Process for depositing a layer of inorganic or hybrid organic / inorganic materials on a substrate
By employing a target with variable thickness and overlapping sub-targets in the sublimation deposition method, the method addresses the challenge of achieving uniform deposition on large substrates, simplifying target manufacturing and ensuring consistent material distribution.
Patent Information
- Application Number
- FR2022011437
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-11-03
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2042-11-03
AI Technical Summary
The challenge lies in achieving uniform deposition of inorganic or hybrid organic/inorganic materials on large surface substrates (greater than or equal to 25 cm2) using sublimation deposition methods, as existing techniques face difficulties in maintaining uniformity and require high-pressure presses for target fabrication.
The method involves preparing a target comprising multiple sub-targets with variable thicknesses and/or overlapping sub-targets, which are positioned in a sublimation furnace opposite the substrate. This configuration allows for non-uniform thickness and overlap to compensate for sublimation occurring at the edges of the sub-targets, ensuring uniform deposition across large areas.
This approach enables the deposition of uniform layers of inorganic or hybrid organic/inorganic materials on large substrates, simplifying the target manufacturing process by eliminating the need for high-pressure presses and ensuring consistent material distribution.
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Abstract
Description
Title of the invention: Method for depositing a layer of inorganic or hybrid organic / inorganic materials on a substrate Technical field
[0001] The invention relates to the sublimation deposition of layers of inorganic or organic / inorganic hybrid materials such as perovskites. In particular, the invention relates to sublimation deposition using targets comprising several sub-targets and allowing the deposition of uniform layers over a large area (typically over an area greater than or equal to 25 cm2).
[0002] BACKGROUND
[0003] The deposition of layers of inorganic or organic / inorganic hybrid materials is used in various applications, such as the manufacture of electronic, optical or optoelectronic devices based on inorganic or organic / inorganic hybrid materials (for example, these may be LEDs, photodetectors, scintillators, or even transistors). Currently, it is possible to deposit a layer of inorganic or organic / inorganic hybrid materials, such as perovskites, using the close space sublimation (CSS) method. For this, a target comprising the inorganic or organic / inorganic hybrid materials is placed on a susceptor, facing a substrate on which the layer is to be deposited, in a close space sublimation furnace. The furnace also includes a heating system as well as a pumping system for achieving a vacuum in the furnace.When the target is heated with the heating system, the target materials are sublimated and condense on the substrate. The deposition is directional, that is to say that the geometry of the target is found in that of the deposit (therefore the surface of the deposit is identical to that of the target). Indeed, the sublimation is normal to the surface of the target and the mean free path of the species in the vapor phase is greater than or comparable to the distance between the target and the substrate.
[0004] The targets are made of compacted powder making it possible to obtain a solid target of uniform thickness, and thus making it possible to obtain a uniform layer deposited on the substrate. However, when depositing on large surfaces (for example greater than 25 cm2), it is difficult to obtain targets from the surface of the deposit. In particular, since the pressure density for making a target must be constant, the force exerted by the press must be increased proportionally to the surface. Thus, for large surfaces, presses exerting high pressures are necessary. In addition, since the compacted powders are friable and the targets are of low thickness, a pressure density even higher may be necessary to obtain a large area solid target with uniform thickness.
[0005] Thus, it is possible to produce targets in the form of paving, that is to say several sub-targets each representing a portion of the target. The apparent surface of the sub-targets is the size of the deposit and arranged in a continuous surface (i.e. not having "holes"). In other words, the sub-targets are targets with smaller surfaces which can then be assembled on a susceptor. Targets with smaller surfaces are more easily manufactured because they do not require high-pressure presses. For example, there are targets comprising a paving of sub-targets having rectangular or square sub-targets, as illustrated for example in [Fig.l] representing a target comprising four sub-targets seen from above.
[0006] However, sublimation occurs not only normally on the upper surface of the sub-targets of the tiling but also by the edges of the sub-targets. Consequently, the surface area of the sub-targets decreases during deposition, they become disjointed and the deposit with respect to the joints is less thick. Thus, a simple tiling, as shown in [Fig.l] does not allow a uniform deposition to be obtained.
[0007] SUMMARY
[0008] To address the problems encountered in the state of the art, the invention relates to a method for depositing by sublimation a uniform layer of inorganic or hybrid organic / inorganic materials on a large surface substrate (typically on surfaces greater than or equal to 25 cm2).
