EP3841619A1

EP3841619A1 - Optoelectronic semiconductor component having a semiconductor contact layer and method for producing the optoelectronic semiconductor component

Info

Publication number: EP3841619A1
Application number: EP19758911.2A
Authority: EP
Inventors: Mohammad Tollabi Mazraehno; Mariel Grace Jama; Hans-Jürgen LUGAUER; Alexander Pfeuffer
Original assignee: Osram Oled GmbH
Current assignee: Osram Oled GmbH
Priority date: 2018-08-22
Filing date: 2019-08-09
Publication date: 2021-06-30
Also published as: CN112585769A; JP2021534590A; KR20210034073A; DE102018120490A1; US20210288221A1; US11764330B2; WO2020038743A1

Abstract

An optoelectronic semiconductor component (10) comprises a first semiconductor layer (120) of a first conductivity type, a second semiconductor layer (130) of a second conductivity type, respective semiconductor materials of the first and second semiconductor layers (120, 130) each being a compound semiconductor material containing a first, a second and a third composition element, and a second contact region (135) for electrically contacting the second semiconductor layer (130). The second contact region (135) has a second metal contact layer (134) and a semiconductor contact layer (132) between the metal contact layer (134) and the second semiconductor layer (130). A semiconductor material of the semiconductor contact layer (132) contains the first, second and third composition elements, the concentration of the first and second composition elements changing from a position on a side of the second semiconductor layer (130) to a position on the side of the second metal contact layer (134).

Description

OPTOELECTRONIC SEMICONDUCTOR COMPONENT WITH ONE

SEMICONDUCTOR CONTACT LAYER AND METHOD FOR PRODUCING THE OPTOELECTRONIC SEMICONDUCTOR COMPONENT

BACKGROUND

This patent application claims the priority of German patent application DE 10 2018 120 490.6, the disclosure content of which is hereby incorporated by reference.

A light emitting diode (LED) is a light emitting device based on semiconductor materials. For example, an LED includes a pn junction. If electrons and holes recombine with one another in the region of the pn junction, for example because a corresponding voltage is applied, electromagnetic radiation is generated.

Generally, new concepts are sought with which the efficiency of the components, i.e. the ratio of output optical power and electrical power supplied can be increased.

The present invention has for its object to provide an improved optoelectronic semiconductor component.

According to the present invention, the object is achieved by the subject matter and the method of the independent claims. Advantageous further developments are defined in the dependent patent claims.

SUMMARY According to embodiments, an optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, wherein a semiconductor material of the first and second semiconductor layer is in each case a compound semiconductor material which contains a first, a second and a third composition element, and a second contact area for electrically contacting the second semiconductor layer. The second contact area has a second metallic contact layer and a semiconductor contact layer between the second metallic contact layer and the second semiconductor layer. A semiconductor material of the semiconductor contact layer contains the first, second and third composition element, wherein the concentration of the first and second composition element changes from a position on one side of the second semiconductor layer to a position on the side of the second metallic contact layer.

For example, the first semiconductor layer is arranged and structured over the first semiconductor layer. The second contact region can be arranged between structured regions of the first semiconductor layer. The first semiconductor layer can be structured such that it is removed from parts of the second semiconductor layer.

The optoelectronic semiconductor component can furthermore have a semiconductor connection layer between the semiconductor contact layer and the second metallic contact layer, the semiconductor connection layer containing two from the group of the first, second and third composition elements. For example, the semiconductor connection layer may contain only two from the group of the first, second and third composition elements. According to embodiments, a concentration of a composition element can the semiconductor contact layer in a region from the second semiconductor layer to the second metallic contact layer.

For example, a band gap of a material of the semiconductor connection layer can be smaller than a band gap of the second semiconductor layer.

According to refinements, the first semiconductor layer can contain the same composition elements as the second semiconductor layer. The Zusammenset _Z ungsverhältnis the Zusammenset wetting elements in the first and second semiconductor layer may be the same or different.

According to embodiments, the first semiconductor layer can contain a plurality of sublayers made of the same composition elements, the doping level or composition ratio of the composition elements differing in at least two sublayers.

The composition elements of the second semiconductor layer can each be selected from the group consisting of In, Al, Ga, B and N. For example, the composition elements of the second semiconductor layer can each contain Al, Ga and N. Furthermore, the second semiconductor layer can additionally contain In. According to further embodiments, the composition elements of the second semiconductor layer can each contain In, Ga and N. Alternatively, the composition elements of the second semiconductor layer each contain Al, B and N or contain Ga, B and N.

