Laser element

Abstract

A laser device includes a transparent substrate, an adhesive layer, and a laser unit. The transparent substrate includes a conductive layer. The adhesive layer is attached to the transparent substrate. The laser unit includes a front conductive structure and a back conductive structure. The front conductive structure is attached to the adhesive layer. The back conductive structure is opposite to the front conductive structure, and the back conductive structure includes a plurality of detection electrodes separated from each other. The plurality of detection electrodes extend from the back conductive structure, penetrate the front conductive structure and the adhesive layer, and are connected to the conductive layer.

Description

[0001] This application is a divisional application of Chinese invention patent application (application number: 201910846928.4, application date: September 9, 2019, invention title: laser element). Technical Field

[0002] This invention relates to a laser element and a method for manufacturing the same, and more particularly to a laser element with integrated monitoring circuitry and a method for manufacturing the same. Background Technology

[0003] A laser module is a laser light source assembled with laser elements, such as vertical cavity surface emitting lasers (VCSELs), and corresponding optical elements. However, if the laser module is subjected to external impact or drop during use, the optical elements may break, and the laser light emitted by the laser elements will leak out from the break without any optical processing, possibly shining directly into the human eye. Summary of the Invention

[0004] In view of this, some embodiments of the present invention provide a laser element and a method for manufacturing the same.

[0005] A laser element according to an embodiment of the present invention includes a transparent substrate, an adhesive layer, and a laser unit. The transparent substrate includes a conductive layer. The adhesive layer is connected to the transparent substrate. The laser unit includes a positive conductive structure, a back conductive structure, and a via. The positive conductive structure is connected to the adhesive layer. The back conductive structure is opposite to the positive conductive structure and includes a plurality of mutually separated detection electrodes. The via extends from the back conductive structure and penetrates the positive conductive structure and the adhesive layer; wherein the two ends of the via are respectively connected to the plurality of detection electrodes and the conductive layer.

[0006] Another embodiment of the laser element of the present invention includes a transparent substrate, an adhesive layer, a conductive region, and a laser unit. The adhesive layer is connected to the transparent substrate. The conductive region is disposed at the periphery of the adhesive layer. The laser unit includes a positive conductive structure, a back conductive structure, and a via. The positive conductive structure is connected to the adhesive layer. The back conductive structure is opposite to the conductive structure and includes a plurality of mutually separated detection electrodes. The via extends from the back conductive structure and penetrates the positive conductive structure; wherein the two ends of the via are respectively connected to the plurality of detection electrodes and the conductive region, and the conductive regions surround the laser unit and are electrically separated from each other.

[0007] The following detailed description, in conjunction with the accompanying drawings, provides a clearer understanding of the purpose, technical content, features, and effects of this invention. Attached Figure Description

[0008] Figure 1This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0009] Figure 2 This is a schematic diagram of a laser element according to an embodiment of the present invention viewed from the top plane of AA'.

[0010] Figure 3 This is a schematic diagram of a laser element according to an embodiment of the present invention viewed from the top plane of AA'.

[0011] Figure 4 This is a schematic diagram of a laser element according to an embodiment of the present invention viewed from the top plane of AA'.

[0012] Figure 5A This is a schematic diagram of a laser element according to an embodiment of the present invention viewed from the top plane of AA'.

[0013] Figure 5B This is a schematic diagram of a laser element according to an embodiment of the present invention viewed from the top plane of AA'.

[0014] Figure 6 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0015] Figure 7 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0016] Figure 8 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0017] Figure 9 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0018] Figure 10 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0019] Figure 11 This is a schematic diagram of a laser element according to an embodiment of the present invention;

[0020] Figures 12 to 16 This is a schematic diagram illustrating the manufacturing steps of a laser element according to an embodiment of the present invention;

[0021] Figures 17 to 21 This is a schematic diagram illustrating the manufacturing steps of a laser element according to an embodiment of the present invention;

[0022] Figures 22 to 24 This is a schematic diagram illustrating the manufacturing steps of a laser element according to an embodiment of the present invention.

