Method for manufacturing an integrated optics device with a poled organic structure

Abstract

A method is described for manufacturing an integrated optics de- vice having a waveguiding arrangement (6) having an electro-optic structure with an organic material (9). The method comprises depositing, on a substrate (4), the organic material (9) and covering the organic material with a first protective coating (32). Subsequently, the organic material is poled by applying an electric field. After poling, a second protective coating (34) is deposited on the first protective coating (32). By using at least two separate protective coatings (32, 34), with at least one being depos- ited before poling the organic material (9) and at least one being deposited thereafter, the reliability of the device can be improved.

Description

[0001] Method for manufacturing an integrated optics device with a poled organic structure

[0002] Technical Field

[0003] The invention relates to a method for manufacturing an integrated optics device having a waveguiding arrangement with an electro-optic structure comprising an organic material.

[0004] Background Art

[0005] WO 2023 / 088561A1 describes an integrated-optics device of this type. It has a waveguiding arrangement comprising a plasmonic waveguide formed by an organic, electro-optic material and adjacent electrodes.

[0006] During manufacture, the organic material has to be poled in order to align its chromophores and to generate a linear electro-optic effect.

[0007] One challenge in devices of this type of type is long-term stability of its organic material. In particular, the organic material may exhibit signs of aging. For example, it may oxidize or undergo other types of undesired chemical or physical interactions with ambient materials.

[0008] Therefore, typically, a protective coating is applied over the organic material.

[0009] Disclosure of the Invention

[0010] The problem to be solved by the present invention is to improve the long-term stability of such devices.

[0011] This problem is solved by the method of claim 1.

[0012] Accordingly, the invention provides a method for manufacturing an integrated optics device having a waveguiding arrangement with an electro-optic structure. The electro-optic structure comprises an organic material exhibiting an electro-optic effect. The method comprises at least the following steps: a) Depositing, on a substrate, the organic material. b) Covering the organic material with a first protective coating. c) After step b), poling the organic material by applying an electric field to the organic material. d) After step c), depositing, on the first protective coating, a second protective coating.

[0013] Hence, according to this method, a first protective coating is deposited to cover the organic material prior to poling, and a second protective coating is deposited on the first protective coating after poling.

[0014] This sequence of steps is based on the understanding that the organic material may already suffer damage after its deposition and prior to or during poling, and this risk can be reduced by the first protective coating. On the other hand, the first protective coating may be damaged during poling, or it may be insufficient for long-term stability, for which reason the second protective coating is applied after poling.

[0015] This sequence of steps is particularly advantageous when the method comprises heating the organic material while poling it. Such heating may damage the first protective coating, but the second protective coating will re-seal the protective cover.

[0016] The invention can be used with particular benefit when a plurality of the waveguiding arrangements are formed on a wafer, whereupon the wafer is diced. Dicing produces a plurality of chips, with each chip comprising at least one waveguiding arrangement. In this case, the dicing is best carried out after step b). In other words, the first protective coating is formed before dicing, thereby protecting the organic material in the dicing process.

[0017] In this case, advantageously, dicing is carried out before step d), i.e., the second protective coating is formed after dicing, which avoids accidental damaging the second protective coating during dicing.

[0018] Dicing may even be carried out before step c), i.e., poling takes place only after dicing, which, e.g., allows to perform the electrical bonding steps prior to poling and then use the bonds or leads in the poling.

[0019] In another embodiment, though, dicing may also be carried out after step c), which allows to pole the organic material at wafer-level, or even after step d), which allows to also apply the second protective coating at wafer-level. In other words, dicing may also be carried out after step c), in particular after step d).

[0020] The second protective coating may comprise a plurality of sublayers, with adjacent sublayers being of different materials. Such a multi-layer structure provides better long-time stability of the device because it is less prone to have defects that continuously extend through all sublayers. The first protective coating does not have to provide long-term stability alone. Therefore, it may consist of less sublayers than the second protective coating. In particular, it may have only a single sublayer, i.e., it is a one-layer coating.

[0021] Atomic layer deposition is an advantageous technique for depositing the first and / or second protective coating because it provides conformal coating, good and dense material properties, and it can be deposited at low temperatures, the latter making it less likely to damage the organic material during the coating process.

