METHOD FOR PRODUCING A ROLLED-UP ELECTRICAL OR ELECTRONIC COMPONENT

Abstract

The present invention relates to the fields of physics, material sciences and micro and nano electronics, and concerns a method for producing a rolled-up electrical or electronic component, as can be used for example as a capacitor, or in aerials. The object of the present invention is to provide a low-cost, environmentally friendly and time-saving method for producing a rolled-up electrical or electronic component with many windings. The object is achieved by a method for producing a rolled-up component in which at least two functional and insulating layers, alternately arranged fully or partially over one another, are applied to a substrate with a sacrificial layer, wherein at least the functional or insulating layer that is arranged directly on the sacrificial layer has a perforation, at least on the two sides that are arranged substantially parallel to the rolling direction.

Claims

1. A method for producing a rolled-up component in which at least two functional and insulating layers alternately arranged fully or partially over one another are applied to a substrate having a sacrificial layer, wherein at least the functional or insulating layer that is arranged directly on the sacrificial layer comprises a perforation at least on the two sides that are arranged essentially parallel to the rolling direction.

2. The method according to claim 1 in which the perforation is composed of a rib-like structuring and the ribs have a basic quadrilateral shape.

3. The method according to claim 2 in which, for the basic quadrilateral shape of the ribs, one of the sides of the ribs is arranged essentially parallel to the rolling direction of the layers and is part of the edge of the layer to be rolled up and has a lateral length (B) of 1 to 1000 μm, and the other side of the ribs essentially parallel to the rolling direction of the layers is arranged at a distance (H) of 5 to 200 μm from the edge of the layer to be rolled up, and the distance between the ribs is 20 to 4000 μm, and the angle (α) between the side of the ribs that is first in the rolling direction and the edge of the layer to be rolled up outside the rib is between 15° and 135°, and the angle (β) between the side of the ribs that is last in the rolling direction and the edge of the layer to be rolled up outside the rib is between 45° and 135°, and subsequently the sacrificial layer is fully or partially removed and the layer stack is rolled up.

4. The method according to claim 1 in which a rigid or flexible material is used as a substrate.

5. The method according to claim I in which a substrate of silicon, silicon oxide, glass, ceramic, or a film of poly(ethylene terephthalate) (PET) or polyether ether ketone (PEEK), and a sacrificial layer of poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), biopolysaccharides, cellulose acetate, poly(allylamine) (PAH), methylcellulose or ethylcellulose are used.

6. The method according to claim 1 in which, as functional layers, layers of an electrically conductive material and, as insulating layers, layers of a dielectric and/or electrically insulating material are applied by means of atomic layer deposition and/or chemical vapor deposition.

7. The method according to claim 1 in which a layer stack is applied to the sacrificial layer, which layer stack is composed of a layer of at least one dielectric and/or electrically insulating material, a layer of at least one first electrically conductive material, an additional layer of at least one dielectric and/or electrically insulating material, and a layer of at least one second electrically conductive material, and in which layer stack the layers of the dielectric and/or electrically insulating material essentially completely cover the layers of the electrically conductive material.

8. The method according to claim 6 in which Ti, Cr, Al, Au, Ni, Pd, Cu, W, Ta and compounds thereof, or indium tin oxide or highly doped semiconductor material are used as material for electrically conductive layers.

9. The method according to claim 1 in which AlO.sub.x, advantageously Al.sub.2O.sub.3, SiO.sub.x, advantageously SiO.sub.2, AlTiO.sub.x, SiTiO.sub.x, HfO.sub.x, TaO.sub.x, ZrO.sub.x, HfSiO.sub.x, ZrSiO.sub.x, TiZrO.sub.x, TiZrWO.sub.x, TiO.sub.x, SrTiO.sub.x, PbTiO.sub.x, SiAlO.sub.x, metal nitrides such as aluminum nitrides AlN.sub.y, silicon nitrides SiN.sub.y, AlScN.sub.y, metal oxynitrides such as aluminum oxynitrides AlO.sub.xN.sub.y, silicon oxynitrides SiO.sub.xN.sub.y, HfSiO.sub.xN.sub.y and/or SiC.sub.zO.sub.xN.sub.y are used as material for dielectric and/or insulating layers.

