Laser bar chip and method of manufacturing the same

Abstract

The laser bar chip includes at least a first laser diode and a second laser diode, each of which has a waveguide structure, and a first cathode contact portion conductively connected to the first laser diode and a second cathode contact portion conductively connected to the second laser diode.

Description

[Technical Field]

[0001] The present invention relates to a laser bar chip and a method for manufacturing the laser bar chip. [Background technology]

[0002] Laser bar chips having multiple laser diodes are known in the prior art, in which the laser diodes have a common cathode. Summary of the Invention [Problem to be solved by the invention]

[0003] The object of the present invention is to provide a laser bar chip. A further object of the present invention is to provide a method for manufacturing a laser bar chip. These objects are achieved by a laser bar chip and a method for manufacturing a laser bar chip with the features of the independent claims. Various further configurations are set forth in the dependent claims. [Means for solving the problem]

[0004] The laser bar chip includes at least a first laser diode and a second laser diode, each of which has a waveguide structure, and a first cathode contact portion conductively connected to the first laser diode and a second cathode contact portion conductively connected to the second laser diode.

[0005] In this laser bar chip, the first and second laser diodes can be controlled independently of each other via the first and second cathode contacts. An n-channel FET can be used to switch the current flow through the laser diodes via the cathode contacts. This advantageously allows for very fast switching. N-channel FETs can be made smaller than comparable p-channel FETs, which may allow for smaller design dimensions.

[0006] In one embodiment of the laser bar chip, the laser bar chip has a third laser diode, and the second cathode contact is conductively connected to the third laser diode. This advantageously allows the laser bar chip to be formed with a greater number of laser diodes than the number of cathode contacts. This allows the laser bar chip to be advantageously formed with a large number of laser diodes while maintaining the required minimum size of the cathode contact.

[0007] In one embodiment of the laser bar chip, the laser bar chip has a first anode contact portion conductively connected to the first laser diode, thereby allowing voltage and current to be supplied to the first laser diode via the first anode contact portion and the first cathode contact portion.

[0008] In one embodiment of the laser bar chip, the first anode contact is conductively connected to the second laser diode. This advantageously requires only one anode contact to supply the first and second laser diodes, allowing the laser bar chip to be formed with compact dimensions while maintaining a minimum size for the first anode contact. While the first anode contact is shared by the first and second laser diodes, the first and second cathode contacts allow for individual control of the first and second laser diodes.

[0009] In one embodiment of the laser bar chip, the laser bar chip has a second anode contact conductively connected to the third laser diode, thereby allowing the second laser diode and the third laser diode to be controlled independently of each other even when the second cathode contact is conductively connected to the second laser diode and the third laser diode.

[0010] In one embodiment of the laser bar chip, a non-conductive passivation is arranged on the waveguide structure of the first laser diode. The passivation has an opening in the area of ​​the first anode contact, so that the first anode contact is electrically connected to the first laser diode. The second anode contact is electrically insulated from the first laser diode by the passivation. This advantageously allows the first and second anode contacts to be arranged on the surface of the laser bar chip with a flexible, pre-configurable shape, while still ensuring individual contacting of the individual laser diodes by the individual anode contacts.

[0011] In one embodiment of the laser bar chip, the first anode contact is disposed on a first surface of the laser bar chip, and the first and second cathode contacts are disposed on a second surface of the laser bar chip, which advantageously utilizes available space on the first and second surfaces of the laser bar chip, thereby allowing the laser bar chip to be formed with a minimum overall size when the anode and cathode contacts are maximized.

[0012] In one embodiment of the laser bar chip, a redistribution structure is formed on the second surface of the laser bar chip. This redistribution structure allows for even more flexibility in the configuration of the cathode contacts. Furthermore, the redistribution structure allows for rewiring and integration of the individual cathode contacts.

[0013] In one embodiment of the laser bar chip, the first anode contact, the first cathode contact, and the second cathode contact are arranged together on a first surface of the laser bar chip, which advantageously allows for complete electrical contacting of the laser bar chip via the first surface.

[0014] In one embodiment of the laser bar chip, a rewiring structure is formed on the first surface of the laser bar chip. This rewiring structure can allow for even more flexibility in the shape of the electrical contact surfaces disposed on the first surface. The rewiring structure can also enable rewiring and electrical integration of the individual electrical contact surfaces.

[0015] In one embodiment of the laser bar chip, the epitaxial layer of the laser bar chip has a non-conductive interruption between the first and second laser diodes, thereby achieving decoupling of the first and second laser diodes on the cathode side.

[0016] In one embodiment of the laser bar chip, the epitaxial layer is disposed on a conductive substrate, with a first portion of the substrate and a second portion of the substrate electrically isolated from each other by a non-conductive region. The first cathode contact is conductively connected to the first laser diode through the first portion of the substrate. The second cathode contact is conductively connected to the second laser diode through the second portion of the substrate. The division of the substrate into the first and second portions allows for decoupling of the first and second laser diodes on the cathode side and for separate contacting of the first and second laser diodes on the cathode side.

