Method for manufacturing detection circuits

Abstract

The invention relates to a method (100) for manufacturing a plurality of optical-detection circuits (CD), the method comprising the steps of: A providing an initial substrate (SUB) common to the plurality of circuits, B producing alignment holes (HO) on the front face, these holes having what is termed a reference depth (d) of between 5 and 50 µm, C transferring a first intermediate substrate (SH1) onto the front face of the initial substrate (SUB) by bonding, D thinning the rear face of the initial substrate until the bottom of the alignment holes is reached, E collectively performing, for the plurality of sets of pixels, a structuring of the rear face so as to produce a plurality of associated metasurfaces (MS), F transferring a second intermediate substrate (SH2) onto the structured rear face by bonding, G removing the first intermediate substrate.

Description

[0001] TITLE: Manufacturing process for detection circuits

[0002] FIELD OF INVENTION

[0003] The present invention relates to infrared (IR) detectors based on III-V semiconductor materials. More particularly, the invention deals with a method for the collective fabrication of detection circuits integrating microstructures, as well as the fabrication of optical detectors with such detection circuits.

[0004] STATE OF THE ART

[0005] The architecture of a generic IR detector is based on an assembly of a detection circuit comprising an array of elementary pixels, which transforms an incident photon flux into photogenerated carriers, and a readout circuit (commonly called a ROIC for "Read Out Integrated Circuit") to process the electrical signal from the pixels. This assembly is called a hybridization, and the resulting circuit is called a hybrid circuit, which is an optical detector.

[0006] A detection circuit consists of a pixel array, where each pixel corresponds to an IR photodetector, converting IR radiation into an electrical signal. The spectral ranges addressed by detection circuits are the near-infrared (NIR), mid-infrared (MWIR), and far-infrared (LWIR). The pixels in the detection circuit typically comprise a stack of different layers, including an active layer to convert detected photons into charge carriers and contact layers to transfer the electrical signal from the pixel to the readout circuit.

[0007] It is known in the prior art to fabricate microstructures on the so-called back face of the detection circuit—that is, on the substrate face opposite the pixels and which receives the incident optical wave—forming a metasurface that acts on the incident optical wave before it reaches the pixel. A set of microstructures is associated with a pixel; this set's function is, for example, to deflect, focus, or polarize the radiation incident on the pixel.

[0008] A metallens performs a lensing function and comprises all the microstructures associated with each pixel. This metallens increases the light collection efficiency for each pixel by focusing the radiation through the substrate. The microstructures can be of different types, employing different physical phenomena.

[0009] As a first example, we can cite microstructures that create an effective refractive index, enabling the realization of optical functions, for example, microlenses as described in the publication by Zhang et al., "Solid-Immersion Metalens for Infrared Focal Plane Arrays" (arXiv / physics). In this case, the microstructures have a sub-wavelength dimension, that is, a dimension smaller than the so-called operating wavelength corresponding to that detected by the active layer of the pixel. For a sensitivity within a given spectral range, the microstructures have a dimension smaller than the lower bound of the spectral band.

[0010] A second example is the resonator-type microstructures (nano-antennas) forming a Huygens metasurface, as described in documents EP3662511 and US11171168 for focusing applications in an IR detector. In this case, the microstructures form resonators, with a size on the order of the wavelength, typically plasmonic antennas, which re-emit (radiate), from an incident wave, light with a resonance wavelength, by modifying the phase of the incident wave.

[0011] The microstructures can be made directly in the substrate of the detection circuit, or in an additional layer (dielectric, metallic) deposited on the substrate.

[0012] The design parameters of the metasurface depend on the desired function, the type of microstructure, and the targeted spectral detection band.

[0013] However, the fabrication of this type of structure presents numerous challenges. A primary difficulty lies in the creation of the metasurfaces themselves. For example, some of these microstructures exhibit a high aspect ratio, such as those composed of III-V semiconductor pillars etched to a depth of a few microns. Their fabrication requires a specific process using an electron beam lithography step and dry etching, which must be perfectly controlled to guarantee the desired effect on the incident signal. Constraints on maintaining the dimensions of the microstructures are significant to ensure their optical properties. A second difficulty concerns the alignment of these microstructure assemblies with their respective pixels. A strategy for aligning the patterns on the back side of the various detection circuits present on the substrate must be implemented to guarantee an alignment of less than one micron.

