Light-emitting semiconductor device, optoelectronic component, projection device, and electronic device

Abstract

It is a light-emitting semiconductor device, an optoelectronic component, a projection device, and an electronic device. The light-emitting semiconductor device (10) includes a semiconductor laminate (105) including a first semiconductor layer (110) of a first conductivity type, an active zone (115) that generates electromagnetic radiation, and a second semiconductor layer (120) of a second conductivity type. The light-emitting semiconductor device (10) further includes a current diffusion layer (125) on the surface of the semiconductor laminate (105) electrically connected to the first semiconductor layer (110), and a dielectric layer (128) on the current diffusion layer (125). A metal layer (129) is disposed so as to face at least a part of the current diffusion layer (125), and the dielectric layer (128) is disposed between the current diffusion layer (125) and the metal layer (129). The light-emitting semiconductor device (10) further includes a readout circuit (130) configured to be electrically connectable to the metal layer (129) and read out the capacitance between the metal layer (129) and the current diffusion layer (125).

Description

Technical Field

[0001] The present application relates to a light-emitting semiconductor device, an optoelectronic component, a projection device, and an electronic device.

Background Art

[0002] Semiconductor laser devices are increasingly being used in various applications such as projectors, laser scanners, and LIDAR (Light Detection and Ranging) systems. During operation, the temperature of the laser can rise, which may change the wavelength, brightness, and stability of the laser characteristics. Furthermore, the lifespan of the laser device can be extended by careful temperature monitoring. Therefore, methods for measuring the temperature of laser devices and further semiconductor devices are being studied.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide an improved light-emitting semiconductor device, an improved optoelectronic component, and an improved projector. Furthermore, an object is to provide an improved method for measuring the temperature of a light-emitting semiconductor device.

Means for Solving the Problems

[0004] According to an embodiment, the above object is achieved by the matters described in the independent claims. Further developments are defined in the dependent claims.

[0005] The light-emitting semiconductor device includes a semiconductor laminate including a first semiconductor layer of a first conductivity type, an active zone for generating electromagnetic radiation, and a second semiconductor layer of a second conductivity type. The light-emitting semiconductor device further includes a current diffusion layer on the surface of the semiconductor laminate, which is electrically connected to the first semiconductor layer, and a dielectric layer on the current diffusion layer. A metal layer is arranged so as to face at least a part of the current diffusion layer, and the dielectric layer is arranged between the current diffusion layer and the metal layer. The light-emitting semiconductor device further includes a readout circuit that can be electrically connected to the metal layer and is configured to read out the capacitance between the metal layer and the current diffusion layer.

[0006] With such a configuration, the temperature of the semiconductor laminate can be determined.

[0007] For example, the metal layer may include at least two regions arranged along the horizontal direction and insulated from each other. Therefore, the spatial distribution of the temperature in the semiconductor laminate may be determined.

[0008] For example, the light-emitting semiconductor device can be realized as a laser, such as an edge-emitting laser or a surface-emitting laser having a horizontal resonator.

[0009] According to a further embodiment, the light-emitting semiconductor device can be a VCSEL (vertical cavity surface emitting laser) or an LED (light-emitting diode).

[0010] For example, the semiconductor laminate may be patterned to form a ridge, and the current diffusion layer may be arranged on the first main surface of the ridge.

[0011] The readout circuit may be configured to determine the temperature of the semiconductor laminate.

[0012] For example, when the metal layer includes at least two regions arranged along the horizontal direction and insulated from each other, the reading circuit may be configured to determine the spatial distribution of temperature. For example, the determination of the spatial distribution may be performed based on a first capacitance between a first portion of the metal layer and the current diffusion layer, and further based on a second capacitance between a second portion of the metal layer and the current diffusion layer.

[0013] The light-emitting semiconductor device may further include a driver configured to supply current to the current diffusion layer. The driver may be connectable to the reading circuit and may be configured to change the current according to the capacitance read by the reading circuit. Thereby, the injection current may be controlled based on the detected temperature.

[0014] According to a further embodiment, the optoelectronic component includes a first semiconductor layer of a first conductivity type, an active zone for generating electromagnetic radiation, and a second semiconductor layer of a second conductivity type, and includes a semiconductor laminate patterned into a plurality of ridges. The optoelectronic component further includes a plurality of current diffusion layers disposed on a first main surface of the ridge and electrically connected to the first semiconductor layer in each ridge, and a dielectric layer on the current diffusion layer. Sections of the metal layer are arranged to face corresponding ones of the current diffusion layers, and the dielectric layer is disposed between the current diffusion layer and the sections of the metal layer. The optoelectronic component further includes a reading circuit electrically connectable to the sections of the metal layer and configured to read the capacitance between the sections of the metal layer and the corresponding current diffusion layer.

[0015] For example, the reading circuit is further configured to determine the temperature of the corresponding ridge.

[0016] The optoelectronic component may further include a driver for determining the current supplied to a corresponding one of the current diffusion layers. The driver may be connectable to the reading circuit and may be configured to determine the current supplied based on the temperature detected by the reading circuit.

