METHOD FOR MANUFACTURING AN OPTOELECTRONIC DEVICE

Description

Domaine technique

[0001] This description relates generally to the field of optoelectronic devices, and more specifically to a manufacturing process for an optoelectronic device combining a light emission function and an optical capture function. Technique antérieure

[0002] Various applications can benefit from an optoelectronic device that combines a light emission function and an optical capture function. Such a device can, for example, be used to create an interactive display screen. Summary of the invention

[0003] An object of an embodiment is to overcome all or part of the disadvantages of known solutions for realizing an optoelectronic device combining a light emission function and an optical capture function.

[0004] To this end, one embodiment provides a method for manufacturing an optoelectronic device as described in claim 1.

[0005] According to one embodiment, the process comprises the formation of a plurality of photosensitive diodes in the active stack of photosensitive diodes.

[0006] According to one embodiment, in step a), the active stack of photosensitive diodes is fixed to the control integrated circuit by direct bonding of a dielectric layer previously deposited on the active stack of photosensitive diodes, with a dielectric layer previously deposited on the control integrated circuit.

[0007] According to one embodiment, the process includes, after step b), the formation of optical filters or color conversion elements above the organic light-emitting diodes.

[0008] According to one embodiment, the organic light-emitting diodes are monochromatic diodes of the same color, at least one of said organic light-emitting diodes being surmounted by a photoluminescent conversion element adapted to convert the light emitted by the diode to a first visible wavelength and at least another of said organic light-emitting diodes being surmounted by a photoluminescent conversion element adapted to convert the light emitted by the diode into light radiation in the range of wavelengths detected by said at least one inorganic photosensitive diode, preferably infrared radiation.

[0009] According to one embodiment, at least one of said organic light-emitting diodes is not surmounted by a photoluminescent conversion element.

[0010] According to one embodiment, organic light-emitting diodes are adapted to emit predominantly blue light.

[0011] According to one embodiment, the photoluminescent conversion elements are made from quantum dots or perovskite materials.

[0012] According to one embodiment, the active stack of photosensitive diodes comprises at least one semiconductor layer in a III-V material.

[0013] According to one embodiment, said P-type doping step of localized portions of the first layer is carried out after step a) and before step b).

[0014] According to one embodiment, the process further comprises, after said P-type doping step of localized portions of the first layer and before step b), a step of forming connection metallizations on and in contact with said localized portions of the first layer.

[0015] According to one embodiment, the method comprises, after step b), a step of fixing a temporary support substrate to the side of a face of the device opposite the integrated circuit, followed by a step of cutting the assembly comprising the integrated circuit, the active stack of photosensitive diodes and the organic light-emitting diodes into a plurality of elementary chips.

[0016] According to one embodiment, the process further comprises a step of transferring and fixing said elementary chips onto a substrate for transferring the device, and then a step of removing the temporary support substrate.

[0017] One embodiment provides an optoelectronic device as described in claim 14.

[0018] Another embodiment provides for a system comprising an optoelectronic device as defined above, and a light source adapted to emit light radiation in the range of wavelengths detected by the inorganic photosensitive diode, preferably infrared radiation.

[0019] According to one embodiment, the light source is a remote source.

[0020] According to one embodiment, the light source is integrated into the optoelectronic device and includes at least one organic light-emitting diode from the emission stage of the optoelectronic device. Brève description des dessins

[0021] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the attached figures, among which: THE figures 1A, 1B, 1C , 1D, 1E, 1F , 1G, 1H et 1I are cross-sectional views illustrating successive stages of an example of a manufacturing process for an optoelectronic device according to a given embodiment; figures 2A, 2B, 2C, 2D , 2E, 2F, et 2G are cross-sectional views illustrating further successive steps in an example of a manufacturing process for an optoelectronic device according to one embodiment; the figure 3 schematically represents an example of a system comprising an optoelectronic device according to one embodiment; and the figure 4 is a cross-sectional view schematically and partially illustrating another example of an optoelectronic device according to one embodiment. Description des modes de réalisation

[0022] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0023] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and are detailed. In particular, the fabrication of the photosensitive diodes, light-emitting diodes (LEDs), and integrated circuits for controlling the described devices has not been detailed, as the detailed fabrication of these components is within the grasp of a person skilled in the art based on the information provided in this description. Furthermore, the various applications of the described devices have not been detailed, as the described embodiments are compatible with all or most applications that could benefit from a device combining a light emission function and an optical capture function (photodetection).

[0024] Unless otherwise specified, when referring to two connected elements, this means directly connected without any intermediate elements other than conductors, and when referring to two coupled elements, this means that these two elements can be connected or linked through one or more other elements.

[0025] In the description that follows, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative positional qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientational qualifiers, such as the terms "horizontal", "vertical", etc., unless otherwise specified, reference is made to the orientation of the corresponding figures.

[0026] Unless otherwise specified, the expressions "approximately", "roughly", and "on the order of" mean within 10%, preferably within 5%.

