EDGE-EMITTING SEMICONDUCTOR LASER DIODE AND METHOD FOR PRODUCING A PLURALITY OF EDGE-EMITTING SEMICONDUCTOR LASER DIODES

Abstract

The invention relates to an edge-emitting semiconductor laser diode, having: —a semiconductor layer sequence, which comprises a bottom surface, a ridge waveguide on a top surface facing away from the bottom surface, and a side surface which is arranged transverse to the top surface, and —a first recess, which extends from the bottom surface to the top surface, wherein —a first region of the semiconductor layer sequence is removed from the side surface in the region of the first recess. The invention further relates to a method for producing a plurality of edge-emitting semiconductor laser diodes.

Claims

1. An edge emitting semiconductor laser diode comprising: a semiconductor layer sequence comprising a bottom surface, a ridge waveguide at a top surface facing away from the bottom surface, and a side surface arranged transversely with respect to the top surface, and a first cutout extending from the bottom surface toward the top surface, wherein a first region of the semiconductor layer sequence is removed from the side surface in the region of the first cutout, in plan view the first cutout does not overlap the ridge waveguide in lateral directions, a filling material is arranged in the first cutout and the filling material comprises a radiation-absorbing material or a radiation-reflecting material.

2. The edge emitting semiconductor laser diode as claimed in claim 1, wherein a side surface of the semiconductor layer sequence that is recessed by the first cutout has a roughened surface.

3. The edge emitting semiconductor laser diode as claimed in claim 1, wherein the first cutout extends in places along a length of the semiconductor laser diode.

4. The edge emitting semiconductor laser diode as claimed in claim 3, wherein the first cutout extends completely along a length of the semiconductor laser diode.

5. The edge emitting semiconductor laser diode as claimed in claim 4, wherein a second cutout extends from the bottom surface toward the top surface of the semiconductor layer sequence, a second region of the semiconductor layer sequence is removed from a front surface in the region of the second cutout, said second region adjoining the first region, and the second cutout extends in places along a width of the semiconductor laser diode.

6. The edge emitting semiconductor laser diode as claimed in claim 5, wherein in plan view the ridge waveguide regionally overlaps the second cutout in lateral directions.

7. The edge emitting semiconductor laser diode as claimed in claim 1, wherein the filling material has a refractive index which is different than a refractive index of the semiconductor layer sequence.

8. The edge emitting semiconductor laser diode as claimed in claim 1, wherein the filling material comprises a conversion material configured to convert laser radiation into electromagnetic secondary radiation of a different wavelength.

9. The edge emitting semiconductor laser diode as claimed in claim 1, wherein there is arranged in the first cutout at least one sensor element configured to detect at least one of the following variables: electromagnetic radiation, electrical resistance, mechanical force, temperature.

10. The edge emitting semiconductor laser diode as claimed in claim 1, wherein a third cutout extends from the bottom surface toward the top surface of the semiconductor layer sequence, and the third cutout is laterally completely surrounded by a material of the semiconductor layer sequence.

11. The edge emitting semiconductor laser diode as claimed in claim 10, wherein in plan view the third cutout overlaps the ridge waveguide.

12. The edge emitting semiconductor laser diode as claimed in claim 1, wherein a further filling material is arranged in the third cutout.

13. A method for producing a plurality of edge emitting semiconductor laser diodes comprising: providing a semiconductor wafer comprising a bottom surface and a plurality of ridge waveguides at a top surface facing away from the bottom surface, producing a plurality of first cutouts extending from the bottom surface toward the top surface, singulating the semiconductor wafer to form semiconductor laser diodes through the first cutouts, wherein in plan view the first cutouts do not overlap the ridge waveguides in lateral directions, a filling material is arranged in the first cutouts, and the filling material comprises a radiation-absorbing material or a radiation-reflecting material.

14. The method as claimed claim 13, wherein the first cutouts are produced by means of one of the following processes: laser scribing, sawing, plasma etching, photoelectrochemical etching.