[0017] In another embodiment of the laser bar chip, the epitaxial layer is disposed on a non-conductive substrate. The substrate has a conductive first via and a conductive second via. The first cathode contact is conductively connected to the first laser diode through the first via. The second cathode contact is conductively connected to the second laser diode through the second via. The first and second vias thereby enable separate contacting of the first and second laser diodes of the laser bar chip on the cathode side.

[0018] A method for manufacturing a laser bar chip includes the steps of: providing a substrate having an epitaxial layer disposed on an upper surface thereof; forming at least a first laser diode and a second laser diode in the epitaxial layer, each of the first laser diode and the second laser diode having a waveguide structure; and forming a first cathode contact portion conductively connected to the first laser diode and a second cathode contact portion conductively connected to the second laser diode.

[0019] This method can be used to manufacture a laser bar chip having at least two laser diodes that are controlled independently of each other, preferably via individual cathode contacts, and can advantageously use n-channel FETs for control, thereby enabling high-speed control.

[0020] In one embodiment of the method, the method comprises the further step of fabricating a non-conductive interruption in the epitaxial layer between the first and second laser diodes, thereby advantageously achieving decoupling of the first and second laser diodes on the cathode side.

[0021] In one embodiment of the method, the substrate is non-conductive. The method then includes the further step of providing a first conductive via and a second conductive via in the substrate. The first cathode contact is conductively connected to the first laser diode through the first via. The second cathode contact is conductively connected to the second laser diode through the second via. The provided vias thus enable separate contact connection of the first laser diode and the second laser diode on the cathode side.

[0022] In one embodiment of the method, the substrate is electrically conductive. The method then includes the further step of providing a non-conductive region in the substrate to electrically isolate the first and second portions of the substrate from each other. The first cathode contact is electrically conductively connected to the first laser diode through the first portion of the substrate. The second cathode contact is electrically conductively connected to the second laser diode through the second portion of the substrate. In this variation of the method, dividing the substrate into the first and second portions allows for separate contacting of the first and second laser diodes on the cathode side.

[0023] In one embodiment of the method, the non-conductive interruptions in the epitaxial layer and the non-conductive regions in the substrate are fabricated together by a FIB process (Focused Ion Beam Irradiation), which advantageously allows for precise formation of the non-conductive interruptions in the epitaxial layer and the non-conductive regions in the substrate.

[0024] In one embodiment of the method, the non-conductive interruptions are fabricated by etching trenches in the epitaxial layer. This method advantageously allows for reliable and accurate formation of the non-conductive interruptions in the epitaxial layer.

[0025] In one embodiment of the method, the grooves are filled with a non-conductive material, whereby advantageously the grooves filled with the non-conductive material can be subsequently filled with further material.

[0026] The above-mentioned properties, features and advantages of the present invention, as well as the manner in which the above-mentioned properties, features and advantages of the present invention are achieved, will become more apparent and will be more clearly understood in connection with the following description of the embodiments which are set forth in more detail in connection with the drawings. [Brief explanation of the drawings]

[0027] [Figure 1] 2 is a schematic diagram of a first surface of a laser bar chip having a plurality of anode contacts. FIG. [Figure 2] 1 is a schematic diagram of a second surface of a laser bar chip having multiple cathode contacts. FIG. [Figure 3] FIG. 10 is a schematic cross-sectional side view of a modified example of the laser bar chip. [Figure 4] FIG. 1 is a schematic, partially transparent perspective view of this modified example of a laser bar chip. [Figure 5] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. [Figure 6] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. [Figure 7] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. [Figure 8] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. [Figure 9] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. [Figure 10] FIG. 10 is a schematic cross-sectional side view of a further modified laser bar chip. DETAILED DESCRIPTION OF THE INVENTION

[0028] Figure 1 shows a schematic perspective view of a first surface 101 of a laser bar chip 100. Figure 2 shows a schematic perspective view of a second surface 102 of the laser bar chip 100, which is on the opposite side to the first surface 101.

[0029] The laser bar chip 100 has a rectangular parallelepiped basic form with a length 110 and a width 120. The length 110 may be, for example, 600 μm and may be predetermined by, for example, the minimum length of the waveguide structure of the laser diode of the laser bar chip 100. The width 120 of the laser bar chip 100 may be, for example, 125 μm.

[0030] The laser bar chip 100 has a plurality of integrated laser diodes 500. In the example shown in Figures 1 and 2, the laser bar chip 100 has a first laser diode 500, 510, a second laser diode 500, 520, a third laser diode 500, 530, a fourth laser diode 500, 540, a fifth laser diode 500, 550, a sixth laser diode 500, 560, a seventh laser diode 500, 570, and an eighth laser diode 500, 580, which are arranged next to each other in this order. However, the laser bar chip 100 may be formed with other numbers of laser diodes 500.

[0031] Each laser diode 500 has a waveguide structure 600, which may be referred to as a ridge. Therefore, the laser bar chip 100 may also be referred to as a multi-ridge laser chip. In the illustrated example, the waveguide structures 600 of the laser diodes 500 are oriented parallel to each other and to the edges of the laser bar chip 100, which has a length 110, and are located on the first surface 101 of the laser bar chip 100, although this is not necessarily required. In the illustrated example, the waveguide structures 600 of the laser diodes 500 are not distributed across the entire width 120 of the laser bar chip 100, but are located closer to one side of the laser bar chip 100, although this may be designed differently. At one end of the length of the waveguide structure 600, the laser diodes 500 each have an output facet 610 from which a laser beam is emitted during operation of the respective laser diode 500.

