Photodetector, Modulator, Semiconductor Device, and Semiconductor Device

Abstract

The present invention relates to a photodetector 3, comprising a longitudinal cross section 12 of a waveguide 11, which includes or is formed by at least two longitudinally extending waveguide segments 12a, 12b that are substantially parallel to one another, and an active element 13 that overlaps the longitudinal cross section 12 of the waveguide 11 and includes or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical optical signal as a result of said absorption. The waveguide segments 12a, 12b are preferably laterally spaced apart from one another so as to form a gap 14 extending between them. The two waveguide segments 12a, 12b are each at least partially in contact on at least one side, in particular the side facing the active element 13, with a gate electrode 15a, 15b, preferably including or consisting of silicon.

Description

Technical Field

[0001] The present invention relates to photodetectors and modulators. Further, the present invention relates to a chip and a semiconductor device having at least one photodetector and / or modulator, and to a wafer and a semiconductor device having at least one photodetector and / or modulator.

Background Art

[0002] Electro-optic elements, such as photodetectors or modulators (electro-optic modulators), are known from the prior art. The electro-optic element includes a waveguide having several waveguide segments extending in the longitudinal direction and at least substantially parallel to each other, or a longitudinal cross-section thereof. In the case of a photodetector, it includes one graphene film as an active element, and in the case of a modulator, it includes two graphene films as active elements. Such are disclosed, for example, in U.S. Patent No. 9,893,219.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Known photodetectors and modulators have proven their own principles. However, there is a desire for further, alternatively designed photodetectors and modulators that can be manufactured with reasonable effort and are characterized by an optimal operating mode.

[0004] Therefore, an object of the present invention is to provide alternatively designed photodetectors and modulators that meet these requirements.

[0005] This object is solved for the photodetector by the means according to claims 1 and 6, and for the modulator by the means according to claims 9, 10 and 11.

[0006] According to a first aspect of the present invention, a photodetector comprises or is formed by a longitudinal cross-section of a waveguide including or formed by at least two longitudinally extending waveguide segments that are substantially parallel to each other, and an active element including or consisting of at least one material that overlaps the longitudinal cross-section of the waveguide, absorbs electromagnetic radiation of at least one wavelength, and generates an electro-optical signal as a result of the absorption. The two waveguide segments are preferably laterally spaced apart from each other so as to form a gap extending therebetween, and each of the two waveguide segments is in contact with a gate electrode that at least partially, preferably includes or consists of silicon, particularly on at least one side, in particular on the side facing the active element.

[0007] A method of manufacturing such a photodetector of the present invention includes, for example, a step of producing by preferably depositing a waveguide material on a coating provided in contact or non-contact, particularly on a wafer, a step of producing by particularly depositing a gate electrode material, preferably silicon, a step of performing structuring to obtain two waveguide segments having a gap and a gate electrode, and a step of providing an active element.

[0008] A pn junction can be realized in the active element during operation by the gate electrode. By arranging the pn junction in the optical mode region, an optimal overlap between the absorption material and the active region of the photodetector is achieved.

[0009] In an advantageous embodiment, each of the gate electrodes is in contact with the upper surface of the waveguide segment on its lower side and with the lower surface of a dielectric coating provided between the active element and the waveguide segment on its upper side. The dielectric coating comprises or is composed of at least one dielectric material. Suitable dielectric materials are, for example, silicon dioxide (SiO 2 ) and aluminum oxide (Al 2 O 3) has been proven. Instead of the term "dielectric material", the term "dielectric" is also used. The dielectric film can also be called a gate dielectric.

[0010] The active element may be disposed earlier or later on the upper side of the dielectric film, and it may be manufactured earlier or later on its upper side.

[0011] In a preferred embodiment, the dielectric coat can be characterized by a roughness in the range of 1.0 nm RMS to 0.1 nm RMS, particularly 0.6 nm RMS to 0.1 nm RMS, preferably 0.4 nm RMS to 0.1 nm RMS on its upper side. RMS represents the root mean square. It has been proven that the upper surface having a roughness in this range is particularly suitable when the active element is provided on the upper side of the dielectric film, particularly in the form of deposition.

[0012] The thickness of the dielectric coat may be, for example, in the range of 10 to 20 nm.

[0013] Preferably, the gate electrode comprises or is composed of a material that is transparent to electromagnetic radiation of at least one wavelength, preferably at least one wavelength range, and / or is conductive.

[0014] More preferably, the gate electrode comprises or consists of at least one material that is transparent to electromagnetic radiation having a wavelength of 850 nm and / or 1310 nm and / or 1550 nm. In particular, it is preferably transparent to electromagnetic radiation in the wavelength ranges of 800 nm to 900 nm and / or 1260 nm to 1360 nm (so-called original band or abbreviated as O band) and / or 1360 nm to 1460 nm (so-called extended band or abbreviated as E band) and / or 1460 nm to 1530 nm (so-called short band or abbreviated as S band) and / or 1530 nm to 1565 nm (so-called conventional band or abbreviated as C band) and / or 1565 nm to 1625 nm (so-called long band or abbreviated as L band). These bands are known in the field of telecommunications engineering.

[0015] Such materials are preferentially applied to the gate electrode materials used in the manufacturing method.

[0016] Silicon has been proven to be a particularly suitable material for the gate electrode. Polysilicon can also be used. Indium tin oxide (ITO) may also be considered. The material constituting the gate electrode can also be doped.

[0017] Each gate electrode is preferably, for example, a coating provided on each waveguide segment of the longitudinal cross-section of the waveguide facing the active element, in particular a coating fabricated or fabricated on each waveguide segment.

[0018] Furthermore, the gate electrode is created either previously or later, in particular by depositing a coating material by chemical vapor deposition (CVD), preferably low-pressure chemical vapor deposition (LPCVD) and / or plasma-enhanced chemical vapor deposition (PECVD) and / or physical vapor deposition (PVD).

[0019] There are various prior art chemical vapor deposition processes, and all of these processes can be used in the context of the present invention. What is common to all of these is usually a chemical reaction of the introduced gas, which results in the deposition of the desired material.

[0020] Also, with respect to physical vapor deposition, all types known in the prior art may be used. By way of pure example, electron beam evaporation in which a material is melted and evaporated using an electron beam, thermal evaporation in which a material is heated to its melting point and evaporated onto a target substrate, and sputter evaporation in which atoms are knocked out from a material carrier using a plasma and deposited onto a target substrate can be mentioned.

[0021] Alternatively, or in addition to the above deposition processes, atomic layer deposition (ALD) can be used to obtain the gate electrodes. In this method, an insulating material or a conductive material (dielectric, semiconductor or metal) is continuously deposited by atomic layers. Also, a transfer process can be used.

[0022] Furthermore, each of the two gate electrodes is associated with a connection element in contact with them, and one of the connection elements can extend through one of the waveguide segments. After deposition, appropriate structuring processes such as, for example, lithography and / or etching may be performed. The connection element is preferably a vertical interconnect access (Vertical Interconnect Access), abbreviated as VIA. VIAs are usually defined by lithography and etched by dry chemical etching, particularly reactive ion etching (abbreviated as RIE). Thereafter, it is preferably metallized, and the metallized surface is structured by CMP (Damascene process) or lithography and RIE.

[0023] Reactive ion etching is a dry etching process, according to which selective and directional etching of the substrate surface is usually achieved by a special gaseous chemical substance excited to form a plasma. A resist mask can be used to protect the parts that are not to be etched. The etching chemistry and process parameters usually determine the selectivity of the process, i.e., the etching rates of different materials. This property is important for limiting the etching process in depth and for defining the coatings separately from each other.

[0024] For the sake of convenience, the connecting element comprises or consists of at least one electrically conductive material, in particular a metal such as copper and / or aluminum and / or tungsten.

[0025] In another advantageous embodiment, furthermore, the active element is provided to at least partially, in particular laterally, overlap the two waveguide segments and the gap located at least in part therebetween. The lateral direction should be understood, for the sake of convenience, as the direction orthogonal to the longitudinal direction of the cross-section of the waveguide.

[0026] According to a second aspect of the invention, there is provided an optical detector comprising a longitudinal cross-section (12) of a waveguide (11) and an active element comprising or consisting of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electro-optical signal as a result of the absorption, On both sides of the longitudinal cross-section of the waveguide, so as to form two gaps, two Support elements are spaced apart, the two gaps are free of material, and the active element overlaps at least a part of the longitudinal cross-section of the waveguide, the two gaps and the two Support elements. to O Preferably, the two Support elements are laterally spaced from the longitudinal cross-section.

[0027] The method according to the present invention for manufacturing such a photodetector comprises, for example, the step of preferably depositing a waveguide material on a wafer or on a film provided on the wafer, and two gaps as well as the waveguide and Support the step of structuring to obtain a longitudinal cross-section of the element, and the waveguide and Support the step of providing an active element on the upper side of the longitudinal cross-section of the element.

[0028] The gaps that do not contain material are provided, in particular, by regions where the material is removed by an etching process and then not provided by depositing new material, for example. They can be filled with air or other gases, or can be made into a vacuum. However, there is no solid substance in them. The vacuum should preferably be understood as a vacuum space obtained, for example, by pumping.

[0029] In a preferred embodiment, the active element is located on the upper side of the longitudinal cross-section of the waveguide facing the active element and / or on the upper side of the Support element facing the active element.

[0030] Support The element may be of the same material as the longitudinal cross-section of the waveguide, which is to be understood as exemplary. For example, TiO2 and / or Si have Support been proven to be materials suitable for the element. Any other material suitable for the waveguide can also be considered.

[0031] The active element may comprise or be composed of at least one material that can absorb electromagnetic radiation with wavelengths of 850 nm and / or 1310 nm and / or 1550 nm and generate an optical signal as a result of the absorption. The material of the active element can, in particular, absorb electromagnetic radiation in the wavelength ranges of 800 nm to 900 nm and / or 1260 nm to 1360 nm (so-called original band or abbreviated as O band) and / or 1360 nm to 1460 nm (so-called extended band or abbreviated as E band) and / or 1460 nm to 1530 nm (so-called short band or abbreviated as S band) and / or 1530 nm to 1565 nm (so-called conventional band or abbreviated as C band) and / or 1565 nm to 1625 nm (so-called long band or short band) and / or 1565 nm to 1625 nm (so-called long band or abbreviated as E band) and generate an optical signal as a result of the absorption.

[0032] At least one material of the active element that absorbs electromagnetic radiation of at least one wavelength and generates an electro-optical signal as a result of the absorption is particularly preferably graphene and / or at least one dichalcogenide, in particular a two-dimensional transition metal dichalcogenide and / or a heterostructure of two-dimensional materials and / or germanium and / or at least one electro-optical polymer and / or silicon and / or at least one compound semiconductor, in particular at least one III-V semiconductor and / or at least one II-VI semiconductor, which has been proven to be particularly suitable.

[0033] In particular, the photodetector can be useful for signal conversion from the optical to the electronic world.

