JP2000298350A - Photoresist composition containing cyclic olefin polymer and additive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photoresist composition using an acid as a catalyst, capable of forming an image with radiation of 193 nm and capable of forming a photoresist structure having high resolution and high etching resistance by development. SOLUTION: The photoresist composition comprises a combination of a cyclic olefin polymer, a photosensitive acid-generating agent and a substantially transparent bulky hydrophobic additive. The cyclic olefin polymer contains a cyclic olefin unit having a polar functional group which promotes dissolution in an aqueous alkali solution and the cyclic olefin unit having an acid-labile group which inhibits the dissolution in the aqueous alkali solution. The hydrophobic additive is selected from the group comprising a saturated steroid compound, a non-steroid cycloaliphatic compound and a non-steroid polycycloaliphatic compound having an acid-labile bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist composition capable of forming a high-resolution pattern adapted to short-wavelength radiation, and a method for forming a pattern using such a resist composition.

[0002]

BACKGROUND OF THE INVENTION In the microelectronics industry and other industries related to the fabrication of microstructures (e.g., micromachines, magnetoresistive heads, etc.), there is a continuing need to reduce the size of structural features. In the microelectronics industry, this need is to reduce the size of microelectronic devices and / or increase the amount of circuitry mounted on a chip of a given size.

[0003] The ability to reduce the size of devices is limited by the ability of photolithography techniques to reliably resolve reduced features and gaps. A property of optical devices is that the ability to increase resolution is limited, in part, by the wavelength of light (or other radiation) used to generate the lithographic pattern. Therefore, there is a continuing tendency to shorten the wavelength of light used for photolithography. Recently, this trend has become so-called I-line radiation (350n
m) to 248 nm radiation.

[0004] For future miniaturization, perhaps 193
It is believed to use nm radiation. Unfortunately, the photoresist compositions at the heart of current photolithographic processes using 248 nm radiation are typically
It is not suitable for use at shorter wavelengths.

[0005] While the photoresist composition must have the desired optical properties that can be resolved at the wavelength of the desired radiation, the photoresist composition also has a patterned image. It must have chemical and mechanical properties suitable for transfer from a photoresist to an underlying substrate layer. Therefore, a positive photoresist that has been exposed according to the pattern must be capable of adequate resolution response (ie, selective resolution of the exposed areas) in order to obtain the desired photoresist structure. It is important to perform extensive experimentation with photolithographic techniques using aqueous alkaline developers to achieve adequate resolution with such commonly used developer solutions.

The patterned photoresist structure (after development) must withstand transfer of the pattern to the underlying layer. Generally, the transfer of the pattern is effected by some type of wet chemical or ion etching.
The ability of a patterned photoresist layer to withstand a pattern transfer etching process (ie, the etch resistance of the photoresist layer) is an important property of the photoresist composition.

[0007] Although some photoresist compositions have been designed for use with 193 nm radiation, these compositions generally lack performance in one or more of the above-mentioned regions, and therefore have a short duration. It does not provide true resolution benefits for imaging at wavelengths. Therefore, short wavelength radiation (eg, 250 nm) with good developability and etch resistance
There is a need for photoresist compositions that can be imaged using shorter, more preferably shorter than 200 nm, most preferably 193 nm ultraviolet light).

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photoresist which has good developability and pattern transfer characteristics and which can produce high resolution photolithographic patterns using short wavelength radiation. It is to provide a composition.

[0009]

SUMMARY OF THE INVENTION The present invention provides a photoresist composition having high resolution lithographic performance using short wavelength, eg, 193 nm, imaging radiation. The photoresist compositions of the invention have the combination of very high resolution, imaging ability, developability, and etch resistance required for pattern transfer, limited only by the wavelength of the imaging radiation. Photoresist compositions of the present invention are generally characterized by the presence of a cycloolefin polymer having a combination of acid labile functional groups and acidic polar functional groups. The photoresist composition of the present invention is preferably further characterized by the presence of a bulky hydrophobic additive that is substantially transparent to the wavelength of the imaging radiation, such as 193 nm.

The present invention also provides a method for forming a photoresist structure using the photoresist composition of the present invention,
Also provided is a method for transferring a pattern to a lower layer using the photoresist structure. The photolithographic method of the present invention is characterized by the use of pattern-wise exposure to short wavelength, most preferably 193 nm, ultraviolet radiation. The method of the present invention preferably includes features having dimensions less than about 150 nm, without using a phase shift mask,
More preferably, the dimensions are less than about 120 nm or less than about 115 nm (using an optical system with a numerical aperture of 0.68).
Of features can be resolved.

In one aspect, the present invention provides: (a) i) a cyclic olefin unit having an acidic or non-acidic polar functional group that promotes solubility in an aqueous alkaline solution; and ii) an aqueous alkaline solution. A cyclic olefin polymer having a cyclic olefin unit having an acid-labile group that inhibits solubility in (b) a photosensitive component; and (c) substantially transparent to ultraviolet radiation. A photoresist composition having a bulky hydrophobic additive component.

The cyclic olefin polymers according to the invention preferably contain about 5 to 40 mol% of unit i). The cyclic olefin polymer of the present invention is preferably mainly composed of cyclic olefin monomer units, more preferably mainly composed of unit i).
And unit ii). The bulky hydrophobic additives preferably contain alicyclic groups. Preferred hydrophobic additives are those selected from the group consisting of saturated steroid compounds, non-steroid alicyclic compounds, and non-steroid poly-alicyclic compounds having a plurality of acid labile bonds.

The cyclic olefin polymer of the present invention preferably comprises mainly cyclic olefin monomer units, and more preferably mainly comprises units i) and ii).
Unit i) preferably contains an acidic polar group with pK _a ≦ 13. Hydrophobic non-steroidal alicyclic component, preferably those containing C ₁₀ to or higher alicyclic group. Also,
The HNMP component of the present invention preferably contains a C ₇ or higher alicyclic group, and a compound having a plurality of acidic polar groups or at least one compound each having a plurality of acidic polar groups by the cleavage of HNMP with an acid. It is preferable to produce any one of a plurality of compounds having an acidic polar group, or both compounds.