[0009] In particular, the invention improves the situation by proposing a method for depositing a layer of an inorganic or hybrid organic / inorganic material on a substrate for the manufacture of an electronic, optoelectronic and / or optical device, said method comprising: a step of preparing a target; a step of positioning the target on a susceptor in a sublimation furnace, said target being positioned in the furnace opposite the substrate to be covered; and a step of heating the target via the susceptor to deposit the layer of inorganic material on the substrate by sublimation; characterized in that the target comprises a plurality of sub-targets, the step of preparing the target makes it possible to obtain sub-targets having a variable thickness and / or the step of preparing the target makes it possible to obtain overlapping sub-targets.
[0010] As indicated above, sublimation is carried out not only by the center of the sub-targets but also by the edges of the sub-targets of the tiling. The invention is particularly advantageous because it makes it possible to compensate for sublimation by the edges by proposing a non-uniform thickness and / or with an overlap between the several sub-targets. Thus, it is possible to manufacture sub-targets allowing the sublimation of materials onto large-area substrates while obtaining a uniform sublimated layer. In addition, the invention is particularly advantageous because it does not require the use of a high-pressure press and thus simplifies the manufacture of targets.
[0011] In one embodiment, each sub-target having a central region and a peripheral region, the thickness of said sub-target is greater in said peripheral region.
[0012] In one embodiment, at least two sub-targets of the target nest.
[0013] In one embodiment, the two sub-targets are beveled.
[0014] In one embodiment, the two sub-targets are slot-shaped.
[0015] In one embodiment, the sub-targets overlap to form multiple strata.
[0016] In one embodiment, each layer has the same thickness.
[0017] In one embodiment, each layer has a different thickness.
[0018] In one embodiment, at least two layers are made of different material.
[0019] In one embodiment, the sub-targets overlap in a manner disorganized.
[0020] The invention also improves the situation by proposing a target for carrying out a deposition by sublimation of a layer of one or more inorganic or hybrid organic / inorganic materials on a substrate, the target being formed of several sub-targets, the sub-targets having a variable thickness and / or overlapping. Brief description of the drawings
[0021] The invention will be better understood and other advantages will appear on reading the description which follows, given without limitation and thanks to the figures among which:
[0022] [Fig-1] [Fig.l] illustrates a state-of-the-art example of a target with a tiling simple ;
[0023] [Fig.2] [Fig.2] represents an example of a method of depositing by sublimation a layer of one or more inorganic or hybrid organic / inorganic materials on a substrate;
[0024] [Fig.3] [Fig.3] represents an example of a system for depositing a layer of one or more inorganic or hybrid organic / inorganic materials on a substrate by sublimation;
[0025] [Fig.4a] [Fig.4a] represents an example of a target comprising a tiling of sub-targets, seen in section;
[0026] [Fig.4b] [Fig.4b] represents an example of a target comprising a tiling of sub-targets seen in section;
[0027] [Fig.5] [Fig.5] represents an example of a target comprising a sub-tiling targets seen in section;
[0028] [Fig.6a] [Fig.6a] represents an example of a target comprising a sub-tiling targets seen in section;
[0029] [Fig.6b] [Fig.6b] represents an example of a target comprising a sub-tiling targets seen in section; and
[0030] [Fig.6c] [Fig.6c] represents an example of a target comprising a sub-tiling targets seen in section; DETAILED DESCRIPTION
[0031] [Fig.2] illustrates a method 100 for depositing a layer of an inorganic or hybrid organic / inorganic material on a substrate 302 for the manufacture of an electronic, optoelectronic and / or optical device.
[0032] In block 1002, the method 1000 comprises a step of preparing a target 500a, 500b, 500c, 500d, 500e, 500f. As illustrated in FIGS. 4a to 6c representing examples of targets, the target 500a, 500b, 500c, 500d, 500e, 500f comprises a plurality of sub-targets 502. The step of preparing the target 500a, 500b, 500c, 500d, 500e, 500f makes it possible to obtain sub-targets 502 having a variable thickness and / or the step of preparing the target 500a, 500b, 500c, 500d. 500e, 500f allows overlapping sub-targets to be obtained. In particular, Figures 4a, 4b, 6a, 6b and 6c show targets 500a, 500b, 500d, 500e, 500f having overlapping sub-targets 502 and Figure 500c shows a target 500c having sub-targets having a variable thickness.