[0032] The first anode contact portion 810, the second anode contact portion 820, the third anode contact portion 830, and the fourth anode contact portion 840 are disposed on the first surface 101 of the laser bar chip 100. Other variations of the laser bar chip 100 may include fewer or more than four anode contact portions 810, 820, 830, and 840. The anode contact portions 810, 820, 830, and 840 are provided for electrical contact with the laser bar chip 100, for example, by bonding or soldering. The anode contact portions 810, 820, 830, and 840 comprise a metal suitable for electrical contact, such as gold. Preferably, the anode contact portions 810, 820, 830, and 840 are formed to be approximately the same size so as to jointly utilize as fully as possible the available space on the first surface 101 of the laser bar chip 100. For example, each of the anode contact portions 810, 820, 830, 840 may have a size of 134 μm×105 μm.

[0033] The first cathode contact portion 710 and the second cathode contact portion 720 are disposed on the second surface 102 of the laser bar chip 100. Other variations of the laser bar chip 100 may have fewer or more than two cathode contact portions 710, 720. The cathode contact portions 710, 720 are also provided for electrical contacting of the laser bar chip 100 and comprise a metal suitable for electrical contacting, such as gold. Preferably, the cathode contact portions 710, 720 have approximately the same size and jointly utilize the available space on the second surface 102 as fully as possible.

[0034] Anode contacts 810, 820, 830, 840 are provided for contacting the anode side of the laser diode 500. Cathode contacts 710, 720 are provided for electrical contacting of the laser diode 500 on the cathode side. Preferably, each laser diode 500 is individually addressable by a combination of the cathode contacts 710, 720 and the anode contacts 810, 820, 830, 840. To this end, for example, the first cathode contact 710 may be electrically connected to the first laser diode 500, 510, the third laser diode 500, 530, the fifth laser diode 500, 550, and the seventh laser diode 500, 570. In this case, the second cathode contact portion 720 is conductively connected to the second laser diode 500,520, the fourth laser diode 500,540, the sixth laser diode 500,560, and the eighth laser diode 500,580. In this case, the first anode contact 810 may be connected to the first laser diode 500, 510 and the second laser diode 500, 520, the second anode contact 820 to the third laser diode 500, 530 and the fourth laser diode 500, 540, the third anode contact 830 to the fifth laser diode 500, 550 and the sixth laser diode 500, 560, and the fourth anode contact 840 to the seventh laser diode 500, 570 and the eighth laser diode 500, 580, although other wiring arrangements are of course also possible.

[0035] The anode contacts 810, 820, 830, 840 may be controlled, for example, via p-channel FETs, and the cathode contacts 710, 720 may be controlled, for example, via n-channel FETs.

[0036] Several variations of laser bar chip 100 are described below, with the description being limited in part to the manner in which each variation of laser bar chip 100 differs from the previous variation of laser bar chip 100. Otherwise, the above description also applies to each of the additional variations of laser bar chip 100.

[0037] 3 shows a schematic cross-sectional side view of a modified example of the laser bar chip 100. In the modified example shown in FIG. 3, the laser bar chip 100 has only a first laser diode 500, 510, a second laser diode 500, 520, a third laser diode 500, 530, a fourth laser diode 500, 540, a fifth laser diode 500, 550, and a sixth laser diode 500, 560. In this case, the first laser diode 500, 510, the second laser diode 500, 520, the third laser diode 500, 530, the fourth laser diode 500, 540, and the fifth laser diode 500, 550 are arranged next to each other in this order, while the sixth laser diode 500, 560 is arranged on the opposite side of the first laser diode 500, 510 from the second laser diode 500, 520. Furthermore, the laser bar chip 100 has a third cathode contact portion 730 in addition to the first cathode contact portion 710 and the second cathode contact portion 720 .

[0038] The laser bar chip 100 includes a conductive substrate 200. The substrate 200 may be formed of, for example, a semiconductor material with conductive n-type doping. An epitaxial layer 400 is disposed on an upper surface 201 of the substrate 200. Within the epitaxial layer 400, a waveguide structure 600 is formed by partially removing the epitaxial layer 400. In a region 240 of each waveguide structure 600, the epitaxial layer 400 includes an active layer 620. In each laser diode 500, the portion of the epitaxial layer 400 facing the substrate 200 forms an n-side cathode on one side of the active layer 620, and the portion of the epitaxial layer 400 facing away from the substrate 200 forms a p-side anode on the other side of the active layer 620.

[0039] At the first surface 101 of the laser bar chip 100, the epitaxial layer 400 and the waveguide structure 600 formed in the epitaxial layer 400 are covered by a non-conductive passivation 410. In the region of the waveguide structure 600 of the laser diode 500, the passivation 410 at least partially comprises an anode opening 420 that allows electrical contacting of the laser diode 500 on the anode side.