In another aspect, the invention includes a method of forming a patterned photoresist structure on a substrate. The method includes the steps of (a) forming a substrate having a surface layer of the photoresist composition of the present invention, and (b) exposing the photoresist layer to radiation according to a pattern, thereby radiating a portion of the photoresist layer. (C) contacting the photoresist layer with an aqueous alkaline developer to remove the exposed portion of the photoresist layer;
Forming a patterned photoresist structure. Most preferably, the radiation used in step (b) of the method is 193 nm ultraviolet radiation.

The present invention also encompasses a process for making a conductive, semiconductive, magnetic or insulating structure utilizing a patterned photoresist structure containing the composition of the present invention.

[0016] These and other aspects of the invention are described in further detail below.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The photoresist compositions of the present invention generally comprise i) a cyclic olefin unit having an acidic polar functional group that promotes solubility in aqueous alkaline solutions;
It is characterized by the presence of a polymer containing a cyclic olefin unit having an acid-labile group that suppresses solubility in an aqueous alkali solution. This cyclic olefin polymer preferably has a cyclic olefin unit i) content of 40 mol% or less. The composition is further characterized by the presence of a bulky hydrophobic additive that is substantially transparent to the wavelength of the imaging radiation. These compositions have good developability and pattern transfer properties and are capable of producing high resolution photolithographic patterns using short wavelength, eg, 193 nm, radiation.

The present invention further provides a patterned photoresist structure containing the photoresist composition of the present invention, a method of making such a photoresist structure, and the use of this photoresist structure to provide conductive, semiconductive sex,
And a method of forming all or any of the insulating structures.

The photoresist compositions of the present invention generally comprise: (a) i) a cyclic olefin unit having an acidic polar functional group that promotes solubility in an aqueous alkaline solution; and ii) a solubility inhibitor in an aqueous alkaline solution. A cyclic olefin polymer having a cyclic olefin unit having an acid labile group, (b) a photosensitive component, and (c) a bulky additive component that is substantially transparent to ultraviolet radiation. Having.

The cyclic olefin unit i) used in the resist composition of the present invention may be any cyclic olefin monomer unit having an acidic polar group or a non-acidic polar group which promotes solubility in an aqueous alkaline solution. It may be. Examples of the cyclic olefin monomer include the following monomers represented by the structure (I), wherein R ₁ is a polar group, and n is 0 or a positive integer.

Embedded image

More preferably, the cyclic olefin unit i) is selected from a) and b) below.

Embedded image In the formula, R ₁ is an acidic polar group or a non-acidic polar group that promotes solubility in an aqueous alkaline solution. The acidic polar group is preferably _a pK _a of about 13 or less. Preferred acidic polar groups include a polar group selected from the group consisting of a carboxyl group, a sulfonamidyl group, a fluoroalcohol group, and other acidic polar groups. Preferred acidic polar groups are carboxyl groups. On the other hand, preferred non-acidic polar groups have a pKa greater than about 13 and at least one
Contains heteroatoms such as oxygen, nitrogen or sulfur. If desired, combinations of cyclic olefin units i) with different polar functional groups can also be used. Preferably,
At least some or all of the cyclic olefin units i) are acidic polar functional groups.

The cyclic olefin unit ii) may be any cyclic olefin monomer unit having an acid-labile group which suppresses the solubility in an aqueous alkaline solution. Examples of cyclic olefin monomers include the following monomers of structure (III) wherein R ₂ is an acid-labile protecting group, n
Is 0 or a positive integer.

Embedded image

More preferably, the cyclic olefin unit i
i) is selected from the following a) and b).

Embedded image In the formula, R ₂ represents an acid-labile protecting group. Preferred acid labile protecting groups are those selected from the group consisting of tertiary alkyl (or cycloalkyl) carboxyl esters (eg, t-butyl, methylcyclopentyl, methylcyclohexyl, methyladamantyl), ester ketals, and ester acetals. It is. Tertiary butyl carboxyl ester is the most preferred acid labile protecting group. If necessary, combinations of cyclic olefin units ii) with different protective functions can also be used.

For photolithographic applications used in the manufacture of integrated circuit structures and other microstructures, the cyclic olefin polymers of the present invention may contain from about 5 to 80 mole percent, preferably from about 10 to about 60 mole percent, of a cyclic olefin polymer. Those containing olefin units i) are preferred. When the cyclic olefin unit i) consists predominantly of carboxylic acid functionalized units, the cyclic olefin polymer of the present invention is preferably about 5-30 mol%, more preferably about 10-25 mol%, most preferably About 1
It contains 0 to 20 mol% of cyclic olefin units i).
When the cyclic olefin units i) consist of units having a sulfonamidyl acidic polar group, these units are preferably present in an amount of about 15 to about the entire cyclic olefin polymer composition.
５０50 mol%, more preferably about 20-40 mol%. When the cyclic olefin unit i) consists predominantly of other acidic functionalized units, the cyclic olefin polymer of the present invention is more preferably about 10-80 mol%, most preferably about 20-40 mol% of ring olefin polymer. It contains the formula olefin unit i). The cyclic olefin polymer of the present invention comprises at least about 20 mole%, preferably at least about 30 mole%,
More preferably about 40 to 90 mole%, most preferably about 60 to about 90 mole% of cyclic olefin units ii)
It contains. When a carboxylic acid is used as an acidic group,
When about 80-90 mol% of other acidic functionalized units are used, it preferably contains about 60-80 mol% of cyclic olefin units ii). The cyclic olefin polymer of the present invention may contain other monomer units in addition to the units i) and ii). Preferably, the cyclic olefin polymer of the present invention contains such other monomer units in an amount of about 40 mol% or less, more preferably about 20 mol% or less.
Mol% or less. More preferably, the cyclic olefin polymer of the present invention comprises substantially units i) and ii).
It consists only of

The photoresist composition of the present invention contains a photosensitive acid generator (PAG) as a photosensitive component in addition to the cyclic olefin polymer. The present invention relates to any particular P
It is not limited to using a combination of AG or PAG, that is, the advantages of the present invention can be achieved using various photosensitive acid generators well known to those skilled in the art. Preferred PAGs are those that contain only small amounts (preferably no) of aryl groups. PA containing an aryl group
If G is used, the wavelength of the imaging radiation (eg, 193n)
The absorption properties of the PAG in m) limit the amount of PAG contained in the formulation.

