JPH01195450A - Photomask pattern producing method - Google Patents

Abstract

PURPOSE:To form a precise resist pattern having a high degree of pattern faithfulness by inserting a dummy pattern among photomask patterns where the exposure intensity is high. CONSTITUTION:Black colored rectangular areas (dummy patterns) 4 are inserted among conventional rectangular patterns where the exposure intensity is high 3. The black patterns have a width of about 0.1-0.2mum which is selected in such a way that the width can become narrower than the wavelength of the exposure light source of an exposure device and, at the same time, the patterns are not transferred to the resist. The exposure quantity of the part 3 of the resist pattern formed of the photomask pattern containing the dummy patterns 4 is reduced and uniformized with the other area. Therefore, a resist pattern which is excellent in the degree of pattern faithfulness is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a fine photoresist pattern faithfully to a mask pattern. In particular, the objective is to faithfully form a submicron photoresist pattern of 1.0 μm or less.

2. Description of the Related Art An example of a pattern of a conventional photomask is shown in FIG. Width O
, S μm and a length of 1.6 μm are arranged at a pitch of 1.0 μm in the X direction and 2.0 μm in the Y direction. A Cr film is formed on the photomask in this rectangular portion to block exposure light from the photolithography apparatus. Using this photomask, 1o:1 or 6
FIG. 4 shows an example of forming a positive resist pattern using a step-and-relief type exposure device with a :1 reduction. The rectangular tip portion 1 is rounded into a semicircular shape, and the side portion 2 is concave.
It is not possible to form a resist pattern that is faithful to the photomask pattern.

Problems to be Solved by the Invention As described above, in the conventional example, it was not possible to form a faithful resist pattern. The cause of this is 3 in Figure 4.
Because the intensity of the exposure light in the area shown in is stronger than in other areas, the corners and sides of the rectangular pattern are irradiated with strong light, resulting in overexposure, resulting in curling and dents. This is to do so.

Means for Solving the Problems Accordingly, in the present invention, a dummy pattern so fine that the pattern is not transferred to the resist is inserted into the portion 3 where the exposure intensity is high, thereby reducing the exposure intensity of the portion 3.

Effect As described above, the present invention makes it possible to obtain a more uniform exposure amount over the entire area where there is no photomask pattern.
A resist pattern faithful to the photomask pattern can be formed.

Embodiment FIG. 1 shows an embodiment of the present invention. Rectangular area filled in black between conventional rectangular patterns (dummy pattern) 4
is inserted into the area 3 where the exposure intensity is high. In this case, about 0
．． Insert a pattern with a width of 1 to 0.2 μm. The width of this dummy pattern is determined by the exposure light source wavelength of the exposure device (for example, g-line:
4ssnm, i-line: 366nm) and is selected so that the pattern is not transferred to the resist.

FIG. 2 shows a resist pattern formed using the photomask pattern containing the dummy pattern shown in FIG. Since the exposure amount of portion 3 is reduced and made uniform with that of other regions, a resist pattern with excellent pattern fidelity is formed.

Effects of the Invention According to the present invention, a fine resist pattern with high pattern fidelity can be easily formed by simply inserting a dummy pattern into a photomask pattern.

In particular, in the formation of submicron resist patterns of 1.0 μm or less, the limit performance of the exposure equipment is used, so in order to stably obtain pattern openings, exposure must be performed with a bit of bover exposure, as shown in Figure 4. However, by using the present invention, the exposure amount can be made uniform by inserting a dummy pattern into a desired part of the mask pattern. A pattern is obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a photomask pattern having a dummy pattern according to the method of the present invention, FIG. 2 is a plan view showing a resist pattern exposed using the above pattern, and FIG.
This figure is a plan view showing a conventional photomask pattern, and FIG. 4 is a plan view showing a resist pattern exposed using the pattern. 3... Portion with high exposure intensity, 4... Dummy pattern. Name of agent: Patent attorney Toshio Nakao and 1 other person 4-
-One Tammy Nog Turn Fig. 1 Ifi example Fig. 2 Ifi machine Fig. 3 Hi Fig. 4/)t4rL

Claims (1)

[Claims] A method for forming a photomask pattern in which a dummy pattern having a wavelength narrower than the exposure wavelength of a photolithography apparatus and less than the pattern resolution of the photolithography apparatus is installed close to a pattern to which a desired resist pattern is to be transferred.