[0034] According to a third aspect of the present invention, a longitudinal cross-section of a waveguide including or formed by at least four longitudinally extending waveguide segments that are substantially parallel to each other, and at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or consisting of such a material, two active elements or one such active element and one electrode, one of the lower sides of the waveguide segments being disposed between the two active elements or between the one active element and the one electrode, one of the middle portions between the upper and lower sides of the waveguide segments being disposed above the two active elements or above the one active element and the one electrode, the remaining two upper sides of the waveguide segments being disposed above one of the middle portions between the upper and lower sides of the waveguide segments, and the remaining two upper sides of the waveguide segments being preferably laterally spaced apart from each other so as to form a gap extending therebetween, a modulator, in particular an electro-optic modulator, is provided.

[0035] Here, in particular, there may be a sandwich structure including, from bottom to top, an active element or electrode, then a lower waveguide segment of the longitudinal cross-section of the waveguide, then a second active element or electrode, then a middle waveguide segment of the longitudinal cross-section of the waveguide, and then two upper waveguide segments of the longitudinal cross-section of the waveguide.

[0036] A method of manufacturing such a modulator according to the present invention includes, for example, providing an active element or electrode in contact with a wafer or in contact or non-contact with a film provided on the wafer, obtaining a lower waveguide segment by preferably depositing a waveguide material, further providing an electrode on the active element or above the lower waveguide segment, obtaining a middle waveguide segment by preferably depositing a waveguide material, and forming by preferably depositing a waveguide material and then performing subsequent structuring to obtain upper waveguide segments and a gap therebetween.

[0037] The element or segment or film is disposed above or below another element or segment or another film. Here, the element or segment or film may be provided directly above or below another element or segment or another film, for example, may be in contact with the upper or lower side of another element or segment or another film, and at least one other element or segment or another film may be arranged so as to be located between them. This is applicable to photodetectors and modulators according to all aspects of the present invention.

[0038] According to a fourth aspect of the present invention, a longitudinal cross-section of a waveguide including or formed by at least five longitudinally extending waveguide segments substantially parallel to each other, and at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or consisting of such a material, two active elements or such one active element and one electrode, two of the waveguide segments below are disposed below the two active elements or below the one active element and the one electrode so as to form a gap extending therebetween, preferably being laterally spaced apart from each other, one (12c) of the upper and lower intermediate waveguide segments is disposed between the two active elements or between the one active element and the one electrode, the other of the upper and lower intermediate waveguide segments is disposed above the two active elements or above the one active element and the one electrode, and one of the upper waveguide segments is disposed above the other of the upper and lower intermediate waveguide segments. A modulator, particularly an electro-optic modulator, is provided.

[0039] The upper waveguide segment preferably has a lateral distance smaller than the lateral distance of the other waveguide segments. The lateral distances of the two lower segments and the two intermediate segments may be multiples of the lateral distance of the upper segment.

[0040] A method of manufacturing such a modulator according to the present invention comprises, for example, a step of producing by depositing a waveguide material in contact with or on a coating provided in contact with or without contact on a wafer, in particular on a wafer, a step of structuring to obtain two lower waveguide segments and a gap therebetween, a step of providing an active element or an electrode on top of them, a step of producing by preferably depositing a waveguide material to obtain a first intermediate waveguide segment, a step of providing a further active element or an electrode on top of the first intermediate waveguide segment, a step of producing by preferably depositing a waveguide material to obtain a second intermediate waveguide segment, and a step of producing, preferably by depositing a waveguide material, to obtain an upper waveguide segment and preferably performing subsequent structuring.

[0041] According to a fifth aspect of the present invention, there is provided a modulator, in particular an electro-optic modulator, characterized in that it comprises a longitudinal cross-section of a waveguide comprising or formed by at least six longitudinally extending waveguide segments that are substantially parallel to each other, and two active elements comprising or consisting of at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or such one active element and one electrode, wherein two of the lower waveguide segments are arranged below the two active elements or below one active element and one electrode and are preferably laterally spaced apart from each other to form a gap extending therebetween, one of the upper and lower intermediate waveguide segments is arranged between the two active elements or between one active element and one electrode, the other of the upper and lower intermediate waveguide segments is arranged above the two active elements or above one active element and one electrode, and the remaining two upper waveguide segments are arranged above the other of the upper and lower intermediate waveguide segments and are preferably laterally spaced apart from each other to form a gap extending therebetween.

[0042] The method of the present invention for fabricating such a modulator comprises, for example, the steps of fabricating by depositing a waveguide material in contact with, or in contact with or on a film provided in contact or non-contact on, a wafer, in particular; structuring to obtain two lower waveguide segments and a gap therebetween; providing an active element or an electrode on top of them; fabricating by preferably depositing a waveguide material to obtain a first intermediate waveguide segment; providing a further active element or an electrode on top of the first intermediate waveguide segment; fabricating by preferably depositing a waveguide material to obtain a second intermediate waveguide segment; and fabricating, preferably by depositing a waveguide material and preferably performing subsequent structuring, to obtain two upper waveguide segments and a gap therebetween.

[0043] The modulator (electro-optic modulator) can be used in particular for optical signal encoding. The modulator can also be designed as a ring modulator.

[0044] In the case of a modulator comprising two active elements, furthermore, it is preferable that the two active elements are spaced apart from each other and arranged to be offset from each other such that one of the two active elements is partially located above the other to form an overlap region. As a preferred embodiment, when the modulator comprises only one active element and one (conventional) electrode, likewise, it is preferable that the active element and the electrode are spaced apart from each other and arranged to be offset from each other such that one of them is partially located above the other to form an overlap region.

[0045] In other words, the portion of one active element and the portion of the other active element or electrode preferably align or overlap without contacting each other. Preferably, at least in the overlapping region, the two active elements or one active element and one electrode (or at least a portion thereof) extend at least substantially parallel to each other.

[0046] The overlapping region is particularly preferably arranged above or below the gap or provided therein in alignment with the gap. In this way, the optical mode (slot mode) can be guided within the slot (gap) between two waveguide segments having a high electric field strength. At the upper and lower edges of the slot, a part of the optical mode is outside the slot. In these regions, the optical mode can interact efficiently with particularly effective optical materials.

[0047] When two gaps are present, the overlapping region is made to be located above one gap and below the other gap. The two gaps and the overlapping region or portions thereof can be aligned, which has proven to be particularly suitable. According to two gaps arranged one above the other, in the region between the gaps, in particular, the proportion of the optical mode is particularly high compared to an arrangement having only one gap, which enables a particularly efficient interaction with the electro-optic material.

[0048] Furthermore, exactly one gap formed between two waveguide segments spaced apart from each other is provided before or after above the two active elements or above one active element and one electrode. Alternatively or additionally, exactly one gap formed between two waveguide segments spaced apart from each other can be provided below the two active elements or below one active element and one electrode.

[0049] In an even more particularly advantageous embodiment, the lateral distance of the overlap region corresponds to a range of 0.8 to 1.8 times, preferably 1.0 to 1.5 times, the lateral distance of the gap (at least one of the gaps).

[0050] It should be understood that the material changing its refractive index is, in particular, changing its dispersion (in particular the refractive index) and / or its absorption. The dispersion or refractive index is usually given by the real part of the complex refractive index, and the absorption is given by the imaginary part of the complex refractive index. A material whose refractive index changes as a function of the presence of voltage and / or charge and / or an electric field is, in particular, understood herein to be a material characterized by the Pockels effect and / or the Franz-Keldysh effect and / or the Kerr effect. Furthermore, materials characterized by the plasma dispersion effect are also considered to be such materials.

[0051] As at least one material of at least one active element whose refractive index changes as a function of the presence of voltage and / or charge and / or an electric field, graphene, preferably chemically modified graphene and / or at least one dichalcogenide, in particular two-dimensional transition metal dichalcogenides, and / or heterostructures of two-dimensional materials and / or germanium and / or lithium niobate and / or at least one electro-optic polymer and / or silicon and / or at least one compound semiconductor, in particular at least one III-V semiconductor and / or at least one II-VI semiconductor, have proven to be particularly suitable.

[0052] Graphene has proven to be a material particularly suitable for active elements for all five aspects of the present invention.

[0053] Electro-optic polymers are polymers that are characterized in particular by having a strong linear electro-optic coefficient (Pockels effect). A strong linear electro-optic coefficient is preferably at least 150 pm / V, preferably at least 250 pm / V, and is understood to be at least about 5 times that of lithium niobate.

[0054] There are different chalcogenides. In the context of the present invention, transition metal dichalcogenides as two-dimensional materials such as MoS2 or WSe2 have proven to be particularly suitable.

[0055] Lithium niobate and electro-optic polymers are based on electro-optics. In particular, note the Pockels effect, i.e., the electric field changes the refractive index (e.g., as the Pockels effect is used in a Pockels cell). In germanium, it is the Franz-Keldysh effect, i.e., the electric field shifts the valence electrons and the edges of the conduction band relative to each other, changing the optical properties. These effects are field-based effects. In the case of silicon or graphene, it is the charge carrier-based plasma dispersion effect, i.e., charge carriers (electrons or holes) are brought into the optical mode region (either a charged capacitor is present in an array or a diode with depleted and enriched junctions is present). The refractive index (real part of the refractive index) and absorption (imaginary part of the refractive index, leading to free carrier absorption) change with the charge carrier concentration.

[0056] Group III-V semiconductors are compound semiconductors composed of elements from Group III and Group V, and Group II-VI semiconductors are compound semiconductors composed of elements from Group II or Group 12 and Group VI elements.

[0057] Many materials are characterized by both the fact that their refractive indices change as a function of the presence of voltage and / or charge and / or an electric field, and the fact that they absorb electromagnetic radiation of at least one wavelength and generate an electrical optical signal as a result of the absorption. For example, graphene fits this description. Thus, graphene is suitable for active elements of both photodetectors and modulators. This also applies to dichalcogenides such as two-dimensional transition metal dichalcogenides, heterostructures of two-dimensional materials, germanium, silicon, and compound semiconductors, especially III-V semiconductors and / or II-VI semiconductors. For example, lithium niobate is generally only suitable for modulators. Because it is transparent, it does not match the absorption characteristics and is not suitable for use as a photodetector.

[0058] Materials that absorb electromagnetic radiation of at least one wavelength and generate an electrical optical signal as a result of the absorption, and / or materials whose refractive indices change as a function of the presence of voltage and / or charge and / or an electric field can also be referred to as electro-optically active materials. In other words, it can be said that the active element comprises or consists of at least one electro-optically active material.

[0059] At least one active element may be provided in the form of a film. The film is preferably characterized by a lateral extension that is significantly larger than the thickness by a method known per se. At least one active element may be further characterized by a square or rectangular cross-section.

[0060] At least one active element may further comprise or consist of one or more layers or coatings of at least one material whose refractive index changes and / or that absorbs. In particular, at least one active element may be formed as a film comprising several layers or coatings of one or other material.

[0061] Graphene, preferably a chemically modified graphene film, or a dichalcogenide-graphene heterostructure comprising or consisting of at least one layer of graphene and at least one layer of dichalcogenide, or a combination of at least one layer of boron nitride and at least one layer of graphene, has proven to be particularly suitable.

[0062] The active element may, for example, comprise or be provided by one or more silicon films. In this case, in particular, one or more active elements or parts thereof can form a waveguide (cross-section).

