JPH05190441A - Formation method of resist pattern - Google Patents

Abstract

PURPOSE:To form a resist pattern wherein its retreat during an etching opera tion of a resist silylating layer is restrained and its size conversion difference is small by a method wherein an oxide film is formed on the surface of the resist silylating layer. CONSTITUTION:A film to be worked or a substrate 1 is first coated with a resist 2 for silylating use; an exposure operation is performed by using a chromium mask having a prescribed shape. Then, this assembly is heated in a hexamethyldisilazane atmosphere; a resist silylating layer 4 is formed. Then, the prescribed amount of a film thickness is removed by a dry etching operation; after that, the shape of the resist silylating layer 4 is oxidized; and an oxide film 5 containing a silicon organic substance is formed. Then, the resist 2 for silylating use which has not been reacted is dry-etched; a resist pattern is formed. Thereby, it is possible to obtain the resist pattern which can enhance the oxygen plasma-resistant property of the resist silylating layer and whose difference from a desired size is small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a resist pattern using a resist silylation process.

[0002]

2. Description of the Related Art FIG. 2 shows a resist pattern forming process using a conventional resist silylation process. First, a film thickness of 1500 is formed on the film to be processed or the substrate 1 by spin coating.
The silylation resist 2 is applied at 0 to 30000Å (FIG. 2A), and exposure is performed using a chromium (Cr) mask having a predetermined shape (FIG. 2B).

Next, hexamethyldisilazane ((C
_{H 3) 3 Si-NH-} Si (CH 3) 3) 150~ atmosphere
The exposed area is silylated by heating at 200 ° C. for 3 to 4 minutes to form a resist silylated layer 4 (FIG. 2C).
After that, dry etching is performed using O ₂ as an etching gas to form a resist pattern (FIG. 2D).
(E)).

As indicated above, the resist silylated layer 4
When resist etching is performed without improving the resistance to oxygen plasma, since the etching rate is higher than the oxidation rate of the resist silylated layer 4, the resist silylated layer 4 that is a mask for resist etching recedes during resist etching. Becomes bigger. Regarding the retreat of the mask,
In the inventors' experiment, a recession of as much as 7% was observed in the depth direction. If a large amount of recession occurs, the influence of the recession is currently suppressed by making the resist silylated layer 4 thicker than a predetermined mask size, for example, by increasing the exposure amount.

[0005]

When the process shown in FIG. 2 is used, the resist silylated layer 4 is formed during resist etching.
Are laterally etched to form a resist pattern having a large difference in size conversion. Further, when the resist silylated layer 4 is made thicker in advance as described above, the space portion becomes smaller as the pattern size becomes smaller, so that it may be less than the resolution limit of the exposure apparatus. Further, the resist silylated layer 4 becomes deep not only in the horizontal direction but also in the vertical direction, so that it becomes difficult to remove the resist after etching.

An object of the present invention is to provide a means for preventing the resist silylated layer from receding during etching by forming an oxide film on the surface of the resist silylated layer.

[0007]

A resist pattern forming method of the present invention is a resist pattern forming method using a resist silylation process, in which a silylating resist is applied onto a film to be processed or a substrate to form a predetermined pattern. A step of silylating the exposed area after exposure, a step of oxidizing the resist silylation layer surface after performing a predetermined amount of etching using the resist silylation layer formed in the above step as a mask, and the above step Then, the unreacted silylation resist is removed by dry etching to form a resist pattern.

[0008]

By using the above steps, it is possible to suppress the receding of the resist silylated layer during etching, and to form a resist pattern with a small dimensional conversion difference.

[0009]

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

FIG. 1 is a process diagram of forming a resist pattern according to an embodiment of the present invention.

First, a silylation resist 2 having a film thickness of about 15,000 to 30,000 Å is applied onto a film to be processed or a substrate 1 by a spin coating method (FIG. 1A), and a chromium (Cr) mask having a predetermined shape is applied. Exposure is carried out (Fig. 1
(B)).

Next, 1 in a hexamethyldisilazane atmosphere
The exposed area is silylated by heating at 50 to 200 ° C. for 3 to 4 minutes to form a resist silylated layer 4 (FIG. 1).
(C)).

Next, the unreacted silylating resist 2 is changed to O ₂
25% to 50% of the film thickness was removed by dry etching using Al as an etching gas (FIG. 1D).
After that, the surface of the resist silylated layer 4 is oxidized under the following conditions. For example, a barrel type ashing device is used, and temperature 2
About 00 ° C, flow rate 300sccm, pressure 400mTorr
By flowing O ₂ gas at r and oxidizing for about 10 minutes,
An oxide film 5 containing a silicon organic substance is formed on the surface of the resist silylated layer 4 (FIG. 1E).

Next, the unreacted silylation resist 2 is replaced with O.
Dry etching is performed using ₂ gases as an etching gas to form a resist pattern (FIG. 1F).
After that, the film to be processed or the substrate 1 is etched without removing the oxide film 5.

[0015]

As described in detail above, by using the present invention, the oxygen plasma resistance of the resist silylated layer is improved, and a resist pattern having a smaller difference from a desired dimension than in the past can be obtained.

[Brief description of drawings]

FIG. 1 is a process drawing of a resist pattern forming process according to an embodiment of the present invention.

FIG. 2 is a process diagram of a conventional resist pattern forming process.

[Explanation of symbols]

 1 Processed Film or Substrate 2 Silylation Resist 3 Chromium Mask 4 Resist Silylation Layer 5 Oxide Film

Claims (1)

[Claims] 1. A method of forming a resist pattern using a resist silylation process, which comprises applying a silylation resist on a film to be processed or a substrate, exposing the exposed film with a predetermined pattern, and then silylating the exposed region, A step of oxidizing the surface of the resist silylation layer after performing a predetermined amount of etching using the resist silylation layer formed in the step as a mask, and after the step, dry etching the unreacted silylation resist. A step of removing and forming a resist pattern.