JP3410968B2 - Pattern forming method and photosensitive composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for forming a pattern on the surface of a layer to be processed such as a wafer.

[0002]

2. Description of the Related Art Manufacturing processes for semiconductor devices and liquid crystal display devices include many steps for forming a pattern on a wafer or a film to be processed, that is, a layer to be processed. Usually, patterning of the layer to be processed is performed as follows. That is, first, a photosensitive resin film (resist film) is formed on the layer to be processed, the resin film is subjected to pattern exposure, and then a resist pattern is formed through a developing process such as wet development. Further, patterning is performed by etching the layer to be processed using this resist pattern as an etching mask. However, when the resist film is developed by wet development, the obtained resist pattern causes swelling, which causes a problem of reduced resolution.

Further, it is also practiced to impart dry etching resistance by introducing a silylating agent into a predetermined region of the resist film. In this case, first, an organic film having active hydrogen is formed as a resist film on the layer to be processed, the resist film is subjected to pattern exposure, and exposed to an atmosphere containing a silylating agent while heating. This is a method in which silicon is introduced into the exposed or unexposed portion of the resist film surface and the unsilylated portion is removed by etching with oxygen plasma using the silylated portion as an etching mask. However, there is a problem that the silylating agent is difficult to penetrate into the organic film.

Further, after forming a polysilane film on the layer to be processed and performing pattern exposure to generate siloxane bonds in the exposed portion, the unexposed portion of the polysilane film is exposed to HBr, Cl ₂
A method of etching away with gas has been reported. This method has a problem that the etching selection ratio between the exposed and unexposed portions of the polysilane film cannot be high.

[0005]

As described above, although a method of accurately patterning a layer to be processed is desired, a method and material for forming a mask (pattern) necessary for that have not yet been obtained. is the current situation.

[0006]

Therefore , an object of the present invention is to provide a photosensitive composition capable of forming a resist pattern with good dimensional accuracy, which is preferably used for patterning a layer to be processed.

[0008]

In order to solve the above problems, the present invention provides a repeating unit represented by the following general formula (2).
A silicon compound having a unit and an acid by irradiation with light
Provided is a photosensitive composition containing a generating compound .

[Chemical 4] (In the general formula (2), P is an acid represented by the following general formula.
It reacts with and decomposes to form carboxyl groups
Is a group that is solubilized in an alkaline aqueous solution, and Z is a hydrogen source.
Child, substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms,
Indicates an aromatic hydrocarbon group. )

[Chemical 5]

[0009]

[0010]

[0011]

[0012]

[0013]

The present invention will be described in detail below.

The first pattern forming method of the present invention comprises a step of forming an organic silicon film containing a silicon compound having a silicon-silicon bond in the main chain on a layer to be processed, and pattern exposure of the organic silicon film. And a step of forming a siloxane bond in the exposed portion of the organic silicon film, and a reducing substance is contacted with the exposed organic silicon film to form a film of the reduced substance on the unexposed portion of the organic silicon film. Selectively forming a layer, a step of etching the organic silicon film with the film made of the reduced substance as a mask to form an organic silicon film pattern, and a layer to be processed with the organic silicon film pattern as a mask. And a step of etching.

FIG. 1 is a process sectional view showing an example of the first pattern forming method.

First, as shown in FIG. 1A, an organic silicon film 3 is formed on a layer 2 to be processed formed on a substrate 1.

In the present invention, the layer to be processed 2 is not particularly limited, and may be, for example, a positive resist containing quinonediazide and a novolac resin, polystyrene, polymethylmethacrylate, polyvinylphenol, polyester, polyvinylalcohol, polyester, polypropylene. , Polybutadiene, polyvinyl acetate, polyimide, phenol resin, carbon film, electrode material, insulating material, and wiring material wafer.

The organosilicon film 3 formed on the layer to be processed 2 contains a silicon compound having a silicon-silicon bond in its main chain, and examples of such a compound include those shown below.

[0020]

[Chemical 1]

[0021]

[Chemical 2]

[0022]

[Chemical 3]

[0023]

[Chemical 4]

[0024]

[Chemical 5]

[0025]

[Chemical 6]

[0026]

[Chemical 7]

[0027]

[Chemical 8]

[0028]

[Chemical 9]

[0029]

[Chemical 10]

[0030]

[Chemical 11]

[0031]

[Chemical 12]

[0032]

[Chemical 13]

[0033]

[Chemical 14]

[0034]

[Chemical 15]

These compounds may be three-dimensionally bonded or may be copolymerized with each other. Further, it may be a copolymer with a carbon polymer or a graft polymer. The molecular weight of these silicon compounds is not particularly limited, but is 500 to
It is preferably 100,000, and 1,000 to 5
More preferably, it is 10,000. If it is less than 500, film formation becomes difficult, while if it exceeds 100,000, the solubility of the polymer may be significantly reduced.

The silicon compound as described above is not limited to one kind, and several kinds of silicon compounds can be mixed and used. Further, if necessary, a thermal polymerization inhibitor for increasing storage stability, an adhesion improver for improving adhesion to the substrate, etc. may be added.

Among the above silicon compounds,
When a hydrogen atom bonded to a silicon atom of the main chain is used, it is preferable to add a crosslinking agent. As the cross-linking agent, an organic substance having multiple bonds can be used.
The organic substance having a multiple bond is a compound having a double bond or a triple bond, more specifically, a compound having a vinyl group, an acryl group, an aryl group, an imide group, an acetylenyl group, or the like. The organic substance having such a multiple bond may be used in any state of a monomer, an oligomer and a polymer.

The organic compound having such a multiple bond causes an addition reaction with the Si—H bond of the silicon compound by heat or light to crosslink the silicon compound. The organic substance having multiple bonds may be self-polymerized. Specific examples of organic substances having multiple bonds are shown below.

[0039]

[Chemical 16]

[0040]

[Chemical 17]

[0041]

[Chemical 18]

[0042]

[Chemical 19]

[0043]

[Chemical 20]

[0044]

[Chemical 21]

[0045]

[Chemical formula 22]

[0046]

[Chemical formula 23]

[0047]

[Chemical formula 24]

[0048]

[Chemical 25]

As described above, when the organic compound having multiple bonds is mixed with the silicon compound, a radical generator or an acid generator may be added as a catalyst. These radical generators or acid generators play a role of assisting addition reaction or self-polymerization of an organic substance having a multiple bond with Si-H.

Examples of the radical generator include azo compounds (for example, azobisisobutyronitrile), peroxides, alkyl aryl ketones, silyl peroxides and organic halides. The radical generator decomposes an O—O bond or a C—C bond in the molecule by light irradiation or heating to generate a radical. Examples of the radical generator include those shown below.

[0051]

[Chemical formula 26]

When such an oxide is used, the oxide is contained in the solution material of the organic silicon film. The oxide content is 0.01 with respect to 100 parts by weight of the silicon compound.
It is preferably -50 parts by weight, more preferably 1-20 parts by weight.