[0063] The active element may be further doped and may have doped parts or regions, for example, may be p-doped and / or n-doped, and may also include parts or regions corresponding to p-doping and / or n-doping. In addition to the p-doped region and the n-doped region, preferably an intermediate undoped region may be present or provided. This is also called a p-i-n junction, where i (intrinsic) represents being intrinsic, i.e., not doped.

[0064] In connection with the manufacture of the active element, the same process as described above in connection with the gate electrode can be used.

[0065] This also includes a transfer process. That is, in particular, each active element is not, for example, monolithically manufactured on a film, but is manufactured separately and transferred, in other words, it may be transferred. Regarding the transfer process of graphene, see the papers by Li et al., "Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils", Science 324, 1312, (2009) and the papers by Bae et al., "Roll-to-roll production of 30-inch graphene films for transparent electrodes", Nature Nanotech 5, 574-578 (2010) or the paper on lithium niobate, "Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages", Nature volume 562, pages 101104 (2018) or the paper on GaAs, "Transfer print techniques for heterogeneous integration of photonic components", Progress in Quantum Electronics, Volume 52, March 2017, Pages 1-17. etc. One of these processes can also be used in the context of the present invention to obtain one or more graphene or LiNbO or GaAs films or films. Following the transfer process, structuring can be performed.

[0066] On the upper side, and preferably in contact with at least one active element, a passivation film and / or a cladding can be further provided. The cladding is particularly suitable for somewhat reducing the refractive index contrast or is designed such that the roughness on the sidewalls usually does not have a very strong influence so that losses return into the waveguide. The passivation coating preferably serves the purpose of protecting the device or circuit from the influence of the environment, in particular water. The passivation film can consist of, for example, a dielectric material, and aluminum oxide (Al 2 O 3 ) and silicon dioxide (SiO 2 ) have proven to be particularly suitable.

[0067] The final passivation film on the upper side advantageously has an opening or a relay to the contact on the lower side in order to enable an electrical connection. The opening or relay in the passivation film can be obtained, for example, by lithography and / or etching, in particular reactive ion etching.

[0068] Each active element can be connected to a contact or a contact element on one or the other side in each case. The contact or the contact element can contact a connection element, in particular a via. Via the connection element, for example, a connection from the FEOL of the chip or wafer to one or more integrated electronic components can be achieved. The term "connected" is intended to mean an electrical connection.

[0069] In particular, in the case of a photodetector having only one active element, this active element preferably contacts two contacts or contact elements located on the opposite sides, and in the case of a modulator having two active elements or one active element and one electrode, it should be noted that they are each made to contact a contact or a contact element. This contact is preferably made at an end region or an end away from the region where they at least partially overlap.

[0070] At least one of the active element or a plurality of active elements is disposed expediently so as to be at least partially exposed to an evanescent field of electromagnetic radiation guided in the waveguide with respect to a longitudinal cross-section of the waveguide. Preferably, at least one of the active elements disposed at a distance of, for example, 10 nm from the longitudinal cross-section of the waveguide is disposed at a distance of 50 nm or less, more preferably 30 nm or less.

[0071] More preferably, the active element or at least one of the active elements is characterized by a longitudinal distance in the range of 5 to 500 micrometers (μm).

[0072] Also, the active element or at least one of the active elements can also extend at least partially inside, for example, between two segments thereof, above and / or inside the longitudinal cross-section of the waveguide.

[0073] In a further advantageous embodiment, at least one of the active element or the active elements is disposed in contact or non-contact on the upper side of the waveguide in a region of the longitudinal cross-section of the waveguide having at least substantially a trapezoidal cross-section, preferably following the trapezoidal shape. Alternatively or additionally, at least one of the active element or the active elements is disposed in contact or non-contact on the upper side of a planarizing coating in a region of the planarizing coating having at least substantially a trapezoidal cross-section as seen from a transverse cross-section, preferably following the trapezoidal shape.

[0074] In the waveguide, a part of the electromagnetic radiation, particularly light, is guided as evanescent light outside the waveguide. The interface of the waveguide is a dielectric, and thus the intensity distribution is described by boundary conditions according to Maxwell with exponential decay. When an electro-optically active material, such as graphene, is disposed on or near the waveguide of the evanescent field, photons can interact with the material, particularly graphene.

[0075] There are four effects in graphene that result in a photocurrent. One is the bolometric effect, according to which the absorbed energy increases the resistance of graphene and decreases the applied direct current. The change in the direct current is the optical signal. Another effect is photoconductivity. The absorbed photons increase the charge carrier concentration, and the additional charge carriers decrease the resistance of graphene due to the proportionality of resistance to the charge carrier concentration. The applied direct current increases, and the change is the optical signal. As another effect, there is also the thermoelectric effect, according to which a thermoelectric voltage is generated from the pn junction and the temperature gradient in this junction due to the different Seebeck coefficients in the p and n regions. The temperature gradient results from the energy of the absorbed optical signal. This thermoelectric voltage is the signal. The fourth effect is due to the separation of electron-hole pairs excited in the pn junction. The resulting photocurrent is the signal.

[0076] In the case of a modulator, as described above, for this purpose, an electrically controlled electrode and an active element appropriately insulated for this purpose can include or consist of at least one material whose refractive index changes as a function of voltage or charge or electric field, in particular graphene. By using a corresponding material, in particular graphene, for the electrodes as well, as a result, during operation, two active elements come together in the evanescent field to perform an electro-optical function. For example, graphene can change its optical properties by means of a control voltage. In the particularly advantageous case of a graphene-dielectric-graphene arrangement, capacitance is generated and the two graphene films influence each other. The voltage charges the capacitance consisting of the graphene electrodes forming the two active elements, and electrons occupy states in the graphene. As a result, the Fermi energy (the energy of the last occupied state in the crystal) shifts to a higher energy (or a lower energy due to symmetry). When the Fermi energy reaches half of the energy of the photon, the free states required for the absorption process are already occupied with the correct energy, so it is no longer absorbed. Therefore, in this state, since absorption is prohibited, graphene is transparent. By changing the voltage, before and after that, graphene can be switched between absorption and transparency. A continuously shining laser beam is modulated in its intensity and can thus be used for information transmission. Similarly, the real part of the refractive index changes with the control voltage. By changing the voltage, the phase position of the laser can be modulated via the changing refractive index, and thus phase modulation can be achieved. Preferably, the phase modulation operates in a range where all states are occupied until they exceed half of the photon energy, such that graphene is transparent, the real part of the refractive index shifts significantly, and changes in absorption play a minor role.

[0077] Furthermore, the following can be further applied in relation to both the photodetector according to the first and second aspects of the present invention and the modulator according to the third, fourth, and fifth aspects.

[0078] A waveguide or its longitudinal cross-section is, in particular, an element or configuration that guides electromagnetic waves, in particular light. To guide electromagnetic waves, a wavelength-dependent cross-section of a material that is optically transparent at least for this wavelength and also distinguishable from adjacent materials that are also transparent for this wavelength is advantageously provided by a refractive index contrast. When the refractive index of the surrounding material is low, light is guided into regions of higher refractive index. In a particular case of the slit mode, two regions of high refractive index are separated from a narrow region of low refractive index with respect to the wavelength, and light is guided into the region of low refractive index. To achieve low loss due to scattering, a low sidewall roughness is advantageous.

[0079] Generally, one or more waveguides are provided, for example, on a chip or a wafer. A part of the photodetector or modulator according to the present invention is usually only a longitudinal part of the photodetector or modulator, which is a longitudinal part extending under the latter's active element. Of course, it is not excluded that a waveguide over its entire length is considered to be part of the photodetector or modulator according to the present invention. In other words, in addition to the longitudinal cross-section of the waveguide, especially the one extending under the active element, such a waveguide can also include the remaining part of the latter.

[0080] Regarding the dimensions of the waveguide, for example, the following can apply. The thickness is preferably in the range of 150 nanometers (nm) to 10 micrometers (μm). In particular, the width and length of the waveguide can also be in the range of 100 nanometers and 10 micrometers.

[0081] The waveguide can be characterized, for example, by a rectangular or square cross-section and formed as a strip waveguide applied to the longitudinal cross-section of such a waveguide. The waveguide can alternatively or additionally be formed as a ridge waveguide having a T-shaped cross-section. Furthermore, alternatively or additionally, it is also possible for the waveguide to be provided by a slot waveguide.

[0082] The waveguide or longitudinal cross-section of such a waveguide can include several parts or segments within the cross-section, for example, it can be formed into several parts including, or consisting of, a first, for example, lower or left, and a second, for example, upper or right segment. One or more waveguide segments can be characterized by a rectangular or square cross-section. Also, one or more segments of the waveguide can be characterized by a tapered cross-section and / or, at least in part, by an enlarged cross-section.

[0083] When the waveguide comprises or is composed of two or more segments, these can be adjacent to each other or fit together, or they can be spaced apart from each other, for example, to form at least one gap or slot.

[0084] The longitudinal cross-section of the waveguide includes or consists of at least one material that is transparent to electromagnetic radiation with wavelengths of 850 nm and / or 1310 nm and / or 1550 nm in particularly useful embodiments both for the above-described photodetector according to the first and second aspects of the present invention and for the above-described modulator according to the third, fourth and fifth aspects of the present invention. Such materials are particularly preferably transparent to electromagnetic radiation in the wavelength ranges of 800 nm to 900 nm and / or 1260 nm to 1360 nm (so-called original band or abbreviated as O band) and / or 1360 nm to 1460 nm (so-called extended band or abbreviated as E band) and / or 1460 nm to 1530 nm (so-called short band or abbreviated as S band) and / or 1530 nm to 1565 nm (so-called conventional band or abbreviated as C band) and / or 1565 nm to 1625 nm (so-called long band or abbreviated as L band). These bands are known in the field of communication engineering.

[0085] As materials for the longitudinal cross-section of the waveguide, for example, titanium dioxide and / or aluminum nitride and / or tantalum pentoxide and / or silicon nitride and / or aluminum oxide and / or silicon oxynitride and / or lithium niobate and / or silicon, particularly polysilicon and / or indium phosphate and / or gallium arsenide and / or indium gallium arsenide and / or aluminum gallium arsenide and / or at least one dichalcogenide, particularly two-dimensional transition metal dichalcogenides and / or chalcogenide glass and / or heterostructures of two-dimensional materials and / or resins or resin-containing materials, particularly SU8 and / or polymers or polymer-containing materials, particularly OrmoClad and / or OrmoCore have been proven to be particularly suitable. In this regard, the longitudinal cross-section of the waveguide may include one or more of these materials, may include one of these materials, or may include a combination of two or more of these materials. This can apply to only one, or a plurality, or possibly all of the waveguide segments in each case.

[0086] When the longitudinal cross-section of the waveguide comprises a plurality of waveguide segments, these may all comprise the same material or may be composed of the same material. However, of course, it is also possible for two or more segments to differ with respect to their materials. For example, at least one waveguide segment can be characterized by a refractive index greater than that of at least one other waveguide segment. For example, when some waveguide segments are in a sandwich-like or laminated configuration, the outer segments can have a lower refractive index. In this case, light is focused towards the center of the waveguide arrangement. A purely exemplary material is an upper and a lower segment of aluminum oxide with an intermediate segment of titanium dioxide.

