Controlled Deposition of Functional Materials onto Target Surfaces

Abstract

Wavelength (λ R3 Provided herein is a plate (1) including a functional material (2) to be deposited onto a target surface (51) using monochromatic photon radiation (R3) having a wavelength of 1000 nm. The plate includes a substrate (10) having a first surface (11) facing the target surface and a second surface (12) for receiving the monochromatic photon radiation. The first surface (11) is patterned with one or more recessed areas (111) having a dielectric coating (4) and filled with the functional material. The dielectric coating (4) includes a series of dielectric coating layers (41, 42, 43) with alternating refractive indices. The dielectric coating (4) thereby has a relatively high reflectivity for the monochromatic radiation (R3) incident normally to the dielectric coating (4) compared to the reflectivity for the monochromatic radiation (R3) incident at a 45-degree angle to the dielectric coating (4). This reduces shear forces without requiring high alignment accuracy. The present application also provides a deposition device including the plate, and a method including the plate.

Description

[Technical field]

[0001] The present application relates to a method for the controlled deposition of a functional material onto a target surface.

[0002] The present application further relates to a plate comprising a functional material deposited onto a target surface.

[0003] The present application further relates to a deposition device including such a plate. [Background technology]

[0004] According to one approach, the deposited functional material is provided as a continuous layer on a first side of a substrate, and the layer is locally removed by a laser beam directed through the substrate onto the layer, examples of which are US2009 / 061112A1, EP2924718A1, EP2843079A1, US6177151B1.

[0005] According to another approach, the deposited functional material is not present as a continuous layer, but in recessed areas of the source substrate. A method for controlled deposition of functional material on a target surface according to this approach is known from US2017268100. According to the method disclosed therein, an optically transparent plate is provided having a first side with one or more wells and a second side opposite the first side. After coating the first side with a thin layer of light absorbing material, the wells are filled with functional material. The plate is then irradiated from the second side with pulsed light to generate gas to transfer the functional material from the wells onto a receiving substrate arranged adjacent to the plate, resulting in heat in the wells. In this process, the heat flux around the wells determines how the functional material is ejected.

[0006] As shown diagrammatically in FIG. 1, a typical sidewall of a well 111 is inclined with respect to the normal of the plate. As shown in FIG. 1A, the calculated light power density (heat flux) on the plane of the sidewall is thereby proportional to the cosine of the angle of the sidewall with respect to the bottom of the well. Thus, in known methods, when a focused or collimated laser beam illuminates the well from the second side, the sidewall of the well will have a lower power density due to the larger angle of incidence. For example, when the sidewall is inclined at an angle of 70° with respect to the bottom, the power density, and therewith the heat flux, on the plane of the sidewall will be almost three times lower compared to the power density on the bottom of the well. This means that the heat introduction on the sidewall of the well is significantly less than on the bottom of the well. As a result, the pressure applied to the functional material has a substantially inhomogeneous distribution, which results in the functional material being subjected to significant shear forces during the transfer process, especially when using highly viscous functional materials. Beam shaping is an option to control the heat flux on the sidewalls, but it becomes significantly more difficult with small spot sizes. Also, aligning a shaped beam on a small well would require a highly accurate system. This approach becomes even more complicated if the wells are of different sizes and shapes. In that case, it becomes necessary to dynamically adapt the beam shape to the targeted well shape. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2009 / 061112 (US2009 / 061112A1) [Patent Document 2] European Patent Application Publication No. 2924718 (EP2924718A1) [Patent Document 3] European Patent Application Publication No. 2843079 (EP2843079A1) [Patent Document 4] U.S. Patent No. 6,177,151 (US6,177,151B1) [Patent Document 5] US Patent Application Publication No. 2017268100 (US2017268100) Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present application to provide an improved method in which shear forces are reduced without the need for high alignment accuracy. Accordingly, a method is provided as claimed in claim 1.

[0009] It is a further object of the present application to provide an improved plate for use in the improved method. Accordingly, a plate is provided as claimed in claim 8.

[0010] It is yet a further object of the present application to provide an improved deposition device in which shear forces are reduced without the need for high alignment accuracy. Accordingly, a deposition device is provided as claimed in claim 15. [Means for solving the problem]

[0011] An improved method for controlled deposition of a functional material onto a target surface using monochromatic radiation having a wavelength as claimed in claim 1 comprises the following steps:

[0012] A transparent carrier plate is provided having a substrate with first and second mutually opposing surfaces. The first surface of the substrate is provided with one or more recessed areas. The substrate may be provided of any transparent material, for example glass or silicon oxide, and the one or more recessed areas may be provided therein in any manner, for example by etching.

[0013] A dielectric coating is deposited on the first surface. Therewith, in a subsequent step, a number of dielectric coating layers are deposited, each subsequent dielectric coating layer having a refractive index different from that of the previous dielectric coating layer. That is, in this stage, alternating dielectric coating layers with relatively low and relatively high refractive indices are deposited. The dielectric coating layers are deposited in a conformal manner on the first surface of the substrate with one or more recessed areas, so that the thickness of the dielectric coating layer measured locally in a direction perpendicular to the surface is substantially uniform. For practical purposes, the dielectric coating is deposited over the entire first surface. However, this is not essential. It is sufficient if the dielectric coating is present on the first surface inside the one or more wells, including their bottoms and sidewalls. Typically, chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques are used to deposit these thin layers with well-defined thicknesses that are conformal with the surface.

