Patent Publication Number: US-2021167581-A1

Title: Optoelectronic component

Description:
TECHNICAL FIELD 
     This disclosure relates to an optoelectronic component. 
     BACKGROUND 
     Optoelectronic components, for example, in the form of laser diodes are known. US 2009/0137098 A1 and U.S. Pat. No. 7,724,793 B2 disclose a layer structure comprising an active zone that generates electromagnetic radiation. A ridge structure is arranged on the layer structure, the ridge structure being arranged between two side faces arranged parallel to one another. 
     There is nonetheless a need to provide an improved optoelectronic component. 
     SUMMARY 
     We provide an optoelectronic component including a layer structure including an active zone that generates electromagnetic radiation, wherein the active zone is arranged in a plane, the layer structure includes a top side and four side faces, the first and third side faces are arranged opposite one another, the second and fourth side faces are arranged opposite one another, a strip-type ridge structure is arranged on the top side of the layer structure, the ridge structure extends between the first side face and the third side face, the first side face constitutes an emission face for electromagnetic radiation, a first recess is introduced into the top side of the layer structure laterally alongside the ridge structure, a second recess is introduced into the first recess, the second recess extends as far as the second side face, the first recess extends over an entire length of the laser diode from the first side face as far as the third side face along the second side face, the first recess extends as far as the second side face, the second recess is introduced into a first base face of the first recess, the second recess extends along the second side face, the second recess is configured at a distance from the first side face and at a distance from the third side face, and the second recess leads into the second side face. 
     We also provide an optoelectronic component including a layer structure including an active zone that generates electromagnetic radiation, wherein the active zone is arranged in a plane, the layer structure includes a top side and four side faces, the first and third side faces are arranged opposite one another, the second and fourth side faces are arranged opposite one another, a strip-type ridge structure is arranged on the top side of the layer structure, the ridge structure extends between the first side face and the third side face, the first side face constitutes an emission face for electromagnetic radiation, a first recess is introduced into the top side of the layer structure laterally alongside the ridge structure, a second recess is introduced into the first recess, the second recess extends as far as the second side face, the first recess extends over an entire length of the laser diode from the first side face as far as the third side face along the second side face, in the region of the first recess, the second side face includes laterally recessed wall faces, the second recess is introduced laterally into the first recess and into the recessed wall faces of the second side face, the second recess is introduced into the top side of the layer structure, the second recess extends along the second side face, and the second recess is configured at a distance from the first side face and at a distance from the third side face. 
     We further provide an optoelectronic component including a layer structure including an active zone that generates electromagnetic radiation and is arranged in a plane, wherein the layer structure includes a top side and four side faces, first and third side faces are arranged opposite one another, second and fourth side faces are arranged opposite one another, a strip-shaped ridge structure is arranged on the top side of the layer structure and extends between the first side face and the third side face, the first side face constitutes an emission face for electromagnetic radiation, wherein a first recess is introduced into the top side of the layer structure laterally alongside the ridge structure, a second recess is introduced into the first recess, the second recess extends as far as the second side face, and at least one third recess is introduced into a base face of the first recess laterally alongside the ridge structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic perspective illustration of an optoelectronic component. 
         FIG. 2  shows a cross section through a laser diode including two recesses. 
         FIG. 3  shows a cross section through a laser diode including three recesses. 
         FIG. 4  shows a schematic plan view of a top side of the laser diode. 
         FIG. 5  shows a schematic cross section through a laser diode including a chamfered recess. 
         FIG. 6  shows a schematic cross section through a further example of a laser diode including a recess which is configured partly perpendicularly and partly in a chamfered fashion. 
         FIG. 7  shows a schematic cross section through a further example of a laser diode including a plurality of third recesses. 
         FIG. 8  shows a cross section through a further example of a laser diode including a partly perpendicular and partly chamfered sidewall. 
         FIG. 9  shows a schematic perspective illustration of a further example of a laser diode including a recess at the second sidewall. 
         FIG. 10  shows a schematic perspective illustration of a further example of a laser diode including a recess on the third side face. 
         FIG. 11  shows a schematic perspective illustration of a laser diode including a recess on the third side face and on the first side face. 
         FIG. 12  shows a schematic plan view of a part of a wafer including components according to  FIG. 9  before the components are singulated. 
         FIG. 13  shows a schematic plan view of a part of a wafer with a further example of components before the components are singulated. 
         FIG. 14  shows a schematic plan view of a part of a wafer including components according to  FIG. 10  before the components are singulated. 
         FIG. 15  shows a schematic plan view of a part of a wafer including components according to  FIG. 11  before the components are singulated. 
