EP4118486A1

EP4118486A1 - Photodetector, modulator, semiconductor device and semiconductor apparatus

Info

Publication number: EP4118486A1
Application number: EP21709626.2A
Authority: EP
Inventors: Daniel SCHALL
Original assignee: Amo GmbH
Current assignee: Black Semiconductor GmbH
Priority date: 2020-03-09
Filing date: 2021-02-23
Publication date: 2023-01-18
Also published as: DE202020101285U1; WO2021180464A1; US20230327043A1; CA3174453A1; KR20220151615A; JP2023517900A; CN115280228A

Abstract

The present invention relates to a photodetector (3) comprising: a longitudinal portion (12) of a waveguide (11) which comprises or is formed by two waveguide segments (12a, 12b), which extend at least substantially parallel to one another in the longitudinal direction and are preferably distanced from one another in the transverse direction, forming a gap (14) between them; and an active element (13), which overlies the longitudinal portion (12) of the waveguide and comprises at least one material or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electric photosignal as a result of the absorption, the two waveguide segments (12a, 12b) each being in contact, at least in some portions, on at least one side, in particular on the side facing the active element (14), with a gate electrode (15a, 15b) which preferably comprises silicon or consists of silicon.

Description

description

Photodetector, modulator, semiconductor device and semiconductor device The invention relates to a photodetector and a modulator. In addition, the invention relates to a semiconductor device with a chip and at least one photodetector and / or modulator and a semiconductor device with a wafer and at least one photodetector and / or modulator.

Electro-optical devices, for example photodetectors or electro-optical modulators, are known from the prior art which have a waveguide or longitudinal section of such a waveguide with several waveguide segments extending in the longitudinal direction and at least substantially parallel to one another and - in the case of a photodetector - one or - in the case of an electro-optical modulator - two films of graph comprise as active elements. Such are disclosed, for example, in US Pat. No. 9,893,219 B2. The known photodetectors and modulators have in principle been proven. However, there is a need for further, alternatively designed photodetectors and modulators, which can be manufactured with reasonable effort and are characterized by an optimal mode of operation. It is therefore an object of the present invention to specify alternatively designed photodetectors and modulators which meet these requirements. This object is achieved with respect to a photodetector with the measures mentioned in claims 1 and 6 and with respect to a modulator with the measures mentioned in claims 9, 10 and 11. According to a first aspect of the invention, a photodetector is provided which comprises a longitudinal section of a waveguide comprising two waveguide segments extending in the longitudinal direction and at least substantially parallel to one another, which are spaced apart from one another in particular in the transverse direction to form a gap extending between them or is formed thereby, and an active element which overlaps the longitudinal section of the waveguide and comprises at least one material or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption, the two waveguide segments - elements are in each case in contact on at least one side, in particular on the side facing the active element, at least in sections with a gate electrode preferably comprising silicon or consisting of silicon. A method according to the invention for producing such a detector comprises, for example, that a waveguide material is applied, preferably deposited, in particular to a wafer or a layer provided on or above a wafer, and a gate electrode material, preferably silicon, is applied, in particular deposited, and a structuring takes place in order to obtain the two waveguide segments with the gap between them and the gate electrodes, and the active element is provided. A pn junction can be implemented in the active element during operation by means of the gate electrodes. By arranging the pn junction in the optical mode Be rich, an optimal overlap between the absorbing material and the active area of the photodetector is achieved. In an advantageous embodiment, it is provided that the gate electrodes each on their underside with the top side of a waveguide segment and with their top side with the bottom side of a dielectric layer provided between the active element and the waveguide segments, which expediently comprises at least one dielectric material or at least a dielectric material, are in contact. Silicon dioxide (S1O2) and aluminum oxide (AL2O3), for example, have proven to be suitable materials. As an alternative to the term dielectric material, the term dielectric is also used. The dielectric layer can also be referred to as a gate dielectric.

In a further development, the active element can be or will be arranged on the top side of the dielectric layer. It can have been or will be produced on it. In a preferred embodiment, the dielectric layer can have a roughness in the range from 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, on its upper side , 1 nm RMS. The abbreviation RMS stands for root mean squared. The RMS roughness is also referred to as square roughness in German. A top side with a roughness in this area has proven to be particularly suitable in particular in the case that the active element is provided on the top side of the dielectric layer, in particular is produced thereon. The thickness of the dielectric layer can be, for example, in the range from 10 to 20 nm.

The gate electrodes preferably comprise or consist of a material that is transparent and / or electrically conductive for electromagnetic radiation of at least one wavelength, preferably at least one wavelength range.

The gate electrodes further preferably comprise at least one material that is transparent to electromagnetic radiation with a wavelength of 850 nm and / or 1310 nm and / or 1550 nm or consists of such a material. It is particularly preferred for electromagnetic radiation in the wavelength range from 800 nm to 900 nm and / or from 1260 nm to 1360 nm (so-called original tape or O-band for short) and / or 1360 nm to 1460 nm (so-called extend band or short E-band) and / or 1460 nm to 1530 nm (so-called short band or short S-band) and / or from 1530 nm to 1565 nm (so-called conventional band or short C-band) and / or 1565 nm to 1625 nm (so-called long band or L-band for short) transparent. These tapes are already known from the field of communications engineering.

Accordingly, this preferably applies to the gate electrode material that is used in the context of the production method.

Sili has proven to be a particularly suitable material for the gate electrodes. It can be polysilicon. Indium tin oxide (ITO) can also be used. The material or the materials from which the gate electrodes consist or are produced can also be doped.

The respective gate electrode can, for example, be on the side of the respective waveguide segment of the world facing the active element A layer provided in the longitudinal section of the waveguide may be, particularly preferably a layer which is or has been produced on the respective waveguide segment.

In addition, it can be provided that the gate electrodes are deposited by deposition, in particular chemical vapor deposition (CVD), preferably low pressure chemical vapor deposition (LPCVD) and / or plasma-assisted chemical vapor deposition dung (English: plasma enhanced chemical vapor deposition, short: PECVD), and / or by physical vapor deposition (English: physical vapor deposition, short: PVD) of a coating material have been or are being produced.

There are different methods of chemical vapor deposition known from the prior art, all of which have been or can be used within the scope of the present invention. What they all have in common is, as a rule, a chemical reaction between the gases introduced, which leads to the deposition of the desired material.

With regard to the physical vapor deposition, it is also true that all variants known from the prior art have been or can be used. A purely exemplary example is electron beam evaporation, in which material is melted and vaporized by means of an electron beam, as well as thermal evaporation, in which material is heated to the melting point by means of a heater and evaporated onto a target substrate, and cathode sputtering. ter deposition), in which atoms are knocked out of a material carrier by means of a plasma and deposited on a target substrate. As an alternative or in addition to the aforementioned deposition methods, atomic layer deposition (ALD for short) can also be used in order to obtain the respective gate electrode. As part of this, insulating or conductive materials (dielectrics, semiconductors or metals) are sequentially deposited atomic layer by atomic layer. A transfer procedure can also be used or may have been used.

In a further development, it can also be provided that each of the two gate electrodes is assigned a connecting element that is in contact therewith, and one of the connecting elements preferably extends through one of the waveguide segments. A suitable structuring process can follow or have followed the deposition, which can include lithography and / or etching, for example. The connecting elements are preferably vertical electrical connections, which are also referred to in English as Vertical Interconnect Access, or via or VIA for short. VIAs are generally defined by lithography and, in particular, are dry chemically etched using reactive ion etching (RIE for short). Thereafter, metallization is preferred and the metallized surface is structured by means of CMP (Damascene process) or by means of lithography and RIE.

Reactive ion etching is a dry etching process in which, as a rule, specific gaseous chemicals that are excited to form a plasma enable selective and directional etching of a substrate surface. A lacquer mask can protect parts that are not to be etched. The etching chemistry and the parameters of the process usually determine the selectivity of the process, i.e. the etching rates of different materials. This property is crucial in order to limit the depth of an etching process and thus to define layers separately from one another. The connecting elements expediently comprise or consist of at least one electrically conductive material, in particular metal, such as copper and / or aluminum and / or tungsten.

In a further advantageous embodiment it is also provided that the active element overlaps the two waveguide segments and the gap between them at least in sections, in particular in the transverse direction. The transverse direction is expediently to be understood as the direction oriented orthogonally to the longitudinal direction of the longitudinal section of the waveguide.

According to a second aspect of the invention, a photodetector is provided which comprises a longitudinal section of a waveguide and an active element which comprises at least one material or consists of at least one material which absorbs electromagnetic radiation of at least one wavelength and as a result of the absorption a Generated electrical photo signal, two support elements on opposite sides of the longitudinal section of the waveguide to form two gaps of this are arranged spaced apart, the two gaps are free of material, and the active element the longitudinal section of the waveguide and the two gaps and overlaps at least sections of the two support elements, in particular in the transverse direction. The two support elements are preferably arranged at a distance from the longitudinal section in the transverse direction.

A method according to the invention for producing such a detector comprises, for example, that a waveguide material is applied, preferably deposited, in particular to a wafer or a layer provided on or above a wafer, and structuring is carried out in order to create the two gaps and the longitudinal section of the waveguide and the To obtain support elements, and the active element above the longitudinal section of the waveguide and the support elements is provided.

The gaps that are free of material are given in particular by areas from which material was removed by an etching process and no new material was subsequently provided, for example deposited. They can be filled with air or another gas, or they can be under vacuum. However, there is no solid material in them. A vacuum is preferably to be understood as a space evacuated, for example, by pumping out.

In a preferred embodiment, the active element rests on the top side of the longitudinal section of the waveguide facing it and / or on the top sides of the support elements facing it.

The support elements can consist of the same material as the longitudinal section of the waveguide, this being understood as an example. For example, T1O2 and / or Si have proven to be suitable materials for the support elements. All other materials that are suitable for waveguides can also be used.

It may be that the active element comprises at least one material or consists of at least one material that can absorb electromagnetic radiation with a wavelength of 850 nm and / or 1310 nm and / or 1550 nm and generate a photo signal as a result of the absorption. It is particularly preferred that there is electromagnetic radiation in the wavelength range from 800 nm to 900 nm and / or from 1260 nm to 1360 nm (so-called original tape or O-band for short) and / or 1360 nm to 1460 nm (so-called extended band or short E-band) and / or 1460 nm to 1530 nm (so-called short band or short S-band) and / or from 1530 nm to 1565 nm (so-called conventional band or C-band for short) and / or 1565 nm to 1625 nm (so-called long band or L-band for short) and can generate a photo signal as a result of the absorption. It has proven to be particularly suitable if the at least one material of the active element that absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption is graphene and / or at least one dichalcogenide, in particular two-dimensional Transition metal dichalcogenide and / or heterostructures made from 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 is.