[0027] According to one aspect of an embodiment, an optoelectronic device combining a light-emitting function and a photodetection function is constructed by transferring an active stack of inorganic photosensitive diodes onto a control integrated circuit previously formed in and on a semiconductor substrate, and then forming a plurality of organic LEDs on the active stack of photosensitive diodes. The method further comprises, after transferring the active stack of inorganic photosensitive diodes and before forming the organic LEDs, the formation of conductive vias through the stack of photosensitive diodes, enabling the electrical connection of the active stack of photosensitive diodes and the organic LEDs to the control integrated circuit.

[0028] THE figures 1A à 1I These are cross-sectional views illustrating successive stages of a non-limiting example of implementing such a process. Various variations are within the reach of a person skilled in the art, based on the information provided in this description.

[0029] For the sake of simplicity, we have represented on the figures 1A à 1I the realization of a device comprising a single photosensitive diode D1 and three organic LEDs L1, L2, L3. In practice, the processes described can of course be used to make devices comprising a much larger number of photosensitive diodes and organic LEDs.

[0030] There figure 1A The upper portion of the diagram schematically illustrates a control integrated circuit 151 formed in and on a semiconductor substrate, for example, a monocrystalline silicon substrate. The integrated circuit 151 includes control and readout circuits for the LEDs and photodiodes of the device. For example, the integrated circuit 151 includes a set of elementary control and readout cells, allowing each LED to be individually controlled and each photodiode of the device to be individually read. The integrated circuit 151 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) circuit. In this example, the circuit 151 includes a plurality of metallic connection pads 153 arranged on its upper surface, intended to be connected respectively to the anodes and cathodes of the LEDs and photodiodes of the device.As an example, the 153 pads are flush with the top face of an interconnect stack (not detailed in the figure) covering the top face of the semiconductor substrate of the circuit.

[0031] There figure 1A It also schematically illustrates, in the lower part, the structure obtained after the steps of forming an active stack of photosensitive diode 103 on the upper face of a substrate 101.

[0032] The 103 stack is a stack of inorganic semiconductor layers. The 103 stack may, for example, include one or more layers of a type III-V semiconductor material. The 103 stack can be, for example, an active stack of photodiodes sensitive in the infrared or near-infrared. Alternatively, the 103 stack can be an active stack of photodiodes sensitive in the visible spectrum. As an example, the 103 stack comprises, in order from the top face of the substrate 101, an unintentionally doped indium phosphide (InP) layer 103a, an absorption layer 103b of indium gallium arsenide (InGaAs), for example intrinsic or weakly doped of type N (for example on the order of 10 15< atoms / cm 3< ), and an N-type doped indium phosphide (InP) layer 103c. As an example, the N-type doping level of the 103c layer is between 10 16< and 10 18< atoms / cm 3< .In this example, layer 103b is in contact, by its lower face, with the upper face of layer 103a, and layer 103c is in contact, by its lower face, with the upper face of layer 103b.

[0033] Substrate 101 is, for example, indium phosphide. Layers 103a, 103b, and 103c can be formed successively by epitaxy on the upper surface of substrate 101. Substrate 101 is then a growth substrate. A buffer layer, not shown, for example made of indium phosphide, can optionally interface between substrate 101 and layer 103a. The buffer layer is, for example, in contact, via its lower surface, with the upper surface of substrate 101, and, via its upper surface, with the lower surface of layer 103a. The buffer layer can also be formed by epitaxy from the upper surface of substrate 101, before the formation of layers 103a, 103b, and 103c.

[0034] Alternatively, instead of forming the active stack of photosensitive diodes 103 by epitaxy on the upper surface of the substrate 101, the active stack can be formed in reverse order on a growth substrate (not shown), and then transferred and fixed onto the substrate 101. In this case, layers 103c, 103b, and 103a are successively formed by epitaxy on one face of the growth substrate. A buffer layer, for example made of indium phosphide, can optionally interface between the growth substrate and layer 103c. The stack 103 is then fixed to the upper face of the substrate 101, for example by direct bonding or molecular bonding of the lower face of the layer 103a to the upper face of the substrate 101. The growth substrate, and, where applicable, the buffer layer interfacing between the growth substrate and the layer 103c, can then be removed so as to free access to the upper face of the layer 103c.In this variant, the substrate 101 is a support substrate, for example made of silicon, or any other material suitable to serve as a receiving support for the active stack 103.

[0035] At this stage, each of the layers of the active stack of photosensitive diode 103 extends, for example, continuously and with a substantially uniform thickness over the entire upper surface of the substrate 101.

[0036] There figure 1A further illustrates a step of depositing a dielectric layer 155, for example of silicon oxide, on and in contact with the top face of the control integrated circuit 151. In this example, the layer 155 extends continuously and with a substantially uniform thickness over the entire top surface of the control integrated circuit 151.

[0037] There figure 1A This further illustrates a step of depositing a dielectric layer 105, for example of the same material as layer 155, for example silicon oxide, onto the upper surface of the active stack of photosensitive diodes 103. By way of example, layer 105 is deposited on and in contact with the upper surface of layer 103c. Layer 105 extends, for example, continuously and with a substantially uniform thickness over the entire upper surface of the stack 103.