[0040] Figure 4 shows a schematic perspective view of the first surface 101 of a variation of the laser bar chip 100 shown in Figure 3. In Figure 4, the anode contacts 810, 820, 830, 840 are shown partially transparent to allow visualization of the waveguide structure 600 of the laser diode 500 and the anode opening 420 in the passivation 410.

[0041] 4 shows that each anode contact 810, 820, 830, 840 partially covers the waveguide structure 600 of all laser diodes 500, which is not visible in FIG. 3. However, the first anode contact 810 is conductively connected only to the first laser diode 500, 510 and the second laser diode 500, 520. The second anode contact 820 is conductively connected only to the third laser diode 500, 530 and the fourth laser diode 500, 540. The third anode contact 830 is conductively connected only to the fifth laser diode 500, 550. The fourth anode contact 840 is conductively connected only to the sixth laser diode 500, 560. This achieves that the passivation 410 has an anode opening 420 in the region between the first laser diode 500, 510 and the first anode contact portion 810 and in the region between the second laser diode 500, 520 and the first anode contact portion 810, while the passivation 410 electrically insulates the first laser diode 500, 510 and the second laser diode 500, 520 from the second anode contact portion 820, the third anode contact portion 830, and the fourth anode contact portion 840, and further the passivation 410 electrically insulates the first anode contact portion 810 from the third laser diode 500, 530, the fourth laser diode 500, 540, the fifth laser diode 500, 550, and the sixth laser diode 500, 560. This also applies correspondingly to the further laser diode 500 and the further anode contacts 810, 820, 830, 840.

[0042] The shapes of the anode contact portions 810, 820, 830, 840 may be selected differently from the shapes in FIG.

[0043] The first laser diodes 500, 510 and the sixth laser diodes 500, 560 are conductively connected to each other on the cathode side through the epitaxial layer 400 and the first portion 210 of the substrate 200. The second laser diodes 500, 520 and the third laser diodes 500, 530 are conductively connected to each other on the cathode side through the epitaxial layer 400 and the second portion 220 of the substrate 200. The fourth laser diodes 500, 540 and the fifth laser diodes 500, 550 are conductively connected to each other on the cathode side through the epitaxial layer 400 and the third portion 230 of the substrate 200.

[0044] In contrast, in the region between the first laser diode 500, 510 and the second laser diode 500, 520, the epitaxial layer 400 has a non-conductive interruption 440. Additionally, the first portion 210 of the substrate 200 is electrically isolated from the second portion 220 of the substrate 200 by the non-conductive region 240. This ensures that the first laser diode 500, 510 and the second laser diode 500, 520 are not conductively connected to each other on the cathode side. Correspondingly, the epitaxial layer 400 also has a non-conductive interruption 440 between the third laser diode 500, 530 and the fourth laser diode 500, 540, and the second portion 220 of the substrate 200 is electrically insulated from the third portion 230 by a further non-conductive region 240, so that the third laser diode 500, 530 and the fourth laser diode 500, 540 are also not conductively connected to each other on the cathode side. Furthermore, in this example of the laser bar chip 100, the fifth laser diode 500, 550 and the sixth laser diode 500, 560 are also not conductively connected to each other on the cathode side.

[0045] The first cathode contact portion 710 is conductively connected to the cathode side of the first laser diode 500, 510 via the first portion 210 of the substrate 200, and is further conductively connected to the cathode side of the sixth laser diode 500, 560. The second cathode contact portion 720 is conductively connected to the cathode side of the second laser diode 500, 520 and the cathode side of the third laser diode 500, 530 via the second portion 220 of the substrate 200. The third cathode contact portion 730 is conductively connected to the cathode side of the fourth laser diode 500, 540 and the cathode side of the fifth laser diode 500, 550 via the third portion 230 of the substrate 200.

[0046] Thus, in the modified laser bar chip 100 shown in FIG. 3, each laser diode 500 can be individually controlled and supplied with voltage and current. The first laser diodes 500, 510 can be controlled via the first anode contact 810 and the first cathode contact 710. The second laser diodes 500, 520 can be controlled via the first anode contact 810 and the second cathode contact 720. The third laser diodes 500, 530 can be controlled via the second anode contact 820 and the second cathode contact 720. The fourth laser diodes 500, 540 can be controlled via the second anode contact 820 and the third cathode contact 730. The fifth laser diodes 500, 550 can be controlled via the third anode contact 830 and the third cathode contact 730. The sixth laser diode 500 , 560 can be controlled via the fourth anode contact 840 and the first cathode contact 710 .