[0087] A higher refractive index has been proven to be advantageous for the waveguide segment placed between the two active elements as compared to the remaining segments. This is because the light is thereby focused within the area of the active element.

[0088] Different materials of the waveguide segment (at least part thereof) can be advantageous because they are characterized by different etching rates. This results in advantages in manufacturing, for example, when providing the required structuring.

[0089] Regarding the manufacture of the longitudinal section of the waveguide, the manufacture of the waveguide material may in particular be carried out by any of deposition, spin-on, transfer, and then, preferably, the structuring of the applied waveguide material is carried out in particular by lithography and / or reactive ion etching (RIE). For example, the same deposition process as described above in connection with the gate electrode can be used.

[0090] The waveguide or the longitudinal section can be formed on one or more components. In particular, when viewed in cross-section, it may be formed from several waveguide segments or may include several waveguide segments. These can be spaced apart from each other, or, for example, one segment can be manufactured directly on top of another segment, for example by applying manufacture by deposition of material, and thus directly face each other and can also be in contact with each other.

[0091] The longitudinal section of the waveguide may further preferably consist of at least one material whose refractive index is different from that of the surrounding material or may include at least one such material.

[0092] When a waveguide or a longitudinal cross-section of a waveguide includes two or more segments, at least two of which are spaced apart from each other to form a gap, the gap can be provided as an advantageous embodiment to be filled with at least one dielectric material having a refractive index lower than the refractive index of the material of the waveguide segments defining the gap.

[0093] The longitudinal cross-section of the waveguide may be surrounded, for example, by a planarizing coating on one or more sides. In such a case, a pair of pure refractive indices is 3.4 (Si) for the longitudinal cross-section of the waveguide and 1.5 (SiO 2 ) for the planarizing film. If it is a dielectric, it is 2.4 (TiO 2 ) for the longitudinal cross-section of the waveguide and 1.5 (SiO 2 ) for the planarizing film, or 2.0 (Sin) for the longitudinal cross-section of the waveguide and 1.47 for the planarizing film.

[0094] It is particularly preferable that the refractive index of the longitudinal cross-section of the waveguide is at least 20%, preferably at least 30% greater than the refractive index of the surrounding material.

[0095] The longitudinal cross-section of the waveguide may further be disposed in contact or non-contact on the upper side of the planarizing coating.

[0096] Preferably, the planarizing coating is at least partially characterized by a roughness in the range of 1.0 nm RMS to 0.1 nm RMS, particularly 0.6 nm RMS to 0.1 nm RMS, preferably 0.4 nm RMS to 0.1 nm RMS, on the side where the longitudinal cross-section of the waveguide is disposed thereon. Note that nm is an abbreviation for nanometer (10 -9 ).

[0097] Alternatively or additionally, the longitudinal cross-section of the waveguide can be embedded at least in part in the planarization coating, and the active element(s) (in the case of a modulator having two such elements, one active element) is arranged on top of the planarization coating. In this case, the planarization coating is preferably characterized, on the side where the active elements are arranged on top thereof, by a roughness in the range of from 1.0 nm RMS to 0.1 nm RMS, in particular from 0.6 nm RMS to 0.1 nm RMS, preferably from 0.4 nm RMS to 0.1 nm RMS, at least in part.

[0098] If the longitudinal cross-section of the waveguide is arranged on top of and embedded in the planarization coating, there are two planarization coatings.

[0099] To achieve an appropriate roughness, for example, chemical mechanical polishing and / or resist planarization can be carried out.

[0100] In chemical mechanical polishing, the object to be polished is usually polished by a rotational movement between polishing pads. The polishing is carried out chemically on the one hand and physically by a polishing paste on the other hand. By combining chemical and physical actions, a smooth surface with a roughness of less than a nanometer can be obtained.

[0101] In particular, resist planarization includes the formation of a single or repeated spin-on-glass coating and subsequent etching, preferably reactive ion etching (RIE). When planarizing a surface such as a surface with height differences, this can be done by forming and etching a spin-on-glass coating. The spin-on-glass coating partially compensates for the height differences. That is, the recesses formed on the surface have a coating thickness higher than that of the adjacent portions after the formation of the spin-on-glass coating. Spin-on-glass and, for example, SiO 2 For a surface like that, this can be done by forming and etching a spin-on-glass coating. The spin-on-glass coating partially compensates for the height differences. That is, the recesses formed on the surface have a coating thickness higher than that of the adjacent portions after the formation of the spin-on-glass coating. Spin-on-glass and, for example, SiO 2The etching rate is similar or identical in the applied RIE process. Here, application means that, in particular, the pressure, gas flow rate, composition of the gas mixture, and power are selected accordingly. When the entire spin-on glass film is etched by RIE after the formation of the spin-on glass film, it has been shown that the height difference decreases due to the flattening effect of the spin-on glass film. The height difference can be further reduced by repetition. SiO 2 When depositing the coating, the consumed SiO 2 coating thickness must be taken into account, and after completing the final etching process, the desired SiO 2 coating thickness is achieved. It should be emphasized that resist flattening is not limited to SiO 2 and other materials can also be considered. It is convenient if the etching rate of the material is the same as or at least substantially the same as the etching rate of the spin-on glass. This condition is met in the case of SiO 2 and spin-on glass. For example, it should be noted that materials with an etching rate twice different from that of the spin-on glass are also possible, and in that case, generally several passes are required. Hydrogen silsesquioxane and / or polymer can be applied, for example, as a liquid material, especially by spin-on. Since it vitrifies during subsequent annealing, it is called spin-on glass. Hydrogen silsesquioxane (HSQ) is a kind of inorganic compound having the formula [HSiO 1.5 n.

[0102] Chemical mechanical polishing and / or resist flattening can be carried out, in particular, in such a way that a roughness in the range of 1.0 nm RMS to 0.1 nm RMS, in particular 0.6 nm RMS to 0.1 nm RMS, preferably 0.4 nm RMS to 0.1 nm RMS can be obtained.

[0103] The roughness within the above range has been proven to be particularly appropriate. They are advantageous, in particular, for avoiding stress and strain in the upper layer. In this regard, reference can be made to the paper "Identifying suitable substrates for high-quality graphene-based heterostructures" by L. Banszerus et al, 2D Mater. vol. 4, no. 2, 025030, 2017.

[0104] In the photodetector according to the first aspect of the present invention, the dielectric layer, which may be provided particularly between the gate electrode and the active element, should be noted that it may be obtained in the same manner if its upper side is characterized by the roughness within the above range, for example, by CMP and / or resist planarization.

[0105] The atomic force microscope (AFM) can be used as a measurement method for determining roughness, particularly as described in the EN ISO 25178 standard. The atomic force microscope is discussed particularly in Part 6 (EN ISO 25178-6:2010-01) of this standard, which deals with the measurement method of roughness.

[0106] Furthermore, the planarization coating and / or additional planarization coating provided as required are preferably provided on the surface that has undergone the planarization process and may include, for example, one or more cover layers that may be a dichalcogenide layer or a dichalcogenide heterostructure, or a boron nitride layer. These materials are preferably deposited or transferred without the need for further chemical mechanical polishing or further resist planarization, although the possibility of chemical mechanical polishing and resist planarization cannot be excluded.

[0107] In addition, each planarizing film may be obtained by coating or may be obtained in advance as a film. In principle, the same processes (CVD, PVD, atomic layer deposition, transfer) used for the planarizing coating described above in relation to the gate electrode can be used. This and the following descriptions for planarizing coatings can also be applied to the dielectric layer if present.

[0108] The film can comprise exactly one or a plurality of layers. It may be composed of only one material or may contain a plurality of materials. For example, the film can comprise two or more layers of two or more different materials. Of course, the film can have a plurality of layers, all made of the same material. More than one layer can be obtained by providing layers such as several atomic layers for its manufacture, for example by deposition.

[0109] The planarizing film may further comprise or consist of spin-on glass and / or at least one polymer and / or at least one oxide, in particular silicon dioxide and / or at least one nitride. Spin-on glass is generally a liquid substance that can coat a wafer by spin-on. After spin-on, a film is formed on the wafer, the thickness of which depends on the surface unevenness. Thus, the depth is partially smoothed and the formation of the spin-on glass film has a planarizing effect. Spin-on glass is usually heated after deposition and thus becomes a glassy film.

[0110] In particular, the modulator may be made to further comprise a diode or a capacitor. For example, the present invention may be an integrated III-V semiconductor modulator as described in the paper “Heterogeneously integrated III-V / Si MOS capacitor Mach-Zehnder modulator” from Hiaki, Nature Photonics volume 11, pages 482-485 (2017).

[0111] When a diode is provided, it may in particular comprise a plurality of coatings of, for example, InGaAsP compositions in order to produce the pn junction and the two contact regions.

[0112] The subject matter of the present invention is also a semiconductor device comprising a chip and at least one, preferably a plurality of, photodetectors and / or modulators according to the invention, wherein one or more photodetectors are preferably arranged on the chip or on a coating arranged in contact or non-contact on or on the chip.

[0113] Finally, the present invention relates to a semiconductor device comprising a wafer and at least one, preferably a plurality of, photodetectors and / or modulators according to the invention, wherein one or more photodetectors and / or modulators are preferably arranged on the wafer or on a coating arranged in contact or non-contact on the wafer.

[0114] The photodetector and / or modulator may be, for example, part of a photonics platform manufactured on or bonded to the chip or wafer.

[0115] Bonding means in particular that the photodetector and / or modulator is not manufactured on the chip or wafer, but after being manufactured separately from the chip or wafer, is probably combined with the chip or wafer as part of a larger unit, for example by using a suitable intercoat.

[0116] When looking at a chip or wafer in cross-section, its vertical structure can be divided into different sub-regions. The bottommost is the Front End of Line, abbreviated as FEOL, which usually contains one or more integrated electronic components. The integrated electronic components may be, for example, transistors and / or capacitors and / or resistors. Above the Front End of Line is the Back End of Line, abbreviated as BEOL, which usually has various metal layers that serve as means for interconnecting the integrated electronic components of the FEOL.

[0117] Following dicing / splitting / fragmentation, the wafer contains a plurality of regions, each of which forms a chip or die. These regions are also called chip or die regions. Each chip region of the wafer preferably includes a cross-section or partial cross-section of a specific single-piece semiconductor substrate of the wafer. Preferably, each chip region further includes one or more integrated electronic components that extend within and / or above the corresponding region of the semiconductor substrate, especially when viewed in cross-section within the FEOL. It should be emphasized that the chip regions do not represent individual chips, i.e., the wafer does not contain individual chips.

[0118] Regarding both the semiconductor device and the semiconductor device according to the present invention, it is effective to include a plurality of identically designed photodetectors and / or a plurality of identically designed modulators according to the present invention, or a plurality of photodetectors of different designs and / or a plurality of modulators of different designs according to the present invention. Also, there may be several identical photodetectors and / or modulators, and further one or more photodetectors and / or modulators of different designs.

[0119] Regarding the embodiments of the present invention, reference is made to the accompanying drawings and also to the description of several of the following embodiment examples, not only the dependent claims of the claims.

