second groove, the inner surface of the heat dissipation hole and the second surface of the substrate.
2. The semiconductor laser according to claim 1, wherein The length directions of the plurality of first grooves all extend along a first direction, and the plurality of first grooves are arranged in parallel along a second direction, and the first direction and the second direction are perpendicular to each other.
3. The semiconductor laser according to claim 2, wherein The length directions of the plurality of second grooves all extend along the second direction, and the plurality of second grooves are arranged in parallel along the first direction.
4. The semiconductor laser according to claim 3, wherein Each of the second grooves penetrates the plurality of first grooves in the region along the second direction and is connected with the plurality of first grooves.
5. The semiconductor laser according to claim 1 or 4, wherein: The cross-sectional shape of the first groove and the cross-sectional shape of the second groove are both V-shaped.
6. The semiconductor laser according to claim 1, wherein A ridge waveguide is provided on the first surface of the substrate, and third grooves are provided in the substrate on both sides of the ridge waveguide.
7. The semiconductor laser according to claim 6, wherein There are more than two heat dissipation holes between two adjacent first grooves and two adjacent second grooves, and a projection of at least one heat dissipation hole on the second surface of the substrate overlaps with a projection of the ridge waveguide on the second surface of the substrate.
8. The semiconductor laser according to claim 7, wherein A projection of at least one of the heat dissipation holes on the second surface of the substrate is located around a projection of the ridge waveguide on the second surface of the substrate.
9. The semiconductor laser according to claim 7 or 8, wherein The cross-sectional shape of the heat dissipation hole is rectangular or trapezoidal.
10. The semiconductor laser according to claim 7 or 8, wherein The width of the heat dissipation hole is greater than the width of the ridge waveguide.