A method for producing an optoelectronic semiconductor component comprises structuring a first semiconductor layer of a first conductivity type, which A second semiconductor layer of a second conductivity type is arranged such that the first semiconductor layer is removed from parts of the second semiconductor layer and structured regions of the first semiconductor layer are formed, wherein a semiconductor material of the first and second semiconductor layer is a compound semiconductor material, which is a contains first, a second and a third composition element. The method further comprises forming a semiconductor contact layer and a second metallic contact layer between the structured regions of the first semiconductor layer, a second contact region being formed for the electrical contacting of the second semiconductor layer. The semiconductor contact layer is formed between a second metallic contact layer and a second semiconductor layer. A semiconductor material of the semiconductor contact layer contains the first, second and third composition element, wherein a concentration of the first and second composition element changes from a position on one side of the second semiconductor layer to a position on the side of the second metallic contact layer.

The semiconductor contact layer can be formed by selective epitaxial growth over exposed areas of the second semiconductor layer. The method may further include forming a semiconductor connection layer between the semiconductor contact layer and the second metallic contact layer, the semiconductor connection layer including two from the group of the first, second and third composition elements.

For example, a concentration of a composition element of the semiconductor contact layer in a region from the second semiconductor layer to the second metallic contact Remove layer. The method may further comprise forming a layer stack, which comprises the first and the second semiconductor layer, before structuring the first semiconductor layer. The first and the second semiconductor layer can in particular be grown epitaxially.

According to further embodiments, an optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and a second contact region for electrically contacting the second semiconductor layer. The second contact region has a second metallic contact layer and a semiconductor contact layer between the second metallic contact layer and the second semiconductor layer. A band gap of a semiconductor material as the semiconductor contact layer decreases from a position on one side of the second semiconductor layer to a position on the side of the second metallic contact layer.

The optoelectronic semiconductor component can furthermore have a semiconductor connection layer between the semiconductor contact layer and the second metallic contact layer. A band gap of a material of the semiconductor connection layer is smaller than the band gap of the second semiconductor layer. For example, the band gap of the semiconductor material of the semiconductor contact layer can be smaller than the band gap of the semiconductor material of the second semiconductor Layer and larger than the band gap of the semiconductor material of the semiconductor connection layer.

According to embodiments, an optoelectronic device contains the above-described optoelectronic semiconductor component. The optoelectronic device can be, for example, a UV lighting device or a UV analysis device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings serve to understand exemplary embodiments of the invention. The drawings illustrate exemplary embodiments and, together with the description, serve to explain them. Further exemplary embodiments and numerous of the intended advantages result directly from the following detailed description. The elements and structures shown in the drawings are not necessarily drawn to scale with respect to one another. The same reference numerals refer to the same or corresponding elements and structures.

FIG. 1A shows a schematic cross-sectional view of an optoelectronic semiconductor component in accordance with embodiments.

The FIG. 1B and IC show schematic top views of the optoelectronic semiconductor component in accordance with embodiments.

The FIG. 2A to 2E show cross-sectional views of a workpiece when performing a method according to embodiments FIG. 3 summarizes a method according to embodiments.

FIG. 4 illustrates an optoelectronic device according to embodiments.

LONG DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part of the disclosure and in which specific exemplary embodiments are shown for purposes of illustration. In this context, a directional terminology such as "top", "bottom", "front", "back", "over", "on", "in front", "behind", "front", "back" etc. is opened the orientation of the fi gures just described related. Since the components of the exemplary embodiments can be positioned in different orientations, the directional terminology is only used for explanation and is in no way restrictive.

The wording “the first semiconductor layer is arranged above the second semiconductor layer” is intended to mean in particular that the first and second semiconductor layers are part of a semiconductor layer stack. Depending on the positioning of the optoelectronic semiconductor component, this wording can also mean that the second semiconductor layer is above the first semiconductor layer is arranged.

The description of the exemplary embodiments is not restrictive, since other exemplary embodiments also exist and structural or logical changes can be made without deviating from the range defined by the claims. In particular, elements of exemplary embodiments described below can have elements can be combined from other of the described exemplary embodiments, unless the context provides otherwise.

