JPH08339985A - Pattern forming method for very fine processing, and very fine processing method using the pattern forming method - Google Patents

Abstract

PURPOSE: To provide a pattern forming method for a very fine processing wherein its processes are simple, and its cost can be reduced, and further, its pattern accuracy is also improved, and to provide a very fine processing method using the pattern forming method. CONSTITUTION: On a substrate 10, a polysilane layer 15 made of polysilane is provided. Then, by the selective exposure of the polysilane layer 15 in atomosphere through the projection of a Deep-UV thereon, exposure portions 15a of the polysilane layer 15 are changed into from polysilane to polysiloxane. Subsequently, by a plasma etching using a HBr gas, unexposure portions 15b of the polysilane layer 15 are removed to leave the exposure portions 15a as patterns. Thus, by etching the substrate 10 using the patterns 15a as masks, its very fine processing is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor elements and devices,
Alternatively, the present invention relates to a method for forming a pattern for fine processing and a fine processing method using this method in the manufacturing process of electronic components and the like.

[0002]

2. Description of the Related Art The following methods are generally well known as a method of finely processing a wiring pattern or the like in the manufacturing process of semiconductor elements and devices. First, a film to be processed and a resist layer are sequentially provided on a substrate such as a semiconductor wafer, and then a resist pattern is formed through exposure and development steps. Next, by etching using this resist pattern as a mask, the pattern is transferred to the film to be processed for processing. However, in such a pattern forming method, in recent years, there has been a limit to fine processing, and therefore, the literature: SPIE, Vol.1086 Advances in Resist
As disclosed in Technology and Processing VI, 1989, pp.220-228, a method referred to as a surface silylation process method has been studied.

According to this method, first, a film to be processed and a resist layer are sequentially provided on a substrate such as a wafer and exposed by various kinds of light and electron beams. Next, the substrate is heat-treated. Next, in the liquid phase or the gas phase, a silylating agent is used to silylate the vicinity of the surface of the exposed or unexposed portion of the resist.
Then, using the silylated portion as a mask, O ₂ -RIE (Reac
tive Ion Etching)
A resist pattern is formed. After that, fine processing is performed by etching the film to be processed using the resist pattern as a mask to obtain a desired pattern.

[0004]

However, even the method of this document has the following problems.

In the above literature, the conditions for forming a resist pattern are polyvinyl (phenol), 2 (4-phenyl-phenyl) -4,6-bis (trichloromethyl).
I-line exposure is performed using a chemically amplified resist composed of -s-triazine and hexamethoxymethylmelamine,
The resist surface is silylated in the gas phase on the unexposed area. Therefore, even if a resist having a thickness of 1.3 μm is used, a low exposure amount of 25 mJ / cm ² can be achieved in an amount of 0.
A pattern having a fine pattern width of 6 μmL / S (Line and Space) has been successfully formed. As described above, the surface silylation process method can pattern only the vicinity of the surface of the resist, so that a pattern having a high aspect ratio (ratio of height and width) can be obtained, which can be said to be suitable for fine processing.

However, on the other hand, the O ₂ − of the resist used is
Since the RIE resistance is not sufficient, the pattern surface is roughened. Further, due to the swelling by the silylating agent, the boundary line between the silylated portion and the portion to be removed by etching recedes toward the removed portion (hereinafter referred to as dimension receding), and the profile after etching deteriorates. I will end up. In addition, the process is complicated by exposure-heating-silylation-etching.

Therefore, it has been desired to provide a method of forming a pattern for microfabrication and a microfabrication method using this method, which has a simple process and improves pattern accuracy.

[0008]

Therefore, the inventors of the present application, by using polysilane as an alternative to the conventional one functioning as a resist, form a patterning method for fine processing as described below. Moreover, the fine processing method using this method was found. Hereinafter, means for performing these methods will be described separately for forming a negative pattern and a positive pattern.

1. Formation of Negative Pattern 1.-1.-1. According to the method for forming a pattern for microfabrication according to claim 1 of this application, the following steps are included.

A polysilane layer made of polysilane is provided on the base. By selectively exposing the polysilane layer in an oxygen-containing atmosphere, the exposed portion of the polysilane layer is changed from polysilane to polysiloxane. The unexposed portion of the polysilane layer is removed by performing plasma etching using an acid gas.