[0023] Symbol Explanation

[0024] 1 transparent substrate

[0025] Surfaces 1a and 1b

[0026] 10. Conductive layer

[0027] 12 Optical Structure

[0028] 2. Next layer

[0029] 3 laser units

[0030] 30 Positive Conductivity Structure

[0031] 31 Type I Semiconductor Layer

[0032] 32 Back Conductive Structure

[0033] 320 conductive via

[0034] Detection electrodes 321 and 322

[0035] 323, 324 conductive electrodes

[0036] 33 Active layer

[0037] 34 through holes

[0038] 340 passivation layer

[0039] 35 Type II Semiconductor Layer

[0040] 36 Protective Layer

[0041] 38 substrate

[0042] AA' Top View

[0043] L laser beam Detailed Implementation

[0044] The various embodiments of the present invention will be described in detail below, with reference to the accompanying drawings. In the description of the invention, many specific details are provided to give the reader a more complete understanding of the invention; however, the invention may still be practiced with some or all of these specific details omitted. The same or similar elements in the drawings will be represented by the same or similar symbols. It should be noted that the drawings are for illustrative purposes only and do not represent the actual size or number of elements; some details may not be fully drawn for the sake of simplicity.

[0045] Please refer to Figure 1A laser element according to an embodiment of the present invention includes a transparent substrate 1, an adhesive layer 2, and a laser unit 3. The transparent substrate 1 includes a conductive layer 10. For example, the transparent substrate includes sapphire, glass, or silicon carbide (SiC). In some embodiments, the transparent substrate 1 is an optical element, and may also produce specific optical effects through patterning, but is not limited thereto. The conductive layer 10 includes a transparent conductive film or metal, wherein the transparent conductive film may be indium tin oxide (ITO) or indium zinc oxide (IZO). In this embodiment, the conductive layer 10 is disposed between the transparent substrate 1 and the adhesive layer 2, but is not limited thereto.

[0046] Next, layer 2 is connected to the conductive layer 10 of the transparent substrate 1 on one side and to the light-emitting side of the laser unit 3 on the other side. For example, the adhesive layer is benzene (BCB), silicon dioxide, or a transparent conductive film, but is not limited thereto.

[0047] The laser unit 3 includes a positively conductive structure 30, a first-type semiconductor layer 31, an active layer 33, a second-type semiconductor layer 35, a protective layer 36, and a back-conductive structure 32. The back-conductive structure 32 includes a first conductive electrode 323 and a second conductive electrode 324 that are separated from each other. Here, "first-type" and "second-type" refer to semiconductor structures with different electrical properties. If a semiconductor structure has holes as the majority carrier, it is a p-type semiconductor; if a semiconductor structure has electrons as the majority carrier, it is an n-type semiconductor. For example, the first-type semiconductor layer is an n-type semiconductor, and the second-type semiconductor layer is a p-type semiconductor, and vice versa. Since the second-type semiconductor layer 35 is grown on the first-type semiconductor layer 31 with different electrical properties, a pn junction will be formed at the interface between the two, generating a depletion region for light emission. An active layer 33 can be defined in the region adjacent to the pn junction. In some embodiments, the active layer 33 includes multiple quantum wells to improve luminous efficiency, but this is not a limitation. In one embodiment, the materials of the first type semiconductor layer 31, the second type semiconductor layer 35, and the active layer 33 comprise group III-V compound semiconductors, such as GaAs, InGaAs, AlGaAs, AlInGaAs, GaP, InGaP, AlInP, AlGaInP, GaN, InGaN, AlGaN, AlInGaN, AlAsSb, InGaAsP, InGaAsN, AlGaAsP, etc. In embodiments of the present invention, unless otherwise specified, the above chemical formulas include "compounds conforming to stoichiometry" and "compounds not conforming to stoichiometry," wherein, for example, a "compound conforming to stoichiometry" is one in which the total elemental dose of group III elements is the same as that of group V elements, and conversely, a "compound not conforming to stoichiometry" is one in which the total elemental dose of group III elements is different from that of group V elements. For example, the chemical formula AlGaAs represents compounds containing group III elements aluminum (Al) and / or gallium (Ga) and group V elements arsenic (As), wherein the total elemental dosage of group III elements (aluminum and / or gallium) may be the same as or different from the total elemental dosage of group V elements (arsenic). Furthermore, if the compounds represented by the above chemical formulas are compounds that conform to stoichiometry, AlGaAs represents Al x1 Ga (1-x1) As, where 0≤x1≤1; AlInP represents Al x2 In (1-x2) P, where 0 ≤ x² ≤ 1; AlGaInP represents (Al y1 Ga (1-y1) ) 1-x3 In x3 P, where 0 ≤ x³ ≤ 1, 0 ≤ y¹ ≤ 1; AlGaN represents Al x4 Ga(1-x4) N, where 0 ≤ x⁴ ≤ 1; AlAsSb represents AlAs x5 Sb (1-x5) Where 0 ≤ x5 ≤ 1; InGaP represents In x6 Ga 1-x6 P, where 0 ≤ x6 ≤ 1; InGaAsP represents In x7 Ga 1-x7 As 1-y2 P y2 Where 0 ≤ x7 ≤ 1, 0 ≤ y2 ≤ 1; InGaAsN represents In x8 Ga 1-x8 As 1-y3 N y3 Where 0 ≤ x8 ≤ 1, 0 ≤ y3 ≤ 1; AlGaAsP represents Al x9 Ga 1-x9 As 1-y4 P y4 Where 0 ≤ x ≤ 9 ≤ 1, 0 ≤ y ≤ 4 ≤ 1; InGaAs represents In x10 Ga 1-x10 As, where 0 ≤ x 10 ≤ 1. Depending on the material of the active layer 33, when the materials of the semiconductor stack 31 and 35 are AlGaInP series, the active layer 33 can emit infrared light with a peak wavelength between 700 and 1700 nm, red light between 610 nm and 700 nm, or yellow light with a peak wavelength between 530 nm and 570 nm. When the materials of the semiconductor stack 31 and 35 are InGaN series, the active layer 33 can emit blue light or deep blue light with a peak wavelength between 400 nm and 490 nm, or green light with a peak wavelength between 490 nm and 550 nm. When the materials of the semiconductor stack 31 and 35 are AlGaN series, the light-emitting layer 33 can emit ultraviolet light with a peak wavelength between 250 nm and 400 nm.