[0038] There figure 1B illustrates the structure obtained after a step of transferring and fixing the active stack of photosensitive diodes 103 onto the control integrated circuit 151, and then removing the substrate 101. During this step, the active stack of photosensitive diodes 103 is transferred onto the integrated circuit 151, using the substrate 101 as a support handle. On the figure 1B , the structure comprising the substrate 101 and the stack 103 is flipped with respect to the orientation of the figure 1A The stack-up 103 is then fixed to the control integrated circuit 151. In this example, the stack-up 103 is fixed by direct bonding or molecular bonding of the lower face (in the orientation of the figure 1B , corresponding to the upper face in the orientation of the figure 1A ) of layer 105, on the upper face of layer 155. The substrate 101 is then removed, for example by grinding and / or chemical etching, so as to provide access to the upper face of layer 103a. At this stage, each of the layers of the active stack of photosensitive diodes 103 extends, for example, continuously and with a substantially uniform thickness, over the entire surface of the control integrated circuit 151. It should be noted that in this example, the active stack 103 is unstructured and has not undergone any localized processing steps before the transfer step. Thus, the transfer step does not require precise alignment.

[0039] There figure 1C illustrates the structure obtained after the following successive steps: i) deposition of a dielectric layer 111, for example of silicon nitride or silicon oxide, on the upper face of the layer 103a, for example in contact with the upper face of the layer 103a; ii) formation of localized through-holes in the dielectric layer 111, opposite future P-type contact re-establishment areas corresponding to anode regions of the photosensitive diodes of the device; iii) P-type doping of localized regions 113 of the layer 103a, located opposite said through-holes; iv) formation of contact re-establishment metallizations 115 in the through-holes, each metallization 115 individually contacting the underlying P-type doped region 113, through the corresponding opening.

[0040] In step i), the dielectric layer 111 is for example deposited by a plasma-enhanced chemical vapor deposition (PECVD) process.

[0041] In step ii), the through-holes formed in the dielectric layer 111 are for example formed by photolithography and etching.

[0042] In step iii), the doping of regions 113 can be achieved by diffusion or implantation of P-type dopants, for example zinc (Zn) or beryllium (Be), opposite the openings formed in step ii). An activation annealing of the dopants can then be performed. For example, the activation annealing can be a surface laser annealing, which avoids altering the integrated circuit 151 or the quality of the bond between the integrated circuit 151 and the active stack of photosensitive diodes 103. The P-type doped regions 113 form the anode regions of the photosensitive diodes of the device. In this example, the regions 113 extend across the entire thickness of layer 103a and are in contact, on their lower surface, with the upper surface of the absorption layer 103b.

[0043] In step iv), by way of example, a metallic layer is first deposited continuously over the entire upper surface of the structure, i.e. on and in contact with the upper face of the dielectric layer 111 and in the openings formed in step ii), and then removed by photolithography and etching while preserving the metallizations 115. In this example, each metallization 115 constitutes an anode electrode of a photosensitive diode D1 of the device.

[0044] There figure 1D This illustrates the structure obtained after a formation step, starting from the upper face of the structure, of initial contact openings or vias 121 traversing the active stack of photosensitive diodes 103 and opening onto connection pads 153 of the control integrated circuit. The openings 121 extend vertically from the upper face of the dielectric layer 111 to the upper face of the pads 153, through layers 111, 103a, 103b, 103c, 105, and 155. The openings 121 may, for example, have a circular shape. In this example, a specific opening 121(a) is formed at this stage for each of the photosensitive diodes D1, creating an anode contact opening for the diode. In addition, for each of the LEDs L1, L2, L3, a specific opening 121(b) is formed, forming an opening for the resumption of contact of the LED anode.Furthermore, in this example, at this stage, for example in a peripheral region of the device, an opening 121(c) common to LEDs L1, L2, and L3 is formed, creating a cathode contact resumption opening for said LEDs. The openings 121(a), 121(b), and 121(c) are, for example, identical except for manufacturing variations. In this example, the openings 121(a), 121(b), and 121(c) are formed simultaneously during the same localized etching step. The openings 121(a), 121(b), and 121(c) lead respectively to separate metal pads 153 of the control integrated circuit 151, so as to allow individual control of the diodes D1, L1, L2, and L3 by the circuit 151.

[0045] There figure 1D It further illustrates a step of depositing an electrically insulating layer 123, for example of silicon oxide, onto the lateral walls of the openings 121(a), 121(b), 121(c). The layer 123 is, for example, first deposited continuously over the entire upper surface of the structure after the openings 121 have been formed. The horizontal portions of the layer 123 are then removed by vertical anisotropic etching so that only the vertical portions remain, coating the lateral walls of the openings 121.

[0046] There figure 1E illustrates the structure obtained at the end of a subsequent formation stage, from the upper face of the structure of the figure 1D , of at least one second contact resumption aperture 125 passing through the active stack of photosensitive diodes 103 and opening onto a connection pad 153 of the control integrated circuit. Like the apertures 121, the aperture 125 extends vertically from the upper face of the dielectric layer 111 to the upper face of the underlying pad 153, through layers 111, 103a, 103b, 103c, 105 and 155. The aperture 125 has, for example, the same shape as the apertures 121. In this example, at this stage, for example in a peripheral region of the device, an aperture 125 common to the photosensitive diodes D1 of the device is formed, creating a cathode contact resumption aperture for said diodes.