In forming the organic silicon film 3 on the layer 2 to be processed in the method of the present invention, processes such as spin coating, vapor deposition and CVD can be applied. In the case of spin coating, a polymer solution prepared by dissolving the above components in a predetermined organic solvent is used. The solvent is not particularly limited, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cellosolve, methyl cellosolve acetate, ethyl acetate, butyl acetate, isoamyl acetate, toluene, xylene, anisole, octane, paraffin,
Examples include ketone-based, ester-based, ether-based polar solutions such as isoper and non-polar solutions. The concentration of the solvent is not particularly limited, but is preferably 0.1 to 50% by weight.

The thickness of the organic silicon film 3 is 0.001 μm.
The thickness is preferably 10 μm. If it is less than 0.001 μm, it becomes difficult to secure mask resistance,
On the other hand, if it exceeds 10 μm, it may be difficult to form an etching pattern.

The organic silicon film 3 thus formed is subjected to pattern exposure as shown in FIG. 1A to photo-oxidize the exposed portion of the organic silicon film. Exposure light 4
For example, a mercury lamp, XeF (351 nm), X
eCl (308 nm), KrF (248 nm), KrC
l (222 nm), ArF (193 nm), F ₂ (15
1 nm), electron beam, ion beam, and X-ray can be used.

By irradiating the organosilicon film 3 with these energy rays, first, the Si--Si bond in the organosilicon film in the exposed portion is cleaved, so that oxygen molecules, oxidizing components, and air in the silicon film are exposed. It is oxidized by binding with oxygen molecules inside. Thus, the exposed portion 3a of the silicon film
Si-O-Si bond is selectively generated in the. In some cases, in order to stabilize the oxide film, it may be 80 to 20 after exposure.
You may heat at about 0 degreeC. Polysilane has a reducing power, but when it is oxidized into siloxane, the reducing power disappears.

When polysilane having the reducing power of the exposed portion 3a disappeared and the reducing power remaining only in the unexposed portion 3b is brought into contact with a colloidal solution of a palladium salt or a tin salt or an alcohol solution, the unexposed portion 3b Only palladium and tin are deposited.

Further, by contacting a phosphate containing a reducing substance such as nickel ion, copper ion, cobalt ion, silver ion, gold ion or the like and an aqueous solution of formalin, nickel on the unexposed portion of the polysilane film 3b, A metal such as copper, cobalt, silver, or gold, that is, a reduced substance is deposited to form a film (metal film) 5 made of the reduced substance as shown in FIG. 1B. A metal such as silver nitrate that is easily reduced by the reducing action of polysilane can be deposited without using a catalyst.

In this step, an oxygen source for converting at least a part of silicon-silicon bonds in the exposed portion of the organic silicon film into siloxane bonds is required in the system. As the oxygen source, oxygen gas, oxides, and the peroxides (compound [4-
1] to [4-12]) can be used. Si-S
Oxidation of the i-bond may occur during exposure, or it may be oxidized after exposure by contact with an oxygen source in vacuum or substantially oxygen free. The content of the oxide as described above is 0.
The amount is 01 to 50 parts by weight, preferably 1 to 20 parts by weight.
These oxides can be used as a mixture of several kinds.

Using the generated metal film 5 as a mask,
As shown in FIG. 1C, the exposed portion 3a of the polysilane film is removed by etching. For the etching, for example, a reactive plasma etching method, an IPC etching method,
Alternatively, any method such as an ECR plasma etching method, a magnetron reactive plasma etching method, and an electron beam plasma etching method can be adopted.

In this way, the processed layer 2 is processed by etching as shown in FIG. 1D using the organic silicon film pattern 3b and the metal film 5 as a mask. The source gas at this time can be appropriately selected according to the material of the layer to be processed 2, and for example, halogen-based gas or oxygen-based gas is selected. When etching a layer to be processed made of an oxide film or a nitride film, a dry etching method using a fluorine-based gas as a source gas is preferable. Specific examples of such a source gas include SF ₆ , NF ₃ , CF ₄ , and CHF.
₃ , C ₂ F ₆ , C ₃ F ₈ , C ₂ F _{2 and the} like. These source gases include hydrogen, CO, or A
A gas such as r may be added for use.

When the layer 2 to be processed is made of an organic polymer, oxygen reactive ion etching using oxygen plasma is effective.

Finally, the organosilicon film pattern 3b is peeled off by plasma etching with a halogen-based gas, wet etching, etc., and the patterned layer 2a to be processed is obtained as shown in FIG. 1 (e).

According to the present invention, a compound having a high etching mask property with respect to the organic silicon layer can be selectively formed only in the unexposed portion, so that the organic silicon layer is effectively anisotropically etched. be able to. This method can obtain a rectangular pattern having a high aspect ratio as compared with the conventional method of exposing and developing an organic resist.

The second pattern forming method of the present invention comprises a step of forming an organosilicon film containing a silicon compound having a silicon-silicon bond in the main chain on the layer to be processed, and the step of forming the organosilicon film. A step of performing pattern exposure under a substantially inert gas to form a portion having a Si—C bond in an exposed portion of the organic silicon film, and the portion having the Si—C bond as a mask To form an organic silicon film pattern, and a step of etching the layer to be processed using the organic silicon film pattern as a mask.

The second pattern forming method of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a process sectional view showing an example of the second pattern forming method of the present invention.

First, as shown in FIG. 2A, an organic silicon film 3 is formed on a layer 2 to be processed formed on a substrate 1.

As the layer 2 to be processed, the same ones as mentioned above can be mentioned. The organic silicon film 3 can be formed on the layer to be processed 2 by using the same material as described above and the same method as described above.

The formed organic silicon film 3 is subjected to pattern exposure as shown in FIG. 2A. In the second pattern forming method of the present invention, this pattern exposure is substantially performed. It is carried out in an inert gas atmosphere, that is, in the absence of oxygen. As the exposure light 4, for example, a mercury lamp,
XeF (351 nm), XeCl (308 nm), Kr
F (248 nm), KrCl (222 nm), ArF
(193 nm), F ₂ (151 nm), electron beam, ion beam, X-ray and the like can be used. A heating step at about 80 to 200 ° C. may be added during or after the exposure.

By irradiating the organosilicon film 3 with these energy rays in a substantially inert gas atmosphere, first, the Si--S in the exposed portion of the organosilicon film is exposed.
When the i-bond is cleaved, S--C--S
i-bonding occurs selectively. Thus, in the organosilicon film after exposure, an unexposed portion where Si--Si bonds remain,
Selectivity for etching occurs in the exposed portion where the Si-C-Si bond is generated. Note that oxygen may be mixed in Si—C—Si to the extent that etching selectivity is not hindered.

Si-C formed on the exposed portion of the organic silicon film
By etching the organic silicon film using the —Si bond portion as a mask, an organic silicon film pattern 3c is formed as shown in FIG. 2B. In etching the organic silicon film, reactive plasma etching,
A method similar to the case of the first pattern forming method such as IPC etching can be adopted.

