Nanostamping method and nano-optical component

Abstract

In an embodiment a nanostamping method includes forming a nanostructure in a layer of optical embossing material on a first carrier substrate by a forming stamp having a nano-relief, wherein the nanostructure comprises a plurality of nano-elevations which are connected via an embossing material base, generating a coated nanostructure by covering the nano-elevations with a filler material layer, wherein the filler material layer and the optical embossing material comprise different refractive indices, applying a second carrier substrate on the coated nanostructure, detaching the first carrier substrate and removing a material of the embossing material base.

Claims

1. A nanostamping method for manufacturing a nano-optical component, the method comprising: forming a nanostructure in a layer of an optical embossing material on a first carrier substrate by a forming stamp having a nano-relief, wherein the nanostructure comprises a plurality of nano-elevations which are connected via an embossing material base; generating a coated nanostructure by covering the nano-elevations with a filler material layer, wherein the filler material layer and the optical embossing material comprise different refractive indices; applying a second carrier substrate to the coated nanostructure; detaching the first carrier substrate; and removing a material of the embossing material base so that the optical embossing material remains in the coated nanostructure.

2. The nanostamping method according to claim 1, further comprising applying a protective coating to a component surface exposed by the material removal of the embossing material base.

3. The nanostamping method according to claim 2, wherein a difference of real parts of the refractive indices of the protective coating and the filler material layer is smaller than 0.1 for a wavelength range from 380 nm to 780 nm.

4. The nanostamping method according to claim 2, wherein a difference of real parts of the refractive indices of the protective coating and the filler material layer is smaller than 0.1 for a wavelength range from 0.78 m to 1.4.

5. The nanostamping method according to claim 2, wherein the protective coating and the filler material layer consist essentially of the same material.

6. The nanostamping method according to claim 2, wherein the protective coating is formed as a spin-on glass layer.

7. The nanostamping method according to claim 1, wherein a difference of real parts of the refractive indices of the layer of optical embossing material and the filler material layer is greater than 0.5 for a wavelength range from 380 nm to 780 nm.

8. The nanostamping method according to claim 1, wherein a difference of real parts of the refractive indices of the layer of optical embossing material and the filler material layer is greater than 0.5 for a wavelength range from 0.78 m to 1.4 m.

9. The nanostamping method according to claim 1, wherein a release layer is arranged between the first carrier substrate and the layer of optical embossing material.

10. The nanostamping method according to claim 1, further comprising planarizing the coated nanostructure before applying the second carrier substrate.

11. The nanostamping method according to claim 10, wherein planarizing the coated nanostructure comprises planarizing that does not cut the nano-elevations of optical embossing material.

12. The nanostamping method according to claim 1, wherein the filler material layer is a spin-on glass layer.

13. The nanostamping method according to claim 1, wherein the second carrier substrate is transparent in a wavelength range from 380 nm to 780 nm and/or from 0.78 m to 1.4 m and/or from 1.4 m to 3.0 m.

14. The nanostamping method according to claim 2, wherein a difference of real parts of the refractive indices of the protective coating and the filler material layer is smaller than 0.1 for a wavelength range from 1.4 m to 3.0 m.

15. The nanostamping method according to claim 2, wherein a difference of real parts of the refractive indices of the protective coating and the filler material layer is smaller than 0.1 for a wavelength range from 0.78 m 3.0 m.

16. The nanostamping method according to claim 1, wherein a difference of real parts of the refractive indices of the layer of optical embossing material and the filler material layer is greater than 0.5 for a wavelength range from 1.4 m to 3.0 m.

17. The nanostamping method according to claim 1, wherein a difference of real parts of the refractive indices of the layer of optical embossing material and the filler material layer is greater than 0.5 for a wavelength range from 0.78 m to 3.0 m.

18. A nanostamping method for manufacturing a nano-optical component, the method comprising: forming a nanostructure in a layer of an optical embossing material on a first carrier substrate by a forming stamp having a nano-relief, wherein the nanostructure comprises a plurality of nano-elevations which are connected via an embossing material base; generating a coated nanostructure by covering the nano-elevations with a filler material layer, wherein the filler material layer and the optical embossing material comprise different refractive indices; applying a second carrier substrate to the coated nanostructure; detaching the first carrier substrate; removing a material of the embossing material base; and applying a protective coating to a component surface exposed by the material removal of the embossing material base.