In carrying out the method for forming a pattern for fine processing according to claim 1, the exposure is performed by UV light, Xe-Cl.
It is preferable to perform light exposure using one selected from an excimer laser, a KrF excimer laser, an ArF excimer laser, and an F ₂ laser as an exposure source.

1.-1.-2. Next, according to the fine processing method of the third aspect, which uses the above-described method of forming a pattern for fine processing, the following steps are included.

A polysilane layer made of polysilane is provided on the base. By selectively exposing the polysilane layer in an oxygen-containing atmosphere, the exposed portion of the polysilane layer is changed from polysilane to polysiloxane. The polysilane layer in the unexposed portion is removed by performing plasma etching using an acidic gas, leaving the exposed portion as a pattern. The base is finely processed by etching using this pattern as a mask.

1.-2.-1. According to the method for forming a microfabricated pattern according to claim 5 of the present application, it includes the following steps.

A polysilane layer made of polysilane is provided on the base. The polysilane layer is selectively exposed by an O ₂ ⁺ ion beam to change the exposed portion of the polysilane layer from polysilane to polysiloxane. The unexposed portion of the polysilane layer is removed by performing plasma etching using an acid gas.

1.-2.-2. Next, according to the fine processing method of the sixth aspect, which uses the method for forming a pattern for fine processing described above, the following steps are included.

A polysilane layer made of polysilane is provided on the base. The polysilane layer is selectively exposed by an O ₂ ⁺ ion beam to change the exposed portion of the polysilane layer from polysilane to polysiloxane. The polysilane layer in the unexposed portion is removed by performing plasma etching using an acidic gas, leaving the exposed portion as a pattern. The base is finely processed by etching using this pattern as a mask.

2. Formation of positive pattern 2.-1.-1. According to the method for forming a pattern for fine processing according to claim 7 of the present application, a polysilane layer made of polysilane is provided on a base, and the polysilane layer is Selective exposure is performed using one selected from a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam.

2.-1.-2. Next, according to the microfabrication method of claim 8 which uses the above-described method for forming a pattern for microfabrication, the following steps are included.

A polysilane layer made of polysilane is provided on the base. The polysilane layer is selectively exposed by using one selected from a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam to remove the exposed portion and leave the unexposed portion as a pattern. The pattern is entirely exposed in an oxygen-containing atmosphere. The base is finely processed by etching using the pattern as a mask.

In all the microfabrication pattern forming methods and microfabrication methods of this application, the polysilane layer is preferably provided by plasma polymerization.

[0022]

According to the method for forming a pattern for microfabrication according to claim 1 of the present application, a polysilane layer is provided on the underlayer, and the polysilane layer is selectively exposed in an oxygen-containing atmosphere to perform exposure. The part is changed from polysilane to polysiloxane. When the polysilane layer is selectively exposed in the oxygen-containing atmosphere as described above, the exposed portion is changed to polysiloxane, which is known to have good etching resistance (O ₂ -RIE resistance). It is considered that this is because oxygen is introduced into the Si-Si bond of the polysilane chain to form the Si-O-Si bond as shown in the following formula.

[0023]

Embedded image

Next, the unexposed portion of the polysilane layer is removed by etching using an acid gas. For example, when plasma etching is performed using HBr gas,
As shown in the following formula, it is considered that the polysilane in the unexposed portion is removed because the polysilane chain in the unexposed portion is cut and bonded with HBr.

[0025]

Embedded image

Therefore, a pattern for fine processing can be formed by a simple process of exposure-etching. Further, since the polysiloxane having good etching resistance is left as the pattern, the pattern can be formed with high accuracy, and there is no fear of surface roughness. Furthermore, since a developing solution and a silylating agent are not used, there is no risk of dimensional swelling due to swelling.

Next, according to the fine processing method of the third aspect, the pattern is finely processed by etching using the pattern formed by the above-described fine processing pattern forming method as a mask. In this way, since the pattern formed with very high pattern accuracy without surface roughness or dimensional receding is used as a mask, it is possible to similarly perform fine processing of the base with high accuracy.

