JPH01201337A - Pattern forming material and pattern formation - Google Patents

Abstract

PURPOSE:To obtain the title material having a high sensitivity and a high resolution to an actinic radiation and used in the production of semiconductor elements, magnetic bubble elements, etc., by adding a specified o-naphthoquinone compound to a specified silicone resin. CONSTITUTION:This pattern forming material is obtained by adding an o- naphthoquinone compound of formula V (wherein Z is OH, OCl, OF, formula VI, formula VII, formula VIII, formula IX or the like, and x and y are positive numbers) to a silicone resin of formula I or II {wherein X is formula III, formula IV [wherein R is a (substituted)hydrocarbon group] or COOH, R'-R'''' are each OH, an alkyl or a phenyl, l, m and n are each 0 or positive integer provided that l and m must not be 0 at the same time, and p is a positive integer}. This material can form a negative pattern of a high sensitivity and a high resolution by irradiating it with an actinic radiation such as ultraviolet rays in a vacuum, an inert gas or air and optionally heating it, irradiating the entire surface with light and developing it with an alkali.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pattern forming material and a pattern forming method used in manufacturing semiconductor elements, magnetic bubble elements, optical application parts, and the like.

[Conventional technology]

Conventionally, in the production of ICs, LS, I, etc., a substrate to be processed is coated with an organic composition such as a polymer compound called a resist, and a latent image is formed on the resist by irradiating it with high-energy radiation in a pattern. After developing the resist film to form a patterned resist film, the substrate to be processed is immersed in a corrosive solution, and the parts of the substrate that are not covered by the resist are chemically etched or doped with impurities. It's here.

However, as integrated circuits have become more highly integrated in recent years, it has been desired to form ever finer patterns. In particular, when doping ions at high acceleration or obtaining a pattern with a high shape ratio, which is the ratio of the height to width of the pattern, the resist film thickness must be thick. In other words, in order to capture high-speed ions without them reaching the substrate, the resist film must be thick, and dry etching eliminates the side etching that is inevitable with the wet etching method, which involves immersing the resist in a corrosive solution. In other words, even when you want to realize a pattern with a high shape ratio using reactive sputter etching using gas plasma, ions, etc.
Since the resist portion is also etched during dry etching, the resist film thickness must also be increased. However, with conventional resists, the resolution decreases as the film thickness increases, making it impossible to form a resist pattern with a high shape ratio.

In order to solve this problem, a method has been proposed in which the number of layers of resist is increased rather than one, and a resist pattern with a high shape ratio is formed. That is, a thick film of an organic polymer material is formed as the first layer, a thin film of resist material is formed on the second layer, and then the second layer of resist material is exposed to high-energy rays and developed. By dry etching the first NI organic polymer material 'Pr using the resulting pattern as a mask, a pattern with a high shape ratio is obtained.

However, with this method, when a normal resist is used for the second layer, it may not be possible to obtain a large ratio of dry etching speeds, that is, selectivity, between the materials of the first and second layers, or it may take a long time to increase the dry etching rate. Etching time was required.

For example, according to Akiya et al. (Preliminary presentation of the 45th Annual Meeting of the Japan Society of Applied Physics, P213), polymethyl methacrylate (hereinafter abbreviated as PMMA) t-, 2nd J
It has been reported that when dry etching is performed using carbon tetrachloride as an etching gas using a thread made of chloromethylated polystyrene for the fl, the selectivity is very low and a resist pattern with a high shape ratio is formed. are doing. However, in this case, since the etching speed of PMMA is also low, it takes time to etch thick PMMA'ji, and there is also a drawback that the underlying substrate is also etched with carbon tetrachloride at the same time.

As a multilayer resist system using oxygen plasma, a three-layer resist has been proposed in which an inorganic layer having high oxygen plasma resistance is provided between a first layer of thick polymer material and a second layer of resist. In this case, the inorganic layer is dry-etched using a pattern formed with a resist material as a mask using a gas such as carbon tetrachloride-carbon tetrafluoride or argon, and then the organic polymer material layer is etched using an A2 wire using the inorganic layer pattern as a mask. will be dry etched.