[0022] The method may comprise the step of bonding electrical leads, e.g., wires, to the integrated optics device, which may later be used to operate the device. These leads may be applied prior to step c), in which case they can be used for applying a voltage to the device in order to pole the organic material in step c).

[0023] The leads may alternatively be bonded after step c), i.e., after poling. This has the advantage that no bonding is required for devices where poling failed.

[0024] The leads are advantageously connected to the device after step b) such that the first protective coating protects the organic material during the bonding process. In that case, the first protective coating may be provided with openings where the leads are applied to the integrated optics device.

[0025] The leads may also be bonded prior to step d), which obviates the need to form or provide openings in the second protective layer and avoids a risk of damaging the second protective layer in the bonding process.

[0026] In one embodiment, the method may comprise the step of bonding electrical leads to the integrated optics device after step b) and prior to step d), in particular after step c).

[0027] Brief Description of the Drawings

[0028] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein:

[0029] Fig. 1 schematically shows a simple integrated optics device having a waveguiding arrangement,

[0030] Fig. 2 shows a sectional view along line II - II of Fig. 1,

[0031] Fig. 3 shows a step during manufacturing the device after depositing the organic material on the substrate, Fig. 4 shows a step during manufacturing the device after covering the organic material with the first protective coating,

[0032] Fig. 5 shows a step during manufacturing the device during dicing of the wafer,

[0033] Fig. 6 shows a step during manufacturing the device during poling of the organic material,

[0034] Fig. 7 shows a step during manufacturing the device after depositing the second and the third protective coating,

[0035] Fig. 8 shows a sectional view of a second embodiment of a device, Fig. 9 shows a top view of a third embodiment of a device, and Fig. 10 shows a sectional view of a fourth, non-plasmonic embodiment of a device.

[0036] Note: The figures are not to scale.

[0037] Modes for Carrying Out the Invention

[0038] Definitions

[0039] A structure or material is defined to be "electro -optic" if it has a linear electro-optic effect (i.e., its refractive index exhibits a linear dependency component on an applied electric field) or if it exhibits second order nonlinear-optical properties, i.e., if it exhibits three-wave mixing. Both these effects are only present in non- centro symmetric materials.

[0040] The "vertical" direction is defined to be perpendicular to the substrate of the device, with the waveguiding arrangement 6 being located "on top" or "above" the substrate. The top side of the substrate is the side facing the waveguiding arrangement. Any "horizontal" direction extends perpendicularly to the vertical direction. The term "lateral" indicates an offset along the horizontal direction.

[0041] Basic device design

[0042] A simplified design of an embodiment of an integrated optics device is shown in Figs. 1 and 2. The device is formed by a chip 2 having a substrate 4 and a waveguiding arrangement 6 arranged on substrate 4. The waveguiding arrangement 6 comprises an electro-optic structure 8 of an organic material 9.

[0043] In the shown embodiment, the waveguiding arrangement 6 comprises a plasmonic waveguide 10 formed at the interfaces between the organic material 8 and one or two electrodes 12a, 12b, with the electrodes 12a, 12b being conductors. The waveguiding arrangement 6 may further comprise waveguiding elements 14a, 14b connecting plasmonic waveguide 10 to couplers 16a, 16b for coupling light in and out of the device. The couplers 16a, 16b may, e.g., be grating couplers or edge couplers. The waveguiding elements 14a, 14b comprise tapered sections 18a, 18b that couple them to plasmonic waveguide 10 as, e.g., described in section 4.1.2 of W. Heni, "Plasmonic-Organic Hybrid Modulators", https: / / doi.org / 10.3929 / ethz-b- 000353598.

[0044] The electrodes 12a, 12b and plasmonic waveguide 10 together form the electro-optic structure 8 of the device.

[0045] The electrodes 12a, 12b are connected to contact pads 20, e.g., by means of electrical connectors 22. Electrical leads 24, in particular wires or ribbons, are connected to the contact pads 20.

[0046] The device of Figs. 1 and 2 can, e.g., be used for modulating the phase of the light passing through waveguiding arrangement 6 by means of a voltage applied to the electrodes 12a, 12b via the leads or wires 24.

[0047] Substrate 4 may be of any suitable material. Advantageously, though, it is made of a dielectric at least at its top surface 26 where it faces the waveguiding arrangement 6.