Next, according to the method for forming a microfabrication pattern according to claim 5 of the present application, a polysilane layer made of polysilane is provided on the underlayer, and the polysilane layer is formed as
Selective exposure with a ₂ ⁺ ion beam is performed to change the exposed portion from polysilane to polysiloxane, and then the unexposed portion of the polysilane layer is removed by performing plasma etching using an acid gas.

Therefore, also by this method, a pattern for fine processing can be formed by a simple process of exposure-etching. Further, since the polysiloxane having good etching resistance is left as the pattern, the pattern can be formed with high accuracy, and there is no fear of surface roughness. Furthermore, since a developing solution and a silylating agent are not used, there is no risk of dimensional swelling due to swelling.

Further, according to the fine processing method of the sixth aspect, the pattern is finely processed by using the pattern formed by the above-described fine processing pattern forming method as a mask, so that the processing is performed accurately. be able to.

According to the method described above, a negative pattern is formed.

Next, according to the method of forming a pattern for microfabrication according to claim 7 of this application, a positive pattern is obtained by changing the exposure method from the method according to claim 5 described above. That is, a positive pattern is obtained when the exposure is performed with any one of a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam.

Next, according to the fine processing method of the eighth aspect, the pattern is finely processed by etching using the pattern formed by the method for forming a pattern for fine processing as a mask. At this time, if the obtained pattern for microfabrication is entirely exposed in an oxygen-containing atmosphere, polysilane becomes polysiloxane, which has etching resistance, so that the base can be accurately processed.

In the method for forming a finely processed pattern and the finely processed method of this application, all steps can be dry processes. For example, an all dry process can be performed by providing a polysilane layer by plasma polymerization using methylsilane or the like.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. Each drawing merely schematically shows the size, shape, etc. of each constituent component to the extent that the invention can be understood, and is not limited thereto. Also,
Although specific materials and conditions are used in the following description,
These materials and conditions are only one of the preferred examples, and thus are not limited thereto. In each figure, the same components are designated by the same reference numerals.

<First Example> In the first example, first, a sample is prepared by the following steps, which shows that polysilane is converted into polysiloxane when exposed to light in an oxygen-containing atmosphere. After checking. The process of sample preparation is not shown.

First, methylsilane (M
Layer thickness of 0.2μ by plasma polymerization using eSiH ₃ )
m polysilane layer was provided. The polysilane layer is formed by using a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva Co.) as a device, gas pressure 1.0 Pa, gas flow rate 20 SCCM, RF power density 0.12 W / cm.
^2. Polymerization time was 5 minutes. Next, the entire surface of the formed polysilane layer was irradiated with Deep-UV light by using a Xe-Hg lamp equipped with a CM250 cold mirror, and exposed in the atmosphere. When the structure subjected to the above treatment was analyzed by IR spectrum, absorption by the Si—O bond which was not found in the unexposed part was observed in the exposed part. This shows that polysilane was changed to polysiloxane in the exposed portion.

1A to 1D are explanatory views of a method of forming a pattern for microfabrication according to claim 1 of the present application, and a first embodiment of the microfabrication method according to claim 4. FIG. These will be described in the same embodiment. In FIG. 1, hatching showing a cross section is omitted except for a part. According to the method for forming a pattern for microfabrication according to claim 1 of this application, first, a polysilane layer made of polysilane is provided on a base. In this embodiment, the underlayer 10 is composed of a thermally oxidized wafer 11 and a W layer 13 having a layer thickness of 0.8 μm, which is a film to be microfabricated (processed film) provided on the wafer 11. It has a two-layer structure. Methylsilane (M
Layer thickness of 0.2μ by plasma polymerization using eSiH ₃ )
m polysilane layer 15 was provided ((A) of FIG. 1). The polysilane layer 15 is formed by using a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva) as a device, a gas pressure of 1.0 Pa, a gas flow rate of 20 SCCM, an RF power density of 0.12 W / cm ² , and a polymerization time of 5 minutes. I went under the condition.

