Method for producing a semiconductor device and semiconductor device

Abstract

A method for producing a semiconductor device may include applying one or more semiconductor components onto a device body where the device body has a substrate and an integrated circuit. The semiconductor component(s) may include an active zone configured to receive radiation. The method may further include transferring a multitude of semiconductor components from a sacrificial wafer to a target wafer with the device bodies still coupled by using a stamp to place them onto said device bodies. The stamp may be pressed onto the semiconductor components to adhere to the semiconductor components to the stamp and transfer them. As soon as the stamp moves in the opposite direction, the semiconductor component(s) may be separated from holding structures by breaking away webs or their projections on the second semiconductor body and leaving a breaking point directly on an outside of the semiconductor component.

Claims

1. A method for manufacturing a semiconductor device, wherein the method comprises: separating a multitude of semiconductor components from holding structures of a sacrificial wafer comprising the semiconductor components by pressing a stamp onto the semiconductor components to adhere to the semiconductor components and by breaking away webs or their attachments to the semiconductor components by moving the stamp into a direction away from the sacrificial wafer, leaving a breaking point directly on an outside of the semiconductor component, wherein each semiconductor component comprises an active zone configured to receive radiation; transferring the multitude of semiconductor components from the sacrificial wafer to a target wafer comprising a plurality of device bodies coupled to each other, each device body comprising a substrate and an integrated circuit; simultaneously placing the multitude of semiconductor components onto the plurality of device bodies by micro-transfer printing, such that the semiconductor components are coupled to the device bodies; and arranging a diffuser or a refractive layer on the one or more semiconductor components.

2. A semiconductor device comprising: a device body comprising a substrate and an integrated circuit, a first and a second semiconductor component, wherein each semiconductor component comprises an active zone configured to receive radiation and a breaking point, wherein each semiconductor component is arranged on the device body, wherein each semiconductor component is electrically conductively coupled to the integrated circuit, and wherein a sensitive spectral range of the first semiconductor component differs from that of the second semiconductor component; and a diffuser or a refractive layer arranged on the one or more semiconductor components.

3. The semiconductor device according to claim 2, wherein the semiconductor component or the plurality of semiconductor components was applied to the device body by micro-transfer printing.

4. The semiconductor device according to claim 2, wherein a material system of a first semiconductor component of the plurality of semiconductor components differs from that of a second semiconductor component of the plurality of semiconductor components.

5. The semiconductor device according to claim 4, wherein the different material systems comprise at least one of the group comprising silicon, germanium, III-V compounds, and II-IV compounds.

6. The semiconductor device according to claim 2, wherein the substrate of the device body comprises silicon.

7. The semiconductor device according to claim 2, wherein the device body comprises a transimpedance amplifier, an evaluation unit, or combinations thereof.

8. The semiconductor device according to claim 2, further comprising a layer that absorbs in a given wavelength range and is arranged on the semiconductor component or the plurality of semiconductor components or is applied to a detection region of the semiconductor component or to a detection region of at least one of the plurality of semiconductor components.

9. The semiconductor device according to claim 2, wherein a first set of semiconductor components of the plurality of semiconductor components is arranged in a first cell, wherein a second set of semiconductor components of the plurality of semiconductor components is arranged in a second cell, wherein at least the first cell and the second cell form an array of cells.

10. The semiconductor device according to claim 9, wherein the semiconductor components within the first cell or the second cell differ in their sensitive spectral ranges.

11. The semiconductor device according to claim 2, further comprising at least one active zone configured to generate radiation.

12. The semiconductor device according to claim 11, further comprising a further radiation-emitting semiconductor component or a plurality of further radiation-emitting semiconductor components, wherein further radiation-emitting semiconductor component comprises an active zone configured to generate radiation and a breaking point and is arranged on the device body and is electrically conductively coupled to the integrated circuit.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Non-limiting embodiments are illustrated below with reference to the drawing in the following figures.

(2) FIG. 1 schematically shows an exemplary embodiment of a semiconductor device in sectional view.

(3) FIGS. 2A and 2B illustrate steps in micro-transfer printing on the basis of intermediates.

(4) FIG. 3 schematically shows a further exemplary embodiment of a semiconductor device in plan view.

(5) FIG. 4 schematically shows a further exemplary embodiment of a semiconductor device in sectional view.

(6) FIG. 5 schematically shows a further exemplary embodiment of a semiconductor device in sectional view.

(7) FIG. 6A schematically shows a further exemplary embodiment of a semiconductor device in sectional view.

(8) FIGS. 6B and 6C illustrate the filtering effect of the exemplary embodiment of a semiconductor device.