Examples of suitable photosensitive acid generators include onium salts such as triarylsulfonium hexafluoroantimonate and diaryliodonium hexafluoroantimonate, hexafluoroarsenates, triflates, perfluoroalkane sulfonates ( Substituted aryl sulphonates such as, for example, perfluoromethane sulphonate, perfluorobutane sulphonate, perfluorohexane sulphonate, perfluorooctane sulphonate, etc., pyrogallols (for example pyrogallol trimesylate or pyrogallol trissulphonate) , Sulfonic acid esters of hydroxyimide, N-sulfonyloxynaphthalimides (N-camphorsulfonyloxynaphthalimide, N-pentafluorobenzenesulfonyloxynaphthalimidine) ), Alpha,. Alpha .'- bis-sulfonyl diazomethane, naphthoquinone-4-diazides, alkyl disulfonates, other is (but that none of the aryl group shown is alkyl substituted are preferred).

The photoresist composition of the present invention further comprises:
A bulky hydrophobic additive ("BH") that is substantially transparent to the wavelength of the imaging radiation (eg, 193 nm).
Additive) is present. BH additives can generally react with conventional aqueous alkaline developers to resolve ultra-fine lithographic features or enhance resolution. Preferably, the BH additive has the characteristic that at least one alicyclic group is present. Preferably, the BH additive contains at least 10 carbon atoms, more preferably contains at least 14 carbon atoms, and most preferably contains 14 to 60 carbon atoms. The BH additive further decomposes in the presence of one or more acids to produce an acid-labile component that acts to enhance the solubility of the radiation-exposed portions of the photoresist in aqueous alkaline solutions. Those containing a group such as a pendant group are preferred. Preferred BH additives are saturated steroids (“S
S ") compounds, non-steroidal alicyclic (" HNA ") compounds, and non-steroidal polyalicyclic (" HNM ") compounds having an acid labile linking group between at least two alicyclic groups.
P ") selected from the group consisting of compounds. More preferred BH additives include tert-butyl-3-trifluoroacetyl lithocholic acid, tert-butyladamantane carboxylate, and bisadamantyl carboxylate.
There are lithocholic acid salts such as t-butyl. If necessary, two or more BH additives can be used in combination.

The saturated steroid ("SS") component suitable for the photoresist compositions of the present invention generally reacts with conventional aqueous alkaline developers to resolve or resolve ultra-fine lithographic features. Ability to be enhanced. The SS component is characterized by the presence of at least one saturated steroid (C ₁₇ ) alicyclic skeletal structure.
The saturated steroid component may be composed of a compound having a plurality of saturated steroid groups (for example, a bissteroid or a trissteroid). Preferably, S
The S component is a group consisting of an acid-labile group (for example, a group that reacts with an acid generated during a photolithography step, thereby cleaving the group to form a molecule that promotes solubility in an aqueous alkaline solution). It contains one or more pendant groups selected from: Preferred SS components may further contain a pendant group such as a group selected from the group consisting of a formyl group, a hydroxyl group, and a trifluoroacetyl group. If one or more acid-labile pendant groups are present, they can be separated by one or more spacer groups, such as the structures SL-1 and SL-2 shown below. Generally, highly hydrophobic SS components are preferred. If necessary, a plurality of SS components may be used in combination.

Examples of preferred SS components include cholic acid esters (eg, t-butyl lithocholic acid, t-butyl deoxycholate, t-butyl cholic acid), ester-modified lithocholic acid esters (eg, lithocholic acid-
t-butyl-3-trifluoroacetyl, t-butyl 3-acetyllithocholic acid, t-butyl lithocholic acid-3-pivalyl), ester-modified cholic acid esters (for example, t-butyl-3,7, cholic acid) 12-triformyl, t-butyl-cholate-tris (3,7,12-
Trifluoroacetyl)) and the structure SL shown below
There are lithocholic esters having spacer groups such as -1 and SL-2.

Embedded image

Embedded image Wherein tBu is a tertiary butyl group. Most preferred SS
The component is t-butyl-3-trifluoroacetyl lithocholic acid.

[0030] The sparsely suitable photographic resist composition of the present invention.
The aqueous non-steroidal cycloaliphatic ("HNA") component generally comprises
Reacts with conventional alkaline aqueous solution developer
Resolve graphics features or enhance resolution
can do. This HNA component is a non-steroidal fat
Cyclic structures (ie, C, a characteristic of steroid compounds) ₁₇
Which does not contain a condensed cyclic structure)
And The alicyclic structure has at least 6 carbon atoms
Containing (C₆) Is preferred, and at least 10
And more preferably those containing 10 to 3 carbon atoms.
Those containing zero carbon atoms are most preferred. HNA
The additive as a whole has at least about 14 carbon atoms.
Those containing from about 14 to 50 carbon atoms.
Those containing are more preferred. If necessary, the invention
HNA additives contain one or more cycloaliphatic groups
May be used. This composition comprises two alicyclic groups
If present, they must be separated by acid-labile linking groups.
Is preferred. Such a polyalicyclic compound has the following formula:
(V).

Embedded image

Preferably, the HNA component is pendant to one or more acid-labile pendant groups (eg, reacts with an acid generated in a photolithography step, thereby cleaving the group and promoting solubility in aqueous alkaline solutions). Group that acts). Preferred acid labile groups are tertiary alkyl (or cycloalkyl) carboxylic esters,
(For example, t-butyl, methylcyclopentyl, methylcyclohexyl, methyladamantyl), ester ketal, and ester acetal. The HNA component may also contain pendant groups that enhance the bulk of the molecule and / or increase the hydrophobicity of the molecule to enhance the properties of the photoresist composition. One or more acid labile pendant groups can be separated from the cycloaliphatic group by one or more spacer groups. If necessary, HNA components may be used in combination.