[0014] The dielectric layer has a thickness in a range in which the dielectric coating has a relatively high reflectance for the monochromatic radiation incident perpendicularly to the dielectric coating compared to the reflectance for the monochromatic radiation incident at an angle of 45 degrees to the dielectric coating. In one embodiment, the dielectric coating layer has a thickness in the range of 0.05 to 0.15 times the wavelength of the monochromatic photon radiation, thereby reducing the risk of damage due to thermal stress. For this purpose, it is also preferred that the absorption of the monochromatic radiation in the dielectric coating is as low as possible, for example less than 10%, more preferably less than 5%, even more preferably less than 2%.

[0015] The recessed area or areas are then filled with a functional material. The filling can be performed immediately after the deposition of the dielectric coating, but alternatively, other process steps may be performed in between. For example, the dielectric coating can be realized with a protective layer, for example a scratch-resistant layer.

[0016] In use, the transparent carrier plate is positioned between a monochromatic radiation source and a target surface of a target, whereby the plate faces the target surface with its first surface.

[0017] Monochromatic radiation is then directed at the second surface of the plate. The monochromatic radiation has an intensity and duration that transfers the functional material from the recessed area or areas to the target surface. The monochromatic radiation entering the bottom of the well transfers the dielectric coating at least substantially in a vertical direction, whereby its intensity is reduced due to the relatively high reflectivity of the dielectric coating for the monochromatic radiation in this direction. The monochromatic radiation entering the sidewall of the well transfers the dielectric coating at an angle that is substantially off from the at least substantially vertical direction. The dielectric coating is less reflective for the monochromatic radiation incident at this deviation angle, so that a larger proportion of it is transmitted through the coating. A more homogeneous distribution of the heat flux is thereby obtained, whereby the shear forces acting on the transferred and deposited functional material are reduced.

[0018] In the absence of shear forces, the functional material can be transferred with a very high viscosity. This has the advantage that the functional material does not spread on impact and high-resolution structures with high aspect ratios are possible. This also allows the transfer process to take place over a larger distance between the first and target surfaces of the plate. The larger transfer gap makes the technique easier to implement, since the tolerances for the machines are less strict. Furthermore, a large transfer gap makes it easier to print on non-flat surfaces, e.g. rough or 3D surfaces. Thereby, the technique is also suitable for 3D printing of electrical interconnects. By way of example, the viscosity is in the range of 100-1000 Pa·s.

[0019] It is sufficient that the beam of monochromatic radiation is substantially uniform in the environment of the well. Thereby, it is not necessary for the beam to be precisely shaped and aligned with the walls according to the recessed area. In some embodiments, the source of monochromatic radiation is an excimer laser. In other embodiments, the source of monochromatic radiation is a scanning laser. In some of these other embodiments, the monochromatic photon radiation is directed to the second side of the plate through a telecentric lens, ensuring that the angle of incidence is equal over the area covered by the monochromatic radiation. It should be noted that a substantially uniform exposure with monochromatic radiation is achieved if the monochromatic radiation is scanned at a substantially constant speed in the scanning direction and the integral of the beam intensity in the scanning direction is substantially constant in the direction transverse to the scanning direction within the area of ​​the well. Typically, the monochromatic radiation is provided as a large area spot with an excimer laser to irradiate the entire pattern at the same time. Thereby, for example, a 1x1 to 10x10 mm (larger than the entire pattern itself) can be obtained. 2 No scanning is required to transfer a high resolution interconnect pattern at one time using a laser spot size of 100 nm. In this case, no pulse overlap is required.

[0020] In some embodiments, the photon radiation absorbing layer is deposited after the step of depositing the dielectric coating and before the step of filling one or more recessed areas with a functional material. Thereby, a very efficient conversion of monochromatic photon radiation transmitted through the dielectric coating into heat is achieved. This is particularly useful when the deposited functional material has a relatively high reflectance or transmittance for monochromatic photon radiation. In some of these embodiments, the material of the photon radiation absorbing layer evaporates upon absorbing monochromatic photon radiation, thereby contributing to or generating a vapor pressure for releasing the functional material from the recessed area. In other embodiments, a dedicated material that evaporates may be provided in the recessed area.

[0021] In some embodiments, the non-recessed portion of the first side of the plate comprises a reflective coating that substantially reflects monochromatic radiation. Thereby, it is achieved that when the monochromatic photon radiation beam extends beyond the boundary of the recessed area, the functional material (if any) present outside the recessed area is not inadvertently deposited on the target surface. The functional material may accidentally be present outside the recessed area as a leftover. Also, it may be desirable for the entire first side of the plate to comprise the functional material in order to simplify the manufacturing process of the plate. In terms of producing a printing plate with increased reflectivity outside the recessed area, a different mirror stack is required compared to the one inside the recessed area. The simplest way to achieve this is to apply a coating with one or more coating layers before the recessed area is formed in the plate, so that no alignment is required during manufacturing. The applied coating must increase the reflectivity after the dielectric coating is deposited, i.e. provide a homogenous distribution of heat flux over the inner wall of the recessed area.