[0017] A further embodiment relates to a method for determining the temperature of a light-emitting semiconductor device including a semiconductor laminate including a first semiconductor layer of a first conductivity type, an active zone for generating electromagnetic radiation, and a second semiconductor layer of a second conductivity type, a current diffusion layer on the surface of the semiconductor laminate electrically connected to the first semiconductor layer, a metal layer disposed to face at least a part of the current diffusion layer, and a dielectric layer between the current diffusion layer and the metal layer. The method includes determining the capacitance of a capacitor including the metal layer, the dielectric layer, and the current diffusion layer, and determining the temperature of the semiconductor laminate based on the determined capacitance.

[0018] For example, the metal layer may include a first region and a second region arranged along the horizontal direction and insulated from each other. The method may further include determining the spatial distribution of the temperature of the semiconductor laminate based on the determined capacitances of a first capacitor including the first region of the metal layer and a second capacitor including the second region of the metal layer.

[0019] A light-emitting semiconductor device according to a further embodiment includes a semiconductor laminate including a first semiconductor layer of a first conductivity type, an active zone for generating electromagnetic radiation, and a second semiconductor layer of a second conductivity type. The light-emitting semiconductor device further includes a current diffusion layer on the surface of the semiconductor laminate electrically connected to the first semiconductor layer, a metal layer disposed to face at least a part of the current diffusion layer, and a dielectric layer between the current diffusion layer and the metal layer. The material of the dielectric layer is selected from BaTiO3, PbMgNbO3, PbTiO3, PbLaZrTiO3, BaSrTiO3, TiO2, Ta2O5, CeO2, BaZrTiO3, SiO2, Si3N4, SrTiO3, PrScO3, SmScO3, SrTiO3, TbScO3, DyScO3, and LiNbO3.

[0020] For example, the light-emitting semiconductor device of the present invention includes a capacitor that functions as an integrated temperature sensor.

[0021] The projection device includes the above-described light-emitting semiconductor device or the above-described optoelectronic component.

[0022] The electronic device includes the above-described light-emitting semiconductor device, the above-described projection device, or the above-described optoelectronic component.

[0023] For example, the electronic device can be selected from a computer, a laptop, a smartphone, a laser scanner, and a LIDAR system.

[0024] The accompanying drawings are included to provide a further understanding of the embodiments of the present invention, are incorporated herein, and constitute a part hereof. The drawings illustrate embodiments of the present invention and are helpful in explaining the principles together with the description thereof. Many other embodiments of the present invention and intended advantages will be readily understood as the following detailed description is read and understood. The elements of the drawings are not necessarily to scale with each other. Like reference numerals indicate corresponding like parts.

Brief Description of the Drawings

[0025]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 5A

Figure 5B

Figure 5C

Figure 6A

Figure 6B

Figure 6C

Figure 7

Figure 8A

Figure 8B

Embodiments for Carrying Out the Invention

[0026] In the following detailed description, reference is made to the accompanying drawings which form a part hereof and which show by way of illustration specific embodiments in which the invention may be practiced. In this regard, the terms such as "top", "bottom", "front", "back", "over", "on", "above", "leading", "trailing", etc. with respect to directions are used with reference to the orientation of the following described drawings. Since the components of the embodiments of the present invention can be arranged in many different orientations, the terms with respect to directions are used for purposes of explanation and are in no way limiting. It should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims.

[0027] The description of the embodiments is not restrictive. In particular, the elements of the embodiments described below can be combined with the elements of different embodiments.

[0028] As used in the following description, the terms "wafer" or "semiconductor substrate" may include any semiconductor-based structure having a semiconductor surface. The wafer and structure are to be understood to include doped and undoped semiconductors, such as epitaxial semiconductor layers supported by a base semiconductor foundation, and other semiconductor structures. For example, a layer of a first semiconductor material may be grown on a growth substrate of a second semiconductor material. According to further embodiments, the growth substrate may be an insulating substrate such as a sapphire substrate. Depending on the intended use, the semiconductor may be based on a direct or indirect semiconductor material. Examples of semiconductor materials particularly suitable for the generation of electromagnetic radiation include nitride compound semiconductors such as GaN, InGaN, AlN, AlGaN, AlGaInN, which can generate ultraviolet light, blue light or light of longer wavelengths, and phosphide compound semiconductors such as GaAsP, AlGaInP, GaP, AlGaP, which can generate green light or light of longer wavelengths, and further semiconductor materials such as AlGaAs, SiC, ZnSe, GaAs, ZnO, Ga2O3, diamond, hexagonal BN, and combinations of these materials. Further examples of semiconductor materials may be silicon, silicon germanium, and germanium. The stoichiometric ratio of compound semiconductor materials may vary. In the context of this specification, the term "semiconductor" further encompasses organic semiconductor materials.

[0029] As used herein, the term "vertical" is intended to refer to an orientation that is perpendicular to a first surface of a substrate or semiconductor body.

[0030] As used herein, the terms "lateral (or transverse)" and "horizontal" are intended to refer to an orientation that is parallel to a first surface of a substrate or semiconductor body. This may be, for example, the surface of a wafer or die.

[0031] As used herein, terms such as "have", "contain", "possess", "include" are open-ended terms indicating the presence of the recited elements or features and do not exclude additional elements or features. The articles "a", "an", and "the" (even in this translation where there is no term referring to the plural such as "theirs", etc.) are intended to include not only the singular form but also the plural form unless specifically indicated otherwise.