[0047] Unlike the openings 121, the side walls of the opening 125 are not coated with an electrically insulating layer.

[0048] There figure 1F illustrates a subsequent step of filling the openings 121(a), 121(b), 121(c) and 125 with metal, so as to form conductive vias 127(a), 127(b), 127(c), and 127(d), respectively. Following this step, a planarization step of the upper face of the structure, for example a chemical-mechanical planarization (CMP), can be implemented, so that the metallizations 115, 127(a), 127(b), 127(c), and 127(d) are flush with the upper face of the dielectric layer 111.

[0049] In this example, the vias 127(a) for anode contact of diodes D1, 127(b) for anode contact of LEDs L1, L2, L3 and 127(c) for cathode contact of LEDs L1, L2, L3, are isolated from the layers of the stack 103 by the lateral insulation layer 123. The via 127(d) for cathode contact of diodes D1 is, on the other hand, in contact, by its sides, with the semiconductor layers of the stack 103.

[0050] Via 127(d) electrically connects the cathode layer 103c of the photosensitive diode stack to a cathode connection pad 153 of the photosensitive diodes D1. It should be noted that since layers 103b and 103a of the stack 103 are lightly doped or undoped, the lateral contact between via 127(d) and these layers 103b and 103c does not cause a short circuit in the diodes D1. The doped layer 103c ensures equipotentiality over the entire surface of the device.

[0051] There figure 1G illustrates the structure obtained after a metallization formation step on the upper face of the structure of the figure 1F . The metallizations formed at this stage are in contact, by their lower face, with the upper face of the dielectric layer 111 and with underlying metallizations 127 or 115.

[0052] At this stage, for example, for each diode D1, a metallization 129 is formed electrically connecting the anode contact resumption via 127(a) of diode D1 to the anode contact metallization 115 of this diode.

[0053] Moreover, in this example, for each LED L1, L2, L3, a metallization 131 is formed extending substantially over the entire surface of the LED, corresponding to an anode electrode of the future LED, in contact, by its lower face, with an anode contact resumption via 127(b) of the LED.

[0054] Furthermore, in this example, a cathode contact recovery metallization 133 of the LEDs is formed, in contact, by its lower face, with the cathode contact recovery via 127(c) of the LEDs.

[0055] Metallizations 129, 131, and 133 are, for example, formed in the same metallic layer. As an example, a layer of metal is first deposited as a full plate over the entire upper surface of the structure of the figure 1F , then removed locally by photolithography and engraving while preserving the metallizations 129, 131 and 133.

[0056] There figure 1H illustrates the structure obtained after the formation steps of the organic LEDs L1, L2, L3 on the upper face of the structure of the figure 1G .

[0057] In this example, the organic LED formation process comprises the following successive steps: i) deposition of a passivation layer 141 on the upper face of the structure of the figure 1G , then localized opening of layer 141 opposite the metallizations 131 and 133; ii) deposition of an active layer of organic diode 143 (consisting for example of a stack of injection, transport and emission layers) on and in contact with the anode electrodes 131 of the LEDs L1, L2, L3; iii) deposition of a cathode electrode 145 of the LEDs L1, L2, L3 on and in contact with the upper face of the active layer 143; and iv) deposition of an encapsulation layer 147 on and in contact with the upper face of the electrode 145.

[0058] The layer 141 deposited in step i) is, for example, a layer made of a polymer material, such as a resin. Alternatively, the layer 141 may be made of silicon oxide. The layer 141 may be deposited as a full plate, covering the entire upper surface of the structure. figure 1G , then removed locally, for example by photolithography and etching, to expose electrodes 131 and 133. In this example, the metallizations 127(d) and 129 remain covered by layer 141. Moreover, in this example, the exposed portions of the dielectric layer 111 are completely covered by layer 141. More specifically, in this example, in top view, each of the metallizations 133 and 135 is completely surrounded and separated laterally from the other metallizations by portions of layer 141.

[0059] The active layer 143 can consist of a single layer of a photosensitive organic material, or a stack of several organic layers forming a photosensitive layer. In this example, layer 143 is a broad-spectrum emission layer, for example, a white light emission layer. In this example, layer 143 is non-pixelated, meaning it extends continuously opposite the anode electrodes 133 of the LEDs L1, L2, and L3 of the device. In the example shown, layer 143 does not extend opposite the photosensitive diodes D1 of the device. As an example, the active layer 143 can be deposited locally by evaporation through a shadow mask. The three colors are then deposited separately and successively, and there is no need for colored filters.Alternatively, layer 143 can extend continuously over substantially the entire surface of the device, particularly opposite the photosensitive diodes D1. In this case, layer 143 can be deposited on the entire board, for example, using a spin coating. Preferably, layer 143 does not cover the cathode contact electrode 133 of the LEDs.

[0060] The cathode electrode 145 extends continuously across the entire upper surface of the device. Electrode 145 is preferably made of a transparent conductive material, for example, a transparent conductive oxide such as indium tin oxide (ITO). At the periphery of the device, electrode 145 is in contact, via its lower surface, with the upper surface of the cathode contact electrode 133 of the LEDs.