Then, using the organic silicon film pattern 3c as a mask, the layer 2 to be processed is etched as shown in FIG. 2C in the same manner as in the case of the first pattern forming method. The silicon film pattern 3c is peeled off by the same method as described above to obtain the patterned layer 2a to be processed as shown in FIG. 2 (d).

According to the present invention, a compound having a high etching mask property with respect to the organic silicon layer can be selectively formed only in the exposed portion instead of isotropic wet development, so that the organic silicon layer can be effectively used. Can be anisotropically dry-etched. This method can obtain a rectangular pattern having a high aspect ratio as compared with the conventional method of exposing and developing an organic resist.

The third pattern forming method of the present invention comprises a step of forming an organic silicon film containing a silicon compound having a silicon-silicon bond in the main chain on the layer to be processed, and the step of forming an organic silicon film on the organic silicon film. A step of forming a resist film having a Si-O-Si bond and capable of being alkali-developed, and pattern exposure and development with an alkaline aqueous solution are performed on the resist film to form a pattern having a Si-O bond on the organic silicon film. Forming step, a step of etching the organic silicon film by using the portion having the Si-O bond as a mask to form an organic silicon film pattern, and a step of etching a processed layer by using the organic silicon film pattern as a mask And.

The third pattern forming method of the present invention will be described in detail with reference to the drawings.

3 and 4 are process sectional views showing an example of the third pattern forming method of the present invention.

First, as shown in FIG. 3A, the organosilicon film 3 is formed on the layer 2 to be processed formed on the substrate 1.

As the layer 2 to be processed, the same ones as mentioned above can be mentioned. The organic silicon film 3 can be formed on the layer to be processed 2 by using the same material as described above and the same method as described above.

On the organic silicon film 3 thus formed, FIG.
As shown in (b), an alkali developable resist film 6 having a Si—O—Si bond is formed. Si-O-Si
The alkali-developable resist having a bond is Si-
It is a photosensitive composition having an O—Si bond in its main chain or side chain, and may be either a chemically amplified resist or a non-chemically amplified resist.

The chemically amplified resist can be composed of, for example, a polymer having a repeating unit represented by the following general formula (1) and a photo-acid generator capable of generating an acid upon irradiation with actinic radiation.

[0082]

[Chemical 27]

In the above general formula (1), X is a group which is decomposed by an acid to generate a carboxylic acid, a phenol group and a silanol group and is solubilized in an alkaline aqueous solution. Specific examples include the groups shown below.

[0084]

[Chemical 28]

Y represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group. Specific examples include the groups shown below.

[0086]

[Chemical 29]

Examples of the polymer having the repeating unit represented by the general formula (1) include those shown below.

[0088]

[Chemical 30]

Further, it may be a copolymer obtained by copolymerizing any of these repeating units.

The molecular weight of the above-mentioned polymer used in the third pattern forming method of the present invention is not particularly limited, but is usually about 500 to 100,000. Also,
The content is usually 50 to 99.9% with respect to the resist.
It is a degree.

Examples of the photo-acid generator which is another component of the chemically amplified resist include those shown below.

[0092]

[Chemical 31]

[0093]

[Chemical 32]

[0094]

[Chemical 33]

[0095]

[Chemical 34]

[0096]

[Chemical 35]

[0097]

[Chemical 36]

[0098]

[Chemical 37]

[0099]

[Chemical 38]

[0100]

[Chemical Formula 39]

[0101]

[Chemical 40]

The photo-acid generator as described above is usually blended in a proportion of 0.1 to 10% with respect to the polymer.

In addition to the polymer represented by the general formula (1) and the photo-acid generator, the chemically amplified resist may further contain a polymer soluble in an alkaline aqueous solution. Specific examples thereof include a phenol resin, a siloxane resin substituted with phenol, a siloxane resin substituted with carboxylic acid, a polyacrylic acid derivative, a polymethacrylic acid derivative, and a silanol-containing siloxane resin. When such an alkali-soluble polymer is blended, the blending amount can be appropriately determined according to the solubility in an alkaline aqueous solution, the etching selection ratio, etc., but is usually about 1 to 50 parts by weight with respect to the silicon polymer. is there.

On the other hand, the non-chemically amplified resist can be composed of a photosensitizer and an alkali-soluble resin. Examples of the photosensitizer include naphthoquinonediazide and azide compounds, and examples of the alkali-soluble resin include compounds represented by the following chemical formula.

[0105]

[Chemical 41]

When a non-chemically amplified resist is used, the photosensitizer is usually added in a proportion of about 1 to 30% with respect to the alkali-soluble resin.

The chemically amplified resist or the non-chemically amplified resist as described above is applied on an organic silicon film by, for example, a spin coating method and heated at about 50 to 130 ° C. to have a film thickness of 0.1 to 2 μm. A resist film is formed to some extent.

The resist film 6 and the organic silicon film 3 thus obtained are subjected to pattern exposure as shown in FIG. 3 (b). As the exposure light 4, for example, a mercury lamp, XeF (35
1 nm), XeCl (308 nm), KrF (248n)
m), KrCl (222 nm), ArF (193n)
m), F ₂ (151 nm), electron beam, ion beam, X-ray and the like can be used.

In the exposed portion of the resist film 6, Si—O bonds are formed.

The exposed resist film 6 is baked at 50 to 150 ° C. for about 0.1 to 5 minutes if necessary, and is developed with an alkaline aqueous solution, so that the pattern shown in FIG.
A siloxane-based pattern 6a as shown in (c) is formed. As the alkaline aqueous solution that can be used here,
For example, tetramethylammonium hydroxide solution,
Examples include choline, sodium hydroxide, potassium hydroxide and the like.

Although an example in which a negative resist is used is described here, when a positive resist is used, an unexposed portion of the resist film 6 remains after development and a siloxane-based pattern is formed. It is formed.

By using the siloxane-based pattern 6a thus formed and, optionally, the Si—O bond portion formed in the organic silicon film 3 as a mask, the organic silicon film is etched to form a pattern shown in FIG. ), The organosilicon film pattern 3a is formed. For the etching of the organic silicon film, the same method as in the case of the first pattern forming method such as reactive plasma etching and IPC etching can be adopted.

Then, using the organic silicon film pattern 3a as a mask, the layer 2 to be processed is etched as shown in FIG. 4B in the same manner as in the case of the first pattern forming method. The silicon film pattern 3a is peeled off by the same method as described above to obtain the patterned layer 2a to be processed as shown in FIG. 4 (c).

According to the present invention, a compound having a Si—O bond having a high etching mask property with respect to an organic silicon layer can be formed as a thin film only in an unexposed area or an exposed area, so that the organic silicon layer can be effectively used. Can be anisotropically etched, and a rectangular pattern with a high aspect ratio can be obtained. A rectangular pattern having a high aspect ratio can be obtained as compared with the case of exposing and developing a conventional organic resist that does not have a high etching selectivity.