     
    
    
     LIST OF REFERENCE SIGNS 
     
         
           1  Laser diode 
           2  Layer structure 
           3  First side face 
           4  Second side face 
           5  Third side face 
           6  Fourth side face 
           7  Top side 
           8  Ridge structure 
           9  Active Zone 
           10  Laser mode 
           11  First recess 
           12  Second recess 
           13  First base face 
           14  Second base face 
           15  Breaking direction 
           16  Third recess 
           17  Third base face 
           18  Wall face 
           19  Angle 
           20  Edge 
           21  Upper section 
           22  Lower section 
           23  First wall face 
           24  Second base face 
           25  Second wall face 
           26  Fourth recess 
           27  Fifth recess 
           28  Length 
           31  Seventh recess 
           32  Seventh base face 
           33  Seventh wall face 
           34  Further seventh wall face 
           35  Distance 
           36  Carrier 
           37  Center plane 
           40  Dislocation 
           41  2 nd  Dislocation 
           42  3 rd  Dislocation 
           44  Passivation layer 
           45  Wall face 
           46  1 st  Further wall face 
           47  2 nd  Further wall face 
           48  3 rd  Further wall face 
           49  Depth 
           50  Further sixth wall face 
           51  Further sixth wall face 
           52  First separating line 
           53  Second separating line 
           54  Wafer 
       
    
     DETAILED DESCRIPTION 
     Our optoelectronic component comprises a layer structure comprising an active zone that generates electromagnetic radiation, wherein the layer structure comprises a top side and four side faces, a strip-type ridge structure is arranged on the top side of the layer structure, the ridge structure extends between the first side face and the third side face, the first side face constitutes an emission face for electromagnetic radiation, a first recess is introduced into the top side of the layer structure laterally alongside the ridge structure, a second recess is introduced into the first recess, and the second recess extends as far as the second side face. As a result, formation of dislocations in the event of the breaking of the first and/or the third side face is largely avoided. Moreover, in p-down mounting, a leakage current flowing via the side face is reduced. 
     The first recess may be introduced into the first side face and/or into the third side face, wherein the second recess is introduced into the first side face and/or into the third side face. A further reduction in formation of dislocations in the event of the breaking of the first and/or the third side face may be achieved as a result of the arrangement of the first and/or the third recess in the region of the first and/or the third side face. 
     At least one third recess may be introduced into a base face of the first recess laterally alongside the ridge structure. A further reduction in formation of dislocations in the event of the breaking of the first and/or the third side face may be achieved as a result. 
     The third recess may be introduced into the first and/or into the third side face. A further reduction in formation of dislocations in the event of the breaking of the first and/or the third side face is achieved as a result. 
     The third recess may be arranged substantially parallel to the second side face, wherein the third recess is arranged at a distance from the first side face and at a distance from the third side face. 
     The first recess may extend along a longitudinal direction of the second side face, wherein the first recess is arranged at a distance from the first side face and at a distance from the third side face. 
     The first recess may extend over a range of 1% to 99% of a longitudinal side of the second side face. A further reduction in leakage currents flowing via the second side face in p-down mounting is achieved in this way. 
     The second recess may extend along a longitudinal direction of the second side face, wherein the second recess is arranged at a distance from the first side face and at a distance from the third side face. 
     The second recess may extend over a range of 1% to 99%, in particular of 50% to 95%, of a longitudinal side of the first side face. A further reduction in leakage currents flowing via the second side face in p-down mounting is achieved in this way. 
     The second recess may comprise a greater depth relative to a base face of the first recess than the third recess. 
     The second recess may comprise a depth of 0.5 μm to 50 μm, in particular 1 μm to 10 μm, relative to the top side. A sufficient reduction in leakage currents flowing via the second side face in p-down mounting is reduced in this way. 
     The second recess may comprise a depth of 2 μm to 6 μm relative to the top side. 
     The second and fourth side faces may be configured mirror-symmetrically with respect to a center plane, wherein the top sides arranged on opposite sides relative to the ridge structure are configured mirror-symmetrically with respect to the center plane. Leakage currents via the second and third side faces are thus reduced. Furthermore, formation of dislocations at the first and/or at the third side face is reduced further. 
     At least walls and/or base faces of the first recess and/or of the second recess and/or of the third recess may be covered with a passivation layer. Leakage currents via the side faces may be reduced as a result. 
     The first recess may extend over an entire length of the laser diode from the first as far as the third side face along the second side face, wherein the first recess extends as far as the second side face, the second recess is introduced into a first base face of the first recess, the second recess extends along the second side face, the second recess is configured at a distance from the first side face and at a distance from the third side face, and the second recess leads into the second side face. 