The semiconductor materials mentioned in the context of the present description can be based on a direct semiconductor material. Examples of semiconductor materials which are particularly suitable for generating electromagnetic radiation include, in particular, nitride semiconductor compounds through which, for example, ultraviolet, blue or longer-wave light can be generated, such as, for example, GaN, InGaN, A1N, Al-GaN, AlGalnN, AlGalnBN, phosphide semiconductor compounds which, for example, can produce green or long-wave light, such as GaAsP, AlGalnP, GaP, AlGaP, and other semiconductor materials such as AlGaAs, SiC, ZnSe, GaAs, ZnO, Ga2Ct, diamond, hexagonal BN and combinations of the materials mentioned. The stoichiometric ratio of the ternary compounds can vary. Other examples of semiconductor materials can include silicon, silicon germanium and germanium.

The term “substrate” generally encompasses insulating, conductive or semiconductor substrates.

The terms "lateral" and "horizontal", as used in this description, are intended to describe an orientation or alignment that is essentially parallel to a first surface of a substrate or semiconductor body. This can be the surface of a wafer or a chip (die), for example.

The horizontal direction can lie, for example, in a plane perpendicular to a growth direction when layers are grown. The term "vertical", as used in this description, is intended to describe an orientation which is essentially perpendicular to the first surface of a substrate or semiconductor body. The vertical direction can, for example, correspond to a growth direction when layers are grown.

As far as the terms "have", "contain", "comprise", "have" and the like are used here, they are open terms that indicate the presence of said elements or features, the presence of further elements or features but do not rule it out. The undefined articles and the certain articles include both the plural and the singular, unless the context clearly indicates otherwise.

In the context of this description, the term “electrically connected” means a low-resistance electrical connection between the connected elements. The electrically connected elements do not necessarily have to be connected directly to one another. Further elements can be arranged between electrically connected elements.

The term “electrically connected” also includes tunnel contacts between the connected elements.

FIG. 1A shows a vertical cross-sectional view of an optoelectronic semiconductor component 10 according to embodiments.

The optoelectronic semiconductor component 10 comprises a first semiconductor layer 120 of a first conductivity type, for example p-type, and a second semiconductor layer 130 of a second conductivity type, for example n Type. A semiconductor material of the first and second semiconductor layers is in each case a compound semiconductor material which contains a first, a second and a third composition element. The optoelectronic semiconductor component 10 further comprises a second contact region for electrical contacting of the second semiconductor layer 130. The second contact region 135 has a second metallic contact layer 134 and a semiconductor contact layer 132 between the metallic contact layer 134 and the second semiconductor layer 130. A semiconductor material of the semiconductor contact layer 132 contains the first, second and third composition element. The concentration of the first and second composition elements changes from a position on one side of the second semiconductor layer 130 to a position on the side of the metallic contact layer 134.

For example, a semiconductor layer stack, which contains the first and second semiconductor layers 120, 130, is arranged on a transparent substrate 100, for example a sapphire substrate or a native AlN substrate. The substrate can also be constructed from other materials, for example non-transparent materials such as GaN, silicon or silicon carbide. The second semiconductor layer 130 can be arranged between a second main surface 110 of the substrate 100 and the first semiconductor layer 120. According to further embodiments, however, the optoelectronic semiconductor component can also be embodied without a substrate 100.

According to refinements, a buffer layer 138 can furthermore be arranged between substrate 100 and second semiconductor layer 130. The buffer layer 138 can contain an AlN layer and optionally further layers, for example further Al-GaN layers. The buffer layer 138 can cause dislocations and defects in the second semiconductor layer be wrested. For example, the buffer layer may compensate for a lattice mismatch between the substrate 100 and the second semiconductor layer 130. Overall, the crystal quality of the second semiconductor layer 130 can be improved by the presence of the buffer layer 138. For example, the use of a buffer layer 138 may be beneficial in cases where a non-native substrate 100 such as a sapphire substrate is used.

For example, electromagnetic radiation 20 emitted by the optoelectronic semiconductor component can be emitted via a first main surface 105 of the substrate. According to further embodiments, electromagnetic radiation 20 emitted by the optoelectronic semiconductor component can also be emitted via the side of the component which is remote from the substrate 100.