[0022] As will be apparent from above, an improved plate suitable for the improved deposition process includes a functional material that is deposited on a target surface using monochromatic photon radiation having a wavelength. The improved plate comprises a substrate having a first surface directed toward the target surface and a second surface receiving the monochromatic photon radiation. The first surface of the plate is patterned with one or more recessed areas having a dielectric coating and filled with the functional material, the dielectric coating comprising a series of dielectric coating layers with alternating refractive indices. The dielectric coating has a relatively high reflectivity for said monochromatic radiation that is perpendicularly incident on the dielectric coating compared to the reflectivity for said monochromatic radiation that is incident at a 45 degree angle to the dielectric coating. As mentioned above, it is sufficient that the dielectric coating extends beyond the portion of the first surface defined by the bottom and sidewalls of the recessed areas, but the dielectric coating may extend further outside the recessed areas, for example covering the entire first surface area of ​​the plate.

[0023] In embodiments, the plate comprises a grayscale mask on its second surface to control the heat flux of the monochromatic photon radiation. In some examples of these embodiments, the grayscale mask cooperates with the dielectric coating on the second surface of the plate to achieve at least a substantially homogeneous transmitted heat flux on the inner surface of one or more recessed areas. In this way, additional degrees of freedom are available to control the transmitted heat flux. For example, on a larger scale, the grayscale mask can be used to control the release time (different heat flux) of a pattern. For example, when transferring a line, the grayscale mask can be used to achieve an increase or decrease in heat flux at the end of the line to control how the functional material drains.

[0024] In other examples of these embodiments, the greyscale mask is provided to suppress the transmission of said radiation outside these areas. In yet other examples of these embodiments, the greyscale mask combines these functionalities. The greyscale mask can control the heat flux by absorbing and / or reflecting the radiation according to a spatial pattern. It is noted that other embodiments are conceivable in which the greyscale mask is provided as a separate element, i.e. positioned between the radiation source and the plate. However, having the greyscale mask integrated with the plate is advantageous in that a separate positioning and alignment step is thereby avoided.

[0025] Integrating the grayscale mask with the plate has the further advantage that it allows for control of the heat flux at a finer level of detail, e.g., resolution of less than 10 microns. For very precise additional heat flux control using a grayscale mask, it may be desirable to provide the grayscale mask on the same side of the dielectric coating and the substrate, e.g., between the substrate and the dielectric coating.

[0026] The improved deposition device includes the following elements in addition to the improved plate:

[0027] a holder for holding the target with a target surface facing the first surface of the plate, the target surface being to receive the functional material;

[0028] A monochromatic photon radiation source is provided for rendering monochromatic photon radiation directed towards the second surface of the plate.

[0029] The controller will cause the monochromatic photon radiation source to render monochromatic photon radiation at an intensity and duration that transfers the functional material from the recessed area or areas to the target surface.

[0030] In some embodiments, the monochromatic photon radiation source is an excimer laser that generates a beam with a uniform intensity distribution. In other embodiments, a scanning laser is used to generate the monochromatic radiation. In some of these other embodiments, the monochromatic radiation is directed to the second side of the plate through a telecentric lens to ensure that the angle of incidence is equal over the area covered by the monochromatic radiation. In one embodiment, the controller is further configured to control the movement of the scanning path of the scanning laser. Alternatively or additionally, the controller can control the position of a holder for carrying the target.

[0031] These and other aspects will be described in more detail with reference to the drawings. [Brief description of the drawings]

[0032] [Figure 1] 1A-1D show schematic diagrams of stages during a prior art deposition process. [Figure 1A] 1A-1D show schematic diagrams of stages during a prior art deposition process. [Diagram 2] FIG. 1 illustrates an embodiment of a deposition device including a plate as claimed herein. [Figure 3A] FIG. 1 illustrates an embodiment of a plate. [Figure 3B] FIG. 1 illustrates an embodiment of a plate. [Figure 4]FIG. 4 shows a schematic representation of the normalized transmitted heat flux as a function of the wall angle for a first embodiment of a plate. [Diagram 5] FIG. 10 shows a schematic representation of the normalized transmitted heat flux as a function of wall angle for a second embodiment of the plate. [Figure 6] FIG. 2 shows another embodiment of a deposition device including a plate as claimed in this specification. [Figure 7] FIG. 1 illustrates an embodiment of the method claimed herein. [Figure 8] FIG. 2 illustrates a schematic diagram of an exemplary embodiment of a method. [Figure 9A] 1A-1C show alternative embodiments of the plate claimed herein. [Figure 9B] 1A-1C show alternative embodiments of the plate claimed herein. [Figure 9C] 1A-1C show alternative embodiments of the plate claimed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Figure 2 shows the wavelength λ R3 2 shows diagrammatically a deposition device for controllably depositing a functional material 2 onto a target surface 51 of a target 5 using monochromatic radiation R3 having a wavelength of 1000 nm to 1500 nm. The deposition device of FIG. 2 comprises a carrier plate 1, a holder 7 for holding the target 5, a monochromatic photon radiation source 3, and a controller 8 for controlling the monochromatic radiation source 3.