Examples of preferred HNA components include carboxylic esters of adamantane, and higher fused alicyclic structures. The most preferred HNA component is adamantane t-butyl carboxylate.

Some examples of HNA components have the structures shown below.

Embedded image

Embedded image

Embedded image

Embedded image

[0034] Hydrophobic non-steroidal polyalicyclic moieties containing an acid-labile linking group ("HNMP") suitable for the photoresist compositions of the present invention also generally react with conventional aqueous alkaline developers. To resolve or enhance resolution capabilities of ultra-small lithographic features. The HNMP component is characterized by the presence of at least two distinct non-steroidal alicyclic structures (ie, structures that do not contain the C ₁₇ fused ring structure characteristic of steroid compounds). The alicyclic structure preferably has at least 7 carbon atoms excluding the pendant group (C ₇ ), and more preferably has about 10 to 30 carbon atoms. Preferably, the overall HNMP component contains about 20 to 60 carbon atoms.

In general, the HNMP component comprises at least two acid labile linking groups and at least two alicyclic groups, with an acid labile bond between at least two alicyclic groups. Include compounds that are present as present.

This HNMP compound contains a plurality of acid-labile bonding groups and a plurality of alicyclic groups. One structure of such a compound is represented by the following formula.

Embedded image

The bond between R and X is such that at least one X _c -R ′ (X _c is an acidic polar pendant group from R ′) derivative is formed by acid cleavage of the R—X bond. ,
It is an acid-labile bond. In the above formula, n is at least 2. When R contains an alicyclic group, at least one R 'is an alicyclic group. When R does not contain an alicyclic group, at least two R's are each an alicyclic group.
When X is a carboxyl group, the structure is as follows:

Embedded image In the formula, the bond between R and O is an acid-labile bond. After cleavage, the carboxylic acid group remains a pendant group on R '. When n is 2 and R 'is an adamantane group, the structure is as follows.

Embedded image Wherein R is a combination of an acid labile ester group, such as two t-butyl ester groups attached, (structure VIIa below, wherein 1 indicates the site of the acid labile bond) or other acid Unstable bond. Cleavage results in a plurality of compounds containing an R ′ group along with a pendant carboxylic acid group.

Embedded image

Alternatively, the HNMP compound may have the following structure:

Embedded image Wherein the bond between R ′ and X ′ is R- (X _c ) _{n ′} (where X _c is R
Is an acid-labile bond, such that an acidic polar pendant group derivative is formed by cleavage of the R'-X 'bond with an acid. In the above formula, n ′ is at least 2. At least one R ′ alicyclic group, and the total of at least one R or remaining R ′ group consists of an acryl group. The result after cleavage is in each case the formation of two smaller molecules, each containing an alicyclic group, and the formation of a plurality of polar functional groups pendent from R.

When X is a carboxyl group, the structure is as follows:

Embedded image After cleavage, R contains multiple (n ') carboxylic acid pendant groups. Wherein R is a norbornyl alicyclic group,
n ′ = 2, each R ′ contains adamantane, and the HNMP additive has the following structure:

Embedded image After cleavage, the norbornyl compound has two pendant carboxylic acid groups.

[0040] Other possible HNMP additive structures include:

Embedded image

Embedded image

In the HNMPs used in the present invention, the acid labile linking group reacts favorably with the acid formed during the photolithography step, thereby cleaving the group to form multiple molecules or reduce the molecular weight. Substantially reduce or enhance the solubility of the exposed portions of the photoresist in aqueous alkaline solutions. Preferred acid labile linking groups are selected from the group consisting of tertiary alkyl (or cycloalkyl) carboxylate esters (eg, t-butyl, methylcyclopentyl, methylcyclohexyl, methyladamantyl), ester ketals, and ester acetals. It is a thing. The HNMP component may also contain pendant groups that enhance the bulk of the molecule and / or increase the hydrophobicity of the molecule to enhance the properties of the photoresist composition. If necessary, HNMP components may be used in combination.

Examples of preferred HNMP components include the biscarboxyl esters of adamantane and higher fused cycloaliphatic ring structures. The most preferred HNMP component is bis-adamantane t-butyl carboxylate.

The photoresist compositions of the present invention usually contain a solvent before being applied to the intended substrate. The solvent can be any solvent conventionally used in acid catalyzed photoresists without unduly adversely affecting the performance of the photoresist composition. Preferred solvents are propylene glycol monomethyl ether acetate, cyclohexane, and ethyl cellosolve acetate.

The compositions of the present invention further contain auxiliary ingredients well known to those skilled in the art, such as small amounts of dyes / sensitizers, base additives, and the like. Preferred base additives are weak bases that trap trace amounts of acid and do not unduly adversely affect photoresist performance. Preferred base additives include tertiary alkylamines (aliphatic or aromatic) or tert-alkylammonium hydroxide such as tert-butylammonium hydroxide (TBAH).

The photoresist composition of the present invention preferably comprises about 0.5 to 20% by weight, more preferably about 3 to 1% by weight, based on the total weight of the cyclic olefin polymer in the composition.
5% by weight) of a photosensitive acid generator. If a solvent is present, it is preferred that the entire composition contain about 50-90% by weight of the solvent. The composition preferably comprises about 1% by weight, based on the total weight of the acid-sensitive compounds.
It contains the following base additives. The photoresist composition of the present invention preferably comprises at least about 5% by weight, more preferably 10-25% by weight, and most preferably about 10% by weight, based on the total weight of the cyclic olefin polymer in the composition.
-20% by weight of the BH additive component, or the HNA additive component, the HNMP additive component, or the SS additive component.

