JPH03256325A - Forming method for micropattern - Google Patents

Abstract

PURPOSE:To form a micropattern with high reproducibility by depositing a mask material and so depositing plural times at different angles as to eliminate other shaded part. CONSTITUTION:After a base 11 is coated with resist 12, it is coated with resist 13. A reversed taper-shaped slit 14 is patterned by far ultraviolet ray contact exposure. Then, an Al film 15 as a mask material is deposited from obliquely at an angle theta1 to the vertical direction by an electron beam depositing method. Thereafter, an Al film 18 as a mask material is also deposited from obliquely at an angle theta2 to the vertical direction by an electron beam depositing method. Subsequently, the films 15, 18 in which the resist 12 of the edge of the pattern of the resist 13 is obliquely deposited as mask materials to be used as masks, it is etched vertically under high anisotropy condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of forming a fine slit-like pattern in a manufacturing process of a semiconductor device.

(Prior Art) Conventionally, as a technology in this field, for example, Japanese Patent Application No. 63-232699 filed by the applicant of the present application,
Some have already been proposed.

FIG. 2 is a cross-sectional view of such a conventional fine pattern forming process.

First, as shown in FIG. 2(a), a material layer 2 is placed on a substrate l.
After continuously applying the resist 3, a reverse tapered slit 4 having a width of about 0.5 μm is patterned on the resist 3 by a light exposure method or the like.

After forming this pattern, as shown in FIG. 2(b), an A1 film 5 as a vapor deposition mask material is vacuum-deposited from a direction forming a certain angle θ with the direction perpendicular to the substrate 1. Then, a shadow portion 6 of the vapor deposition mask material in which the slit is to be formed appears within the slit 4.

Therefore, as shown in FIG. 2(c), slits 8 are formed in the material layer 2 in the shadow area 6 by performing anisotropic etching using the Al film 5 as the vapor deposition masking material as a mask. to form fine patterns.

(Problem to be Solved by the Invention) However, according to the conventional method for forming fine patterns described above, it is difficult to control the inverted tapered slits 4 in the pattern of the resist 3, and if the Taber angle becomes large, ,^ff1l15, there is another unplanned shadow part 7 that is not covered with the Affi film 5 on the opposite side of the slit pattern. Therefore,
When the material layer 2 is anisotropically etched, there is a problem in that other shaped portions 7 other than the shadow portion 6 are also etched at the same time.

In addition, in order to form a finer pattern, when the deposition angle θ of the Affi film as a mask material was made smaller, other shadow areas that were not covered by the Al film as a mask material were also generated, which was a problem. .

The present invention eliminates the above-mentioned problems and forms a fine pattern with good reproducibility by performing vapor deposition multiple times at different angles to eliminate the other shadow areas in the process of vapor-depositing the mask material. The purpose of the present invention is to provide a method for forming fine patterns that allows for the formation of fine patterns.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for forming a fine slit-like pattern in the manufacture of semiconductor devices, in which a fine slit-like pattern is formed on a substrate. forming a material layer; forming a resist layer on the material layer; forming a reverse tapered slit in the resist layer to selectively expose the material layer; and perpendicular to the substrate. a step of vacuum depositing a plurality of mask materials at a plurality of tilted angles to cover the entire surface of the material layer except for a planned shadow portion; The layer is dry-etched to form a fine pattern.

(Function) According to the present invention, as described above, even if a shadow portion appears in a portion other than a predetermined portion where a fine pattern is to be formed, a plurality of mask materials are vacuum-deposited at different angles.
The portion can be completely covered with the mask material, and a desired highly accurate fine pattern can be formed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a fine pattern forming process showing an embodiment of the present invention.

First, as shown in FIG. 1(a), a 0DUR resist (manufactured by Tokyo Ohka) 12 was applied to a thickness of 4000 mm on a semi-insulating gallium arsenide substrate 11, and then L? IR
A resist (manufactured by Fuji Pharmaceutical Co., Ltd.) 13 is applied to a thickness of 4000 mm. Then, by deep ultraviolet (Deep [IV)] contact exposure, the width of the upper opening was 0.5 μm.
A reverse tapered slit 14 is patterned. The angle (ω) of the corner of the reversely tapered LMR resist is approximately 60″.

Next, as shown in FIG. 1(b), a
Fl! No. 15 is deposited to a thickness of 3000 mm by electron beam evaporation from an oblique direction at an angle θI (20') with respect to the vertical direction. As a result, the Affi film 15 film shape 5/5 16 appears, and another shadow part 17 appears in the opposite corner of the shadow part 16.

Next, as shown in FIG. 1(c), A
The L film 18 is also deposited to a thickness of 300 mm by electron beam evaporation from an oblique direction at an angle θ2 (50°) with respect to the vertical direction. As a result, the Al film 18 is also deposited on the shadow portion 17 of the Af film 15.