[0034] As shown diagrammatically in FIG. 2, the carrier plate 1 has a substrate 10 with a first surface 11 directed towards the target surface 51 and a second surface 12 for receiving monochromatic photon radiation R3. The first surface 11 is patterned with one or more recessed areas 111. In the example of FIG. 2, only one recessed area 111 is shown, but in practice the carrier plate 1 can have several recessed areas. The recessed areas can be of any type, for example circular wells, curved or straight grooves, etc. The recessed areas can have a width of, for example, 10 microns or less, but depending on the application, recessed areas of larger size can also be contemplated. In the example shown in FIG. 2, the entire first surface 11 is provided with a dielectric coating 4. Alternatively, the dielectric coating 4 may be provided exclusively in the parts of the first surface 11 defined by the recessed areas 111 and not be present outside these areas. The recessed areas 111 are filled with a functional material 2 that is to be deposited on the target. As further shown diagrammatically in Figure 2, the dielectric coating 4 comprises a series of dielectric coating layers 41, 42, 43 with alternating refractive indices. The dielectric coating layers 41, 42, 43 are deposited with uniform thickness so that the dielectric coating 4 has a relatively high reflectivity for monochromatic radiation R3B incident thereon in a normal direction and a relatively low reflectivity for monochromatic radiation R3S incident thereon in an off-normal direction, i.e. at an angle of 45 degrees.

[0035] In operation of the deposition device, the controller 8 causes the monochromatic radiation source 3 to render monochromatic photon radiation R3 at an intensity and duration that causes transfer of the functional material 2 from one or more recessed areas 111 to the target surface 51. The monochromatic radiation source 3 directs the monochromatic radiation R3 towards the second side 12 of the carrier plate 1. To that end, the monochromatic radiation source 3 may include a laser, for example an excimer laser or a scanning laser, and optional further optical components, such as a telecentric lens.

[0036] As shown diagrammatically in Fig. 2, monochromatic radiation R3B directed towards the bottom 111B of the recessed area 111 is incident on the dielectric coating 4 in a perpendicular direction, so that a relatively large part of it is reflected. In contrast, monochromatic radiation R3S directed towards the sidewall 111S of the recessed area 111 is incident on the dielectric coating 4 in an off-perpendicular direction, so that only a relatively small part of it is reflected. Thereby, the radiation intensity at the bottom 111B of the recessed area 111 is reduced compared to the case without the dielectric coating 4. As a result, the difference between the heat fluxes developed near the sidewall 111S and the bottom 111S is reduced.

[0037] A first example is shown in more detail in Figures 3A, 3B, where Figure 3A shows a portion of the bottom 111B of the recessed area 111 and Figure 3B shows a portion of the sidewall 111S of the recessed area 111. In the example shown, the substrate 10 of the plate is made of silicon dioxide and the dielectric coating 4 is provided with a first high refractive index (n = 2.4) layer 41 of TiO2 having a thickness of 40 nm, a first low refractive index (n = 1.45) layer 42 of SiO2 having a thickness of 40 nm and a second high refractive index layer 43 of TiO2 having a thickness of 40 nm. Also provided is a protective coating layer 45 of Al2O3 having a thickness of 40 nm. The latter has a refractive index of n = 1.75.

[0038] It should be noted that in dielectric mirrors, the thickness of the layers times their refractive index is typically ¼ of the wavelength of the radiation they reflect, so that high refractive index layers are thinner than layers with a low refractive index. In the present application, it is not necessary for the dielectric coating to reflect all radiation, but it is sufficient that the radiation directed towards the bottom of the recessed portion is attenuated to a sufficient degree to achieve a substantially homogeneous distribution of the transmitted heat flux over the inner surface of the recessed area. A suitable coating that meets this requirement can be selected using simulations without undue effort. For example, given the following inputs: wavelength λ of the monochromatic radiation used R3Starting from the selection of the inclination angle of the recessed element walls, the number of dielectric layers in the dielectric coating, and mutually different dielectric materials for these layers, the thicknesses can be varied in the simulation to determine what thickness achieves the required attenuation. It can be assumed in the simulation that the layer thicknesses are equal or that the layer thicknesses of the high and low refractive index layers have a fixed thickness ratio to each other, thereby only one parameter needs to be varied in the simulation. https: / / www.filmetrics.com / reflectance-calculator provides a good simulator for this.

[0039] At each interface 10-41, 41-42, 42-43, and 43-45, reflections occur that enhance or cancel each other depending on the path length difference. The path length through each layer is the product of the layer's thickness (d) and its refractive index (n).

[0040] The intensity of the reflection at the interface of successive layers depends on their refractive indices (n o , n s ) depending on

[0041]

number

[0042] The degree to which the reflections cancel each other out depends on their phase difference.