The fourth pattern forming method of the present invention comprises a step of forming an organic silicon film containing a silicon compound having a silicon-silicon bond in the main chain on the layer to be processed, and pattern exposure of the organic silicon film. And forming a siloxane bond on the exposed portion of the organosilicon film, and bringing the organosilicon compound into contact with the organosilicon film to selectively form a Si—O bond on or in the exposed portion of the organosilicon film. A step of forming an organic silicon film pattern by etching the organic silicon film using the portion having the Si—O bond as a mask, and a step of etching the layer to be processed using the organic silicon film pattern as a mask. And.

The fourth pattern forming method of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a process sectional view showing an example of the fourth pattern forming method of the present invention.

First, as shown in FIG. 5A, the organosilicon film 3 is formed on the layer 2 to be processed formed on the substrate 1.

As the layer 2 to be processed, the same ones as mentioned above can be mentioned. The organic silicon film 3 can be formed on the layer to be processed 2 by using the same material as described above and the same method as described above.

The obtained organosilicon film 3 is shown in FIG.
Pattern exposure is performed as shown in FIG. As the exposure light 4, for example, a mercury lamp, XeF (351 nm), Xe
Cl (308 nm), KrF (248 nm), KrCl
(222 nm), ArF (193 nm), F ₂ (151
nm), electron beams, ion beams, X-rays, and the like can be used.

By irradiating the organosilicon film 3 with these energy rays, first, the Si--Si bond in the organosilicon film in the exposed portion is cleaved, so that oxygen molecules, oxidizing components, and air in the silicon film are exposed. It is oxidized by binding with oxygen molecules inside. Thus, Si—O—Si bonds and Si—OH bonds are selectively generated in the exposed portion of the silicon film. In some cases, to stabilize the oxide film,
After exposure, heating at about 50 to 200 ° C. may be performed.

As described above, in this step, an oxygen source for converting at least a part of silicon-silicon bonds in the exposed portion of the organic silicon film into siloxane bonds or Si-OH bonds is required in the system. As an oxygen source, oxygen gas,
The oxides and the peroxides (compounds [4-1] to [4-12]) listed as the radical generators described above can be used. Oxidation of the Si-Si bond may occur during exposure or it may be post-exposure oxidized by contacting with an oxygen source in vacuum or substantially oxygen free. The content of the oxide as described above is 0.01 to 50 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the silicon compound. These oxides can be used as a mixture of several kinds.

Thereafter, an organosilicon compound is selectively adsorbed or reacted on the exposed portion by a gas phase or liquid phase reaction,
The Si—O containing film 7 as shown in FIG. 5B is formed.
The organosilicon compound to be adsorbed is, for example,
Low molecular weight siloxane-containing compounds, silazane-containing compounds such as (CH ₃ ) ₃ SiNHSi (CH ₃ ) ₃ ,
(CH ₃ ) ₃ SiNH ₂ , ((CH ₃ ) ₃ Si) ₃ N,
(CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ , (CH ₃ ) ₂ S
iHNHSiH (CH _{3) 2} and the like. Thus, in the organic silicon film 3, Si in the unexposed portion and the exposed portion
It is possible to increase the ratio of —O—Si bond and Si—Si bond, and it is possible to increase the etching selection ratio.

Using the Si—O containing film 7 thus formed as a mask, the organic silicon film is etched to form an organic silicon film pattern 3d as shown in FIG. 5C. For the etching of the organic silicon film, the same method as in the case of the first pattern forming method such as reactive plasma etching and IPC etching can be adopted.

Then, using the organic silicon film pattern 3d as a mask, the layer 2 to be processed is etched as shown in FIG. 5D in the same manner as in the case of the first pattern forming method. The silicon film pattern 3d is peeled off in the same manner as described above to obtain the patterned layer 2a to be processed as shown in FIG. 5 (e).

According to the present invention, a siloxane compound having a high etching mask property with respect to an organic silicon layer can be selectively formed only in an exposed portion, so that the organic silicon layer is effectively anisotropically etched. be able to. Compared with the conventional method of partially oxidizing polysilane to obtain a pattern, this method can have a large etching selection ratio and can obtain a rectangular pattern with a high aspect ratio.

The fifth pattern forming method of the present invention comprises the steps of forming an organosilicon film containing a silicon compound having a silicon-silicon bond in the main chain on the layer to be processed, and reducing the organosilicon film. A step of contacting a substance to form a film made of a reduced substance on the entire surface of the organosilicon film; a step of forming a resist film on the film made of the reduced substance; A step of performing exposure and development to obtain a resist pattern, a step of patterning the film made of the reducing substance by using the obtained resist pattern as a mask, and a mask of the patterned film and resist pattern made of the reducing substance. Patterning the organic silicon film as a film, a film made of a patterned reducing substance and an organic silicon film, and a resist pattern As a mask, and a step of etching the layer to be processed.

The fifth pattern forming method of the present invention will be described in detail with reference to the drawings.

6 and 7 are process sectional views showing an example of the fifth pattern forming method of the present invention.

First, as shown in FIG. 6A, the organosilicon film 3 is formed on the layer 2 to be processed formed on the substrate 1.

As the layer 2 to be processed, the same ones as described above can be mentioned. The organic silicon film 3 can be formed on the layer to be processed 2 by using the same material as described above and the same method as described above.

A reducing substance is brought into contact with the formed organosilicon film 3 to form a film 5 of the reduced substance on the entire surface of the organosilicon film 3 as shown in FIG. 6B.
Here, examples of the reducing substance include those described in the first pattern forming method described above, and the film (metal film) 5 made of the reduced substance can be formed by the same method as described above.

The metal film 5 acts as an antireflection film and a conductive thin film, and its film thickness is desired to be a thin film that does not affect etching performed in a later step. Specifically, it is preferably about 10 to 5000 angstroms. If it is less than 10 Å, the antireflection effect is not sufficient, while if it exceeds 5000 Å, etching may be difficult.

On the metal film 5 thus formed, as shown in FIG.
As shown in, a resist film 6 is formed. Resist film 6
Can be formed by the same method as described above using the chemically amplified resist or the non-chemically amplified resist as described in the third pattern forming method.

The thickness of the resist film 6 is 0.1-5.
It is preferably about μm. If it is less than 0.1 μm, the etching resistance is not sufficient, while if it exceeds 5 μm, a fine pattern may not be formed by light exposure.

The resist film 6 thus obtained is shown in FIG.
Pattern exposure is performed as shown in FIG. As the exposure light 4, for example, a mercury lamp, XeF (351 nm), XeCl
(308 nm), KrF (248 nm), KrCl (2
22 nm), ArF (193 nm), F ₂ (151n)
m), electron beams, ion beams, X-rays and the like can be used.

The resist film 6 after exposure is baked at 50 to 150 ° C. for about 0.1 to 5 minutes and developed with a predetermined developing solution, as shown in FIG.
A resist pattern 6a as shown in (d) is formed. Examples of the developer that can be used here include tetramethylammonium hydroxide solution, alkaline aqueous solutions such as choline, sodium hydroxide, and potassium hydroxide.

