DD264418A1 - METHOD FOR IMPROVED MANUFACTURE OF FINE TO MICROSTRUCTURES - Google Patents

Abstract

The invention relates to a method for the improved production of fine to microstructures and can be applied in the technologies for holo-gratings, split optics, thin optical layers and electronic components. The object of the invention is to produce sharp and defined structures by improved adhesive properties of a photosensitive layer on a substrate by technologies of the semiconductor industry, the purpose of which is to modify the surface of a substrate in such a way that the improved adhesion behavior occurs. The object is achieved by a layer sequence of metal oxide, in particular Al 2 O 3, metal and photosensitive layers is produced on the substrate, wherein the oxide layers mediate better bonding by hydrogen bonds. Fig. 1

Description

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Field of application of the invention

The method according to the invention can be used in the technologies for holo-gratings, split optics, thin optical layers and electronic components.

Characteristic of the known technical solutions

There are known methods, photosensitive layers on substrates of z. As glass or Chromoxld- / chrome layers and processed by further processing by exposure, development, evaporation and etching or lift-off technology to stencils and other semi-finished products.

The disadvantages of these methods are that the adhesion of the photosensitive layers is not homogeneous over larger surface areas. On polished substrates made of glass, the surfaces are not characterized by the polishing process by uniformly distributed, chemically similar structures. Depending on acidic or alkaline cleaning media and the inhomogeneous glass composition, uniform adhesion of the photosensitive layer is not possible. The result is a certain edge roughness of the photolithographically generated structures.

In the case of inorganic crystals as a substrate, the adhesion of the photosensitive layers is also hindered, since adhesion-bridging hydrogen bonds are lacking.

This aspect is also true for chrome layers. An extremely thin chromium layer as Haftverml.iler leads to the reduction of the transmission of the substrate.

In DE-OS 1948141 a process is described where 1 to 1.8 nm thick Al ₂ O ₃ flames are produced for the purpose of improving the adhesion of MgF ₂ to PMMA-Linsan. In DE-OS 3029051, a chromium layer is coated with an oxide skin in order to lower the noise level of the layer systems.

Furthermore, methods for producing different layer systems for universal optical purposes are known. The AI ₂ O ₃ layer used in this case is used, inter alia, to delineate the high oxidation potential of the CeO ₂ -AtZmHtOIs and generally to protect against corrosion.

Other applications are known from the stabilization of very thin layers. The Al ₂ O ₃ layers used for this purpose are used for improved separation behavior of surfaces or as a capacitor and not for producing a punctiform adhesion in the atomic range on polished substrates.

Object of the invention

The aim of the invention is a process for the improved production of fine to microstructures in which sharp, defined structures are formed by improved adhesion of a photosensitive layer to a substrate by means of etching or lift-off technology.

Explanation of the essence of the invention

The invention has for its object to modify the surface of a substrate so that a large-scale, homogeneous adhesion of the photosensitive layer achieved and redox potentials are made ineffective.

This object is achieved by a method for the improved production of fine to microstructures according to the invention by applying at least one thin Al ₂ O ₃ -SchAhI between the substrate and the photosensitive layer depending on the material of the substrate or later intended use.

On a substrate of polished glass or crystal, after application of a luminescent cleaning process to a discharge current of 6 A and a duration of 3 to 5 minutes, a 2 to 6 nm thick aluminum layer is applied at a rate of 0.2 to 0.6 nm / s and a pressure of 5 , 33 10 ' ⁴ Pa evaporated and immediately after three times rinsing of the recipient to 13.33Pa in an atmosphere of molecular oxygen in a pressure range of 13.33 to 1.333 and an acceleration voltage less than 3KV inside SmIn glowing tent and 6min impact tingling gelled.

Depending on the intended use of the structures, a thin layer of chromium is then vapor-deposited on the layer of Al 2 O 3 or the photoimageable layer to be exposed is applied immediately by known methods. The first case is followed by a second cycle to produce a thin Al ₂ O ₃ layer under the same conditions. This is followed by coating with photosensitive material. The photolithographic processing is carried out according to generally customary exposure to UV light or holographic processes.

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The inventive method will be explained in more detail with reference to the examples shown in the drawing

 Show it:

Fig. 1: the method using the llft orf technology, Fig. 2: the method using the etching technology.

In Flg. 1, a thin Al ₂ O ₃ layer 2 is applied to a substrate 1. Then a layer of fotoer.ipf indllchem Material 3 applied, exposed and developed according to known methods. The relief formed in the photosensitive material is coated with a suitable metal layer, preferably chromium

or nickel, coated and the unnecessary parts of the photosensitive material 3 together with the MetPüschicht 4 detached. The

remaining metal layer 4 learn through the thin Al ₂ O ₃ layer 2 a special liability with this and thus the substrate

In Figure ₂ , a thin Al ₂ O ₃ layer 2 is first generated on a substrate 1, followed by a thin chromium layer

4 is evaporated. Dle? E is immediately afterwards mixed with a two-Al ₂ O ₃ -SChICb *. i ' covered. Onto this layer system, the photosensitive material 3 is applied, exposed and developed by known methods.

The structures in the chromium layer 4 are produced in an etching bath (not shown).

Claims (2)

1. A process for the improved production of fine to microstructures, in which a layer sequence of metal oxide, metal and photosensitive layers is present on a substrate, characterized in that a layer sequence is applied on a substrate after the steps listed below: a) Smoldering of a Substratoberflöche at 6A discharge current and 3 to 5min duration b) deposition of a 2 to 6 nm thick aluminum layer on a substrate surface at a rate of 0.2 to 0.5 nm / s and a pressure of 5.33 x 10 ^"4 Pa c) rinsing the recipient with argon to 1.33 Pa z. 3 times d) Oxidation of the dry aluminum layer in molecular oxygen at 13.33 Pa to 1.333 Pa, less than 3 KV acceleration voltage, 5 min glow time and 5 min exposure time e) applying a thin chromium layer f) applying a second 2 to θ nm thick aluminum layer under the same conditions as b) g) oxidation of the second thin aluminum layer under the same conditions as d) 2. The method according to item 1, characterized in that on a substrate, the layer sequence of an aluminum oxide layer on which a photosensitive layer is arranged exists.