[0032] FIG. 1A shows a cross-sectional view of a light-emitting semiconductor device 10 according to an embodiment. The light-emitting semiconductor device includes a semiconductor laminate 105 including a first semiconductor layer 110 of a first conductivity type, for example, a p-type, an active zone 115 for generating electromagnetic radiation, and a second semiconductor layer 120 of a second conductivity type, for example, an n-type.

[0033] The active zone 115 may be disposed between the first semiconductor layer and the second semiconductor layer. The active zone may include, for example, a pn junction for generating radiation, a double heterostructure, a single quantum well (SQW) structure, or a multiple quantum well (MQW) structure. In this process, the term "quantum well structure" does not have a meaning related to the dimensionality of quantization. Thus, the term "quantum well structure" includes quantum wells, quantum wires, quantum dots, and any combination of these layers.

[0034] For example, the semiconductor laminate may further include a semiconductor substrate 100. For example, the semiconductor substrate 100 may be a growth substrate for growing the semiconductor laminate 105. Also, the semiconductor laminate 105 may include additional layers.

[0035] The light-emitting semiconductor device is disposed on the surface of the semiconductor stack 105 and further includes a current diffusion layer 125 that is electrically connected to the first semiconductor layer 110. The current diffusion layer 125 may include a sub-layer (not shown in FIG. 1A). The current diffusion layer 125 may be disposed in direct contact with the first semiconductor layer 110. For example, the current diffusion layer 125 may distribute and inject a current for generating the electromagnetic radiation 15. According to an embodiment, the light-emitting semiconductor device 10 may realize an edge-emitting laser. The light-emitting semiconductor device may include a first resonator mirror 111 and a second resonator mirror 112. A cavity or a laser resonator may be formed between the first resonator mirror 111 and the second resonator mirror 112. The first resonator mirror and the second resonator mirror may be disposed on the sidewalls of the semiconductor stack 105. For example, the reflectivity of the first resonator mirror 111 may be smaller than the reflectivity of the second resonator mirror 112. The first resonator mirror 111 may realize an extraction mirror for extracting the generated electromagnetic radiation 15.

[0036] The dielectric layer 128 is disposed on the current diffusion layer 125. Also, the metal layer 129 is disposed so as to face at least a part of the current diffusion layer 125. The dielectric layer 128 is disposed between the current diffusion layer 125 and the metal layer 129.

[0037] For example, the material of the dielectric layer 128 can be selected from the group including silicon oxide (SiO2), silicon nitride (Si3N4), aluminum oxide (Al2O3), aluminum nitride (AlN), or barium titanate (BaTiO3). For example, a material having a relatively large dielectric constant, such as barium titanate, may be selected. Further, the dielectric constant may depend on temperature. For example, when the temperature difference is 30K, the difference in dielectric constant may be greater than 0.2. According to a further embodiment, when the temperature difference is 30K, the corresponding difference in dielectric constant may be greater than 10, or greater than 100. Materials particularly suitable for the dielectric layer include the following materials: PbMgNbO3, PbTiO3, PbLaZrTiO3, BaSrTiO3, TiO2, Ta2O5, CeO2, BaZrTiO3, SrTiO3, PrScO3, SmScO3, SrTiO3, TbScO3, DyScO3, LiNbO3.

[0038] The capacitor 118 is formed between the metal layer 129 and the current diffusion layer 125. By monitoring the capacitance of the capacitor 118, a change in temperature may be detected. For example, the light-emitting semiconductor device may further include a readout circuit 130 that can be electrically connected to the metal layer and is configured to read out the capacitance between the metal layer 129 and the current diffusion layer 125. For example, the readout circuit 130 may be electrically connected to the metal layer as shown in FIG. 1A.

[0039] For example, the light-emitting semiconductor device may further include a contact pad 131 that can be connected to the current diffusion layer 125 by a via contact 132 extending through the dielectric layer 128. The contact pad 131 may be connected to an appropriate terminal 133 for injecting current into the light-emitting semiconductor device 10. The substrate 100 or a further component electrically connected to the second semiconductor layer 120 may be electrically connected to the second terminal 134.

[0040] Various modifications of the light-emitting semiconductor device 10 are possible. For example, according to a further embodiment, the generated electromagnetic radiation 15 may be output onto the main surface of the light-emitting semiconductor device 10 at a position not covered by, for example, the metal layer 129.

[0041] FIG. 1B shows an equivalent circuit diagram of the light-emitting semiconductor device 10 shown in FIG. 1A. The light-emitting semiconductor device 10 includes a light-emitting element 20 which is, for example, a light-emitting diode or a laser diode. The light-emitting element 20 may be electrically connected to a driver 140 that injects current into the light-emitting element 20.

[0042] When an appropriate current (indicated by a dashed line) is injected, the light-emitting element 20 emits electromagnetic radiation 15. The light-emitting element 20 is further connected to a capacitor 118 configured to be connected to a readout circuit 130.

