JPS6022429B2 - How to create integrated devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an integrated device such as a cylindrical magnetic domain (bubble) device or a semiconductor integrated circuit, which eliminates the step difference.

In the Kuzutsu Shigeru element, a soft magnetic material (usually a permalloy pattern) is usually created on a bubble crystal film (garnet, etc.), and the bubbles are moved using the magnetic material pattern as a guide. The so-called functional part that generates and eliminates bubbles, changes the transfer path, or divides the bubbles into two or more multiple paths and transfers them is a conductor wired between the magnetic material pattern and the crystal. Contains a pattern. These functions are performed by passing current through the conductor pattern and using the generated magnetic field. Generally, in a functional part, a part of the magnetic material pattern is also arranged on the conductive pattern. For this reason, the magnetic material pattern is affected by the step difference in the conductor pattern, and if the step is steep, the magnetic coupling between the magnetic material patterns spanning the conductor pattern becomes weaker, which deteriorates the operating characteristics of each functional section. Furthermore, there are steps in integrated elements such as semiconductors, and circuit breakage may occur at such steps. For this reason, various proposals have been made to eliminate the level difference. In a cylindrical magnetic domain element, the conductor pattern is a conductor film (for example, A↓ AZ-Cu, etc.)
After vapor deposition, a conductor pattern is formed using a positive resist.

That is, the film other than the pattern portion is removed by etching. Thereafter, the resist is peeled off, and an insulating layer and a European magnetic material (for example, Permalloy) for transfer are deposited. Therefore, a step in the thickness of the conductor is created at the boundary between the conductors, and in order to reduce this step, attempts have been made to make the thickness of the conductor as thin as possible or to control its shape by controlling the etching conditions. .
However, there is a limit to making the conductor thinner, and controlling the shape through etching conditions does not essentially eliminate the step difference. Another method is to spin-coat a thermosetting inorganic polymer such as water glass after forming the conductor pattern to reduce the 7-percent corner of the step.

Although this method reduces one corner of the taper, it does not essentially eliminate the step difference, and there are also problems such as cracking due to the adhesiveness of the applied polymer and the difference in thermal expansion coefficient with the substrate. Yet another method is to embed the conductive pattern with an insulating layer. For example, after depositing an insulating film uniformly on a crystal, masking it with resist and digging a groove for a conductor pattern by etching, a conductor with a thickness corresponding to the depth of the groove is deposited, and the buried conductor is removed by lift-off. Methods of creating patterns are known. However, the problem with the lift-off method is that
A film may adhere to the sidewalls of the resist pattern, making it difficult to remove the resist. For this reason, attempts have been made to make the side walls of the resist pattern steeper by applying a thicker resist or using a positive resist. SUMMARY OF THE INVENTION An object of the present invention is to provide a new method for producing integrated devices such as cylindrical magnetic domain devices and semiconductor integrated circuits without steps.

That is, in the process of producing an integrated device, the present invention etches a film to be etched using a resist pattern as a mask, then continues to deposit an insulating film to a thickness greater than the thickness of the film to be etched without peeling off the mask, and then etches the film to be etched using a resist pattern as a mask. This method includes at least one planarization step of removing the insulating film attached to the sidewalls of the mask pattern by etching and then peeling off the mask pattern.

The present invention will be explained mainly regarding a cylindrical element with reference to the drawings. FIG. 1 shows a conductor pattern created by a conventional method, and the resist has not been peeled off. The tortoise in the figure is a bubble crystal, 2 is a single layer of substrate, 3 is a conductive pattern, and the tortoise is a mask resist. To create the conductor pattern 3, chemical etching or dry etching such as ion milling is used. The thickness of the mask 4 is preferably lAw or more. Second
The figure shows a state in which an insulating film 5 is deposited on the pattern of FIG. 1 by vapor deposition or sputtering to a thickness greater than that of the conductor 3.
The insulating film 6 may also adhere to the sidewalls of the mask 4. The insulating film 6 on this side wall is removed by one of the following methods. 1. Ion milling method using an obliquely incident beam: As shown in FIG. 3, the sample 7 is fixed on an evening table 9 that is inclined at an angle of {circle around (2)} from the incident beam direction 8.

It is desirable that the incident angle (2) be set at an angle between 45 degrees and 80 degrees, and the purpose of making the beam incident obliquely in this way is to reduce the effect of reattachment to the side wall. In the case of the ion milling method, the thickness of the insulating film 5 is preferably approximately equal to the thickness of the conductor. 2 Plasma etching method: When silicon dioxide (Si02) is used as the insulating film, plasma etching can be used.

At this time, it is desirable that the thickness of the insulating film 5 in FIG. 2 be set to the sum of the thickness of the conductor 3 and the thickness of the insulating film 6 on the side wall. That is, the thickness of the insulating film 5 is made to be the same as the thickness of the conductor 3 when the sidewall Atsushi film 6 is etched. 3. Chemical etching: When alumina (A-203) is used as the insulating film, chemical etching with hot phosphoric acid solution is possible.

In this case as well, it is desirable to set the initial thickness of the insulating pus 5 so that the thickness of the insulating film 5 becomes the thickness of the conductor 3 when the lateral crab insulating pus 6 is removed. After removing the insulating film 5 on the side wall by any of the above methods, the resist 4 on the conductor is peeled off with a remover, and then the insulating film and the soft magnetic material for the transfer pattern are attached, thereby producing a cylindrical magnetic domain element that eliminates the step difference. can get. Furthermore, since the conductor pattern is embedded with an insulating film, damage to the conductor pattern when removing the resist is reduced.

As explained above, according to the present invention, an integrated device without steps can be easily created, the operating characteristics of a cylindrical device can be improved, and the effect of eliminating circuit disconnection can be achieved in general integrated devices such as semiconductors. have

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a state in which a conductor pattern is formed using a resist mask, Fig. 2 is a cross-sectional view showing a state in which an insulating film 5 is attached on the component shown in Fig. 1, and Fig. 3 is an oblique view. 1 is a schematic diagram showing a method of ion millilithography using an incident beam; FIG. 1... Bubble crystal, 2... Baser layer, 3...
Conductor pattern, 4... Resist mask, 5... Insulating film, 6... Insulating film attached to side wall of mask, 7...
Sample, 8...Incoming beam, 9...Turn full. O diagram O 2 diagram Sai 3 diagram

Claims (1)

[Scope of Claims] 1. In the process of producing an integrated device, a film to be etched is etched using a resist patterner as a mask, and an insulating film is continuously deposited to a thickness greater than the thickness of the film to be etched without peeling off the mask. A method for producing an integrated device, comprising at least one planarization step of removing an insulating film attached to a side wall of the mask pattern by etching and then peeling off the mask pattern. 2. The method of manufacturing an integrated device according to claim 1, wherein the integrated device is a cylindrical magnetic domain device, and the film to be etched is a conductive film. 3. The method of manufacturing an integrated device according to claim 1 or 2, wherein etching of the insulating film attached to the side wall of the mask pattern is performed by an ion milling method using an obliquely incident beam. 4. Etching of the insulating film attached to the side wall of the mask pattern is performed by plasma etching method.
A method for producing an integrated device according to item 1 or 2. 5. The method of manufacturing an integrated device according to claim 1 or 2, wherein the insulating film attached to the side wall of the mask pattern is etched by a chemical etching method.