The first main surface 105 is opposite to the second main surface 110. An active region 125 can be arranged between the first and second semiconductor layers 120, 130. The active region 125 can have, for example, a pn junction, a double heterostructure, a single quantum well structure (SQW, single quantum well) or a multiple quantum well structure (MQW, multi quantum well) for generating radiation. The term "quantum well structure" has no meaning with regard to the dimensionality of the quantization. It thus includes, among other things, quantum wells, quantum wires and quantum dots as well as any combination of these layers.

The optoelectronic semiconductor component can furthermore have a semiconductor connection layer 133 between the semiconductor contact layer 132 and the metallic contact layer 134. The semiconductor connection layer 133 may be two the group of the first, second and third composition elements included. For example, if the second semiconductor layer 130 has the composition A _x Bi_ _x C, the semiconductor connection layer 133 can have the composition AC. If the second semiconductor layer 130 has the composition A _x B _y Di_ _xy C, the semiconductor connection layer 133 can have the composition A _x Bi_ _x C. For example, C can represent nitrogen (N). Furthermore, the stoichiometric proportion y of B within the layer can decrease in the semiconductor contact layer 132. For example, the stoichiometric portion y of B on the side facing away from the second semiconductor layer 130 can decrease to almost zero. For example, the proportion of the composition element within the semiconductor contact layer can drop strictly monotonously. Furthermore, it can gradually decrease or gradually. As a result, the band gap within the semiconductor contact layer 132 decreases toward the second metallic contact layer 134. For example, the bandgap of the material of the semiconductor contact layer can decrease from a value that is approximately similar to the bandgap of the material of the second semiconductor layer 130 to a value that corresponds to the bandgap of the semiconductor connection layer 133.

According to embodiments, the semiconductor connection layer 133 can only contain two from the group of the first, second and third composition elements, ie the proportion of the composition element B can be zero. For example, the first semiconductor layer 120 can contain the same composition elements as the second semiconductor layer 130. The composition ratio of the composition elements in the first and second semiconductor layers can each be the same or different from one another. As a result, the semiconductor connection layer 133 has a smaller band gap as the second semiconductor layer 130 and as the semiconductor contact layer 132.

According to embodiments, the second semiconductor layer 133 may contain Al, Ga and N, for example. In this case, for example, the semiconductor connection layer 133 can contain GaN. Furthermore, the Al content decreases in the semiconductor contact layer 132. For example, it can go down within the semiconductor contact layer 132 from a value that is similar to or equal to the value in the second semiconductor layer 130 to a lower value. According to further embodiments, the second semiconductor layer 130 and, if appropriate, the first semiconductor layer 120 can contain (Al, In) GaN. More specifically, the material of the second semiconductor layer 130 can be a quaternary semiconductor material, the proportion of two components in this case being the semiconductor contact layer 132 decreases, so that the band gap within the semiconductor contact layer 132 is reduced. According to further embodiments, the material of the second semiconductor layer 130 can be or contain AlGalnBN, the proportion of second components in the semiconductor contact layer 132 decreasing, so that the band gap within the semiconductor contact layer 132 is reduced.

According to further embodiments, the second semiconductor layer can also contain InGaN. In this case, the Ga content in the semiconductor contact layer 132 can decrease, for example, so that the band gap in the semiconductor contact layer 132 is reduced. Furthermore, the semiconductor connection layer 133 can contain InN. According to further embodiments, the material of the second semiconductor layer can also contain A1BN or GaBN or (Al, Ga) BN. According to embodiments, the semiconductor contact layer 132 and the semiconductor connection layer 133 can each be n-doped. For example, the semiconductor contact layer 132 and the semiconductor connection layer 133 can each be doped with silicon. For example, the silicon content in the semiconductor contact layer 132 can be adapted in accordance with the varying content of the first and second composition elements. For example, the Si doping level can be reduced if the Al content is increased and vice versa. However, the change in the Si doping level depending on the growth parameters can be very small.

For example, a layer thickness of the semiconductor contact layer 132 can be greater than 10 nm, for example 20 to 50 nm, for example 20 to 30 nm. If the layer thickness is too small, the contact resistance is increased. If the layer thickness becomes too large, the forward voltage cannot be reduced any further. A layer thickness of the semiconductor connection layer 133 can be less than 100 nm, for example.