In this case, the boron plasma can quickly etch the #1 thick film material, and the substrate is hardly etched, so the end point of etching can be made clear. However, it has the disadvantage that the number of steps increases significantly.

On the other hand, when a silicone resist with high resistance to dry etching by oxygen plasma is used as the second layer, tj, W
Since oxygen plasma can be used when dry etching the organic polymer material of the first layer using the I2N resist pattern as a mask, a resist pattern with a high shape ratio can be formed in a short time and with a small number of steps.

[Problem to be solved by the invention]

However, currently known silicone resists have glass transition temperatures considerably lower than room temperature, and polymers with low molecular weights are liquid or semi-liquid, making them extremely difficult to handle and having poor sensitivity to high-energy radiation.

On the other hand, when the molecular weight is increased, it becomes rubbery and is slightly easier to handle, and the sensitivity also increases, but it rarely has disadvantages such as swelling in the developing bath, resulting in a decrease in the resolution of pattern ridges, etc. . Furthermore, in order to increase the sensitivity of the cross-linking reaction, a functional group having a high chain reactivity such as a vinyl group is introduced into the side chain, which also causes a decrease in resolution.

Yumei Moto was created to eliminate these drawbacks, and its purpose is to provide high sensitivity and high sensitivity to high energy rays.
It is an object of the present invention to provide a pattern forming method using an energy ray sensitive material which has high resolution and is highly resistant to dry etching by accumulated plasma.

[Means to solve the problem]

To summarize the present invention, the first invention of the present invention relates to a silicone resin, which has the following general formula 1 or 2: (wherein R represents a hydrocarbon group or a substituted hydrocarbon group) and a carboxyl resin. R゛, R#, R- and R'' are the same or different and represent one group selected from the group consisting of hydroxyl group, alkyl group and phenyl group. , tlm and n indicate 0 or a positive integer, and t and m cannot be 0 at the same time% pf'i
positive integer].

Further, the second aspect 8A of the present invention relates to a pattern forming material, and includes a silicone resin of the invention of Ml and the following general formula 1: C, H.

↓ represents the group 1a selected from the group ↓, where X and y are the same or different integers).

The sixth invention of the present invention relates to a pattern forming method, which includes a step of coating the pattern forming material gold of the second invention on a processing substrate or a thick organic polymer layer, and applying high energy to the process, process of irradiating the entire surface with ultraviolet rays after irradiation with high energy rays,
and development with an alkaline aqueous solution to completely form a negative pattern in the high-energy ray irradiation area.

Examples of high-energy rays include ultraviolet rays, X-rays, and electron beams. For example, ultraviolet? Using fMt-, irradiation is performed in a pattern in vacuum or under an inert gas atmosphere. Alternatively, ultraviolet light may be irradiated in a pattern in the atmosphere, followed by heating. If the holes are irradiated in a pattern in a vacuum or under an inert gas atmosphere, a heating step may be added after that.

The pattern forming process is shown in Fig. 1. 0, that is, Fig. 1 is a process diagram showing one example of the pattern forming process in the present invention. 5 is a pattern forming material, 4 is a thick organic polymer layer or substrate, 5 is an ultraviolet ray, and 6 is a negative pattern. First, the above-mentioned pattern forming material is applied to a thick organic polymer layer or processed substrate, and then patterned with high energy rays in a vacuum, an inert gas, or the atmosphere. At this time, a hiatus occurs only in the irradiated area (a). If irradiation is performed in vacuum or in an inert gas, heat treatment is performed directly, and if irradiation is performed in the atmosphere, heat treatment is performed. After that, the entire structure is irradiated with ultraviolet rays in the atmosphere (b).

Then, alkaline development is performed to form a negative pattern in which a residual film remains only in the high-energy ray irradiated areas (C).

In the present invention, the pattern forming material adopts a polysiloxane structure to improve O, RIE resistance, and also incorporates a silicone polymer with a high Tg t'' by introducing many phenyl groups into the side chain. The siloxane polymer represented by the above formula 1% has a siloxane structure in the chain, so it has high resistance to O, RIE.
Further, since there are many 91+1 chains of phenyl groups, the Tg is 69 or more than N-, and a smooth film can be formed without being viscous, and can be used as a resist. Because the hydrophilic silanol group is contained, it is soluble in alkaline water baths.