Brief Description of the Drawings

[0120]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0121] All the figures show purely schematic views. In the figures, the same reference numerals are assigned to the same components or elements.

[0122] FIG. 1 shows a partial cross-sectional view through one embodiment of a semiconductor device according to the present invention.

[0123] It includes a wafer (1), a planarization film (2) formed on the wafer (1), and a plurality of photodetectors (3) formed on the planarization film (2). In the partial cross-sectional view shown in FIG. 1, only one of the plurality of photodetectors (3) is exemplarily shown.

[0124] The wafer (1) comprises a single-piece semiconductor substrate (4) and, in the example shown, a plurality of integrated electronic components (5) extending within the semiconductor substrate (4). The integrated electronic components (5) may in particular be transistors and / or resistors and / or capacitors and are only shown schematically in Figure 1 by the hatched lines marked with the reference sign 5. At the corresponding positions within the substrate (4), a large number of integrated electronic components (5) are shown in a known manner. These may also be components of a processor such as a CPU and / or a GPU, and such components of a processor may be formed in a known manner.

[0125] The wafer (1) has a front end of line (abbreviated as FEOL (6)) in which a plurality of integrated electronic components (5) are arranged, and a back end of line (abbreviated as BEOL) (7) which is above the FEOL and in which the integrated electronic components (5) of the FEOL are interconnected by different metal surfaces. The integrated electronic components (5) within the FEOL (6) and the associated interconnections within the BEOL (7) form the integrated circuit of the wafer (1) in a method that is well known in advance. The FEOL (6) may also be called the transistor front end, and the BEOL (7) may also be called the metal back end. The metal surfaces comprise a plurality of connection elements (8), which in this case are provided by vertical interconnect accesses (abbreviated as VIA). The VIA (8) is made of a metal such as copper, aluminum or tungsten.

[0126] The planarization coating is manufactured on the upper surface (9) of the wafer (1) facing away from the FEOL (6) and is made of a dielectric material. In this case, the planarization coating (2) is made of silicon dioxide (SiO 2 ) but this should be understood as exemplary and other materials can also be used.

[0127] In the illustrated embodiment, the planarization coating (2) is the corresponding coating material (in this case SiO 2It is a coating obtained by the deposition of ) and subsequent planarization of the deposited material on the upper side (10) facing away from the wafer. By planarizing the deposited material on the upper side (10) facing away from the wafer, the planarized film (2) is currently characterized by an RMS roughness of 0.2 nm, which should be understood as exemplary.

[0128] In the illustrated example, the planarized film (2) extends over the entire upper surface (9) of the wafer (1). The material of the planarized film (2) is deposited over the entire upper surface (9) of the wafer (1). Accordingly, the planarized film (2) is characterized by having a diameter that at least substantially corresponds to the diameter of the wafer (1).

[0129] The photodetector (3) fabricated on the planarized film (2) is an embodiment of the photodetector (3) according to the first aspect of the present invention. In the embodiment, these photodetectors (3) are all identical in structure, although this should not be understood in a limiting sense.

[0130] Hereinafter, the design and manufacture of the photodetectors (3) will be described by way of example based on one photodetector (3) shown in FIG. 1. Also, with respect to further embodiments of photodetectors and modulators described further below (see FIGS. 3 to 6), the design is described based on an example shown in a partial cross-section.

[0131] (Each) photodetector (3) includes one longitudinal cross-section (12) of the waveguide (11), that is, the longitudinal cross-section overlapped by the active element (13) of the photodetector (3). In FIG. 2, the active element (13) and the waveguide (11) below it are shown in a purely schematic top view, where the longitudinal cross-section (12) of the waveguide covered by the active element (13) is indicated by a dashed line.

[0132] The dielectric used also in the illustrated embodiment, preferably titanium dioxide, is particularly suitable as a waveguide material. Alternatively or additionally, one or more waveguides made of aluminum nitride and / or tantalum pentoxide and / or silicon nitride and / or aluminum oxide and / or silicon oxynitride and / or lithium niobate, or of a semiconductor such as silicon, indium phosphate, gallium arsenide, indium gallium arsenide, aluminum gallium arsenide, a dichalcogenide or a chalcogenide glass, or of a polymer such as SU8 or OrmoClad or OrmoCore are possible.

[0133] The longitudinal cross-section (12) of the waveguide here is formed by two waveguide segments (12a)(12b) which extend longitudinally, are at least substantially parallel to each other and are laterally (from left to right or vice versa in the figure) spaced apart from each other, forming a gap (14) extending between them. Thus, it is a slot waveguide. With such a waveguide (11), the optical mode is guided within the gap (14) during operation. In the example shown, the two waveguide segments are characterized by a rectangular cross-section. The gap (14) can be filled, for example, with SiO 2 and can be filled with.

[0134] The two waveguide segments (12a)(12b) are each in contact, on at least one side, in this case the side facing the active element (13), with the silicon gate electrodes (15a)(15b). The gate electrodes (15a)(15b) are formed by silicon coats fabricated on the respective waveguide segments (12a)(12b).

[0135] The active element (13) comprises or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical optical signal as a result of the absorption. In the illustrated example, it is provided by the graphene film (13). Graphene may also change its refractive index (refractivity and / or absorptivity) as a function of voltage and / or charge and / or electric field. The active element (13) may be provided by a film comprising or consisting of a dichalcogenide-graphene heterostructure comprising or consisting of at least one other or additional electro-optically active material, for example at least one layer of graphene and at least one layer of dichalcogenide, or by a film comprising at least one layer of boron nitride and at least one layer of graphene, which should be emphasized.

[0136] As can be seen from FIG. 1, the graphene film (13) is arranged on the upper side (16) of a further planarizing coating (17) in which the waveguide (11) and thus its longitudinal section (12) are embedded. This further planarizing coating (17) consists of the same material as the planarizing coating (2) and is characterized by having the same roughness as the upper side (10) of the planarizing coating (2) on its upper side (16). However, this should be understood by way of example only and is not limiting.

[0137] By means of the gate electrodes (15a)(15b) provided on the waveguide segments (12a)(12b), a pn junction can be realized within the graphene film (13) in the region extending above the gap (14), and thus within the region of the optical mode guided during operation in the gap (14) of the waveguide (11). The pn junction can be used to separate the electron-hole pairs generated by absorption in order to generate a photocurrent. Similarly, the thermoelectric effect can be utilized in graphene, where a Seebeck coefficient of opposite sign is generated in the p and n regions and a thermoelectric voltage is generated when heated by the absorbed energy (photons).

[0138] Note that the connection of the gate electrodes (15a) and (15b) for the power supply (not shown) can be arranged horizontally adjacent to the VIA (8), for example.

[0139] The photodetector (3), in particular its graphene film (13), is electrically connected to at least one of the integrated electronic components (5) in the FEOL (6) of the wafer (1). As can be seen in the schematic cross-sectional view according to FIG. 1, the connection is realized not only by the VIA (8) in the BEOL (7) of the wafer (1), but also by a further VIA (8) that extends through the planarization coating (2) and any further coating or element present thereon (in this case, a further planarization coating (17)).

[0140] Specifically, the graphene film (13) is electrically connected, in the opposite end region, directly or via a connecting element (18), to the upper end of the VIA (8) that extends to the planarization coating (2) and the BEOL (7) of the wafer (1) through the further planarization coating (17). In the top view of FIG. 2, the VIA (8) that is below the connecting element (18) and connected to the connecting element (18) is shown as a thin line.

[0141] In the illustrated embodiment, a passivation coating (19) containing and / or composed of aluminum oxide (Al 2 O 3 ) and / or silicon dioxide (SiO 2 ) is provided on the upper side of the graphene film (13).

[0142] The photodetector (3) shown in FIGS. 1, 3, and 4 and described below can itself be used in a known manner, especially for signal conversion from the optical to the electronic world.

[0143] To obtain the semiconductor device shown in FIG. 1, in a first step S1 (see FIG. 8), the wafer (1) is provided with an integrated circuit including a metallization including the integrated electronic components (5) and the VIA (8). The wafer (1) can be any conventional type of wafer (1) obtained by a known processing process.

[0144] In the second step S2, the planarization film (2) is manufactured on the upper side of the BEOL (7) of the wafer (1). For this purpose, in this case, as the coating material, silicon dioxide (SiO 2 ) is deposited, and for example, chemical vapor deposition such as low-pressure chemical vapor deposition or plasma-enhanced chemical vapor deposition, or physical vapor deposition, or spin-on glass is used. In this embodiment, PECVD is used. After depositing the coating material, the upper side of the obtained coating is planarized (step S3), and in this case, resist planarization is performed to obtain an upper side (10) having an RMS of 0.2 nm.

[0145] Resist planarization includes single or repeated spin-on glass spinning and subsequent etching (the etching in practice is reactive ion etching (RIE)). The spin-on glass film partially compensates for the height difference, that is, the recess formed on the surface has a film thickness higher than that of the adjacent part after the formation of the spin-on glass film. After the formation of the spin-on glass film, for example, by RIE, when the entire spin-on glass film is etched, the height difference is reduced due to the planarization effect of the spin-on glass film. By repeating, the height difference can be further reduced so as to obtain the desired roughness. It should be noted that the upper side (10) of the planarization film (2) corresponding to the low roughness can alternatively be obtained, for example, by chemical mechanical polishing (CMP).

[0146] In the next step S4, which represents the first step in the manufacture of the photodetector (3), the (respective) waveguide (11) with the gate electrodes (15a)(15b) is manufactured. For this purpose, the waveguide material, currently titanium dioxide (TiO 2 ) is deposited, in particular, over the entire upper side (10) of the obtained planarization film (2). The deposition can be performed by PVD or CVD, in particular PECVD or LPCVD, or atomic layer deposition (ALD) which can also be performed by spin-on in the same manner as the planarization film, or by executing a transfer printing process. Also, LPCVD is used in the same manner as the formation of the planarization film (2).

[0147] Subsequently, as the coating material for the gate electrodes (15a) (15b), the gate electrode material, in this case silicon, is deposited by a PVD or CVD process and preferably two-dimensionally.

[0148] Lithography and in particular structuring by reactive ion etching (RIE) is carried out to obtain individual waveguides (11) having individual waveguide segments (12a) (12b) with gaps (14) and individual gate electrodes (15a) (15b).

[0149] In the next step S5, a further planarization coating (17) is formed on the waveguide (11) on which the gate electrodes (15a) (15b) are provided on its upper side and on the upper side (10) of the planarization coating (2). This is obtained by deposition by PECVD and resist planarization in a manner completely analogous to the planarization coating (2). During or for the material deposition, the gap (14) is also filled with SiO 2 As a result of the resist planarization, the cross-section of the further planarization coating (17) on the upper side of the waveguide (11) is trapezoidal (see FIG. 1).

[0150] Also, for the further planarization coating (17), other processes of the above process can be used instead of LPCVD and CMP, and other planarization treatments such as the CMP described above for the planarization coating (2) and / or further planarization are possible.