A first metallic contact layer 122 can be arranged above the first semiconductor layer 120 and can be electrically connected to the latter. The first and the second metallic contact layers can contain, for example, a layer stack of different layers, for example Ti / Al / Ti / Au. However, they can also be made up of individual layers. Furthermore, the first and second metallic contact layers can contain a transparent conductive material. This is favorable in cases in which light emission is to take place over the surface of the optoelectronic component on which the first and second metallic contact layers are arranged. The second contact region has a second metallic contact layer and a semiconductor contact layer between the metallic contact layer and the second semiconductor layer. Due to the special nature of the semiconductor contact layer, a band gap of the material of the semiconductor contact layer decreases from a position on the second semiconductor layer to the second metallic contact layer. As a result, the effective Schottky barrier of the second contact area can be greatly reduced. In the presence of the semiconductor connection layer, which has, for example, a smaller band gap than the second semiconductor layer, between the semiconductor contact layer and the metallic contact layer, this effective Schottky barrier of the second contact region can be further reduced. As a result, the corresponding contact resistance is reduced. Due to the reduced contact resistance, the forward voltage of the LED can be reduced. As a result, the efficiency of the LED is increased. Furthermore, because of the reduced forward voltage, it is possible to achieve operation at high currents and an improved service life.

FIG. 1B shows a top view of an optoelectronic semiconductor component in accordance with embodiments. As shown, the second contact areas 135 can be formed in an island-like manner, for example circularly between structured areas of the first semiconductor layer 120. The first metallic contact layer 122 can be formed between the second contact regions 135. The first metallic contact layer 122 does not necessarily have to cover the entire surface of the first semiconductor layer 120. It can also cover the surface of the first semiconductor layer 120 only partially or in sections. According to further embodiments, it is also possible to form the second contact regions 135 in the form of strips, as shown in FIG. IC is shown. In this case, strips of the second contact region 135 can alternate with strips of the first metallic contact layer 122 and, for example, form a finger structure. It goes without saying that these layouts are only given as an example and any layouts of the first metallic contact layer 122 and the second contact regions 135 can be used.

With the described LED, for example, electromagnetic radiation in the deep UV range can be generated, i.e. at wavelengths from 206 to 360 nm. For example, the emitted wavelength range can be in a range from 217 to 280 nm. The described structure of the second contact region can be used, for example, in cases in which a semiconductor material with a large band gap is used and in which the activation energy of the dopant of the second semiconductor layer is high. In this case, the bandgap can be narrowed by the semiconductor contact layer as the concentration of a composition element decreases. As a result, the Schottky barrier can be reduced.

According to embodiments, the first semiconductor layer 120 may be p-doped and the second semiconductor layer 130 may be n-doped. The second semiconductor layer 130 can, for example, contain a nitride semiconductor material such as GaN or A1N and be doped with silicon. In this case the activation energy of the dopant is high. According to further embodiments, the first semiconductor layer 120 can be n-doped and the second semiconductor layer 130 can be p-doped. In this case, for example, the second semiconductor layer 130 can contain a nitride semiconductor material such as GaN or A1N and be doped with magnesium. In the following, with reference to FIG. 2A to 2E a method for producing the optoelectronic semiconductor component according to embodiments described.

Above the second main surface 110 of an insulating substrate 100, for example a sapphire substrate, a buffer layer 138 can first be grown as described above. Then a second semiconductor layer 130 of a second conductivity type, for example an n-type, can first be grown. For example, this can be an AlGaN layer doped with silicon. An active region 125 is formed over it. The first semiconductor layer 120 of the first conductivity type, for example p-type, can then be formed. For example, this layer can also be an AlGaN layer. According to further embodiments, however, this can also be a layer stack made of GaN with any admixtures of Al. For example, different p-doped AlGaN layers with different compositions and doping levels can first be formed. Finally, for example, a p-doped GaN layer can be grown. In addition, an active region 125 may be formed as described above. FIG. 2A shows a cross-sectional view of a resulting workpiece 15.

Then, as shown in FIG. 2B illustrates trenches 141, for example formed by etching, the adjacent mesas

Separate 140 from each other. The trenches 141 can, for example, as shown in FIG. 1B illustrates having a circular or oval shape. According to further embodiments, the trenches can

141, however, also extend in a strip shape in a direction perpendicular to the cross section. Depending on the dimension of the trenches 141, the dimension of the second contact adjust empire. For example, the contact resistance can be further reduced by enlarging the second contact area. For example, a lateral dimension s of the trenches 141 can be 5 μm to 30 μm, for example approximately 10 μm.