[0033] For example, when the sub-targets overlap, the sub-targets 502 form a target for which over a fraction (from 1% to 25%) of a total surface of the target, several sub-targets are superimposed in the thickness of the target. The overlap can be established over a few millimeters (from 0.5 to 10 mm and preferably 2 mm). In another example, when the sub-targets overlap, the target comprises sub-targets 502 for which over the entire surface of the target, several sub-targets 502 are superimposed in the thickness of the target. This superposition can be obtained by any number of sub-targets greater than two (and preferably less than five). The overlap can be ordered (ordered arrangement of the sub-targets, characterized in particular by the fact that at each point of the paving the number of sub-targets superimposed in the thickness is identical) or disordered.
[0034] For example, as illustrated in Figures 4a and 4b, at least two sub-targets 502 of the target 500a fit together. In particular, in [Fig.4a], the sub-targets 502 are beveled. In the example of [Fig.4b], the sub-targets 502 are shaped like niche. In particular, in these two examples, the targets 500a, 500b comprise at least three sub-targets, a first sub-target, a second sub-target and a third sub-target. The three sub-targets are placed side by side. Each of the targets has the same volume and the same bevel angle, with an upper side and a lower side, one of the sides being larger than the other. For the first and third sub-targets, the lower side is larger than the upper side and for the second sub-targets, the upper side is larger than the lower side.
[0035] In another example, target 500a may include beveled sub-targets 502 and crenellated sub-targets 502.
[0036] In another example, as illustrated in [Fig. 5], each sub-target 502 has a central region and a peripheral region, and the thickness of the sub-target 502 is greater in the peripheral region. The thickness may vary gradually as shown in [Fig. 5], or abruptly (i.e., for example, with a rim placed on the sub-target 502). It is noted that [Fig. 5] is in section, so the variation in thickness is shown only on two of the ends of the sub-targets 502.
[0037] In another example, as illustrated in Figures 6a-6c, the sub-targets overlap to form multiple layers. For example, in the example of Figures 6a and 6b, each layer has the same thickness. In the example of [Fig. 6c], each layer has a different thickness. Further, in the example of [Fig. 6c], the sub-targets 502 overlap in a disorganized manner. In another example, the layers may have a different thickness while overlapping in an organized manner.
[0038] It is noted that the targets 500a, 500b, 500c, 500d, 500e, 500f of FIGS. 4a-6c are shown in section. Viewed from above, the sub-targets 502 may be rectangular, square or parallelepiped. In other examples, the sub-targets may be circular, triangular or any other shape suitable for the application for which the target 500a, 500b, 500c, 500d, 500e, 500f is used. In addition, the number of sub-targets 502 is adapted to the dimensions of the substrate 302 on which the layer of inorganic or organic / inorganic hybrid materials is sublimated. For example, in the example of [Fig.4a], the target 500a comprises three sub-targets 502 when viewed in cross-section. The target 500a may comprise two or more sub-targets 502. In addition, when viewed from above, the target 500a may form a square, a rectangle, or any other shape suitable for the application for which the target 500a, 500b, 500c, 500d, 500e, 500f is used.
[0039] The targets 500a, 500b, 500c, 500d, 500e, 500f are formed using pressed inorganic or organic / inorganic hybrid material powders. Each sub-target 502 is fabricated individually and then the sub-targets are assembled to form the target 500a, 500b, 500c, 500d, 500e, 500f.
[0040] The targets 500a, 500b, 500c, 500d, 500e, 500f are made of inorganic or organic / inorganic hybrid materials which may be, for example, perovskites, such as perovskites of general chemical formula ABX3, including mixed compositions such as A(1) 1_(y2+...+yn) A® y2 ...A® yn B(1) 1_(z2+...+zm) B® z2 .. ,B(m) zm X® 3-(x2+ ...+xp) X® x2 ...X® xp with A® and B® cations and X® anions, the compositions respecting electronic neutrality, with y2 and yn the respective proportions of the cations A® and A® , z2 and zm the respective proportions of the cations B® and B®', and x2 and xp the respective proportions of the anions X® and X®.