Next, the polysilane layer 15 is selectively exposed in an oxygen-containing atmosphere to change the exposed portion of the polysilane layer from polysilane to polysiloxane. In this embodiment, a mask (not shown) is placed on the polysilane layer 15 described above, and an X of CM250 cold mirror is mounted.
Exposed portion 15a is obtained by irradiating deep-UV light using an e-Hg lamp and selectively performing exposure in the atmosphere.
In, the polysilane was changed to polysiloxane.
((B) of FIG. 1). In FIG. 1B, 15b is an unexposed portion.

Next, the polysilane layer of the unexposed portion 15b is removed by performing plasma etching using an acidic gas. In this example, the substrate after the exposure was subjected to plasma etching with HBr gas using a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva). Etching conditions are gas pressure 1.
0 Pa, gas flow rate 20 SCCM, RF power density 0.1
The etching time was ² W / cm ² and the etching time was 5 minutes. In this way, the exposed portion 15a is left and formed as a pattern for fine processing ((C) of FIG. 1). This negative pattern 15a
Was observed with a SEM (Scanning Electoron Microscope), it was possible to resolve the minimum size of 0.5 μm (L / S) of the mask used in this example. Also, there is no surface roughness on the pattern surface,
The profile was also good.

As can be understood from the above results, according to the method for forming a finely patterned pattern according to claim 1 of the present application, the exposed portion 15a is made of polysiloxane having a high etching resistance, so that a high resolution (high (Precision) pattern can be formed without surface roughness. Further, since a developing solution and a silylating agent are not used, the dimensional swelling due to these swelling does not occur, and a pattern with a good profile can be obtained. Further, the pattern can be formed by a simple (short) process of exposure-etching. Furthermore, since it is an all-dry process, a waste liquid treatment facility is unnecessary, and the manufacturing cost can be reduced.

Next, a fine processing method using the above-described fine processing pattern forming method will be described.

In the fine processing method according to the third aspect, the base is finely processed by etching using the pattern formed by the above method as a mask. In this embodiment, the W layer 13 is formed using the negative pattern 15a as a mask.
Is etched using a mixed gas of Cl ₂ and O ₂ .
The apparatus uses a DEM451 parallel plate type dry etcher (trade name; manufactured by Anelva), gas pressure 2.5 Pa, gas flow rate 15 + 15 SCCM, RF power density 0.32 W / c.
Etching was performed under the conditions of m ² and etching time of 6 minutes. Thus, the processed W layer pattern 13a is formed ((D) of FIG. 1). When the processed W layer pattern 13a is observed by SEM, the negative pattern 15a
Similarly to the above, resolution of 0.5 μm (L / S) was possible. In this way, since the pattern for microfabrication formed with extremely high precision is used as a mask, microfabrication having a high resolution can be achieved in the same manner.

Next, as a modified example of the first embodiment, in the formation of the pattern for fine processing performed in the first embodiment,
A pattern was formed by changing the exposure source. In addition, except that the exposure is performed by using the KrF laser as the exposure source, the pattern is formed by the same steps as those in the first embodiment, and thus the detailed description is omitted. The pattern formed by the modification is S
When observed by EM, 0.35 μm (L / S) was resolvable when the exposure amount was 200 mJ / cm ² . Thus, it can be said that pattern formation with higher resolution can be expected by using an exposure source having a short wavelength.

As the exposure source, Xe-Cl excimer laser, ArF excimer laser, F ₂ laser or the like may be used in addition to UV light and KrF excimer laser. Further, polysilane can be removed in the same manner as in the first embodiment as long as it is an acidic gas such as hydrogen halide gas, boron halide gas or halogen gas.

The selective exposure of the polysilane layer may be performed in an oxygen-containing atmosphere, for example, in a mixed gas of oxygen.

<Second Embodiment> FIGS. 2A to 2D show a method for forming a pattern for microfabrication according to claim 1 of the present application and a method for microfabrication according to claim 3. FIG. 7 is a schematic process drawing for explaining the second embodiment. In the second embodiment, the base 100 has a two-layer structure of a Si wafer layer 13 to be microfabricated and a heat-treated resist layer 14 having a thickness of 1.5 μm provided on the wafer layer 13. There is. In FIG. 2, hatching showing a cross section is omitted except for a part.