(9) FIG. 7 schematically shows an exemplary embodiment of a semiconductor component.

(10) FIG. 8 illustrates the wavelength-dependent absorption behavior of the semiconductor component.

(11) FIG. 9 schematically shows a further exemplary embodiment of a semiconductor device in sectional view.

(12) Identical, similar or equivalently functioning elements are labelled with identical reference signs in the figures. The figures are all schematic representations and therefore not necessarily true to scale. Rather, comparatively small elements and, in particular, layer thicknesses can be displayed excessively large for clarity.

DETAILED DESCRIPTION

(13) FIG. 1 schematically shows an exemplary embodiment of a semiconductor device in sectional view.

(14) The semiconductor device 1 comprises a device body 3 and a plurality of semiconductor components 5 arranged on the device body 3.

(15) The device body 3 comprises a substrate 7 with an integrated circuit 9. In this exemplary embodiment, it is embodied as an application-specific integrated circuit (ASIC) on a silicon substrate, Si ASIC for short. Such a device body 3 may comprise a logic gate. It can serve as transimpedance amplifier or evaluation unit or provide functions of such assemblies. The integrated circuit is electrically conductively coupled to the semiconductor components 5.

(16) Each of the plurality of semiconductor components 5 comprises an active zone for receiving radiation so that it is suitable as a photodetector. The semiconductor component 5 can be designed as a photodiode of small size and thickness, which is also referred to as a microphotodiode, “μPD” for short.

(17) The plurality of semiconductor components 5 comprises various types of semiconductor components 5; in this exemplary embodiment, four are illustrated by way of example. One exemplary embodiment of photodiodes are metal-semiconductor-metal photodiodes of small size and thickness, referred to as “μMSM” for short. The photodetecting structures that can be used as semiconductor components are not limited to the above-described exemplary embodiments. The types of semiconductor components 5 differ in the wavelength range in which they detect radiation. In other words: The semiconductor components 5 differ in their sensitive spectral ranges so that the combination of various semiconductor components 5 makes it possible to form a spectrometer as a semiconductor device, the measuring range of which results from the superposition of the sensitive spectral ranges.

(18) In this exemplary embodiment, the semiconductor components 5 are printable microphotodiodes which were applied to the first semiconductor body by means of micro-transfer printing.

(19) The production of the semiconductor device 1 from a device body 3 and the semiconductor components 5 by means of this method is explained below with reference to FIGS. 2A and 2B.

(20) The production of the device body 3 takes place for a multitude of device bodies 3 simultaneously and in the wafer composite. This form of production allows process steps for the production of the multitude of device bodies 3 to be carried out in parallel in all device bodies 3 simultaneously as long as they are still coupled to one another. Such process steps comprise in particular the application or growth of layers and structures, and also their partial removal if necessary, in order to form the integrated circuit 9. The first semiconductor bodies 3 are singulated and separated from one another only in a final step.

(21) Within the framework of the production, the semiconductor components 5 are placed onto the device bodies 3 and coupled to one another in a parallel assembly process as long as said device bodies are still in the composite. This assembly takes place simultaneously by transferring by means of an elastomer stamp a multitude of semiconductor components 5 from a sacrificial wafer 52 to the target wafer 54 with the device bodies 3 still coupled and placing them onto said device bodies in such a way that the semiconductor components 5 are located at their intended positions on the device bodies 3. The stamp plate comprises a structure corresponding with the size and positions of the semiconductor components 5 on the target wafer 54.

(22) The semiconductor components 5 are likewise produced in parallel in the wafer composite. The corresponding wafer is referred to as sacrificial wafer 52. In this case, however, the second semiconductor bodies 5 are not singulated by separating the wafer 52. Rather, the second semiconductor bodies 5 are simultaneously produced on a sacrificial layer in such a way that all later semiconductor components 5 are coupled to one another via holding structures 30. The sacrificial layer is then removed so that the individual second semiconductor bodies 5 are only coupled to one another and to the wafer substrate via the holding structures 30, wherein free-standing webs 32 coupled the semiconductor components 5 to an anchor structure 34 which in turn is coupled to the wafer substrate. The semiconductor components 5 produced in this way are arranged in a grid shape in the composite.

(23) The thickness of chips produced in this way as semiconductor components 5 can be significantly lower than in the case of conventionally singulated chips and can be in the range of a few micrometers.

(24) During parallel transfer, the stamp is pressed onto the semiconductor components 5 to be transferred so that they adhere to the stamp. As soon as the stamp moves in the opposite direction, the semiconductor components 5 are separated from the holding structures 30 by the webs 32 or their projection on the second semiconductor body 2 breaking away. A breaking point 40 remains on the semiconductor component 5 and may be located on a web-shaped extension 38 which is part of the web 32 of the holding structure 30.