[0048] In this embodiment, the first semiconductor layer 31 and the second semiconductor layer 35 contain multiple overlapping layered structures to form a distributed Bragg reflector (DBR), so that the laser light L emitted by the active layer 33 can be reflected in the two distributed Bragg reflectors to form coherent light and then emitted toward the first semiconductor layer 31.

[0049] In one embodiment, a protective layer 36 is disposed between the back conductive structure 32 and the second type semiconductor layer 35. The protective layer 36 can function as an insulating layer, and in one embodiment, the material of the protective layer 36 comprises silicon oxide.

[0050] In one embodiment, an ohmic contact (not shown) is disposed between the back conductive structure 32 and the second type semiconductor layer 35 to facilitate the formation of an ohmic contact between the back conductive structure 32 and the second type semiconductor layer 35. The ohmic contact formation mechanism requires that the work function of the metal must be less than that of the semiconductor, allowing electrons to easily leap across this energy level from semiconductor to metal and from metal to semiconductor, enabling bidirectional current conduction. For example, the metal composition of the second conductive electrode 324 of the back conductive structure 32 is mainly titanium-aluminum alloy, because titanium can form titanium nitride with the group III-V compounds (such as aluminum gallium nitride) of the second type semiconductor layer, making the nitrogen atoms on the surface n-type doped. After high-temperature annealing, a good ohmic contact is formed, but this is not a limitation.

[0051] In one embodiment, a first type semiconductor layer 31 is connected to a positive conductive structure 30, which is connected to a first conductive electrode 323 via a conductive via 320. A second conductive electrode 324 is separated from the first conductive electrode 323 to avoid short circuits, and a second type semiconductor layer 35 is connected to the second conductive electrode 324. Through the aforementioned conductive structure, the laser unit 3 receives external driving voltage / current, providing the electrical energy required for the active layer 33 to generate laser light L. The positive conductive structure 30 is located on the light-emitting side of the laser unit 3 and connected to the bonding layer 2. Therefore, the laser light L emitted by the laser unit 3 will be output to the outside through the bonding layer 2 and the transparent substrate 1.

[0052] Because the coherent light emitted by the laser element has high initial energy, corresponding optical elements are required, such as a transparent substrate 1, to process and output laser light L of appropriate intensity. In order to effectively monitor whether the laser element is damaged and prevent the laser light L that has not been optically processed by the transparent substrate 1 from leaking out and shining directly into the human eye, the laser element of this embodiment has an eye safety monitoring circuit, which can monitor abnormal damage on the light-emitting side of the laser element in real time. The working principle of the laser element structure of some embodiments is illustrated below.