[0043] In one example, the wavelength λ of the monochromatic radiation source used R3 Therefore, for layers 41, 42, 43, and 45, the two-way optical path length (*λ) for radiation incident in a direction normal to the surfaces expressed as a fraction of a wavelength is R3 ) is as follows:

[0044] [Table 1]

[0045] At the center of the recessed area, the angle of incidence of the light is transverse to the plane of the layer. The various partial reflections are out of phase, but not perfectly anti-phase, so that a portion of radiation R3B is reflected and does not reach the bottom 111B of the recessed area 111.

[0046] 3B shows radiation R3S being directed towards the sidewall 111S of the recessed area 111, where the path length increases when radiation R3S has a direction that deviates from the normal direction of the coating 4. Therefore, partial reflections occurring at the layer interfaces are mostly out of phase, resulting in a relatively small portion of radiation R3S being reflected, so that most of it is able to reach the sidewall 111S of the recessed area 111.

[0047] FIG. 4 shows the relationship between normalized heat flux (normalized power density) and the angle of incidence of the light ray. In this example, the normalized heat flux gradually increases from about 1 to 1.8 as the angle increases from 0 to 45 degrees, and then decreases to 0 as the angle is further reduced to 90 degrees. At an angle of 70 degrees, which corresponds to the angle of the side wall 111S, the normalized heat flux is approximately equal to 1. As a result, a substantially uniform heat flux is achieved within the recessed area 111. The heat flux transmitted through the face is proportional to the power density (W / m 2 ) The normalized heat flux is a dimensionless value obtained by dividing the heat flux for a particular angle by the heat flux at an angle of 0. In some cases, it may be desirable for the heat flux through the sidewalls of the recessed area to be slightly (e.g., about 5 or 10%) greater than the heat flux through the bottom, so that the sides separate slightly before the bottom does. This can further reduce the risk of shear forces developing.

[0048] In another example, the wavelength λ of the monochromatic radiation source used R3has a thickness of 308 nm and the dielectric coating 4 comprises a first high refractive index (n=2.1) layer 41 of HfO2 having a thickness of 38 nm, a first low refractive index (n=1.45) layer 42 of SiO2 having a thickness of 38 nm and a second high refractive index layer 43 of HfO2 having a thickness of 38 nm. Also provided is a protective coating layer 45 of Al2O3 having a thickness of 25 nm. The latter has a refractive index of n=1.75.

[0049] [Table 2]

[0050] 5 shows the normalized heat flux as a function of incidence angle for this example. The dependence of the normalized heat flux on incidence angle is qualitatively the same as in the previous example, but there is a quantitative difference. At angles ranging from 0 degrees to about 65 degrees, the normalized heat flux does not differ from the reference value of 1 by more than about 10%. Thereby, recessed areas 111 having various sidewall angles within this angle range can be provided in the carrier plate, all of which have a substantially uniform distribution of heat flux across their bottom and sidewalls.

[0051] Figure 6 shows an alternative embodiment of the claimed deposition device. Parts therein corresponding to those in figure 2 have the same reference numbers. As an additional feature, the non-recessed part of the first side 11 of the carrier plate is provided with a reflective coating 6, for example a reflective metal coating or a further dielectric coating 6, which substantially reflects (R3R) monochromatic radiation R3. The dielectric coating 4, which extends beyond the further dielectric coating 6, can thereby cooperate with the dielectric coating 6, since the dielectric coating 4 is already designed to partially reflect incident radiation perpendicular to the surface. The further dielectric coating 6 below the dielectric coating 4 realizes an additional dielectric coating layer that further improves the reflectivity outside the recessed area.

[0052] Thereby, it is avoided that any functional material 2'' present in these areas is transferred to the target surface 51 even when monochromatic radiation R3 is directed thereto. It is not necessary for the reflective coating 6 to completely reflect the radiation R3. It is sufficient that the monochromatic radiation R3 is sufficiently reduced in intensity to avoid transfer.

[0053] 6, the recessed area 111 further comprises a photon radiation absorbing layer 9 between the dielectric coating 4 and the functional material 2. Thereby, photon radiation is converted into heat very efficiently, regardless of the type of functional material 2 used.

[0054] 7 shows a schematic diagram of a method for controlled deposition of a functional material onto a target surface using monochromatic radiation having a wavelength. The method comprises a step S1, in which a transparent carrier plate is provided having a substrate with a first and a second mutually facing surface, whereby a first surface having one or more recessed areas is realized. In one embodiment, step S1 comprises a first sub-step S1A, in which a transparent carrier plate, for example made of glass or silicon oxide, is provided, and a second sub-step S1B, in which the first surface comprises one or more recessed areas.