10. The method according to claim 1 in which at least one layer that is applied directly to the sacrificial layer has a rolling-up length of 1 mm to 30 mm.

11. The method according to claim 1 in which the functional and insulating layers are arranged over one another on the sacrificial layer, which functional and insulating layers comprise on both sides parallel to the rolling direction the same rib-like structuring with regard to the number and geometry of the ribs.

12. The method according to claim 1 in which functional and insulating layers are applied in which the side of the ribs that is arranged essentially parallel to the rolling direction of the layers and is part of the edge of the layer to be rolled up has a lateral length (B) of 10 to 200 μm.

13. The method according to claim 1 in which functional and insulting layers are applied in which the side of the ribs that is arranged parallel to the rolling direction of the layers and is not part of the edge of the layer to be rolled up, or a corner of the ribs, is arranged at a distance (H) of 10 to 50 μm from the edge of the layer to be rolled up

14. The method according to claim 1 in which functional and insulating layers are applied in which the distance (D) between the ribs in the rolling direction is 20 to 500 μm.

15. The method according to claim 1 in which functional and insulating layers are applied in which the angle (α) between the side of the quadrilateral of the ribs that is first in the rolling direction and the edge of the layer to be rolled up outside the quadrilateral is between 30° and 120°, more advantageously 45°, and the angle (β) between the side of the quadrilateral of the ribs that is last in the rolling direction and the edge of the layer to be rolled up outside the quadrilateral is between 80° and 120°, more advantageously 90°.

16. The method according to claim 1 in which the sacrificial layer is removed by means of etching or using organic solvents and/or water and/or ethylenediaminetetraacetic acid.

Description

[0058] The invention is explained below in greater detail with the aid of several exemplary embodiments.

[0059] Wherein:

[0060] FIG. 1a shows a layer to be rolled up, according to the prior art

[0061] FIG. 1b shows a layer to be rolled up, with a perforation

[0062] FIG. 2a shows a diagram of the rolling process for a layer according to the prior art

[0063] FIG. 2b shows a diagram of the rolling process for a layer with a perforation

EXAMPLE 1

Capacitors

[0064] For the production of an ultra-compact microcapacitor having a plurality of coils, a layer of methylcellulose was spun in a centrifuge at a rotational speed of 4500 rpm (revolutions per minute) in a completely covering manner onto a silicon substrate with a length of 20 mm and a width of 5 mm with a 1-μm thick thermally applied silicon dioxide layer, and was subsequently baked and dried on a hot plate for 5 minutes at 120° C. This layer of methylcellulose, which was thinner than 5 nm, was the sacrificial layer.

[0065] Then, using the method of atomic layer deposition, an 11-nm thick Al.sub.2O.sub.3 layer was deposited at 150° C. such that it completely covered the sacrificial layer. This Al.sub.2O.sub.3 layer, which acts as a dielectric, also serves as an insulation layer between the two metallic electrodes following the rolling-up and as protection for the sacrificial layer against the subsequent process steps and air humidity.

[0066] With the aid of optical photolithography, the first electrode of the capacitor was structured with a length of 10 mm in the rolling direction and a width of 0.6 mm. By means of electron beam evaporation, a tensioned electrically conductive layer composed of 15 nm Ti and subsequently 20 nm Cr were deposited each at a rate of 0.1 nm/s and subsequently lifted off. The layer comprised a perforation with ribs having a basic quadrilateral shape on both sides of the layer parallel to the rolling direction and was achieved using a mask during the deposition of the layer. The perforation was composed on both sides of geometrically identical and equally sized ribs, was adapted to the expected rolling diameter of 50 μm, and had the following dimensions:

[0067] Height of the ribs: H=9 μm,

[0068] Width of the ribs at the edge of the layer: B=25 μm,

[0069] Distance between the ribs at the edge of the layer: D=25 μm,

[0070] First angle in the rolling direction: α=21°,

[0071] Second angle in the rolling direction: α=78°.