[0061] The encapsulation layer 147 is designed to protect the active layer of LED 143, particularly against moisture and oxygen. Layer 147 is preferably made of a transparent, electrically insulating material, such as aluminum oxide. Layer 147 extends continuously over the entire upper surface of the device. It can be produced by atomic layer deposition (ALD).

[0062] There figure 1I illustrates the structure obtained after steps of forming filtering elements and / or color conversion on the upper face of the structure of the figure 1H .

[0063] As an example, a planarizing layer 151 made of a transparent material, for example resin, is first deposited on the upper face of the structure of the figure 1H . In this example, layer 151 is in contact, by its lower face, with the upper face of the encapsulation layer 147. Layer 151 has a substantially flat upper face.

[0064] In this example, an optical filter 163 is placed opposite the photosensitive diode D1, and optical filters 165-1, 165-2, and 165-3 are placed opposite the LEDs L1, L2, and L3, respectively. Filter 163 is suitable for blocking visible light and allowing mostly infrared light to pass through. It should be noted that filter 163 can be replaced by, or combined with, an optical element for shaping the incident light, such as a microlens. Filters 165-1, 165-2, and 165-3 are suitable for allowing mostly visible light to pass through in three distinct wavelength ranges, respectively. For example, filters 165-1, 165-2, and 165-3 are suitable for allowing mostly red, green, and blue light to pass through. Filters 163, 165-1, 165-2, 165-3 are, for example, resin filters.As an alternative, filters 165-1, 165-2, and 165-3 can be replaced by photoluminescent color conversion elements. For example, active layer 143 is a monochromatic emission layer, such as a blue light emission layer. In this case, elements 165-1 and 165-2 are, for example, a photoluminescent conversion element adapted to convert the blue light emitted by active layer 143 into red light, and a photoluminescent conversion element adapted to convert the blue light emitted by active layer 143 into green light, respectively. In this configuration, element 165-3 can be omitted. LEDs L1, L2, and L3 thus define three emission pixels adapted to emit red, green, and blue light, respectively.

[0065] Thus, we obtain a device comprising one or more detection pixels, each containing a photosensitive diode D1 based on an inorganic semiconductor material, and one or more emission pixels, each containing an organic LED L1, L2, L3, the entire set of detection and emission pixels being controlled by the same integrated control circuit.

[0066] It should be noted that, in the example described above, the organic active layer 143 is common to the different emitting pixels of the device, with color differentiation ensured by filters or color conversion elements opposite the organic LEDs of the different pixels. Alternatively, organic active layers of distinct types can be incorporated into the organic LEDs of the different pixels, so as to create LEDs L1, L2, L3 emitting directly in distinct wavelength ranges. In this case, filters 165-1, 165-2, and 165-3 can be omitted.

[0067] Furthermore, the described embodiments are not limited to the specific example described above of a device comprising three distinct types of emitting pixels adapted to emit in three distinct wavelength ranges. As an alternative, the device may comprise two or more than four emitting pixels emitting in distinct wavelength ranges. In another alternative, the device may be monochromatic in emission, that is, comprise a single type of emitting pixel. In this case, the color conversion filters or elements 165-1, 165-2, and 165-3 may be omitted.

[0068] Furthermore, in the example described above, the device is monochromatic in reception, meaning it comprises a single type of detection pixel, sensitive within a specific wavelength range. Alternatively, the device may include several types of detection pixels adapted to measure radiation in distinct wavelength ranges. The differentiation of these wavelength ranges can then be achieved using filters 163 of different types opposite the various detection pixels. In another variant, the optical filters 163 can be omitted in the case of a monochromatic receiving device.

[0069] Furthermore, in the example described above, the cathode contact resumption via 127(d) of the photosensitive diodes D1 is common to all the diodes D1. As an alternative, the device may include a specific cathode contact resumption via 127(d) for each photosensitive diode D1.

[0070] Similarly, in the example described above, the cathode electrode 145 and the cathode reconnect via 127(c) are common to the various LEDs L1, L2, L3 of the device. Alternatively, the device may include a specific cathode electrode 145 and / or a specific cathode reconnect via 127(c) for each LED.

[0071] In another variant, a single cathode contact reconnect via, common to the LEDs and photosensitive diodes of the device, can be provided at the periphery of the device, with the cathode electrodes of the LEDs and photosensitive diodes then being connected together.

[0072] The process described in relation to the figures 1A à 1I This method can be used to create monolithic micro-displays, combining image display and optical capture functions, for example, to create an interactive screen suitable for implementing face or shape recognition, motion detection, identification, and other functions. One advantage of the described process is that it allows for display and capture pixels with small lateral dimensions, thus achieving high display and capture resolutions. It should be noted that in the example described above, the device comprises macro-pixels, each containing one detection pixel and three emission pixels adapted to emit in three distinct wavelength ranges. In other words, the resolution of the transmitting and receiving devices is identical.Alternatively, the resolution of the display device and the resolution of the optical sensor may differ. In particular, the number of detection pixels may be less than the number of emission pixels for the same wavelength range.