(25) FIG. 2A shows a schematic illustration of the sacrificial wafer 52 with a multitude of second semiconductor bodies 5 and the holding structure 30. After removal of the sacrificial layer, the second semiconductor bodies 5 are free-standing and coupled only via webs 32 to an anchor structure 34 which forms the connection between the holding structure 30 and the wafer substrate. FIG. 2B shows a schematic representation of the target wafer 54 with a multitude of first semiconductor bodies 3 in the composite. Onto each of the first semiconductor bodies 3 have already been placed two second semiconductor bodies 5, which in a manner corresponding to their position on the target wafer 54 were detached from the sacrificial wafer 52 and transferred to the target wafer 54 by means of the stamp.

(26) In the case of the detached second semiconductor body 5, the breaking point 40 is located on a web-shaped extension 38 which is part of the original web 32. Alternatively, the breaking point 40 may also be located directly on an outside of the semiconductor component 5.

(27) In the parallel assembly process, a multitude of semiconductor components 5 is simultaneously transferred by breaking them out of the sacrificial wafer 52 upon contact with the stamp and depositing them on the target wafer 54 after transfer. Further process steps may then be carried out at the wafer level.

(28) The parallel transfer reduces the costs in comparison to serial assembly. The parallel assembly process described above is also referred to as micro-transfer printing. The use of printable microphotodiodes as semiconductor components 5 makes it possible to achieve a high packing density during the wafer-level assembly.

(29) FIG. 3 schematically shows a further exemplary embodiment of a semiconductor device in plan view.

(30) The semiconductor device 1 comprises a plurality of semiconductor components 5 on a device body 3 as described, for example, in connection with FIG. 1.

(31) The semiconductor components 5 are arranged in unit cells 55 arranged in an array of rows and columns. Each unit cell 55 comprises the same types of semiconductor components 5 in a predetermined arrangement with respect to one another. In this exemplary embodiment, a unit cell 55 comprises four different types of semiconductor components 5 arranged in two columns and two rows as a detector array or unit cell array.

(32) The unit cells 55 are also arranged in an array. FIG. 3 shows by way of example four cells 55 in two columns and two rows. The unit cell array can be replicated on the smart substrate 7 for the purpose of better mixing.

(33) The types of semiconductor components 5 in each unit cell 5 differ in their reception characteristics. The superposition of the sensitive spectral ranges of the semiconductor components 5 in the cell 5 results in their measuring range.

(34) The types of semiconductor components 5 may be formed from different material systems, e.g., silicon, germanium, indium phosphide, a III-V compound, or a II-IV compound.

(35) The combination of various material systems for the semiconductor components 5 in the same semiconductor device 1 enables numerous degrees of freedom in adjusting the sensitive spectral ranges for the various semiconductor components 5. In addition, the sensitive spectral range can be further influenced by bandgap engineering so that only a narrow wavelength range is detected by means of a semiconductor component 5. The combinations of various narrow sensitive spectral ranges allow the construction of an efficient spectrometer semiconductor device with very good measurement accuracy.

(36) An alternative or additional means of forming different sensitive spectral ranges is the at least partial use of color filters applied to at least some of the semiconductor components 5.

(37) The array of unit cells 55 allows for spatial resolution in detection since each cell 5 is suitable for detecting the spectrum of light incident in its range. Alternatively, it is possible to achieve better mixing of the incident light by using several cells 55 instead of only a few large-area photodiodes for various wavelengths since the detection of only local maxima or minima is avoided by averaging over several cells 55.

(38) FIG. 4 schematically shows a further exemplary embodiment of a semiconductor device in sectional view. In order to avoid repetitions, only the differences from the exemplary embodiment shown in FIG. 1 are described.

(39) The semiconductor device 1 comprises a device body 3 and a plurality of semiconductor components 5. In this exemplary embodiment, eight different types of microphotodiodes, the sensitive spectral ranges of which differ, are provided as semiconductor components 5.

(40) A diffuser optical system 13 is provided on the semiconductor components 5 and enables a more homogeneous illumination of the various types of microphotodiodes as semiconductor components 5 and thus increases the detection accuracy.

(41) It should be noted that the various types of semiconductor components 5 below the diffuser optical system 13 may also be arranged in an array of unit cells 55 as described above.

(42) FIG. 5 schematically shows a further exemplary embodiment of a semiconductor device 1 in sectional view. In order to avoid repetitions, only the differences from the exemplary embodiment shown in FIG. 1 are described.