[0053] In this embodiment, in addition to the semiconductor structure required for emitting laser light, the laser unit 3 also includes a back conductive structure 32 and a through-hole 34. The back conductive structure 32 includes a plurality of detection electrodes 321, 322, and the back conductive structure 32 and the positive conductive structure 30 are disposed opposite to each other on both sides of the laser unit 3. The through-hole 34 extends from the back conductive structure 32 and penetrates the positive conductive structure 30 and the bonding layer 2, and is connected to the conductive layer 10. That is, the two ends of the through-hole 34 are respectively connected to the plurality of detection electrodes 321, 322 and the conductive layer 10. In some embodiments, the back conductive structure 32 includes a plurality of detection electrodes 321, 322 and a plurality of conductive electrodes 323, 324 that are separated from each other and coplanar, such as Figure 1As shown, the laser element is thus suitable for flip-chip packaging, eliminating the need for wire bonding processes and saving package size. In another embodiment, the back conductive structure 32 includes a plurality of detection electrodes 321, 322, which extend from the back conductive structure and penetrate the positive conductive structure and the bonding layer, and are connected to the conductive layer 10.

[0054] Please refer to the above as well. Figure 1 and Figure 2 ,in Figure 2 Display along Figure 1 The schematic diagram shown is a top view of AA' looking downwards. Multiple separate detection electrodes 321 and 322 are connected across the two ends of the conductive layer 10 via through-holes 34. Therefore, by connecting the multiple detection electrodes 321 and 322 to an external control circuit, the resistance change of the conductive layer 10 can be monitored in real time. When the laser element is damaged by external impact, especially when the transparent substrate 1, which is the light-emitting side, is damaged, the conductive layer 10 will also be damaged, resulting in an increased resistance value, or even a broken circuit. Therefore, the control circuit, through the monitoring circuit, determines whether to cut off the power supply to the laser unit 3 based on the change in the resistance value of the conductive layer 10, to prevent the laser light L emitted by the laser unit 3 from leaking through the damaged gaps in the transparent substrate 1 and directly irradiating the human eye, thereby achieving the effect of real-time monitoring of abnormal conditions.

[0055] In another embodiment, to prevent the conductive medium filling the via 320 from coming into contact with the positive conductive structure 30, the first type semiconductor layer 31, or the second type semiconductor layer 35 of the laser unit 3 and forming a short circuit, the laser unit 3 further includes a passivation layer 340 disposed on the inner wall of the via 320, so as to avoid the electrical interference of the laser unit 3 on the resistance value measured by the via, and reduce the measurement noise.

[0056] As can be seen from the above description, the laser element in some embodiments of the present invention integrates the monitoring circuit composed of the conductive layer, through hole and detection electrode into the laser unit structure. The laser element with built-in monitoring circuit is produced by integral molding semiconductor manufacturing process. Therefore, it can save the packaging volume of the module end, simplify the modularization process and reduce the production cost.

[0057] Please refer to Figure 3 Display along Figure 1 The schematic diagram shown is a cross-sectional view of AA' viewed from above. In one embodiment, to expand the monitoring range, the conductive layer 10 has a large area, almost covering the transparent substrate 1. Please refer to... Figure 4 Display along Figure 1The diagram shows a cross-sectional view of AA' viewed from above. In one embodiment, the conductive layer 10 surrounds the periphery of the transparent substrate 1 and has a hollow area corresponding to the light emission aperture (not shown) of the laser unit 3 below, to prevent the laser light L emitted by the laser unit 3 from being blocked by the conductive layer 10. In this case, the conductive layer 10 can be made of an opaque material, such as a metal conductive layer, and is not limited to a transparent conductive layer. In some embodiments, using a metal conductive layer can have better conductivity, thereby improving the monitoring sensitivity without blocking the light emitted by the laser unit 3. Please refer to... Figure 5A Display along Figure 1 The diagram shows a cross-sectional view of AA' taken from a top-down perspective. In one embodiment, the multiple light-emitting holes of the laser unit 3 are arranged in an array, so the conductive layer 10 can avoid this light-emitting area and form a strip-shaped structure, such as... Figure 5A As shown. Please refer to... Figure 5B Display along Figure 1 The diagram shows a cross-sectional view of AA' viewed from above. In this embodiment, the multiple light-emitting holes of the laser unit 3 are arranged in a staggered manner, so the conductive layer 10 can avoid this light-emitting area and form a serpentine geometric structure. The above embodiments are merely illustrative examples of how to design the conductive layer, and can also be applied to the laser element structures of other embodiments in this document, but are not limited thereto.