[0055] In the embodiment of FIG. 7, an additional sub-step S1C is performed. In this sub-step S1C, a reflective coating is deposited on the first side, which substantially reflects monochromatic radiation incident normally on the reflective coating. For example, sub-step S1C comprises depositing a reflective metal coating, for example a layer of silver. Preferably, however, the dielectric coating is applied using a series of sub-sub-steps, in which a dielectric coating layer is deposited afterwards to form a dielectric mirror that substantially reflects normally incident monochromatic radiation of said wavelength (optionally in combination with the dielectric coating 4). Compared to using a metal coating, the amount of heat absorption may be relatively modest in the dielectric mirror, thereby reducing the risk of damage. In the example of FIG. 7, sub-step S1C is performed before providing the first side with one or more recessed areas in step S1B. As a result, a plate is obtained as used in the deposition device of FIG. 6, the non-recessed part of the first side 11 of the plate 1 being provided with a reflective coating 6 that substantially reflects monochromatic radiation R3. As discussed with reference to FIG. 6, this reduces the risk of unintentionally transferring material outside the recessed portion. In this embodiment of the method, substep SB1 is performed after substep S1C, so that there is no need to precisely align the deposition process in substep S1C. In substep S1C, the dielectric coating 6 or other reflective coating can simply be deposited over the entire first side of the plate, and in substep S1B, this coating is locally removed in the part of the first side occupied by the recessed portion. Nevertheless, it can be intended to perform substep S1C after substep S1B, provided that care is taken so that the first side occupied by the recessed portion remains free of material used in the reflective coating.

[0056] In step S2 of the method, a dielectric coating is deposited. Step S2 includes a series of substeps, in which each subsequent substep deposits a dielectric coating layer having a refractive index different from that of the dielectric coating layer deposited in the previous substep. It is sufficient that the dielectric coating obtained thereby extends within the portion of the first surface defined by the one or more recessed areas, but alternatively the dielectric coating may also extend beyond the one or more recessed areas. Typically, the dielectric coating is deposited over the entire surface of the plate, thereby obviating mask and alignment problems.

[0057] The dielectric coating has a relatively high reflectivity for monochromatic radiation that is normally incident on the dielectric coating compared to the reflectivity for said monochromatic radiation that is incident at an angle of 45 degrees to the dielectric coating.

[0058] In a subsequent step S3, one or more recessed areas are filled with a functional material, for example copper, aluminum, tungsten, chromium, polysilicon, which is deposited. Other materials than metals are also suitable for use as functional materials. The functional material can be provided, for example, as an ink in which conductive particles are suspended. The rheological properties of the functional material can be modified by additives or solvents, for example to obtain shear-thickening, shear-thinning, thixotropic, rheopexy, or Bingham plastic behavior. In particular, donor materials with shear-thinning behavior are preferred. Donor materials with this behavior have a viscosity that decreases with the rate of shear strain. Shear-thinning donor materials remain as a stable layer on the donor substrate, but are relatively easily deformed when deposited. By way of example, the functional material is a viscous silver nanoparticle ink with a high metal loading.

[0059] It should be noted that further process steps may be performed before the recessed area or areas are filled with functional material. For example, a photon radiation absorbing layer may be deposited after the step of depositing a dielectric coating and before the step of filling the recessed area or areas with said functional material. As mentioned above, this improves the conversion of monochromatic radiation into heat. Alternatively or additionally, a vaporizable material may be deposited in the recessed area or areas before filling with the functional material.

[0060] After the recessed area or areas have been filled with a functional material in step 3, the transparent carrier plate is ready for use in a deposition device, for example as shown in FIG. 2 or FIG.

[0061] Thereby, for example as shown in FIGS. 2 and 6, the transparent carrier plate 1 is positioned between the monochromatic radiation source 3 and the target surface 51 of the target, with the first surface 11 facing the target surface 51.

[0062] In operation, the monochromatic radiation R3 of the monochromatic radiation source 3 is directed in step S4 towards the second side 12 of the plate 1. Therewith, the monochromatic radiation R3 has an intensity and duration which causes a transfer S5 of the functional material 2 from one or more recessed areas 111 to the target surface 51. The optimum values ​​of the intensity and duration can be determined by regular tests of the transmittance of the selected functional material and coating layer. The duration of the thermal radiation is typically short, for example in microseconds, and usually shorter, in nanoseconds. In practice, good results with moderate technical requirements can be obtained with pulse durations of the order of a few ns to tens of ns. Nevertheless, in some cases even shorter pulse durations may be applied, for example in the range of 10 to 500 ps. In a test phase, the intensity (for example around 0.1 J / cm 2 from relatively low values ​​(e.g., about 1 J / cm 2Instead of changing it to a relatively high value corresponding to the exposure (fluence), it is possible to determine at which value or value range the transfer of the functional material 2 is optimal from the perspective of deposition accuracy.

[0063] According to one method, the entire second surface 12 of the plate 1 is irradiated with light rays having a uniform power density. In that case, a uniform exposure having an exposure value equal to the product of the power density and the exposure time is achieved.

[0064] According to another method, as shown in FIG. 8, a scanning light ray that is scanned at a speed v in the scanning direction Sy parallel to the axis y is used along the second surface 12 facing the recessed area 111 (here, the groove indicated by the dotted line) of the first surface.

[0065] In this case, the exposure E(x,y) can be determined as follows.

[0066]

Equation

[0067] In the above equation, P(.,.) defines the spatial distribution of the light ray R3, and Q() defines how the total light power changes with time t.