[0047] To manufacture the laser bar chip 100 variant shown in FIG. 3, a substrate 200 is first provided in a known manner, with an epitaxial layer 400 disposed on its upper surface 201. The waveguide structure 600 of the laser diode 500 is then formed in the epitaxial layer 400 in a known manner. For example, before the anode contacts 810, 820, 830, and 840 are formed, a non-conductive interruption 440 can be formed in the epitaxial layer 400 and a non-conductive region 240 can be formed in the substrate 200. This can be done, for example, by a focused ion beam (FIB) process, during which the electrical conductivity of the epitaxial layer 400 and the substrate 200 is eliminated position-dependently by doping breakdown. The non-conductive interruption 440 of the epitaxial layer 400 and the non-conductive region 240 of the substrate 200 can be formed together and simultaneously, preferably simultaneously. Subsequently, anode contacts 810, 820, 830, 840 and cathode contacts 710, 720, 730 may be applied and structured. A passivation 790 may optionally be arranged between the individual cathode contacts 710, 720, 730, as shown in Figure 3. The sequence of the described processing steps may of course be chosen differently.

[0048] FIG. 5 shows a schematic cross-sectional side view of a further variation of the laser bar chip 100. The variation shown in FIG. 5 generally corresponds to the variation shown in FIG. 3 and can be fabricated according to the method described above. However, in the variation shown in FIG. 5, after the cathode contacts 710, 720, and 730 are provided, a redistribution structure 900 is further formed on the second surface 102 of the laser bar chip 100. The redistribution structure 900 includes one or more layers of non-conductive and conductive materials and allows the shape of the cathode contacts 710, 720, and 730 to be reshaped on the second surface 102 of the laser bar chip 100 without causing undesirable short circuits between the individual cathode contacts 710, 720, and 730. The redistribution structure 900 may also be used to properly interconnect the individual cathode contacts 710, 720, and 730.

[0049] In further variations of the laser bar chip 100, a redistribution structure may alternatively or additionally be formed on the first surface 101 of the laser bar chip 100. This redistribution structure may also include layers of non-conductive and conductive materials. This redistribution structure may be provided for the purpose of reshaping the easily fabricated shapes of the anode contacts 810, 820, 830, 840, 850, 860 on the first surface 101 of the laser bar chip 100, or for the purpose of electrically conductively connecting each or all of the anode contacts 810, 820, 830, 840, 850, 860 to each other.

[0050] 6 shows a schematic cross-sectional side view of a further variation of the laser bar chip 100. In this variation of the laser bar chip 100 and all variations of the laser bar chip 100 described below, the first laser diode 500, 510, the second laser diode 500, 520, the third laser diode 500, 530, the fourth laser diode 500, 540, the fifth laser diode 500, 550, and the sixth laser diode 500, 560 are arranged side by side in this order. This variation of the laser bar chip 100 has a fourth cathode contact portion 740, a fifth cathode contact portion 750, and a sixth cathode contact portion 760 in addition to the first cathode contact portion 710, the second cathode contact portion 720, and the third cathode contact portion 730. Cathode contact portions 710, 720, 730, 740, 750, and 760 are also disposed on the second surface 102 of the laser bar chip 100. Furthermore, this modification of the laser bar chip 100 has a fifth anode contact portion 850 and a sixth anode contact portion 860 in addition to the first anode contact portion 810, the second anode contact portion 820, the third anode contact portion 830, and the fourth anode contact portion 840. The anode contact portions 810, 820, 830, 840, 850, and 860 are also disposed on the first surface 101 of the laser bar chip 100.

[0051] In the variation of the laser bar chip 100 shown in FIG. 6, the substrate 200 is formed non-conductively. For example, the substrate 200 may comprise an undoped semiconductor material. A first via 310, a second via 320, a third via 330, a fourth via 340, a fifth via 350, and a sixth via 360 are formed in the substrate 200. The first cathode contact 710 is conductively connected to the cathode side of the first laser diode 500, 510 through the first via 310. The second cathode contact 720 is conductively connected to the cathode side of the second laser diode 500, 520 through the second via 320. The third cathode contact 730 is conductively connected to the cathode side of the third laser diode 500, 530 through the third via 330. The fourth cathode contact portion 740 is conductively connected to the cathode side of the fourth laser diode 500, 540 through the fourth via 340. The fifth cathode contact portion 750 is conductively connected to the cathode side of the fifth laser diode 500, 550 through the fifth via 350. The sixth cathode contact portion 760 is conductively connected to the cathode side of the sixth laser diode 500, 560 through the sixth via 360. Thus, in the laser bar chip 100 variation shown in FIG. 6 , each laser diode 500 is conductively connected to exactly one of the cathode contact portions 710, 720, 730, 740, 750, 760.

[0052] The first anode contact 810 is conductively connected to the anode side of the first laser diode 500, 510 through one of the anode openings 420 in the passivation 410. In turn, the first anode contact 810 is electrically isolated from the remaining laser diodes 500. The second anode contact 820 is conductively connected to the anode side of the second laser diode 500, 520. The third anode contact 830 is conductively connected to the anode side of the third laser diode 500, 530. Correspondingly, further anode contacts 840, 850, 860 are each connected to exactly one of the laser diodes 500, 540, 550, 560. Thus, each of the laser diodes 500 of the laser bar chip 100 variation shown in FIG. 6 has one of the individual cathode contact portions 710, 720, 730, 740, 750, 760 and one of the individual anode contact portions 810, 820, 830, 840, 850, 860.