The present invention is not limited to any particular method for synthesizing the cyclic olefin polymer used in the present invention. Preferably, the cyclic olefin polymer is formed by addition polymerization. Examples of suitable techniques are described in F. U.S. Pat. No. 5,468,881 assigned to BF Goodrich Company and incorporated herein by reference.
Nos. 9 and 5705503.

The cyclic olefin polymer of the present invention preferably has a weight average molecular weight of about 5,000 to 100,000, more preferably about 10,000 to 50,000.

The photoresist composition of the present invention comprises a cyclic olefin polymer, a PAG, a BH additive component, or HN.
The A, HNMP, or SS component and other desired components can be produced by combining using conventional methods. Photoresist compositions used in photolithographic methods generally contain significant amounts of solvents.

The photoresist compositions of the present invention are particularly useful in photolithographic methods used to manufacture integrated circuits on semiconductor substrates. This composition is particularly useful in photolithographic methods that utilize 193 nm ultraviolet radiation. Other radiation (eg, medium wavelength ultraviolet, 248 nm
If necessary, the composition of the present invention can be adjusted by adding a suitable dye or sensitizer (if necessary) to the composition. Can be. The method of using the photoresist composition of the present invention for photolithography for semiconductors is described below.

Photolithographic applications for semiconductors usually involve the transfer of a pattern to a layer of material on a semiconductor substrate. The layers of material on the semiconductor substrate are used during the manufacturing process,
And depending on the intended material set for the final product, it may be a conductive layer of metal, an insulating layer of ceramic, a semiconductor layer, or other material. In many instances, anti-reflective coatings (A
RC) is applied to the material layer before applying the photoresist layer. The ARC layer can be any conventional ARC that is compatible with the acid catalyzed photoresist.

Typically, a photoresist composition containing a solvent is applied to the intended semiconductor substrate using spin coating or other techniques. Next, the substrate coated with the photoresist coating is preferably heated (baked before exposure) to remove the solvent and improve the adhesion of the photoresist layer. The thickness of the applied layer is preferably substantially uniform, provided that the photoresist layer is sufficiently resistant to the process of transferring the subsequent lithographic pattern to the underlying substrate material layer (usually reactive ion etching). Is preferably as thin as possible. The pre-exposure baking step is preferably performed for about 10 seconds to about 15 minutes, and more preferably for about 15 seconds to about 1 minute. The pre-exposure baking temperature can be varied depending on the glass transition temperature of the photoresist. Preferably, the pre-exposure bake is performed at a temperature at least 20 ° C. below T _g .

After removing the solvent, the photoresist layer is exposed according to the pattern to the desired radiation (for example 193 nm UV radiation). When using a scanning particle beam such as an electron beam, patternwise exposure can be accomplished by scanning a light beam across the substrate and selectively providing the light beam in a desired pattern. More typically, when the wavy radiation forms 193 nm ultraviolet radiation, or the like,
Exposure according to the pattern is performed through a mask placed on the photoresist layer. For ultraviolet radiation at 193 nm, the total exposure energy is preferably about 100 millijoules / c
m ² or less, more preferably about 50 mJ / cm ²
(15-30 mJ / cm ² ).

After performing exposure according to the intended pattern,
The photoresist layer is typically baked to allow the acid catalyzed reaction to proceed more completely and increase the contrast of the exposed pattern. Baking after exposure is preferably about 100 to 175 ° C, more preferably about 125 to 16 ° C.
Perform at 0 ° C. Baking after exposure is from about 30 seconds to about 5 seconds.
It is preferable to carry out for minutes.

After the post-exposure baking, the photoresist layer is brought into contact with an alkaline solution that selectively dissolves the exposed portion of the photoresist by radiation,
A photoresist structure having the desired pattern is obtained (developed). Preferred alkaline solution (developer) is
It is an aqueous solution of tetramethylammonium hydroxide. Preferably, the photoresist composition of the present invention can be developed with a conventionally used 0.26N aqueous alkaline solution. The photoresist composition of the present invention also includes
Development with 0.14N, 0.21N, or other concentrations of aqueous alkaline solutions is also possible. Next, the photoresist structure obtained on the substrate is usually dried to remove the remaining developer. The photoresist composition of the present invention generally comprises
The obtained photoresist structure has a feature of having high etching resistance. In certain instances, post-silylation techniques well known to those skilled in the art can be used to enhance the etch resistance of the photoresist structure. The compositions of the present invention allow for the reproduction of lithographic features.

The pattern from the photoresist structure can then be transferred to the underlying substrate material (eg, ceramic, metal, or semiconductor). Typically, the transfer is performed by reactive ion etching or some other etching technique. In reactive ion etching, the etch resistance of the photoresist layer is important. Thus, the compositions of the present invention, and the resulting photoresist structures, can be used to design metal interconnects, contact holes or vias, insulators (e.g., damascene trenches or shallow trenches) as used in integrated circuit device design. ), And can be used for forming a patterned material layer structure such as a trench having a capacitor structure.

The method of forming these (ceramic, metal, or semiconductor) features typically includes providing a layer or portion of a substrate material to be patterned;
Applying a layer of photoresist over the layer or portion of the material, exposing the photoresist to radiation according to a pattern, and contacting the exposed photoresist with a solvent to develop the pattern; Forming a layer or portion of the patterned material or substrate portion by etching one or more layers below the photoresist layer in the space of the pattern, and removing any residual photoresist from the substrate Performing the steps. In one example, a hard mask is used below the photoresist layer to facilitate transfer of the pattern to an underlying material layer or portion. An example of such a method is described in US Pat. No. 4,855,017.
No. 5,362,663, No. 5,429,710, No. 55
No. 62801, No. 5618751, No. 5744376
Nos. 5,801,094 and 5,821,469, which are hereby incorporated by reference. Examples of other methods of transferring patterns are described in Wayne Moresu, Semiconductor Lithography, Principles, Practice, and Materials.
Lithography, Principles, Practices, and Material
s) ", Plenum Press, 1988
Years, Chapters 12 and 13, the disclosure of which is hereby incorporated by reference. It should be understood that the invention is not limited to any particular lithographic technique or device structure.