[0073] As an alternative, the process described in relation to the figures 1A à 1I This technology can be used to create larger interactive display devices, such as television, computer, smartphone, or tablet screens. Such a device can comprise a plurality of elementary electronic chips arranged, for example, in a matrix configuration, on a single substrate. The elementary chips are mounted directly onto the substrate and connected to electrical connection elements on the substrate for control. Each chip includes one or more LEDs L1, L2, L3, one or more photosensitive diodes D1, and a control circuit 151 for said LED(s) and photosensitive diode(s). Each chip corresponds, for example, to a macro-pixel of the device.As an example, each chip includes three individually controllable LEDs L1, L2, L3, defining three emission pixels respectively adapted to emit red light, green light and blue light, and a photosensitive diode D1 adapted to detect infrared or near-infrared radiation, defining one detection pixel.

[0074] THE figures 2A à 2G are cross-sectional views illustrating successive stages of an example of a manufacturing process for such a device.

[0075] There figure 2A illustrates in a very schematic way a starting structure which corresponds to a structure of the type obtained by the process of figures 1A à 1I comprising a control integrated circuit stage 151, surmounted by a photodetection stage 201, itself surmounted by an emission stage 203. The photodetection stage 201 comprises a plurality of photosensitive diodes D1 (not detailed in the figures 2A à 2G ) individually controllable by integrated circuit 151. The emission stage comprises a plurality of LEDs L1, L2, L3 (not detailed on the figures 2A à 2G ) individually controllable by integrated circuit 151. On the figure 2A , only the electrical connection pads 153 of the integrated circuit 151, arranged on the side of the upper face of the integrated circuit 151, have been detailed.

[0076] There figure 2B illustrates a step in gluing the structure of the figure 2A on a temporary support substrate 210, for example silicon. The structure of the figure 2A is fixed to the support substrate 210 by its face opposite the control integrated circuit 151, i.e. by its lower face in the orientation of the figure 2B , corresponding to its upper face in the orientation of the figure 2A .

[0077] There figure 2C This illustrates an optional step in thinning the semiconductor substrate of integrated circuit 151, on its side opposite stages 201 and 203. As an example, integrated circuit 151 is initially formed in and on a SOI (Semiconductor On Insulator) substrate. The SOI substrate comprises, for example, a silicon substrate coated with an insulating layer, itself coated with a layer of monocrystalline silicon (not detailed in the figures). The components, particularly transistors, of integrated circuit 151 can be formed in and on the monocrystalline silicon layer of the SOI substrate. The thinning step of the figure 2C may consist of removing the support substrate from the SOI substrate, so as to retain only the single-crystal silicon layer and the insulating layer of the SOI substrate.

[0078] As an alternative, the integrated circuit 151 is formed in and on a solid silicon substrate, the thinning step then consisting of reducing the thickness of the substrate, for example by grinding, from its top face (in the orientation of the figure 2C ). An insulating passivation layer (not detailed in the figure) can then be deposited on the upper face of the thinned substrate.

[0079] There figure 2D illustrates a formation step, on the top side of the integrated circuit 151, of metal connection pads 221, connected to the connection pads 153 and / or to connection terminals of electronic components, for example MOS transistors, of the integrated circuit 151, by means of conductive vias not detailed in the figure, passing through the semiconductor substrate of the integrated circuit 151. Since the pads 221 are essentially connected to connection terminals inside the circuit, their number is in practice greater than the number of pads 153.

[0080] There figure 2E This illustrates a step in forming trenches 230 from the top surface of the integrated circuit 151, vertically traversing the integrated circuit 151, the detection stage 201, and the emission stage 203, and opening onto the top surface of the temporary support substrate 210. The trenches 230 laterally delimit a plurality of semiconductor chips 232 corresponding to the elementary pixel chips of the display device. The trenches 230 can be formed by plasma etching, sawing, or any other suitable cutting method.

[0081] THE figures 2F et 2G illustrate a step of fixing elementary chips 232 onto the upper face of the same transfer substrate 250 of the display device. The transfer substrate 250 comprises, on its upper face, a plurality of metal connection pads 252, intended to be fixed and connected electrically and mechanically to corresponding metal connection pads 221 of the elementary chips 232.

[0082] The structure of the figure 2E is returned ( figure 2F ) so as to place the metal connection pads 221 of elementary chips 232 opposite corresponding metal connection pads 252 of the transfer substrate 250. The opposite pads 221 and 252 are then fixed and electrically connected, for example by direct gluing, by welding, by means of microtubes, or by any other suitable method.

[0083] Once fixed to the transfer substrate 250, the elementary chips 232 are detached from the temporary support substrate 210, and the latter is removed ( figure 2G ). As an example, chip detachment is achieved by mechanical peeling or by peeling using a laser beam.

[0084] In the example shown, the pitch (center-to-center distance in front view) of the elementary chips 232 on the transfer substrate 250 is a multiple of the pitch of the elementary chips 232 on the substrate. Thus, only some of the elementary chips 232 (one out of two in the example shown) are transferred simultaneously from the temporary support substrate 210 to the transfer substrate 250. The other chips remain attached to the temporary support substrate 210 and can be transferred later to another part of the transfer substrate 250 or to another transfer substrate 250.