[0053] In the laser bar chip 100 variation shown in FIG. 6, the epitaxial layer 400 has conductive interruptions 440 between the first laser diode 500, 510 and the second laser diode 500, 520, between the second laser diode 500, 520 and the third laser diode 500, 530, between the third laser diode 500, 530 and the fourth laser diode 500, 540, between the fourth laser diode 500, 540 and the fifth laser diode 500, 550, and between the fifth laser diode 500, 550 and the sixth laser diode 500, 560. Thus, the cathode sides of all the laser diodes 500 are electrically isolated from each other. In this variation of the laser bar chip 100, the non-conductive interruptions 440 are formed as grooves 450 in the epitaxial layer 400.

[0054] To fabricate the laser bar chip 100 variation shown in FIG. 6, a non-conductive substrate 200 having an epitaxial layer 400 disposed on its upper surface 201 is first provided in a known manner. Laser diodes 500 are then formed in the epitaxial layer 400 in a known manner. Anode contacts 810, 820, 830, 840, 850, and 860 may then be formed on the first surface 101 of the laser bar chip 100 in a known manner and conductively connected to the anode side of the laser diodes 500. Non-conductive interruptions 440 may then be provided in the epitaxial layer 400, for example, by etching trenches 450. The trenches 450 may then be selectively filled with a non-conductive material. Alternatively, the non-conductive interruptions 440 may again be provided by FIB methods. Before or after, vias 310, 320, 330, 340, 350, 360 may be provided, for example, by first etching openings starting from second surface 102 into substrate 200 and then filling these openings with a conductive material, for example, gold or copper, for example, by evaporation. Cathode contacts 710, 720, 730, 740, 750, 760 are then formed on second surface 102 of laser bar chip 100 and conductively connected to the cathode side of laser diode 500.

[0055] FIG. 7 shows a schematic cross-sectional side view of a further variation of the laser bar chip 100. The variation shown in FIG. 7 generally corresponds to the variation of the laser bar chip 100 shown in FIG. 6. However, in fabricating the variation shown in FIG. 7, a redistribution structure 900 is further formed on the second surface 102 of the laser bar chip 100 following the fabrication method described above. The redistribution structure 900 may also comprise layers of non-conductive and conductive materials and may be used to reshape the easily fabricated shapes of the cathode contacts 710, 720, 730, 740, 750, 760 on the second surface 102 or to conductively connect each or all of the cathode contacts 710, 720, 730, 740, 750, 760 to each other.

[0056] In further variations of the laser bar chip 100, a redistribution structure may alternatively or additionally be formed on the first surface 101 of the laser bar chip 100. This redistribution structure may also include layers of non-conductive and conductive materials. This redistribution structure may be provided to reshape the easily fabricated shapes of the anode contacts 810, 820, 830, 840, 850, 860 on the first surface 101 of the laser bar chip 100, or to electrically conductively connect each or all of the anode contacts 810, 820, 830, 840, 850, 860 to each other.

[0057] 8 shows a schematic cross-sectional side view of a further variant of the laser bar chip 100. The variant shown in FIG. 8 generally corresponds to the variant of FIG.

[0058] However, the modified laser bar chip 100 shown in Figure 8 has only a first anode contact portion 810. The first anode contact portion 810 is conductively connected to the anode sides of all six laser diodes 500, 510, 520, 530, 540, 550, and 560. However, the cathode side of the laser diode 500 is connected to one of the individual cathode contact portions 710, 720, 730, 740, 750, and 760, as in the modified example of Figure 6. As a result, in the modified laser bar chip 100 shown in Figure 8, each laser diode 500 may be individually controlled.

[0059] The fabrication of the variant of laser bar chip 100 shown in Figure 8 is carried out similarly to the fabrication of the variant shown in Figure 6, except that non-conductive interruptions 440 in epitaxial layer 400 are already created before first anode contact portions 810 are provided, for example by etching grooves 450. Grooves 450 are then filled with non-conductive material 455. First anode contact portions 810 are then formed on first surface 101 of laser bar chip 100.

[0060] In further variations (not shown) of the laser bar chip 100, the laser bar chip 100 is formed as in the variations of FIGS. 6 and 8, but has more than one or fewer than six anode contacts 810, 820, 830, 840, 850, and 860, each of which may be conductively connected to one or more of the laser diodes 500. In these variations, the redistribution structure 900 may be located on the first surface 101 and / or the second surface 102 of the laser bar chip 100. The presence of the redistribution structure 900 on the second surface 102 is also possible in the variation shown in FIG. 8.

[0061] 9 shows a schematic cross-sectional side view of a further variation of the laser bar chip 100. The variation shown in FIG. 9 has only a first cathode contact portion 710, a second cathode contact portion 720, a third cathode contact portion 730, and a fourth cathode contact portion 740. Furthermore, this variation has only a first anode contact portion 810, a second anode contact portion 820, and a third anode contact portion 830.

[0062] In this modification, the first anode contact portion 810 is conductively connected to the anode sides of the first laser diodes 500, 510 and the second laser diodes 500, 520. The second anode contact portion 820 is conductively connected to the anode sides of the third laser diodes 500, 530 and the fourth laser diodes 500, 540. The third anode contact portion 830 is conductively connected to the anode sides of the fifth laser diodes 500, 550 and the sixth laser diodes 500, 560.