Then, as shown in FIG. 2C illustrates a mask layer 144 formed over the resulting structure. For example, the mask layer can contain silicon dioxide. The mask layer 144 can, for example, be deposited conformally. The layer thickness of the mask layer can, for example, be dimensioned such that a desired distance between the second contact area and the first semiconductor layer 120 is set. If the layer thickness of the mask layer 144 becomes too large, the contact resistance can be reduced due to the reduced contact area. Subsequently, the mask layer 144 is opened on the bottom side of the trenches 141, for example by etching, with the formation of openings 145, so that part of a surface 131 of the second semiconductor layer 130 is uncovered and exposed.

Then another step to perform an epitaxy procedure is performed. First, the semiconductor contact layer 132 is formed with a changing composition ratio. This can be done by adjusting the concentration of the supplied gases. For example, the Al content can decrease in the semiconductor contact layer 132. The method for forming the semiconductor connection layer is a selective method, ie it is only grown on the exposed areas 131 of the second semiconductor layer 130. A semiconductor connection layer 133 can then be formed over the semiconductor contact layer. FIG. 2D shows an example of a resulting workpiece 15. After removing the mask layer, as shown in FIG. 2E illustrates a metal layer. Forming the metal layer may include, for example, forming multiple layers of suitable materials, such as Ti, Al, Ni Au, and mixtures of these materials. This metal layer forms the second metallic contact layer 134 over the semiconductor contact layer and the semiconductor connection layer, which results in a second contact region 135. Furthermore, the metal layer over the first semiconductor layer forms the first metallic contact layer 122.

As a result, this results in FIG. 1A shown semiconductor device.

The method can be modified in a suitable manner if, for example, the first semiconductor layer is of the n-type and the second semiconductor layer is of the p-type. Furthermore, according to embodiments, the substrate 100 can be removed after performing the described method steps.

FIG. 3 summarizes a method according to embodiments.

A method for producing an optoelectronic semiconductor component comprises forming (S100) a layer stack which comprises a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type, wherein a semiconductor material of the first and second semiconductor layer is in each case a compound semiconductor material which is contains a first, a second and a third composition element, and forming (S110) a semiconductor contact layer and a second metallic contact layer, a second contact region being formed for electrically contacting the second semiconductor layer. The semiconductor contact layer is formed between the second metallic contact layer and two ter semiconductor layer. A semiconductor material of the semiconductor contact layer contains the first, second and third composition element, wherein a concentration of the first and second composition element changes from a position on one side of the second semiconductor layer to a position on the side of the second metallic contact layer. The method may further include forming (S120) a semiconductor connection layer between the semiconductor contact layer and the second metallic contact layer, the semiconductor connection layer including two from the group of the first, second and third composition elements.

FIG. 4 shows an optoelectronic device which contains the optoelectronic semiconductor component described above. For example, the optoelectronic device can be a UV lighting device, which can be used, for example, for disinfection or for skin treatment or for curing polymers. For example, it can also be an analysis device for the detection of gases such as ammonia or sulfur oxides.

Although specific embodiments have been illustrated and described herein, those skilled in the art will recognize that the specific embodiments shown and described may be replaced by a variety of alternative and / or equivalent configurations without departing from the scope of the invention. The application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, the invention is limited only by the claims and their equivalents. LIST OF REFERENCE NUMBERS

10 Optoelectronic semiconductor component

15 workpiece

20 emitted electromagnetic radiation

30 Optoelectronic device

100 transparent substrate

105 first main surface

110 second main surface

120 first semiconductor layer

122 first metallic contact layer

125 active area

130 second semiconductor layer

131 exposed part of the second semiconductor layer 132 semiconductor contact layer

133 semiconductor compound layer

134 second metallic contact layer

135 second contact area

133 buffer layer

140 mesa

141 trench

144 mask layer

145 opening

Claims

1. Optoelectronic semiconductor component (10), comprising:

a first semiconductor layer (120) of a first conductivity type;

a second semiconductor layer (130) of a second conductivity type, a semiconductor material of the first and second semiconductor layer (120, 130) each being a compound semiconductor material which contains a first, a second and a third composition element, and

a second contact area (135) for electrically contacting the second semiconductor layer (130),

wherein the first semiconductor layer (120) is arranged and structured above the second semiconductor layer (130) and the second contact region (135) is arranged between structured regions of the first semiconductor layer,

the second contact region (135) has a second metallic contact layer (134) and a semiconductor contact layer (132) between the metallic contact layer (134) and the second semiconductor layer (130), and

a semiconductor material of the semiconductor contact layer (132) contains the first, second and third composition elements, the concentration of the first and second composition elements varying from a position on one side of the second semiconductor layer (130) to a position on the side of the second metallic contact layer (134 ) changes.