     The first recess may extend over an entire length of the laser diode from the first as far as the third side face along the second side face, wherein in the region of the first recess the second side face comprises laterally recessed wall faces, the second recess is introduced laterally into the first recess and into the recessed wall faces, the second recess is introduced into the top side of the layer structure, the second recess extends along the second side face, and the second recess is configured at a distance from the first side face and at a distance from the third side face. 
     A further recess may be introduced into the first side face and into the top side of the layer structure, wherein the further recess is arranged between the ridge structure and the recessed wall face of the second side face. 
     The further recess may comprise a base face, wherein the base face is arranged between the top side of the layer structure and a level of the second base face of the second recess. 
     A second further recess may be introduced into the third side face and into the top side of the layer structure, wherein the second further recess is arranged between the ridge structure and the recessed wall face of the second side face. 
     The second further recess may comprise a base face, wherein the base face is arranged between the top side of the layer structure and a level of the second base face of the second recess. 
     The second base face of the second recess may be arranged at the same level as a base face of the first recess. 
     The above-described properties, features and advantages and the way in which they are achieved will become clearer and more clearly understood in association with the following description of the examples explained in greater detail in association with the drawings. 
       FIG. 1  shows, in a schematic illustration, an optoelectronic component in the form of a laser diode  1  comprising a layer structure  2 . The layer structure  2  comprises four side faces  3 ,  4 ,  5 ,  6 . In general, the first side face  3  and the third side face  5  are arranged parallel to one another. Likewise, in general, the second side face  4  and the fourth side face  6  are arranged parallel to one another. A strip-type ridge structure  8  is arranged on a top side  7  of the layer structure  2 . The ridge structure  8  extends in a longitudinal direction between the first and third side faces  3 ,  5 . At the first side face  3 , an emission face  7  is provided below the ridge structure  8 , via which emission face electromagnetic radiation is emitted on the first side face  3 . 
     In a coordinate system comprising an x-axis, a y-axis and a z-axis, which are each perpendicular to one another, the first and third side faces  3 ,  5  are arranged perpendicularly to the z-axis. The second and fourth side faces  4 ,  6  are arranged perpendicularly to the x-axis. The top side  7  is arranged perpendicularly to the y-axis. In the example illustrated, the ridge structure  8  is arranged centrally with respect to a width along the x-axis of the top side  7 . The ridge structure covers only a part of the width of the top side  7 . The ridge structure  8  extends along the z-axis perpendicularly to the first side face  3  from the first side face  3  as far as the third side face  5 . Depending on the example chosen, the ridge structure  8  may also end before the plane of the first and/or the third side face  3 ,  5  or be aligned at an angle of not equal to 90° with respect to the plane of the first and/or the third side face  3 ,  5 . The first and third side faces may comprise mirror layers. Moreover, an insulation layer may be arranged on the top side  7 . 
     The optoelectronic component is configured, for example, as an edge emitting laser diode or as a light-emitting diode (LED). In particular, the laser diode/LED may be produced from a III-V semiconductor material, in particular from indium gallium nitride. The layer structure  2  comprises an active zone  9 , which is arranged perpendicularly to the y-axis in a plane and may extend laterally along the x-axis beyond the width of the ridge structure. On account of the ridge structure  8 , a guidance of a generated laser mode  10  below the ridge structure  8  in the active zone  9  is achieved. The layer structure  2  may consist of a III-V semiconductor material and be arranged on a carrier. The substrate and/or the layer structure  2  may be based on a III-V compound semiconductor or a II-VI compound semiconductor or zinc oxide. The II-VI compound semiconductor may be a sulfide or a selenide. The III-V compound semiconductor may be based on a nitride compound semiconductor, a phosphide compound semiconductor, an antimonite compound semiconductor or an arsenide compound semiconductor. The III-V compound semiconductor may be, for example, a nitride such as for instance, gallium nitride, indium nitride or aluminum nitride, a phosphide such as for instance, gallium phosphide or indium phosphide a first arsenide such as for instance, gallium arsenide or indium arsenide. In this case, by way of example, the material system Al n In 1−n−m Ga m N may be provided, wherein 0≤n≤1, 0≤m≤1 and n+m≤1. Moreover, the material system may comprise AlnGamIni-n-mP, wherein 0≤n≤1, 0≤m≤1 and n+m≤1. Moreover, the material system may comprise Al n Ga m In 1−n−m Sb, wherein 0≤n≤1, 0≤m≤1 and n+m≤1. 
     During production of the laser diode  1 , individual laser diodes  1  are detached from an assemblage, in particular from a wafer, wherein in particular the first and third side faces  3 ,  5  are produced with the aid of a process of breaking the wafer. The first and third side faces  3 ,  5  should satisfy conditions stipulated for a good quality of the laser diode  1 , in particular constitute a planar face without disturbances and dislocations. Therefore, breaking the first and third side faces  3 ,  5  is an important process for the quality of the laser diode  1 . 