When fine pattern processing with a high aspect ratio is performed, it is general that the resist has a multilayer structure. This is because the actual device surface has a complicated step, which causes a problem that the exposure conditions cannot be optimized. Therefore, if the resist has a multi-layer structure, the lower layer resist can flatten the surface and absorb the scattering of incident light at the time of exposure, so that the upper layer resist can form a fine pattern. The second embodiment is an example in which the method for forming a pattern for fine processing of this application is used for forming a multilayer resist.

In this embodiment, first, on the base 100,
As in the first embodiment, a polysilane layer 15 having a layer thickness of 0.2 μm was provided by plasma polymerization using methylsilane (MeSiH ₃ ) ((A) of FIG. 2). The conditions for forming the polysilane layer 15 are the same as in the first embodiment.

Next, a mask (not shown) was placed on the polysilane layer 15, and Xe with CM250 cold mirror was mounted.
Deep-UV light was irradiated using a -Hg lamp to selectively perform exposure in the atmosphere ((B) of FIG. 2).

Next, the exposed polysilane layer 15 was subjected to plasma etching with HBr gas using a DEM451 parallel plate type dry etcher (trade name; manufactured by Anelva). The etching conditions are the same as in the first embodiment. In this way, the unexposed portion 15b is removed, and the exposed portion 15a is left and formed as the negative pattern 15a (FIG. 2C). When this pattern 15a was observed by SEM, the minimum dimension of the mask used in the second embodiment, 0.5 μm (L / S), was resolvable. Further, there was no surface roughness and the like, and the edge and profile were also good.
By using this negative pattern 15a as a mask, the resist layer in the portion exposed from the negative pattern 15a is exposed to O
₂ gas etching (O ₂ -RIE) to remove
A resist pattern 14a was obtained ((D) of FIG. 2). At this time, a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva Co.) was used as an apparatus, and a gas pressure was 1.5 Pa,
Gas flow rate 50SCCM, RF power density 0.12W / c
Etching was performed under the conditions of m ² and etching time of 25 minutes. Since the pattern 15a is made of polysiloxane, it has high etching resistance. When the obtained resist pattern 14a is observed by SEM, the negative pattern 15a is formed.
Similar to a, 0.5 μm (L / S) was resolvable.

<Third Embodiment> FIGS. 3A to 3C are schematic process diagrams for explaining an embodiment of a method for forming a pattern for fine processing according to claim 5 of the present application. is there. This embodiment is called a third embodiment. In FIG. 3, hatching showing a cross section is omitted except for a part.

According to the method for forming a pattern for microfabrication according to claim 5 of this application, first, a polysilane layer made of polysilane is provided on a base. In this example,
First, on the underlayer 10, a methylsilane (MeSiH ₃ ) film was formed by plasma polymerization in the same manner as in the first embodiment to a layer thickness of 0.
A 2 μm polysilane layer 15 was provided ((A) of FIG. 3).
The conditions for forming the polysilane layer 15 are the same as in the first embodiment.

Next, the polysilane layer is selectively exposed by an O ₂ ⁺ ion beam to change the exposed portion of the polysilane layer from polysilane to polysiloxane. In this example,
A mask (not shown) is placed on the polysilane layer 15, and O
Selective exposure was performed with a ₂ ⁺ ion beam (FIG. 3 (B)).
The acceleration voltage of the O ₂ ⁺ ion beam was 0.5 kV, and the implantation amount was 10 ²¹ cm ² . As a result, the exposed portion 15a was changed to polysiloxane.

Next, the polysilane layer of the unexposed portion 15b is
It is removed by performing plasma etching using an acid gas. In this embodiment, as in the first embodiment, the DEM
Plasma etching with HBr gas was performed using a 451 parallel plate type dry etcher (trade name; manufactured by Anelva). Etching conditions are: gas pressure 1.0 Pa, gas flow rate 20 SCCM, RF power density 0.12 W / cm ² ,
The etching time was 5 minutes. In this way, the exposed portion remained, and the negative pattern 15a was obtained ((C) of FIG. 3).

When the obtained negative pattern 15a was observed by SEM, the minimum dimension of the stencil mask used in the third example, 1.0 μm (L / S), was resolvable. In addition, the pattern surface was not rough and the profile was good.