15. An edge emitting semiconductor laser diode produced by the method of claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In the figures:

[0082] FIGS. 1 and 2 show schematic illustrations of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0083] FIG. 3 shows a schematic illustration of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0084] FIGS. 4 and 5 show schematic illustrations of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0085] FIG. 6 shows a schematic illustration of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0086] FIG. 7 shows a schematic illustration of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0087] FIG. 8 shows a schematic illustration of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0088] FIGS. 9, 10, 11, 12, 13 and 14 show illustrations in plan view in each case of one exemplary embodiment of an edge emitting semiconductor laser diode described here,

[0089] FIGS. 15 and 16 show illustrations in each case of one exemplary embodiment of an edge emitting semiconductor laser diode described here, and

[0090] FIG. 17 shows a schematic illustration of a method step of one exemplary embodiment of a method described here for producing a plurality of edge emitting semiconductor laser diodes.

DETAILED DESCRIPTION

[0091] Elements that are identical, of identical type or act identically are provided with the same reference signs in the figures. The figures and the size relationships of the elements illustrated in the figures among one another should not be regarded as to scale. Rather, individual elements may be illustrated with exaggerated size in order to enable better illustration and/or in order to afford a better understanding.

[0092] Schematic illustrations of an edge emitting semiconductor laser diode 1 in accordance with one exemplary embodiment are illustrated in accordance with FIGS. 1 and 2.

[0093] In accordance with FIG. 1, a side view of the edge emitting semiconductor laser diode 1 comprising a semiconductor layer sequence 2 is illustrated. The semiconductor layer sequence 2 comprises a bottom surface 2a, a ridge waveguide 3 at a top surface 2b facing away from the bottom surface 2a, and a side surface 2c arranged transversely with respect to the top surface 2b.

[0094] Furthermore, a first cutout 4 is arranged in the semiconductor layer sequence 2. The first cutout 4 extends from the bottom surface 2a toward the top surface 2b of the semiconductor layer sequence 2. The first cutout 4 only partly penetrates through the semiconductor layer sequence 2 from the bottom surface to the recessed top surface of the semiconductor layer sequence 2e.

[0095] The first cutout 4 extends completely along a length of the semiconductor laser diode 1a. The first cutout 4 extends in lateral directions completely from a rear side surface 2g, situated opposite the front surface 2d, to the front surface of the semiconductor layer sequence 2d. Furthermore, a filling material 9 is arranged in the first cutout 4 and completely fills the first cutout 4.

[0096] A front view of the edge emitting semiconductor laser diode 1 is illustrated in association with the exemplary embodiment in FIG. 2.

[0097] The ridge waveguide 3 is formed by a ridge-shaped elevated region of the semiconductor layer sequence 2. The ridge waveguide 3 protrudes as a projection from a recessed top surface of the semiconductor layer sequence 2e. The ridge waveguide 3 has a top surface 3a and side surfaces 3b adjoining the latter. The top surface of the semiconductor layer sequence 2b is formed by the recessed top surface of the semiconductor layer sequence 2e, the side surfaces of the ridge waveguide 3b and the top surface of the ridge waveguide 3a.

[0098] A first region of the semiconductor layer sequence 5 is removed from the side surface 2c in the region of the first cutout 5. The first cutout 4 thus exposes a recessed side surface of the semiconductor layer sequence 6. Furthermore, the first region of the semiconductor layer sequence 5 is removed from the front surface 2d in the region of the first cutout 4. The first cutout 4 thus exposes a recessed bottom surface of the semiconductor layer sequence 2f. The side surface of the semiconductor layer sequence 2c, the recessed bottom surface of the semiconductor layer sequence 2f, the recessed side surface of the semiconductor layer sequence 6 and the bottom surface of the semiconductor layer sequence 2a form a step profile.

[0099] In accordance with this exemplary embodiment, the first cutout 4 is completely filled with the filling material 9. A bottom surface of the filling material 9a terminates in planar fashion with the bottom surface of the semiconductor layer sequence 2a. Furthermore, a side surface of the filling material 9b that faces away from the recessed side surface of the semiconductor layer sequence 6 terminates in planar fashion with the side surface of the semiconductor layer sequence 2c.

[0100] The schematic sectional illustration in FIG. 3 shows one exemplary embodiment of an edge emitting semiconductor laser diode 1 described here. In contrast to the exemplary embodiment in FIGS. 1 and 2, no filling material 9 is arranged in a first cutout 4. That is to say that the first cutout is free of the filling material 9. A side surface of the semiconductor layer sequence 6 that is recessed by the first cutout 4 has a roughened surface. The roughened surface is configured for example to scatter electromagnetic radiation, in particular visible light. Advantageously, the front surface 2d can thus be controlled particularly well.

