JPH04137616A - Device and method for applying resist film - Google Patents

Abstract

PURPOSE:To form a resist film of a constant thickness on a mask blank by providing a body section having a rotating table on which a sample is put with its center at the rotation axis, and a nozzle section for dripping a resist solution on to the center of the sample. CONSTITUTION:At first, a mask blank 16 is put on the rotating table 15 of a body section 11, and a resist scattering preventing cover 19 is closed. After that, a resist solution is dripped on to the center of the mask blank 16 from a resist solution dripping nozzle 20. On this occasion, the resist dripping nozzle 20 is so controlled that the resist solution may be dripped on the center of the mask blank 16 without fail. Next, a driver section 12 drives the rotating table 15 in order to rotate it at a constant low speed. And when the resist solution is dripped to a degree that it covers the surface of the mask blank 16, the rotating speed of the rotating table 15 is switched over to high-speed rotation. After that, the rotation is continued for a given time, and when the resist film is formed uniformly on the mask blank 16, the rotating table 15 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention particularly relates to improvements in a resist film coating apparatus and method for forming a resist film on a mask blank in a mask making process.

(Prior art) Conventionally, when creating a mask for semiconductor device manufacturing,
Generally, a mask blank having a resist film formed on its surface is used. That is, by irradiating this mask blank with an electron beam from an electron beam exposure device and developing it, a mask having a predetermined pattern is formed.

Here, the following method is mainly used to form a resist (for example, polymethyl methacrylate) film sensitive to electron beams on the surface of a mask blank.

First, a mask blank is placed on a rotating table of a resist film coating device. After this, the resist solution is randomly or linearly dropped onto the mask blank.

Further, the rotary table is rotated at a certain constant speed (for example, 101,000 rpm) to form a resist film of about 5,000 resists on the mask blank.

However, according to the above method, the resist liquid is dropped randomly or linearly onto the mask blank. Further, a resist film is formed by rotating the turntable at a constant speed. For this reason, on the mask blank,
A resist having a constant thickness is not necessarily formed, and the thickness often becomes uneven, which has the drawback of adversely affecting the formed pattern.

Specifically, as shown in Figure 6, the thickness of the resist film formed on the mask blank may be thinner at the periphery (
(see figure (a)) or in the peripheral area (see figure (b)). That is, there were variations in the thickness of the resist film over the entire surface of the mask blank.

Incidentally, as shown in FIG. 7, the variation in the film thickness of the resist film causes variation in the pattern dimensions on the mask blank formed through the post-process. In other words, this variation in pattern dimensions is noticeable in the peripheral area of the mask blank, and is also a major cause of variation in the thickness of the resist film.

On the other hand, in resist coating equipment, the nozzle for dropping the resist solution was also placed at an arbitrary position on the rotary table, so when dropping the resist solution onto the mask blank, the dropping position was uneven. . Furthermore, since the rotary table was rotated in such a state, this was a cause of variations in the thickness of the resist film.

(Problem to be Solved by the Invention) In this way, conventionally, a resist solution was dripped randomly or linearly onto a mask blank, and a resist film was formed by rotating a rotary table at a constant speed. . Further, the nozzle was also placed at an arbitrary position on the rotating table. For this reason, a resist film of a constant thickness is not necessarily formed on the mask blank, and the film thickness becomes uneven.
There was a drawback in that it had a negative effect on pattern dimensions.

The present invention has been made to solve the above drawbacks,
It is an object of the present invention to provide a resist film coating device and method capable of forming a resist film of a constant thickness on a mask blank.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the resist film coating device of the present invention is rotatable and coats the sample so that the center of the sample is aligned with the axis of rotation. The sample includes a main body portion having a rotary table on which the sample is placed, a drive portion for driving the rotary table, and a nozzle portion for dropping resist liquid onto the center of the sample.

Further, a control section capable of controlling the rotational speed of the rotary table is provided.

In the resist film coating method of the present invention, first, a resist solution is dropped onto the center of a sample, and the sample is rotated at a low speed about the center of the sample.

After a certain period of time has elapsed, the rotation speed of the sample is switched from low speed to high speed, and a resist film is uniformly applied onto the sample.

(Function) According to the above configuration, the resist liquid is dropped onto the center of the sample by the nozzle part, and the rotary table is driven by the drive part. Further, the rotation speed of the rotary table is controlled by the control section. Therefore, a resist film with a constant thickness is formed on the surface of the mask blank, and variations in pattern dimensions on the patterned mask blank can be improved or almost eliminated.

Further, according to the above method, a resist solution is dropped onto the center of the sample, and a resist film is formed on the mask blank by controlling the rotation speed of the rotary table I7. Therefore, a uniform resist film is formed on the surface of the mask blank, and variations in pattern dimensions on the patterned mask blank are improved.

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

FIG. 1 is a block diagram showing the basic configuration of a resist film coating apparatus of the present invention.

This resist film coating apparatus includes a main body part 11 having a rotary table on which a mask blank (sample) is placed, a drive part 12 that drives the rotary table, and a nozzle part 13 that drips resist liquid onto the mask blank. It is made up of. Moreover, these main body part 11, drive part 12, and nozzle part 1
3 is controlled by the control section 14.

