JP2850460B2 - Pattern formation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pattern forming method, and more particularly to a pattern forming method using a specific photosensitive material composition. The pattern forming method of the present invention can be applied to various fields of forming various patterns using the photosensitive material composition, for example,
The present invention can be used when an insulating layer is formed by photolithography in the manufacture of a semiconductor device (such as a semiconductor integrated circuit).

[Summary of the Invention]

The pattern forming method of the present invention has a good resolving power by exposing a photosensitive material composition containing a disilane derivative having a specific structure and a polyladder siloxane having a specific structure to light with an excimer laser beam, heating the composition, and then heating. In addition, an insulating layer pattern can be formed without requiring complicated steps.

[Background of the Invention]

Conventionally, a photosensitive material composition and a pattern forming method using the same have been used in various fields. For example, when an insulating layer is formed by patterning an electronic material, particularly a semiconductor device, a film is formed from the insulating layer material (for example, BPSG or PSG), and then a photoresist is formed on the film to perform patterning. In general, a resist pattern is obtained by applying the resist, exposing and developing a mask pattern on the resist, and then transferring the resist pattern by dry etching or the like to obtain an insulating layer having a required pattern. However, such a resist process involves a large number of steps as described above, and is extremely complicated. Therefore, in order to eliminate this complicated process, photosensitive insulating materials have been developed.
If the insulating material has photosensitivity, a pattern can be formed by exposing and developing itself without using a resist, which is advantageous in the process. Proposed as such are, for example, photosensitive polyimide and photosensitive siloxane (see Japanese Patent Publication No. 1-36983). These materials also have some heat resistance and are promising materials.

On the other hand, in recent years, miniaturization of the minimum size of semiconductor integrated circuits and the like has been demanded, and accordingly, the minimum size of the insulating layer has also been miniaturized. As one of the techniques for satisfying such a demand for miniaturization, lithography using short-wavelength exposure light has attracted attention. This is because a finer pattern can be formed by shortening the wavelength. In particular, KrF excimer laser lithography has recently received particular attention.

From the viewpoint of the necessity of the fine processing as described above, looking at the photocrosslinking component of the materials disclosed in Japanese Patent Publication No. 1-36983, which is a prior art, these materials are mainly bisazide compounds. The photosensitive component, which is
At the oscillation wavelength (250 nm) of the KrF excimer laser, the absorption was too large, so that there was a disadvantage that a good pattern could not be formed.

[Problems to be solved by the invention]

As described above, the insulating material composition having photosensitivity is extremely advantageous because it can be exposed and developed to form a pattern, but this type of conventional insulating material has a short wavelength for miniaturization. When using exposure light, there is a problem that good patterning cannot be performed.

The present invention eliminates the above-mentioned problems, and is capable of forming a pattern by lithography using an excimer laser light that is short-wavelength light, for example, a KrF excimer laser light or an ArF excimer laser light. An object of the present invention is to provide a pattern forming method capable of forming a layer.

[Means for solving the problem]

The present invention provides a photosensitive material composition containing at least a disilane derivative represented by the following general formula (1) and a polyladder siloxane having a repeating unit represented by the following general formula (2) in a molecule. Coated on a substrate, exposed by excimer laser light through a mask, developed, heated,
Or by heating while irradiating far ultraviolet rays,
The above object has been achieved by forming a patterned insulating layer.

General formula (1) In the general formula (1), R ^{1 to} R ⁶ each independently represent an aryl group or an alkyl group (each group includes those having a substituent). However, at least two of R ^{1 to} R ⁶ represent an aryl group (including those having a substituent).

General formula (2) In the general formula (2), R ²¹ and R ²² each independently represent a vinyl group, an allyl group, or a chloromethyl group (each group includes those having a substituent).

 Hereinafter, the present invention will be described in more detail.

In the present invention, the ginran derivative represented by the general formula (1) functions as a photoreactive dye. That is, it is considered that this compound is cleaved by the energy of exposure light to generate a radical, which acts to attack an unsaturated group of the compound having a repeating unit represented by the general formula (2). In the present invention, as such a disilane derivative, one in which at least two of R ^{1 to} R ⁶ are a phenyl group can be preferably used, and specifically, the following compounds can be preferably used. However, as a matter of course, the present invention is not limited to the following example.

In the present invention, as the polyladder siloxane represented by the general formula (2), those represented by the following general formula (2-1) are representative.

General formula (2-1) In the above formula, R is an alkyl group or an aryl group.
R ²¹ and R ²² have the same meaning as in general formula (2). n is a positive integer.

In general, the compound represented by the general formula (2-1) may be a terminal trialkyl (or aryl. A mixed form of alkyl and aryl, preferably R is an alkyl group) silyl It is a polyladder siloxane. In the general formula (2-1), the repeating unit represented by the general formula (2) does not necessarily have to have the same R ²¹ and R ²² . Further, in the general formula (2-1), it is not necessary that all the repeating units have R ²¹ and R ²² , and R ²¹ and R ²²
May be included.

Preferably, both R ²¹ and R ²² are allyl groups which may have a substituent, or both are vinyl groups,
Alternatively, a mixture of an allyl group which may have a substituent and a vinyl group is preferable. R is preferably a methyl group.

There is no limitation on the molecular weight of the polyladder siloxane used,
Optional. In general, when the molecular weight is large, the sensitivity at the time of pattern formation is large, but the solubility is reduced. For example, those having a molecular weight of about 20,000 can be preferably used.

