JPS607128A - Formation of resist pattern - Google Patents

Abstract

PURPOSE:To form the titled pattern corrected in dimensions by a method wherein a pattern is depicted in a resist film on a substrate by means of a raster type electron beam exposure device, and then a pair of patterns for dimensional correction and detection are image-drawn in point symmetry with respect to the former pattern and are developed. CONSTITUTION:A positive resist film 1 is formed on a blank mask, and the pattern about 10mum square is image-drawn thereon by means of said exposure device. The patterns 21 and 22 for dimensional correction and detection having two shapes are image-drawn in the region of the resist film 1 other than this pattern region under the same condition. Next, patterns 21' and 22' for dimensional correction at positions shifted from those for the image-drawing of the patterns 21 and 22 by an amount less than an integer multiple of the address unit are image- drawn. After the resist film is developed, the development is stopped at the time of the contact of corners of resist patterns 31, 31' and 32, 32' for detection in two pairs formed by the development of the dimensional correction pattern.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for forming a resist pattern, and in particular, the present invention relates to a method for forming a resist pattern, and in particular, the resist pattern is exposed using a rask-type electron beam exposure device, and developed to correct dimensions of an integer multiple or less of an address unit. The present invention relates to a method of forming a resist pattern.

[Technical background of the invention and its problems]

In a rask type electron beam exposure device, it is 0.25 μm.

An address unit with variable steps such as 0.5 μm or 1.0 μm is used. For example 0.5μ
When an address unit of m is adopted, the soturn data is expressed in units of 0.5 μm, so the raster method drawing based on it is 0.5 μm as shown in the model diagram of the first ν1.
This is done with a beam diameter of .mu.m and an increment of 0.5 .mu.m, and the drawn Noreen dimensions are obtained as integral multiples of 0.5 .mu.m.

However, since one mask had a line width of 1.8 μm and another had a line width of 243 μm, the desired mother turn dimension is not necessarily an integer multiple of the address unit. Not necessarily. In such a case, it is necessary to perform dimension correction of an integral multiple or less of the address unit.

By the way, conventionally, as a method of forming a resist pattern whose dimensions have been corrected by an integral multiple of the address unit or less, the pattern dimensions are controlled by changing the development time of a resist film exposed by an electron beam exposure device. It is.

However, with this method, it is difficult to detect how much the width of the resist pattern has been corrected, and it is not possible to form a resist pattern whose size has been corrected with good reproducibility.

For this reason, the present inventors have already developed an integer number of address units by adjusting the parameters of the electron lens barrel system such as the beam diameter and beam current to change the dose amount during exposure using a raster type electron beam exposure system. We have proposed a method for forming a resist pattern whose dimensions have been corrected by less than double (Japanese Patent Application No. 1369/1982). According to this method, when the drawing pattern is constant, it is possible to realize dimension correction with good reproducibility. However, with this method, it is necessary to slightly shift the process conditions for different types of patterns, making the operation complicated. Moreover, even if the process conditions are constant, variations in the parameters of the electron optical barrel system, variations in Rennost characteristics between lots, etc. have a negative effect on the reproducibility in realizing dimensional correction.

[Purpose of the invention]

The present invention aims to provide a method for easily and reproducibly forming a resist pattern whose dimensions have been corrected by an integral multiple or less of the address unit.

[Overview of the invention]

The present invention uses a raster-type electron beam exposure device to draw a pattern on a resist film on a substrate by turning the electron beam on and off with address units at equal intervals, and then develops the resist film so that it is not more than an integer multiple of the address unit. When forming a resist pattern whose dimensions have been corrected, the resist film is written with a thousand turns using an electron beam, and the corners of the resist film area other than the lean writing area are aligned in the X and Y directions. a step of point-symmetrically drawing a pair of dimensional correction detection no.f turns separated by a distance equal to or less than an integral multiple of the address unit; The gist of this method is to form the above-mentioned resist pattern by including a step of developing so that the end point is the point of contact between the corners of the resist pattern.

5- [Embodiments of the invention] The present invention will be explained in detail below.

First, a blank resist such as polymethyl methacrylate (PMMA) was spin-coated on a blank mask, dried, and subjected to a glybake treatment to form a positive resist film 1 having a thickness of 0.5 μm.

Next, on the resist film 1, using a raster type electron beam exposure device, an arless unit (Arres unit) of 0.5 μm and an accelerating voltage of 20
1 on the data under the conditions of keV and dose amount 9.2μch2
A 0 μm square pattern (not shown) was drawn. Next, under the same conditions, the area of the resist film 1 other than the main turn area is 4 μm x 16 μm in data, and the coordinates of a specific corner are (x1 + y1) + (X2 + y;) 2
Dimensional correction detection putter 721.22 having a rectangular shape
was drawn.