Resist pattern 6a thus formed
By using the as a mask to etch the metal film 5, a metal film pattern 5a is formed as shown in FIG. For etching the metal film 5, for example, plasma etching of halogens or wet etching can be adopted.

By using the formed metal film pattern 5a and resist pattern 6a as a mask to etch the organic silicon film, an organic silicon film pattern 3b is formed as shown in FIG. 7B. For the etching of the organic silicon film, the same method as in the case of the first pattern forming method such as reactive plasma etching and IPC etching can be adopted. A halogen-based gas such as chlorine-based, fluorine-based, or HBr is effective as a source gas for etching the organic silicon film 3.

Then, using the organic silicon film pattern 3b as a mask, the layer 2 to be processed is etched as shown in FIG. 7C in the same manner as in the case of the first pattern forming method. The silicon film pattern 3b is peeled off in the same manner as described above to obtain the patterned layer 2a to be processed as shown in FIG. 7 (d).

According to the present invention, an effective antireflection effect can be obtained with a thin film made of a substance having a high antireflection effect. Therefore, a rectangular pattern having a high aspect ratio can be obtained as compared with the conventional method of exposing and developing a resist.

Next, the photosensitive composition of the present invention will be described in detail.

The composition of the present invention is represented by the following general formula (2).
A silicon compound having a repeating unit , and a compound capable of generating an acid upon irradiation with light.

[0144]

[0145]

[Chemical 42]

In the above general formula (2), P is a group which is decomposed by an acid and solubilized in an alkaline aqueous solution, and specific examples are shown below.

[0147]

[Chemical 43]

Z represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group. A specific example is shown below.

[0149]

[Chemical 44]

Examples of silicon compounds having the repeating unit represented by the above general formula (2) are shown below.

[0151]

[Chemical formula 45]

A copolymer obtained by copolymerizing any of these repeating units may be used. Furthermore, a copolymer of these repeating units and a silicon compound having a silicon-silicon bond as described above can also be blended as a component of the photosensitive composition of the present invention.

By reacting with such an acid and decomposing
Having a side chain having a group that produces a carboxyl group , Si-Si
The silicon compound having a bond as a main chain has a molecular weight of 500 to 1
It is preferably about 0,000, and 1000 to 1
More preferably, it is about 10,000. If it is less than 500, it becomes difficult to form a film, while if it exceeds 100,000, the alkali solubility may decrease.

As the photo-acid generator which generates an acid upon irradiation with light, those mentioned above can be used.

In the photosensitive composition of the present invention, the amount of the photo-acid generator compounded is 0.01 parts by weight or more with respect to the polymer.
The amount is preferably not more than 0.1 part by weight, more than 0.1 part by weight
It is more preferable that the amount is 0 parts by weight or less. If the amount is less than 0.1 parts by weight, the development becomes difficult, while if it exceeds 20 parts by weight, the film forming ability may be deteriorated.

In addition to the above-mentioned components, the photosensitive composition of the present invention may contain a polymer soluble in an aqueous alkaline solution. Examples of the alkali-soluble polymer include a phenol resin, a siloxane resin substituted with a phenol resin, a siloxane resin substituted with a carboxylic acid, a polyacrylic acid derivative, a polymethacrylic acid derivative, and a silanol-containing siloxane resin. When the alkali-soluble resin is blended, the blending amount can be appropriately determined depending on the alkali-solubility, etching resistance, etc., but is 1 to 5 relative to the silicon polymer.
It is preferably about 0 parts by weight.

The photosensitive composition of the present invention reacts with an acid to form
A side chain having a group that forms a carboxyl group by solving , a silicon compound having a silicon-silicon bond as a main chain,
It can be prepared by dissolving a photo-acid generator and, if necessary, an alkali-soluble resin in an organic solvent. Examples of the solvent that can be used here include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cellosolve, methyl cellosolve acetate, ethyl acetate, butyl acetate, isoamyl acetate, toluene, xylene, anisole, octane, paraffin, and isoper. Examples include system-based, ester-based, ether-based polar solutions and non-polar solutions. The concentration of the solvent is not particularly limited, but is preferably 0.1 to 50% by weight.

The photosensitive composition of the present invention thus prepared can be preferably used for fine processing of a layer to be processed formed on a semiconductor substrate. Hereinafter, the pattern forming method using the photosensitive composition of the present invention will be described in detail with reference to the drawings.

FIG. 8 is a process sectional view showing an example of a pattern forming method using the photosensitive composition of the present invention.

First, as shown in FIG. 8A, the photosensitive composition of the present invention is applied onto the layer 2 to be processed formed on the substrate 1 and heat-treated at about 50 to 150 ° C. The organic silicon film 11 is formed. As the layer to be processed 2, the same ones as mentioned above can be mentioned. Further, the thickness of the organic silicon film 11 is
It can be appropriately determined within the range of 0.001 μm to 10 μm.

The obtained organosilicon film 11 is shown in FIG.
Pattern exposure is performed as shown in FIG. As the exposure light 4, for example, a mercury lamp, XeF (351 nm), Xe
Cl (308 nm), KrF (248 nm), KrCl
(222 nm), ArF (193 nm), F ₂ (151
nm), electron beams, ion beams, X-rays, and the like can be used.

By performing such exposure, Si—O bond is formed in the exposed portion 11a of the organic silicon 11.

For the organosilicon 11 after exposure , 50
By baking at ˜150 ° C. for about 0.1 to 5 minutes and developing with an alkaline aqueous solution, a siloxane-based pattern 11a as shown in FIG. 8C is formed. As the alkaline aqueous solution that can be used here, for example,
Tetramethylammonium hydroxide solution, choline,
Examples thereof include sodium hydroxide and potassium hydroxide.

Using the siloxane-based pattern 11a thus formed as a mask, the layer 2 to be processed is etched as shown in FIG. 8D in the same manner as in the case of the first pattern forming method. The siloxane-based pattern 11a is peeled off in the same manner as described above, and the pattern shown in FIG.
A patterned layer 2a to be processed is obtained as shown in (e).

According to the present invention, since the resist pattern can be formed on the layer to be processed with high etching selectivity, the layer to be processed can be processed with high dimensional accuracy and high resolution.

[0166]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in more detail below by showing Examples and Comparative Examples of the present invention, but the present invention is not limited to these Examples.

Example 1 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to obtain 3% by weight.
Xylene solution is prepared.
It was applied on the OG oxide film and heated to form an organosilicon film having a thickness of 0.05 μm.

Then, a KrF excimer laser of 100 mJ / c is applied to the organic silicon film through a predetermined mask.
After irradiation with an exposure amount of m ² , a post-exposure bake was performed at 150 ° C. for 10 minutes.