     Hereinafter, various structures are presented which make possible a process of breaking the first and third side faces  3 ,  5 , wherein a high quality of the first and third side faces  3 ,  5  is produced. 
       FIG. 2  shows a schematic partial cross section through an arrangement comprising a first example of a laser diode  1  in the X-Y plane, which is secured to a carrier  36  by the ridge structure  8  using p-down mounting. The carrier  36  may be configured in the form of a semiconductor substrate. The active zone  9  is arranged in the layer structure  2 , wherein with the aid of the ridge structure  8 , during operation of the laser diode  1 , a laser mode  10  are generated below the ridge structure  8 . The laser mode  10  is reflected by the third side face  5  and is at least partly emitted via the first side face  3 . 
     The layer structure  2  comprises a first recess  11  between the ridge structure  8  and the second side face  4  in the top side  7 , the first recess extending in the x-axis in the direction of the second side face  4  as far as a second recess  12 . The first recess  11  comprises a first base face  13  and extends in the longitudinal direction, that is to say along the z-axis, for example, from the first side face  3  as far as the third side face  5 . The first recess  11  may also extend only over a part of the length of the component. 
     The first base face  13  and side faces  45  of the first recess  11  may be provided with an electrically insulating passivation layer  44 . The passivation layer  44  is configured as an oxide layer, for example, and may be produced before the laser diodes are singulated, for example, in an oxidation method using oxygen plasma or water vapor at elevated temperatures. The first base face  13  and the side face  45  of the first recess  11  are constructed from silicon, for example, such that the passivation layer may be formed from silicon oxide. Moreover, the passivation layer may also be formed from SiN x , TiO 2  or Ta 2 O 5 . 
     The second recess  12  extends from the first base face  13  of the first recess  11  via a wall face  18  along the y-axis as far as a second base face  14 . The wall face  18  and the second base face  14  may likewise be covered by the passivation layer  44 . The second recess  12  may extend in the z-axis from the first side face  3  as far as the third side face  5 . Moreover, the second recess  12  may extend along the z-axis only over a part of the length of the laser diode. 
     The first base face  13  is arranged along the y-axis, for example, in the region of the plane in which the active zone  9  is arranged. In the event of breaking, the layer structure  2  configured as a semiconductor layer structure is broken in a breaking direction  15  from left to right perpendicularly to the z-axis. On account of the first and second recesses  11 ,  12  in this case transverse facets and/or disturbances at the first side face  3  are avoided or diverted into a region below the laser mode  10 . Moreover, the second and/or the fourth side face  4 ,  6  may likewise be produced by breaking methods or sawing methods or etching methods. 
     A dislocation  40  is illustrated schematically, the dislocation proceeding from the wall face  18  of the second recess  12  and extending along the x-axis transversely over the width of the laser diode  1 . However, the dislocation  40  is arranged below the laser mode  10  and thus cannot impair the quality of the electromagnetic radiation emitted by the laser diode  1 . 
     The top side  7  may be configured mirror-symmetrically with respect to a center plane  37  on both sides of the ridge structure  8 . The center plane  37  is arranged parallel to the y-z plane and centrally in the x-direction in the ridge structure  8 . The fourth side face  6  may likewise be configured mirror-symmetrically with respect to the center plane  37 . Consequently, the fourth side face  6  is provided with corresponding recesses  11 ,  12  in accordance with the second side face  4 . 
       FIG. 3  shows a schematic partial cross section of a further example of a laser diode  1  in the x-y plane, wherein a third recess  16  is provided in addition to the first and second recesses  11 ,  12 . The third recess  16  is introduced into the base face  13  of the first recess  11  along the x-axis between the ridge structure  8  and the second recess  12 . The third recess  16  may comprise a smaller depth than the second recess  12 . Likewise, a third base face  17  of the third recess  16  may be arranged at least in the region of the plane of the active zone  9  or below the plane of the active zone  9 . The third recess  16  may extend over the entire length in the z-direction of the laser diode  1  or only over a partial section. Moreover, side faces and the third base face  17  of the third recess  16  may be covered with a passivation layer  44 . With the aid of the third recess  16 , a further improvement in the quality of the first side face  3  may be achieved in the event of the breaking of the layer structure  2  in the breaking direction  15  from left to right. 
     With the aid of the third recess  16 , transverse facets or disturbances which arise in a deeper region and are produced during breaking may likewise be curbed. A dislocation  40  is illustrated schematically, the dislocation proceeding from the second recess  12  and extending along the x-axis transversely over the width of the laser diode. However, the dislocation  40  is arranged below the laser mode  10  and thus cannot impair the quality of the laser radiation. Moreover, a second dislocation  41  is illustrated, which proceeds from the second recess  12  and extends along the x-axis transversely as far as the third recess  16 . The third recess  16  prevents the further formation of the second dislocation  41  in the direction of a region of the laser mode  10 . 