[0048] In the shown embodiment, substrate 4 has a silicon carrier 28 with a dielectric top layer 30 forming top surface 26. Top layer 30 may, e.g., be of silicon dioxide. However, substrate 4 may, e.g., also be a glass substrate.

[0049] As mentioned above, organic material 8 needs to be protected by protective coatings. The shown embodiment has three types of protective coatings:

[0050] - A first protective coating 32 is arranged on top of organic material 9. It encloses organic material 9 at least from above and, if necessary, also laterally, such that organic material 9 is hermetically sealed, e.g., between protective coating 32 and substrate 4. First protective coating 32 horizontally extends, on all sides at least over the whole area of organic material 9. It advantageously extends horizontally over all of the chip 2 of the device, in which case, however, it should have openings at the location of the contact pads 20 and, optionally, at the locations of the optical couplers 16a, 16b, and / or it might be removed in other areas, e.g., in the area where the dicing will occur.

[0051] - A second protective coating 34 is arranged on top of first protective coating 32. It advantageously extends in all lateral directions at least over the whole area of organic material 9. It may extend horizontally over all of chip 2, in which case, however, it may have openings at the location of the contact pads 20 and, optionally, at the locations of the optical couplers 16a, 16b, and / or it may be removed in other areas, e.g., in the area where the dicing will occur.

[0052] - A third (optional) protective coating 36 is arranged on top of second protective coating 34. It advantageously extends on all sides at least over the whole area of organic material 9. In the present embodiment, it extends only over part of chip 2 and not to all of the edges of the chip 2 of the device, in particular not to any of the edges of the chip 2.

[0053] As mentioned, the method may comprise the step of dicing the wafer along dicing regions, which are the "areas where the dicing will occur" as mentioned above. In this case, also as mentioned, in one aspect, none of the first and / or second protective coating should be present at said dicing regions. This reduces the risk of structurally damaging the coatings during the dicing process.

[0054] Manufacturing steps

[0055] In the following, the steps for manufacturing the device of Figs. 1 and 2 are described in reference to Figs. 3 - 7. It must be noted, though, that the same steps can also be used to manufacture devices with different geometries, such as the devices described in subsequent sections.

[0056] In a first step, which may occur after earlier manufacturing steps, e.g., steps at the FEOL ("Front End Of Line") level, the electrodes 12a, 12b as well as the conductors 22 and contact pads 24 are formed on substrate 4, optionally together with any further BEOL ("Back End of Line") structures of the device. This may occur at the wafer-level, i.e., substrate 4 forms part of a larger wafer, on which the first step is carried out for several devices at the same time. Note that, in the present context, the term "wafer" may designate the whole, typically circular wafer, or a smaller entity that has, e.g., been cut into rectangular size but still contains several future devices and needs to be diced at a later step.

[0057] This first step may, e.g., be carried out at a semiconductor foundry using techniques and materials that are used in conventional semiconductor manufacturing processes.

[0058] The electrodes 12a, 12b may be of gold, which is particularly suited for forming a low-loss plasmonic waveguide. But they may also be of another metal, such as silver, or they may be of a doped semiconductor. The semiconductor may be doped to form a plasmonic waveguide together with the organic material 9 and / or for electrical conductivity. The conductors 22 may, for example, be of aluminum as it is typically used for conducting leads in BEOL structures, but they may also be of another metal, such as tungsten, or they may be formed by suitably doped semiconductor.

[0059] After depositing the electrodes 12a, 12b and the conductors 22, the organic material 9 is deposited on the wafer, as shown in Fig. 3. This step may be carried out outside a standard foundry process.

[0060] In the shown embodiment, organic material 9 at least fills the gap 38 between the electrodes 12a, 12b.

[0061] Advantageously, organic material 9 is only deposited locally, i.e., using a local ink-jet printing process, an aerosol printing process, a drop-casting process, or a dispensing process. Alternatively or in addition thereto, organic material 9 may be structured only after its deposition, e.g., using spin-coating followed by etching or lift-off.

[0062] In the shown embodiment, organic material 9 laterally extends over the electrodes 12a, 12b at least along the direction X extending perpendicularly to the elongate direction of gap 38. It may even extend, as shown, laterally over the conductors 22a, 22b, at least in the direction X.