The organosilicon film after baking was brought into contact with a 10% ethanol solution of palladium nitrate by the paddle method to give 10
After holding for a minute, it was washed with ethanol. Subsequently, an electroless plating solution containing 10% by weight of nickel sulfate was similarly contacted by the paddle method, and only the unexposed portion of the organic silicon film was nickel-plated.

Using the formed nickel plating as a mask, a magnetron type RIE device is used, and a source gas CHF is used.
₃ (45 SCCM), CO (155 SCCM), O
₂ (10 SCCM), excitation power 800W, vacuum degree 40m
Etching was performed under the conditions of Torr to form a 0.15 μm oxide film pattern. The obtained oxide film pattern had a rectangular cross section, and its side wall was also vertical and had a good shape.

Comparative Example 1 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to obtain 3% by weight.
Xylene solution is prepared.
It was applied on the OG oxide film and heated to form an organosilicon film having a thickness of 0.05 μm.

Then, a KrF excimer laser of 100 mJ / c is applied to the organic silicon film through a predetermined mask.
After irradiation with an exposure amount of m2, a post-exposure bake was performed at 150 ° C for 10 minutes.

Using a magnetron type RIE device, the source gas CHF ₃ (45 SCCM), CO (15
5 SCCM), O ₂ (10 SCCM), excitation power 800
An etching was attempted under the conditions of W and a vacuum degree of 40 mTorr, but a pattern could not be formed.

Examples 2 to 10 Patterns were formed as shown in Table 1 below.

[0177]

[Table 1]

The abbreviations representing polysilanes in Table 1 are as follows.

PS-1: polyphenylmethylsilane PS-2: polyphenylhydrosilane PS-3: polymethylhydrosilane PS-4: 0.5: 0.5 copolymer PS of polyphenylmethylsilane and polyphenylhydrosilane -5: Polyphenylsilane PS-6: 0.5: 0.5 Copolymer of Polyphenylmethylsilane and Polyphenylsilane As shown in Table 1, the present invention can be used regardless of which silicon compound is used. The processed layer processed by the method of 1. had a rectangular cross section and its sidewall was vertical. Furthermore, it has been found that the silicon compound, the metal film and the layer to be processed can be arbitrarily combined to process the layer to be processed into a good shape by the method of the present invention regardless of the material of the metal film or the layer to be processed. It was

Example 11 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to prepare a 10 wt% xylene solution, which was coated on the SOG oxide film and heated. An organic silicon film having a thickness of 0.5 μm was formed.

Then, this organic silicon film was exposed to a KrF excimer laser at an exposure dose of 100 mJ / cm ^{2 in} a nitrogen atmosphere through a predetermined mask, and then exposed to oxygen at 150 ° C. for 10 minutes. Baking was performed after exposure.

Using a magnetron type RIE device, a source gas HBr (45 SCCM) and an excitation power of 25 were used.
Etching was performed under the conditions of W and the degree of vacuum of 10 mTorr to form an oxide film pattern of 0.15 μm. The obtained oxide film pattern had a rectangular cross section, and its side wall was also vertical and had a good shape.

Comparative Example 2 A SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to prepare a 10 wt% xylene solution, which was coated on the SOG oxide film and heated. An organic silicon film having a thickness of 0.5 μm was formed.

Then, the organosilicon film was exposed to a KrF excimer laser at an exposure dose of 100 mJ / cm ^{2 in} an oxygen atmosphere through a predetermined mask, and then exposed at 150 ° C.
After exposure for 10 minutes, baking was performed.

Using a magnetron type RIE device, a source gas HBr (45 SCCM) and an excitation power of 45 were used.
The etching was attempted under the conditions of W and the degree of vacuum of 10 mTorr, but the oxide film pattern of 0.15 μm could not be formed.

Examples 12 to 20 Patterns were formed as shown in Table 2 below.

[0189]

[Table 2]

The abbreviations for polysilane in Table 2 are as follows.

PS-1: polyphenylmethylsilane PS-2: polyphenylhydrosilane PS-3: polymethylhydrosilane PS-4: 0.5: 0.5 copolymer PS of polyphenylmethylsilane and polyphenylhydrosilane -5: Polyphenylsilane PS-6: 0.5: 0.5 Copolymer of Polyphenylmethylsilane and Polyphenylsilane As shown in Table 2, the present invention can be applied to any silicon compound. The processed layer processed by the method of 1. had a rectangular cross section and its sidewall was vertical. Furthermore, regardless of the material of the metal film or the layer to be processed, etc., it is possible to process the layer to be processed into a good shape by the method of the present invention by arbitrarily combining the silicon compound, the metal film and the layer to be processed. all right.

Example 21 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to obtain 3% by weight.
Xylene solution is prepared.
It was applied on the OG oxide film and heated to form an organic silicon film having a thickness of 0.5 μm.

A polymer represented by the following chemical formula (PS-
11) and the photo-acid generator (PAG-1) were mixed at a ratio of 99: 1 and dissolved in ethyl oxalate to prepare a 10% ethyl oxalate solution to obtain a resist solution (RSO1). . This (RSO1) was applied on the above-mentioned organosilicon film and prebaked at 100 ° C. for 1 minute to form a resist film.

[0195]

[Chemical formula 46]

The obtained resist film was exposed to a KrF excimer laser through a predetermined mask at an exposure amount of 30 mJ / cm ² , and post-exposure baked at 130 ° C. for 10 minutes.

After that, development was carried out for 1 minute with a 2.38% tetramethylammonium hydroxide aqueous solution, and a good pattern was obtained.

Using a magnetron type RIE device, source gas Cl ₂ (40 SCCM) and excitation power 10
When etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr, a polysilane pattern could be obtained.

Using this polysilane pattern as a mask,
Source gas CHF ₃ (45SCCM), CO (155S
CCM), O ₂ (10 SCCM), excitation power 800 W,
Etching was performed under the conditions of a vacuum degree of 40 mTorr.
As a result, a 0.15 μm oxide film pattern is formed,
The obtained oxide film pattern had a rectangular cross section, and its side wall was also vertical and had a good shape.

(Examples 22 to 30) Tables 3 and 4 below.
The patterns were formed as shown in FIG.

[0201]

[Table 3]

[0202]

[Table 4]

The abbreviations for polysilanes in Tables 3 and 4 are as follows.

PS-1: polyphenylmethylsilane PS-2: polyphenylhydrosilane PS-3: polymethylhydrosilane PS-4: 0.5: 0.5 copolymer PS of polyphenylmethylsilane and polyphenylhydrosilane -5: Polyphenylsilane PS-6: 0.5: 0.5 copolymer of polyphenylmethylsilane and polyphenylsilane Also, polysiloxane resists (RSO2) and (R
SO3) is a resist prepared as follows.

(RSO2): A polymer (PS-12) represented by the following chemical formula and a photoacid generator (PAG-2) were mixed at a ratio of 99: 1 and dissolved in a solvent (solv. 1) to give 10%. Was prepared.

[0206]

[Chemical 47]

(RSO3): A polymer (PS-13) represented by the following chemical formula and a photo-acid generator (PAG-3) were mixed at a ratio of 99: 1 and dissolved in a solvent (solv. Was prepared.