[0058] Please refer to Figure 6 In one embodiment, the laser element differs from the structures of the various embodiments described above in that the conductive layer 10 is disposed on the transparent substrate 1 on the side opposite to the bonding layer 2, i.e., on the light-emitting side of the laser element. Therefore, the bonding layer 2 is connected to the transparent substrate 1 on one side and to the positive conductive structure 30 of the laser unit 3 on the other side. To effectively monitor the resistance change of the conductive layer 10, a via 34 further penetrates the bonding layer 2 and the transparent substrate 1. Thus, multiple mutually separated detection electrodes 321 and 322 are connected across the two ends of the conductive layer 10 through the via 34, facilitating the monitoring of the resistance change of the conductive layer 10. The structural features and connections of other components have been described above and will not be repeated here.

[0059] Please refer to Figure 7 In one embodiment, the laser element differs from the various embodiments described above in that multiple conductive layers 10 are simultaneously disposed on opposite sides of the transparent substrate 1, and the through-hole 34 penetrates the bonding layer 2, the transparent substrate 1, and at least one conductive layer 10, or simultaneously penetrates the conductive layers 10 on both sides of the transparent substrate 1. Therefore, when one or both conductive layers 10 are damaged, the resistance values ​​measured by the multiple detection electrodes 321 and 322 will change, thereby ensuring that both sides of the transparent substrate 1 (i.e., the optical element) are undamaged, preventing the leakage of laser light that has not been treated by the transparent substrate 1. The structural features and connections of other components have been described above.

[0060] Please refer to Figure 8 In one embodiment, the transparent substrate 1 further includes an optical structure 12 disposed on the side of the transparent substrate 1 opposite to the adhesive layer 2, that is, on the light-emitting side of the laser element. For example, the optical structure 12 is a diffractive optical element, which, together with the laser unit 3, can generate tens of thousands of laser light spots, suitable for three-dimensional sensing or face recognition, but is not limited thereto.

[0061] Please refer to Figure 9 Another embodiment of the laser element of the present invention includes a transparent substrate 1, an adhesive layer 2, a conductive region 10, and a laser unit 3. The conductive region 10 includes a transparent conductive film, metal, or silicon monoxide, wherein the transparent conductive film may be indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto. The laser unit 3 includes a positive conductive structure 30, a first type semiconductor layer 31, an active layer 33, a second type semiconductor layer 35, a protective layer 36, and a back conductive structure 32. The component features, connection relationships, advantages, and related embodiments of the transparent substrate 1, positive conductive structure 30, first type semiconductor layer 31, active layer 33, via 34, passivation layer 340, second type semiconductor layer 35, protective layer 36, and back conductive structure 32 of the laser element have been described above. The difference between this embodiment and the various embodiments described above is that a ring-shaped conductive region 10 is used instead of a whole conductive layer to simplify the semiconductor fabrication process and improve production yield. That is, the conductive region 10 is located at the periphery of the adhesive layer 2. The conductive region 10 surrounds the laser unit 3 and is electrically separated from each other to avoid contact between the conductive region 10 and the laser unit 3, which could lead to a short circuit or interference with the monitoring circuit. In this embodiment, since the via 34 does not penetrate the adhesive layer and the transparent substrate 1, it is better controlled during the etching process. Furthermore, the conductive region 10 is formed after the via 34 is formed, which avoids the conductive material to be filled into the conductive region 10 being affected during the etching process.

[0062] Please refer to Figure 10 In one embodiment, the laser element is as follows: Figure 9The different structure in the illustrated embodiment is that the through-hole 34 penetrates the bonding layer 2, and the conductive region 10 is connected to the transparent substrate 1 and the through-hole 34 on both sides, respectively. Other component features are detailed above. In this embodiment, since the conductive region 10 is directly connected to the transparent substrate 1, abnormal conditions of the transparent substrate 1 can be sensitively monitored. Furthermore, the conductive region 10 is formed after the through-hole 34 is formed, which avoids the conductive material to be filled into the conductive region 10 being affected during the etching process.

[0063] Please refer to Figure 11 In one embodiment, the transparent substrate 1 of the laser element further includes an optical structure 12 disposed on the transparent substrate 1 on the side opposite to the bonding layer 2, that is, on the light-emitting side of the laser element. For example, the optical structure 12 is an optical element such as a diffraction optical element or a microlens, which, together with the laser unit 3, can generate tens of thousands of laser spots, and the related advantages and effects have been described above.