In particular, a photodetector can be used to convert signals back from the optical to the electronic world.

According to a third aspect of the invention, an in particular electro-optical modulator is provided which comprises a longitudinal section of a waveguide which comprises or is formed by four waveguide segments extending in the longitudinal direction and at least substantially parallel to one another, and two active elements, comprise at least one material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, or comprises such an active element and an electrode, wherein a lower one of the waveguide segments is arranged between the two active elements or between the active element and the electrode, a middle one of the waveguide segments above the two active elements or above of the active element and the electrode is arranged, and the two remaining, upper waveguide segments are arranged above the middle waveguide tersegmentes, the two upper waveguide segments are preferably spaced apart in the transverse direction to form a gap extending between them, includes.

Then in particular a sandwich-like structure can be present, which - from bottom to top - an active element or the electrode, then the lower waveguide segment of the longitudinal section of the waveguide, then the second active element or the electrode, then the middle waveguide segment of the longitudinal section of the waveguide and then comprises the two upper segments of the longitudinal section of the waveguide.

A method according to the invention for producing such a modulator comprises, for example, that an active element or an electrode is provided in particular on a wafer or on a layer provided on or above a wafer, and a waveguide material is applied, preferably deposited, around the lower waveguide segment and the further active element or an electrode is provided above the lower waveguide segment, and a waveguide material is applied, preferably deposited, in order to obtain the middle waveguide segment, and a waveguide material is applied, preferably deposited, and a subsequent structuring takes place, to get the two upper waveguide segments and the gap between them.

That an element or segment or a layer is arranged above or below another element or segment or another layer (in other words that it is arranged above or below another element or segment or another layer) includes both that it is located directly on or directly below the other element or segment or also the other layer, and with this or this, for example with the top or bottom of the other element or segment or the other layer in There is contact, i.e. touching it, or that at least one further element or segment or at least one further layer (above or below) lies in between. This applies to the photodetectors and modulators according to all aspects of the invention. According to a fourth aspect of the invention, an in particular electro-optical modulator is provided comprising a longitudinal section of a waveguide which comprises or is formed by four waveguide segments extending in the longitudinal direction and at least substantially parallel to one another, and two active elements, the least comprise a material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, or such an active element and an electrode, with two lower ones of the waveguide segments below the active elements or arranged below the active element and the electrode and preferably spaced apart from one another in the transverse direction with the formation of a gap extending between them, and a first middle of the waveguide segments between the two active elements or between the active element and the electr or is arranged, and a second central waveguide segment is arranged above the two active elements or above the active element and the electrode, and an upper waveguide segment is arranged above the second central waveguide segment.

The upper waveguide segment preferably has an extension in the transverse direction which corresponds to the extension of the further waveguide segments Transverse direction falls below. It may be that the extension of the two lower and the two middle segments in the transverse direction is a multiple of the extension of the upper segment in this direction.

A method according to the invention for producing such a modulator comprises, for example, that a waveguide material is applied, preferably deposited, in particular to a wafer or on a layer provided on or above a wafer, and structuring takes place in order to obtain the two lower waveguide segments and the gap between them and above this an active element or an electrode is provided, and a waveguide material is applied, preferably deposited, in order to obtain the first central waveguide segment, and the further active element or an electrode is provided above the first central waveguide segment, and a waveguide material applied, is preferably deposited in order to obtain the second middle Wel lenleitersegment, and applied a waveguide material, is preferably deposited and preferably a subsequent structuring is carried out to the upper waveguide segment z u received.

According to a fifth aspect of the invention, an in particular electro-optical modulator is provided comprising a longitudinal section of a waveguide which comprises or is formed by six waveguide segments extending in the longitudinal direction and at least substantially parallel to one another, and two active elements, the least comprise a material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, or such an active element and an electrode, two lower ones of the waveguide segments below the active elements or arranged beneath the active element and the electrode and preferably in the transverse direction to form a itself between them extending gap are spaced apart, and a first central waveguide segments between the two active elements or between the active element and the electrode is angeord net, and a second central waveguide segment is arranged above the two active elements or above the active element and the electrode is, and the two remaining, upper waveguide segments are arranged above the second central waveguide segment, where the two upper waveguide segments are preferably spaced apart in the transverse direction with the formation of a gap extending between them.

A method according to the invention for producing such a modulator comprises, for example, that a waveguide material is applied, preferably deposited, in particular to a wafer or on a layer provided on or above a wafer, and structuring takes place in order to obtain the two lower waveguide segments and the gap between them and above this an active element or an electrode is provided, and a waveguide material is applied, preferably deposited, in order to obtain the first central waveguide segment, and the further active element or an electrode is provided above the first central waveguide segment, and a waveguide material applied, is preferably deposited in order to obtain the second middle waveguide segment, and a waveguide material is applied, is preferably deposited and a subsequent structuring takes place around the two upper waveguide segments and to keep the gap in between.

An electro-optical modulator can be used in particular for optical signal coding. An electro-optical modulator can also be designed as a ring modulator. In the case of a modulator that comprises two active elements, it is also preferred that the two active elements are or will be arranged at a distance from one another and offset from one another in such a way that they lie on top of one another in sections in an overlapping area. If a modulator comprises only one active element and one (conventional) electrode, it can analogously apply in a preferred embodiment that the active element and the electrode are or will be spaced apart from one another and offset from one another in such a way that they are partially above one another in an overlapping area lie.

In other words, a section of the one active element then aligns or overlaps with a section of the other active element or the electrode, expediently without these touching one another. Preferably, at least in the area of superposition, in other words in the overlapping area, the two active elements or the active element and the electrode or at least sections of these extend at least substantially parallel to one another. The overlap area is particularly preferably above or below the gap or is provided there. He especially curses with this one. The optical mode can then be guided in the slot between the two waveguide segments with a high electric field strength (slot mode). At the edge areas above and below the slot, part of the optical mode is located outside the slot. In these areas, the optical mode can interact particularly efficiently with an active optical material.

If there are two gaps, it is particularly important that the overlap area is above one and below the other gap. is seen. The two gaps and the overlap area or a section of this can be aligned, which has proven to be particularly suitable. Due to the two superposed gaps, a particularly high proportion of the optical mode is located in the area between the gaps, in particular in comparison to an arrangement with only one gap, which enables a particularly efficient interaction with an electro-optical material.

In a further development, exactly one gap formed between two spaced-apart waveguide segments is or will be provided above the two active elements or above the active element and the electrode. As an alternative or in addition, exactly one gap formed between two spaced-apart waveguide segments can be provided below the two active elements or below the active element and the electrode.

The extent of the overlap area in the transverse direction corresponds in a further particularly advantageous embodiment in the range from 0.8 to 1.8 times, preferably 1.0 to 1.5 times the extent of the or at least one of the gaps in the transverse direction.

The fact that a material changes its refractive index is to be understood in particular to mean that it changes its dispersion (in particular refractive index) and / or its absorption. The dispersion or refractive index is usually given by the real part and the absorption by the imaginary part of the complex refractive index. Materials whose refractive index changes as a function of a voltage and / or the presence of charge (s) and / or an electric field are to be understood in the present case in particular as those that result from the Pockels effect and / or the Franz-Keldysh -Effect and / or the Kerr effect. Furthermore Materials that are characterized by the plasma dispersion effect are also considered as such materials in the present case.

It has proven to be particularly suitable if the at least one material is at least one of the active elements whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, graphene, optionally chemically modified graphene and / or at least one dichalcogenide, in particular two-dimensional transition metal dichalcogenide, and / or heterostructures made of two-dimensional materials and / or germanium and / or lithium niobate 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, is.

Graphene has proven to be a particularly suitable material for the active element or elements for all five aspects of the invention.

Electro-optical polymers are to be understood in particular as polymers which are distinguished by the fact that they have a strong linear electro-optical coefficient (Pockels effect). A strong linear electro-optical coefficient is preferably to be understood as one which is at least 150 pm / V, preferably at least 250 pm / V. Then the electro-optical coefficient is at least about five times that of lithium niobath.

There are different chalcogenides. In the context of the present invention, transition metal dichalcogenides in particular have proven to be particularly suitable as two-dimensional materials, such as MoS2 or WSe2. It should be noted that lithium niobate and electro-optical polymers are based on the electro-optical, in particular the Pockels effect, ie the E field changes the refractive index (such as, for example, the Pockels effect is used in the Pockels cell). In the case of germanium, it is the Franz Keldysh effect, ie the field shifts the valence and conduction band edges against each other, so that the optical properties change. 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 range of the optical mode (either there is a capacitor in the arrangement, which is charged, or a diode with a barrier layer, which depletes and is enriched). The refractive index (real part of the index) and the absorption (imaginary part of the index, leads to free carrier absorption) change with the charge carrier concentration.

III-V semiconductors or, in a manner known per se, are compound semiconductors that consist of elements from main group III and V best. II-VI semiconductors or, in a manner known per se, are compound semiconductors which consist of elements of main group II or group 12 elements and elements of main group VI.

Many materials are characterized both by the fact that their refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, as well as by the fact that they absorb electromagnetic radiation of at least one wavelength and, as a result of the absorption, an electrical photo signal produce. This is the case for graphs, for example. Accordingly, graphene is suitable for both the active elements of photodetectors and modulators. This also applies to dichalcogenides, such as two-dimensional transition metal dichalcogenides, heterostructures made from two-dimensional materials, Germanium, silicon and compound semiconductors, in particular III-V semiconductors and / or II-VI semiconductors. Lithium niobath, for example, is usually only suitable for modulators. Since it is transparent, it does not have the absorbing property and is therefore out of the question for photodetectors.

In the case of a material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption and / or whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, one can also use an electro - speak optically active material. In other words, the active element or the active elements comprise at least one electro-optically active material or, in other words, consist of at least one electro-optically active material.

It may be that the or at least one of the active elements is present or is provided in the form of a film. A film is preferably characterized in a manner known per se by a significantly greater lateral extent than its thickness. The at least one active element can also be characterized by a square or rectangular cross section.

The or at least one active element can further comprise one or more layers or layers made of at least one material whose refractive index changes and / or which absorbs, or can be formed from one or more layers or layers of at least one such material. In particular, it can be provided that the or at least one active element is designed as a film which comprises a plurality of layers or layers made of one or also different materials. Films made of graphene, possibly chemically modified graphene, or dichalcogenide-graphene heterostructures consisting of at least one layer of graphene and at least one layer of a dichalcogenide or arrangements of at least one layer of boron tride and at least one layer of graphene have proven to be particularly suitable proven.