[0068] FIG. 8 shows the footprint 31 of the scanning light ray when the scanning light ray is pulsed during the scanning period. The previous pulse is shown as a dotted circle, for example 31''. As a result of the above scan, the energy density uniformity of the second surface can be obtained in the scanning direction on the condition that the distance between the subsequently pulsed areas 31'' and 31 is small, for example, the distance must be less than 1 / 3 times the size of the footprint in the scanning direction. Also, in the x direction perpendicular to the scanning direction, the variation of the exposure can be limited. For example, the maximum exposure Emax and the minimum exposure Emin in the range of x1 < x < x2 may be required to be bound by the following relational expression.

[0069]

number

[0070] This can be achieved with a highly uniform light beam. Alternatively, as shown in FIG. 8, the light beam can be applied with a footprint that extends beyond the boundaries of the recessed area 111 and is sufficiently uniform within those boundaries. When using a pulsed laser, the pulse frequency must be sufficiently high, for example, a frequency of 100 kHz or higher, to uniformly heat the functional material. Continuous wave lasers can also be used where the timed release is controlled by the scan speed.

[0071] As mentioned with reference to FIG. 6, precautions may be taken to reduce the risk of inadvertent transfer of functional material as a result of exposure of the plate to light in areas outside the recessed areas.

[0072] 7, which further shows that once the deposition processes of steps S4, S5 are completed, the recessed areas of the carrier plate can be refilled with functional material in step S3, so that the carrier plate is ready for reuse. Optionally, the carrier plate, and in particular its first side, can be cleaned in an additional step S6 before being refilled in step S3.

[0073] Figures 9A-9C show a further embodiment of the transparent carrier plate 1. Parts therein corresponding to those in Figures 2 and 6 have the same reference numbers. For clarity, the dielectric coating 4 is shown without further details. The dielectric coating 4 on the first side 11 can have a stack of dielectric coating layers 41, 42, 43, for example as shown in more detail in Figures 3A, 3B and described above with reference to Figures 3A, 3B, 4 and 5. Other layers, such as protective coatings, can also be provided. In the embodiment shown in Figures 9A-9C, the transparent carrier plate 1 additionally comprises a grayscale mask 122 to control the heat flux of the monochromatic photon radiation R3.

[0074] In the example shown in Fig. 9A, the grayscale mask 122 has transparent first zones 122BS corresponding to the areas defined by the recessed areas 111. The grayscale mask 122 has complementary opaque second zones 122O. When the plate 1 is exposed to radiation R3, the part of the radiation incident on the transparent first zones 122BS is transmitted towards the dielectric coating 4 in the recessed areas 111, thereby achieving that the transmitted heat flux in the plane of the side wall 111S and the transmitted heat flux in the plane of the bottom wall 111B have substantially the same magnitude.

[0075] In the example shown in FIG. 9B, the grayscale mask 122 has a central zone 122B corresponding to the surface area of ​​the bottom wall 111B of the recessed area 111, a boundary zone 122S corresponding to the surface area of ​​the side wall 111S of the recessed area 111, and a complementary zone 122O. In this example, the grayscale mask 122 is provided to control the heat flux of the monochromatic photon radiation R3 and, in cooperation with the dielectric coating 4, achieve at least a substantially homogeneous transmitted heat flux on the inner surface of one or more recessed areas 111. Thereby, an additional degree of freedom is available. For example, if recesses having sidewalls with mutually different inclination angles are provided therein, the grayscale mask 122 can be designed to achieve at least a substantially homogeneous transmitted heat flux even if the dielectric coating is not able to achieve an adequate compensation for the entire range of angles of the sidewalls. For example, in that case, a plate with the coating described with reference to FIG. 4, in addition to recesses with a wall angle of 70 degrees, also includes recesses with a wall angle of 45 degrees or 80 degrees. In the example shown in Figure 9B, for example, the central zone 122B has a transmittance of 60% and the boundary zone 122S has a transmittance of approximately 100%. For a recess having sidewalls at an angle of 80 degrees, a substantially homogenous transmitted heat flux can then be obtained across the inner surface of the recess using the coating described with reference to Figure 4. In the example of Figure 9B, the transmittance of the complementary zone 122O is also approximately 100%.

[0076] In the example shown in FIG. 9C, a grayscale mask 122 combines the functionality provided in the examples of FIGS. 9A and 9B. [Explanation of symbols]

[0077] 1 transparent carrier plate 2 Functional materials 3 Monochromatic radiation sources, scanning lasers, excimer lasers, monochromatic photon radiation sources 4. Dielectric Coating 5 goals 6 Reflective Coating 7 Holder 8 Controller 9 Photon emission absorption layer 10 Substrate 11 First Side 12 The Second Side 31 Footprint 31'' area 41 Dielectric coating layer, first high refractive index layer 42 Dielectric coating layer, first low refractive index layer 43 Dielectric coating layer, second high refractive index layer 45 Protective layer, protective coating layer 51 Target plane 111 Well, recessed area 111B bottom 111S side wall 122 Grayscale Mask 122B Central Zone 122BS Transparent 1st Zone 120O Second opaque zone, complementary zone 122S Boundary Zone R3 Monochromatic radiation, monochromatic photon radiation R3B Monochromatic radiation, monochromatic radiation source R3S Monochromatic radiation λ R3 wavelength