[0064] Please refer to the above as well. Figures 12 to 16 The following describes a method for manufacturing a laser element according to another embodiment of the present invention. First, a conductive layer 10 is formed on a transparent substrate 1, such as... Figure 12 As shown, for example, the transparent substrate 1 includes a first surface 1a and a second surface 1b opposite to each other, the conductive layer 10 is disposed on the first surface 1a, and the transparent substrate 1 faces the laser unit 3 with the first surface 1a, but is not limited thereto. The material composition, structural features, connection relationship between components and related embodiments of the conductive layer 10 and the transparent substrate 1 have been described above.

[0065] A transparent substrate 1 and a laser unit 3 are bonded together by an adhesive layer 2, such as... Figure 13 As shown. In one embodiment, the laser unit 3 includes a positively conductive structure 30, a first-type semiconductor layer 31, an active layer 33, a second-type semiconductor layer 35, and a protective layer 36 sequentially stacked on a substrate 38. In another embodiment, the substrate 38 is a wafer substrate to grow multiple laser units 3. Therefore, this embodiment allows for the following monitoring circuit growth steps and subsequent miniaturization packaging applications to be performed at the wafer level.

[0066] Remove one substrate 38 of laser unit 3, such as Figure 14 As shown, exposing the protective layer 36 will facilitate the subsequent formation of the back conductive structure; through an etching process, a through-hole 34 is etched through the laser unit 3 and the bonding layer 2 to expose part of the conductive layer 10, as shown. Figure 15 As shown.

[0067] Next, please refer to Figure 16A passivation layer 340 is formed on the inner wall of the through hole 34. The function and effect of the passivation layer have been described above. The through hole 34 is filled with a conductive medium and connected to the conductive layer 10 by a vapor deposition process. Finally, a back conductive structure 32 is formed on the surface of the protective layer 36 of the laser unit 3. The back conductive structure 32 includes a plurality of mutually separated detection electrodes 321 and 322, and the plurality of detection electrodes 321 and 322 are respectively connected to the through hole 34.

[0068] In one embodiment, the laser unit 3 is a flip-chip structure. Therefore, in the step of forming the back conductive structure 32, multiple conductive electrodes 323 and 324 are simultaneously formed, which are separated from and coplanar with the multiple detection electrodes 321 and 322. In addition, in the etching process, a conductive via 32 is simultaneously formed, and a passivation layer 340 and a conductive medium are filled by a vapor deposition process, so that the two ends of the conductive via 32 are respectively connected to the first detection electrode 323 of the positive conductive structure 30 and the back conductive structure 32. The structural features, connection relationships, advantages and effects of each component and related embodiments have been described above.

[0069] In one embodiment, the method of manufacturing a laser element further includes forming an optical structure on a transparent substrate on the side opposite to the adhesive layer. For example, the optical structure can be formed by a photolithography process or an adhesive process, wherein the component features of the optical structure and related embodiments have been described above.

[0070] Please refer to Figure 12 In some embodiments, the conductive layer 10 is formed on the first surface 1a of the transparent substrate 1, and the transparent substrate 1 is bonded to the adhesive layer 2 with its second surface 1b facing the laser unit, such as... Figure 6 As shown, the conductive layer 10 and the bonding layer 2 are respectively disposed on opposite sides of the transparent substrate 1. In this embodiment, through an etching process, the through-hole 34 penetrates the transparent substrate 1, and then through a vapor deposition process, a passivation layer 340 and a conductive medium are filled, so that the two ends of the through-hole 34 are respectively connected to multiple detection electrodes 321 and 322 of the positive conductive structure 30 and the back conductive structure 32, as shown. Figure 16 As shown.

[0071] Please refer to the above as well. Figures 17 to 21 The following describes a method for manufacturing a laser element according to another embodiment of the present invention. First, a transparent substrate 1 and a laser unit 3 are bonded together with an adhesive layer, as follows: Figure 17 As shown. In one embodiment, the laser unit 3 includes a positively conductive structure 30, a first-type semiconductor layer 31, an active layer 33, a second-type semiconductor layer 35, and a protective layer 36 sequentially stacked on a substrate 38. The structural features, material composition, advantages, effects, and related embodiments of the above-mentioned components have been described above.

[0072] Remove one substrate 38 of laser unit 3, such as Figure 18 As shown, exposing the protective layer 36 will facilitate the subsequent formation of the back conductive structure; through an etching process, a through-hole 34 is etched through the laser unit 3 to expose part of the bonding layer 2, as shown. Figure 19 As shown.

[0073] A conductive region 10 is formed around the periphery of the laser unit 3, and is electrically separated from it, such as... Figure 20 As shown, this is to avoid electrical interference from the laser unit 3 to the conductive areas 10 or to prevent them from forming short circuits with each other.