[0014] A third difficulty arises in the manufacturing sequence. In a standard process for manufacturing detection circuits, the metasurface would be fabricated after hybridization onto the readout circuit. However, this method would encounter potential technological incompatibilities (thermal budget, handling, risk of circuit damage from electrostatic discharge, etc.). Another difficulty stems from the collective fabrication of metasurfaces. It is impossible and inconceivable to fabricate these metasurfaces once the detection circuit has been transferred to the readout circuit. Indeed, handling the hybridized components is difficult, and integrating these objects into electron beam lithography and dry etching processes is incompatible, risking damage to the component.

[0015] Even if this were possible, the creation of metasurfaces on each hybridized component would be very long and costly to implement, and ultimately incompatible with high-yield industrial production.

[0016] One objective of the present invention is to overcome the aforementioned drawbacks by providing a method for manufacturing detection circuits that collectively integrate metasurfaces on their rear faces, prior to assembly with their readout circuit. Furthermore, the method for fabricating the detection circuits according to the invention can be incorporated into a manufacturing process for a complete hybrid component.

[0017] DESCRIPTION OF THE INVENTION

[0018] The present invention relates to a method for manufacturing a plurality of optical detection circuits, said optical detection circuits being intended to be assembled with reading circuits to form optical detectors, and being configured to detect an incident optical wave comprising a wavelength referred to as the operating wavelength, the method comprising the steps of:

[0019] To have a common initial substrate for said plurality of circuits, made of III-V semiconductor material, having a front face on which is arranged a plurality of pixel sets and a rear face, a pixel being configured to convert a detected optical wave into an electrical signal,

[0020] B. to drill alignment holes on said front face with a so-called reference depth between 5 and 50 pm,

[0021] C. Transfer to the said front face of the initial substrate a first intermediate substrate by gluing.

[0022] To thin the rear face of the initial substrate until reaching the bottom of said alignment holes, said initial substrate then having a thickness equal to said reference depth and being called the thinned substrate,

[0023] To collectively realize, for the plurality of sets of pixels, a structuring of the back face so as to realize a plurality of associated metasurfaces, a metasurface comprising microstructures having a dimension less than or equal to said wavelength of use (X0), a set of microstructures being associated with a pixel, arranged with respect to said pixel in a predetermined manner and configured to modify the optical wave incident on said associated pixel,

[0024] F. Transfer to the structured rear face a second intermediate substrate by gluing.

[0025] G remove the first intermediate substrate,

[0026] each set of pixels from the plurality of pixel sets, arranged on a fraction of the thinned substrate and having a back face on which an associated metasurface is made, forming an optical detection circuit.

[0027] According to one embodiment, steps C and F of the bonding are carried out with a photosensitive polymer.

[0028] According to one embodiment, the bonding of the first intermediate substrate in step C is carried out with a first polymer sensitive in a first spectral band, and the bonding of the second intermediate substrate in step F is carried out with a second polymer sensitive in a second spectral band different from the first spectral band.

[0029] According to one embodiment, step G of the removal of the first intermediate substrate is carried out by detachment with a first laser beam having a first wavelength included in the first spectral band and not included in the second spectral band, the first intermediate substrate being transparent to said first wavelength

[0030] According to one embodiment, the first and / or second intermediate substrate are made of glass or silicon.

[0031] According to another aspect, the invention relates to a first variant of a method for making an optical detector comprising the steps of:

[0032] H1 to have a plurality of optical detection circuits arranged on the second intermediate substrate as obtained at the end of step G of the process according to one aspect of the invention,

[0033] 11. Separate the said optical detection circuits bonded to said second intermediate substrate from each other,

[0034] J1 for an optical detection circuit, treat a surface of the pixels of said optical detection circuit in preparation for assembly,

[0035] K1 assemble by hybridization said optical detection circuit bonded to said second intermediate substrate with a reading circuit,

[0036] L1 remove the second intermediate substrate, an optical detection circuit assembled with a readout circuit forming an optical detector.