The polyladder siloxane used in the present invention can be obtained as follows. That is, trifunctional vinyl silane,
Alternatively, trichlorosilane such as allylsilane or chloromethylsilane (in this case, the trifunctional substituent is chlorine) is hydrolyzed with an inorganic alkali such as NaOH or an organic alkali such as triethylamine or pyridine to partially terminate hydroxyl groups. Is synthesized (polymerized). By protecting the hydroxyl group of the compound thus obtained with trialkylchlorosilane or the like, the polyladder siloxane used in the present invention can be synthesized. In general, at the time of polymerization, a method of further polymerizing after synthesizing a prepolymer once is adopted.

The radical generation reaction for a vinyl group, an allyl group, or a chloromethyl group contributing to pattern formation is performed using a disilane derivative that functions as a photoreactive dye represented by the general formula (1). In this case, a phenyl-substituted disilane is used. Derivatives are preferred. Some of these materials are commercially available, but are generally synthesized by dropping the corresponding chlorosilane in a kerosene dispersion of an alkali metal (lithium). In addition, when a methyl group may be included in the molecular structure, it can be synthesized by a method in which chlorine in the methyl-substituted disilane fraction is replaced with an aryl Grignard reagent.

EXAMPLES Examples of the present invention will be described below. However, needless to say, the present invention is not limited to the embodiments described below.

Embodiment 1 In this embodiment, the present invention is applied to forming a fine insulating layer pattern of a semiconductor integrated circuit device. In the present example, in particular, the present invention was applied to KrF maxima laser lithography, and the photosensitive composition was configured to be sensitive to KrF excimer laser light.

In this embodiment, as described below, a polyladder siloxane having a repeating unit represented by the general formula (2) is used.
A resin was formed. That is, a prepolymer obtained by hydrolyzing allyltrichlorosilane is polymerized with triethylamine as a catalyst, and the resulting hydroxypolyallyl ladder siloxane having a weight average molecular weight of 20,000 is used. A protected resin (that is, the terminal OH was replaced by a trimethylsilyl group) was prepared.

To 10 g of the above resin, 2 g of 1,1,2,2-tetraphenyldimethyldisilane, which is a disilane derivative represented by the general formula (1), was added as a photoreactive dye, and 120 ml of xylene was added.
To give a photosensitive silicone resin composition. This is the photosensitive material composition of the present invention used in this example. This is used as a composition for forming an insulating material in the examples of the present invention.

Next, in this example, the above composition was spin-coated using a spinner on a silicon substrate on which an aluminum wiring layer was formed, dried at 110 ° C. for 2 minutes on a vacuum absorption / absorption type hot plate, and dried to a thickness of 1.0 μm. A film was formed. A KrF excimer laser reduction projection exposure system (NA: 0.37,
The pattern was exposed using (σ: 0.5) (exposure amount: 200 mJ).
/ cm ² ). Next, 15% in MIBK (methyl isobutyl ketone)
Using a developing solution in which% DMF (dimethylformamide) was mixed and dissolved, development was performed for 2 minutes by a spray method, followed by rinsing with isopropyl alcohol and heat treatment at 400 ° C. for 1 hour. As a result, a good patterned insulating layer could be obtained.

In addition, a separate example was given in which 1,2-diphenyltetramethyldisilane, which is a disilane derivative represented by the general formula (1), was used as a photoreactive dye. In this case,
Except that the exposure amount was 150 mJ / cm ² , it could be carried out in the same manner and gave similarly good results.

A good pattern of an insulating layer was also obtained by using far ultraviolet light irradiation for heating.

In the above examples, the composition of the present invention was used as a patternable insulating layer forming material, and the conventional PSG or B
PSG itself does not have photosensitivity, so it requires a photoresistor, whereas the composition of the present invention itself is exposed and patterned, so no resist is required, and it is made by an extremely simple process it can. Furthermore, it has higher heat resistance than conventional photosensitive polyimide resins of this type, and can be used as a substitute for glass containing impurities (P, As, B, etc.) which has been conventionally used as an insulating material.

In the above example, the present invention was used when an insulating layer pattern was formed on a substrate having wirings and the like, but the photosensitive material composition of the present invention may also be used as an upper layer resist for a two-layer resist method. Available. For example, the present invention can be carried out by using the composition of the present invention as an upper layer resist of a two-layer resist and using a hard-baked photoresist as a lower layer.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a photosensitive composition that can be patterned by simple steps and a pattern forming method using the same.

Claims (1)

(57) [Claims] 1. A photosensitive material composition comprising at least a disilane derivative represented by the following general formula (1) and a polyladder siloxane having a repeating unit represented by the following general formula (2) in a molecule: Is applied on a substrate, exposed by an excimer laser beam through a mask, developed, heated,
Or by heating while irradiating far ultraviolet rays,
A pattern forming method, comprising forming a patterned insulating layer. General formula (1) In the general formula (1), R ^{1 to} R ⁶ each independently represent an aryl group or an alkyl group (each group includes those having a substituent). However, at least two of R ^{1 to} R ⁶ represent an aryl group (including those having a substituent). General formula (2) In the general formula (2), R ²¹ and R ²² each independently represent a vinyl group, an allyl group, or a chloromethyl group (each group includes those having a substituent).