FIG. 2 specifically shows the main body $11. In FIG. 2, 15 is a rotary table, 16 is a mask blank, 17 is a mask blank fixing member, 18 is an exterior material of the rotary table holder, 19 is a resist scattering prevention cover, and 20 is a resist liquid pouring nozzle.

A mask blank 16 is placed on the rotary table 15. The upper mask blank 6 is fixed by mask blank fixing members 17 on all sides thereof. Note that the rotation axis of the rotating table 15 and the center of the mask blank 16 coincide with each other. The resist liquid pouring nozzle 20 is arranged such that its spout is located at the center of the mask blank 16, that is, directly above the rotation center of the rotary table 15. Further, the rotary table holder of the rotary table 15 is disposed on the exterior material 18 and covered with a resist scattering prevention cover 19.

Next, the basic operation of the resist film coating apparatus of the present invention will be explained in detail with reference to the block diagram shown in FIG. 1, the external view shown in FIG. 2, and the flowchart shown in FIG. 3. .

First, the mask blank 16 is placed on the rotating table 15 of the main body 11.
Place. Note that the mask blank 16 has a glass layer 1
A chromium layer 16b is formed on the chromium layer 6a. Additionally, the resist scattering prevention cover 19 is closed. Thereafter, the resist solution is dripped onto the center of the mask blank 16 from the resist solution pouring nozzle 20. Here, the resist liquid pouring nozzle 20 always supplies the resist liquid to the mask blank 1.
6 (step 5TI). Next, the turntable 15 rotates at a constant and low speed (
The rotating table 15 is driven by the driving unit 12 so that the rotation speed is around 300 rpm (step 5T2). Next, when the resist solution reaches a level that covers the surface of the mask blank 16 due to this rotation, the rotation speed of the rotary table 15 is switched from low speed rotation to high speed rotation (approximately 1000 rprn) (step 5T3). Thereafter, the rotation is continued for a certain period of time, and when a resist film is uniformly formed on the mask blank 16, the rotating table 15 is stopped (step 5T4).
).

Using the resist film coating device and method as described above,
When a resist film was formed on the surface of the mask blank 16, the results shown in FIG. 4 were obtained.

In other words, as can be seen from the figure, there is almost no variation in the thickness of the resist film between the center and the periphery of the mask blank 16, and between the periphery and the band. That is,
The resist film can be uniformly applied onto the mask blank 16. Therefore, as shown in FIG. 5, it is possible to improve or almost eliminate variations in pattern dimensions on the mask blank 16 that are patterned through post-processing. There is no doubt that improving or almost eliminating variations in pattern dimensions will be highly effective in the future in the production of masks for semiconductor device manufacturing, where patterns will become increasingly finer.

Incidentally, in the above embodiment, the case where a resist film is formed on the mask blank 16 has been described in detail, but it goes without saying that the present invention can also be applied to, for example, a case where a resist film is formed on a wafer.

[Effects of the Invention] As described above, the resist film coating apparatus and method of the present invention provides the following effects.

It is possible to form a resist film with a constant thickness on the surface of the mask blank. Therefore, variations in pattern dimensions on the patterned mask blank 16 can also be improved or almost eliminated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of a resist film coating apparatus according to an embodiment of the present invention, FIG. 2 is a diagram specifically showing the main body portion 11 of FIG. 1, and FIG. FIG. 4 is a flowchart showing the basic operation of the resist film coating device; FIG. 4 is a diagram showing film thickness variation within the mask blank surface when a resist film is formed using the resist film coating device and method of the present invention; FIG. A diagram showing variations in pattern dimensions within the plane of a mask blank when a resist film is formed using the resist film coating apparatus and method of the present invention, FIG. 6 is a diagram showing variations in film thickness within the plane of a conventional mask blank, FIG. 7 is a diagram showing variations in pattern dimensions within the plane of a conventional mask blank. DESCRIPTION OF SYMBOLS 11... Main body part, 12... Drive part, 13... Nozzle part, 14... Control part, 15... Turntable, 16...
Mask blank, 17... mask blank fixing member,
18...Rotating table support is an external device, 19...Resist scattering prevention cover 20...Resist liquid pouring nozzle. Applicant's representative Patent attorney Takehiko Suzue Figure Figure Figure A Figure Figure Mask equal division number Figure 6 Mask equal division number Mask equal division number Mask equal division - Figure

Claims (3)

[Claims] (1) A main body part that is rotatable and has a turntable on which the sample is placed so that the center of the sample is aligned with the axis of rotation, a drive part that drives the turntable, and a drive part that drives the turntable, and 1. A resist film coating device comprising: a nozzle portion for dropping a resist solution; (2) The resist coating apparatus according to claim 1, further comprising a control section capable of controlling the rotational speed of the rotary table. (3) Dropping a resist solution onto the center of the sample, rotating the sample at a low speed about the center of the sample, and switching the rotation speed of the sample from low speed to high speed after a certain period of time has elapsed; A resist film coating method characterized by uniformly coating a resist film on the sample.