[0151] The planarization coating (2) and the further planarization coating (17) are preferably provided on the surface to be planarized and may include one or more coating layers which may be, for example, a dichalcogenide layer or a dichalcogenide heterostructure, or a boron nitride layer. These materials are preferably deposited or transferred without the need for further chemical mechanical polishing or further resist planarization, but are not limited thereto.

[0152] For the sake of completeness, it should be noted that in the case of regions where the semiconductor device of the present invention does not have a further planarization coating (17), for example, regions where the structure corresponds to those in FIGS. 3 to 6, the further planarization coating (17) (and any coating disposed thereon) is then partially removed again, in particular by lithography and etching.

[0153] In step S6, the VIA (8) is manufactured through the planarization coating (2) and the further planarization coating (17). In principle, this can be done by any method known from the prior art. In particular, the regions where they are extended are first preferably defined by lithography and dry chemically etched by RIE. Then, metallization is performed and the metallized surface is structured, for example, by CMP (damascene process) or lithography - and RIE. The VIA (8) can be manufactured after the further planarization coating (17) is formed through both planarization coatings (2) (17), or after a portion of the first planarization coating (2) is formed through the first planarization coating (2) and a portion of the second planarization coating (17) is formed through the second planarization coating (17).

[0154] In step S7, the active elements of the (respective) photodetector (3) provided by the graphene film (13) are provided on the upper side (16) of the further planarization coating (17), for example, deposited on the upper side (16).

[0155] The deposition of the graphene film (13) of the (respective) photodetector can be performed, for example, by a transfer process as described above. Then, in particular, in each case, a graphene film manufactured on a separate substrate or a separate metal foil or a separate germanium wafer is transferred to the further planarization coating (17). Also, it is possible for the (respective) graphene film (13) to be manufactured directly on the further planarization coating (17). This can include, for example, material deposition.

[0156] When a transfer process is used, the passivation film can already be provided on top of each graphene film (13), or it may be transferred, for example, after being deposited on the graphene film (13). Also, the passivation film may be deposited such that it is deposited after the graphene film (13) is transferred or manufactured.

[0157] First, it is also possible to manufacture an overall area graphene film and / or an overall area passivation film extending over the entire surface of the further planarization film (17) on top of the further planarization film (17). In this case, in order to obtain individual graphene films (13) as active elements of several photodetectors (3), structuring by lithography and RIE is performed in particular.

[0158] Next, the connection elements (18) are preferably manufactured by depositing metal on the entire surface and then structuring by lithography and RIE to obtain individual connection elements (18) (step S8).

[0159] In step S9 before the final step, preferably Al 2 O 3 and / or SiO 2 upper passivation coating (19) is deposited. In this coating, the openings are conveniently manufactured by lithography - and RIE, in particular for the connection elements (step S10). Preferably, the openings are formed in contact elements that serve to connect photonics and / or electronics to the outside.

[0160] Figure 3 shows a further embodiment of the photodetector (3) according to the first aspect of the present invention.

[0161] This embodiment is essentially different from that shown in FIG. 1. The two waveguide segments (12a) and (12b) of the longitudinal cross-section (12) of the waveguide (11) do not have a rectangular cross-section, and there is no additional planarization coating (17). Instead, an active element exemplified by a graphene film (13) is disposed on a dielectric coating (not visible in the figure) provided above the gate electrodes (15a) and (15b). The dielectric coating represents a gate dielectric. It is characterized by an RMS roughness of 0.2 nm on its upper side. Its thickness is 15 nm, and these two values should be understood purely as examples.

[0162] As can be seen from the figure, each of the two waveguide segments (12a) and (12b) has an end region facing a gap (14) extending between the two segments (12a) and (12b), and its cross-section partially expands in the direction of the gap (14). As can be seen from the figure, the two end regions and the gap (14) form a central trapezoidal region. The portions or regions of the segments (12a) and (12b) adjacent to this trapezoidal region on both sides are characterized by a certain thickness as can be seen.

[0163] The two gate electrodes (15a) and (15b) extend horizontally only over the upper cross-section of their respective segments (12a) and (12b).

[0164] In FIG. 3, VIAs (8) that contact each gate electrode (15a) (15b) in relation to the gate electrodes (15a) (15b) can be seen. Through these, it is connected to at least one integrated electronic component (5) from the FEOL (6), but this connection is not visible in the figure for reasons of simplified representation. As can be seen from the figure, these VIAs (8) extend through the planarization coating (2) and the waveguide segments (12a) (12b) where each gate electrode (15a) (15b) is disposed in each case. The voltage supply to the gate electrodes (15a) (15b) is ensured via the VIAs (8). Also in the example shown in FIG. 3, during operation, a pn junction can be obtained through the gate electrodes (15a) (15b) within the graphene film (13), and a pn junction can be obtained in the region extending above the gap (14) where the optical mode is guided during operation.

[0165] To obtain the arrangement according to FIG. 3, steps S1 to S3 may be the same as those for the manufacture of the arrangement of FIG. 1.

[0166] In step S4, an etching process, particularly an RIE process, adapted for the manufacture of the waveguide (11) and the gate electrodes (15a) (15b), is performed to obtain a trapezoidal region with beveled edges, for example, in the same manner as described above in relation to FIG. 1. The isotropic etching behavior of the RIE process can be obtained, for example, by increasing the process pressure and the mixing of the appropriate gases compared to an anisotropic etching process. An increased process pressure of, for example, 20 mTorr compared to 10 mTorr gives a component that is not directed in the etching process, which results in a higher removal rate at the upper edge due to a longer etching time. Subsequently, first, the VIAs (8) for the gate electrodes (15a) (15b) are manufactured, and then, again, a material for the gate electrodes (15a) (15b), such as silicon, is deposited.

[0167] Next, the (respective) gaps (14) and the gate electrodes (15a) (15b) are etched. As a result, the gate electrode coating, which was initially continuous over the entire surface, is "split".

[0168] Here, since there is no need to form a further planarization coating (17), step S5 with respect to the configuration shown in FIG. 1 is omitted. Therefore, the VIA (8) of the graphene film (13) is manufactured here in step S5.

[0169] In step S6, the dielectric coating is first formed on the upper side of the gate electrodes (15a)(15b), preferably resist-planarized on the upper side to achieve the above-mentioned roughness, and then the graphene film (13) is provided on the upper side thereof.

[0170] The trapezoidal shape ensures that the active element, in this case the graphene film (13), follows the particularly inclined edges of the gate electrodes (15a)(15b) or the dielectric coating. As a result, the graphene is always positioned on the dielectric film on the electrodes (15a)(15b) and can be electrostatically controlled particularly well. Also, a particularly uniform electric field can be achieved.

[0171] The steps following the provision of the (respective) graphene film (13) can correspond to the steps of the arrangement shown in FIG. 1 (in particular, the manufacture of the connection element (18), the manufacture of the passivation coating (19), and providing an opening therein).

[0172] FIG. 4 shows an embodiment of a photodetector according to a second aspect of the present invention.

[0173] This embodiment also includes a longitudinal cross-section (12) of the waveguide (11) and an active element (13) including or composed of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical optical signal as a result of the absorption. Also, in the photodetector described in FIG. 3, the active element is exemplarily provided by a graphene film (13).

[0174] Unlike the embodiments of FIGS. 1 and 3, here, the waveguide (11) belonging to the photodetector (3) and its longitudinal cross-section (12) are integrally formed. Specifically, it is a strip waveguide having a rectangular cross-section.

[0175] Furthermore, Supporting the active element (13) two Support elements (20) are arranged on the opposite side of the longitudinal portion of the waveguide (11) and spaced apart therefrom to form two gaps (21), which provides a further difference. Thereby, Support the element (20) is arranged laterally away from the longitudinal cross-section (12) of the waveguide (11). The two gaps (21) do not contain material and are vacuum.

[0176] Support The element (20) can be made of the same material as the longitudinal cross-section (12) of the waveguide (11), but this should be understood illustratively.

[0177] As can be seen from the figure, the active element (13) overlaps, in the lateral direction, the longitudinal cross-section (12) of the waveguide (11), the two gaps (21), and a part of the two Support elements (20).

[0178] Furthermore, in contrast to the embodiments of FIGS. 1 and 3 which include a trapezoidal cross-section, the entire surface of the graphene film (13) is planar.

[0179] As far as the wafer (1), the planarization coating (2) and the passivation coating (19) are concerned, the arrangement of FIG. 4 is the same as that of FIG. 2. As can be seen from the figure, it also does not have a further planarization coating (17). Furthermore, this photodetector (3) does not include a gate electrode.

[0180] To fabricate the arrangement of FIG. 4, steps S1 to S3 may be the same as those described in connection with FIG. 1.

[0181] Next, in step S4, the waveguide (11) and Support the element (20) are manufactured. For this purpose, the waveguide material is deposited on the surface, for example, in the same manner as in the foregoing embodiments, and then, by lithography and etching, the gap (21) is obtained.

[0182] Next, the VIA (8) is manufactured so as to extend through one planarization film (2) and one of each Support element (20) (step S5).

[0183] In step S6, an active element, for example in the form of a graphene film (13), is provided, which is easily performed by a transfer process as described in more detail above.

[0184] The remaining steps may be the same as those according to the provision of the active element (13) in the foregoing embodiments (in particular, the manufacture of the connection element (18), the manufacture of the passivation coating (19), and the provision of the openings therein).

[0185] FIG. 5 shows an embodiment of a modulator (electro - optical modulator) (22) according to a third aspect of the present invention.

[0186] This embodiment also includes, as a longitudinal section (12) of the waveguide (11), four waveguide segments (12a)(12b)(12c)(12d) that extend in the longitudinal direction and extend at least substantially parallel to each other.

[0187] Since it is a modulator (22), it further includes two active elements (13a)(13b) that include or consist of at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or a function of an electric field. In the illustrated example, the two active elements are provided by two graphene films (13a)(13b).

[0188] Of the two active elements (13a) and (13b), the lower element (13a) is disposed on the upper side (10) of the planarization film (2).

[0189] It should be noted that instead of providing and disposing two active elements (13a) and (13b), one active element and one conventional electrode such as made of metal may be provided and disposed corresponding to each other.

[0190] Also, for the four waveguide segments (12a) to (12d), the lower one (12a) of the waveguide segments is disposed between the two active elements (13a) and (13b), and the middle one (12b) of the waveguide segments is disposed above the two active elements (13a) and (13b), particularly above the upper active element (13b). In other words, there is a sandwich configuration (from the lower side to the upper side in FIG. 5) composed of the first active element (13a), the lower waveguide segment (12a), the second active element (13b), and the middle waveguide segment (12b). The upper active element (13b) extends within the longitudinal cross-section (12) of the waveguide. The waveguide segments (12a) to (12d) may all be of the same material.

[0191] The lower and middle waveguide segments (12a) and (12b) function simultaneously as passivation and etching protection. In particular, the lower waveguide segment (12a) is part of the waveguide and protects the lower active element (13a) when the upper active element (13b) is etched. The lower waveguide segment (12a) also functions as an etch stop coat and a passivation coat for protecting the graphene (13a). In particular, the middle waveguide segment (12b) is also an etch stop coat for structuring the upper waveguide segments (12c) and (12d) during the manufacture of the gap (14).