[0063] Organic material 9 may comprise an organic dye, organic electrooptic polymers, chromophores, or composite materials thereof. In particular, it may include at least one of the following compounds: disperse red 1 (DR1), SEO 100, SEO125, SEO250, GigOptixM3, JRD1, YLD124, HLD, AJCKL1, Perkinamine. It may also include any of these compounds in a host material, such as poly methyl methacrylate (PMMA), such as DR1 in PMMA or amorphous polycarbonate (APC), e.g., AJCKL1 in APC.

[0064] Once that organic material 9 has been deposited, it is covered with first protective coating 32 as shown in Fig. 4.

[0065] Advantageously, the deposition of first protective coating 32 is carried out at with a low-temperature process, in particular in a process having a maximum temperature below 120 °C, in particular below 80 °C. Using such a low-temperature process reduces the risk of damaging organic material 9.

[0066] Protective coating 32 is advantageously of AI2O3 since this material does not negatively interact with the organic material 9 and can be deposited in using atomic layer deposition (ALD) process at fairly low temperatures, in particular at temperatures below 80 °C. Other materials with similar properties, e.g., include ZnO, SiO2, HfO2, ZrO2, ZnO, SiN, silicon oxynitride, TiO2, or TiN.

[0067] Instead of ALD, other low-temperature deposition techniques, such as sputtering, physical vapor deposition, or chemical vapor deposition, may be used as well. Suitable materials are, e.g., SiCh, Silicon Nitride, Parylene, AI2O3, TiCE, Titanium Nitride

[0068] First protective coating 32 may consist of a single material layer only, i.e., it does not consist of several sublayers. It needs to provide temporary protection only, and therefore its tightness needs not be as good as the one of second protective coating 34 as described below.

[0069] The thickness of first protective coating 32 is advantageously between 25 and 150 nm.

[0070] First protective coating 32 is advantageously deposited over the whole of chip 2, and structuring techniques such as etching, lift-off, or laser ablation (as described in the next section) is subsequently used to remove it from the contact pads 20. It may also be removed from the optical couplers 16a, 16b, but it may also be left there if it is transmissive for the wavelength of the light to be used. It may also be removed in other areas, e.g. in the area where the dicing will occurs, for the reasons mentioned above.

[0071] After depositing first protective coating 32, further process steps can be applied without major risk of damaging organic material 9.

[0072] In the example shown here, the steps described so far have been carried out on wafer-level, and the wafer may now be diced to form the individual chips 2, as illustrated in Fig. 5. Each chip 2 may comprises only of a single device, e.g., with only one or two or four waveguiding arrangements, or several devices.

[0073] Next, as illustrated in Fig. 6, organic material 9 has to be poled in order to align its chromophores at least partially in order to obtain a linear electro -optic effect. To do so, a poling voltage V has to be applied over the electrodes 12a, 12b

[0074] Hence, in more general words, the electrodes 12a, 12b are formed on substrate 4 prior to depositing first protective layer 32, and a voltage is applied over the electrodes 12a, 12b for poling the organic material.

[0075] Before poling, the leads 24 (see Fig. 1) may be bonded to the contact pads 20, which allows to use the leads 24 for applying the poling voltage V. Alternatively, contact needles may be applied to the device for poling. The step of bonding the leads 24 to the pads 20 advantageously takes place after depositing first protective coating 32 in order to reduce the risk of damaging organic material 9.

[0076] Poling advantageously takes place at an elevated temperature, advantageously near the glass transition temperature of the organic material, in order to mobilize the chromophores of the material. For example, the temperature in the poling step is at least 90°C, in particular at least 120°C. A lower temperature for poling may, e.g., be required when subsequently cross-linking the organic material to raise its glass transition temperature.

[0077] Suitable poling processes are, e.g., described W. Heni, "Plasmonic- Organic Hybrid Modulators", https: / / doi.org / 10.3929 / ethz-b-000353598.

[0078] Next, unless bonding has already taken place, the integrated optics device may be bonded to the leads 24.

[0079] Next, a second protective coating 34 is deposited on first protective coating 32. This step greatly increases the durability of the device in case first protective coating 32 is damaged during poling, e.g., due to the high temperatures in the poling step and / or due to a deformation of organic material 9 during poling or (if used) cross-linking.

[0080] Advantageously, second protective coating 34 is deposited at a temperature lower than the maximum temperature used in the poling process. This reduces the risk of partial or complete depolarization of organic material 9 while depositing second protective coating 34.