[0057]

EXPERIMENTAL EXAMPLE 1 (Comparative Example) For the purpose of conducting a lithography experiment, norbornene-t-
85% of butyl ester (NB-t-BE) and (as a pendant group) norbornene carboxylic acid (NB-CA) 1
A photoresist formulation containing a norbornene copolymer containing 5% was prepared by blending the materials shown in parts by weight below.

[Table 1]

This photoresist formulation was applied to a silicon
Antireflective material coated on the wafer was spin-coated (30 seconds) and on the (ArX ^(R), Shipley Company (Shipley Company)) layer. This photoresist layer was soft baked on a vacuum hot plate at 130 ° C. for 60 seconds to form a film having a thickness of about 0.4 μm. Next, the wafer was irradiated at 193 nm (0.6 NA).
(ArF, ISI stepper). The exposure pattern was an array of lines with a minimum spacing of at least 0.1 μm in size. The exposed wafer was baked on a vacuum hot plate at 150 ° C. for 90 seconds. Next, the photoresist that has been subjected to pattern exposure is
Developed (paddle) with 3N tetramethylammonium hydroxide developer. Next, the pattern was scanned using a scanning electron microscope (SE).
M). According to the cross-sectional SEM pattern, it was found that L / S (line / interval pair) less than 200 nm was not resolved because the lines overlapped each other. Even line-spacing pairs greater than 200 nm were not completely resolved due to excessive debris / residue between the lines.

Experimental Example 2 Synthesis of t-butyl-3-trifluoroacetyl lithocholic acid A 12-liter four-necked round bottom equipped with a top stirrer, a thermocouple temperature monitor, and a constant-pressure dropping funnel with a nitrogen inlet. The flask was charged with 500 g (1.328 mol) of lithocholic acid and 4 liters of dry THF. Next, 1920 ml (13.6 mol) of trifluoroacetic anhydride was put into the dropping funnel. The flask was cooled with ice under a nitrogen atmosphere and the trifluoroacetic anhydride was added in a small stream while keeping the temperature below 10 ° C. After the mixture was allowed to warm to room temperature with stirring overnight, the solvent and excess trifluoroacetic anhydride were removed on a rotary evaporator. The thick viscous intermediate was returned to the 12 liter flask and an additional 4 liters of THF was added. The dropping funnel was charged with 740 g (10 mol) of t-butyl alcohol (diluted with a small amount of THF to prevent solidification). The flask was cooled again with ice, keeping the temperature below 10 ° C.
-Butyl alcohol was added in a small stream. The mixture was allowed to return to room temperature overnight. Next, solid NaHCO ₃
About 200 g were added and stirring was continued for another 2 hours. Next, the solvent and excess t-
The butyl alcohol was removed, the mixture was dissolved in 4 liters of ethyl ether, and then carefully washed three times with 800 ml of a saturated solution of NaHCO ₃ and then washed with 1000 ml of water.
Washed twice. The solvent was dried for 1 hour with stirring over MgSO ₄ , filtered and evaporated on a rotary evaporator. The thick viscous residue was slowly eluted with hexane on a large column containing 800 g of silica gel in hexane. The product fractions were combined and evaporated on a rotary evaporator, and the remaining solvent was removed under reduced pressure at 40 ° C. in a stream of nitrogen until quantified, yielding 620 g (88% yield) of the expected product. Obtained as an off-white syrupy liquid. The product was crystallized from pentane at -78 ° C to give a low melting white wax.

Example 3 This example illustrates the advantage of the composition of the present invention containing a saturated steroid additive. A photoresist formulation was prepared by compounding the materials shown in parts by weight below.

[Table 2]

The photoresist formulation was applied to a silicon
Antireflective material coated on the wafer was spin coated onto the (ArX ^(R), Shipley Company (Shipley Company)) layer was exposed according to a pattern (193 n
m), and developed in the same manner as in Experimental Example 1. Next, the obtained pattern was inspected with a scanning electron microscope (SEM). Line / spacing pairs of 140 nm or more were well resolved and a clear profile was obtained. The exposure energy required for this formulation was in the range of 25-35 mJ / cm ² .

Experimental Example 4 Synthesis of adamantane-1-carboxylic acid-t-butyl ester t-butyl alcohol 2 in 600 ml of methylene chloride
In a suspension in which 5.34 g (0.342 mol) is suspended,
At room temperature, 38.07 g (0.3815 mol) of triethylamine were added. The resulting suspension was stirred at room temperature until a clear solution. To the solution at 0 ° C. was added 74.75 g (0.3762 mol) of adamantane-1-carbonyl chloride. After the addition was complete, the reaction mixture was stirred at room temperature for 12 hours and then at reflux for 2 hours. The reaction mixture was filtered to remove triethylamine hydrochloride generated during the reaction. The filtrate was washed several times with water (× 500 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane / methylene chloride 9: 1).
4 g (-60%) of a white solid was obtained. This solid is
NMR spectroscopy identified adamantane-1-carboxylic acid-t-butyl ester.

Experimental Example 5 This experimental example illustrates the advantage of the composition of the present invention containing adamantane-1-carboxylic acid-t-butyl ester. A photoresist formulation was prepared by compounding the materials shown in parts by weight below.

[Table 3]

This photoresist formulation was treated with silicon
Antireflective material coated on the wafer was spin coated onto the (ArX ^(R), Shipley Company (Shipley Company)) layer was exposed according to a pattern (193 n
m), and developed in the same manner as in Experimental Example 1. Next, the obtained pattern was inspected with a scanning electron microscope (SEM). Line / spacing pairs of 140 nm or more were well resolved and a clear profile was obtained. Exposure energy required for this formulation was in the range of 20~30mJ / cm ^2.