Next, as shown in FIG. 1(d), the LMR resist 1
RIE (Reactive Ion Et.
O! Dry etching is performed vertically under highly anisotropic conditions.

Through the above steps, a slit 1 with a width dimension of approximately 0.15 μm is formed.
9 can be formed.

In this embodiment, in particular, a reverse tapered slit 14 is formed in the LMR registration slot 3, and the first mask material 15,
Both the second mask material 18 is made of A1 film, and LMR
A highly accurate fine pattern can be formed due to the sharp edges of the inversely tapered resist 13.

Note that an insulating film, for example, a Si0g film is used instead of the 0DtlR resist 2 in the above embodiment, and nickel or titanium is used instead of the Al film as the first mask material 15 and the second mask material 18. Alternatively, a combination of these may be used.

FIG. 3 is a cross-sectional view of a fine pattern forming process showing another embodiment of the present invention.

First, as shown in FIG. 3(a), an 0DUR resist 12 is coated on a semi-insulating gallium arsenide substrate as a base 11, and then an LMR resist 13 is coated. Then, by deep ultraviolet contact exposure, a slitter 4 having an inversely tapered opening at the upper end is patterned. This process is the first
This process is similar to the process shown in Figure (a).

Next, as shown in FIG. 3(b), l is used as a mask material.
The film 20 is deposited by electron beam evaporation from an oblique direction at an angle θ with respect to the perpendicular direction.As a result, a shadow area is not generated on the side opposite to the side where the fine pattern is planned to be formed. Affi film 2 is applied to the surface of 0DUR resist 12.
0 film type 0, a fairly wide shadow portion 21 is formed on the side where the fine pattern is planned to be formed.

Next, as shown in Figure 3(c), as a mask material ^
The L film 22 is also deposited by electron beam evaporation from an oblique direction at an angle θ4 with respect to the vertical direction. As a result, a shadow portion 23 of a predetermined width is created on the side where the fine pattern is planned to be formed, and the other portions are covered with the films 20 and 22.

Next, as shown in FIG. 3(d), the LMR resist 1
Using the Affi film 20 film type 02 as a mask material obtained by obliquely depositing the 0DOR resist 12 on the edge portion of the pattern No. 3 as a mask, vertical etching is performed by RIE 08 dry etching under highly anisotropic conditions.

Through the above steps, fine slits 24 can be formed.

FIG. 4 is a cross-sectional view of a main part of forming a fine pattern showing still another embodiment of the present invention.

As shown in FIG. 4(a), when the corner angle (ω0) of the LMR resist 13 becomes considerably small, first, the shadow portion 30 required to form a predetermined fine pattern is In order to set, A f as a mask material
WA 31 is deposited from an oblique direction at an angle θ with respect to the vertical direction by electron beam evaporation.

Next, as shown in FIG. 4(b), in order to cover the partition on the opposite side to the side on which the fine pattern is to be formed, the ^l film 32 as a mask material is vertically deposited by electron beam evaporation. Vapor deposition is performed from an oblique direction at an angle θ with respect to This vapor deposition still produces shadow areas (gaps) 33.

Next, as shown in FIG. 4(c), in order to cover this shadow portion (gap) 33, an Affi film 34 is deposited from an oblique direction at an angle θ7 with respect to the vertical direction by electron beam evaporation.

By configuring in this way, it is possible to completely cover the predetermined fine pattern except for the shadow portion required to form it.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, the present invention provides the following effects.

Even if a shadow part appears in a part other than the predetermined part where a fine pattern is to be formed, the part can be completely covered with the mask material, so that a desired fine pattern with high precision can be formed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a fine pattern forming process showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of a conventional fine pattern forming process, and FIG. 3 is a fine pattern forming process showing another embodiment of the present invention. FIG. 4 is a cross-sectional view of a process for forming a fine pattern showing still another embodiment of the present invention. 11...Base, 12...0DUR resist, 13...
...LMR resist, 14.19.24...slit, 15.18.20.22.3132, 34...Aj
! Film (mask material), 16.21.23.30...Shadow part, 17...Other shadow part, 33...Shadow part (gap).

Claims (1)

[Claims] A method for forming a fine slit-like pattern in the manufacture of a semiconductor device, comprising: (a) forming a layer of material on which a fine slit-like pattern is to be formed on a substrate; (b) the material; forming a resist layer on the layer; and (c
) forming a reverse tapered slit in the resist layer to selectively expose the material layer; and (d) removing projected shadow portions by setting at multiple angles tilted from perpendicular to the substrate. (e) forming a fine pattern on the material layer by dry etching using the plurality of mask materials as a mask; How to form fine patterns.