[0037] According to another aspect, the invention relates to a second variant of a method for making an optical detector comprising the steps of:

[0038] H2 has a plurality of optical detection circuits arranged on the second intermediate substrate as obtained at the end of step G of the process according to one aspect of the invention,

[0039] 12. To collectively process a surface of pixels from a plurality of optical detection circuits, in preparation for assembly,

[0040] J2 assemble by hybridization said plurality of optical circuits with a plurality of associated reading circuits implemented on a common substrate,

[0041] K2 remove the second intermediate substrate, L2 separate from each other the said optical detection circuits assembled with the said associated reading circuits, an optical detection circuit assembled with a reading circuit forming an optical detector.

[0042] According to one embodiment of an optical detector, the bonding of the second intermediate substrate was implemented with a second polymer sensitive in a second spectral band, and the L1 or K2 step of removal of the second intermediate substrate is carried out by peeling with a second laser beam having a second wavelength included in the second spectral band and not included in the first spectral band, the second intermediate substrate being transparent to said second wavelength.

[0043] According to one embodiment, in step F the second polymer was positioned in localized areas outside the metasurfaces, and the second laser beam operating the take-off in step L1 or in step K2 is oriented so as to illuminate said areas.

[0044] The following description presents several embodiments of the device of the invention; these examples are not intended to limit the scope of the invention. These embodiments illustrate both the essential features of the invention and additional features related to the embodiments considered. The invention will be better understood, and other features, purposes, and advantages thereof will become apparent in the detailed description that follows and with reference to the accompanying drawings, which are given by way of non-limiting examples and in which:

[0045] Figure 1 illustrates the different stages of the manufacturing process for a plurality of circuits according to the invention.

[0046] Figure 2 illustrates the technological steps A to D according to the invention.

[0047] Figure 3 illustrates the initial substrate after step B according to the invention.

[0048] Figure 4 illustrates the technological steps E to G according to the invention.

[0049] Figure 5 illustrates the diagram of the different steps H1 to L1 of a first variant of a method for making a detection circuit according to the invention.

[0050] Figure 6 schematically illustrates the technological steps H1 to L1. Figure 7 illustrates the diagram of the different steps H2 to L2 of a second variant of the method for making a detection circuit according to the invention.

[0051] Figure 8 schematically illustrates the technological stages H2 to L2.

[0052] DETAILED DESCRIPTION OF THE INVENTION

[0053] The invention relates to a method 100 for manufacturing a plurality of optical detection circuits (CDs). The method is collective, meaning that the CDs of the plurality are manufactured simultaneously. The optical detection circuits (CDs) are intended to be assembled with readout circuits (CLs) to form optical detectors (DOs), also called hybrid circuits (CHs). The detection circuits (CDs) are configured to detect an incident optical wave (OIB) comprising a wavelength ΔO, referred to as the operating wavelength. An optical detection circuit is configured to detect the operating wavelength, that is, to transform the optical wave at ΔO, or in a spectral band around ΔO, into an electrical signal.

[0054] The different steps A to G of process 100 according to the invention are listed in figure 1 and the technological steps are illustrated in figure 2 (steps A to D) and figure 4 (steps E to G).

[0055] The first step, A, consists of a common substrate, SUB, called the initial substrate, made of Mat 111-V semiconductor material, as illustrated in Figure 3. The SUB substrate has a front face, called FAV, on which a plurality of pixel sets, Ens, are arranged. A pixel is configured to convert the detected incident optical wave into an electrical signal. Typically, the pixels in a set, Ens, are arranged in a matrix. The SUB substrate also includes a back face, FAR.

[0056] In step B, alignment holes HO are created on the face, also illustrated in Figure 3. The holes have a reference depth d between 5 and 50 µm, and are preferably square, with a width between 5 and 50 µm. In one embodiment, the holes are arranged around the periphery of the pixel sets. This allows for a greater number of alignment elements, which will be used to achieve the final alignment, without hindering the manufacturing process.

[0057] Figure 3 illustrates an example of an initial SUB substrate with four matrix Ens sets of pixels, one matrix set being used to form a CD detection circuit, with the HO holes at the periphery of the Ens sets. Preferably, the holes are created by dry etching. The advantage of dry etching is that it preserves dimensional anisotropy. Thus, deep patterns can be created without spreading horizontally.

[0058] As explained later, the holes will allow us to define the final thickness of the CD detection circuit after thinning (see step D). The holes will also serve as alignment marks for the future lithography of the metasurfaces (see step E). Indeed, it is essential to perfectly align the metasurfaces etched on the back side with the Pix pixels arranged on the front side.