EXPERIMENTAL EXAMPLE 6 Synthesis of 2,5-bis (adamantane-1-carboxyloxy) -2,5-dimethylhexane 2,6-dimethyl-2,5 in 600 ml of methylene chloride
76.14 g of triethylamine was added to a suspension of 50 g (0.342 mol) of hexanediol at room temperature.
(0.762 mol) was added. The resulting suspension was stirred at room temperature until a clear solution. 0 ° C in the solution
Adamantane-1-carbonyl chloride in 149.5 g
(0.7524 mol) was added. After the addition is complete,
The reaction mixture was stirred at room temperature for 12 hours and then refluxed for 2 hours.
Stirred for hours. The reaction mixture was filtered to remove triethylamine hydrochloride generated during the reaction. Filter the filtrate with water (× 50
0 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane / methylene chloride 9: 1) to give 128 g (〜80%) of a white solid. This solid was analyzed by NMR spectroscopy for 2,5-bis (adamantane-1-carboxoxy) -2,5.
-Dimethylhexane.

Experimental Example 7 This experimental example illustrates the advantages of the composition of the present invention containing 2,5-bis (adamantane-1-carboxoxy) -2,5-dimethylhexane. A photoresist formulation was prepared by compounding the materials shown in parts by weight below.

[Table 4]

This photoresist formulation was treated with silicon
Antireflective material coated on the wafer was spin coated onto the (ArX ^(R), Shipley Company (Shipley Company)) layer was exposed according to a pattern (193 n
m), and developed in the same manner as in Experimental Example 1. Next, the obtained pattern was inspected with a scanning electron microscope (SEM). Line / space pairs of 130 nm or more were well resolved and a clear profile was obtained. Exposure energy required for this formulation was in the range of 20~30mJ / cm ^2.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/11 503 G03F 7/11 503 7/38 511 7/38 511 7/40 521 7/40 521 H01L 21/027 H01L 21/30 502R (31) Priority claim number 09/266344 (32) Priority date March 11, 1999 (1999.3.11) (33) Priority claim country United States (US) (72 Inventor Pushkara Lao Vranashiy United States 12603 Pokiessey, New York Misty Ridge Circle 24 (72) Inventor Robert Dee Allen United States 95120 San Jose, California Calle del Connejo 6186 (72) Inventor Thomas Eye・ Wowlow United States 94587 California On City Royal Ann Drive 2656 (72) Inventor Julian Opitz USA 95126 San Jose de Marietta Avenue, California 1670 No. 3 (72) Inventor Richard A. Depietro United States 95120 San Jose Mount Holly, California 95120 Drive 6682 (72) Inventor Margaret Sea Lawson United States 12545 Milbrook P.O.Box, New York 1348 (72) Inventor Anne-Marie Muharter United States 12590 Wappingers Falls, New York Poppy Boulevard 506 (72) Inventor Joseph F. Maniscalco, United States 12449 Lake Catherine, New York Corwin Place, New York 1 (72) Inventor Mahmoud M. Hostist United States of America 12 601 Poughkeepsie, New York Martinelli Court 5 (72) Inventor George M. Jordamo United States 12533 Hopewell Junction Hollibury Drive, New York 14 (72) Inventor Hiroshi Ito, United States 95120 San Jose, California California Echo Ridge Drive 7149

Claims (41)