[0063] The first cathode contact portion 710 is electrically connected to the cathode side of the first laser diode 500, 510. The second cathode contact portion 720 is electrically connected to the cathode sides of the second laser diode 500, 520 and the third laser diode 500, 530. The third cathode contact portion 730 is electrically connected to the cathode sides of the fourth laser diode 500, 540 and the fifth laser diode 500, 550. The fourth cathode contact portion 740 is electrically connected to the cathode side of the sixth laser diode 500, 560.

[0064] In the laser bar chip 100 variation shown in FIG. 9, the substrate 200 is also formed non-conductively, e.g., as an undoped semiconductor substrate. The epitaxial layer 400 also has a non-conductive interruption 440 between the first laser diode 500, 510 and the second laser diode 500, 520, which electrically isolates the cathode sides of the first laser diode 500, 510 and the second laser diode 500, 520 from each other. Correspondingly, the epitaxial layer 400 also has a non-conductive interruption 440 between the third laser diode 500, 530 and the fourth laser diode 500, 540, as well as between the fifth laser diode 500, 550 and the sixth laser diode 500, 560. The non-conductive interruption 440 may be formed as a groove 450 filled with a non-conductive material 455. Preferably, in fabricating the modified laser bar chip 100 shown in FIG. 9, the non-conductive blocking portion 440 is fabricated before providing the anode contact portions 810, 820, 830.

[0065] 9, anode contacts 810, 820, 830 are also disposed on the first surface 101 of the laser bar chip 100. Additionally, in this variation, cathode contacts 710, 720, 730, 740 are also disposed on the first surface 101 of the laser bar chip 100. To this end, passivation 410 disposed on the epitaxial layer 400 and on the waveguide structure 600 has cathode openings 430 that allow conductive connection between the cathode contacts 710, 720, 730, 740 and the portions of the epitaxial layer 400 connected to the cathode sides of the respective laser diodes 500.

[0066] To fabricate the variation of laser bar chip 100 shown in FIG. 9, a non-conductive substrate 200 having an epitaxial layer 400 disposed on its upper surface 201 is first provided using known methods. Laser diodes 500 having waveguide structures 600 are then fabricated in epitaxial layer 400 using known methods. Even before removing the mask used to fabricate waveguide structures 600, this mask may be used to provide grooves 450 and cathode openings 430. After filling grooves 450 with a non-conductive material 455 to form non-conductive interruptions 440, cathode contacts 710, 720, 730, 740 and anode contacts 810, 820, 830 may be formed on first surface 101 of laser bar chip 100.

[0067] 10 shows a schematic cross-sectional side view of a further modified laser bar chip 100. The modified example shown in FIG. 10 generally corresponds to the modified laser bar chip 100 shown in FIG. 9, except that after providing the cathode contact portions 710, 720, 730, 740 and the anode contact portions 810, 820, 830, a redistribution structure 900 is further fabricated on the first surface 101 of the laser bar chip 100. The redistribution structure 900 may include layers of non-conductive and conductive materials and may be used to modify the easily fabricated shapes of the cathode contact portions 710, 720, 730, 740 and the anode contact portions 810, 820, 830 on the first surface 101 of the laser bar chip 100. The redistribution structure 900 may also be used to electrically connect each or all of the cathode contacts 710, 720, 730, 740 and the anode contacts 810, 820, 830 to each other.

[0068] 9 and 10, as well as any further variations of the laser bar chip 100, may be formed using a number of laser diodes 500 other than the number shown. The number of cathode contacts 710, 720, 730, 740, 750, 760 and the number of anode contacts 810, 820, 830, 840, 850, 860 may also be selected differently than those shown.

[0069] Although the present invention has been described in more detail based on preferred embodiments, the invention is not limited to the disclosed examples, and other variations may occur to those skilled in the art. [Explanation of symbols]

[0070] 100 Laser bar chip 101 First Surface 102 Second Surface 110 length 120 width 200 boards 201 Top surface 210 First Part 220 Second Part 230 Third Part 240 Non-conductive area 310 First Via 320 Second Via 330 Third Via 340 Fourth Via 350 5th Via 360 Sixth Via 400 epitaxial layer 410 Passivation 420 Anode opening 430 cathode opening 440 Non-conductive interrupter 450 Groove 455 Non-conductive materials 500 Semiconductor Laser 510 first laser diode 520 Second Laser Diode 530 Third Laser Diode 540 The Fourth Laser Diode 550 The 5th Laser Diode 560 The 6th Laser Diode 570 The 7th Laser Diode 580 8th Laser Diode 600 waveguide structure 610 Output Facets 620 Active layer 710 first cathode contact portion 720 Second cathode contact part 730 Third cathode contact 740 Fourth cathode contact 750 Fifth cathode contact 760 6th cathode contact part 790 Passivation 810 first anode contact portion 820 second anode contact part 830 Third anode contact part 840 4th anode contact part 850 5th anode contact part 860 6th anode contact part 900 rewiring structure

Claims

1. A laser bar chip (100), The laser bar chip (100) has at least a first laser diode (500, 510) and a second laser diode (500, 520); The first laser diode (500, 510) and the second laser diode (500, 520) each have a waveguide structure (600); The laser bar chip (100) has a first cathode contact portion (710) electrically connected to the first laser diode (500, 510) and a second cathode contact portion (720) electrically connected to the second laser diode (500, 520); The laser bar chip (100) has a first anode contact portion (810) that is conductively connected to the first laser diode (500, 510) and the second laser diode (500, 520). Laser bar chip (100).