     The first, second and/or third recess  11 ,  12 ,  16  may be arranged only in the region of the first and third side faces  3 ,  5  and may not extend over the entire length of the laser diode in the z-axis. In a further example, the first, the second and/or the third recess  11 ,  12 ,  16 , depending on the example chosen, may be arranged in the region of the first and third side faces  3 ,  5  and may extend over the entire length of the laser diode  1  along the z-axis. In a further example, the first, the second and/or the third recess  11 ,  12 ,  16  may be arranged only in the region of the first and third side faces  3 ,  5 . 
       FIG. 4  shows a view of the example from  FIG. 3  in a schematic view from above, wherein the first, second and third recesses  11 ,  12 ,  16  are configured in a manner only adjoining the first and third side faces  3 ,  5 . The first, second and third recesses  11 ,  12 ,  16  may also extend over the entire length along the z-axis of the layer structure  2 . The top side  7  and the second and fourth side faces  4 ,  6  are configured mirror-symmetrically with respect to the center plane  37 . The passivation layer is not explicitly illustrated. 
       FIG. 5  shows a schematic partial cross section in the x-y plane through a further example of a laser diode  1 , wherein, in a manner adjoining the second side face  4 , a second recess  12  is introduced into the top side  7  of the layer structure  2 . The second recess  12  comprises a wall face  18  arranged at an inclination. The wall face  18  may be aligned at an angle  19  of between 91° and 179° relative to the y-axis. In particular, the wall face  18  may be arranged at an angle  19  with respect to the y-axis of 135° to 155°. The second recess  12  may have a depth of 0.5 to 50 μm relative to the top side  7 . In particular, the depth of the recess  12  may be 1 to 10 μm, in particular 2 to 6 μm. In this example of the second recess  12 , the depth is considered to be a level of an edge  20  on the y-axis at which the wall face  18  transitions into the second side face  4 . The edge  20  is aligned along the z-axis. Since dislocations  40  preferably proceed perpendicularly to faces, it is possible to divert disturbances and transverse facets downward by a chamfered second side face  4 , as illustrated schematically. The top side  7  and the wall face  18  may be covered with a passivation layer  44 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  in relation to the center plane  37 . 
       FIG. 6  shows a partial cross section through a further example of a laser diode  1  in the y-x plane comprising a second recess  12 , which comprises a first wall face  23  at the second side face  4  in an upper section  21 , the first wall face being arranged parallel to the y-axis. The first wall face  23  transitions into a second base face  14 . The second base face  14  does not extend as far as the second side face  4  in the x-axis, but rather transitions into a second wall face  25  in a lower section  22 . 
     The second wall face  25  is configured in the form of an inclined face that is at an angle  19  relative to the y-axis that may be 91° to 179°, in particular 135° to 155°. Consequently, in this example, a lower section  22  of the second recess  12  is arranged at an inclination with respect to the y-axis. Consequently, dislocations  40  or transverse facets produced in the lower region, in particular, may be diverted into deeper regions. The top side  7  and/or the first wall face and/or the second wall face and/or the second base face  14  may be covered with a passivation layer  44 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  in relation to the center plane  37 . 
       FIG. 7  shows a partial cross section through a further example of a laser diode  1  in the y-x plane that substantially corresponds to the example from  FIG. 3 , wherein, however, a fourth and a fifth recess  26 ,  27  are additionally introduced into the first base face  13  of the first recess  11 . The fifth recess  27  may be dispensed with or a plurality of recesses may also be provided. The fourth and fifth recesses  26 ,  27  may be configured in accordance with the third recess  16 . Providing the fourth and fifth recesses  26 ,  27  makes it possible to curb further transverse facets  41  arising between the third recess  16  and the fourth recess and/or between the fourth and fifth recesses  26 ,  27 . The depths of the third recess  16  and of the fourth and fifth recesses  26 ,  27  may be different. Moreover, the wall faces of the third recess  16  and of the fourth and fifth recesses  26 ,  27  may also be arranged at an inclination with respect to the y-axis, as was explained on the basis of the examples in  FIGS. 5 and 6 . 
     The top side  7  and/or the wall face  18  of the second recess  12  and/or the second base face  14  of the second recess  12  and/or the walls and base faces of the third and/or the fourth and/or the fifth recess  16 ,  26 ,  27  may be covered with a passivation layer  44 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  relative to the center plane  37 . Furthermore, the top side  7  arranged between the ridge structure  8  and the fourth side face  6  may also comprise a third, a fourth and a fifth recess and may be configured mirror-symmetrically with respect to the center plane  37 . 