Active elements can, for example, also comprise or be given by one or more silicon layers. In this case, in particular, it can be provided that one or more active elements or sections thereof form a waveguide (section).

The active element or elements can furthermore be doped or have doped sections or regions, for example p-doped and / or n-doped or comprise corresponding sections or regions. It can also be that a p-doped and an n-doped region and an undoped region preferably lying in between are present or are provided. This is also known as the pin junction, where the i stands for intrinsic, i.e. undoped. In the context of the production of the respective active element or elements, the same methods can be used or have been used that were explained above in connection with the gate electrodes.

These also include transfer procedures. This then means in particular that the element or the respective element is / are or was / were not produced monolithically, for example, on one layer, but produced separately and then transferred, in other words, is / are / was / was / were transferred . A transfer method for graphene is, for example, from the articles “Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils” by Li et al., Science 324, 1312, (2009) and “ Roll-to-roll production of 30-inch graphene films for transparent electrodes ”by Bae et al, Nature Nanotech 5, 574-578 (2010) or for LiNbO from the article“ Integrated lithium niobate electro-optic modulators operating at CMOS- compatible voltages ”, Nature volume 562, pages 101104 (2018) or, inter alia, for GaAs from the article“ Transfer print techniques for heterogeneous integration of photonic components ”, Progress in Quantum Electronics Volume 52, March 2017, Pages 1-17. One of these methods can also be used within the scope of the present invention in order to obtain one or more graphene or LiNbO or GaAs layers / films. A transfer method can be followed by structuring.

A passivation layer and / or a cladding can also be provided above, possibly on at least one of the active elements. A cladding is particularly suitable or designed to make the index contrast somewhat lower, so that roughness on the side walls does not have such a pronounced effect; Usually the losses in the waveguide (s) are reduced. A passivation layer preferably serves the purpose of protecting the arrangement or circuit from environmental influences, in particular water. A passivation layer can consist of a dielectric material, for example. Aluminum oxide (AL2O3) and silicon dioxide (S1O2) have proven to be particularly suitable.

An upper, final passivation layer expediently has openings or interruptions to the underlying contacts in order to enable an electrical connection. Openings or interruptions in a passivation layer can be or have been obtained, for example, by lithography and / or etching, in particular reactive ion etching. The or the respective active element can be connected to a contact or contact element on one side or on opposite sides. The contacts or contact elements can be in contact with connecting elements, in particular VIAs. For example, a connection to one or more integrated electronic components from the front-end-of-line of a chip or wafer can be achieved via the connecting elements. To be connected is to be understood in an expedient manner in an electrically conductive manner. It should be noted that, in particular in the case of a detector with only one active element, it can be provided that it is in contact with two contacts or contact elements, preferably on opposite sides, and in the case of a modulator with two active elements or one active Element and an electrode, it is true that these are each in contact with a contact or contact element. This is preferably done at those end regions or ends which are turned away from the region in that they lie one above the other or overlap in sections.

The or at least one of the active elements is or is expediently arranged relative to the longitudinal section of the waveguide in such a way that it is at least partially exposed to the evanescent field of electromagnetic radiation which is guided by this. Preferably, at least one active element is or will be arranged at a distance of less than or equal to 50 nm, particularly preferably less than or equal to 30 nm, from the longitudinal section of the waveguide, for example at a distance of 10 nm.

The or at least one of the active elements is also preferably characterized by an extension in the longitudinal direction in the range from 5 to 500 micrometers. It can also be that the or at least one of the active elements extends at least in sections on and / or within the longitudinal section of the waveguide, in the latter case for example between two segments of the waveguide.

In a further advantageous embodiment it is provided that the or at least one of the active elements is arranged on or above the waveguide in a region of the longitudinal section of the waveguide which is at least essentially trapezoidal when viewed in cross section and preferably follows the trapezoidal shape. Alternatively or additionally, it can be provided that the or at least one of the active elements is arranged in an at least substantially trapezoidal area of a planarization layer, viewed in cross section, on or above the planarization layer and preferably follows the trapezoidal shape.

In the case of waveguides, part of the electromagnetic radiation, especially light, is guided evanescent outside the waveguide. The interface of the waveguide is dielectric and accordingly the intensity distribution is described by the boundary conditions according to Maxwell with an exponential decrease. If an electro-optically active material, for example graphene, is brought into the evanescent field on or near the waveguide, photons can interact with the material, in particular graphene. There are four effects in graphs that lead to a photo signal. On the one hand, there is the bolometric effect, according to which the resistance of the graph increases due to the absorbed energy and an applied DC current is reduced. The change in DC current is then the photo signal. Another effect is the photoconductivity. Absorbed photons lead to an increase in the charge carrier concentration and the additional charge carriers ger reduce the resistance of the graph because of the proportionality of the resistance to the charge carrier concentration. An applied DC current increases and the change is the photo signal. There is also a thermoelectric effect, according to which a pn junction and a temperature gradient at this junction result in a thermal voltage for the p and n areas due to different lake basin coefficients. The temperature gradient is created by the energy of the absorbed optical signal. This thermal voltage is then the signal. The fourth effect is given by the fact that the excited electron-hole pairs are separated at a pn junction. The resulting photocurrent is the signal.

In the case of a modulator, as explained above, an electrical control electrode and an active element which is expediently insulated for this purpose with or made of at least one material whose refractive index changes as a function of a voltage or charges or an electric field, in particular made of graphene be provided or the electrode be made of a corresponding material, in particular graphene, so that two active elements are then jointly in the evacuating field during operation and perform the electro-optical function. Graphene, for example, can change its optical properties through a control voltage. In the particularly advantageous case of a graphene-dielectric-graphene arrangement, a capacitance is created and the graphs in the films influence one another. The capacitance consisting of the two active elements forming the graphene electrodes is charged by a voltage and the electrons occupy states in the graph. This results in a shift of the Fermi energy (energy of the last occupied state in the crystal) to higher energies (or due to symmetry to lower ones). If the Fermi energy reaches half the energy of the photons, these can no longer be absorbed because the free states required for the absorption process are already occupied at the correct energy are. In this state, the graph is consequently transparent because absorption is prohibited. By changing the voltage, the graph is switched back and forth between absorbing and transparent. A continuously luminous laser beam is modulated in its intensity and can thus be used to transmit information. The real part of the refractive index also changes with the control voltage. By changing the voltage, the phase position of a laser can be modulated via the changing refractive index and thus phase modulation can be achieved. The phase modulation is preferably operated in a range in which all states are occupied up to more than half the photon energy, so that the graph is transparent and the real part of the refractive index shifts significantly and the change in absorption plays a subordinate role.

Also in connection with both the photodetectors according to the first and second aspects and the modulators according to the third, fourth and fifth aspects of the invention, the following can also apply.

A waveguide and a longitudinal section of such is to be understood in particular as an element or a component that guides an electromagnetic wave, such as light. In order to guide the wave, a wavelength-dependent cross-section of an optically transparent material that is distinguished by a refraction index from an adjacent material that is also transparent for this wavelength is expediently provided. If the refractive index of the surrounding material is lower, the light is guided in the range of the higher refractive index. For the special case of a slit mode, two regions with a high refractive index are separated from a region with a narrow refractive index with respect to the wavelength, and the light is guided in the region of the low refractive index. In order to achieve low losses through scattering, a low side wall roughness is advantageous. As a rule, one or more waveguides will be provided, for example on a chip or a wafer. Part of a photodetector or modulator according to the invention will generally only be a longitudinal section of such, expediently a longitudinal section which extends below an active element of the latter. Of course, however, it is also not ruled out that a waveguide is regarded as a component of a photodetector or modulator according to the invention over its entire longitudinal extent. In other words, such a waveguide can also include the rest of the waveguide in addition to the longitudinal section of a waveguide that extends in particular below an active element.

As for the dimensions of waveguides, the following may apply, for example. The thickness is preferably in the range from 150 nanometers to 10 micrometers. The width and length of the waveguide can move in particular in the range of 100 nanometers and 10 micrometers.

A waveguide can be designed, for example, as a strip waveguide, which is characterized, for example, by a rectangular or square cross section, which then also applies to a longitudinal section of such a surface. A waveguide can alternatively or additionally also be designed as a ribbed waveguide with a T-shaped cross section. As an alternative or in addition, it is also possible that a waveguide is provided by a slotted waveguide.

A waveguide or longitudinal section of such a cross-section can include several sections or segments and be multi-part forms, such as a first, for example lower or left, and a second, for example upper or right segment or comprise them exist. It may be that one or more waveguide segments are characterized by a rectangular or square cross section. It is also possible that one or more segments of a waveguide are characterized at least in sections by a tapering cross section and / or at least in sections by a widening cross section.

If a waveguide has or consists of two or more segments, these can lie against one another or merge into one another or also be spaced apart from one another - for example with the formation of at least one gap or slot.

The longitudinal section of the waveguide comprises - both in the case of the aforementioned photodetectors according to the first and second aspect and the aforementioned modulators according to the third, fourth and fifth aspect of the invention - in a particularly expedient embodiment at least one material that is suitable for electromagnetic radiation of one wavelength of 850 nm and / or 1310 nm and / or 1550 nm is transparent or consists of such. It is particularly preferred for electromagnetic radiation in the wavelength range from 800 nm to 900 nm and / or from 1260 nm to 1360 nm (so-called original tape or O-band for short) and / or 1360 nm to 1460 nm (so-called extend band or E for short -Band) and / or 1460 nm to 1530 nm (so-called short band or S-band for short) and / or from 1530 nm to 1565 nm (so-called conventional band or C-band for short) and / or 1565 nm to 1625 nm ( so-called long band or short L-band) transparent. These tapes are already known from the field of communications engineering.

