INKJET PRINTING PROCESS

Abstract

An only inkjet-printing-based process for depositing functional materials, in various instances PZT, Bi-based material or (K,Na)-based material, on a substrate, in various instances platinized silicon. Substrate templating (via SAMs) and material deposition are both performed by an inkjet printing process. Additionally, a composition to be used as a SAM precursor ink which is a thiol in a solvent mixture. Further, a cartridge for a printing machine with such a composition. Still further, the use of such a cartridge, alone, or as a kit with another cartridge containing a precursor of the functional material, in particular to perform both steps of the printing method. Finally, a product, for instance a microsystem, obtained by the process.

Claims

1.-16. (canceled)

17. An inkjet printing process on a substrate comprising (a) a step of deposition of a self-assembled monolayer (SAM) on the substrate; (b) a step of printing of a material within the boundaries of the SAM, the material being a composition containing at least one of the following: at least one of PZT doped with either Fe, K, Nb, Ta, and Nd; BiFeO.sub.3 or (Bi,Re)FeO.sub.3, where Re is rare-earth metal comprising at least one of La, Nd, Sm, Eu, etc.; (Bi.sub.0.5Na.sub.0.5)TiO.sub.3 or (Bi.sub.0.5K.sub.0.5)TiO.sub.3 and their solid solutions as well as their solid solutions with BaTiO.sub.3; (K,Na)NbO.sub.3 or (K,Na,Li)(Sb,Ta,Nb)O.sub.3 and their solid solutions with (Bi.sub.0.5Na.sub.0.5)TiO.sub.3 and BaTiO.sub.3; at least one of Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, ZnO, or ZnO, doped with Al; at least one of solid solutions of HfO.sub.2—ZrO.sub.2, CrO.sub.2, VO.sub.2, CuO, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4, IrO.sub.2, BaO, SrO, MgO, Y.sub.2O.sub.3, CeO.sub.2, Cs.sub.2O, WO.sub.3, MoO.sub.3, or RuO.sub.2; HfO.sub.2 doped with at least one of Y, Si, Sr, La, Gd, and Al; at least one of In.sub.2O.sub.3 or SnO.sub.2 or any solid solution between In.sub.2O.sub.3 and SnO.sub.2; and at least one of LaNiO.sub.3 or SrRuO.sub.3, wherein both steps (a) and (b) are made by inkjet printing.

18. The printing process according to claim 17, wherein the SAM ink is a composition made of a thiol in a solvent mixture of alcohols and ethers, and the substrate is made of a high surface energy material containing at least a noble metal.

19. The printing process according to claim 18, wherein the solvent mixture of the SAM ink is made of 60 to 90 vol % of 2-methoxyethanol.

20. The printing process according to claim 18 wherein the thiol is 1-dodecanethiol in a quantity of 0.01 to 0.0001 M.

21. The printing process according to claim 17 wherein said material is diluted to 0.2 M with a solvent made of 65 (±5) vol % 2-methoxyethanol, 25 (±5) vol % glycerol and 10 (±5) vol % ethylene glycol.

22. The printing process according to claim 17 wherein the process further comprises at least one of the following steps: (c) drying; (d) pyrolysis; and (e) crystallization.

23. The printing process according to claim 22, wherein the steps (a) to (d) are carried out in that order and are repeated one time or more, defining a cycle, and step (e) is performed after step (d) every n cycle, n being equal or greater than 1, such that a multi-layer functional material is printed on the substrate.

24. The printing process according to claim 17, wherein at least one of the SAM and the material have the following rheological properties: a viscosity within the range 1-15 mPa.Math.s and a surface tension within the range 20-40 mN/m.

25. A composition made of 1-dodecanethiol in a solvent mixture of 2-methoxyethanol and glycerol.

26. The composition according to claim 25, wherein the solvent mixture consists of 60 to 90 vol % of 2-methoxyethanol, the complement being glycerol.

27. The composition according to claim 25, wherein the 1-dodecanethiol is in a quantity of 0.01 to 0.0001 M.

28. A kit, said kit comprising: at least one cartridge for a printing machine containing a composition made of 1-dodecanethiol in a solvent mixture of 2-methoxyethanol and glycerol; and at least one cartridge comprising a composition containing at least one of the following: at least one of PZT doped with either Fe, K, Nb, Ta, and Nd; BiFeO.sub.3 or (Bi,Re)FeO.sub.3, where Re is rare-earth metal comprising at least one of La, Nd, Sm, Eu, etc.; (Bi.sub.0.5Na.sub.0.5)TiO.sub.3 or (Bi.sub.0.5K.sub.0.5)TiO.sub.3 and their solid solutions as well as their solid solutions with BaTiO.sub.3; (K,Na)NbO.sub.3 or (K,Na,Li)(Sb,Ta,Nb)O.sub.3 and their solid solutions with (Bi.sub.0.5Na.sub.0.5)TiO.sub.3 and BaTiO.sub.3; at least one of A12O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, ZnO, or ZnO, doped with Al; at least one of solid solutions of HfO.sub.2—ZrO.sub.2, CrO.sub.2, VO.sub.2, CuO, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4, IrO.sub.2, BaO, SrO, MgO, Y.sub.2O.sub.3, CeO.sub.2, Cs.sub.2O, WO.sub.3, MoO.sub.3, or RuO.sub.2; HfO.sub.2 doped with at least one of Y, Si, Sr, La, Gd, and Al; at least one of In.sub.2O.sub.3 or SnO.sub.2 or any solid solution between In.sub.2O.sub.3 and SnO.sub.2; and at least one of LaNiO.sub.3 or SrRuO.sub.3.