[0081] Advantageously, the maximum temperature during depositing second protective coating 34 is at least 40 °C lower than the maximum temperature during poling.

[0082] In absolute terms, the maximum temperature during depositing second protective coating 34 is advantageously below 120°C, in particular below 80 °C.

[0083] Second protective coating 34 may, e.g., comprise one or more of the same materials as listed above for first protective coating 32.

[0084] Again, atomic layer deposition may advantageously be used. However, other techniques, such as the ones mentioned above for first protective coating 32, or molecular layer deposition for the deposition of organic layers, may be used as well.

[0085] As mentioned, second protective coating 34 may comprise a plurality of sublayers 34-1, 34-2... (see Fig. 2), with adjacent sublayers being of different materials, for better long-time stability of the device.

[0086] The sublayers may, e.g., be alternatingly of AI2O3 and ZnO. Other suitable materials, e.g., include TiO2 and / or ZrO2.

[0087] Advantageously, each of the sublayers has a thickness between 1 and 100 nm, in particular between 2 and 20 nm. The number of sublayers for a multiple-sublayer coating is at least two, but there may be more sublayers, in particular at least 8. The total thickness of second protective coating 34 is advantageously between 50 and 200 nm. Thicker coatings are better, but depositing them takes more time.

[0088] In a further, optional step, a third protective coating 36 may be deposited on second protective coating 34. Third protective coating 36 may be of a material different from second protective coating 34 and be optimized to withstand other contaminants and / or physical impact.

[0089] Third protective coating 36 may have a thickness larger than second protective coating 34 to provide additional mechanical and chemical protection. Advantageously, its thickness is at least 0.5 m or at least 1 pm.

[0090] Advantageously, third protective coating 36 is applied by means of a deposition process different from the one of second protective coating 34, which allows to optimize its structure and properties.

[0091] In particular, third protective coating 36 may comprise, upon depositing, materials that could damage organic material 9 if it were applied directly on organic material 9. Such materials are prevented from reaching organic material 9 by second protective coating 34. Therefore, the step of applying third protective coating 36 may include applying the third protective coating with a solvent that would damage the organic material 9 and using second protective coating 34 as a barrier for preventing the solvent from reaching organic material 9.

[0092] Third protective coating 36 may advantageously be deposited as a monomer or polymer precursor that is polymerized after deposition. In particular or alternatively, it may be deposited as an organic or inorganic materials, such as an epoxy-based compound, a silicone-based compound, a silazane -based compound, or an acrylate-based compound that is hardened after deposition. Further materials are known in the field and include adhesives, sol-gel materials, silicones, siloxanes, silicates. The third protective coating might be cured or hardened after deposition, e.g., by radiation, in particular UV, by temperature, or by humidity. Suitable materials are commercially available.

[0093] Alternatively, protective coating 36 may be deposited as an organic compound comprising a solvent to be evaporated.

[0094] As shown in Figs. 1, 2, and 7, third protective coating 36 is best deposited only over part of the device, i.e., it is deposited in a local deposition process. It particular, it is advantageously not deposited on any contact pads 20 and / or optical couplers 16a, 16b of the device in order to obviate the need for a subsequent lift-off or etching step to make these areas available for contacting. Laser ablation

[0095] As mentioned above, laser ablation may be used to locally remove part of the protective coatings 32, 34, 36 or other layers of the device.

[0096] To do so, the parts to be removed are irradiated by laser radiation for evaporation and / or decomposition. In particular, at least one of the protective coatings 32, 34 may be locally removed in this way, e.g., at the locations where bonding with the leads 24 is to take place.

[0097] Laser ablation has the advantage that it generates only a small amount of thermal and mechanical stress outside the region of ablation, thereby reducing the risk of damaging device structures, in particular of damaging any protective coating in places where it need not be removed. Also, laser ablation can be controlled accurately and flexibly.

[0098] Advantageously, the device is placed on a translation stage in order to position the laser spot at the site of ablation. The translation stage might feature an precision of smaller than <10 pm. Alternatively or additionally, a beam deflector is used to position a laser spot at the site of ablation. The beam deflector may e.g., include one or more actuatable reflectors and or actuators operating on a laser source and / or on lenses processing the beam from a laser source.