[0208]

[Chemical 48]

As shown in Tables 3 and 4, the processed layer processed by the method of the present invention had a rectangular cross section and the side walls thereof were vertical regardless of which silicon compound was used. Furthermore, regardless of the material of the metal film or the layer to be processed, etc., it is possible to process the layer to be processed into a good shape by the method of the present invention by arbitrarily combining the silicon compound, the metal film and the layer to be processed. all right.

Example 31 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to prepare a 20 wt% xylene solution, which was coated on the SOG oxide film and heated. An organic silicon film having a thickness of 0.5 μm was formed.

A KrF excimer laser of 100 mJ / cm ² was applied to this organic silicon film through a predetermined mask.
Immediately after that, it is treated with a vapor of tetramethyldisilazane at 60 ° C. for 5 minutes, and then immediately at 150 ° C.
And baked for 10 minutes.

Using a magnetron type RIE apparatus, this was source gas Cl ₂ (40 SCCM) and excitation power 10
When etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr, a polysilane pattern could be obtained.
Using this polysilane pattern as a mask, the source gas C
HF ₃ (45 SCCM), CO (155 SCCM), O
₂ (10 SCCM), excitation power 800W, vacuum degree 40m
Etching was performed under the conditions of Torr. as a result,
An oxide film pattern having a thickness of 0.15 μm was formed, and the cross section of the obtained oxide film pattern was rectangular, and the side wall thereof was also vertical and had a good shape.

(Example 32) An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, polyphenylsilane (weight average molecular weight of 7,000) was dissolved in xylene to prepare a 30 wt% xylene solution, and this xylene solution was applied on the above SOG oxide film and heated to a thickness. A 0.5 μm thick organosilicon film was formed.

A KrF excimer laser of 100 mJ / cm ^{2 is applied} to this organic silicon film through a predetermined mask.
Immediately after that, it is treated with hexamethyldisilazane vapor for 5 minutes at 60 ° C.
Baking was performed at 0 ° C. for 10 minutes.

Using a magnetron type RIE device, source gas Cl ₂ (40 SCCM) and excitation power 10
When etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr, a polysilane pattern could be obtained.
Using this polysilane pattern as a mask, the source gas C
HF ₃ (45 SCCM), CO (155 SCCM), O
₂ (10 SCCM), excitation power 800W, vacuum degree 40m
Etching was performed under the conditions of Torr. As a result, as a result, an oxide film pattern having a thickness of 0.15 μm was formed, the cross section of the obtained oxide film pattern was rectangular, and the side wall thereof was also vertical and had a good shape.

Example 33 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, a 3: 1 copolymer of polymethylphenylsilane and methylsilane (weight average molecular weight of 10,000) was used.
0) 100 parts by weight, 10 parts by weight of pentaerythritol trimethacrylate, and 5 parts by weight of benzophenone tetracarboxylate tetra-t-butyl peroxide were mixed and dissolved in xylene to prepare a 20% by weight xylene solution. This xylene solution was applied onto the SOG oxide film described above, heated to form an organosilicon film having a thickness of 0.5 μm, and baked at 160 ° C. for 5 minutes to crosslink the polysilane.

A KrF excimer laser of 100 mJ / c was applied to the obtained polysilane film through a predetermined mask.
After exposure with an exposure amount of m ^2, the film was immersed in a hexamethyldisilazane solution for 3 minutes and immediately baked at 150 ° C. for 10 minutes.

Using a magnetron type RIE device, source gas Cl ₂ (40 SCCM) and excitation power 10
When etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr, a polysilane pattern could be obtained.
Using this polysilane pattern as a mask, the source gas C
HF ₃ (45 SCCM), CO (155 SCCM), O
₂ (10 SCCM), excitation power 800W, vacuum degree 40m
Etching was performed under the conditions of Torr. as a result,
An oxide film pattern having a thickness of 0.15 μm was formed, and the cross section of the obtained oxide film pattern was rectangular, and the side wall thereof was also vertical and had a good shape.

Comparative Example 3 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, a 3: 1 copolymer of polymethylphenylsilane and methylsilane (weight average molecular weight 10,000
0) 100 parts by weight, 10 parts by weight of pentaerythritol trimethacrylate, and 5 parts by weight of benzophenone tetracarboxylate tetra-t-butyl peroxide were mixed and dissolved in xylene to prepare a 20% by weight xylene solution. This xylene solution was applied onto the SOG oxide film described above, heated to form an organosilicon film having a thickness of 0.5 μm, and baked at 160 ° C. for 5 minutes to crosslink the polysilane.

A KrF excimer laser of 100 mJ / c was applied to the obtained polysilane film through a predetermined mask.
It was exposed with an exposure amount of m ² .

Using a magnetron type RIE device, source gas Cl ₂ (40 SCCM) and excitation power 10
An etching was tried under the conditions of 0 W and a vacuum degree of 40 mTorr, but a polysilane pattern of 0.15 μm could not be obtained.

Example 34 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, a polymer represented by the following chemical formula (PS-14) and the above-mentioned photo-acid generator (PAG-1) were mixed in a weight ratio of 99: 1 and dissolved in cyclohexanone to prepare an 8% polymer solution. (RPS1) was prepared. This (RPS1) is coated on the SOG oxide film described above,
Prebaking was performed at 0 ° C. for 1 minute to form an organic silicon film having a thickness of 0.5 μm.

[0228]

[Chemical 49]

A KrF excimer laser is applied to the obtained organosilicon film through a predetermined mask at 30 mJ / cm ^2.
After exposure with the exposure amount of 10 ° C., post-exposure baking was performed at 130 ° C. for 10 minutes.

After that, development was carried out for 1 minute with a 2.38% tetramethylammonium hydroxide aqueous solution, and a good polysilane pattern could be formed.

Using this polysilane pattern as a mask, source gas CHF ₃ (45 SCCM), CO (1
55 SCCM), O ₂ (10 SCCM), excitation power 80
Etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr. As a result, an oxide film pattern having a thickness of 0.15 μm was formed, the cross section of the obtained oxide film pattern was rectangular, and the side walls thereof were also vertical and had a good shape.

Example 35 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, the polymer represented by the following chemical formula (PS-15) and the above-mentioned photo-acid generator (PAG-2) were mixed in a weight ratio of 99: 1 and dissolved in cyclohexanone to prepare a 10% polymer solution. (RPS2) was prepared. This (RPS2) is coated on the SOG oxide film described above,
Prebaking was performed at 0 ° C. for 1 minute to form an organic silicon film having a thickness of 0.5 μm.

[0234]

[Chemical 50]

A KrF excimer laser is applied to the obtained organosilicon film through a predetermined mask at 30 mJ / cm ^2.
After exposure with the exposure amount of 10 ° C., post-exposure baking was performed at 130 ° C. for 10 minutes.