2. Optoelectronic semiconductor component (10) according to claim 1, further comprising a semiconductor connection layer (133) between the semiconductor contact layer (132) and the second metallic contact layer (134), the semiconductor Connection layer (133) contains two from the group of the first, two th and third composition elements.

3. Optoelectronic semiconductor component (10) according to claim 2, in which a band gap of a material of the semiconductor compound layer is smaller than the band gap of the second semiconductor layer.

4. Optoelectronic semiconductor component (10) according to claim 2 or 3, wherein the semiconductor connection layer (133) contains only two from the group of the first, second and third composition elements.

5. Optoelectronic semiconductor component (10) according to one of the preceding claims, in which a concentration of a composition element of the semiconductor contact layer (132) decreases in a region from the second semiconductor layer (130) to the second metallic contact layer (134).

6. Optoelectronic semiconductor component (10) according to one of the preceding claims, wherein the first semiconductor layer (120) contains a plurality of sub-layers of the same composition elements, wherein the doping level or composition ratio of the composition elements differs in at least two un-layers.

7. The optoelectronic semiconductor component (10) according to one of the preceding claims, in which the composition elements of the second semiconductor layer (130) are each selected from the group consisting of In, Al, Ga, B and N.

8. A method for producing an optoelectronic semiconductor component, comprising: Structuring a first semiconductor layer of a first conductivity type, which is arranged over a second semiconductor layer of a second conductivity type, so that the first semiconductor layer is removed from parts of the second semiconductor layer and structured regions of the first semiconductor layer are formed, a semiconductor material being the each of the first and second semiconductor layers is a compound semiconductor material which contains a first, a second and a third composition element, and

Forming a semiconductor contact layer and a second metallic contact layer between the structured regions of the first semiconductor layer (120), a second contact region being formed for electrical contacting of the second semiconductor layer,

wherein the semiconductor contact layer is formed between the second metallic contact layer and the second semiconductor layer, and

a semiconductor material of the semiconductor contact layer contains the first, second and third composition elements, where a concentration of the first and second composition elements changes from a position on one side of the second semiconductor layer to a position on the side of the second metallic contact layer.

9. The method of claim 8, wherein the semiconductor contact layer is formed by selective epitaxial growth over exposed areas of the second semiconductor layer.

10. The method of claim 8 or 9, further comprising:

forming (S120) a semiconductor connection layer between the semiconductor contact layer and the second metallic contact layer, the semiconductor Connection layer contains two from the group of the first, second and third composition elements.

11. The method according to any one of claims 8 to 10, wherein a concentration of a composition element of the semiconductor contact layer decreases in a region from the second semiconductor layer to the second metallic contact layer.

12. The method according to any one of claims 8 to 11, further comprising forming a layer stack, which comprises the first and the second semiconductor layer, before structuring the first semiconductor layer.

13. Optoelectronic semiconductor component (10), comprising:

a first semiconductor layer (120) of a first conductivity type;

a second semiconductor layer (130) of a second conductivity type, and

the second contact region (135) has a second metallic contact layer (134) and a semiconductor contact layer (132) between the second metallic contact layer (134) and the second semiconductor layer (130), and

a band gap of a semiconductor material of the semiconductor contact layer (132) decreases from a position on one side of the second semiconductor layer (130) to a position on the side of the second metallic contact layer (134).

14. Optoelectronic semiconductor component (10) according to claim 13, further comprising a semiconductor connection layer (133) between the semiconductor contact layer (132) and the second metallic contact layer (134), the band gap of a material of the semiconductor connection layer (133) being smaller than the band gap of the second semiconductor layer.

15. Optoelectronic semiconductor component (10) according to claim 14, in which the band gap of the semiconductor material of the semiconductor contact layer is smaller than the band gap of the semiconductor material of the second semiconductor layer (133) and larger than the band gap of the semiconductor material of the semiconductor connection layer (133).

16. Optoelectronic device (30) with the optoelectronic African semiconductor component (10) according to one of claims 1 to 7 and 13 to 15.

17. The optoelectronic device (30) according to claim 16, which is a UV illumination device or a UV

Analyzer is.