Continuing, the drawing start position of the pattern 21+22 is shifted by an amount less than an integral multiple of the address unit, and the coordinates corresponding to the corner part are shown in the following formula (XIZ 7+')
+ (x2'+yz') on the data 4. c+mX16μ
A dimension correction detection pattern-6=21', 22' having a rectangular shape of m was drawn (as shown in FIG. 2).

xl'=x1-ΔL-(aXi) y weight'=y1+ΔL-1-(bXg) dimensional correction value, for example 0.6 μm, a-X direction pattern width (4 μm), b=y direction/turn length 16 μm), S=niscale factor (for example 1.2).

By the electron beam exposure described above, as shown in FIG.
Two pairs of point-symmetric rectangular dimension correction detection patterns 21.21' and 22.22' separated by a distance of ) were drawn.

Next, after developing the resist film after electron beam drawing with methyl isobutyl ketone (developer), a flat turn 21 r for dimension correction detection is formed as shown in FIG.
Two pairs of detection resist/mother turns 31+31' formed by developing 21'+22+22'
and corner portion C1 of 3z+, 9j.

When C1' and C2+C2' came into contact, development was stopped and a resist pattern (not shown) was formed in the 79 turn formation region of the blank mask.

When the dimensions of the resist pattern formed in this example were measured, it was found that the following equation (12, 8
It was μm square.

10×S+ΔL=10Xl, 2X0.6=12.8(
.mu.m) As is clear from the measurement results, it is possible to form a resist pattern whose dimensions are corrected by an integral multiple or less of the address unit (here, 0.6 .mu.m). In addition, in the development process, as shown in FIG. 3(b), the main turn 2I + 21Z 22 * 22' for size correction detection is used.
Two pairs of detection resist films and turns 41 were formed by the development of the film.

41' and '2+42' corner parts C1, C,' and C
When development was stopped with 8+C2' not in contact,
A resist pattern having a dimension p0.15 μm short of the target dimension correction value was formed on the blank mask.

Therefore, according to the present invention, a pair of dimension correction detection patterns are formed in a region different from the pattern formation region of the resist film and are spaced apart by a distance corresponding to a dimension correction value that is an integral multiple of the address unit or less. By determining the end of development in the development process at the time when the corner portions of the resist patterns for detection of these patterns come into contact with each other, a resist/matrix whose dimensions have been corrected by an integer multiple or less of the address unit in the 4-turn formation area is obtained. Turns can be easily formed on a blank mask with good reproducibility.

Note that although a blank mask was used as the substrate in the above embodiment, the substrate is not limited to this, and for example, a wafer may be used.

In the above example, PMMA was used as the resist film, but
The present invention is not limited thereto, and other positive resists or negative resists can be used as well.

9- In the above embodiment, the f-turn 21+2 for dimension correction detection is first
2, and set the drawing start position to address pattern 21'
+22' is drawn, but the deflection start position may be shifted by an amount equal to or less than an integral multiple of the unit.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a method for easily and reproducibly forming a resist pattern whose dimensions have been corrected by an integer multiple or less of the address unit.

[Brief explanation of the drawing]

Figure 1 shows a 0.5 μm exposure using a mask-type electron beam exposure system.
FIG. 2 is a plan view showing a dimension correction detection pattern drawn on a resist film in an embodiment of the present invention; FIG.
Figures (a) and (b) are plan views showing detection resist patterns when the resist film of the same example is developed. 1... Positive resist film, 21.2. ．． 21'...
Pattern, 31 + 32 + JIZ 32'+41
+10- 42 r 41'142'...Resist pattern. -11- Fig. 1 Fig. 2 C) haiku ^ sun, 0

Claims (1)

[Claims] After drawing a pattern on the resist film on the substrate using a Rusk-type electron beam scanning device by turning the electron beam on and off with address units at equal intervals, a development process is performed to form the address units. When forming a resist pattern whose dimensions have been corrected by an integral multiple of A process of point-symmetrically drawing a pair of dimensional correction detection/mother turns spaced apart by a distance equal to or less than an integral multiple of the address unit, and a step of drawing the resist film with a developer to form corners of the pair of dimensional correction detection patterns. A method for forming a resist/mother turn, comprising the step of developing so that the point of contact is the end point. (2) A pair of dimension correction detection resistors according to claim 1, characterized in that the turns thereof have a rectangular shape.
How to form a 1+ turn. (3) Claim 1, characterized in that a plurality of pairs of dimension correction detection patterns are drawn on the resist film.
The method for forming a resist pattern according to item 1 or 2.