[0043] The light-emitting element 20 may be driven by the driver 140. According to an embodiment, the driver 140 may be connected to the readout circuit 130. For example, the current supplied to the light-emitting semiconductor device 10 may be controlled according to the temperature of the semiconductor laminate 105. As described above, the emission wavelength of the light-emitting semiconductor device 10 may depend on the temperature. Therefore, by controlling the injected current, the emission wavelength can be further controlled. Also, when the temperature of the semiconductor laminate 105 changes, the light-emitting semiconductor device 10 may be turned off or operated at different timings.

[0044] FIG. 2A shows a figure cited from Fayos-Fernandez, Jose et al., "Temperature-dependent complex permittivity of several electromagnetic susceptors at 2.45 GHz", Delft, AMPERE Newsletter Editor (2018), Issue 95, March 12, 2018. The figure shows the relative permittivity (ε rOr shows the dependence of the relative permittivity. As shown in the figure, the relative permittivity increases with temperature. For example, at a temperature of 30 °C, the relative permittivity is between 2.9 and 3.0. At a temperature of 80 °C, the relative permittivity is about 3.2.

[0045] FIG. 2B shows a figure cited from Savran, Mehmet Tugrul, "Investigating the effect of temperature on the dielectric constant of ceramic (BaTiO3)", IB thesis, January 1, 2014. The figure shows the relative permittivity of BaTiO3. As shown in the figure, the relative permittivity decreases with temperature. For example, at a temperature of 25 °C, the relative permittivity is between 1000 and 1200. At a temperature of 95 °C, the relative permittivity is less than 200. As can be seen from FIGS. 2A and 2B, by monitoring the capacitance of the capacitor, the temperature change or the absolute temperature of the light-emitting semiconductor device may be determined. In particular, the temperature can be measured without the need for an additional temperature sensor. Also, the temperature may be measured while operating the light-emitting semiconductor device. Furthermore, a light-emitting semiconductor device provided with a temperature sensor can be realized in a small size.

[0046] FIG. 3A shows a cross-sectional view of a semiconductor laser device. The position of the cross-sectional view of FIG. 1A is indicated by A-A in FIG. 3A. The cross-sectional view of FIG. 3A is taken perpendicular to the exit surface of the generated electromagnetic radiation 15. The semiconductor stack 105 is patterned to form a ridge, and as a result, the side walls of the ridge are adjacent to the dielectric layer 128. As shown in the figure, in particular, the stack including the first semiconductor layer 110, the second semiconductor layer 120, and the active zone 115 is patterned to form a ridge. According to a further embodiment, only the first semiconductor layer 110 may be patterned to form a ridge, and the second semiconductor layer 120 and the active zone 115 may be formed in a portion below the ridge. For example, this portion is not patterned.

[0047] The current diffusion layer 125 may be disposed on the main surface of the ridge. The metal layer 129 may be formed on the current diffusion layer 125 and may have a width larger than that of the current diffusion layer 125. The width may be measured in a direction (e.g., the y direction) perpendicular to the extending direction of the ridge (e.g., the x direction). The metal layer 129 faces the current diffusion layer 125. The metal layer 129 may be connected to or connectable to the readout circuit 130.

[0048] FIG. 3B shows a bonding top view of the light-emitting semiconductor device 10 according to an embodiment. In particular, the bonding top view of FIG. 3B is intended to show un-covered components, and further, in order to explain the layout of the semiconductor device, it is intended to show components covered by further components. As shown in FIG. 3B, the metal layer 129 is disposed on the current diffusion layer 125. The area of the metal layer 129 may be larger than the area of the current diffusion layer 125. Also, the contact pad 131 may be connected to the current diffusion layer 125 by the via contact 132. The area of the metal layer 129 may be larger than the area of the contact pad 131.

[0049] According to a further embodiment, the metal layer may include at least two regions 1291, 1292, 1293 arranged along the horizontal direction and insulated from each other. For example, the regions 129 i of the metal layer may be arranged along the extending direction (e.g., the x direction) of the current diffusion layer 125. The presence of these regions improves the resolution of temperature measurement and enables measurement of the temperature gradient along the extending direction of the current diffusion layer 125. For example, the spatial distribution of temperature may be evaluated. Thus, it may become possible to predict the temperature behavior of the light-emitting semiconductor device. The readout circuit 130 may be connectable to different regions by, for example, a switch. For example, the readout circuit 130 may be sequentially connected to any of the regions 129 i in turn.

[0050] FIG. 4B shows an equivalent circuit diagram of the light-emitting semiconductor device 10 shown in FIG. 4A. As shown, the light-emitting element 20 is connected in parallel with a plurality of capacitors 1181, 1182, 1183. The plurality of capacitors 1181, 1182, 1183 are connected in parallel. Each of the capacitors 118 i may be electrically connected to the readout circuit 130. The light-emitting element 20 may be driven by the driver 140. According to an embodiment, the driver 140 may be connected to the readout circuit 130. For example, the current supplied to the light-emitting semiconductor device 10 may be controlled according to the temperature of the semiconductor laminate 105. As described above, the emission wavelength of the light-emitting semiconductor device 10 may depend on the temperature. Therefore, by controlling the injected current, the emission wavelength can be further controlled. Also, when the temperature of the semiconductor laminate 105 changes, the light-emitting semiconductor device 10 may be turned off or operated at different timings. According to a further embodiment, for example, if the temperature behavior of the semiconductor laminate 105 can be predicted by a specific configuration shown in FIGS. 4A and 4B, there may be a possibility of performing more accurate control of the driver 140.