For example, the following materials have proven to be particularly suitable for the longitudinal section of the waveguide: titanium dioxide and / or aluminum nium nitride and / or tantalum pentoxide and / or silicon nitride and / or aluminum oxide and / or silicon oxynitride and / or lithium niobate and / or silicon, in particular polysilicon, and / or indium phosphite and / or gallium arsenide and / or indium gallium arsenide and / or aluminum gallium arsenide and / or at least one dichalcogenide, in particular two-dimensional transition metal dichalcogenide, and / or chalcogenide glass and / or heterostructures made of two-dimensional materials and / or resins or resin-containing materials, in particular SU8, and / or polymers or polymers containing materials, in particular OrmoClad and / or OrmoCore. The longitudinal section of the waveguide can comprise one or more of these materials or also consist of one of these materials or a combination of two or more of these materials. This can only apply to one or more, possibly all, waveguide segments. If the longitudinal section of the waveguide has a plurality of waveguide segments, these can all comprise the same material or materials or consist of the same material or materials. But it is of course also possible that two or more segments differ in terms of their material or their materials. It can be, for example, that at least one waveguide segment is characterized by a refractive index which is greater than the refractive index of at least one further waveguide segment. For example, in the event that several waveguide segments are sandwiched or stacked on top of one another, the outer segments can have a lower refractive index. Then the light is focused in the center of the waveguide arrangement. Purely by way of example for associated materials, an upper and a lower segment made of aluminum oxide with a middle segment made of titanium oxide located between them are mentioned. For a waveguide segment that lies between two active elements, a higher refractive index than the remaining segments has proven to be advantageous, since the light is then bundled in the area of the active elements.

Different materials of the segments of a waveguide (section) can also be advantageous for the reason that they are characterized by different etching rates. This can offer advantages in terms of manufacture, for example for necessary structuring.

The production of the longitudinal section of the waveguide can include or have included that a waveguide material is or has been applied, in particular deposited or spun on or transferred, and then preferably structuring of the applied waveguide material, in particular by means of lithography and / or reactive ion etching (RIE) will or was. For example, the same deposition methods can be used that were mentioned above in connection with the gate electrodes. The waveguide or longitudinal section of this can be formed in one or more parts. It can - particularly viewed in cross section - be formed from several waveguide segments or comprise several waveguide segments. These can both be spaced apart from one another and also lie directly against one another and be in contact with one another, for example because a segment was produced directly on another segment, for example by applying, for example, depositing material.

The longitudinal section of the waveguide furthermore preferably consists of at least one material whose refractive index differs from the refractive index a surrounding material distinguishes it or it comprises at least one such.

If the waveguide or waveguide longitudinal section is one that comprises two or more segments, of which at least two are spaced apart to form a gap, it can be provided in an advantageous embodiment that the gap is filled with at least one dielectric material whose refractive index is smaller than the refractive index of the material of the waveguide segments defining the gap.

For example, a planarization layer can surround the longitudinal section of the waveguide on one or more sides. As purely exemplary pairs of refractive indices in such a case, 3.4 (Si) for the longitudinal waveguide section and 1.5 (Si02) for the planarization layer or, in the case of dielectrics, 2.4 (Ti02) for the longitudinal waveguide section and 1.5 (Si02) for the planarization layer or 2 (SiN) for the longitudinal waveguide section and for the 1.47 planarization layer. It is particularly preferred that the refractive index of the longitudinal section of the waveguide is at least 20%, preferably at least 30% greater than the refractive index of the surrounding material.

The longitudinal section of the waveguide can furthermore be arranged on or above a planarization layer.

The planarization layer is then preferably characterized on the side on which the longitudinal section of the waveguide is arranged on it, at least in sections, by a roughness in the range from 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. ^{The abbreviation nm stands for nanometer (10 9} m) here and in the following in a well-known way.

Alternatively or additionally, the longitudinal section of the waveguide can be embedded at least in sections in a planarization layer, and the active element or - in the case of the modulator with two such - one of the active elements is arranged on the planarization layer. Here it can then preferably apply that the planarization layer on the side on which the active element is arranged on it is at least partially due to a roughness in the range from 1.0 nm RMS to 0.1 nm RMS, in particular 0.6 nm RMS 0.1 nm RMS, preferably 0.4 nm RMS to 0.1 nm RMS.

If the longitudinal section of the waveguide is both arranged on the upper side of a planarization layer and embedded in a planarization layer, two planarization layers are present.

To achieve a suitable roughness, chemical mechanical polishing and / or resist planarization can, for example, be or have been carried out.

With chemical-mechanical polishing, an object to be polished is usually polished by a rotating movement between grinding pads. The polishing is done chemically on the one hand and physically using a grinding paste on the other. By combining the chemical and physical effects, smooth surfaces can be obtained on a sub-nm scale.

The resist planarization includes, in particular, a one-time or repeated spin-on-glass spin-on and subsequent etching, preferably reactive ion etching (RIE for short). Intended to a surface, such as a Si0 ₂ surface, which has height differences, are planarized, this can be done by spin-on glass and etching. The spin-on-glass layer partially compensates for the height differences, ie valleys in the topology have a higher layer thickness after the spin-on-glass coating than neighboring elevations. The etching rate of spin-on-glass and, for example, S1O ₂ is similar or the same in an adapted RIE process. Adapted here is to be understood in particular to mean that the pressure, the gas flow, the composition of the gas mixture and the power are selected accordingly. If the entire spin-on-glass layer is etched by RIE after the spin-on-glass coating, the height difference has been reduced due to the planarizing effect of the spin-on-glass layer. Repetition can further reduce the height difference. The consumed SiO ₂ layer thickness must be taken into account when applying the S1O ₂ layer so that the desired S1O ₂ layer thickness is achieved after the last etching step. It should be emphasized that the resist planarization is not limited to S1O ₂ , but can also be used for other materials. It is expedient if an etching rate of the material can be achieved which is similar to that of spin-on glass or at least essentially corresponds to it. This condition is met for S1O ₂ and spin-on-glass. It should be noted that, for example, materials whose etching rate differs from that of spin-on-glass by a factor of 2 are also possible, in which case several passes are usually necessary. Applied as a liquid material, in particular spun on who can, for example, hydrogen silsesquioxane and / or a polymer. This vitrifies when it is subsequently baked out, which is why it is also known as spin-on glass. Hydrogen silsesquioxane (English: hydrogen silsesquioxane, HSQ for short) is a class of inorganic compounds with the formula [HSi03 / 2] n. The chemical-mechanical polishing and / or the resist planarization can in particular be carried out or have been carried out in such a way that a roughness in the range from 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 is or has been obtained.

Roughness in the areas mentioned has proven to be particularly suitable. They are particularly beneficial to avoid stress and tension in the layers above. In this context, reference should also be made to the article “Identifying suitable Substrates for high-quality graphene-based heterostructures” by L. Banszerus et al, 2D Mater., Vol. 4, No. 2, 025030, 2017 referenced.

It should be noted that in the event that the dielectric layer, which in the photodetector according to the first aspect of the invention can be provided in particular between the gate electrodes and the active element, is characterized on its upper side by a roughness in the aforementioned range , this can be achieved or can have been achieved in the same way, for example by CMP and / or resist planarization.

The atomic force microscopy (AFM) can be used as a measuring method for determining the roughness, in particular as described in the EN ISO 25178 standard. Atomic force microscopy is mainly discussed in Part 6 (EN ISO 25178-6: 2010-01) of this standard, which deals with measuring methods for determining roughness.

Furthermore, it can be provided that the planarization layer and / or any further planarization layer which may be present include one or more cover layers, which are preferably on a planarization treatment Treatment subjected surface are or are provided and which can be, for example, dichalcogenide layers or dichalcogenide heterostructures or also boron nitride layers. These materials are preferably deposited or transferred without the need for further chemical-mechanical polishing or further resist planarization, although it is not excluded that this is done again.

It can also be provided that the respective planarization layer or layers is obtained by deposition or is a layer obtained by deposition. In principle, the same methods can be used or have come to be used for the planarization layer that were mentioned above in connection with the gate electrodes (for example CVD, PVD, atomic layer deposition, transfer). This and the following explained for the planarization layer can also apply to the dielectric layer which may be present.

A layer can only comprise one or more layers. It can consist of just one material or several materials. For example, a layer can have two or more layers made of two or more different materials. It can of course also be the case that a layer has several layers, which, however, all consist of the same material. A layer with more than one layer can in particular be obtained or present because several layers, for example several atomic layers, are provided for their production, for example are or have been deposited.

The or the respective planarization layer can furthermore comprise 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 exist. Spin-on-Glass is usually a liquid substance with which wafers can be coated by spin coating. After spinning, a layer results on the wafer, the thickness of which depends on the surface topology. In this way, depressions are partially evened out and the spin-on-glass coating has a planarizing effect. Spin-on-Glass is usually heated after it has been applied and thus becomes a glass-like layer.

In the case of a modulator in particular, it can furthermore be provided that it comprises a diode or capacitance. For example, it can be an integrated III-V semiconductor modulator, as described in the article "Heterogeneously integrated III-V / Si MOS capacitor Mach-Zehnder modulator" by Hiaki, Nature Photonics volume 11, pages 482-485 (2017 ) is described.

If a diode is or is provided, it can, for example, comprise a plurality of layers of different compositions of, for example, InGaAsP, in particular in order to generate a pn junction and two contact areas.

The invention also relates to a semiconductor device comprising a chip and at least one, preferably a plurality of photodetectors and / or modulators according to the present invention, the photodetector or photodetectors and / or modulators preferably on the chip or on one on the chip or above the chip arranged layer are arranged.

Finally, the invention relates to a semiconductor device comprising a wafer and at least one, preferably a plurality of photodetectors and / or modulators according to the present invention, wherein the photodetector or photodetectors Death detectors and / or modulators are preferably arranged on the wafer or on a layer arranged on the wafer or above the wafer. The photodetector or photodetectors and / or modulators can, for example, be part of a photonic platform produced on the chip or wafer or bonded to the chip or wafer.

Bonded is to be understood in particular as meaning that the photodetector or photodetectors and / or modulators are or were not produced on or above the chip or wafer but rather separately from it and after their production - possibly also as part of a larger unit - are or have been connected to the chip or wafer, for example using a suitable intermediate layer.

If a chip or wafer is viewed in cross section, its vertical structure can be divided into different sub-areas. The lowest part is the front-end-of-line or FEOL for short, which usually comprises one or more integrated electronic components. The integrated electronic component (s) can be, for example, transistors and / or capacitors and / or resistors. Above the front-end-of-line is the back-end-of-line, or BEOL for short, in which there are usually various metal levels by means of which the integrated electronic components of the FEOL are interconnected.

A wafer comprises a plurality of areas which, following the dicing / comminuting / dicing, each form a chip or die. These areas are also referred to here as chip or die areas. Each chip area of the wafer preferably comprises a section or partial area of the in particular one-piece semiconductor substrate of the wafer. Preferred furthermore, each chip area has one or more integrated electronic components that extend in and / or on the corresponding area of the semiconductor substrate - viewed in cross section, in particular in the FEOL. It should be emphasized that the chip areas do not represent individual chips, that is to say that the wafer does not include any individual chips.