       FIG. 8  shows a partial cross section through a further example of a laser diode  1  in the y-x plane comprising a second recess  12 . The second recess  12  comprises a first wall face  23  in an upper section  21 , the first wall face being arranged at an angle  19  at an inclination with respect to the y-axis. The angle  19  may be 91° to 179°, in particular 135° to 155°. The first wall face  23  transitions via an edge  20  into a lower section  22  and a second wall face  25 . The edge  20  is made parallel to the z-axis in particular over the entire length of the laser diode  1 . The second wall face  25  is arranged parallel to the y-axis. The second wall face  25  transitions via a second base face  14  into the second side face  4  in the direction of the x-axis. Consequently, in this example, by the first wall face  23  arranged at an inclination, disturbances and transverse facets  40  that may arise during breaking are diverted downward outside the region of the laser mode  10 . The top side  7  and/or the first and/or the second wall face  23 ,  25  and/or the second base face  14  of the second recess  12  may be covered with a passivation layer  44 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  relative to the center plane  37 . 
       FIG. 9  shows, in a schematic perspective illustration, a partial section of a further example of a laser diode  1  with a view of the first side face  3 , wherein a first recess  11  comprising a first base face  13  is configured in the top side  7 . The first recess  11  extends in the z-direction, for example, over the entire length of the laser diode  1  or only over a part of the entire length of the laser diode  1 . Consequently, the first recess  11  may be configured in the form of a stepped gradation. The first recess  11  comprises a first wall face  45  and a first base face  13 . The first wall face  45  may be arranged perpendicularly to the top side  7 . The first base face  13  may be arranged parallel to the top side  7 . The wall face  45  and/or the first base face  13  may be covered with a passivation layer  44 . 
     A second recess  12  is introduced into the first base face  13  of the first recess  11 . The second recess  12  extends in the x-direction as far as the second side face  4 . Consequently, the second recess  12  is opened in the first base face  13  and in the second side face  4 . The second recess  12  comprises three further wall faces  46 ,  47 ,  48  and a second base face  14 . The second base face  14  is arranged, e.g., parallel to the first base face  13 . The first wall face  46  is arranged in a manner offset inward relative to the third side face  5 . The first wall face  46  may be arranged parallel to the third side face  5 . The third wall face  48  is arranged in a manner offset inward relative to the first side face  3 . The third wall face  48  may be arranged parallel to the first side face  3 . The three further wall faces  46 ,  47 ,  48  and the second base face  14  may be covered with a thin passivation layer  44 , which changes the shape of the second recess  12  only insignificantly. The second recess  12  is arranged between the first and third side faces  3 ,  5  and at a distance from the first and third side faces  3 ,  5  in the example illustrated. The first and third side faces  3 ,  5  constitute facet faces. 
     The second recess  12  may also extend as far as the first and third side faces  3 ,  5  and may be configured in the form of a second stepped gradation. Moreover, the second recess  12  may also be arranged only in the region of the first and third side faces  3 ,  5 . In this example, the first recess  11 , proceeding from the top side  7 , comprises a depth parallel to the Y-axis of 0.5 to 25 μm. The second recess  12  comprises a depth  49  with respect to the first base face  13  of the first recess  11  which is in the range of 0.5 μm to 50 μm, for example, 1 μm to 10 μm, in particular 2 μm to 6 μm. The first base face  13  may be arranged above or below the active zone  9 . 
     The length  28  of the second recess  12  parallel to the z-axis may extend 5% to 100% of the entire length of the laser diode  1  parallel to the z-axis. In the case of a length of 100%, the second recess  12  comprises only one second further wall face  47  and a second base face  14 . In particular, the length  28  of the second recess may extend 50% to 99% of the length of the laser diode  1  parallel to the z-axis. Moreover, the length  28  of the second recess  12  may extend 80% to 97% along the z-axis of the laser diode. The second recess  12  may be arranged symmetrically and centrally with respect to the length of the laser diode in the z-direction. With the aid of these examples, it is possible to reduce leakage currents in the case of p-down mounting, in which the ridge structure  8  is mounted on a carrier, on account of the first and second recesses  11 ,  12  and/or the passivation layer  44 . Moreover, dislocations in the event of the breaking of the first and/or the third side face  3 ,  5  are reduced as a result the recesses  11 ,  12 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  relative to the center plane  37 . 