Therefore, the above orthonaphthoquinone compound (1) e
The composition added to the siloxane polymer represented by formula 1 and (■) is a photosensitive a resin composition, and upon irradiation with ultraviolet rays, the orthonaphthoquinone compound in the irradiated area becomes the corresponding indenecarboxylic acid and becomes alkali-soluble, and it becomes alkali-soluble in alkaline development. removed. - It has been found that when the pattern forming material used in the invention is irradiated with ultraviolet rays in a vacuum or an inert gas, the alkali solubility described above decreases. In addition, even if heat treatment is performed after UV irradiation in the atmosphere,
Solubility in Al decreased. A negative pattern can be formed by exposing in a pattern under these conditions, then exposing the entire surface to ultraviolet light and developing with alkali. If heat treatment is performed after exposure in vacuum or in an inert gas, the alkali solubility will be further reduced and the pattern forming effect will be greater. The negative pattern obtained by this process exhibits high screenability because it does not swell during development. In this pattern forming material, the amount of the orthonaphthoquinone compound added is usually 5 to 40% by weight. 5N
If the amount is less than 40% by weight, the dissolution of the polymer compound in the alkaline developer cannot be suppressed, and if it exceeds 40% by weight, the S1 content as a pattern forming material decreases, resulting in a decrease in oxygen plasma resistance, resulting in disadvantages.

The method for producing the siloxane polymer represented by the general formula 1 used in the present invention includes cyclic phenylsiloxanes such as hexaphenylcyclotrisiloxane and octaphenylcyclotetrasiloxane, alkali metal hydroxides such as gold potassium hydroxide, butyl lithium, etc. A conceivable method is to perform open polymerization with an alkylated alkali metal and modify the obtained polydiphenylsiloxane.

Further, instead of using cyclic phenylsiloxane alone, it may be copolymerized with tetramethyltetraphenylcyclotetrasiloxane, octamethylcyclotetrasiloxane, or the like.

C)-81E3(
A conceivable method is to modify lerphenylsilsesquioxane polymer, which is easily obtained by hydrolyzing a silane compound (E is ct or 0CR3).

Next, we will show examples of the production of siloxane polymers represented by general formulas 1 and ◇ Production Example 1 In a 9300-meter flask equipped with a stirring point, a thermometer, and a dropping funnel, 1st 1 liter of anhydrous aluminum chloride and 50 liters of acetyl chloride were added.
-1- Stir. Next, polyphenylsilsesquioxane (glass resin GR950,
Owens-Illinois Co.) 5tf acetyl chloride 50-
Gradually add the solution dissolved in The reaction is allowed to proceed while maintaining the temperature at 25°C. Hydrogen chloride is generated as the reaction progresses.

After reacting for 3 hours, it was cooled and the contents were t-jIF! Pour into ice water containing rIR. Stir well to decompose the aluminum chloride, and after confirming that the ice water is acidic, separate the precipitated polymer tF. Wash thoroughly with dilute hydrochloric acid and water, and finally dry in a vacuum dryer. The obtained polymer had a molecular weight of 980. 16706 in the infrared absorption spectrum (IR)
Absorption of a carbonyl group was observed at R-1, and absorption of a methyl group was observed at δ=2.4 by NMR, confirming acetylation. The acetylation rate at this time was estimated to be 60% by NMR. In addition, OH absorption was observed at 3400011-'' by IR, and OH of silanol was observed at around 6.5 ppm by NMR, confirming the presence of silanol groups.0 Production Example 2 Stirrer, thermometer, dropping In a 500mm flask equipped with a funnel, stir 25gt of stannic chloride and 50wtt of anhydrous vinegar.Next, diphenylsilanediol 6f was soaked in 50mm of acetic anhydride and gradually drop IcM. An acetylated polysiloxane was obtained in the same manner as in Example 1.

The molecular weight of the obtained polymer was 1500, and the acetylation rate was 42%. It was confirmed by IR and NMR that silanol groups were present.