Both for a semiconductor device according to the invention and for a semiconductor device according to the invention it can apply that this comprises several structurally identical photodetectors according to the invention and / or several structurally identical modulators according to the invention or also several differently designed photodetectors according to the invention and / or several differently designed modulators according to the invention. It is also possible for some identical and additionally one or more different photodetectors and / or modulators to be present.

With regard to the embodiments of the invention, reference is also made to the claims below and to the following description of several exemplary embodiments with reference to the accompanying drawings. In the drawing shows:

FIG. 1 shows a partial section through a semiconductor device with an exemplary embodiment of a photodetector according to the first aspect of the invention;

FIG. 2 shows a plan view of the photodetector from FIG. 1;

FIG. 3 shows a partial section through a semiconductor device with a further exemplary embodiment of a photodetector according to the first aspect of the invention; FIG. 4 shows a partial section through a semiconductor device with an exemplary embodiment of a photodetector according to the second aspect of the invention;

FIG. 5 shows a partial section through a semiconductor device with an exemplary embodiment of an electro-optical modulator according to the third aspect of the invention; FIG. 6 shows a partial section through a semiconductor device with an exemplary embodiment of an electro-optical modulator according to the fourth aspect of the invention;

FIG. 7 shows a partial section through a semiconductor device with an exemplary embodiment of an electro-optical modulator according to the fifth aspect of the invention; and

FIG. 8 shows the steps of the method for producing the device according to FIG. 1.

All figures show purely schematic representations. In the figures, the same components or elements are provided with the same reference symbols.

FIG. 1 shows a partial section through an exemplary embodiment of a semiconductor device according to the invention.

This comprises a wafer 1, a planarization layer 2 produced on the wafer 1 and a plurality of photodetectors 3 produced on the planarization layer 2. In the partial section according to FIG. 1, only one of the photodetectors 3 is shown as an example. The wafer 1 in the present case comprises a one-piece silicon substrate 4 and a plurality of integrated electronic components 5 which, in the example shown, extend in the semiconductor substrate 4. The integrated electronic components 5, which can in particular be transistors and / or resistors and / or capacitors, are indicated in the schematic FIG. 1 only in a simplified manner by a line with hatching provided with the reference number 5. At a corresponding point in the substrate 4 there is a large number of integrated electronic components 5 in a well-known manner.

The wafer 1 has a front-end-of-line (short FEOL) 6, in which the plurality of integrated electronic components 5 are arranged and a back-end-of-line (short BEOL) 7, in which or via which the integrated electronic components 5 of the front-end-of-lines 6 are interconnected by means of various metal levels. The integrated electronic components 5 in the FEOL 6 and the associated interconnection in the BEOL 7 form integrated circuits of the wafer 1 in a well-known manner. A FEOL 6 is sometimes also referred to as a transistor front end and a BEOL 7 as a metal back end. The metal levels comprise a plurality of connection elements 8, which in the present case are given by so-called VIAs, which is the abbreviation for Vertical Interconnect Access. The VIAs 8 are made of metal, for example copper, aluminum or tungsten.

The planarization layer 2 is produced on the top 9 of the wafer 1 facing away from the front-end-of-line 6 and consists of an electrical material. In the present case, the planarization layer 2 consists of Silicon dioxide (S1O2), whereby this is to be understood as an example and other materials can also be used.

In the exemplary embodiment shown, the planarization layer 2 is produced by deposition of the corresponding coating material, here S1O2, on the top side 9 of the wafer 1 facing away from the front-end-of-line 6 and subsequent planarization processing of the deposited material on the top side facing away from the wafer 1 10 obtained layer. The planarization layer 2 is characterized in the present case by a roughness of 0.2 nm RMS due to the processing on its upper side 10 facing away from the wafer 1, this being understood as an example.

In the example shown, the planarization layer 2 extends over the entire top side 9 of the wafer 1. The material of the planarization layer 2 was deposited over the entire surface area 9 of the wafer 1. This is therefore characterized by a diameter which at least essentially corresponds to that of the wafer 1.

The photodetectors 3 produced on the planarization layer 2 are exemplary embodiments of a photodetector 3 according to the invention in accordance with the first aspect of the invention. In the exemplary embodiment, these are all structurally identical, although this is not to be understood as restrictive.

In the following, the structure of the detectors 3 and also their lowering position are described using the one detector 3 shown in FIG. 1 as an example. Also with regard to the examples of further detectors and modulators described below (cf. FIGS. 3 to 6), the structure is explained in each case with the aid of the one example recognizable in the partial sections. The (respective) photodetector 3 comprises a longitudinal section 12 of one of the waveguides 11, specifically that longitudinal section over which an active element 13 of the photodetector 3 overlaps. In FIG. 2, which shows the active element 13 and the underlying waveguide 11 in a purely schematic plan view, the longitudinal section 12 of the waveguide covered here by the active element 13 is shown with dashed lines.

Particularly suitable waveguide materials are dielectrics, preferably titanium dioxide, which was also used in the exemplary embodiment shown. Alternatively or additionally, one or more waveguides 11 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 also made of semiconductors such as silicon, indium phosphide, gallium arsenide, indium gallium arsenide, aluminum gallium arsenide or dichalcogenides can be used or chalcogenide glass or polymers such as SU8 or Ormo-Clad and / or OrmoCore can be provided.

The longitudinal section 12 of the waveguide 11 is here by two in the longitudinal direction and at least substantially parallel to each other extending waveguide segments 12a, 12b, which in the transverse direction (in the figure from left to right or vice versa) with the formation of a gap between them 14 spaced apart from each other is formed. It is therefore a slotted waveguide. By means of such a waveguide 11, the optical mode is guided in the gap 14 during operation. In the example shown, the two waveguide segments are characterized by a rectangular cross section. The gap 14 can, for example, be filled with S1O2.

The two waveguide segments 12a, 12b each stand on at least one side, in the present case on their side facing the active element 13 a gate electrode 15a, 15b made of silicon in contact. The gate electrodes 15a, 15b are presently formed by a silicon layer or silicon coating produced on the respective waveguide segment 12a, 12b.

The active element 13 comprises at least one material or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption. In the example shown, it is given by a graphene film 13. Graphene can also change its refractive index (refractive index and / or absorption) as a function of a voltage and / or of charge and / or an electric field. It should be emphasized that it is also possible for the active element 13 to be provided by a film with or made of at least one other or further electro-optically active material, for example a film with or made of a dichalcogenide-graphene fletero structure consisting of at least one layer of graphene and at least one layer of a dichalcogenide, or by a film that comprises at least one layer of boron nitride and at least one layer of graphene.

As can be seen from FIG. 1, the graphene film 13 is arranged on the upper side 16, facing away from the wafer 1, of a further planarization layer 17 in which the waveguide 11 and thus its longitudinal section 12 is embedded. The further planarization layer 17 consists of the same material as the planarization layer 2 and is characterized on its upper side 16 by the same roughness as the upper side 10 of the layer 2. However, this is only an example and is not intended to be limiting. By means of the Ga teel electrodes 15a, 15b provided on the waveguide segments 12a, 12b, a pn junction can be realized in the graphene film 13 above the gap 14 and thus in the area of an optical mode guided in the gap 14 of the waveguide 11 during operation. A pn junction can be used to separate electron-hole pairs generated by absorption and thus to generate a photocurrent. The thermoelectric effect can also be used in graphs, whereby Seebeck coefficients with opposite signs arise in the p and n regions, which result in a thermal voltage when heated by the absorbed energy (the photons).

It should be noted that the connection (not shown) of the gate electrodes 15a, 15b for the voltage supply can be, for example, laterally next to the VIAs 8.

The photodetector 3, specifically its graphene film 13, is electrically conductively connected to at least one of the integrated electronic components 5 of the front end of lines 6 of the wafer 1. As can be seen in the schematic sectional views according to FIG. 1, the connection is via the VIAs 8 of the back-end-of-lines 7 of the wafer 1 and further VIAs 8, which extend through the planarization layer 2 and any other existing thereon Layers or elements, in the present case extending the further planarization layer 17, are realized. Specifically, graphene film 13 is electrically conductively connected at opposite end areas via contacts or contact elements 18 with the upper end of VIAs 8, which extend through further planarization layer 17 and planarization layer 2 to the back-end-of-line 7 of wafer 1 the. In the plan view from FIG. 2, those with the contact elements 18 in Connected VIAs 8, which are below the former, indicated with a thin line.

In the example shown, a passivation layer 19 is provided on the graphene films 13, which comprises or consists of aluminum oxide (AL2O3) and / or silicon dioxide (SiO2).

A photodetector 3, as shown in FIG. 1 and FIGS. 3 and 4, which are explained below, can in particular be used in a manner known per se for signal conversion back from the optical to the electronic world.

To obtain the semiconductor device shown in FIG. 1, in a first step S1 (see FIG. 8) the wafer 1 with the integrated circuits comprising the integrated electronic components 5 and the metallization including the VIAs 8 is provided. The wafer 1 can be any desired wafer 1 of a conventional type, which has been obtained by a previously known production method. In a second step S2, the planarization layer 2 is produced on the back-end-of-line 7 of the wafer 1. For this purpose, a coating material, in this case silicon dioxide (Si0 ₂ ), is applied, which can be done, for example, by chemical vapor deposition, such as low-pressure chemical vapor deposition or plasma-assisted chemical vapor deposition, or physical vapor deposition or by spin-on spin-on glass. PECVD is used here. After the coating material has been deposited, the upper side of the coating obtained is subjected to a planarization treatment (step S3), in this case a resist planarization, as a result of which an upper side 10 with a roughness of 0.2 nm RMS is obtained. The resist planarization includes a single or repeated spin-on-glass spin-on and subsequent etching, in the present case reactive ion etching (RIE). The spin-on-glass layer partially compensates for the height differences, ie valleys in the topology have a higher layer thickness after the spin-on-glass coating than neighboring elevations. If, after the spin-on-glass coating, the entire spin-on-glass layer is etched, for example by RIE, the height difference has been reduced due to the planarizing effect of the spin-on-glass layer. The height difference can be further reduced by repetition until the desired roughness is obtained. It should be noted that an upper side 10 of the planarization layer 2 with correspondingly low roughness can alternatively also be obtained, for example, via chemical-mechanical polishing (CMP).