[0051] FIG. 4C shows a schematic cross-sectional view of the optoelectronic component 30 according to an embodiment. The cross-sectional view of FIG. 4C is a cross-sectional view taken along the y direction perpendicular to the extending direction of the current diffusion layer 125. The optoelectronic component shown in FIG. 4C includes elements similar to the above-described light-emitting semiconductor device. Different from the embodiment shown in FIG. 3A, the optoelectronic component 30 includes a plurality of ridges. More specifically, the semiconductor laminate 105 is patterned to form a plurality of ridges 116. The current diffusion layer 125 may be disposed on the first main surface of each of the ridges 116. Sections of the metal layers 1291, 1292, 1293 may be disposed on each of the ridges. For example, each of the sections of the metal layer 129 may face the corresponding current diffusion layer 125. The dielectric layer 128 is disposed between the current diffusion layer 125 and the corresponding one of the metal layer sections 129 i among them.

[0052] The optoelectronic component 30 shown in Fig. 4C refers to a plurality of ridge systems. For example, the presence of a plurality of ridges can illuminate a wider field of view. According to a further embodiment, for example, by using resonators with different resonator lengths or different resonator mirrors having different dependencies on the emission wavelength, each of the ridges can be configured to emit different wavelengths. The light-emitting semiconductor device may further include a connectable readout circuit 130 that can be electrically connected to each section of the metal layers 1291, 1292, 1293 using, for example, a switch 136.

[0053] Fig. 4D shows an equivalent circuit diagram of the plurality of ridge devices shown in Fig. 4C. For example, the elements of drivers 1401, 1402, 1403 may be assigned to each of the different ridges 116 (represented by different light-emitting elements 201, 202, 203 in Fig. 4D). Thus, each of the elements of drivers 1401, 1402, 1403 can drive a corresponding one of the light-emitting elements 201, 202, 203. The different elements of drivers 1401, 1402, 1403 may be separate or may be combined into one driver 140. As further illustrated, the metal layer can be divided into parts, and a plurality of capacitors 1181,... 118 n are assigned to the light-emitting elements 201, 202, 203 respectively. Each of the light-emitting elements 201, 202, 203 emits electromagnetic radiation 15 of the same or different wavelengths.

[0054] FIG. 5A shows an equivalent circuit diagram schematically showing the capacitance within the light-emitting semiconductor device and, hence, the passive sensing method for determining the temperature. As already described, driver 140 supplies a corresponding current signal to light-emitting element 20. For example, the current signal may be a periodically varying signal. Optionally, a reference signal may be branched off and supplied to readout circuit 130 before the current signal reaches light-emitting element 20. The current signal is applied to light-emitting element 20. Capacitor 118 shares a circuit node with light-emitting element 20 as described above. Readout circuit 130 may include a capacitive sensor configured to determine the capacitance of capacitor 118.

[0055] FIG. 5B shows the light-emitting semiconductor device 10 in more detail, including the components of readout circuit 130. Readout circuit 130 may include a central controller 150 that can control the measurement process. Central controller 150 may be implemented in hardware, software, or a combination thereof. Each component of the light-emitting semiconductor device will be described with reference to the waveforms shown in FIG. 5C.

[0056] For example, central controller 150 may set switch 136 to one of the selected ones of capacitors 1181, 1182, 1183 (e.g., signal C_SW). Central controller 150 can, for example, trigger capacitance-voltage converter 151 (e.g., C_C2V_TRG). For example, the capacitance-voltage converter may convert the measured capacitance to a voltage using, for example, an impedance circuit.

[0057] When the capacitance-voltage conversion is completed, the corresponding signal (e.g., C_C2V_RDY) is sent to the central controller 150. The central controller 150 triggers the sample-and-hold circuit 152 to store the analog output of the capacitance-voltage converter 151 (e.g., signal C_SH_TRG). After storing the analog voltage, the central controller 150 triggers the analog-to-digital converter 153 (e.g., signal C_ADC_TRG) and sets the switch 136 and the capacitance-voltage converter 151 to the next capacitor. When the conversion by ADC153 is completed, it sends a signal to the central controller 150 (C_ADC_RDY). At this point, the ADC reading represents the capacitance related to the voltage. To extract the temperature information, this voltage is converted to temperature. For example, this can be achieved by the voltage-temperature block 154 (C_V2T_TRG). For example, the temperature-voltage block 154 may include a look-up table for the conversion. The voltage-temperature block 154 may be realized by sequential logic or combinational logic.

[0058] When the conversion is completed, the voltage-temperature converter 154 places the valid data on the data bus and sends a signal to the central controller 150 (C_V2T_RDY). The central controller 150 sends an address to the memory 155 (MEM_ADDR) and triggers a memory write signal (MEM_WR). For example, the data is sequentially stored in the memory 155 row by row. After storing the temperature information of the capacitor C1, the controller 150 continues with the remaining capacitors. After a while, the temperature map of the laser is stored in the memory 155. This information can be used for further analysis or correction. For example, as described above, the driver 120 may receive data from the memory 155 and control the current supply to the light-emitting semiconductor device 10 or the optoelectronic component 30.