Production Example 3 Acetylpolyphenylsilsesquioxane obtained in Production Example 1 6f't-10% sodium hypochlorite water bath g1
00- and reflux for 12 hours. When a salt rIIt- is added to the resulting clear liquid, a precipitate is formed. A yellowish white solid was obtained. In the infrared absorption spectrum, the absorption of the carbonyl group at 1670 an-'' disappeared and the absorption of the carboxyl group was observed at 1700 an-'', indicating carboxylation. Yield 70
%. IR%NMR↓, it was confirmed that there was a silanol group.

Manufacturing example 4 Manufacturing? Add 6tff of the acetylated polydiphenylsiloxane obtained in step 12 to 100+wj of a 10% aqueous solution of sodium hypochlorite and reflux for 12 hours.
Carboxylation was carried out similarly to lJ5. Yield 6
The carboxylated products obtained in Production Example 3 and Production fli4 are soluble in alkaline aqueous solution, methanol, and ethanol.
It was insoluble in other organic solvents.

IR%NMR analysis confirmed that it was a silanol group.

Production Example 5 Dissolve acetylpolyphenylsilsesquioxane 5tf obtained in Production Example 1 in tetrahydrofuran 1001stVC,
5f (D LiAm 4') was added to this, and a rapid flow was carried out for 3 hours. After the reaction was completed, it was poured into ice water containing 5% hydrochloric acid to obtain a yellowish white solid. 1 observed in the raw material in the infrared absorption spectrum
670 all-” carbonyl absorption disappears, 310
Absorption due to OH groups was observed in the vicinity of 0 to 3400 cIn-', and reduction was confirmed by OIR% NMR, which confirmed the presence of silanol groups.

Production Example 6 Acetylated polydiphenylsiloxane 5 obtained in Production Example 2
Dissolve t in 100% of tetrahydrofuran, add 3t to this
of LiAα4 was added and the mixture was completely refluxed. After the reaction was completed, the polymers obtained in Production Example 5 and Production Example 6 were poured into ice water containing 5% salt to obtain a yellowish white solid. Met. IR, NMR processing, and silanol group formation were confirmed.

Production Example 7 An acetylated polydiphenylsiloxane was obtained in the same manner as in Production Example 1 except that in place of the polyphenylsilsesquioxane, letapolydiphenylsiloxane (molecule 1i3QOo) obtained by ring-opening polymerization of a cyclic siloxane was used. IR,
The presence of silanol groups was confirmed by NMR.

Production Example 8 A globionylated polyphenylsilsesquioxane was obtained in the same manner as in Production Example 1, using flopionyl chloride in place of acetyl chloride. IR% NMR technology confirmed the presence of silanol groups.

Production Example 9 A propiomolated polydiphenylsiloxane was obtained in the same manner as in Production Example 7 except that globionyl chloride was used in place of acetyl chloride. IR.

NMR confirmed the presence of silanol groups.

[Implementation f series]

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples. Coat on wafer and heat to 80℃
It was grilled for 20 minutes. After pre-veta, the sample was irradiated with ultraviolet rays from an ultra-high pressure mercury lamp in the atmosphere, in the middle of the atmosphere, or in argon gas. After irradiation, it was heated in a constant temperature bath at 110°C for 30 minutes. 500 mJ/cv with Xe lamp after heating? The entire surface was irradiated with the irradiation lid. The irradiated sample! Microposit 2
401 (manufactured by Sibley) and a developer having a water ratio of 171, respectively, and the irradiation amount at which the remaining film in the irradiated area became 50% of the initial film thickness was defined as the sensitivity. The resolution was determined by measuring the minimum pattern size that could be resolved using a line-space pattern.

It does not depend much on the ultraviolet irradiation atmosphere, and the sensitivity is 120 to 150 mJ/
car'', resolution is α6 to 0.8 Am, 6th order.If irradiated in vacuum or argon gas and without heat treatment, the sensitivity will decrease by about 30% fC.

Example 2 Using the phenylsilsesquioxane polymer according to Preparation Example t, in the orthonaphthoquinone thread compound represented by the general formula 1, group 2 has the following structure: (1) -〇H,ra)-octJ (31 -OF.

C Tomi H.