(43) In this exemplary embodiment, the plurality of semiconductor components 5 comprises replicating detector cells 55 having semiconductor bodies 5 of two types. On the semiconductor components 5 is provided an imaging optical system 16 which has the effect of a lens and directs the incident light onto the semiconductor components 5. The spatial resolution by the plurality of cells makes it possible to detect the direction of the incident light. This arrangement uses various types of microphotodiodes (as opposed to LIDAR or ToF applications with identical microphotodiodes).

(44) It should be noted that the various types of semiconductor components 5 below the optical system 16 may also be arranged in an array of cells 55 having rows and columns as previously described.

(45) FIGS. 6A, 6B, and 6C illustrate the filtering effect of an exemplary embodiment of a semiconductor device 1 having various microphotodiodes as semiconductor components 5, as shown in FIG. 1. However, six different types of semiconductor components 5 are illustrated by way of example in this exemplary embodiment in FIG. 6A. More or fewer types as well as their arrangement in an array of cells are conceivable. The filtering effect of the other previously described exemplary embodiments follows the same principle.

(46) FIG. 6B shows by way of example the sensitivity of the microphotodiodes as semiconductor components 55 over the wavelength. Each of the microphotodiodes shown in FIG. 6A detects in a wavelength range different from that of the others, but the combination of the various microphotodiodes and the superposition of their sensitive spectra covers the entire spectrum in which detection is to take place. In this exemplary embodiment, the spectra do not overlap.

(47) FIG. 6C shows by way of example the sensitivity of the microphotodiodes over the wavelength in an exemplary embodiment different from the previous one in that the spectra at least partially overlap.

(48) FIG. 7 shows an exemplary embodiment of a wavelength-selective photodiode printable by means of micro-transfer printing as semiconductor component 5, the sensitive spectral range of which was adjusted by bandgap engineering.

(49) The semiconductor component 5 comprises a substrate 7 and a first contact 21 on its upper side and a second contact 22 on its underside. These contacts 21, 22 may be n- or p-contacts. On the substrate upper side is provided a detection region 8 with the active zone 11 in which the incident light 100 is detected. A wavelength-selective layer 25 is applied to the detection region 8. By combining two materials, bandgap engineering can be achieved, for example, as follows: The detection region 8 is suitable for detecting radiation below a specific wavelength, referred to as Y by way of example. An absorption layer 25 absorbs radiation below a specific wavelength, referred to as X by way of example, so that this radiation no longer reaches the active zone 11. Consequently, only radiation in the wavelength range between Y and X is absorbed in the active zone 11 since radiation above the range cannot be detected and radiation below the range does not reach the detection region 8.

(50) FIG. 8 illustrates the absorption behavior described above with reference to a representation of the absorption as a function of the wavelength. Although the wavelength range 101 below the wavelength Y can be detected in the detection region 8, only the difference range 103 between the wavelengths X and Y is detected and absorbed because of the shading of the radiation in the wavelength range 102 up to the wavelength X. The sensitivity of a semiconductor component 5 and its sensitive spectral range can be adjusted in a targeted manner by suitably combining various materials.

(51) Various material combinations allow different sensitivities, which can be combined to form a spectrometer.

(52) FIG. 9 schematically shows a further exemplary embodiment of a semiconductor device in sectional view.

(53) The semiconductor device 1 comprises a plurality of semiconductor components 5 on a device body 3 as described, for example, in connection with FIG. 1. In order to avoid repetitions, only the differences to FIG. 1 are described.

(54) In addition to the microphotodiodes 5, this exemplary embodiment also comprises radiation-emitting semiconductor components 6 in order to form a sensor. Each radiation-emitting semiconductor component 6, which may be formed, for example, as LEDs, comprises an active zone for generating radiation and a breaking point, is arranged on the substrate, and is electrically conductively coupled to the device body 3. The radiation-emitting semiconductor components 6 are also printable components which were applied to the device body 3 by means of the micro-transfer printing described above.

(55) The features of the exemplary embodiments can be combined. The invention is not limited by the description based on the exemplary embodiments. Rather, the invention comprises any new feature and any combination of features, which in particular comprises any combination of features in the claims, even if this feature or combination itself is not explicitly specified in the claims or exemplary embodiments.

LIST OF REFERENCE SIGNS

(56) 1 Semiconductor device 3 Device body 5 Semiconductor component 7 Substrate 8 Detection region 9 Integrated circuit 11 Active zone 13 Diffuser optical system 16 Optical system 21, 22 Contact 25 Absorption layer 30 Holding structure 32 Web 34 Anchor structure 38 Extension 40 Breaking point 52 Sacrificial substrate 54 Target substrate 55 Cell 100 Light 101, 102, 103 Range X, Y Wavelength