[0059] In step C, a first intermediate substrate SH1 is (temporarily) attached to the front face of the SUB substrate by bonding with a first adhesive, referenced GL1. The intermediate substrate SH1 mechanically stabilizes the complete vertical structure during the thinning of the back face of the III-V substrate (see step D). Its presence allows for safe handling of the III-V SUB substrate without risk of breakage. Excessive mechanical deformation of the III-V SUB substrate after thinning is avoided, as this could compromise its flatness and, consequently, the quality of the metasurface lithography (Step E).

[0060] In step D, the rear face FAR of the SUB substrate is thinned until it reaches the bottom of the holes HO. The substrate then has a thickness determined by the holes HO and equal to the reference depth d. Once thinned, the substrate, designated SUBa in Figures 2 and 4, typically has a thickness d between 5 and 50 µm.

[0061] The thinning process, for example, is of a mechano-chemical type.

[0062] In step E, the back surface is collectively structured for the plurality of pixel sets Ens to create a plurality of associated metasurfaces MS. An MS metasurface comprises microstructures MST with a dimension less than or equal to the operating wavelength X0. Each pixel Pix is ​​associated with a set of microstructures, arranged relative to the pixel in a predetermined manner and configured to modify the optical wave incident on the pixel Pix. For example, a set of microstructures facing the associated pixel is configured to create a microlens with a predetermined focal length, typically equal to the thickness d of the thinned substrate, so as to focus the incident light from the back surface FAR onto the detection pixels after passing through the thinned substrate SLIBa.

[0063] The metasurface can be based on microstructures with an effective refractive index or Huygens microstructures, as described above, or any other type of microstructure that allows modification of the path or polarization of the incident wave. Metasurfaces are typically fabricated using lithography and dry etching. Dry etching is anisotropic, unlike wet etching, which is isotropic. The dimensions of the microstructures are therefore preserved during the transfer process.

[0064] A perfect alignment of the metasurfaces with the corresponding pixels on the front face is achieved using the predefined holes before step C of bonding with the first host substrate SH1.

[0065] In a step F, a second intermediate substrate SH2 is transferred onto the structured back face (metasurface side) by gluing, with a second glue referenced GL2.

[0066] According to one embodiment, the intermediate substrates SH1 and / or SH2 are made of glass or silicon.

[0067] In step G, the first intermediate substrate SH1 is removed.

[0068] Each set of pixels Ens from the plurality of pixel sets is arranged on a fraction of the thinned substrate and has a back face on which an associated metasurface is fabricated. The assembly comprising the matrix Ens of pixels Pix arranged on a fraction of the thinned substrate, the back face of which is structured with an associated metasurface, forms an optical detection circuit CD. At the end of step G, a structure 30 is thus obtained comprising a plurality of optical detection circuits CD, the structured face of each of the substrates of the CD circuits being bonded to the same substrate, the second intermediate substrate SH2. In summary, the process 100 according to the invention is based on two steps of temporary bonding of the substrate SUB on which the detection circuits have been fabricated.Initially, the front face of the SUB III-V substrate, containing the pixels of several detection circuits, is temporarily bonded to a host substrate SH1. The exposed face of the SUB III-V substrate is then thinned to the desired thickness. The fabrication of the metasurfaces becomes possible. To remove the first host substrate SH1, a new temporary support SH2 is placed on the metasurface side.

[0069] The final detectors are not yet individualized (the readout circuit is missing). This structure 30 can be transported from one production line to another, possibly located in a different place, or even in a different factory. An advantage of the process 100 according to the invention is the collective fabrication of metasurfaces on the back side of the flat substrate of the detection circuits, before transfer to their readout circuit. This fabrication is carried out by ensuring the perfect positioning of the metasurface patterns by self-alignment, thus differentiating it from other lithography approaches that conventionally use alignment marks. All conventional microelectronic manufacturing technologies can be used in terms of lithography or plasma dry etching. The III-V SUB material and its SH1 / SH2 host substrates are compatible with all standard equipment.

[0070] The process according to the invention also offers a handling advantage, as the SUB substrate is thinned to achieve the desired thickness on its back side. The temporary bonding also allows for safe handling of the III-V (SUB) wafer, ensuring a flat back side that facilitates the fabrication of metasurfaces.