29. The printing process according to claim 17 further comprising preforming the process using a cartridge for a printing machine containing a composition made of 1-dodecanethiol in a solvent mixture of 2-methoxyethanol and glycerol.

30. The printing process according to claim 18, wherein the thiol is 1-dodecanethiol, the solvent mixture of alcohols and ethers is 2-methoxyethanol and glycerol, and the noble metal of the substrate is taken from the group: Pt, Au, Cu, Ir, Pd, Ru.

31. The printing process according to claim 18 wherein the thiol is 1-dodecanethiol in a quantity of 0.001 M in the solvent.

Description

DRAWINGS

[0075] FIG. 1 is an exemplary illustration of a cross section of a substrate, in accordance with various embodiments of the invention.

[0076] FIG. 2 is an exemplary diagram summarizing the preparation of a functional material, in accordance with various embodiments of the invention.

[0077] FIG. 3 illustrates an exemplary embodiment of the printing method, in accordance with various embodiments of the invention.

[0078] FIG. 4 illustrates exemplary top view pictures of the printed pattern of films, in accordance with various embodiments of the invention.

[0079] FIG. 5 exemplarily shows the thickness of the deposition, in accordance with various embodiments of the invention.

[0080] FIG. 6 exemplarily shows the results of a SIMS analysis, in accordance with various embodiments of the invention.

DETAILED DESCRIPTION

[0081] FIG. 1 shows a cross section (not to scale) of a substrate that can be used for the printing process of the invention. The substrate in various instances comprises a silicon base with a platinum coating.

[0082] FIG. 2 details the process employed to obtain a functional material. In this example, PZT ink is obtained after reflux and dilution.

[0083] A mixture of dehydrated lead(II) acetate, zirconium(IV) butoxide and titanium(IV) isopropoxide in 2-methoxyethanol with 10% excess lead is heated at reflux during two hours to ensure homogenization and stabilization of alkoxide species via ligand exchange. The resulting PZT sol is then diluted to 0.2 M with ethylene glycol and glycerol to adjust ink viscosity and surface tension for efficient droplet ejection. For instance, the PZT can be diluted in 65 vol % 2-methoxyethanol, 25 vol % glycerol and 10 vol % ethylene glycol.

[0084] Other equivalent processes can be used to obtain the various compositions of ink discussed above.

[0085] FIG. 3 shows an example of pattern/template and a particular printing process according to an embodiment of the invention. A grid-like pattern is printed with SAMs (step (a) of the printing process). In practice, a first series of parallel lines is printed and then a second series of parallel lines perpendicular to the first series is printed. Then the functional material is printed within the boundaries of the grid-like pattern (step (b) of the printing process).

[0086] In a particular example, the steps of drying, pyrolysis and crystallization are applied to obtain a final (dry) film on the substrate, as illustrated on the right side of FIG. 3.

[0087] In a particular example of a product obtained by the invention, the two-step full-inkjet-printing process has been used to fabricate an array of 500×500 μm.sup.2 PZT squares. The obtained 80 nm-thick structures are crystallized in perovskite phase.

[0088] FIG. 4 shows pictures taken with an optical microscope of the films that can be obtained after multi-layer printing process. The printing steps of FIG. 3 are repeated. They are carried out in the same area of the substrate to build one layer at a time. This means that a precise repositioning of the printing head relative to the substrate for each new layer is performed.

[0089] FIG. 5 shows the thickness profile of one of the squares. The measurement of the thickness was made after crystallization of each of the successive layers and prior to printing the next layer. We can see regular thickness along the transverse direction of the square. We can also see that the method of the invention allows a precise positioning of the layers one onto each other. Of course, by varying the density of droplets from one layer to another layer, or varying the functional material, a wide variety of heterogenous products can be printed.

[0090] FIG. 6 shows the results of the SIMS analysis (imaging mode) of a film realized with the printing method of the invention. An elemental mapping of titanium, oxygen and sulfur was performed in the edge area of a printed PZT square. Sulfur was mostly detected at the edge of the PZT square.

[0091] Both the functional material and the SAM precursor inks were liquid and were in contact with each other during the printing process. The sulfur detected in the layer of functional material can only originate from thiols that have diffused into the functional material precursor ink while both were in liquid state. Such diffused sulfur is not observed when SAMs are deposited by any other method because in these known methods, the liquid functional material ink is only printed once the SAM is formed and there is no residual liquid on the substrate.

[0092] Although the printing process, the composition of the SAM, the composition of the functional material, the substrate material and the cartridges have been described in details in separate paragraphs of the description, it has to be noted that each particular embodiment of one of these elements is combinable with each particular embodiment of another one of these elements.