[0041] For example, A is selected from Cs, Rb, K, Li, and Na (inorganic perovskite) or CH3NH3, CH5N2 (hybrid perovskite); B is selected from Pb, Sn, Ge, Hg, and Cd; X is selected from Cl, Br, I, and F. For example, it is CsPbBr3.
[0042] In another example, it is also possible to have alloys of 2 to 5 elements on one of the sites, on two of the sites or on all three sites A, B and X. For example, one can choose a material with X=Clk Bp Ii_k_iwith 0 <k,l<l et 0<k+l<l. Il en va de même pour les sites A et B.
[0043] In another example, it is also possible to have double meshes with A= A'2, B=C *+ D 3+ and X3=X'6, i.e. a material of formula A'2C'+ D3+ X6 with: A' chosen from Cs, Rb, K, Li, and Na; X' chosen from Cl, Br, I, and F; C'1+ chosen from Ag, Au, Tl, Li, Na, K, and Rb and D3+ chosen from Al, Ga, In, Sb, and Bi.
[0044] Preferably, according to this variant, the perovskite material has the formula Cs2AgBiBr 6-
[0045] The invention also applies to all other compositions related to perovskites: materials of composition A2B4+X6 such as for example Cs2Te4+I6, materials of composition A3B23+X9 such as for example Cs3Bi2I9, or other types of materials (Chalcogenides, Rudorffites, etc.).
[0046] In the case where the target 500a, 500b, 500c, 500d, 500e, 500f is of formula ABX3, the target 500a, 500b, 500c, 500d, 500e, 500f can be formed from a mixture of elementary particles A, B and X.
[0047] In other examples, the target 500a, 500b, 500c, 500d, 500e, 500f of formula ABX3 may be formed
[0048] - of a mixture of binary particles AX and BX2,
[0049] - of a mixture of particles AX, BX2 and ABX3,
[0050] - of ABX3 particles, which allows to have directly the good composition and the good phase of the material to be sublimated; these particles could, for example, be small single crystals formed by liquid means, by Bridgman or other solution.
[0051] It is also possible to use mixtures comprising more than two types of binary particles. For example, the compound Cs2AgBiBr6 can be obtained from precursors CsBr, AgBr, and BiBr3.
[0052] In the case where the target 20 is of formula A'2C1+D3+X6, the target can be composed of:
[0053] - a mixture of binary particles A'X, C1+X and D3+X3,
[0054] - of a mixture of particles A'X, C1+X and D3+X3 and A'2C1+D3+X6,
[0055] - of particles A'2C1+D3+X6, which allows to have the right composition directly and the correct phase of the material to be sublimated.
[0056] More complex compositions and / or those involving a greater number of precursors may also be envisaged. Other inorganic or organic / inorganic hybrid materials may also be used such as Cdi_xyHgx ZnyTei_z tSezSt (with 0 <x,y,z,t<l), Sb2(Si_xSex)3 (avec 0<x<l), ou tout autre matériau susceptible d’être déposé par sublimation à faible distance.
[0057] Each target 500a, 500b, 500c, 500d. 500e, 500f of the examples described above is at least 5 cm wide, i.e., at least one side of the target is at least 5 cm. In one example, the targets 500a, 500b, 500c, 500d. 500e, 500f are at least 10 cm wide. In another example, the targets 500a, 500b, 500c, 500d, 500e, 500f are at least 20 cm wide.
[0058] In one example, the target 500a, 500b, 500c, 500d, 500e, 500f comprises sub-targets of different materials. For example, the target 500a, 500b, 500c, 500d, 500e, 500f comprises at least two layers that are made of different materials. For example, in the example of [Fig.6b], the target 500e comprises two layers: an upper layer and a lower layer. The upper layer may be in a first material and the lower layer may be in a second material. In another example, [Fig.5] illustrates the target 500c comprising three sub-targets 502: a first sub-target, a second sub-target and a third sub-target. The first subtarget may be in a first material, the second subtarget may be in a second material, and the third subtarget may be in a third material.