19. The nanostamping method according to claim 18, wherein a difference of real parts of the refractive indices of the protective coating and the filler material layer is smaller than 0.1 for a wavelength range from 380 nm to 780 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the invention are explained below in connection with figure illustrations. These show, in each case schematically, the following:

(2) FIGS. 1a-1g show the nanostamping method according to embodiments of the invention for manufacturing a nano-optical component.

(3) FIG. 1h shows the final step for a further development of the nanostamping method according to embodiments of the invention and a nano-optical component.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(4) FIG. 1 shows a schematically simplified sectional view of a first carrier substrate (3) made of silicon with a layer of optical embossing material (2), which can be structured by means of a nanostamping method and is also transparent in the wavelength range selected for the application. For the embodiment shown, polymethyl methacrylate, a thermoplastic suitable for hot embossing lithography, is available, which is applied to the first carrier substrate (3) by spin coating of a mixture of thermoplastic and 2 methyoxyethyl acetate as a solvent. After drying and baking of the solvent at, for example 95, a layer of optical embossing material (2) is formed on the first carrier substrate (3) with an average layer thickness of greater than 1 m, which is substantially greater than the structure width of the nanostructure to be applied. In this case, the layer thickness for the optical embossing material (2) is adapted in such a way that large-area forming stamping is possible.

(5) Further FIG. 1a shows a nickel forming stamp (5) with a nano-relief (4) which represents the negative shape of the nanostructure to be formed and has a maximum pitch of 500 nm. The nano-relief (4) is provided with a coating of polytetrafluoroethylene to improve the stamp release.

(6) FIG. 1b shows the nanostamping method step, in which the forming stamp (5) is pressed under high pressure into the optical embossing material (2), which is heated above the glass temperature. As a result, the nanostructure (1) shown in FIG. 1 is formed in the layer of optical embossing material (2), the depth extent of which is determined by the pitch of the nano-relief (4) of the forming stamp (5) and is less than 500 nm. Accordingly, an embossing material base (7) under the nanostructure (1) remains unstructured.

(7) The nanostructure (1) has nano-elevations (6.1, . . . , 6.n) with a high aspect ratio, which are arranged at predetermined lateral spacings below 500 nm and typically below 100 nm. There are periodic sequences of nano-elevations (6.1, . . . , 6.n) and free areas in one or two directions, at least over partial areas, which are formed by the valleys between the nano-elevations (6.1, . . . , 6.n). The period length of these sequences is less than half the wavelength of the intended optical application. In addition, interruptions of the periodic sequence are present at predetermined positions, which serve to adjust the optical bandgap.

(8) FIG. 1d shows a filler material layer (9) applied to the nanostructure (1), covering the nano-elevations (6.1, . . . , 6.n) and filling the valleys between them, thus forming a coated nanostructure (8). Silicon dioxide is used as the filler material layer (9), which is applied as a spin-on glass layer. The spin-on coating results in a flat surface of the coated nanostructure (8), which can be further levelled by a mechanical-chemical planarization process not shown in detail.

(9) FIG. 1e shows the application of a second carrier substrate (10) of quartz glass on the coated nanostructure (8) by means of anodic bonding, so that a detachment of the first carrier substrate (3) shown in FIG. 1f can be carried out. For this purpose, a layer of a positive resist removable by means of a basic solution is provided as a release layer (13) between the layer of optical embossing material (3) and the first carrier substrate (3). After removal of the first carrier substrate (3), the embossing material base (7) is accessible from the rear side and can be removed by means of an oxygen plasma treatment.

(10) The result of the plasma etching shown in FIG. 1g illustrates the complete removal of the embossing material base (7) so that the nano-elevations (6.1, . . . , 6.n) are separated from each other and form a free-floating nanostructure (1) in the filler material layer (9).

(11) For a further development shown in FIG. 1h, a protective coating (12) consisting of silicon dioxide and thus of the same material as the filler material layer (9) is applied to the surface of the coated nanostructure (8) exposed by the material removal of the embossing material base. The silicon dioxide is applied as a spin-on glass layer.

(12) Further embodiments of the invention within the scope of the following claims are conceivable.