2. The laser bar chip (100) has a third laser diode (500, 530), the second cathode contact portion (720) is conductively connected to the third laser diode (500, 530); The laser bar chip (100) of claim 1.

3. The laser bar chip (100) has a second anode contact portion (820) that is conductively connected to the third laser diode (500, 530). The laser bar chip (100) of claim 2.

4. a non-conductive passivation (410) disposed on the waveguide structure (600) of the first laser diode (500, 510); the passivation (410) has an opening in the area of ​​the first anode contact portion (810), so that the first anode contact portion (810) is conductively connected to the first laser diode (500, 510); the second anode contact (820) is electrically isolated from the first laser diode (500, 510) by the passivation (410); The laser bar chip (100) of claim 3.

5. the first anode contact (810) is disposed on a first surface (101) of the laser bar chip (100); the first cathode contact portion (710) and the second cathode contact portion (720) are disposed on a second surface (102) of the laser bar chip (100); A laser bar chip (100) according to any one of claims 1 to 4.

6. a redistribution structure (900) formed on the second surface (102) of the laser bar chip (100); The laser bar chip (100) of claim 5.

7. the first anode contact portion (810), the first cathode contact portion (710), and the second cathode contact portion (720) are disposed together on a first surface (101) of the laser bar chip (100); A laser bar chip (100) according to any one of claims 1 to 6.

8. A rewiring structure (900) is formed on the first surface (101) of the laser bar chip (100). A laser bar chip (100) according to any one of claims 5 to 7.

9. The epitaxial layer (400) of the laser bar chip (100) has a non-conductive interruption (440) between the first laser diode (500, 510) and the second laser diode (500, 520). A laser bar chip (100) according to any one of claims 1 to 8.

10. The epitaxial layer (400) is disposed on a conductive substrate (200); the first portion (210) of the substrate (200) and the second portion (220) of the substrate (200) are electrically isolated from each other by a non-conductive region (240); the first cathode contact portion (710) is conductively connected to the first laser diode (500, 510) through the first portion (210) of the substrate (200), and the second cathode contact portion (720) is conductively connected to the second laser diode (500, 520) through the second portion (220) of the substrate (200); The laser bar chip (100) of claim 9.

11. The epitaxial layer (400) is disposed on a non-conductive substrate (200); The substrate (200) has a conductive first via (310) and a conductive second via (320); the first cathode contact portion (710) is conductively connected to the first laser diode (500, 510) through the first via (310), and the second cathode contact portion (720) is conductively connected to the second laser diode (500, 520) through the second via (320); The laser bar chip (100) of claim 9.

12. - providing a substrate (200) having an epitaxial layer (400) disposed on its upper surface (201); - forming at least a first laser diode (500, 510) and a second laser diode (500, 520) in said epitaxial layer (400), said first laser diode (500, 510) and said second laser diode (500, 520) each having a waveguide structure (600); - forming a first cathode contact (710) electrically connected to the first laser diode (500, 510) and a second cathode contact (720) electrically connected to the second laser diode (500, 520); - forming a first anode contact (810) electrically connected to the first laser diode (500, 510) and to the second laser diode (500, 520); Including, A method for manufacturing a laser bar chip (100).

13. - a further step of fabricating a non-conductive interruption (440) in said epitaxial layer (400) between said first laser diode (500, 510) and said second laser diode (500, 520), Including, The method of claim 12.

14. The substrate (200) is non-conductive; The method comprises: - the further step of providing a first conductive via (310) and a second conductive via (320) in said substrate (200); Including, the first cathode contact portion (710) is conductively connected to the first laser diode (500, 510) through the first via (310), and the second cathode contact portion (720) is conductively connected to the second laser diode (500, 520) through the second via (320); The method of claim 13.

15. The substrate (200) is conductive; The method comprises: - the further step of providing a non-conductive region (240) in said substrate (200) to electrically isolate a first portion (210) of said substrate (200) and a second portion (220) of said substrate (200) from each other; Including, the first cathode contact portion (710) is conductively connected to the first laser diode (500, 510) through the first portion (210) of the substrate (200), and the second cathode contact portion (720) is conductively connected to the second laser diode (500, 520) through the second portion (220) of the substrate (200); The method of claim 13.

16. The non-conductive interruption (440) in the epitaxial layer (400) and the non-conductive region (240) in the substrate (200) are fabricated together by a FIB process.

16. The method of claim 15.

17. The non-conductive interruption (440) is fabricated by etching a trench (450) in the epitaxial layer (400).

16. The method of claim 13 or 15.

18. The groove (450) is filled with a non-conductive material (455).

18. The method of claim 17.

Images