In a next step S4, which in the present case represents the first step in the manufacture of the detector 3, the (respective) waveguide 11 with the gate electrodes 15a, 15b is manufactured. For this purpose, waveguide material, in front of titanium dioxide (T1O2), is deposited, in particular over the entire top surface 10 of the planarization layer 2 obtained. Atomic layer deposition (ALD) or a transfer printing process can also be carried out. In the present case, in analogy to the planarization layer 2, LPCVD is used.

Subsequently, the coating material for the gate electrodes 15a, 15b, gate electrode material, in this case silicon, is deposited, for example by means of PVD or CVD processes and preferably also flat. Lithography and structuring, in particular by means of reactive ion etching (RIE), are carried out in order to obtain the individual waveguides 11 with the individual waveguide segments 12a, 12b with the gap 14 in between and the individual gate electrodes 15a, 15b.

In a next step S5, the further planarization layer 17 is produced on the waveguides 11 with gate electrodes 15a, 15b provided thereon and the top side 10 of the planarization layer 2. In the present case, this is obtained completely analogously to the planarization layer 2 by deposition by means of PECVD and resist planarization. During or due to the material separation, the gap 14 is also filled with S1O2. As a result of the resist planarization, the section of the further planarization layer 17, which is trapezoidal in cross section, results above the waveguide 11 (see FIG. 1).

With regard to the further planarization layer 17, it is also true that, as an alternative to LPCVD and CMP, other of the aforementioned methods can be used and a different planarization treatment, such as CMP, and / or further planarization is possible, as described above for the planarization layer 2.

The planarization layer 2 and further planarization layer 17 can comprise one or more cover layers which are or will preferably be provided on the surface subjected to the planarization treatment and which can be dichalcogenide layers or dichalcogenide heterostructures or boron nitride layers, for example. These materials are preferably deposited or transferred without the need for further chemical-mechanical polishing or further resist planarization, and it is not excluded that this is done again. For the sake of completeness, it should be noted that in the event that a semiconductor device according to the invention should also have areas without a further planarization layer 17, for example also areas in which the structure corresponds to that according to FIGS any layers thereon) is then partially removed again, in particular by lithography and etching. In step S6, the VIAs 8 are produced through the planarization layer 2 and the further planarization layer 17. In principle, this can be done in any manner previously known from the prior art. In particular, first of all the areas in which they should extend are preferably defined by lithography and dry-chemically etched by means of RIE. Then it is metallized and the metallized surface is structured, for example by means of CMP (Damascene process) or by means of lithography and RIE. It is both possible that the VIAs 8 are produced after the completion of the further planarization layer 17 through both planarization layers 2, 17 or after completion of the first layer 2 sections of this through the first planarization layer 10 and after completion of the second 17 sections of this through the second layer 17.

In step S7, the active element of the (respective) detector 3 given by a graphene film 13 is provided on the upper side 16 of the further planarization layer 17, for example deposited on the upper side 17.

The graphene film 13 of the (respective) detector 3 can be deposited using a transfer method, for example, as described in more detail above. Then in particular one on a separate substrate or a separate metal foil or a separate Germani The graphene film produced around the wafer is transferred to the further planarization layer 17. It is also possible for the (respective) graphene film 13 to be produced directly on the further planarization layer 17. This can include material deposition, for example.

If a transfer method is used, it is possible that the passivation layer is already provided on the upper side of the respective graphene film 14, this has been deposited or deposited thereon, and is then transferred with it. As an alternative to this, a passivation layer can also be deposited or deposited after the transfer or production of the graphene film 13 or the graphene films 13.

It is also possible for a full-area graphene film and / or a full-area passivation layer to be produced on the further planarization layer 17, which extend over the entire surface of the further planarization layer 17. In this case, there is then a structuring, in particular by lithography and RIE, in order to keep the individual graphene films 13 as active elements of a plurality of detectors 3.

The contact elements 18 are then produced (step S8), preferably by metal being deposited over the entire surface and then again structuring by means of lithography and RIE to obtain the individual elements 18.

In a penultimate step S9, the upper passivation layer 19 is deposited preferably from Al2O3 and / or S1O2. In this, openings, in particular for contact elements, are then expediently finally produced by means of lithography and RIE (step S10). There will be preferably made openings to contact elements, which serve to connect the photonics and / or electronics to the outside.

FIG. 3 shows a further exemplary embodiment of a photodetector 3 according to the first aspect of the invention.

This differs from that according to FIG. 1 essentially in that the two waveguide segments 12a, 12b of the longitudinal section 12 of the waveguide 11 do not have a rectangular cross-section and there is no further planarization layer 17, but the active element, which here too - for example - through a graphene film 13 is provided on one of the gate electrodes 15a, 15b in which a dielectric layer which cannot be recognized is disposed. The dielectric layer represents a gate dielectric. In the present case, it is distinguished on its upper side by a roughness of 0.2 nm RMS. In the present case, their thickness is 15 nm, these two values being understood to be purely exemplary.

As can be seen, each of the two waveguide segments 12a, 12b has an end region facing the gap 14 located between the two segments 12a, 12b, the cross section of which widens in sections in the direction of the gap 14. As can be seen, the two end regions and the gap 14 result in a central, trapezoidal region. The sections or areas of the segments 12a, 12b adjoining this trapezoidal area on both sides are distinguished, as can be seen, by a constant thickness.

The two gate electrodes 15a, 15b each extend in the transverse direction only over a section of the upper side of the respective segment 12a, 12b. The VIAs 8 assigned to the gate electrodes 15a, 15b and each in contact with a gate electrode 15a, 15b can be seen in FIG. This is used to establish a connection to at least one integrated electronic component 5 from the FEOL 6, but this cannot be seen in the figure for reasons of simplified representation. As can be seen, these VIAs 8 each extend through the planarization layer 2 and that waveguide segment 12a, 12b on which the respective Ga teel electrode 15a, 15b is arranged. The supply of voltage to the gate electrodes 15a, 15b is ensured via the VIAs 8. In the example from FIG. 3, a pn junction in the graphene film 13 can also be made via the gate electrodes 15a, 15b during operation, namely also here in the region extending above the gap 14 in which the optical mode is guided during operation , are obtained. To obtain the arrangement according to FIG. 3, steps S1 to S3 can be identical to those for the lowering position of the arrangement from FIG.

In step S4, an adapted etching, in particular RIE, is used for the fixing of the waveguide 11 and gate electrodes 15, 15b after waveguide material has also been flatly deposited here, for example in the same way as described above in connection with FIG -Process carried out to get the trapezoidal area with the beveled edges. An isotropic etching behavior of the RIE process can be obtained, for example, by an increased process pressure and an adapted gas mixture compared to the anisotropic etching process. Due to the increased process pressure, for example 20 mTorr compared to 10 mTorr, the etching process has a non-directional component, which causes a higher level of removal on the upper edge due to the longer etching time. At first the VIAs 8 for the gate electrodes 15a, 15b and then again material for the gate electrodes 15a, 15b, such as silicon, is deposited.

Then the (respective) slot 14 and the gate electrodes 15a, 15b are etched. As a result, the gate electrode layer, which initially covers the entire surface, is "divided".

Step S5 for the arrangement from FIG. 1 is omitted here, since no further planarization layer 17 has to be produced here. Here, therefore, the VIAs 8 for the graphene film 13 are produced in step S5

In step S6, the dielectric layer is first produced on the upper side of the gate electrodes 15a, 15b and preferably resist-planarized on its upper side in order to achieve the aforementioned roughness, and then the graphene film 13 is provided thereon.

The trapezoidal shape favors that the active element, in the present case the graphene film 13, conforms to the gate electrodes 15a, 15b or the dielectric layer, in particular also the beveled edges. As a result, the graph always lies on the dielectric layer on the electrodes 15a, 15b and can be particularly well controlled electrostatically. A particularly homogeneous electric field can also be achieved.

The steps following the provision of the (respective) graphene film 13 can correspond to those for the arrangement from FIG. 1 (in particular production of the contact elements 18, production of the passivation layer 19 and provision of openings in this).

FIG. 4 shows an embodiment of a photodetector 3 according to the second aspect of the invention. This also comprises a longitudinal section 12 of a waveguide 11 and an active element 13 which comprises at least one material or consists of at least one material that absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption. In the detector according to FIG. 3, too, the active element is provided, for example, by a graphene film 13.

In contrast to the examples from FIGS. 1 and 3, the waveguide 11 and its longitudinal section 12 belonging to the detector 3 are formed in one piece here. Specifically, it is a strip waveguide with a rectangular cross-section.

Another difference is given by the fact that two support elements 20 are arranged on opposite sides of the longitudinal section 12 of the waveguide 11, forming two gaps 21 at a distance therefrom. The support elements 20 are arranged at a distance from the longitudinal section 12 of the waveguide 11 in the transverse direction. The two gaps 21 are free of material. The present is in this vacuum.

The support elements 20 can consist of the same material as the longitudinal section 12 of the waveguide 11, this being understood as an example. As can be seen, the active element 13 overlaps in the transverse direction the longitudinal section 12 of the waveguide 11 and the two gaps 21 and, from sections on, the two support elements 20.

In contrast to the examples from FIGS. 1 and 3, where it rests in a trapezoidal area, the graphene film 13 is also flat. As far as the wafer 1, the planarization layer 2 and the passivation 19 are concerned, the arrangement from FIG. 4 corresponds to that from FIG. As can be seen, this also has no further planarization layer 17. In addition, this detector 3 does not include any gate electrodes.

For setting the arrangement from FIG. 4, steps S1 to S3 can again be identical to those that were described in connection with FIG.

In a step S4, the waveguides 11 and support elements 20 are then produced. For this purpose, waveguide material, for example the same as in the previous examples, is deposited over a large area and the column 21 is then obtained by lithography and etching.

Then the VIAs 8 are produced, which here extend through the one planarization layer 2 and one of the support elements 20 each (step S5). In a step S6, the active elements are provided, for example in the form of Gra phenfilmen 13, which is expediently done by a transfer process, as described in more detail above.

The remaining steps can again correspond to those that followed the provision of the active elements 13 in the previous examples (in particular production of the contact elements 18, production of the passivation layer 19 and provision of openings in this). FIG. 5 shows an embodiment of an electro-optical modulator 22 according to the third aspect of the invention.

This also comprises a longitudinal section 12 of a waveguide 11, which however comprises four waveguide segments 12a, 12b, 12c, 12d extending in the longitudinal direction and at least substantially parallel to one another.

Since it is a modulator 22, it also has two active elements 13a, 13b which comprise at least one material or consist of at least one material whose refractive index depends on a voltage and / or the presence of charge and / or an electric field changes. In the example shown, the two active elements are given by two graphene films 13a, 13b. Of the two active elements 13a, 13b, the lower one 13a is arranged on the upper side 10 of the planarization layer 2.