[Compound No. 15 is a compound represented by Niho, and has an average molecular weight of 970, and has a ratio of ester moiety (polymerization degree X) to free phenol moiety (polymerization degree y) in formula (g). The ratio of FJ6:4) was added at a weight of 20%, and the sensitivity to ultraviolet irradiation in vacuum (irradiation t at 50% remaining film) was measured in the same manner as in Example 1. . The results are shown in Table 1.

Each is an α7 μm line-space tm image.

Example 3 AZ-1550 resist (manufactured by Sibley) was coated on a silicon wafer to a thickness of 2 μm and heated at 200° C. for 30 minutes to insolubilize it. On top of this AZ resist, the resist material used in Example 911 was applied to about [12
Coat to a thickness of μm and pre-bake at 80°C for 20 minutes.

After prebaking, UV irradiation from an ultra-high pressure mercury lamp and xenon light irradiation were performed in a vacuum chamber, and development was performed with a developer having the same composition as in Example 1. A pattern with a minimum line width α of 7 μm was formed on the upper resist material. Ta. Thereafter, the resist pattern tAZ resist gold was etched using a parallel plate type sputter etching apparatus using oxygen gas as an etchant gas.

By etching for 15 minutes at a gas pressure of 20 mtorr, the AZ resist in the areas not covered by the resist pattern completely disappeared. Even with a resist material of f deviation, an α7 Am lie y-space pattern with a thickness of about 2 μm could be formed.

〔Effect of the invention〕

As explained above, the pattern forming material used in the method of the present invention uses an alkali-soluble siloxane polymer and contains orthonaphthoquinone thread compound gold. A negative pattern with high sensitivity and high resolution can be formed by irradiating in the atmosphere, heating if necessary, irradiating the entire surface with light, and developing with alkali.

Furthermore, since it contains silicon, it has high tR plasma resistance, and therefore can be used as an upper layer resist of a two-layer resist. Since the two-layer resist has high resistance to dry etching using CF4 or the like as the lower layer and has a thick organic polymer layer, a pattern having an extremely high shape ratio t- can be formed on a stepped substrate. Therefore, according to the present invention, it is possible to achieve
It has the remarkable effect of being sensitive to pots, having a high shape ratio, and forming a bamboo pattern that is resistant to dry etching, such as CF.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing one example of a pattern forming process in the present invention. 1: Pot energy gland, 2: Latent image area generated by high-energy beam irradiation, 5 = Pattern forming material, 4: Organic polymer dove or substrate, 5: Ultraviolet rays, 6: Negative pattern patent applicant Nippon Amboshi Telephone Co., Ltd. company

Claims (1)

[Claims] 1. The following general formula I or II: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[II] [In the formula] X is the same or different, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼From the group consisting of a group (wherein R represents a hydrocarbon group or a substituted hydrocarbon group) and a carboxyl group Indicates one selected group, R'
, R″, R″′ and R″″ are the same or different, hydroxyl group,
represents one type of group selected from the group consisting of an alkyl group and a phenyl group, l, m and n represent 0 or a positive integer,
A silicone resin characterized in that l and m are never 0 at the same time, and p is a positive integer. 2. The silicone resin according to claim 1 and the following general formula III
: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [III] (In the formula, Z is -OH, -OCl, -OF, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc. There are ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Indicates one type of group selected from the group consisting of, x and y are the same or a different positive number). 3. A step of applying the pattern forming material according to claim 2 onto a processed substrate or a thick organic polymer layer, a step of irradiating it with high energy rays in a pattern, and after irradiating the high energy rays, exposing the entire surface to ultraviolet rays. A pattern forming method comprising the following steps: and developing with an alkaline aqueous solution to form a negative pattern in a high-energy ray irradiated area. 4. The pattern forming method according to claim 3, wherein the high-energy rays are ultraviolet rays, and the irradiation is carried out in a pattern in a vacuum or in an inert gas atmosphere. 5. The pattern forming method according to claim 4, further comprising the step of heating after irradiating the high energy beam. 6. The pattern forming method according to claim 3, wherein the high-energy rays are ultraviolet rays, and the method includes a step of irradiating the high-energy rays in a pattern in the atmosphere and then heating them.