[0059] FIG. 6A shows a cross-sectional view of a light-emitting semiconductor device 10 according to a further embodiment. The light-emitting semiconductor device 10 may include a semiconductor laminate 105 including a first semiconductor layer 110, a second semiconductor layer 120, and an active zone 115 disposed between the first semiconductor layer 110 and the second semiconductor layer 120. A second contact layer 138 may be disposed on the surface of the second semiconductor layer 120. For example, the second contact layer 138 may be made of a transparent material such as ITO (indium tin oxide), or may be patterned into a finger-like pattern. The second contact layer 135 may be electrically connected to a second contact pad 135. The second contact pad 135 may be disposed on the carrier 103. The current diffusion layer 125 may be disposed in contact with the first semiconductor layer 110. The dielectric layer 128 and the metal layer 129 may be disposed on the side of the current diffusion layer 125 opposite to the semiconductor laminate 105. The current diffusion layer 125, the dielectric layer 128, and the metal layer 129 form a capacitor 118. The metal layer 129 may be disposed on the substrate 100. The layer laminate including the semiconductor laminate 105 and the capacitor 118 may be disposed on the carrier 103. The current diffusion layer 125 may be electrically connected to a contact pad 131. The metal layer 129 may be electrically connected to a second capacitor contact pad 137. For example, the second capacitor contact pad 137 may be electrically connected to the readout circuit 130 as described above. The contact pad 131 and the second capacitor contact pad 137 may be disposed on the carrier 103. For example, the light-emitting semiconductor device of FIG. 6A may implement a light-emitting diode. The electromagnetic radiation 15 generated by the light-emitting diode may be output through the first main surface of the second semiconductor layer 120, for example, through the second contact layer 138.

[0060] FIG. 6B shows a cross-sectional view of a light-emitting semiconductor device 10 according to a further embodiment. The light-emitting semiconductor device 10 of FIG. 6B is a VCSEL (vertical cavity surface emitting laser).

[0061] The light-emitting semiconductor device 10 in FIG. 6B includes a first semiconductor layer 110 of a first conductivity type, a second semiconductor layer 120 of a second conductivity type, and an active zone 115 disposed between the first semiconductor layer 110 and the second semiconductor layer 120. A second contact layer 138, which can be made of a transparent material such as ITO, may be disposed on the side of the second semiconductor layer 120 opposite to the first semiconductor layer 110. The second resonator mirror 112 is disposed on the side of the second contact layer 138 opposite to the semiconductor laminate. The second contact pad 135 is electrically connected to the second contact layer 138. A first resonator mirror 111 may be disposed on the side of the first semiconductor layer 110 opposite to the active zone 115. A first contact layer 127 may be disposed on the surface of the first resonator mirror 111 on the side opposite to the semiconductor laminate. For example, the first contact layer 127 may be made of a transparent material. The horizontal width of the first contact layer 127 corresponds to the opening 121 of the light-emitting semiconductor device 10. The electromagnetic radiation 115 emitted by the light-emitting semiconductor device 10 may be output through the opening 121.

[0062] An optical resonator can be formed between the first resonator mirror 111 and the second resonator mirror 112. As an example, the first resonator mirror 111 and the second resonator mirror 112 can be realized as distributed Bragg reflectors. For example, each of the first resonator mirror 111 and the second resonator mirror 112 may include a plurality of alternating thin layers having different refractive indices. The thin layers may be formed from a semiconductor or an insulating material. For example, a layer may have a layer with a relatively low refractive index after a layer with a relatively high refractive index. The terms "relatively high" and "relatively low" may mean that the relatively high refractive index is greater than a threshold value. The relatively low refractive index may be less than the threshold value. The threshold value may depend on whether the material of the thin layer is a semiconductor or an insulating material. For example, when the material is a semiconductor material, the threshold value may be 3.1. When the material is an insulating material, the threshold value may be 1.7.

[0063] For example, the layer thickness may be λ / 4 or an integer multiple of λ / 4, where λ corresponds to the wavelength of electromagnetic radiation in each material. The first resonator mirror or the second resonator mirror may include, for example, 2 to 50 single layers. A typical layer thickness of a single layer may be 30 to 150 nm, for example, about 50 nm. The mirror laminate may further include two or more layers having a thickness greater than about 180 nm, for example, greater than about 200 nm.

[0064] When the second resonator mirror 112 is made of a semiconductor layer, the second contact layer 138 may be disposed on the side of the second resonator mirror 112 opposite to the semiconductor laminate. The first contact layer may be electrically connected to the contact pad 131 via the current diffusion layer 125. The current diffusion layer 125 may be insulated from the first semiconductor layer 110 and the second semiconductor layer 120 by the passivation layer 126. The dielectric layer 128 may be disposed on a part of the current diffusion layer 125. The metal layer 129 may be disposed on the dielectric layer 128. The capacitor 118 may include the metal layer 129, the dielectric layer 128, and the current diffusion layer 125.