After that, development was carried out for 1 minute with a 2.38% tetramethylammonium hydroxide aqueous solution, and a good polysilane pattern could be formed.

Using this polysilane pattern as a mask, source gas CHF ₃ (45 SCCM), CO (1
55 SCCM), O ₂ (10 SCCM), excitation power 80
Etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr. As a result, an oxide film pattern having a thickness of 0.15 μm was formed, the cross section of the obtained oxide film pattern was rectangular, and the side walls thereof were also vertical and had a good shape.

Example 36 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

On the other hand, the polymer represented by the following chemical formula (PS-16) and the above-mentioned photo-acid generator (PAG-1) were mixed in a weight ratio of 99: 1 and dissolved in cyclohexanone to prepare a 6% polymer solution. (RPS3) was prepared. This (RPS3) is applied on the SOG oxide film described above,
Prebaking was performed at 0 ° C. for 1 minute to form an organic silicon film having a thickness of 0.4 μm.

[0240]

[Chemical 51]

A KrF excimer laser was applied to the obtained organosilicon film through a predetermined mask at 30 mJ / cm ^2.
After exposure with the exposure amount of 10 ° C., post-exposure baking was performed at 130 ° C. for 10 minutes.

Then, the film was developed with a 2.38% tetramethylammonium hydroxide aqueous solution for 1 minute, and a good polysilane pattern was obtained.

Using this polysilane pattern as a mask, source gas CHF ₃ (45 SCCM), CO (1
55 SCCM), O ₂ (10 SCCM), excitation power 80
Etching was performed under the conditions of 0 W and a degree of vacuum of 40 mTorr. As a result, an oxide film pattern having a thickness of 0.15 μm was formed, the cross section of the obtained oxide film pattern was rectangular, and the side walls thereof were also vertical and had a good shape.

Example 37 An SOG oxide film having a thickness of 0.5 μm was formed as a layer to be processed on a silicon wafer.

Polymethylphenylsilane (weight average molecular weight 12,000) was dissolved in xylene to prepare a 10 wt% xylene solution, which was coated on the above SOG oxide film and heated to a thickness of 0. An organic silicon film having a thickness of 0.2 μm was formed.

A 10% ethanol solution of palladium nitrate was brought into contact with the obtained organosilicon film by the paddle method, held for 10 minutes, and then washed with ethanol. Then, an electroless plating solution containing 10% of nickel sulfate was similarly contacted by the paddle method to uniformly deposit copper on the polysilane film. As a result, a copper film having a thickness of 0.1 μm was formed. This copper film acts as an antireflection film.

A KrF excimer laser resist is coated on this and baked at 100 ° C. for 1 minute to form a film having a thickness of 0.5.
A μm resist film was formed. A KrF excimer laser is applied to this resist film through a predetermined mask.
After exposing at an exposure dose of 00 mJ / cm ² , 1 at 130 ° C
Bake for a minute.

Then, when the resist film was developed with a 2.38% tetramethylammonium hydroxide aqueous solution, a resist pattern without standing waves could be formed. It is considered that the copper film formed as the lower layer of the resist film worked sufficiently as an antireflection film. This is a magnetron type RIE
A polysilane pattern could be formed by etching with a source gas Cl ₂ (40 SCCM), a vacuum degree of 40 mTorr, and an excitation power of 100 W using the apparatus.

Using this polysilane pattern as a mask and using a magnetron type RIE device, source gas CHF ₃ (40 SCCM), CO (155 SCCM),
O ₂ (10 SCCM), excitation power 800 W, vacuum degree 40
Etching was performed under the condition of mTorr. as a result,
An oxide film pattern having a thickness of 0.15 μm was formed, and the cross section of the obtained oxide film pattern was rectangular, and the side wall thereof was also vertical and had a good shape.

(Comparative Example 4) A 0.5 μm thick SOG oxide film was formed as a layer to be processed on a silicon wafer.

A KrF excimer laser resist is coated on this and baked at 100 ° C. for 1 minute to form a film having a thickness of 0.5.
A μm resist film was formed. For this resist film,
100 KrF excimer laser through a specified mask
After exposure with an exposure amount of mJ / cm ^2, the film was baked at 130 ° C. for 1 minute.

Subsequently, when a resist pattern was formed by developing with a 2.38% tetramethylammonium hydroxide aqueous solution, a standing wave was confirmed on the side wall of the obtained pattern.

[0253]

As described above, according to the present invention, there is provided a photosensitive composition capable of forming a resist pattern with good dimensional accuracy, which is preferably used for patterning a layer to be processed. By using the present invention, it is possible to process a semiconductor wafer or a layer to be processed formed on the wafer with high dimensional accuracy, and its industrial value is enormous.

[Brief description of drawings]

FIG. 1 is a process sectional view showing an example of a first pattern forming method of the present invention.

FIG. 2 is a process sectional view showing an example of a second pattern forming method of the present invention.

FIG. 3 is a process sectional view illustrating an example of a third pattern forming method of the present invention.

FIG. 4 is a process sectional view showing an example of a third pattern forming method of the present invention.

FIG. 5 is a process cross-sectional view showing an example of a fourth pattern forming method of the present invention.

FIG. 6 is a process sectional view illustrating an example of a fifth pattern forming method of the present invention.

FIG. 7 is a process sectional view illustrating an example of a fifth pattern forming method of the present invention.

FIG. 8 is a process cross-sectional view showing an example of a pattern forming method using the photosensitive composition of the present invention.

[Explanation of symbols]

1 ... Substrate 2 ... Layer to be processed 3 ... Organosilicon film 3a ... Si-O-Si bond region 3b ... Si-Si bond region 3c ... Si-C-Si bond region 3d ... Si-O-Si bond region 4 ... Exposure light 5 ... Metal film 6 ... Resist film 6a ... Siloxane-based pattern 7 ... Si-O containing film 11 ... Organosilicon film 11a ... Siloxane-based pattern

─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Sawako Yoshikawa 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center, Inc. (72) Inventor Yasuhiko Sato 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa (56) Reference JP-A-8-305028 (JP, A) JP-A-64-56732 (JP, A) JP-A-63-38933 (JP, A) JP-A-9-208704 (JP, A) JP-A-8-262728 (JP, A) JP-A-7-114188 (JP, A) JP-A-10-268521 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) G03F 7/00-7/42

Claims (2)

(57) [Claims] 1. Repetition represented by the following general formula (2):
A silicon compound having a unit and an acid by irradiation with light
A photosensitive composition containing a generating compound. [Chemical 1] (In the general formula (2), P is an acid represented by the following general formula.
It reacts with and decomposes to form carboxyl groups
Is a group that is solubilized in an alkaline aqueous solution, and Z is a hydrogen source.
Child, substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms,
Indicates an aromatic hydrocarbon group. ) [Chemical 2] 2. Introduced as Z in the general formula (2).
The hydrocarbon group is a group represented by the following chemical formula
Photosensitivity according to claim 1, characterized in that it is selected from
Composition. [Chemical 3]