       FIG. 10  shows a perspective partial illustration of a further example of a laser diode  1  with a view of the first side face  3 . A first recess  11  is introduced into the top side  7 , the first recess directly adjoining the second side face  4  and extending from the first side face as far as the third side face  3 ,  5 . The first recess  11  comprises a first base face  13 , which is arranged, e.g., parallel to the top side  7 . Moreover, the first recess  11  is delimited by two further sixth wall faces  50 ,  51 . The two further sixth wall faces  50 ,  51  additionally constitute inwardly recessed parts of the second side face  4 . Consequently, the first recess  11  forms a lateral stepped gradation of the first side face  4 . 
     A second recess  12  is introduced into the top side  7  and into the first recess  11 . A boundary between the first recess  11  and the second recess  12  is illustrated in a dashed manner on the first base face  13 . Moreover, the second recess  12  adjoins the further wall faces  50 ,  51  of the second side face  4 . The second recess  12  comprises three further wall faces  46 ,  47 ,  48  and a second base face  14 . The second recess  12  is arranged between the first and third side faces  3 ,  5  and at a distance from the first and third side faces  3 ,  5 . In this example, the first recess  11  and the second recess  12  comprise the same depth along the Y-axis. The second recess  12  comprises a depth with respect to the top side  7  which is 0.5 μm to 50 μm, for example, 1 μm to 10 μm, in particular 2 μm to 6 μm. 
     The length  28  of the second recess  12  parallel to the z-axis may extend 5% to 100% of the entire length of the laser diode  1  parallel to the z-axis. The second recess  12  may be arranged centrally with respect to the longitudinal extent of the laser diode  1 . In a length of 100%, the second recess  12  comprises only one second further wall face  47  and a second base face  14 . In particular, the length  28  of the second recess  12  may extend 50% to 99% of the length of the laser diode  1  parallel to the z-axis. Moreover, the length  28  of the second recess  12  may extend 80% to 97% along the z-axis of the laser diode. With the aid of these examples, it is possible to reduce leakage currents in the case of p-down mounting, in which the ridge structure  8  is mounted on a carrier, on account of the first and second recesses  11 ,  12  and/or the passivation layer  44 . Moreover, dislocations in the event of the breaking of the first and/or the third side face  3 ,  5  are reduced as a result the recesses  11 ,  12 . Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  relative to the center plane  37  and may comprise a corresponding first and second recess  11 ,  12 . The first and second recesses  11 ,  12  of the fourth side  6  may also comprise different shapes or dimensions than the first and second recesses  11 ,  12  of the second side  4 . 
     The three further wall faces  46 ,  47 ,  48  and the second base face  14  of the second recess  12  and the first base face  13  and the further sixth wall faces  50 ,  51  may be covered with a passivation layer  44 . 
     An at least partly passivated second side face  4  having laterally different widths, e.g., is thinner in the region of the first and third side faces, enables a combination with a deep mesa structure with additional recesses in the region of the first and third side faces  3 ,  5 , even if the active zone  9  is situated very close to a side face of the layer structure and is, for example, at a distance of less than 50 μm in an asymmetrical ridge position. As a result, it is possible to reduce leakage currents in p-down mounting, in which the ridge structure  8  is mounted on a carrier. Moreover, transverse facets and/or disturbances may be curbed. Moreover, the fourth side face  6  of the laser diode  1  may be configured mirror-symmetrically with respect to the second side face  4  relative to the center plane  37 . 
       FIG. 11  shows a partial illustration of one example of a laser diode  1  with a view of the first side face  3 , which substantially corresponds to the example from  FIG. 10 . In this case, however, a seventh recess  31  is additionally provided, which is introduced into the top side  7  of the layer structure  2  in the region of the first side face  3 . The seventh recess  31  comprises a seventh base face  32 . The seventh base face  32  is arranged between the top side  7  and the second base face  14  of the second recess  12 . Moreover, the seventh recess  31  extends in the x-axis right into a region in which the second recess  12  is also formed in an offset manner laterally in the z-axis. The seventh recess  31  additionally affords the possibility of curbing transverse facets and disturbances in the event of the breaking of the laser diode  1  or in the event of the breaking of the first side face  3 . A seventh recess  31  as in the first side face  3  may also be arranged on the third side face  5 . 
     The second recess  12  with the wall face  18  is at a distance from the ridge structure  8  which is the same or smaller or larger compared to the seventh recess  31  with a seventh wall face  33  facing the ridge structure  8  or is aligned parallel to the z-axis. Moreover, the seventh recess  31  comprises a further seventh wall face  34  situated opposite the seventh wall face  33 . The further seventh wall face  34  is at a greater distance from the ridge structure  8  than the wall face  18  of the second recess  12 . The second and seventh recesses  12 ,  31  are at a distance  35  from one another in the z-direction. The faces of the seventh recess  31  may be covered with a passivation layer  44 . 
