JPS59178681A - Pattern forming method - Google Patents

Abstract

PURPOSE:To prevent corrosion of a conductor pattern at a washing time by exposing an Al alloy metallic film to plasma containing oxygen before the Al alloy metallic film is brought into contact with washing water. CONSTITUTION:Between the etching process and the washing process of a conductor pattern 4, the conductor pattern 4 is exposed to oxygen plasma or air plasma to oxidize the side face of the conductor pattern 4 formed with etching, and an alumina film 42 is formed. As the result, when the pattern 4 is washed in the washing process, the oxidized film 42 is not corroded by washing water, and the pattern 4 is not corroded.

Description

Detailed Description of the Invention Ta1 Technical Field of the Invention The present invention relates to the manufacturing process of magnetic bubble memories, etc.
The present invention relates to a method including a step of patterning an aluminum-based alloy film, and more particularly relates to corrosion prevention of an aluminum-based alloy film.

(Background of BL technology Figure 1 is a cross-sectional view showing the layer structure of magnetic bubble memory.
An insulating layer 3a made of SiOr is provided on a bubble magnetic film 2 formed on a GG wafer 1 by liquid phase epitaxial growth, and a conductor pattern 4 made of ^1-Cu (CuO, 5 to 2%) is formed thereon. has been done. After providing an insulating layer 3b of StO2 on the conductor pattern 4 again, a permalloy pattern 5 is patterned and finally coated with an insulating N3c made of 5iOz or synthetic resin.

(c) Prior art and its problems As described above, the conductor pattern 4 is made of Al-Cu, but films of aluminum-based alloys such as 81-Cu are easily corroded during the cleaning process, and therefore the conductor pattern 4 is made of Al-Cu. This may adversely affect the characteristics of the product. FIG. 2 is a cross-sectional view showing a conventional conductor pattern creation process. First, as shown in (a), an Al--Cu film 41 is deposited on the SiOr insulation 1ii3a by vapor deposition or spankling. Next, a photoresist 6 is coated and dried as shown in (b), then exposed using a mask 7 as shown in (c), and developed as shown in (d) to form a photoresist pattern 61. This photoresist pattern 6 as shown in (e)
1 as a mask using techniques such as ion milling to remove Al-C.
When the U film 41 is etched, the area without the photoresist L-layer 61 is etched away, and the Al-Cu film 41 is etched away.
A conductor pattern 4 is formed. Next, after cleaning with ultrasonic waves in pure water or acetone, the resist pattern 61 is removed as shown in (1), and cleaning is performed again as shown in (h).

Then, the next SiO2 layer 3b is deposited.

In this way, the Al-Cu conductor pattern 4 is
Since the conductor pattern 4 is cleaned in the cleaning process, the surface of the conductor pattern 4 on which the pattern has been formed is corroded by the cleaning water. Also, in the cleaning step (f), the side surfaces of the conductor pattern 4 come into contact with the cleaning water and corrode.

(d1 Purpose of the Invention) The present invention aims to eliminate such problems during conventional conductor pattern formation and to prevent corrosion of the conductor pattern during cleaning.

(e) Structure of the Invention The technical means according to the present invention taken to achieve this object is a method of obtaining a predetermined pattern by puncturing an aluminum alloy film deposited by a method such as spanking or vapor deposition. In this method, the aluminum-based alloy film is exposed to oxygen-containing plasma before the aluminum-based alloy film comes into contact with cleaning water.

(f) Examples of the Invention Next, examples will be used to explain how the pattern forming method according to the invention is actually implemented. FIG. 3 is a sectional view showing the pattern forming method according to the present invention in the order of steps, and the same steps as in the conventional pattern forming method of FIG. 2 are denoted by the same reference numerals. That is, the steps from (a) to (b) for etching the conductor pattern are the same as the conventional structure.

In the method of the present invention, between the conductor pattern etching step (e) and the cleaning step (g), the side surfaces of the conductor pattern 4 formed by etching are oxidized by exposing them to oxygen plasma or air plasma. , an alumina film 42 is formed. The aluminum oxide film has excellent corrosion resistance, so even if it is cleaned in the cleaning process (g), the oxide film 42 will not be corroded by the cleaning water. When 61 is removed, the upper surface 43 of the conductor pattern 4 is exposed, so in order to prevent the upper surface 43 from being corroded in the next cleaning step, it is exposed to oxygen plasma or air plasma in the same way as in the previous case. By exposing, a certain oxide film 44 is formed. Note that when removing the resist pattern 61 by incinerating the resist pattern 61 using a plasma dry asher, the resist pattern 61 is removed by 1 to 2 steps after ashing.
The upper surface 43 of the conductor pattern 4 is protected by the oxide film 44 by leaving it in the plasma atmosphere Gj for about an hour, and then cleaning is performed in the cleaning step (v).

Although the oxide film formation 5- is carried out in the two steps (He) and (B), it is also effective to form the oxide film only once in the step (S). That is, since the area of the upper surface 43 is much larger than the serum on the side surface of the conductor pattern 4, even if the side surface is corroded, the conductor pattern as a whole is not affected much.

In such a case, the corrosion prevention treatment on the side surface in the step (f) is not performed, and the oxide film 44 is formed on the second surface 43 in the step (s), and the corrosion prevention treatment on the top surface 43 is not performed in the step (v). Prevent corrosion.

In addition, immediately after depositing the Al-Cu film 41,
By forming an oxide film on the entire surface of the Al-Cu film 41, it is possible to prevent corrosion of the Al-Cu film 41 not only in the cleaning process but also in the photoresist 6 coating process and the subsequent ethoching process. Effective when performing chemical etching. Furthermore, (l11) in the theft process
It will be perfect if an oxide film is also formed on one surface. □ +g1 Effect of the invention As described above, according to the present invention, when the film of an aluminum alloy such as Al-Cu comes into contact with cleaning water, before the point 6-, the film of an aluminum alloy such as Al-Cu is exposed to oxygen plasma. An oxide film is formed on the exposed surface by exposing it to oxygen-containing plasma such as air plasma.

Since the conductor pattern is coated with a highly corrosion-resistant oxide film and then cleaned, it is possible to prevent the conductor pattern from being corroded by cleaning water and deteriorating its characteristics as a conductor pattern as in the conventional case.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a magnetic bubble memory, FIG. 2 is a sectional view showing a conventional pattern forming method in order of steps, and FIG. 3 is a sectional view showing an embodiment of a pattern forming method according to the present invention in order of steps. In the figure, 4 is a conductor pattern, 41 is 8 l-C
42 and 44 are the oxide films, and 43 is the upper surface of the conductor pattern, respectively. Patent Applicant: Fujitsu Limited Agent, Patent Attorney: Minoru Aoyagi 7- Figure 1, Figure 2, Figure 3

Claims (1)

[Claims] In a method for obtaining a predetermined pattern by patterning an aluminum-based alloy film deposited by a method such as spanking or vapor deposition, before the aluminum-based alloy film comes into contact with cleaning water, A pattern forming method characterized by exposing the aluminum alloy film to plasma containing oxygen.