[0099] Properly positioning the ablation process may be supported by first detecting, e.g., by means of a camera, the position of the integrated optics device to be processed, whereupon the beam deflector or the translation stage is controlled to position the position of the device relative to the laser spot.

[0100] Advantageously, a pulsed laser source is used with pulses in the nanosecond range or shorter.

[0101] Advantageously, laser radiation with a wavelength of below 450 nm is used, which is absorbed by the protective coatings 32, 34 as described herein but absorption in the metal layer in the contact regions beneath it is reduced, thereby reducing the risk of damage of the metal layer.

[0102] Hence, the present method may comprise the step of locally removing at least one of the protective coatings by means of laser ablation.

[0103] In particular, the method may comprise the steps of

[0104] - detecting a position of the integrated optics device to be processed, and

[0105] - controlling the position of a laser spot relative to the detected position of the integrated optics device.

[0106] Laser ablation may, in particular, take place after dicing the wafer because it provides an efficient way to process individual integrated optics devices. Advanced device design

[0107] The device design shown in Figs. 1 - 7 serves to illustrate the processing steps, but real-world devices may be more complex.

[0108] For example, a multi-layer BEOL structure can be used to implement more complex device geometries. In particular, and as shown in Fig. 8, a plurality of metal and oxide layers may be deposited on top of substrate 4, at the foundry, prior to depositing organic material 9. In this example, an additional dielectric layer 40 (e.g., SiOi) and metal layer 42 are deposited on substrate 4 for electrically interconnecting the components on the device.

[0109] Other complex device geometries are, for example, described in WO 2023 / 088561A1.

[0110] Fig. 9 illustrates, as an example, an interferometer-type modulator using the present technique. It comprises three electrodes 12a, 12b, 12c forming two plasmonic waveguides 10a, 10b in gaps between them and, further, a thermo-optic phase shifter 44 for tuning the interferometer. Details of the operation of such a device are provided in WO 2023 / 088561.

[0111] In this example, the first and second protective coatings extend over the complete device with the exception of the contact pads 20 and the optical couplers 16a, 16b. Organic material 9 and third protective coating 36, however, are only locally deposited in the region of the electrodes 12a, 12b, 12c and do not reach the edges of chip 2 of the device.

[0112] Non-plasmonic waveguiding arrangements

[0113] The examples above show waveguiding arrangements with plasmonic waveguides. The present invention, however, can also be used for devices with waveguiding arrangements that are not plasmonic. For example, such waveguiding arrangements may include at least one dielectric or semiconductor waveguide, such as a silicon waveguide, silicon nitride waveguide, or a glass waveguide, with the organic material being adjacent to the waveguide such that the light guided by the waveguide extends, to a substantial degree, into the organic material. Electrodes positioned to generate a field in the organic material may be used for poling the organic material when manufacturing the device and for phase modulation in operation of the device.

[0114] Fig. 10 shows an embodiment of such a device. Here, instead of using separate electrodes, two silicon waveguides 50a, 50b may be doped or partially doped to be electrically conductive, in which case they not only serve to guide light but also to generate an electrical field in a gap 38 between them, with the gap 38 being filled with the organic material 9. If the width of gap 38 is narrow enough (in the order of a wavelength or less), the two silicon waveguides 50a, 50b form, a single non-plasmonic waveguide 10', otherwise, the form two separate non-plasmonic waveguides 10'. On both cases, though, at least part of the guided light extends into the organic material 9.

[0115] Hence, in one embodiment, the waveguiding arrangement 6 forms a non-plasmonic waveguide 10', in particular a non-plasmonic waveguide 10' where at least part of the guided light extends into the organic material 9.

[0116] In another embodiment, the waveguiding arrangement 6 forms a plasmonic waveguide 10, in particular a plasmonic waveguide 10 where at least part of the guided light extends into the organic material 9.

[0117] Notes

[0118] In the examples above, the wafer was diced after applying first protective coating 32. Alternatively, though, poling and, optionally, the deposition of second protective coating may be carried out at the wafer level, with dicing only taking place after that.

[0119] As mentioned, third protective coating 36 is optional, in particular if the final device is packaged in a tight protective casing.

[0120] Advantageously, the first and second protective coatings 32, 34 are dielectric materials in order to reduce effects on the electrical field in organic material 9.