[0192] The remaining two upper waveguide segments (12c) and (12d) are disposed above the intermediate waveguide segment (12b). The two upper waveguide segments (12c) and (12d) are laterally spaced apart from each other, forming a gap (14) extending therebetween. Accordingly, the two upper waveguide segments (12c) and (12d) are positioned adjacent to the upper side of the intermediate waveguide segment (12b), and the gap (14) is located between the two upper waveguide segments (12c) and (12d). This means that exactly one gap (14) is provided above the two active elements (13a) and (13b). The gap (14) is filled with the material of the passivation coating (19).

[0193] The lateral distance between the lower and intermediate waveguide segments (12a) and (12b) exceeds, as can be seen, a multiple of the distance between the two upper waveguide segments (12c) and (12d) in this direction. The cross-sections of the segments (12a) to (12d) are rectangular.

[0194] The two active elements (13a) and (13b) are laterally offset from each other such that they are separated from each other by the lower waveguide segment (12a) and are vertically positioned above and below each other in the overlapping region (23) portion. A portion of one active element (13a) is aligned or overlaps with a portion of the other active element (13b). Specifically, the opposing end regions are vertically positioned or aligned with each other to form the overlapping region (23). As can be seen from FIG. 5, the overlapping region (23) is located below and aligned with the gap (14) formed between the two segments (12c) and (12d).

[0195] The distance of the overlap region (23) is associated with the distance of the lateral gap (14). Specifically, the distance of the overlap region (23) in the lateral direction is about 1.3 times the distance of the gap (14) in this direction. For example, it can also correspond to 1.0 times or 0.8 times, that is, it can have the same or a smaller distance in this direction. In particular, the smaller the overlap, the lower the capacitance and the faster the modulator, resulting in an effect.

[0196] Also, in the case of the modulator (22) having two active elements (13a) (13b), specifically, the active elements (13a) (13b) of the modulator are connected to at least one integrated electronic component (5) from the FEOL (6) of the wafer (1). Each active element (13a) (13b) is associated with a VIA (8) and is connected to the VIA (8) by a contact element (18) in contact therewith. The VIA (8) (the VIA (8) for the active element (13a) on the left side of FIG. 5) penetrates the planarization coating (2), and the VIA (8) (the VIA (8) for the active element (13b) on the right side of FIG. 5) extends through the planarization coating (2) and the waveguide segment (12a), together with the further VIA (8) in the BEOL (7), to ensure the connection.

[0197] As shown in FIGS. 5, 6, and 7, the modulator (22) to be described in more detail can itself be used in a known manner, particularly for optical signal encoding.

[0198] To obtain the arrangement of FIG. 5, steps S1 to S3 can be the same.

[0199] Subsequently, in step S4, the first lower graphene film (13a) can be provided as the lower active element. This can be done in the same manner as described above for one of the active elements (13) of the photodetector (3). Therefore, this can include, for example, the deposition of the entire area of the material and subsequent structuring.

[0200] Next, the connection element (18) belonging to this active element (13a) can be manufactured again in exactly the same manner as the connection elements (18) in FIGS. 1, 3, and 4.

[0201] Next, in step S6, the lower waveguide segment (12a) is manufactured, which can preferably include material deposition and subsequent structuring, similar to the segments (12a)(12b) from the above figures. The same material as in the aforementioned embodiments can be used as the waveguide material.

[0202] In step S7, the second upper graphene film (13b) is provided on the upper side of the segment (12a), preferably in the same manner as the first lower graphene film (13a).

[0203] In step S8, the connection element (18) is manufactured.

[0204] In step S9, the intermediate segment (12b) is preferably manufactured in the same manner as the lower segment (12a), and in step S10, the two upper segments (12c)(12d) are manufactured on the upper side of the intermediate segment (12c). Here too, the waveguide material is deposited in the manner described above and can then be configured to obtain two adjacent segments (12c)(12d) surrounding the gap (14) therebetween. For example, it should be noted that if different waveguide materials are used, it is possible to interrupt or separate the material deposition of the intermediate segment (12b) and the two upper segments (12c)(12d). However, it is not excluded that the material required for the intermediate segment (12b) and the material required for the upper segments (12c)(12d) are applied in one deposition process without interruption, and the segments (12b)(12c)(12d) are obtained by subsequent structuring.

[0205] Step S10 preferably follows step (S11) for obtaining the passivation coating (19) and step (S12) for obtaining the openings therein, as described above in connection with the foregoing drawings. The gap (14) is filled with the material of the passivation coating (19) during or for the deposition of the material for the passivation coating (19).

[0206] FIG. 6 shows an embodiment of a modulator (22) according to a fourth aspect of the present invention.

[0207] This embodiment, in particular, differs from that according to FIG. 5 in that there is a gap (14) below rather than above the active elements (13a)(13b), which is also shown here by way of example by graphene films (13a)(13b). The longitudinal cross-section (12) of the waveguide (11) includes five segments (12a)(12b)(12c)(12d)(12e) instead of four.

[0208] Specifically, two of the lower waveguide segments (12a)(12b) are arranged below the lower active element (13a) and are laterally spaced apart from each other such that a gap (14) is formed therebetween, a first intermediate one (12c) of the waveguide segments is arranged between the two active elements (13a)(13b), a second intermediate waveguide segment (12d) is arranged above the upper one (13b) of the two active elements (13a)(13b), and the upper waveguide segment (12e) is arranged above the second intermediate waveguide segment (12d), in particular in contact with the upper surface. In this example, a sandwich-like structure is formed from the lower side to the upper side, that is, a sandwich-like structure consisting of two lower waveguide segments (12a)(12b), a lower active element (13a), a first intermediate waveguide segment (12c), an upper active element (13b), a second intermediate waveguide segment (12d) and the upper waveguide segment (12e) above it. Here, the two active elements (13a)(13b) extend within the longitudinal cross-section (12) of the waveguide (11).

[0209] Here, the two lower waveguide segments (12a) (12b) and the first intermediate waveguide segment (12c) also function as passivation and etching protection.

[0210] Regarding the lateral extension of the gap (14) in the overlap region (23), it is the same as in FIG. 5.

[0211] To obtain the arrangement of FIG. 6, steps S1 to S3 can be the same again.

[0212] In step S4, the two waveguide segments (12a) (12b) are first fabricated on the upper side (10) of the planarization film (2), and then the waveguide material is preferably deposited in exactly the same manner as in the previous embodiment, whereby a continuous coating is first obtained, and then the gap (14) is preferably subjected to structuring including lithography and etching, especially RIE, and filled with a dielectric material such as SiO 2 The surface is preferably planarized by CMP and / or resist planarization.

[0213] Next, the VIA (8) associated with the graphene film (13a) on the left side of FIG. 5 can be fabricated (step S5), which can be done by extending the VIA (8) through the planarization film (2) of FIG. 5 and one of the left segments of the lower segment (12a) as described above.

[0214] Next, the lower graphene film (13a) is provided (step S6). This can be done in the same manner as in the previous embodiment. The lower graphene film (13a) is preferably arranged to completely overlap the gap (14) laterally as shown in FIG. 5.

[0215] Next, the associated connection element (18) is manufactured as described above (step S6), and then the VIA (8) for the first intermediate waveguide segment (12c) and the upper graphene film (13b) (step S7), the upper graphene film (13b) (S8), the first waveguide segment (12d) (S9), and the upper segment (12e) (S10) can be manufactured. The manufacture of these waveguide segments (12c)(12d)(12e) is carried out, for example, in the same manner as the manufacture of the segments (12a)-(12d) of FIG. 5, except that the segment (12e) is not provided with a gap and is etched only as a strip-shaped segment having a rectangular cross-section.

[0216] Finally, the above-described steps for obtaining the passivation coating (19) (S11) and the opening (S12) therein can also be carried out here.

[0217] FIG. 7 shows an embodiment of a modulator (22) according to a fifth aspect of the present invention.

[0218] This embodiment differs only in that, compared with the example of FIG. 6, a second gap (14) is additionally provided here, by way of example, above the two active elements (13a)(13b) formed by the graphene film. Instead of the strip-shaped waveguide segment (12e) as in FIG. 6, two adjacent segments (12e) and (12f) spaced apart from each other to form the second gap (upper gap) (14) are provided above the upper graphene film (13b) in contact with the upper side of the second intermediate segment (12d). It should be noted that the upper gap (14) is also filled with the material of the passivation coating (19) in this case during or for the deposition of the material of the passivation coating (19).

[0219] In this embodiment, a sandwich structure includes two lower waveguide segments (12a) and (12b) extending from the lower side to the upper side, a lower active element (13a), a first intermediate waveguide segment (12c), an upper active element (13b), a second intermediate waveguide segment (12d), and two upper waveguide segments (12e) and (12f) above it. Here too, the two active elements (13a) and (13b) extend within the longitudinal cross-section (12) of the waveguide (11).

[0220] The two lower waveguide segments (12a) and (12b) and the first intermediate waveguide segment (12c) also function here as passivation and etching protection simultaneously.

[0221] As shown in FIG. 6, the overlap region (23) formed by the two active elements (13a) and (13b) due to the offset is located above the lower gap (14) between the lower segments (12a) and (12b), and is also located above the upper gap (14) between the upper segments (12e) and (12f).

[0222] The lower gap (14), the overlap region (23), and the upper gap (14) are aligned.

[0223] Furthermore, here, the distance of the overlap region (23) and the distances of both gaps (14) are related to each other laterally. Specifically, the lateral distance of the overlap region (23) is about 1.3 times the distances of the upper gap (14) and the lower gap (14). This magnification may be, for example, 1.0 times or 0.8 times.

[0224] To obtain the arrangement of FIG. 7, the same procedure as that of FIG. 6 can be followed except for the only difference that the upper gap (14) also has to be etched. As a result, instead of one upper segment (12e), two upper segments (12e) and (12f) having a gap (14) are obtained above the second middle waveguide segment (12d).

[0225] As described above, examples of semiconductor devices according to the present invention each include a plurality of photodetectors (3) or modulators (22), only one of which is shown as a partial cross-section as an example. In the illustrated embodiments of the semiconductor devices according to the present invention, all the photodetectors (3) or modulators (22) can be identical in design. And this compatibility particularly enables simple and rapid manufacturing. However, of course, it should be emphasized that the semiconductor devices according to the present invention can also include different embodiments of the photodetectors (3) and / or modulators (22) shown in FIGS. 1 and 3 to 6, for example, the photodetector (3) according to FIG. 1 and the modulator according to FIG. 5. Also, two or more different embodiments, for example, one or more of each of the shown photodetectors (3) and / or modulators (22) may be present.

[0226] Note that each configuration provided on the wafer (1) including the planarization film (2) (which may include the films shown by (17) and (19)) and the photodetector (3) and / or modulator (22) can be designed as a photonic platform respectively. Further, note that it is also possible in principle to bond a separately manufactured configuration to the wafer (1) instead of the photonic platform manufactured on the BEOL (7) of the wafer (1) as in the above-described embodiments.

[0227] After completion of the semiconductor device according to the present invention, a plurality of semiconductor devices each formed by a chip with integrated photonics having one or more photodetectors (3) and / or modulators (22) according to the present invention can be obtained simply and quickly by merely dicing, that is, dividing.