[0101] Furthermore, a longitudinal direction 14 is identified by an arrow in FIG. 3. In this case, the ridge waveguide 3 extends in the longitudinal direction from a rear side surface 2g to a front surface 2d.

[0102] Schematic illustrations of an edge emitting semiconductor laser diode 1 in accordance with one exemplary embodiment are illustrated in accordance with FIGS. 4 and 5.

[0103] As illustrated in FIG. 4, in contrast to the exemplary embodiment in FIG. 1, the first cutout 4 extends in places along a length of the semiconductor laser diode 1a. The first cutout 4 here has a length that is less than the length of the semiconductor laser diode 1a. In this exemplary embodiment, the first cutout 4 does not directly adjoin the rear side surface 2g and the front surface 2d of the semiconductor layer sequence 2. That is to say that the first cutout 4 is arranged in a manner spaced apart from the rear side surface 2g and the front surface 2d of the semiconductor layer sequence 2 in the longitudinal direction 14.

[0104] In contrast to the exemplary embodiment in FIG. 2, the first cutout 4 in accordance with the exemplary embodiment in FIG. 5 does not expose a recessed front surface of the semiconductor layer sequence 2 since the first cutout 4 is arranged in a manner spaced apart from the front surface 2d in the longitudinal direction 14.

[0105] A front view of the edge emitting semiconductor laser diode 1 is illustrated in accordance with the exemplary embodiment in FIG. 6. In contrast to the exemplary embodiment in FIG. 2, the edge emitting semiconductor laser diode 1 comprises a second cutout 7, which partly penetrates through the semiconductor layer sequence 2 from the bottom surface 2a to the top surface 2b of the semiconductor layer sequence.

[0106] A second region of the semiconductor layer sequence 8 is removed from the front surface 2d in the region of the second cutout 7. The second region of the semiconductor layer sequence 8 directly adjoins the first region of the semiconductor layer sequence 5. The second cutout 7 exposes a recessed front surface of the semiconductor layer sequence 2 (not shown here).

[0107] The exemplary embodiment in FIG. 6 shows a front view of the edge emitting semiconductor laser diode 1. In contrast to the exemplary embodiment in FIG. 2, the first cutout 4 penetrates completely through the semiconductor layer sequence 2 from the bottom surface 2a to the recessed top surface 2e of the semiconductor layer sequence 2.

[0108] The edge emitting semiconductor laser diode 1 emits laser radiation from a facet 15. The facet 15 is formed by a part of the front surface 2d of the semiconductor layer sequence 2. Advantageously, the second cutout 7 penetrates only partly through the semiconductor layer sequence 2 at the front surface 2d, such that the facet 15 cannot be damaged by the cutout.

[0109] A side view of the edge emitting semiconductor laser diode 1 is illustrated in accordance with the exemplary embodiment in FIG. 8. As illustrated in FIG. 8, the first cutout 4, in first sectors 16, penetrates partly through the semiconductor layer sequence 2 from the bottom surface 2a to the recessed top surface 2e.

[0110] Furthermore, the first cutout 4, in second sectors 17, penetrates completely through the semiconductor layer sequence 2 from the bottom surface 2a to the recessed top surface 2e. The first sectors 16 and the second sectors 17 directly adjoin one another and are arranged alternately in a manner alternating along the length of the edge emitting semiconductor laser diode 1a.

[0111] A plan view of a bottom surface of the edge emitting semiconductor laser diode 1 is illustrated in each case in accordance with the exemplary embodiments in FIGS. 9 to 14.

[0112] The exemplary embodiment in FIG. 9 together with the exemplary embodiments in FIGS. 1 and 2 forms a common exemplary embodiment. The first cutout 4 extends from the rear side surface 2g to the front side surface.

[0113] In contrast to the exemplary embodiment in FIG. 9, the edge emitting semiconductor laser diode 1 in accordance with FIG. 10 comprises a third cutout 11. The third cutout 11 extends from the bottom surface 2a toward the top surface 2b of the semiconductor layer sequence 2. The third cutout 11 penetrates only partly through the semiconductor layer sequence 2 and does not penetrate through an active layer of the semiconductor layer sequence 2.

[0114] The third cutout 11 here has a quadrilateral shape. A maximum extent in the longitudinal direction 14 of the third cutout 11 is less than the length of the semiconductor laser diode. Furthermore, the third cutout 11 is spaced apart from the first cutout 4 in lateral directions.