[0072] Then, a second 11-nm thick Al.sub.2O.sub.3 layer was once again deposited by means of atomic layer deposition at 150° C. such that it completely covered the first electrically conductive layer, albeit without perforation on the sides.

[0073] After optical lithography for the second electrode, the deposition of the second electrically conductive layer, also once again without any rib-like structuring one the sides, of 10 nm Cr took place at a rate of 0.1 nm/s and with a subsequent lift-off. Finally, the protruding sacrificial layer was removed using water, and the tensioned layer stack was rolled up at a speed of 2 mm/min.

[0074] Through the use of the perforation according the invention, it was possible to consistently carry out the rolling-up procedure over the entire rolling-up length across the entire rolling-up front in the rolling direction and at a high rolling-up speed.

[0075] In this manner, it was possible to produce a rolled-up capacitor using a cost-effective, environmentally friendly and time-saving method.

EXAMPLE 2

Antenna

[0076] For the production of a three-dimensional antenna, a layer of a 4% (w/v) diluted poly(acrylic acid) (PAA) was spun at 3000 rpm in a completely covering manner onto a 22×22 mm.sup.2 glass substrate with a thickness of 200 μm. The final layer thickness of this sacrificial layer was 500 nm. This layer was dried at 35° C. for 2 minutes and then immersed in a 1-molar solution of CaCl.sub.2 in deionized (DI) water. The coated substrate was subsequently washed in DI water and dried. By means of standard photolithography, the base surface of the antenna was structured using AR-P3510 photoresist. The PAA sacrificial layer was removed at the uncoated sites using undiluted AR300-35 developer and washed in DI water, The photoresist was removed in acetone, and the coated substrate was washed in isopropanol and dried. A tensioned layer stack of organic materials was applied to this sacrificial layer. The first layer was composed of PAA (M.sub.w=150000) and PVA at a ratio of 1:1, 4% (w/v) diluted in water. The second layer was composed of polyimide (M.sub.w=100000), 2% (w/v) diluted in N-methyl-2-pyrrolidone. The first polymer layer was applied at 8000 rpm to the sacrificial layer over the entire area with a resulting layer thickness of 500 nm. This layer was structured by means of standard photolithography and undiluted developer, wherein the layer comprised on both sides of the layer parallel to the rolling direction the perforation with ribs having a basic quadrilateral shape and the following dimensions:

[0077] Height of the ribs: H=200 μm,

[0078] Width of the ribs at the edge of the layer: B=100 μm,

[0079] Distance between the ribs at the edge of the layer: D=300 μm,

[0080] First angle in the rolling direction: α=45°,

[0081] Second angle in the rolling direction: β=90°.

[0082] The perforation was composed on both sides of geometrically identical and equally sized ribs.

[0083] The deposition of the metal layer on the tensioned layer without perforation followed. For this purpose, the photoresist was structured by means of standard photolithography and Ta(10 nm)/Cu(100 nm)/Ta(10 nm) was deposited by means of magnetron sputtering. During this step, Ar at a partial pressure of 0.1 Pa was used as a sputtering gas. The lift-off took place with acetone and a subsequent rinsing in isopropanol.

[0084] The planar, two-dimensional structures produced in such a manner with a footprint of 5.5×17 mm.sup.2 were rolled up into three-dimensional helical antennas by removal from the substrate. The removal was achieved by means of selective etching of the sacrificial layer in a 0.5-molar ethylenediaminetetraacetic acid (EDTA) solution. After the rolling process, the antennas were washed in DI water and dried in air. The diameter of the rolled-up antenna was 300 μm, and the length after the rolling was 5.5 mm.

[0085] Through the use of the perforation according the invention, it was possible to consistently carry out the rolling-up procedure over the entire rolling-up length across the entire rolling-up front in the rolling direction and at a high rolling-up speed.

[0086] In this manner, it was possible to produce a rolled-up antenna using a cost-effective, environmentally friendly and time-saving method.