As can be understood from the above results, according to the method for forming a pattern for microfabrication according to claim 5 of the present application, since the exposed portion 15a is made of polysiloxane having high etching resistance, a high resolution is obtained. It is possible to form a (high precision) pattern without surface roughness.

<Fourth Embodiment> FIGS. 4A to 4C and FIGS. 5A and 5B are a method for forming a pattern for fine processing according to claim 7 of the present application, and FIG. 9 is a schematic process diagram for explaining an embodiment of the fine processing method according to claim 8. This embodiment is called a fourth embodiment. Note that FIG.
In (A) to (C) of FIG. 5 and (A) and (B) of FIG. 5, the hatching showing the cross section is omitted except for a part.

According to the method for forming a pattern for microfabrication according to claim 7 of this application, first, a polysilane layer made of polysilane is provided on a base. In this example,
Wafer 11 obtained by thermally oxidizing base 10 and wafer 1
A two-layer structure including a W layer 13 having a layer thickness of 0.8 μm, which is a film to be finely processed (film to be processed) provided on the substrate 1. A polysilane layer 15 having a layer thickness of 0.2 μm was provided on the base 10 by plasma polymerization using methylsilane (MeSiH ₃ ) as in the first embodiment ((A) of FIG. 4). The conditions for forming the polysilane layer 15 are the same as in the first embodiment.

Next, the polysilane layer is selectively exposed by using one selected from a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam. In this example, a stencil mask (not shown) was placed on the polysilane layer 15 and exposed to HBr plasma for selective exposure. At this time, a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva Co.) was used as the apparatus, and the gas pressure was 1.
0 Pa, gas flow rate 50 SCCM, RF power density 0.1
Exposure was performed under the conditions of ² W / cm ² and an exposure time of 5 minutes. As a result, the polysilane 15a in the HBr plasma irradiation part (exposed part) was removed, and the positive pattern 15b was obtained ((C) of FIG. 4). The obtained positive pattern 15b is S
When observed by EM, the minimum dimension of the stencil mask used in the fourth example, 1.0 μm (L / S), was resolvable. In addition, the pattern surface was not rough and the profile was good.

As can be understood from the above results, according to the method for forming a pattern for fine processing according to claim 7 of the present application, the method according to claim 6 shown in the third embodiment. A positive pattern can be easily obtained by changing the exposure method. Further, exposure and etching can be performed in substantially the same process. Furthermore, since it is an all-dry process, a waste liquid treatment facility is unnecessary, and the manufacturing cost can be reduced.

Next, a microfabrication method using the above-described method of forming a pattern for microfabrication will be described.

According to the eighth aspect of the fine processing method, the positive pattern 15b formed by the method of the seventh aspect is used as a mask to perform etching processing to finely process the base, and the positive pattern 15b is formed. Since it is made of polysilane, the entire surface is exposed in an oxygen-containing atmosphere in order to impart etching resistance. In this embodiment, the positive pattern 15b was irradiated with a Xe-Hg lamp in the atmosphere ((A) of FIG. 5). In this embodiment, W exposed from the pattern 15b and to be microfabricated is used.
The layer 13 is etched with a mixed gas of Cl ₂ and O ₂ . The device is a DEM451 parallel plate type dry etcher (trade name; manufactured by Anerva Co.) with a gas pressure of 2.5 Pa,
Gas flow rate 15 + 15 SCCM, RF power density 0.32
Etching was performed under the conditions of W / cm ² and etching time of 6 minutes. W layer pattern 1 thus processed
3b is formed ((B) of FIG. 5). When the processed W layer pattern 13b was observed by SEM, it was possible to resolve 1.0 μm (L / S) similarly to the positive pattern 15b. In this way, since the pattern for microfabrication formed with extremely high precision is used as a mask, microfabrication having a high resolution can be achieved in the same manner.

<Fifth Embodiment> FIGS. 6 (A) to 6 (C) and FIGS. 7 (A) and 7 (B) show a method for forming a pattern for fine processing according to claim 7 of the present application, and FIG. 9 is a schematic process diagram for explaining an embodiment of the fine processing method according to claim 8. This embodiment is called a fifth embodiment. This is an example in which the method according to claims 7 and 9 is used for forming a multilayer resist. In the fifth embodiment, the base 100 is S
The i-wafer layer 13 and the heat-treated resist layer 14 provided on the wafer layer 13 and having a layer thickness of 1.5 μm. In addition, in FIGS. 6A to 6C and FIGS. 7A and 7B, hatching showing a cross section is omitted except for a part.