[0071] The process according to the invention overcomes the technological barrier that previously required manufacturing each metasurface on the finalized and individualized optical detector, i.e., already assembled to the reading circuit. This individual manufacturing is indeed very difficult in terms of handling and is not compatible with existing equipment, resulting in prohibitively high production yields.

[0072] The fabrication of the metasurfaces is integrated into the manufacturing process of the detection circuits on a common substrate. The optical detection circuits are located on the common SUB wafer, which can receive the metasurface fabrication on its back side via a planar collective process.

[0073] Furthermore, the flatness of the SUB substrate and the precise alignment of the metasurfaces with the Pix pixels on the front panel allow for high manufacturing yields. In addition, process 100 allows for simpler handling of the III-V SUB substrate on which the detection circuits and metasurfaces are fabricated, particularly during the thinning step D.

[0074] Thus, the 100 process is based on two key points:

[0075] The temporary double bonding of the III-V SUB substrate, containing the detection circuits, thus enabling the realization of metasurfaces, using host substrates in glass or silicon.

[0076] The perfect alignment of the metasurfaces with the pixels manufactured on the front face using the predefined holes before gluing.

[0077] Detector finalization can be carried out in two ways, depending on how the optical and electronic components are combined with the readout circuit. Hybridization refers to the assembly of the optical and electronic parts of a detector without affecting its optical / electronic performance. The resulting detector is commonly called a hybrid circuit. Hybridization is typically performed using a "flip chip" method. Flip chip hybridization of the optical part onto the electronic part (ROIC) is achieved using indium microbeads pre-deposited onto the ROIC. Through a thermal cycle, these microbeads are fused, resulting in the interconnection of the two components.

[0078] Thus, according to another aspect, the invention relates to a method for making an optical detector, from the structure obtained with method 100 according to the invention.

[0079] Method 200 for fabricating a DO optical detector corresponds to the first variant, known as individual hybridization. Figure 5 illustrates the diagram of the different steps H1 to L1, and Figure 6 schematically illustrates the technological steps H1 to L1. Method 200 uses the second intermediate substrate SH2 on which the plurality of optical detection circuits is arranged (via bonding), as obtained by method 100.

[0080] Process 200 includes a step H1 consisting of arranging a plurality of optical detection circuits CD on the second intermediate substrate SH2 as obtained at the end of step G of process 100. In a subsequent step 11, the optical detection circuits bonded to the second intermediate substrate SH2 are separated from one another, typically by cutting. The optical detection circuits CD are now individualized. The following operations are therefore performed on each circuit CD independently of the others. For a given circuit CD, in a step J1, the surface of the pixels of the circuit CD is treated in preparation for assembly.

[0081] In step K1, the optical detection circuit CD, bonded to the second intermediate substrate SH2, is assembled by hybridization with a readout circuit CL (also separate). Finally, in step L1, the second intermediate substrate SH2 is removed. The optical detection circuit CD, assembled with a readout circuit CL, forms an optical detector DO.

[0082] The advantage of this individual hybridization is that it leads to more precise control of the alignment of the optical detection circuit CD with the reading circuit CL. This approach allows for the correction of misalignment.

[0083] Method 300 for fabricating a DO optical detector corresponds to the second variant, known as collective hybridization. Figure 7 illustrates the diagram of the different steps H2 to L2, and Figure 8 schematically illustrates the corresponding technological steps. Method 300 uses the second intermediate substrate SH2 on which the plurality of optical detection circuits is arranged (via bonding), as obtained by method 100.

[0084] The process 300 includes a step H2 consisting of arranging a plurality of optical detection circuits CD on the second intermediate substrate SH2 as obtained at the end of step G of the process 100.

[0085] In step I2, the surface of the pixels of the plurality of optical detection circuits is collectively processed in preparation for assembly. The processing is of the same type as that described for step J1.

[0086] In step J2, the plurality of optical circuits DO is assembled by hybridization with a plurality of associated readout circuits CL implemented on a common substrate SUBcl. This hybridization is thus performed on all the DO circuits simultaneously since they are still connected to each other via the substrate SH2.

[0087] In step K2, the second intermediate substrate SH2 is removed. Finally, in step L2, the optical detection circuits assembled with their associated readout circuits are separated, typically by cutting. This yields several optical detectors DO in parallel, each formed by assembling an optical detection circuit CD with a readout circuit CL.