[0065] The readout circuit 130 described above may be electrically connected to the metal layer 129 via the wiring 122 and the second capacitor contact pad 137. The contact pad 131 electrically connected to the current diffusion layer 125 and the second contact pad 135 electrically connected to the second semiconductor layer may be connected to each terminal via the wiring 122.

[0066] FIG. 6C shows a top view of the light-emitting semiconductor device 10 shown in FIG. 6B. For example, the components of the light-emitting semiconductor device 10 may be patterned in a circular shape.

[0067] FIG. 7 is a diagram summarizing the method according to the embodiment. A semiconductor laminate including a first semiconductor layer of a first conductivity type, an active zone for generating electromagnetic radiation, and a second semiconductor layer of a second conductivity type, a current diffusion layer on the surface of the semiconductor laminate electrically connected to the first semiconductor layer, a metal layer disposed so as to face at least a part of the current diffusion layer, and a dielectric layer between the current diffusion layer and the metal layer. A method for determining the temperature of a light-emitting semiconductor device includes determining (S100) the capacitance of a capacitor including the metal layer, the dielectric layer, and the current diffusion layer. The method further includes determining (S110) the temperature of the semiconductor laminate based on the determined capacitance.

[0068] The metal layer may include at least two regions arranged along the horizontal direction and insulated from each other. The method may further include determining (S120) the spatial distribution of the temperature of the semiconductor laminate based on the determined capacitances of a first capacitor including a first region of the metal layer and a second capacitor including a second region of the metal layer.

[0069] FIG. 8A shows a schematic diagram of a projection device 40 according to the embodiment. The projection device 40 includes the light-emitting semiconductor device 10 as described above, or the optoelectronic component 30 as described above with reference to FIGS. 4C and 4D. For example, the projection device 40 may include a plurality of light-emitting semiconductor devices 10 that emit light of different wavelengths. According to a further embodiment, the projection device 40 may include an optoelectronic component 30 having a plurality of ridges each emitting at a different wavelength. The projection device 40 may be configured to generate a full-color image. For example, when the light-emitting semiconductor device 10 or the optoelectronic component 30 further includes a driver 120 configured to control current supply depending on the detected temperature in the manner described above, the performance of the projection device 40 can be improved.

[0070] FIG. 8B shows a schematic diagram of an electronic device 50 according to an embodiment. The electronic device 50 may include the light-emitting semiconductor device 10 as described above, or the optoelectronic component 30 as described above with reference to FIGS. 4C and 4D. According to a further embodiment, the electronic device 50 may include a projection device 40 as shown in FIG. 8A. For example, the electronic device 50 may be selected from a computer, a laptop, a smartphone, a laser scanner, a LIDAR system, and further laser applications.

[0071] As described above, embodiments of the present invention have been described, but it is obvious that further embodiments may be implemented. For example, further embodiments may include any partial combination of the features described in the claims, or any partial combination of the elements described in the above examples. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments included in this specification.

Description of Reference Numerals

[0072] 10 Light-emitting semiconductor device 15 Electromagnetic radiation 20, 201, 202, 203 Light-emitting element 30 Optoelectronic component 40 Projector 50 Electronic device 100 Semiconductor substrate 103 Carrier 105 Semiconductor laminate 110 First semiconductor layer 111 First resonator mirror 112 Second resonator mirror 115 Active zone 116 Ridge 118, 1181, 1182, 1183 Capacitor 120 Second semiconductor layer 121 Opening 122 Wiring 125 Current diffusion layer 126 Passivation layer 127 First contact layer 128 dielectric layer 129, 1291, 1292, 129 i metal layer 130 readout circuit 131 contact pad 132 via contact 133 first terminal 134 second terminal 135 second contact pad 136 switch 137 second capacitor contact pad 138 second contact layer 140, 1401, 1402, 140 n driver 150 central controller 151 capacitance-voltage converter 152 sample-and-hold circuit 153 analog-digital converter 154 voltage-temperature converter 155 memory

Claims

1. A semiconductor laminate (105) including a first semiconductor layer (110) of a first conductivity type, an active zone (115) for generating electromagnetic radiation, and a second semiconductor layer (120) of a second conductivity type; A current diffusion layer (125) on the surface of the semiconductor laminate (105) electrically connected to the first semiconductor layer (110); A dielectric layer (128) on the current diffusion layer (125); A metal layer (129) disposed so as to face at least a part of the current diffusion layer (125), wherein the dielectric layer (128) is disposed between the current diffusion layer (125) and the metal layer (129); A readout circuit (130) electrically connectable to the metal layer (129) and configured to read out the capacitance between the metal layer (129) and the current diffusion layer (125); A light-emitting semiconductor device (10) including the above.

2. The metal layer (129) includes a first region and a second region (129 １ , 129 ２ ) that are arranged along the horizontal direction and insulated from each other. The light-emitting semiconductor device (10) according to Claim 1.

3. The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as an edge-emitting laser. The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as an edge-emitting laser.

4. The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as a VCSEL (Vertical Cavity Surface Emitting Laser). The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as a VCSEL (Vertical Cavity Surface Emitting Laser).

5. The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as an LED (Light-Emitting Diode). The light-emitting semiconductor device (10) according to Claim 1 or 2, realized as an LED (Light-Emitting Diode).