It should be noted that, as an alternative to the fact that two active elements 13a, 13b are provided, only one active element and one conventional electrode, for example made of a metal, can also be provided and can be arranged correspondingly to one another.

With regard to the four waveguide segments 12a-12d, a lower one of the waveguide segments 12a is arranged between the two active elements 13a, 13b and a middle one of the waveguide segments 12b is arranged above the two active elements 13a, 13b, specifically on the upper active element 13b is. In other words, there is a sandwich-like configuration with or from (in FIG. 5 from bottom to top) first active element 13a, lower waveguide segment 12a, second active element 13b and middle segment 12b. The upper active element 13 extends within the longitudinal section 12 of the waveguide. The waveguide segments 12a-12d can all be made of the same material.

The lower and the middle waveguide segment 12a, 12b serve at the same time as passivation and etch protection. In particular, the segment 12a is part of the waveguide and at the same time also protection for the element 13a when the element 13b is etched. Then 12a serves as an etch stop layer and as a passivation layer to protect the graphene 13a. The segment 12b is in particular also an etch stop layer for structuring the parts 12c and 12d during the production of the region 14.

The two remaining, upper waveguide segments 12c, 12d are arranged above half of the middle waveguide segment 12b, in the present case on its upper side. The two upper waveguide segments 12c, 12d are spaced from one another in the transverse direction, forming a gap 14 extending between them. The two upper waveguide segments 12c, 12d thus lie next to one another on the middle segment 12b and the gap 14 lies between them. It applies that exactly one gap 14 is provided above the two active elements 13. The gap 14 is filled with the material of the layer 19.

The extent of the lower and middle waveguide segments 12a, 12b in the transverse direction exceeds, as can be seen, the extent of the two upper segments 12c, 12d in this direction by a multiple. The cross-section of the segments 12a-12d is rectangular.

The two active elements 13a, 13b are spaced apart from one another - by the lower waveguide segment 12a - and are furthermore arranged offset from one another in the transverse direction in such a way that they lie on top of one another in sections in an overlap region 23. It aligns or overlaps your portion of the one active element 13 with a portion of the other active element 13. Specifically, the facing end areas are one above the other or are aligned, whereby the overlapping area 23 is formed. As can be seen from FIG. 5, the overlapping area 23 lies below the gap 14 formed between the two segments 12c, 12d, and is in alignment therewith.

The extent of the overlap area 23 and the extent of the gap 14 in the transverse direction are adapted to one another. Specifically, the extent of the overlap region 23 in the transverse direction is approximately 1.3 times the extent of the gap 14 in this direction. For example, it can also correspond to 1.0 times or 0.8 times, that is to say it can have the same or a lesser extent in this direction. In particular, the smaller the overlap, the lower the capacitance and the faster the modulator.

In the case of the modulator 22 with two active elements 13, it is also true that this, specifically its active elements 13, are connected to at least one integrated electronic component 5 from the FEOL of the wafer 1. In this case, each active element 13 is connected to a VIA 8 via a contact element 18 assigned to it and in contact therewith, which extends through the planarization layer 2 (VIA 8 for the active element 13 on the left in FIG. 5) or the planarization layer 2 and the Waveguide segment 12a (VIA 8 for the active element 13 on the right in FIG. 5) and, together with further VIAs 8 in BEOL 7, ensures the connection.

An electro-optical modulator 22, as shown in FIG. 5 and also FIGS. 6 and 7, which will be explained below, can be used in a manner known per se, in particular for optical signal coding. To obtain the arrangement from FIG. 5, steps S1 to S3 can again be identical.

Subsequently, in a step S4, the first, lower graphene film 13a can be provided as the lower active element. This can take place exactly as described above for the one active element 13 of the detectors 3. This can accordingly include, for example, a full-area separation of material and subsequent structuring. The contact element 18 belonging to this can then be produced, again in exactly the same way as the contact elements 18 from FIGS. 1, 3 and 4.

In step S6, the lower waveguide segment 12a is then produced, which can preferably - in analogy to the segments 12a, 12b from the preceding figures - comprise a material deposition and subsequent structuring. The same materia lien come into question as waveguide material that were mentioned for the previous examples.

In step S7, the second, upper graphene film 13b is provided on the upper side of the segment 12a, preferably in the same way as the first, lower 13a.

In step S8, the contact element 18 is produced for this. In step S9, the middle segment 12b is produced - preferably like the lower 12a - and in step S10 the two upper segments 12c, 12d are produced on the upper side of the middle segment 12c. Here, too, it applies that a waveguide material is deposited in the manner described above and then a structuring to obtain the two adjacent segments 12c, 12d enclosing the gap 14 between them can be done. It should be noted that it is possible that the material deposition for the middle segment 12b and the upper two segments 12c, 12d takes place with an interruption or separately, for example if different waveguide materials are used. However, it is also not excluded that the material required for the middle segment 12b and the material required for the upper segments 12c, 12d are applied in a deposition process without interruption and the segments 12b, 12c, 12d are obtained by the subsequent structuring

This is then preferably followed by the steps for obtaining the passivation layer 19 (S11) and the openings therein (S12), as explained above in connection with the preceding figures. The gap 14 fills with or due to the material deposition for the layer 19 with its material.

FIG. 6 shows an exemplary embodiment of a modulator 22 according to the fourth aspect of the invention. This differs from that according to FIG. 5 essentially in that there is a gap 14 not above, but below the active elements 13, which are also provided here - for example - by graphene films 13, and the longitudinal section 12 of the waveguide 11 is not four, but five segments 12a, 12b, 12c, 12d, 12e.

Specifically, two lower ones of the waveguide segments 12a, 12b are arranged below the active elements 13 and are spaced apart from one another in the transverse direction to form a gap 14 extending between them, and a first middle one of the waveguide segments 12c is arranged between the two active elements 13, and one second middle waveguide tersegment 12d is arranged above the two active elements 13, specifically on the top of the upper active element 13, and an upper waveguide segment 12e is arranged above the second middle waveguide segment 12d, specifically on its top. In this example there is thus a sandwich-like structure, which - from bottom to top - the two lower waveguide segments 12a, 12b, the lower active element 13a, a first central waveguide segment 12c, the upper active element 13b, a second central waveguide segment 12d and comprises on the top of the upper waveguide segment 12e. Here both active elements 13 extend within the longitudinal section 12 of the waveguide 11.

The two lower waveguide segments 12a, 12b and the first middle waveguide segment 12c also serve here at the same time as passivation and etch protection.

The same applies to the extension of the gap 14 in the overlap region 23 in the transverse direction as with regard to FIG. 5. To obtain the arrangement from FIG. 5, steps S1 to S3 can again be identical.

In a step S4, the two waveguide segments 12a, 12b are first produced on the top 10 of the planarization layer 2, with waveguide material being deposited for this purpose, preferably in the same way as in the previous examples, which initially results in a continuous layer, and then by structuring , which preferably includes lithography and etching, in particular RIE, the gap 14 is produced, filled with a dielectric material, for example S1O2, and the surface is preferably planarized, for example by CMP and / or resist planarization. The VIA 8 assigned to the graphene film 13 on the left in FIG. 5 can then be produced (step S5), which extends through the planarization layer 2 and the lower segments 12a on the left in FIG. 5, which can be done as described above.

Next, the first, lower graphene film 13 is provided (step S6), which can also be done as in the previous examples. The lower graphene film 13 is preferably arranged in such a way that it completely overlaps the gap 14 - as can be seen in FIG. 5 - in the transverse direction.

The associated contact element 18 can then be produced as described above (step S6) and then the first middle waveguide segment 12c, then the VIA 8 for the second, upper graphene film 13 (step S7), then the second, upper graphene film 13 ( S8), like the first, then the second middle segment 12d (S9) and the upper segment 12e (S10). The lowering position of the segments 12c, 12d and 12e can, for example, be analogous to the lowering position of the segments 12a to 12d from FIG .

Finally, the steps described above for obtaining the passivation layer 19 (S11) and the openings in this (S12) can also be carried out here.

In Figure 7, an embodiment of a modulator 22 is shown according to the fifth aspect of the invention. This differs from the example from FIG. 6 solely in that a second gap 14 is additionally provided above the active elements, again given by way of example by graphene films 13. Instead of the strip-shaped waveguide segment 12e as in FIG. 6, two adjacent segments 12e and 12f spaced from one another to form the second gap 14 are also provided above the graphene films 13 on the upper side of the second middle segment 12d. It should be noted that the second, upper gap 14 is also filled with its material during or due to the material deposition for the layer 19

In this example, there is a sandwich-like structure, which - from bottom to top - the two lower waveguide segments 12a, 12b, the lower active element 13a, a first middle waveguide segment 12c, the upper active element 13b, a second middle waveguide segment 12d and on top of it Upper side comprises two adjacent, upper waveguide segments 12e, 12f. Here, too, the two active elements 13 extend within the longitudinal section 12 of the waveguide 11.

As can be seen in Figure 6, the overlap area 23, which the two active elements 13 form due to the offset, is above the one gap 14, specifically that between the lower segments 12a and 12b, and below the other gap 14, specifically that between the two between the upper segments 12e and 12f.

The lower gap 14, the overlap area 23 and the upper gap 14 are aligned. It also applies here that the extent of the overlap region 23 and the extent of both gaps 14 in the transverse direction are adapted to one another. Specifically, the extent of the overlap region 23 in the transverse direction is approximately 1.3 times the extent of the upper gap 14 and the lower gap 14 in this direction. For example, it can also be 1.0 or 0.8 times.

The same procedure can be used to obtain the arrangement from FIG. 7 as for that from FIG. 6, with the only difference that the upper gap 14 must also be etched. As a result, the two upper segments 12e and 12f with the gap 14 between them are then obtained on the upper side of the second central waveguide segment 12d instead of the one upper segment 12e.