[0088] The advantage of collective hybridization is a saving of time and a reduction in cost due to a single reporting step.

[0089] Processes 200 and 300 thus enable the collective fabrication of optical detectors with metasurfaces. Process 200 only fabricates the metasurfaces collectively, while hybridization is performed individually. Process 300 fabricates both the metasurfaces and the hybridization collectively.

[0090] The temporary bonding steps C and F, also known as "bonding," and the debonding steps, also known as "debonding," can be carried out according to different physical principles combining a bonding material and an associated physical debonding effect. Debonding can be achieved using light (e.g., a laser), heat, or mechanically.

[0091] In addition, according to one embodiment, the temporary bonding can be specifically localized on the sample.

[0092] According to a variant of the manufacturing process for a plurality of optical detection circuits, the temporary bonding steps C and F are implemented with a photosensitive polymer.

[0093] In the process according to the invention there are two steps of bonding two host substrates SH1 and SH2 and it must be possible to selectively detach one host substrate at a given time without detaching the other host substrate.

[0094] To this end, according to one embodiment, the bonding of the first intermediate substrate SH1 in step C is carried out with a first polymer PPS1 sensitive in a first spectral band AX1, and the bonding of the second intermediate substrate SH2 in step F is carried out with a second polymer PPS2 sensitive in a second spectral band AX2 different from AX1. It is important that AX2 does not completely overlap AX1: the two spectral bands AX1 and AX2 must each have a portion not included in the other spectral band.

[0095] In this way, according to one embodiment of process 100, step G, the removal of the first intermediate substrate SH1, is carried out by peeling with a first laser beam FL1 having a first wavelength within the first spectral band AX1 and not within the second spectral band AX2. For this to work, the first intermediate substrate SH1 must be transparent to the first wavelength X1. Indeed, the illumination of PPS1 for peeling is carried out through SH1. Since the polymer PPS2 is not sensitive to X1, the second intermediate substrate SH2 is not peeled.

[0096] According to an embodiment of processes 200 and 300 of the invention, the respective steps L1 or K2 of removing the second intermediate substrate SH2 are carried out by debonding with a second laser beam FL2 having a second wavelength Φ2 within the second spectral band AX2 and not within AX1. The second intermediate substrate SH2 is transparent to the second wavelength Φ2 because the debonding is performed with FL2 through SH2. Thanks to the differences in the spectral sensitivity range of the two polymers used and a judicious choice of X1 and X2, the debonding can be carried out selectively. Furthermore, laser debonding has the advantage of not causing a temperature rise that could be detrimental to the circuits.

[0097] An example of the implementation of "bonding / debonding" with a photosensitive polymer detached by laser is proposed by the company EVG.

[0098] When the SH1 and SH2 substrates are detached, the surfaces must be thoroughly cleaned (pixel side for SH1 and metasurface side for SH2) to remove any residual polymer. A challenge arises on the metasurface side, with small microstructures where residual polymer can be difficult to remove.

[0099] According to one embodiment, made possible by the polymer / laser combination, the polymer can be selectively positioned outside the area in which the microstructures (metasurfaces) are etched. The laser enables selective delamination by illuminating only the areas where the polymer is located: the second polymer, PPS2, is positioned in areas located outside the MS metasurfaces, and the second laser beam performing the delamination in step L1 or step K2 is directed to illuminate these areas. This avoids filling the areas between the microstructures. The industrial application targeted by processes 100, 200, and 300 according to the invention is the collective fabrication of hybrid circuits with metasurfaces on the back side.In general, these manufacturing processes apply to all types of detection circuits integrated into their readout circuit, with optical, micron, or submicron functionalization of their collector (illuminated) face. These manufacturing methods fit directly into an existing, conventional process for fabricating hybrid circuits without metasurfaces.