[0074] Next, please refer to Figure 21 A passivation layer 340 is formed on the inner wall of the through hole 34. The function and effect of the passivation layer have been described above. The through hole 34 is filled with a conductive medium and connected to the conductive region 10 by a vapor deposition process. Finally, a back conductive structure 32 is formed on the surface of the protective layer 36 of the laser unit 3. The back conductive structure 32 includes a plurality of mutually separated detection electrodes 321 and 322, and the plurality of detection electrodes 321 and 322 are respectively connected to the through hole 34.

[0075] In one embodiment, the laser unit 3 is a flip-chip structure. Therefore, in the step of forming the back conductive structure 32, multiple conductive electrodes 323 and 324 are simultaneously formed, which are separated from and coplanar with the multiple detection electrodes 321 and 322. In addition, in the etching process, a conductive via 32 is simultaneously formed, and a passivation layer 340 and a conductive medium are filled by a vapor deposition process, so that the two ends of the conductive via 32 are respectively connected to the first detection electrode 323 of the positive conductive structure 30 and the back conductive structure 32. The structural features, connection relationships, advantages and effects of each component and related embodiments have been described above.

[0076] Please refer to Figure 21 In one embodiment, the method of manufacturing a laser element further includes forming an optical structure (not shown) on the side opposite to the bonding layer 2 on a transparent substrate 1. For example, the optical structure can be formed by a photolithography process or an adhesive process, wherein the component features of the optical structure and its related embodiments have been described above.

[0077] Please refer to the above as well. Figure 22 and Figure 24 In some embodiments, an etching process is used to etch through-holes 34 through the laser unit 3 and the bonding layer to expose a portion of the transparent substrate 1, such as... Figure 22 As shown.

[0078] Please refer to Figure 23In this embodiment, a conductive region 10 is formed around the laser unit 3, and the conductive region 10 is directly disposed on the transparent substrate 1, thereby more sensitively monitoring whether there are any abnormal conditions such as damage to the transparent substrate 1. The conductive region 10 is electrically separated from the laser unit 3 to avoid the conductive region 10 being subject to electrical interference from the laser unit 3 or forming a short circuit with each other.

[0079] Please refer to Figure 24 Next, a passivation layer 340 is formed on the inner wall of the through hole 34. The function and effect of the passivation layer have been described above. Through a vapor deposition process, a conductive medium is used to fill the through hole 34 and connect it to the conductive region 10. Finally, a back conductive structure 32 is formed on the surface of the protective layer 36 of the laser unit 3. The back conductive structure 32 includes a plurality of mutually separated detection electrodes 321 and 322, and the plurality of detection electrodes 321 and 322 are respectively connected to the through hole 34.

[0080] In one embodiment, the laser unit 3 is a flip-chip structure. Therefore, in the step of forming the back conductive structure 32, multiple conductive electrodes 323 and 324 are simultaneously formed, which are separated from and coplanar with the multiple detection electrodes 321 and 322. In addition, in the etching process, a conductive via 32 is simultaneously formed, and a passivation layer 340 and a conductive medium are filled by a vapor deposition process, so that the two ends of the conductive via 32 are respectively connected to the first detection electrode 323 of the positive conductive structure 30 and the back conductive structure 32. The structural features, connection relationships, advantages and effects of each component and related embodiments have been described above.

[0081] In one embodiment, the method of manufacturing a laser element further includes forming an optical structure (not shown) on the side of a transparent substrate 1 opposite to the adhesive layer 2. For example, the optical structure can be formed by a photolithography process or an adhesive process, wherein the component features of the optical structure and its related embodiments have been described above.

[0082] In summary, some embodiments of the present invention provide a laser element and its manufacturing method. The main feature is the integration of a monitoring circuit, comprised of the conductive layer / conductive region, vias, and detection electrodes, into a single laser unit structure. An external control circuit connects to the monitoring circuit within the laser element, determining whether to cut off the power supply to the laser unit based on changes in the resistance of the conductive layer / conductive region. This prevents the laser light emitted by the laser unit from leaking through gaps in the transparent substrate and directly irradiating the human eye, thereby achieving eye safety monitoring and protection. Simultaneously, the integrated component manufacturing process can save on module packaging volume, simplify module packaging processes, and reduce production costs. For example, using wafer-level semiconductor manufacturing processes, laser elements with built-in monitoring circuits can be produced, suitable for flip-chip packaging, eliminating the need for wire bonding processes, thus saving packaging volume and facilitating subsequent miniaturization applications.