[0085] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to them. In particular, the embodiments described are not limited to the examples of materials and / or dimensions mentioned in this description.

[0086] Furthermore, in the example described in relation to the figures 1A à 1I The anode regions 113 and the anode metallizations 115 of the photosensitive diodes are produced after the active stack of photosensitive diodes 103 is transferred to the control integrated circuit 151. Alternatively, but not detailed in the figures, the anode regions 113 and the anode metallizations 115 of the photosensitive diodes can be produced before the active stack of photosensitive diodes 103 is transferred to the active stack of LEDs 113. In this case, the layer order of the stack 103 is reversed compared to the example in the figure 1A One advantage is that the activation annealing of the dopants in the 113 regions can then be carried out before transferring the stack 103 onto the integrated circuit 151, which avoids any degradation of the circuit 151 or of the sticking between the stack 103 and the circuit 151 during annealing.

[0087] There figure 3 schematically represents an example of a system comprising an optoelectronic device 300 according to one embodiment.

[0088] The 300 device can be a monolithic micro-screen type device, for example produced by a process of the type described in relation to the figures 1A à 1I .

[0089] As an alternative, device 300 may be a larger device, for example produced by a process of the type described in relation to the figures 2A à 2G .

[0090] The 300 device combines an image display function and an optical capture function, for example to create an interactive screen suitable for implementing face or shape recognition, motion detection, identification, etc.

[0091] The system of the figure 3 It also includes a light source 310. The source 310 is adapted to emit light radiation within the sensitivity range of the photosensitive diodes D1 (not detailed on the figure 3 ) of device 300. As an example, source 310 is an infrared source, for example a laser source.

[0092] In operation, the source 310 illuminates a scene 320 from which an image is to be acquired. The light emitted by the source 310 is reflected by the scene 320 and sent back to the device 300. The photosensitive diodes D1 of the device 300 then allow the acquisition of an image of the scene 320 and / or the measurement of depth information relating to the scene 320.

[0093] In the example of the figure 3 The light source 310 is a remote source, that is to say, it is separate from the device 300. The control of the light source 310 and the control of the detection pixels of the device 300 are, for example, synchronized.

[0094] There figure 4 is a cross-sectional view schematically and partially illustrating another example of an optoelectronic device according to one embodiment.

[0095] In this example, the optoelectronic device incorporates a distributed light source emitting within the sensitivity range of the D1 photodiodes, for example, an infrared source. This eliminates the need for the remote source 310 of the system. figure 3 .

[0096] The device of the figure 4 includes common elements with the device of the figure 1I These elements will not be detailed again below, and only the differences compared to the device of the figure 1I will be highlighted.

[0097] In this example, active layer 143 is a monochromatic emission layer. More specifically, in this example, active layer 143 is a blue light emission layer. However, the embodiments described are not limited to this particular example. A person skilled in the art will be able to adapt the described embodiment in relation to the figure 4 to other emission colors of the active layer 143.

[0098] In the example of the figure 4 Element 165-1 is a photoluminescent conversion element designed to convert the blue light emitted by active layer 143 into red light, and element 165-2 is a photoluminescent conversion element designed to convert the blue light emitted by active layer 143 into green light. In this example, element 165-3 is omitted. Thus, LEDs L1, L2, and L3 define a red light-emitting pixel, a green light-emitting pixel, and a blue light-emitting pixel, respectively.

[0099] In the example of the figure 4 The device further includes a fourth organic LED L4, for example identical or similar to the organic LEDs L1, L2, and L3, which can be individually controlled. LED L4 is surmounted by a photoluminescent conversion element 167, adapted to convert the blue light emitted by the active layer 143 into light radiation with a wavelength within the detection range of the photosensitive diode D1, for example, infrared radiation.

[0100] Thus, LED L4 defines an emissive pixel of a light source adapted to cooperate with photosensitive diodes D1 and replacing source 310 of the system of the figure 3 .

[0101] As described previously, the device of the figure 4 can be a monolithic micro-screen type device, or a pixel of a larger device.

[0102] The number and repetition rate of the organic L4 LEDs can be chosen according to the application requirements. For example, one L4 LED could be used per visible emission pixel, or one L4 LED per photosensitive diode D1, or a different distribution. For instance, the device could include fewer L4 LEDs than visible LEDs L1, L2, or L3. Preferably, the final device (monolithic microdisplay or extended device) includes several L4 LEDs distributed across its surface.

[0103] The conversion elements 165-1, 165-2, and 167, which sit atop LEDs L1 and L2, are made, for example, from quantum dots or perovskite materials. The perovskite-based conversion elements are deposited, for example, by pulsed laser deposition (PLD).