[0228] The "bare chips" provided with the photodetectors (3) and / or modulators (22) obtained by dicing are inserted into packages and supplied for further use, as is also known from conventional bare chips.

[0229] A chip obtained by dicing a semiconductor device having one or more of a wafer (1) and a photodetector (3) and / or a modulator (22) is an embodiment of the semiconductor device according to the present invention.

[0230] In the figures showing the embodiments, it should be noted that all partial cross-sectional views show only relatively small cross-sections, specifically, a cross-section showing only a small portion of the wafer (1), or a cross-section showing a chip obtained after dicing. Therefore, all parts represent both parts through the embodiments of the semiconductor device according to the present invention and through the embodiments of the semiconductor device according to the present invention. Furthermore, it should be noted that a plurality of photodetectors (3) and / or modulators (22), for example, dozens, hundreds, or thousands, can be provided on a single chip depending on the application.

Claims

1. A longitudinal cross-section (12) of a waveguide (11) comprising or formed by at least two longitudinally extending waveguide segments (12a)(12b) that are substantially parallel to each other, and an active element (13) that overlaps the longitudinal cross-section (12) of the waveguide (11), includes or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electro-optical signal as a result of the absorption, and the two waveguide segments (12a)(12b) are spaced apart from each other so as to form a gap (14) extending therebetween, and the two waveguide segments (12a)(12b) are each in contact with at least two gate electrodes (15a)(15b) at least partially on at least one side, a photodetector (3).

2. The photodetector (3) according to claim 1, characterized in that the two waveguide segments (12a)(12b) are laterally spaced apart from each other.

3. The photodetector (3) according to claim 1 or 2, characterized in that the two waveguide segments (12a)(12b) are each in contact with the at least two gate electrodes (15a)(15b) at least partially on the side facing the active element (13).

4. The photodetector (3) according to any one of claims 1 to 3, characterized in that the two gate electrodes (15a)(15b) contain or consist of silicon.

5. The photodetector (3) according to any one of claims 1 to 4, characterized in that each of the two gate electrodes (15a)(15b) is in contact with the upper surface of the two waveguide segments (12a)(12b) on its lower side and with the lower surface of a dielectric film provided between the active element (13) and the two waveguide segments (12a)(12b) on its upper side.

6. The photodetector (3) according to any one of claims 1 to 5, characterized in that the two gate electrodes (15a)(15b) contain or consist of a material that is transparent to electromagnetic radiation of at least one wavelength and / or a conductive material.

7. Each of the two gate electrodes (15a) and (15b) is associated with a connection element (8) in contact therewith, and one of the connection elements (8) extends through one of the two waveguide segments (12a) and (12b). The photodetector (3) according to any one of claims 1 to 6, characterized in that.

8. The active element (13) overlaps with the two waveguide segments (12a) and (12b) and at least a part of the gap (14) therebetween. The photodetector (3) according to any one of claims 1 to 7, characterized in that.

9. A longitudinal cross-section (12) of a waveguide (11) and an active element (13) including or consisting of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electro-optical signal as a result of the absorption. On both sides of the longitudinal cross-section (12) of the waveguide (11), two support elements (20) are arranged at intervals so as to form two gaps (21). The two gaps (21) do not contain a material. The active element (13) overlaps at least a part of the longitudinal cross-section (12) of the waveguide (11), the two gaps (21) and the two support elements (20). A photodetector (3), characterized in that.

10. The active element (13) is located above the longitudinal cross-section (12) of the waveguide (11) facing the active element (13) and / or above the support element (20) facing the active element (13). The photodetector (3) according to claim 9, characterized in that.

11. At least one material of the active element (13) is graphene and / or at least one dichalcogenide and / or a heterostructure of two-dimensional materials and / or germanium and / or at least one electro-optical polymer and / or silicon and / or at least one compound semiconductor. The photodetector according to any one of claims 1 to 10, characterized in that.

12. A longitudinal cross-section (12) of a waveguide (11) including or formed by four longitudinally extending waveguide segments (12a), (12b), (12c), (12d) that are at least substantially parallel to each other. Two active elements (13a) (13b) comprising or consisting of at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or such one active element and one electrode, One (12a) below the waveguide segment is arranged between the two active elements (13a) (13b) or between the one active element and the one electrode, one (12b) in the middle between the upper and lower sides of the waveguide segment is arranged above the two active elements (13a) (13b) or above the one active element and the one electrode, and the remaining two upper ones (12c) (12d) of the waveguide segment are arranged above one (12b) in the middle between the upper and lower sides of the waveguide segment, and the remaining two upper ones (12c) (12d) of the waveguide segment are spaced apart from each other so as to form a gap (14) extending therebetween, a modulator (22) characterized by this.

13. The longitudinal cross-section (12) of a waveguide (11) comprising or formed by at least five longitudinally extending waveguide segments (12a) (12b) (12c) (12d) (12e) that are at least substantially parallel to each other, Two active elements (13a) (13b) comprising or consisting of at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or such one active element and one electrode, Two (12a) and (12b) on the lower side of the waveguide segment are arranged below the two active elements (13a) and (13b) or below the one active element and the one electrode, and are spaced apart from each other to form a gap (14) extending therebetween. One (12c) in the middle between the upper and lower sides of the waveguide segment is arranged between the two active elements (13a) and (13b) or between the one active element and the one electrode. The other one (12d) in the middle between the upper and lower sides of the waveguide segment is arranged above the two active elements (13a) and (13b) or above the one active element and the one electrode. One (12e) on the upper side of the waveguide segment is arranged above the other one (12d) in the middle between the upper and lower sides of the waveguide segment. A modulator (22) characterized by this.

14. A longitudinal cross-section (12) of a waveguide (11) including or formed by at least six longitudinally extending waveguide segments (12a), (12b), (12c), (12d), (12e), (12f) that are substantially parallel to each other, Two active elements (13a) and (13b) including or consisting of at least one material whose refractive index changes as a function of voltage and / or the presence of charge and / or an electric field, or such one active element and one electrode, Two (12a) and (12b) on the lower side of the waveguide segment are arranged below the two active elements (13a) and (13b) or below the one active element and the one electrode, and are spaced apart from each other so as to form a gap (14) extending therebetween. One (12c) in the middle between the upper and lower sides of the waveguide segment is arranged between the two active elements (13a) and (13b) or between the one active element and the one electrode. The other one (12d) in the middle between the upper and lower sides of the waveguide segment is arranged above the two active elements (13a) and (13b) or above the one active element and the one electrode. The remaining two (12e) and (12f) on the upper side of the waveguide segment are arranged above the other one (12d) in the middle between the upper and lower sides of the waveguide segment, and are spaced apart from each other so as to form a gap (14) extending therebetween. A modulator (22) characterized by this.

15. The modulator (22) according to any one of claims 12 to 14, characterized in that the two active elements (13a) and (13b) are spaced apart from each other and arranged to offset each other so that one of the two active elements (13a) and (13b) is partially located above the other to form an overlap region (23).

16. The modulator (22) according to claim 15, characterized in that the overlap region (23) is located above or below the gap (14).

17. The modulator (22) according to claim 15 or 16, characterized in that the overlap region (23) is located above one gap (14) and below the other gap (14).

18. The modulator (22) according to any one of claims 15 to 17, characterized in that the lateral distance of the overlap region (23) is in the range of 0.8 to 1.8 times the lateral distance of at least one of the gaps (14).

19. Exactly one gap (14) formed between two said waveguide segments (12a to 12f) spaced apart from each other is provided above and / or below said two active elements (13a)(13b) or said one active element and said one electrode, the modulator (22) according to any one of claims 12 to 18.

20. At least one material of said active elements (13a)(13b) is graphene and / or at least one dichalcogenide and / or a heterostructure of two-dimensional materials and / or germanium and / or at least one electro-optic polymer and / or silicon and / or at least one compound semiconductor, the modulator (22) according to any one of claims 12 to 19.

21. The longitudinal cross-section (12) of said waveguide (11) is arranged in contact or non-contact on a planarization coating (2)(17), the roughness of the planarization coating (2)(17) on the side where the longitudinal cross-section (12) of said waveguide (11) is arranged is at least partially characterized by a range from 1.0 nm RMS to 0.1 nm RMS, and / or The longitudinal cross-section (12) of said waveguide (11) is at least partially embedded in the planarization coating (2)(17) where one or one of said active elements (13)(13a)(13b) is arranged, the roughness of the planarization coating (2)(17) on the side where the active element (13)(13a)(13b) is arranged is at least partially characterized by a range from 1.0 nm RMS to 0.1 nm RMS, the photodetector (3) according to any one of claims 1 to 11.

22. The longitudinal cross-section (12) of the waveguide (11) comprises or consists of titanium dioxide and / or aluminum nitride and / or tantalum pentoxide and / or silicon nitride and / or aluminum oxide and / or silicon oxynitride and / or lithium niobate and / or silicon and / or indium phosphate and / or gallium arsenide and / or indium gallium arsenide and / or aluminum gallium arsenide and / or at least one dichalcogenide and / or chalcogenide glass and / or a heterostructure of two-dimensional materials and / or a resin or resin-containing material and / or a polymer or polymer-containing material, the photodetector (3) according to any one of claims 1 to 11.

23. The longitudinal cross-section (12) of the waveguide (11) is arranged in contact or non-contact on the planarizing film (2)(17), and the roughness of the planarizing film (2)(17) on the side where the longitudinal cross-section (12) of the waveguide (11) is arranged is at least partially characterized by a range from 1.0 nm RMS to 0.1 nm RMS, and / or, The longitudinal cross-section (12) of the waveguide (11) is at least partially embedded in the planarizing film (2)(17) where one or one of the active elements (13)(13a)(13b) is arranged, and the roughness of the planarizing film (2)(17) on the side where the active element (13)(13a)(13b) is arranged is at least partially characterized by a range from 1.0 nm RMS to 0.1 nm RMS, the modulator (22) according to any one of claims 12 to 20.

24. The longitudinal cross-section (12) of the waveguide (11) comprises or consists of titanium dioxide and / or aluminum nitride and / or tantalum pentoxide and / or silicon nitride and / or aluminum oxide and / or silicon oxynitride and / or lithium niobate and / or silicon and / or indium phosphate and / or gallium arsenide and / or indium gallium arsenide and / or aluminum gallium arsenide and / or at least one dichalcogenide and / or chalcogenide glass and / or a heterostructure of two-dimensional materials and / or a resin or resin-containing material and / or a polymer or polymer-containing material. The modulator (22) according to any one of claims 12 to 20, characterized in that it comprises or consists of the above materials.

25. A semiconductor device, comprising a chip and at least one photodetector (3) and / or modulator (22) according to any one of claims 1 to 24.

26. The semiconductor device according to claim 25, characterized in that the photodetector (3) and / or the modulator (22) is part of a photonic platform manufactured or bonded onto the chip.

27. A semiconductor device, comprising a wafer (1) and at least one photodetector (3) and / or modulator (22) according to any one of claims 1 to 24.

28. The semiconductor device according to claim 27, characterized in that the photodetector (3) and / or the modulator (22) is part of a photonic platform manufactured or bonded onto the wafer (1).

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