In this embodiment, first, on the base 100,
A polysilane layer 15 having a layer thickness of 0.2 μm was provided by plasma polymerization using methylsilane (MeSiH ₃ ) in the same manner as in the first embodiment ((A) of FIG. 6). The conditions for forming the polysilane layer 15 are the same as in the first embodiment.

Next, a stencil mask (not shown) was placed on the polysilane layer 15 and exposed to HBr plasma for selective exposure. At this time, the apparatus uses a DEM451 parallel plate type dry etcher (trade name; manufactured by Anelva), and the exposure is performed under the conditions of gas pressure 1.0 Pa, gas flow rate 50 SCCM, RF power density 0.12 W / cm ² , and exposure time 5 minutes. went. As a result, the polysilane 15a in the HBr plasma irradiation portion was removed, and the positive pattern 15b was obtained ((C) of FIG. 6). The obtained positive pattern 15b is SE
When observed by M, the minimum dimension of the stencil mask used in the fifth example, 1.0 μm (L / S), was resolvable. In addition, the pattern surface was not rough and the profile was good. Next, the positive pattern 15b is entirely exposed by irradiating a Xe-Hg lamp in the atmosphere to change polysilane into polysiloxane ((A) in FIG. 7). Then, using the positive pattern 15b as a mask, etching with O ₂ gas (O ₂ -RI
By performing E), the exposed portion of the resist layer 14 was removed from the positive pattern 15b to obtain a resist pattern 14b ((B) of FIG. 7). Here, even if the above-mentioned entire surface exposure is not performed, polysilane is combined with oxygen and converted into polysiloxane during O ₂ -RIE. Therefore, the whole surface exposure here may be omitted. When the obtained resist pattern 14b was observed by SEM, it was possible to resolve 1.0 μm (L / S) like the pattern 15b.

Obviously, the invention is not limited to the embodiments described above. For example, although the W layer is used as the metal layer to be finely processed in each of the above-described embodiments, for example, Cu or A that is often used as a wiring metal is used.
It is also applicable to microfabrication of a layer made of l. It can also be applied to the processing of layers made of other metals.

[0068]

As is apparent from the above description, according to the method for forming a pattern for fine processing of this application, the property of polysilane is used, that is, exposure is performed in an atmosphere containing oxygen. Alternatively, when it is exposed to an O ₂ ⁺ ion beam, it changes into polysiloxane having good etching resistance. It is removed in association with acid gas. By utilizing this property, it is possible to form a highly accurate pattern by a simple process of exposure-etching.

Since no developing solution or silylating agent is used, there is no risk of dimensional swelling due to swelling of these.
A pattern with a good profile can be formed. In addition, since it is possible to use an all-dry process, waste liquid treatment equipment is not required, and the cost can be reduced.

Similarly, according to the microfabrication method of the present application, the pattern formed by the microfabrication pattern forming method of the present application is used as a mask to etch the film to be processed which is the base of the pattern. Therefore, the pattern can be formed with high accuracy.

[Brief description of drawings]

1A to 1D are process diagrams of a first embodiment of a method for forming a pattern for fine processing according to claim 1 of the present application and a fine processing method according to claim 3; Is.

2A to 2D are process diagrams of a method for forming a pattern for fine processing according to claim 1 of the present application and a second embodiment of the fine processing method according to claim 3; Is.

3 (A) to (C) are embodiments (third embodiment) of the method for forming a pattern for fine processing according to claim 5 of the present application.
FIG.

4 (A) to (C) are examples of a method for forming a pattern for fine processing according to claim 7 of the present application and an example of the fine processing method according to claim 8 (fourth embodiment). FIG.

5A and 5B are diagrams illustrating a method for forming a pattern for microfabrication according to claim 7 of the present application, which is subsequent to FIG. 4;
FIG. 9 is a process drawing of an example of the fine processing method according to claim 8.

