JPS58215027A - Formation of pattern according to etching - Google Patents

Abstract

PURPOSE:To facilitate the removal of a low resistivity film pattern by a method wherein the thin film having low resistivity and to have the melting point lower than the pattern forming layer when oxidized is adhered on the surface of the pattern forming layer, while the surface is covered with a resist having the prescribed shape, the exposed thin film and pattern forming layer are etched to be removed, the resist is also removed, and the thin film existing thereunder is oxidized to be evaporated. CONSTITUTION:The Al layer 2 to be used as the pattern forming layer is adhered on the surface of a substrate 1, and the Cr2O3 layer 3 of low resistivity is evaporated thereon. Then the upper part thereof is covered with the resist pattern 4 having the prescribed shape, ion etching is performed to remove the exposed parts of the Cr2O3 layer 3 and the Al layer 2, and the Cr2O3 pattern 3' and the desired Al pattern 2' are left under the pattern 4. After then, the substrate 1 is exposed in O2 plasma not to incinerate Al, the pattern 4 is incinerated to be removed at first, the pattern 3' is exposed directly to O2 plasma, Cr2O3 having the melting point of 1,990 deg.C is oxidized to convert into CrO3 having the melting point of 190 deg.C and is evaporated, and the pattern 2' only is left.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for accurately forming patterns by etching, particularly fine patterns.

(b) Background of the technology In elements with expensive patterns formed by photolithography technology, such as magnetic bubble memory elements, patterns such as bubble transfer paths, bubble generators, and bubble detectors are used to increase the capacity of the element and 1μm due to the pursuit of miniaturization
The following 42 are now required. These element patterns are formed by forming a resist pattern on the surface of a metal layer made of permalloy, At, NiCr, etc., and etching the portions not covered by the resist pattern.

(c) Comparison with the prior art However, since the surface reflectance of the metal layer is high (for example, that of At is over 90%), when it is clearly exposed to form a resist pattern, the light is reflected around the surface. As a result, the resist pattern and, by extension, the clarity of the pattern will be impaired. Therefore, conventionally, a low-reflectance .4 film is deposited on the surface of a metal layer by full evaporation (or sputtering), a resist pattern is formed on the surface of the thin film, and the resist .(
After removing the thin film and gold beak layer not covered by the turns, the resist pattern was removed, and other constituent patterns and a protective layer were formed thereon.

At that time, when the thin film is made of an oxide such as Cr2O3, the way in which 02 is taken in is unstable, and the volume changes due to exchange of 02 with the laminated layer temporarily formed on it. There is. In addition, the remaining 14ff
If the metal pattern affects the four-dimensional characteristics of the metal pattern, the reliability of the device characteristics will be lost, so it is not necessary to remove the thin film pattern by chemical etching when forming the metal pattern. There was something special about it.

(d) Object of the Invention An object of the present invention is to provide a method for forming an etching pattern that eliminates the above-mentioned drawbacks.

(e) Structure of the Invention The above object is to form a pattern by depositing a thin film on the surface of which has a low reflectance and which has a lower melting point when oxidized than the pattern forming film, and to apply a resist to the surface of the thin film. forming a pattern, etching away the exposed parts of the thin film and the pattern forming layer that are not covered by the resist pattern, removing the resist pattern, and etching away the exposed parts of the thin film and the pattern forming layer that are not covered by the resist pattern; This is achieved by a method of forming a pattern by etching, which is characterized in that the pattern is removed by oxidation and evaporation.

(f) Embodiment of the Invention The method of the present invention will be described below using tables and figures for explaining the main steps related to an embodiment of the present invention. -: Shows the main process of forming a turn and the main equipment used in this process.

table The figure is a cross-sectional view of a sample corresponding to the main process.

In Steps a and A of the table, an Ai% (pattern forming layer) 2 with a thickness of 2000 A is deposited on the surface of the substrate 1 using a vapor deposition means.

In the first and second steps, a 200A thick cr 205 layer (low reflectance, grade 4) 3 is deposited on the surface of the AJ2 by vapor deposition means.

Next, in Step C of the table and Figure C, a resist pattern 4 is formed by spinning the resist layer 90 times, exposing and developing it using a general method.

Next, in step d in the table and 2 in the figure, Cr20, which is not treated in the resist pattern 4, is removed using an ion etching and tengu device.
g 'Remove sound 3 and At layer 2, and add CrtO, pattern (pattern 1) and A under resist pattern 4.
t pattern (desired pattern) 2' is formed.

In step e in the table and SVC in FIG. 7r, when the sample shown in 12 is exposed to 02 plasma without Ati ashing using a plasma asher, the resist pattern 4 is first incinerated and removed, and then the Cr2O5 pattern 3' is 0
．． Becomes directly exposed to plasma. As a result, Cr2O3, which has a melting point of about 1990°C, is oxidized and has a melting point of about 190°C.
℃ and evaporates, the Cr2O pattern -3' disappears and only the At pattern 2' remains on the surface of the substrate 1. Note that the above embodiment does not require the A4 layer 2. This is an example in which the At pattern 2' is formed by etching away the etched portion, and is made of permalloy, Au, and NiCr.
Patterns such as the above are also formed by using the same process as the above process and the same pattern as the above.

(2)) According to the uninvented method as described in detail of the invention, a film with low reflectance =i on the surface of the pattern formation 1i for preventing light from going around is oxidized to have a low melting point and removed by evaporation. Therefore, it becomes possible to remove the resist pattern shaped on the surface of the thin film in the same process, and the effect of making the removal of the low reflectance film pattern much easier than in the conventional method is significant.

[Brief explanation of the drawing]

The figure is a cross-sectional view of the main steps of the present invention. In addition, while in jν1, chant 2 Ba At (・ku turn formation,
]). 2”riAL pattern (desired pattern), 3 is Cr2
O3 film (4 layers with low reflection potential), 3' and Cr2O3□'
/ (7: J, (pattern), 4 indicates the resist pattern.

Claims (1)

[Claims] In a method of forming a desired pattern by selectively etching a pattern-forming layer having a thin film of low reflectance on its surface, the surface of the pattern-forming layer has a low reflectance and when etched, the pattern-forming layer has a lower reflectance than that of the pattern-forming layer. , CrzOs
A resist pattern is formed on the surface of the cherry blossom thin film, the exposed portion of the thin film and the pattern forming layer that is not covered by the resist pattern is removed by etching, the resist pattern is removed, and the resist pattern is removed. A method for forming a pattern by etching, characterized in that the thin film pattern formed under the resist pattern is removed by oxidation and evaporation.