[0059] In block 1004, the method 1000 comprises a step of positioning the target 500a, 500b, 500c, 500d, 500e, 500f, on a susceptor 306 in a sublimation oven 308, the target 500a, 500b, 500c, 500d, 500e, 500f being positioned in the oven 308 opposite the substrate 302 to be covered. The target 500a, 500b, 500c, 500d, 500e, 500f may for example be fabricated on the susceptor 306 which is then placed in the furnace 308. In another example, the target 500a, 500b, 500c, 500d, 500e, 500f is fabricated on a support and transferred to the susceptor 306. The furnace may be a short-distance sublimation furnace. The susceptor 306 is made of conductive materials. The furnace 308 comprises a gas outlet, connected to a pumping system allowing a vacuum Pfour to be reached ranging, for example, from 0.00001 Pa - 1 Pa. The Pfour value depends on the 308 furnace used.
[0060] In block 1006, the method 1000 comprises a step of heating the target 500a, 500b, 500c, 500d, 500e, 500f via the susceptor 306 to deposit the layer of inorganic material on the substrate 302 by sublimation. For example, as illustrated in [Fig. 3] representing system 300 for depositing a layer of inorganic or organic / inorganic hybrid materials on the substrate 302 by sublimation, the susceptor 306 may be placed on a heating element 304. For example, the heating element 304 may be a lamp, a resistor, or any other heating system. Sublimation deposition is performed by heating the susceptor 306 with the heating element 304 with, for example, a temperature of 400°C (± 100°C) and a substrate temperature of 300°C (± 150°C). In order to ensure deposition of the layer, the substrate temperature is 100°C lower (from 300°C to 20°C lower) than the temperature of the target 500a, 500b, 500c, 500d, 500e, 500f.Temperature ramps to reach sublimation temperatures can be, for example, 1°C / s. The temperature can be adapted depending on the materials and thicknesses of the targets.
[0061] The invention described above thus makes it possible to obtain uniform layers of inorganic or hybrid organic / inorganic materials, even for large substrates. Indeed, the sub-targets make it easy to manufacture solid targets. In addition, the overlapping and / or variable thickness sub-targets make it possible to compensate for the fact that sublimation occurs more quickly through the edges of the sub-targets of the tiling than through the center of the sub-targets.
[0062] Although the invention has been illustrated and described in detail using a preferred embodiment, the invention is not limited to the disclosed examples. Other variations may be deduced by those skilled in the art without departing from the scope of protection of the claimed invention. For example, the number of sub-targets per target may vary depending on the applications. In addition, the shapes, thicknesses and number of layers of the sub-targets may vary depending on the applications. The shapes may also be combined.
Claims
Claims
1. A method of depositing a layer of an inorganic or organic / inorganic hybrid material on a substrate for the manufacture of an active layer in an electronic, optoelectronic and / or optical device, said method comprising: - a step of preparing a target; - a step of positioning the target on a susceptor in a sublimation furnace, said target being positioned in the furnace opposite the substrate to be covered; and - a step of heating the target via the susceptor to deposit the layer of inorganic or organic / inorganic hybrid material on the substrate by sublimation;characterized in that the target comprises a plurality of sub-targets arranged in the form of a paving having a continuous surface, each sub-target having a central region and a peripheral region, the step of preparing the target makes it possible to obtain sub-targets having a variable thickness, the thickness of the central region and the thickness of the peripheral region being different.;
2. The deposition method of claim 1, wherein the thickness of said sub-target is greater in said peripheral region.
3. The deposition method of claim 1, wherein at least two sub-targets of the target nest.
4. A deposition method according to claim 3, wherein the two sub-targets are beveled.
5. The deposition method of claim 3, wherein the two sub-targets are crenellated.
6. The deposition method of claim 1, wherein the subtargets overlap to form multiple layers.
7. A deposition method according to claim 6, wherein each layer has the same thickness.
8. A deposition method according to claim 6, wherein each layer has a different thickness.
9. A deposition method according to any one of claims 6 to 8, wherein at least two layers are made of different material.
10. The deposition method of claim 1, wherein the subtargets overlap in a disorganized manner.
11. Target for performing a sublimation deposition of a layer of one or more inorganic or organic / inorganic hybrid materials on a substrate, the target being formed of several sub-targets arranged in the form of a paving having a continuous surface, each sub-target having a central region and a peripheral region, the sub-targets having a variable thickness, the thickness of the central region and the thickness of the peripheral region being different.