[Claims] 1. A photoresist composition comprising (a) a cyclic olefin polymer, (b) a photosensitive acid generator, and (c) a substantially transparent, bulky hydrophobic additive. 2. The cyclic olefin polymer comprises: i) a cyclic olefin unit having polar functionality; and ii) a cyclic olefin unit having an acid-labile group that suppresses solubility in an aqueous alkaline solution. The composition of claim 1 having the formula: Wherein the polar functional group, in which pK _a of about 13 or less acidic polar functional group, _a pK _a nonacidic polar functional group more than about 13 or selected from the group consisting of, The composition of claim 2. 4. The method according to claim 1, wherein the cyclic olefin unit i) is a carboxyl group, a sulfonamidyl group, a fluoroalcohol group,
The composition according to claim 2, comprising an acidic polar functional group having an acid group selected from the group consisting of: and other acidic polar groups. 5. The composition according to claim 4, wherein said acid group is a carboxyl group. 6. An acid-labile acid wherein said cyclic olefin unit ii) contains one group selected from the group consisting of tertiary alkyl carboxyl esters, tertiary cycloalkyl carboxyls, ester ketals, and ester acetals. 3. The composition according to claim 2, comprising a protecting group. 7. The composition of claim 1, wherein the bulky hydrophobic additive comprises a compound containing at least 10 carbon atoms and having an alicyclic group. 8. The method of claim 1, wherein said hydrophobic additive is a saturated steroid compound, a non-steroid alicyclic compound, and a non-steroid polyalicyclic compound having an acid labile linking group between at least two alicyclic groups. The composition of claim 1, comprising a compound selected from the group consisting of a compound. 9. The composition of claim 8, wherein said saturated steroid compound comprises at least one saturated C ₁₇ steroid alicyclic skeleton having at least one acid labile pendant protecting group. 10. The composition of claim 9, wherein said saturated steroid compound further comprises at least one additional pendant group selected from the group consisting of a hydroxyl group, a formyl group, an acetyl group, and a fluoroacetyl group. object. 11. The composition according to claim 8, wherein said saturated steroid compound comprises a steroid compound selected from the group consisting of cholate ester, ester-modified lysocholate, ester-modified cholate ester, and lysocholate having a space. 12. The saturated steroid compound is t-butyl lysocholate, t-butyl deoxycholate, t-butyl cholate, t-butyl-3-trifluoroacetyl lysocholate, t-butyl-3-acetyl lysocholate, t-butyl-3-pivalyl lysocholate, t-butyl-3,7,12-triformylcholate, t-butyl-tris- (3,7,12-trifluoroacetyl) cholate, and spaced lysocholate Structure, Embedded image 12. The composition of claim 11, wherein tBu is a tertiary butyl group. 13. The composition according to claim 12, wherein said saturated steroid compound is t-butyl-3-trifluoroacetyl lysocholate. 14. The composition of claim 8, wherein said hydrophobic non-steroidal cycloaliphatic compound comprises at least one non-steroidal C ₆ higher cycloaliphatic group. 15. The composition according to claim 14, wherein said hydrophobic non-steroidal cycloaliphatic compound comprises at least one non-steroidal C ₁₀ -C ₃₀ cycloaliphatic group. 16. The composition of claim 14, wherein said hydrophobic non-steroidal cycloaliphatic compound has at least one pendant protecting group which is acid labile. 17. The method according to claim 17, wherein the hydrophobic non-steroidal alicyclic compound has an acid-labile protecting group selected from the group consisting of a tertiary alkyl carboxyl ester, a tertiary cycloalkyl carboxyl, an ester ketal, and an ester acetal. 16. The composition of claim 15, comprising the composition. 18. The composition of claim 17, wherein said hydrophobic non-steroidal cycloaliphatic compound comprises a tertiary alkyl carboxyl ester. 19. The hydrophobic non-steroid polyalicyclic compound
Has at least two non-steroid C ₇Higher grade alicyclic
9. The composition according to claim 8, comprising a formula group. 20. The composition of claim 19, wherein said hydrophobic non-steroidal cycloaliphatic compound comprises at least two non-steroidal C ₁₀ -C ₃₀ cycloaliphatic groups. 21. The composition of claim 19, wherein said hydrophobic non-steroid polyalicyclic compound has two acid labile linking groups. 22. The hydrophobic non-steroidal alicyclic compound has an acid labile linking group selected from the group consisting of tertiary alkyl carboxyl esters, tertiary cycloalkyl carboxyls, ester ketals, and ester acetals. 22. The composition of claim 21 comprising: 23. The composition of claim 21, wherein said two acid labile linking groups comprise two linked tertiary alkyl carboxyl esters. 24. The composition according to claim 1, comprising about 5 to 25% by weight, based on the weight of the cyclic olefin polymer, of the hydrophobic additive. 25. The method according to claim 25, wherein the cyclic olefin polymer comprises
80 mol% of cyclic olefin units i) and from about 20 to 90
3. The composition according to claim 2, comprising mol% of cyclic olefin units ii). 26. The composition according to claim 2, wherein said cyclic olefin polymer consists essentially of a cyclic olefin unit i) and a cyclic olefin unit ii). 27. A patterned photoresist structure on a substrate, said photoresist comprising: (a) a cyclic olefin polymer; (b) a photosensitive acid generator; and (c) a substantially transparent photoresist. And a bulky hydrophobic additive. 28. The cyclic olefin polymer comprising: i) a cyclic olefin unit having a polar functional group; and ii) a cyclic olefin unit having an acid-labile group which suppresses solubility in an aqueous alkaline solution. 28. The photoresist structure of claim 27, comprising: 29. The hydrophobic additive is a saturated steroid compound, a non-steroid alicyclic compound, and a non-steroid polyalicyclic compound having an acid-labile bonding group between at least two alicyclic groups. 28. The photoresist structure of claim 27, comprising a compound selected from the group consisting of formula compounds. 30. A method of forming a patterned photoresist structure on a substrate, comprising: (A) providing the substrate with (a) a cyclic olefin polymer;
Applying a photoresist composition comprising (b) a photosensitive component and (c) a substantially transparent, bulky hydrophobic additive to form a photoresist layer on the substrate; B) exposing the substrate with radiation according to a pattern to generate an acid with the photosensitive component in the areas of the photoresist layer exposed with the radiation; and (C) exposing the substrate to an aqueous alkaline developer. Selectively contacting the exposed areas of the photoresist layer with the developer to form a patterned photoresist structure on the substrate. 31. The cyclic olefin polymer comprising: i) a cyclic olefin unit having a polar functional group; and ii) a cyclic olefin unit having an acid-labile group that suppresses solubility in an aqueous alkaline solution. Claim 3.
The method according to 0. 32. The hydrophobic additive, wherein the hydrophobic additive is a saturated steroid compound, a non-steroid alicyclic compound, and a non-steroid polyalicyclic compound having an acid-labile linking group between at least two alicyclic groups. 31. The method of claim 30, comprising a compound selected from the group consisting of a formula compound. 33. The radiation used in step (B),
31. The method of claim 30, wherein the ultraviolet radiation is less than 250 nm. 34. The method of claim 30, further comprising baking said substrate between steps (B) and (C). 35. A method for forming a structure of a patterned material on a substrate, wherein the material is selected from the group consisting of a semiconductor, a ceramic, and a metal, and (A) a layer of the material. Forming a substrate having: (B) (a) a cyclic olefin polymer on the substrate;
Applying a photoresist composition comprising (b) a photosensitive component and (c) a substantially transparent, bulky hydrophobic additive to form a photoresist layer on the substrate; C) exposing the substrate with radiation according to a pattern to generate an acid with the photosensitive component in the areas of the photoresist layer exposed with the radiation; and (D) exposing the substrate to an aqueous alkaline developer. Contacting, selectively dissolving the exposed area of the photoresist layer with the developer to form a patterned photoresist structure on the substrate; and (E) etching the pattern of the photoresist structure Transferring to a layer of the material through a space in the pattern of the photoresist structure. 36. The cyclic olefin polymer, comprising: i) a cyclic olefin unit having a polar functional group; ii) a cyclic olefin unit having an acid-labile group for suppressing solubility in an aqueous alkali solution. Claim 3.
5. The method according to 5. 37. The hydrophobic additive, wherein the hydrophobic additive is a saturated steroid compound, a non-steroid alicyclic compound, and a non-steroid polyalicyclic ring having an acid labile linking group between at least two alicyclic groups. 36. The method of claim 35, comprising a compound selected from the group consisting of a formula compound. 38. The method of claim 35, wherein said etching is performed by reactive ion etching. 39. providing at least one intermediate layer between said layer of material and said photoresist layer;
36. The method of claim 35, wherein etching comprises etching through the intermediate layer. 40. The method of claim 35, wherein said radiation has a wavelength less than about 250 nm. 41. The method of claim 35, wherein said substrate is baked between steps (C) and (D).