As noted above, the examples of semiconductor devices according to the invention each comprise a plurality of photodetectors 3 or modulators 22, of which the partial sections only show one by way of example. In the illustrated exemplary embodiments of semiconductor devices according to the invention, all photodetectors 3 or modulators 22 can each be structurally identical. The correspondence then enables a particularly simple, rapid provision. However, it should be emphasized that it is of course also possible for a semiconductor device according to the invention to include various of the examples of photodetectors 3 and / or modulators 22 shown in FIGS. 1 and 3 to 6, for example both detectors 3 according to FIG FIG. 5. There can also be more than two different examples, for example also one or more of all shown photodetectors 3 and / or of all shown modulators 22. It should be noted that the arrangements provided on the wafer 1, which include the layers 2, possibly 17 and 19 as well as photodetectors 3 and / or modulators 22, can also each be regarded and referred to as a photonic platform. It should also be noted that, as an alternative to the fact that the photonic platform is produced on the BEOL 7 of the wafer 1 as in the exemplary embodiment described, it is in principle also possible for it to be produced separately and bonded to the wafer 1. After a semiconductor device according to the invention has been completed, a plurality of semiconductor devices can be produced from this in a simple and fast manner, specifically by means of mere dicing, in other words comminuting, each of which is provided by a chip with integrated photonics built on it with one or more photodetectors 3 and / or Modulators 22 formed in accordance with the present invention can be obtained.

The “bare chips” with photodetectors 3 and / or modulators 22 obtained by dicing can then, as is also known from conventional bare chips, be inserted into housings (English: packages) and put to further use.

A chip with one or more such chips obtained by dicing the semiconductor device with the wafer 1 and the photo detectors 3 and / or modulators 22 is an exemplary embodiment of a semiconductor device according to the invention.

It should be noted that all of the partial sectional views show only a comparatively very small section, specifically a section that shows only a small part of the wafer 1 or a chip obtained after dicing. All partial sections thus represent both sections by an embodiment of a semiconductor device according to the invention as well as by an embodiment of a semiconductor device according to the invention. It should also be noted that a plurality of photodetectors 3 and / or modulators 22 can already be provided above a single chip, for example several tens, several hundred or even several thousand, depending on the application.

Claims

Expectations

1. Photodetector (3) comprising a longitudinal section (12) of a waveguide (11), the two in the longitudinal direction and at least substantially parallel to each other extending waveguide segments (12a, 12b), which are preferably in the transverse direction with the formation of a between them extending gap (14) are spaced apart, includes or is formed thereby, and an active element (13) which overlaps the longitudinal section (12) of the waveguide and comprises at least one material or consists of at least one material that at least electromagnetic radiation absorbs a wavelength and generates an electrical photo signal as a result of the absorption, the two waveguide segments (12a, 12b) each on at least one side, in particular on the side facing the active element (14), at least in sections with a preferably comprising or made of silicon Silicon existing gate electrode (15a, 15b) are in contact.

2. Photodetector (3) according to claim 1, characterized in that the gate electrodes (15a, 15b) each on their underside with the top side of a waveguide segment (12a, 12b) and each with their top side with the underside of one between the active element (13 ) and the waveguide segments (12a, 12b) provided dielectric layer in contact.

3. Photodetector (3) according to claim 1 or 2, characterized in that the gate electrodes (15a, 15b) comprise or consist of a material which is transparent and / or electrically conductive for electromagnetic radiation at least one wavelength.

4. The photodetector (3) according to any one of the preceding claims, characterized in that each of the two gate electrodes (15a, 15b) is assigned a connecting element (8) in contact therewith and in each case one of the connecting elements (8) extends through one of the shafts - Conductor segments (12a, 12b) extends.

5. Photodetector (3) according to one of the preceding claims, characterized in that the active element (13) overlaps the two waveguide segments (12a, 12b) and the gap (14) in between at least in sections.

6. Photodetector (3) comprising a longitudinal section (12) of a Wel lenleiters (11), and an active element (13) which comprises at least one material or consists of at least one material that absorbs electromagnetic radiation at least one wavelength and as a result From the absorption generates an electrical photo signal, with two support elements (20) on opposite sides of the longitudinal section (12) of the Wellenlei age (11) to form two columns (21) spaced from this angeord net, the two columns (21) free are made of material, and wherein the active element (13) overlaps the longitudinal section (12) of the waveguide (1) and the two gaps (21) and at least sections of the two support elements (20), preferably in the transverse direction.

7. photodetector (3) according to claim 6, characterized in that the active element (13) rests on the upper side of the longitudinal section (12) of the waveguide (11) facing this and / or on the upper sides of the support elements (20) facing this .

8. photodetector (3) according to any one of the preceding claims, characterized in that it is the at least one material of the active element (13), which absorbs electromagnetic radiation of at least one wavelength and generates an electrical photo signal as a result of the absorption in order to generate graphene and / or at least one dichalcogenide, in particular two-dimensional transition dichalcogenide, and / or heterostructures made 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.

9. modulator (22) comprising a longitudinal section (12) of a waveguide (11) which comprises or is formed by four waveguide segments (12a, 12b, 12c, 12d) extending in the longitudinal direction and at least substantially parallel to one another, and two active elements (13) that comprise at least one material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, or such an active element (13 ) and an electrode, a lower one of the waveguide segments (12a) being arranged between the two active elements (13) or between the active element (13) and the electrode, and a middle one of the waveguide segments (12b) above that of the active ones Elements (13) or above the active element (13) and the electrode is arranged, and the two remaining, upper waveguide tersegmente (12c, 12d) above the central waveguide ersegmentes (12b) are arranged, wherein the two upper waveguide segments (12c, 12d) are preferably spaced from one another in the transverse direction with the formation of a gap (14) extending between them.

10. modulator (22) comprising a longitudinal section (12) of a waveguide (11) which has five waveguide segments (12a, 12b, 12c, 12d, 12e) comprises or is formed by these, and two active elements (13) which comprise at least one material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field , or such an active element (13) and an electrode, two lower of the waveguide segments (12a, 12b) below the active elements (13) or below the active element (13) and the electrode angeord net and preferably in the transverse direction to form a between them extending gap (14) are spaced apart, and a first middle of the waveguide segments (12c) between the two active elements (13) or between the active element (13) and the electrode is arranged, and a second middle waveguide segment (12d) is arranged above the two active elements (13) or above the active element (13) and the electrode, and an upper We Llenleitersegment (12e) is arranged above the second central waveguide segment (12d).

11. Modulator (22) comprising a longitudinal section

(12) a waveguide (11) which comprises or is formed by six waveguide segments (12a, 12b, 12c, 12d, 12e, 12f) extending in the longitudinal direction and at least substantially parallel to one another, and two active elements

(13), which comprise at least one material or consist of at least one material whose refractive index changes as a function of a voltage and / or the presence of charge and / or an electric field, or such an active element (13) and an electrode , wherein two lower of the waveguide segments (12a, 12b) are arranged below the active elements (13) or below the active element (13) and the electrode and are preferably spaced from one another in the transverse direction to form a gap (14) extending between them, and a first middle one of the waveguide segments (12c) between the two active elements (13) or between the active element (13) and the electrode. is ordered, and a second central waveguide segment (12d) is arranged above the two active elements (13) or above the active element (13) and the electrode, and the two remaining, upper waveguide segments (12e, 12f) above the second central waveguide - tersegmentes (12d) are arranged, wherein the two upper waveguide segments (12e, 12f) are preferably spaced apart in the transverse direction with the formation of a gap (14) extending between them.

12. modulator (22) according to one of claims 9 to 11, characterized in that the two active elements (13) or the active element (13) and the electrode are spaced apart and offset from one another in such a way that they are in an overlap area (23) are from sections on top of each other. 13. Modulator (22) according to claim 9 or 10 and claim 12, characterized in that the overlap region (23) is above or below the gap (14).

14. modulator (22) according to claim 11 and 12, characterized in that the overlap region (23) is above the one and below the other gap (14).

15. Modulator (22) according to one of claims 9 to 14, characterized in that above the two active elements (13) or above the active element and the electrode exactly one gap (12a-12f) formed between two spaced waveguide segments ( 14) is provided and / or that exactly one gap (14) formed between two spaced waveguide segments (12a-12f) is provided below the two active elements (13) or below the active element (13) and the electrode.

16. Modulator (22) according to one of claims 9 to 15, characterized in that the extent of the overlap region (23) in the transverse direction in the range from 0.8 times to 1.8 times, preferably 1.0 times to 1.5 times the extension of the or at least one of the gaps (14) in the transverse direction.

17. Modulator (22) according to one of claims 9 to 16, characterized in that the at least one material is at least one of the active elements (13), the refractive index of which is dependent on a voltage and / or the presence of charge and / or an electrical field changes to graphene, and / or at least one dichalcogenide, in particular two-dimensional transition dichalcogenide, and / or heterostructures made of two-dimensional materials and / or germanium and / or lithium niobath 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.

18. Photodetector (3) or modulator (22) according to one of the preceding claims, characterized in that the longitudinal section (12) of the waveguide (11) is arranged on or above a planarization layer (2, 17), the preferred being the Planarization layer (2, 17) on the side on which the longitudinal section (12) of the waveguide (11) is arranged on this, at least in sections, due to a roughness in the range from 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, and / or that the longitudinal section (12) of the waveguide (11) at least partially in a planarization layer (2, 17) is embedded, and the active element (13) or one of the active elements (13) on the planarization Layer (2, 17) is arranged, the planarization layer (2, 17) preferably on the side on which the active element (13) is arranged on this, at least in sections by 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.

19. photodetector (3) or modulator (22) according to one of the preceding claims, characterized in that the longitudinal section (12) of the waveguide (11) titanium dioxide and / or aluminum nitride and / or tantalum toxide and / or silicon nitride and / or Aluminum oxide and / or silicon oxy-nitride and / or lithium niobate and / or silicon, in particular polysilicon, and / or indium phosphite and / or gallium arsenide and / or indium gallium arsenide and / or aluminum gallium arsenide and / or at least one dichalcogenide, in particular two-dimensional transition metal Dichalcogenide and / or chalcogenide glass and / or heterostructures made of two-dimensional materials and / or resins or resin-containing materials, in particular SU8, and / or polymers or materials containing polymers, in particular OrmoClad and / or OrmoCore, or consists of it.

20. A semiconductor device comprising a chip and at least one, preferably a plurality of photodetectors (3) and / or modulators (22) according to one of claims 1 to 19, wherein the photodetector or photodetectors (3) and / or modulators (22) are preferably on the Chip or are arranged on a layer arranged on the chip or above the chip.

21. The semiconductor device according to claim 20, characterized in that the photodetector (3) and / or modulator (22) is part of a photonic platform produced on the chip or bonded to the chip.

22. A semiconductor device comprising a wafer (1) and at least one, preferably a plurality of photodetectors (3) and / or modulators (22) according to one of claims 1 to 19, wherein the photodetector (s) (3) and / or modulators (22) are preferably arranged on the wafer (1) or on a layer (2) arranged on the wafer (1) or above the wafer (1).

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