Claims

1. Wavelength (λ Ｒ３ 1. A method for the controlled deposition of a functional material (2) onto a target surface (51) using monochromatic radiation (R3) having a - providing (S1) a transparent carrier plate (1) having a substrate (10) with first and second mutually opposing faces (11, 12, respectively), thereby realizing (S1B) a first face (11) having one or more recessed areas (111); - depositing (S2) on said first surface (11) a dielectric coating (4) comprising a series of dielectric coating layers (41, 42, 43) with alternating refractive indices, said dielectric coating (4) having a relatively high reflectivity for said monochromatic radiation (R3) incident perpendicularly to said dielectric coating (4) compared to a reflectivity for said monochromatic radiation (R3) incident at an angle of 45 degrees to said dielectric coating (4); filling (S3) said one or more recessed areas (111) with said functional material (2); positioning said transparent carrier plate (1) between a monochromatic radiation source (3) and said target surface (51), said first surface (11) facing said target surface (51); directing (S4) said monochromatic radiation (R3) towards the second surface (12) of said plate (1), said monochromatic radiation (R3) having an intensity and duration that causes a transfer (S5) of a functional material (2) from said one or more recessed areas (111) to said target surface (51); A method comprising:

2. The dielectric coating layers (41, 42, 43) are arranged to cover the wavelength (λ) of the monochromatic radiation (R3). Ｒ３ 2. The method of claim 1, wherein the thickness of the first layer is in the range of 0.05 to 0.15 times the thickness of the second layer.

3. 3. The method according to claim 1 or 2, further comprising, before realizing (S1B) the first face (11) having one or more recessed areas (111), a step (S1C) of depositing on the first face (11) a reflective coating (6) that substantially reflects the monochromatic radiation (R3) incident thereon.

4. 2. The method according to claim 1, wherein a scanning laser (3) is used to generate the monochromatic radiation (R3).

5. 5. The method according to claim 4, wherein the monochromatic radiation (R3) is directed to the second face (12) of the plate (1) via a telecentric lens, ensuring equal angles of incidence over the area covered by the monochromatic radiation (R3).

6. 5. The method according to claim 4, wherein an excimer laser (3) is used to generate the monochromatic radiation (R3).

7. 7. The method according to any one of claims 1 to 6, further comprising the step of depositing a photon radiation absorbing layer (9) after the step of depositing the dielectric coating and before the step (S3) of filling the one or more recessed areas (111) with the functional material (2).

8. Wavelength (λ Ｒ３ 1. A plate (1) comprising a functional material (2) to be deposited onto a target surface (51) using monochromatic photon radiation (R3) having a wavelength of 100 nm to 150 nm, the plate (1) comprising a substrate (10) having a first surface (11) directed towards the target surface and a second surface (12) for receiving the monochromatic photon radiation, the first surface (11) being patterned with one or more recessed areas (111) having a dielectric coating (4) and being filled with the functional material, the dielectric coating (4) comprising a series of dielectric coating layers (41, 42, 43) having alternating refractive indices, the dielectric coating (4) having a relatively high reflectivity for the monochromatic radiation (R3) perpendicularly incident on the dielectric coating (4) compared to a reflectivity for the monochromatic radiation (R3) incident at an angle of 45 degrees to the dielectric coating (4).

9. The dielectric coating layers (41, 42, 43) are arranged to have a wavelength (λ Ｒ３ 9. The plate (1) according to claim 8, having a thickness in the range of 0.05 to 0.15 times the thickness of the plate (1) of claim 8.

10. 9. The plate (1) according to claim 8, wherein said dielectric coating (4) covers said first face (11) in a full-surface manner.

11. 11. Plate (1) according to any one of claims 8 to 10, wherein the dielectric coating (4) is covered with a protective layer (45).

12. 12. The plate (1) according to any one of claims 8 to 11, wherein a non-recessed portion of the first face (11) is provided with a reflective coating (6) that substantially reflects the monochromatic radiation (R3).

13. 13. The plate (1) according to any one of claims 8 to 12, comprising a photon radiation absorbing layer (9) between the dielectric coating and the functional material (2) at least in the one or more recessed areas (111).

14. 14. The plate (1) according to any one of claims 8 to 13, comprising a greyscale mask (122) on its second side (12) for controlling the heat flux of said monochromatic photon radiation (R3) and for cooperating with said dielectric coating (4) to achieve at least a substantially homogeneous transmitted heat flux on the inner surface of said one or more recessed areas (111) and / or for suppressing the transmission of said radiation outside these areas.

15. A plate (1) according to any one of claims 8 to 14, a holder (7) for holding a target (5) with a target surface (51) facing the first surface (11) of the plate; a monochromatic photon radiation source (3) for rendering said monochromatic photon radiation (R3) directed towards said second face (12) of said plate; a controller (8) causing the monochromatic radiation source (3) to render the monochromatic photon radiation (R3) at an intensity and duration that causes a transfer of a functional material (2) from the one or more recessed areas (111) to the target surface (51); A deposition device comprising:

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