Claims

1. Optoelectronic device manufacturing method, comprising the successive steps of: a) transferring an active inorganic photosensitive diode stack (103) onto an integrated control circuit (151) previously formed inside and on top of a first semiconductor substrate; and b) forming a plurality of organic light-emitting diodes (L1, L2, L3; L4) on the active photosensitive diode stack, wherein, at the end of step a), the active photosensitive diode stack (103) continuously extends over the entire surface of the control circuit (151), the method further comprising, after step a) and before step b), the forming of conductive contacting vias (127(a), 127(b), 127(c), 127(d)) crossing the active photosensitive diode stack (103) and emerging onto metal connection pads (153) of the integration control circuit (151), and wherein, at the end of step b), the organic light-emitting diodes (L1, L2, L3; L4) are connected to the integrated control circuit (151) via said conductive vias, wherein the active photosensitive diode stack (103) is a stack of inorganic semiconductor layers comprising first (103a), second (103b), and third (103c) inorganic semiconductor layers, the second layer (103b) being arranged between the first (103a) and third (103c) layers, and the third layer (103c) being arranged on the side of the integrated control circuit (151) at the end of step a), the method comprising a step of P-type doping of localized portions (113) of the first layer (103a), said portions defining anode regions of photosensitive diodes (D1) of the device.

2. Method according to claim 1, comprising the forming of a plurality of a photosensitive diodes (D1) in the active photosensitive diode stack (103).

3. Method according to claim 1 or 2, wherein, at step a), the active photosensitive diode stack (103) is fixed to the integrated control circuit (151) by direct bonding of a dielectric layer (105) previously deposited on the active photosensitive diode stack (103), with a dielectric layer (155) previously deposited on the integrated control circuit (151).

4. Method according to any of claims 1 to 3, comprising, after step b), the forming of optical filters or of color conversion elements (165-1, 165-2, 165-3) above the organic light-emitting diodes (L1, L2, L3; L4).

5. Method according to claim 4 depending from claim 2, wherein said organic light-emitting diodes (L1, L2, 13, L4) are monochromatic diodes of same color, at least one (L1, L2) of said organic light-emitting diodes being topped with a photoluminescent conversion element (165-1, 165-2) adapted to converting the light emitted by the diode into a visible wavelength and at least another one (L4) of said organic light-emitting diodes (L4) being topped with a photoluminescent conversion element (167) adapted to converting the light emitted by the diode into a light radiation in the wavelength range detected by said photosensitive diodes (D1), preferably an infrared radiation.

6. Method according to claim 5, wherein at least one (L3) of said organic light-emitting diodes is not topped with a photoluminescent conversion element.

7. Method according to claim 4 or 5, wherein said organic light-emitting diodes (L1, L2, L3, L4) are adapted to mainly emitting blue light.

8. Method according to any of claims 5 to 7, wherein said photoluminescent conversion elements (165-1, 165-2, 167) are formed based on quantum dots or on perovskite materials.

9. Method according to any of claims 1 to 8, wherein the active photosensitive diode stack (103) comprises at least one semiconductor layer made of a III-V material.

10. Method according to any of claims 1 to 9, wherein said step of P-type doping of local portions (113) of the first layer (103a) is implemented after step a) and before step b).

11. Method according to claim 10, further comprising, after said step of P-type doping of local portions (113) of the first layer (103a) and before step b), a step of forming of connection metallizations (115) on top of and in contact with said local portions (113) of the first layer (103a).

12. Method according to any of claims 1 to 11, comprising, after step b), a step of bonding of a temporary support substrate (210) onto the side of a surface the device opposite to the integrated circuit (151), followed by a step of cutting of the assembly comprising the integrated circuit (151), the active photosensitive diode stack (103), and the organic light-emitting diodes (L1, L2, L3; L4) into a plurality of elementary chips (232).

13. Method according to claim 12, further comprising a step of transfer and of bonding of said elementary chips (232) onto a transfer substrate (250) of the device, followed by a step of removal of the temporary support substrate (210).

14. Display device comprising a transfer substrate (250) and a plurality of elementary chips (232) bonded and electrically connected to the transfer substrate (250), each elementary chip (232) comprising an optoelectronic device comprising: an integrated control circuit (151) formed in and on a first semiconductor substrate and an active inorganic photosensitive diode stack (103) disposed on the integrated control circuit (151), the active inorganic photosensitive diode stack extending continuously over the entire surface of the integrated control circuit; a plurality of organic light-emitting diodes (L1, L2, L3; L4) arranged on the active photosensitive diode stack; conductive contact vias (127(a), 127(b), 127(c), 127(d)) passing through the active photosensitive diode stack (103) and leading to metal connection pads (153) of the integrated control circuit (151), organic light-emitting diodes (L1, L2, L3; L4) being connected to the integrated control circuit (151) via said conductive vias, wherein the active photosensitive diode stack (103) is a stack of inorganic semiconductor layers comprising first (103a), second (103b) and third (103c) inorganic semiconductor layers, the second layer (103b) being disposed between the first (103a) and third (103c) layers, the third layer (103c) being disposed on the circuit side (151), and the first layer (103a) comprising localized P-type doped portions (113) defining photosensitive diode (D1) anode regions, the integrated control circuit (151) of each elementary chip (232) being arranged on the side of the transfer substrate (250).

15. System comprising a display device (300) according to claim 14, and a light source adapted to emitting a light radiation in the wavelength range detected by said inorganic photosensitive diodes (D1), preferably an infrared radiation.

16. System according to claim 15, wherein the light source is a remote source (310).

17. System according to claim 15, wherein the light source is integrated to the display device (300) and comprises at least one organic light-emitting diode (L4) of an elementary chip (232) of the display device (300).