[0115] A further filling material 12 is arranged in the third cutout 11 and completely fills the third cutouts 11. Furthermore, the third cutout 11 is laterally completely surrounded by a material of the semiconductor layer sequence 2.

[0116] In contrast to the exemplary embodiment in FIG. 10, three third cutouts 11 are arranged in the semiconductor layer sequence 2, as illustrated in FIG. 11. The third cutouts 11 each have a round shape and are arranged in a manner spaced apart from one another in lateral directions. Furthermore, the third cutouts 11 are arranged with equidistant spacings along the longitudinal directions.

[0117] In contrast to the exemplary embodiment in FIG. 11, two third cutouts 11 are arranged in the semiconductor layer sequence 2, as illustrated in FIG. 12. The third cutouts 11 each have a quadrilateral shape.

[0118] In accordance with the exemplary embodiment in FIG. 13, the third cutouts 11 extend parallel to the longitudinal direction 14. The third cutouts 11 extend completely along a length of the semiconductor laser diode 1a.

[0119] Furthermore, a plurality of third cutouts 11 embodied as strips in each case are arranged in the semiconductor layer sequence 2, as illustrated in FIG. 14. A DFB laser can advantageously be realized by means of the plurality of third cutouts 11 filled with the further filling material 12.

[0120] A side view of the edge emitting semiconductor laser diode 1 is illustrated in accordance with the exemplary embodiment in FIG. 15. Here, in contrast to the exemplary embodiment in FIG. 1, a sensor element 10 is arranged in the first cutout 4. By way of example, an electrical resistance can be detected by means of the sensor element 10.

[0121] The sensor element 10 comprises n-doped silicon, for example. An electrical voltage dropped across the n-doped silicon can then be tapped off by means of a voltage measuring device 20 and the electrical resistance can thus be detected.

[0122] In contrast to the exemplary embodiment in FIG. 15, a plurality of sensor elements 10 are arranged in the first cutout 4, as shown in FIG. 16. The sensor elements 10 are arranged next to one another in lateral directions in the first cutout 4. Bottom surfaces of the sensor elements 10a lie in a common plane with the bottom surface of the semiconductor layer sequence 2a. A side surface of the outermost sensor element 10b facing away from the recessed side surface of the semiconductor layer sequence terminates in planar fashion with the side surface of the semiconductor layer sequence 2c. Besides the sensor elements 10, a filling material 9 is arranged in the cutout.

[0123] By way of example, the first two sensor elements 10 facing away from the recessed side surface of the semiconductor layer sequence comprise n-doped silicon and p-doped silicon, for example. The two sensor elements 10 form a semiconductor detector chip, for example, which can detect electromagnetic radiation by means of a measuring device 20. Furthermore, the sensor element 10 facing the recessed side surface of the semiconductor layer sequence is a piezo-element. The mechanical force can be detected by the piezo-element, for example.

[0124] In accordance with this exemplary embodiment, the piezo-element and the semiconductor detector chip are separated from one another in an electrically insulating manner by the filling material 9.

[0125] A schematic illustration of a method step of one exemplary embodiment of a method described here for producing a plurality of edge emitting semiconductor laser diodes is illustrated in plan view in accordance with FIG. 17.

[0126] Firstly, a semiconductor wafer 13 is provided, comprising a bottom surface 13a and a plurality of ridge waveguides 3 at a top surface 13b facing away from the bottom surface 13a.

[0127] In this method step, a plurality of first cutouts 4 are produced proceeding from the bottom surface of the semiconductor wafer 13a. The first cutouts 4 extend from the bottom surface 13a toward the top surface 13b. Dimensions in lateral directions of the semiconductor laser diodes 1 to be produced are illustrated by way of example using dashed lines on the bottom surface of the semiconductor wafer 13a.

[0128] The semiconductor wafer 13 is subsequently singulated to form semiconductor laser diodes 1 through the first cutouts (not shown here).

[0129] The features and exemplary embodiments described in association with the figures can be combined with one another in accordance with further exemplary embodiments, even though not all combinations are explicitly described. Furthermore, the exemplary embodiments described in association with the figures can alternatively or additionally have further features in accordance with the description in the general part.

[0130] The invention is not restricted to the exemplary embodiments by the description on the basis thereof. Rather, the invention encompasses any novel feature and also any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments.