JPS5892223A - Resist pattern formation - Google Patents

Abstract

PURPOSE:To eliminate the need for a mask having difficult manufacture under ion beam exposure by a method wherein the second resist is applied after the first resist is applied on a predetermined substrate and ion beam exposure is performed after forming a predetermined figure on the second resist by exposure and development processes and then the first resist is developed. CONSTITUTION:AZ2400 resist 7 is applied as the first resist on an Si substrate 1 and after prebaking, PBS resist 8 is applied at the second resist for prebaking. A predetermined figure is exposed with the aid of an electron beam exposure device. Development is done by special developer for PBS. The AZ2400 resist has low sensitivity to electron beams, thus the AZ2400 resist is not exposed to open a window 9 in the PBS resist 8. Next, ion beam exposure is done with the aid of proton ion 6. At that time, the PBS resist 8 acts as a mask for ion beams and only the AZ2400 resist 7 is exposed. Finally, development for AZ2401 is done to form a resist pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a resist pattern on a predetermined substrate using ion beam exposure.

The technique of applying pattern -kM light onto a resist using an ion beam is not affected by diffraction or proximity effects, and is therefore often used to form ultra-fine patterns. FIG. 1 shows a conventional example of ion beam exposure using a mask. A mask consisting of an ion absorbing material 4 and an ion-permeable thin film 5 is placed on a substrate 1 coated with a resist 2 via a spacer 3, and exposure is performed using an ion beam 6. In this case, the problems include the difficulty in manufacturing the mask, the presence of scattering and distortion due to the mask, and the difficulty in overlapping the mask and substrate.

In the present invention, after coating a first resist on a predetermined substrate, a second resist is applied.
A method for forming a resist pattern, comprising applying a resist on the cylinder 1, forming a predetermined pattern on the second resist through exposure and development steps, performing ion beam exposure, and then developing the resist on the cylinder 1. According to the present invention, the above-mentioned problems are solved, and it is not necessary to manufacture a mask, and moreover, overlapping can be easily performed.

The present invention will be described in detail below based on Examples.

As shown in FIG. 2 (&), a Muz240o resist 7 is applied to a thickness of 0.6 μm as the first resist on the Si substrate 1, and after prebaking at 90° C. for 10 minutes, a second resist is applied.
As a resist, PBS resist 8 is applied to a thickness of 1 μm, and prebaked at 160° C. for 30 minutes.

Using an electron beam exposure device, marks in the original figure are detected and superimposed, and a predetermined figure is exposed. The exposure amount is 1
×1O-6C/cd. Development was performed for 1 minute using a PBS exclusive developer. The Mu Z 2400 resist is not exposed due to its low sensitivity to the electron beam. Through the above steps, a window 9 is opened in the PBS resist 8 as shown in FIG. 2(b).
Proton ion 6 at exposure amount I x 10-60/614
Ion beam exposure is performed as shown in FIG. 2(C). At this acceleration voltage, the penetration depth of protons into the resist is about 0.7 μm, so the PBS resist 8 acts as a mask for the ion beam, and only the mu22400 resist exposed inside the window 9 is exposed.

Finally, as shown in FIG. 2(d), a resist pattern is formed by developing using a developer of 1 part Muz2401 developer and 4 parts water.

Note that a resist pattern can be formed even if a PCM layer is used as the second resist and other conditions are set to be the same as those shown in the above embodiments. According to the method, a fine pattern can be formed on resist AZ2400, which has excellent dry etching resistance. In addition, since ion beam exposure performs batch transfer, it takes a very short time.However, since the drawing time required for electron beam exposure depends on the light-sensitive PBS resist or PGM resist, pattern formation becomes faster.

Furthermore, the resist pattern forming method according to the present invention can be applied to resists other than those described in this embodiment and exposure methods other than electron beam exposure.

As described above in detail, according to the present invention, it is possible to eliminate the need for a mask that is difficult to manufacture in ion beam exposure, and moreover, it is possible to easily perform overlapping.

[Brief explanation of the drawing]

FIG. 3 is a cross-sectional view illustrating on-beam exposure. 1...°...Substrate, 6...Ion beam, 7
. . . first resist layer, 8 . . . second resist layer, 9 . . . window provided in second resist layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] After coating a first resist on a predetermined substrate, a second resist is coated on the first resist, and then exposed and developed to form a predetermined pattern on the second resist, and then ion A method for forming a resist pattern, comprising performing beam exposure and then developing the first resist.