6. The semiconductor laminate (105) is patterned to form a ridge (116), and the current diffusion layer (125) is disposed on the first main surface of the ridge (116). The light-emitting semiconductor device (10) according to any one of Claims 3 to 5.

7. The readout circuit (130) is further configured to determine the temperature of the semiconductor laminate (105). The light-emitting semiconductor device (10) according to any one of Claims 1 to 6.

8. The metal layer (129) includes at least two regions (129 １ , 129 ２ ) that are arranged along the horizontal direction and insulated from each other. The readout circuit (130) is based on a first capacitance between a first portion of the metal layer (129 １ ) and the current diffusion layer (125), and further based on a second capacitance between a second portion of the metal layer (129 ２ ) and the current diffusion layer (125), and is configured to determine the spatial distribution of the temperature. The light-emitting semiconductor device (10) according to Claim 7.

9. Further including a driver (140) configured to supply current to the current diffusion layer (125), wherein the driver (140) is connectable to the readout circuit (130) and configured to change the current according to the capacitance read by the readout circuit (130). The light-emitting semiconductor device (10) according to any one of claims 1 to 8.

10. A semiconductor laminate (105) including a first semiconductor layer (110) of a first conductivity type, an active zone (115) for generating electromagnetic radiation, and a second semiconductor layer (120) of a second conductivity type, the semiconductor laminate (105) being patterned into a plurality of ridges (116), A plurality of current diffusion layers (125) disposed on a first main surface of the ridge (116) and electrically connected to the first semiconductor layer (110) in each of the ridges (116), A dielectric layer (128) on the current diffusion layer (125), A section of a metal layer (129) disposed so as to face a corresponding one of the current diffusion layers (125), the dielectric layer (128) being disposed between the current diffusion layer (125) and the section of the metal layer (129), the section of the metal layer (129), A readout circuit (130) electrically connectable to the section of the metal layer (129) and configured to read out a capacitance between the section of the metal layer (129) and the corresponding current diffusion layer (125), An optoelectronic component (30) comprising.

11. The readout circuit (130) is further configured to determine the temperature of the corresponding ridge (116). The optoelectronic component (30) according to claim 10.

12. Further comprising a driver (120) for determining a current supplied to a corresponding one of the current diffusion layers (125), The driver (120) is connectable to the readout circuit (130) and is configured to determine a current supplied based on the temperature detected by the readout circuit (130). The optoelectronic component (30) according to claim 11.

13. A semiconductor laminate (105) including a first semiconductor layer (110) of a first conductivity type, an active zone (115) for generating electromagnetic radiation, and a second semiconductor layer (120) of a second conductivity type, A current diffusion layer (125) on the surface of the semiconductor laminate (105) electrically connected to the first semiconductor layer (110), A metal layer (129) disposed so as to face at least a part of the current diffusion layer (125), A method for determining the temperature of a light-emitting semiconductor device (10) comprising a dielectric layer (128) between the current diffusion layer (125) and the metal layer (129), determining the capacitance of a capacitor (118) comprising the metal layer (129), the dielectric layer (128), and the current diffusion layer (125); determining the temperature of the semiconductor laminate (105) based on the determined capacitance; A method comprising.

14. The metal layer (129) includes a first region and a second region (129 １ , 129 ２ ) that are arranged along the horizontal direction and insulated from each other, and the method further includes determining a spatial distribution of the temperature of the semiconductor laminate (105) based on the determined capacitances of a first capacitor (118 １ ) that includes the first region of the metal layer (129 １ ) and a second capacitor (118 ２ ) that includes the second region of the metal layer (129 ２ ). The method according to claim 13.

15. A semiconductor laminate (105) comprising a first semiconductor layer (110) of a first conductivity type, an active zone (115) that generates electromagnetic radiation, and a second semiconductor layer (120) of a second conductivity type; A current diffusion layer (125) on the surface of the semiconductor laminate (105) electrically connected to the first semiconductor layer (110); A metal layer (129) disposed so as to face at least a part of the current diffusion layer (125); A dielectric layer (128) between the current diffusion layer (125) and the metal layer (129), wherein the material of the dielectric layer (128) is BaTiO ３ , PbMgNbO ３ , PbTiO ３ , PbLaZrTiO ３ , BaSrTiO ３ , TiO ２ , Ta ２ O ５ , CeO ２ , and, BaZrTiO ３ , SiO ２ , Si ３ N ４ , SrTiO ３ , PrScO ３ , SmScO ３ , SrTiO ３ , TbScO ３ , DyScO ３ , LiNbO ３ selected from, the dielectric layer (128), A light-emitting semiconductor device (10) comprising.

16. A projection device (40) comprising the light-emitting semiconductor device (10) according to any one of claims 1 to 9 and 15 or the optoelectronic component (30) according to any one of claims 10 to 12 Comprising.

17. The light-emitting semiconductor device (10) according to any one of claims 1 to 9 and 15, the projection device (40) according to claim 16, or the optoelectronic component (30) according to any one of claims 10 to 12, An electronic device (50) comprising.

18. Selected from a computer, laptop, smartphone, laser scanner, and LIDAR system, The electronic device (50) according to claim 17.

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