Claims

DEMANDS 1. A method (100) for manufacturing a plurality of optical detection circuits (OCs), said optical detection circuits being intended to be assembled with readout circuits (LCs) to form optical detectors, and being configured to detect an incident optical wave comprising a wavelength (X0) referred to as the operating wavelength, the method comprising the steps of: To have an initial substrate (SUB) common to said plurality of circuits, made of 11V semiconductor material (Mat), having a front face (FAV) on which is arranged a plurality of sets (Ens) of pixels (Pix) and a back face (FAR), a pixel being configured to convert a detected optical wave into an electrical signal, B. to make alignment holes (HO) on said front face having a depth (d) called reference depth between 5 and 50 pm, C transfers a first intermediate substrate (SH1) onto the front face of the initial substrate (SUB) by gluing, To thin the rear face of the initial substrate until reaching the bottom of said alignment holes, said initial substrate then having a thickness equal to said reference depth and being called the thinned substrate, To collectively realize, for the plurality of pixel sets, a structuring of the back face so as to realize a plurality of associated metasurfaces (MS), a metasurface comprising microstructures having a dimension less than or equal to said operating wavelength (X0), a set of microstructures being associated with a pixel, arranged with respect to said pixel in a predetermined manner and configured to modify the optical wave incident on said associated pixel, F. Transfer a second intermediate substrate (SH2) onto the structured rear face by bonding. G remove the first intermediate substrate, each set of pixels of the plurality of sets of pixels, arranged on a fraction of the thinned substrate and having a back face on which is made an associated metasurface, forming an optical detection circuit (CD).

2. A method (100) for manufacturing a plurality of optical detection circuits (CDs) according to claim 1, wherein the bonding steps C and F are carried out with a photosensitive polymer.

3. A method (100) for manufacturing a plurality of optical detection circuits (CDs) according to the preceding claim, wherein the bonding of the first intermediate substrate (SH1) in step C is carried out with a first polymer sensitive in a first spectral band (AX1), and the bonding of the second intermediate substrate (SH2) in step F is carried out with a second polymer sensitive in a second spectral band (AX2) different from the first spectral band.

4. Method (100) of manufacturing a plurality of optical detection circuits (CD) according to the preceding claim wherein the step G of removing the first intermediate substrate (SH1) is carried out by peeling with a first laser beam having a first wavelength (X1) included in the first spectral band and not included in the second spectral band, the first intermediate substrate (SH1) being transparent to said first wavelength (X1).

5. Method (100) of manufacturing a plurality of optical detection circuits (CD) according to any one of the preceding claims wherein the first and / or second intermediate substrate are made of glass or silicon.

6. Method (200) for making an optical detector (OD) comprising the steps of: H1 to have a plurality of optical detection circuits (CDs) arranged on the second intermediate substrate as obtained at the end of step G of the process according to any one of claims 1 to 5, 11. Separate the said optical detection circuits bonded to said second intermediate substrate from each other, J1 for an optical detection circuit, treat a surface of the pixels of said optical detection circuit in preparation for assembly, K1 assemble by hybridization said optical detection circuit (CD) bonded to said second intermediate substrate with a reading circuit (CL), L1 remove the second intermediate substrate, an optical detection circuit (CD) assembled with a readout circuit (CL) forming an optical detector (DO).18 7. Method (300) for making an optical detector (OD) comprising the steps of: H2 has a plurality of optical detection circuits arranged on the second intermediate substrate as obtained at the end of step G of the process according to any one of claims 1 to 5, I2 collectively process a surface of pixels from the plurality of optical detection circuits, in preparation for an assembly, J2 assemble by hybridization said plurality of optical circuits with a plurality of associated readout circuits (LC) implemented on a common substrate, K2 remove the second intermediate substrate, L2 separate from each other the said optical detection circuits assembled with the said associated reading circuits, an optical detection circuit (CD) assembled with a reading circuit (CL) forming an optical detector (DO).

8. Method (200, 300) of making an optical detector (OD) according to any one of claims 6 or 7 wherein the bonding of the second intermediate substrate (SH2) has been carried out with a second polymer sensitive in a second spectral band (AX2), and wherein the step L1 or the step K2 of removal of the second intermediate substrate (SH2) is carried out by peeling with a second laser beam having a second wavelength (X2) included in the second spectral band and not included in the first spectral band, the second intermediate substrate (SH2) being transparent to said second wavelength (X2).

9. Method (200, 300) of making an optical detector (OD) according to the preceding claim wherein in step F the second polymer has been positioned in localized areas outside the metasurfaces, and wherein the second laser beam operating the take-off in step L1 or in step K2 is oriented so as to illuminate said areas.

Images