[0121] In general terms, the present invention relates to a method for manufacturing an integrated optics device having a waveguiding arrangement 6 with an electro-optic structure comprising an organic material 9. The method comprises depositing, on a substrate 4, the organic material 9 and covering the organic material 9 with a first protective coating 32. Subsequently, the organic material 9 is poled by applying an electric field. After poling, a second protective coating 34 is deposited on the first protective coating 32. By using at least two separate protective coatings 32, 34, with at least one being deposited before poling the organic material 9 and at least one being deposited thereafter, the reliability of the device can be improved.

[0122] While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

Claims

Claims1. A method for manufacturing an integrated optics device having a waveguiding arrangement (6) with an electro-optic structure comprising an organic material (9), comprising the steps of a) depositing, on a substrate (4), the organic material (9), b) covering the organic material (9) with a first protective coating (32), c) after step b), poling the organic material (9) by applying an electric field to the organic material (9), and d) after step c), depositing, on the first protective coating (32), a second protective coating (34).

2. The method of claim 1 comprising the step of heating the organic material (9) while poling it.

3. The method of claim 2 wherein step d) is carried out at a lower temperature than step c).

4. The method of any of the claims 2 or 3 wherein a temperature in step c) is at least 90°C, in particular at least 120 °C.

5. The method of any of the preceding claims wherein a maximum temperature in step d) is by at least 40 °C lower than a maximum temperature in step c).

6. The method of any of the claims wherein a maximum temperature in at least one of step b) and step d) is below 120 °C, in particular below 80 °C.

7. The method of any of the preceding claims further comprising the steps of forming a plurality of the waveguiding arrangements (6) on a wafer and dicing the wafer to form a plurality of chips (2), with each chip (2) comprising at least one waveguiding arrangement (6), wherein the dicing is carried after step b).

8. The method of claim 7 wherein the dicing is carried out before step d).

9. The method of any of the claims 7 or 8 wherein the dicing is carried out before step c).

10. The method of claim 7 wherein the dicing is carried out after step c), in particular after step d).

11. The method of any of the claims 7 to 10 comprising the step of dicing the wafer along dicing regions wherein none of the first and / or second protective coating is present at the dicing regions.

12. The method of any of the preceding claims comprising the step of depositing, on the second protective coating (34), a third protective coating (36), wherein the third protective coating (36) has a thickness larger than the second protective coating (34) and is of a material different from the second protective coating (34).

13. The method of claim 12 wherein the third protective coating (36) is deposited as at least one of an epoxy-based compound, a silicone-based compound, a silazane-based compound, and an acrylate-based compound that is hardened after deposition.

14. The method of any of the claims 12 or 13 wherein the third protective coating (36) is deposited only over part of the device, and in particular wherein it does not extend to all of the edges of a chip (2) of the device, and in particular wherein it does not extend to any of the edges of a chip (2) of the device.

15. The method of any of the preceding claims wherein the second protective coating (34) comprises a plurality of sublayers (34-1, 34-2...), wherein adjacent sublayers (34-1, 34-2...) are of different materials.

16. The method of any of the preceding claims wherein the first protective coating (32) consists of less sublayers than the second protective coating (34).

17. The method of any of the preceding claims further comprising the steps offorming electrodes (12a, 12b) on the substrate (4) prior to step b) and applying a voltage over said electrodes (12a, 12b) for poling the organic material (9) in step c).

18. The method of any of the preceding claims wherein said first and / or said second protective coating (32, 34), in particular both of them, are deposited by means atomic layer deposition.

19. The method of any of the preceding claims comprising the step of bonding electrical leads (24) to the integrated optics device after step b) and prior to step d), in particular after step c).

20. The method of any of the preceding claims wherein the waveguiding arrangement (6) forms a plasmonic waveguide (10).

21. The method of any of the claims 1 to 19 wherein the waveguiding arrangement (6) forms a non-plasmonic waveguide (10')-22. The method of any of the preceding claims further comprising the step of locally removing at least one of the protective coatings by means of laser ablation.

23. The method of claim 22 comprising the steps of- detecting a position of the integrated optics device to be processed, and- controlling a position of a laser spot relative to the position of the integrated optics device.

24. The method of any of the claims 22 or 23 wherein laser ablation takes place with laser light in a wavelength below 450 nm.

25. The method of claim 7 and of any of the claims 22 to 24 wherein laser ablation takes place after dicing.

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