     On the top side  7  of the laser diode  1 , an insulation layer is applied on both sides of the ridge structure  8  such that a current flow to the region of the ridge structure  8  is limited. Moreover, the second and fourth side faces  4 ,  6  and also the recesses are covered with a passivation layer  44 . The three further wall faces  46 ,  47 ,  48  and the second base face  14  of the second recess  12  and the first base face  13  and the further sixth wall faces  50 ,  51  may be covered with a passivation layer  44 . The passivation layer  44  is produced, e.g., with the aid of a chemical conversion, in particular by an oxidation of the material of the side faces. The side faces  4 ,  6  are composed of silicon, for example, wherein the passivation layer consists of silicon oxide. 
       FIG. 12  shows a schematic plan view of a part of a wafer  54  comprising components in accordance with  FIG. 9  before the components are singulated. In this case, first separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8 . The second separating lines  53  run perpendicularly to the ridge structures  8 . 
     The first recesses  11  are configured as parallel strips. The second recesses  12  are configured as strips arranged in parallel lines. First separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8  through the middle of the first and second recesses  11 ,  12 . The second separating lines  53  each run perpendicularly to the ridge structures  8  between two second recesses  12 . The second separating lines  53  define the first and third side faces of a component. The first separating lines  52  define the second and fourth side faces of the components. The components are singulated in accordance with the separating lines  52 ,  53 . In this case, the wafer  54  is broken along the second separating lines  53 . The wafer  54  may likewise be broken along the first separating lines  52 . In the example illustrated, the first recess  11  extends over an entire length of a component. The second recess  12  extends only over a part of the length of a component. 
       FIG. 13  shows a schematic plan view of a part of a wafer  54  comprising a further example of components before the components are singulated. In this case, first separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8 . The second separating lines  53  run perpendicularly to the ridge structures  8 . 
     The first recesses  11  are configured as parallel strips. The second recesses  12  are configured as parallel strips. First separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8  through the middle of the second recesses  12 . The second separating lines  53  each run perpendicularly to the ridge structures  8  between two second recesses  12 . 
     The second separating lines  53  define the first and third side faces of a component. The first separating lines  52  define the second and fourth side faces of the components. The components are singulated in accordance with the separating lines  52 ,  53 . In this case, the wafer  54  is broken along the second separating lines  53 . The wafer  54  may likewise be broken along the first separating lines  52 . The components are configured substantially in accordance with  FIG. 12 , wherein in this example, however, the second recesses  12  extend over the entire length of the components. 
       FIG. 14  shows a schematic plan view of a part of a wafer  54  comprising components in accordance with  FIG. 10  before the components are singulated. The ridge structures  8  are arranged parallel to one another. 
     The first recesses  11  are configured as parallel strips. The second recesses  12  are configured as strips arranged in parallel lines. First separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8  through the middle of the first recesses  11 . The second separating lines  53  run perpendicularly to the ridge structures  8  in each case between two second recesses  12 . 
     The second separating lines  53  define the first and third side faces of a component. The first separating lines  52  define the second and fourth side faces of the components. The components are singulated in accordance with the separating lines  52 ,  53 . In this case, the wafer  54  is broken along the second separating lines  53 . The wafer  54  may likewise be broken along the first separating lines  52 . The first recesses  11  extend over the entire length of the components. The second recesses  12  extend only over a part of the length of the components. 
       FIG. 15  shows a schematic plan view of a part of a wafer  54  comprising components in accordance with  FIG. 11  before the components are singulated. The arrangement is as in  FIG. 14 , wherein seventh recesses  31  are additionally provided as well. The ridge structures  8  are arranged parallel to one another. In this case, first separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first recesses  11  are configured as parallel strips. The second recesses  12  are configured as strips arranged in parallel lines. First separating lines  52  and second separating lines  53  are illustrated as dashed lines. The first separating lines  52  run parallel to the strip-type ridge structures  8  through the middle of the first recesses  11 . The second separating lines  53  run perpendicularly to the ridge structures  8  in each case between two second recesses  12  and centrally through seventh recesses  31 . 
     The second separating lines  53  define the first and third side faces of a component. The first separating lines  52  define the second and fourth side faces of the components. The components are singulated in accordance with the separating lines  52 ,  53 . In this case, the wafer  54  is broken along the second separating lines  53 . The wafer  54  may likewise be broken along the first separating lines  52 . The seventh recesses  31  are arranged on the second separating lines  53 . 
     Although our components have been more specifically illustrated and described in detail by preferred examples, this disclosure is not restricted by the examples disclosed and other variations may be derived therefrom by those skilled in the art, without departing from the scope of protection of the appended claims. 
     This application claims priority of DE 10 2015 116 712.3, the subject matter of which is incorporated herein by reference.