6 (A) to 6 (C) are a method of forming a pattern for fine processing according to claim 7 of the present application and another embodiment of the fine processing method according to claim 8 (fifth embodiment). It is a process drawing of (Example).

7 (A) and (B) is a method for forming a pattern for microfabrication according to claim 7 of the present application, which is subsequent to FIG. 6;
In addition, it is a process drawing of another embodiment (fifth embodiment) of the fine processing method according to claim 8.

[Explanation of symbols]

 10, 100: Base 11: Wafer 13: Layers to be finely processed 13a, 13b: Processed W layer pattern 14: Resist layer 14a, 14b: Resist pattern 15: Polysilane (polysiloxane) layer 15a: Exposure part (negative) Pattern) 15b: unexposed portion (positive pattern)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/30 569H

Claims (12)

[Claims] 1. A step of providing a polysilane layer made of polysilane on the lower surface, and a step of selectively exposing the polysilane layer in an oxygen-containing atmosphere to change an exposed portion of the polysilane layer from the polysilane to polysiloxane. And a step of removing the unexposed portion of the polysilane layer by performing plasma etching using an acid gas, the method for forming a pattern for fine processing. 2. The method for forming a microfabrication pattern according to claim 1, wherein the exposure is selected from UV light, Xe—Cl excimer laser, KrF excimer laser, ArF excimer laser, and F ₂ laser. A method for forming a pattern for microfabrication, which is performed by light exposure using one of them as an exposure source. 3. A step of providing a polysilane layer made of polysilane on the lower surface, and a step of selectively exposing the polysilane layer in an oxygen-containing atmosphere to change the exposed portion of the polysilane layer from the polysilane to polysiloxane. A step of removing the unexposed portion of the polysilane layer by performing plasma etching using an acid gas to form the exposed portion as a pattern, and etching the pattern using the pattern as a mask A microfabrication method comprising a step of machining. 4. The fine processing method according to claim 3, wherein the exposure is UV light, Xe—Cl excimer laser,
A fine processing method characterized by performing light exposure using one selected from a KrF excimer laser, an ArF excimer laser, and an F ₂ laser as an exposure source. 5. A step of providing a polysilane layer made of polysilane on the lower surface, and a step of selectively exposing the polysilane layer with an O ₂ ⁺ ion beam to change the exposed portion of the polysilane layer from the polysilane to polysiloxane. And a step of removing an unexposed portion of the polysilane layer by performing plasma etching using an acid gas, a method for forming a pattern for fine processing. 6. A step of providing a polysilane layer made of polysilane on the lower surface, and a step of selectively exposing the polysilane layer with an O ₂ ⁺ ion beam to change the exposed portion of the polysilane layer from the polysilane to polysiloxane. And a step of removing the unexposed portion of the polysilane layer by performing plasma etching using an acid gas to form the exposed portion as a pattern, and etching the pattern using the pattern as a mask A microfabrication method comprising a step of machining. 7. A step of providing a polysilane layer made of polysilane on the lower surface, and the polysilane layer is selectively exposed by using one selected from a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam. A method for forming a pattern for microfabrication, comprising: 8. A step of providing a polysilane layer made of polysilane on the lower surface, and the polysilane layer is selectively exposed by using one selected from a hydrogen halide molecular beam, a halogen ion beam, and a hydrogen ion beam. Thereby, a step of removing the exposed portion of the polysilane layer to leave an unexposed portion as a pattern, a step of exposing the pattern to the entire surface in an oxygen-containing atmosphere, and an etching using the pattern as a mask And a step of finely processing the underlayer. 9. The method for forming a pattern for fine processing according to claim 1, 5 or 7, wherein the base is a substrate, and a metal layer provided on the substrate and to be finely processed. A method for forming a pattern for microfabrication, comprising a resist layer. 10. The microfabrication method according to claim 3, wherein the underlayer comprises a substrate and a metal layer or a resist layer to be microfabricated and provided on the substrate. And a fine processing method. 11. The method for forming a pattern for fine processing according to claim 1, wherein the polysilane layer is provided by plasma polymerization. Method. 12. The microfabrication method according to claim 3, wherein the polysilane layer is provided by plasma polymerization.