[0083] The embodiments described above are merely for illustrating the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. That is, all equivalent changes or modifications made in accordance with the spirit disclosed in the present invention should still be covered within the scope of protection of the present invention.

Claims

1. A laser element, characterized in that, The laser element includes: Transparent substrate; A first conductive layer is connected to the light-transmitting substrate; Next, the layer is connected to the first conductive layer; and Laser unit, comprising: A positively conductive structure is connected to the bonding layer; The back conductive structure, opposite to the positive conductive structure, includes multiple electrode structures that are separated from each other; The second through hole extends from the back conductive structure, penetrates the bonding layer, and connects to the first conductive layer. as well as A passivation layer is disposed on the inner wall of the second through hole and directly connected to the first conductive layer.

2. The laser element as claimed in claim 1, wherein the plurality of electrode structures of the back conductive structure are separated from each other and coplanar, and the laser unit further includes a first through hole, the two ends of which are respectively connected to at least one of the plurality of electrode structures of the positive conductive structure and the back conductive structure.

3. The laser element as claimed in claim 1, further comprising a second conductive layer connected to the light-transmitting substrate opposite to the first conductive layer, and the second through-hole penetrating the light-transmitting substrate and connecting to the second conductive layer.

4. The laser element of claim 3, wherein the second conductive layer comprises a plurality of optical structures.

5. The laser element of claim 1, wherein the conductive layer is formed with a serpentine geometry.

6. The laser element as claimed in claim 1, wherein, viewed from a top view of the laser element, the at least one second through-hole is "L"-shaped.

7. A laser element, characterized in that, The laser element includes: Transparent substrate; A conductive layer is attached to the light-transmitting substrate; Next, a layer is attached to the light-transmitting substrate and the conductive layer; and A laser unit, which is attached to the light-transmitting substrate via the adhesive layer, comprises: A positively conductive structure is connected to the bonding layer; A first type of semiconductor layer, wherein the positively conductive structure is located on the first type of semiconductor layer; Type II semiconductor layer; An active layer is connected between the first type semiconductor layer and the second type semiconductor layer; The second conductive electrode is disposed on the second type semiconductor layer and opposite to the active layer; The third and fourth conductive electrodes are connected to the conductive layer and each extends from the side of the laser unit toward the second conductive electrode; and The first conductive electrode is connected to the first type semiconductor layer, and the first conductive electrode, the second conductive electrode, the third conductive electrode and the fourth conductive electrode are separated from each other.

8. The laser element of claim 7, wherein the laser unit further comprises: The first via hole passes through the second type semiconductor layer, the active layer and the first type semiconductor layer, and the first conductive electrode is electrically connected to the positive conductive structure through the first via hole; A first passivation layer is formed on the sidewall of the first through-hole; and The second through hole is located on the side wall of the laser unit and is electrically isolated from the laser unit through the second passivation layer. The conductive layer, the second through hole, the third conductive electrode and the fourth conductive electrode are electrically connected to each other.

9. The laser element of claim 8, wherein the conductive layer is disposed between the bonding layer and the laser unit, and the second via penetrates the laser unit and is electrically connected to the conductive layer.

10. The laser element of claim 9, wherein the conductive layer surrounds the periphery of the light-transmitting substrate.

11. The laser element of claim 8, wherein the bonding layer is disposed between the light-transmitting substrate and the conductive layer and the conductive layer surrounds the laser unit, and the second via penetrates the laser unit and is electrically connected to the conductive layer.

12. The laser element of claim 7, wherein the laser unit further comprises a protective layer disposed on the second type semiconductor layer and opposite to the active layer, and the second conductive electrode portion is connected to the protective layer.

13. The laser element of claim 7, wherein the first conductive electrode and the second conductive electrode are separated from each other and coplanar, and the laser unit further comprises: The first via hole passes through the second type semiconductor layer, the active layer and the first type semiconductor layer, and the first conductive electrode is electrically connected to the positive conductive structure through the first via hole; A first passivation layer is formed on the sidewall of the first through-hole; and The second through hole has its two ends connected to at least one of the conductive layer, the third conductive electrode, and the fourth conductive electrode.

14. The laser element according to any one of claims 7 to 13, wherein the light-transmitting substrate further comprises an optical structure located on one side of the light-transmitting substrate.

15. The laser element of claim 7, wherein the second conductive electrode, the third conductive electrode, and the fourth conductive electrode are separated from each other.

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