JPH06242610A - Organic material film having bleaching effect of discoloring effect to light - Google Patents

Abstract

PURPOSE:To enable the org. material film to be directly provided without requiring an intermediate layer for preventing it being mixed and to be removed by direct development by using a xylene-soluble resin as a binder and using dyestuff of a specific disilane system as photobleachable and photodiscolorable dyestuff. CONSTITUTION:At least the xylene-soluble resin is used as the binder of the org. material film having a bleaching effect or discoloring effect to light. The dyestuff of the disilane system is at least used as the photobleachable and photodiscolorable dyestuff. The preferable disilane derivatives usable as the photodiscolorable dyestuff are expressed by formulas I to III. In the formulas I to III, Me denotes a methyl group; Ph denotes a (substd.) phenyl group. Particularly the disilane deriv. which is expressed by the formula I and in which Ph is a phenyl group has good performance and is relatively inexpensive and practicable. The compd. expressed by the formula II has good performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic material film having a bleaching action or a fading action against light. The organic material film of the present invention is, for example, provided in the case of manufacturing an electronic material (semiconductor device or the like), for example, on a photoresist in order to increase the contrast at the time of exposure and to make the processed shape of the pattern favorable. Can be used.

[0002]

2. Description of the Related Art Miniaturization is progressing in various fields. For example, in the field of semiconductor devices, miniaturization and integration of semiconductor integrated circuits have been reduced to a level of 0.35 μm. Along with this, many technological developments have been made in the lithography technology. For example, KrF excimer laser lithography is drawing attention. This is because the oscillation wavelength of the KrF excimer laser is shorter than that of the conventional g-line and i-line, and the resolution can be improved. In addition, as a technique for improving the resolution, CEL (C
ontrast enhanced lithogra
PHY) technology is known. this is,
Providing a film that has a bleaching action on light (the property of being bleached by light of that wavelength) or a film having a bleaching action on light (the property of being bleached by light of that wavelength) on the photoresist, and then exposing and developing , A technique for forming a resist pattern. According to this, the exposure light bleaches or discolors the color to that light, so that the apparent contrast is improved, and if the exposure amount is the same, the contrast is increased and the obtained pattern shape becomes good.

By the way, when using this CEL technology,
In order to provide a film having a bleaching action or a fading action to light (hereinafter collectively referred to as photo-bleaching property) on the resist, the photo-bleaching film and the resist film are not mixed with each other. It is necessary. Therefore, the solvent of the resist is
If the photobleachable dye to be used is also soluble, the two will be mixed, so this must be avoided. For example, polymer Eng. and Sci. ，
July 1989, vol. In the technique disclosed on page 902 and below, a resist is first coated with an intermediate layer for preventing mixing, and further, an intermediate layer for preventing mixing is formed on the resist so that the light transmittance is increased by light erasing at the exposure wavelength. So-called CEL layer is formed by applying various materials, and after exposure, CE
The resolution is improved by peeling off the L layer together with the intermediate layer used as the barrier layer and developing. The technique presented in this document is xylene soluble,
Moreover, it dissolves in an alkaline developer and can be used in Chinese rosin (Chin
By using a substance called "ese resin" as a binder, a simple process such as direct application to resist and direct development is made possible.

[0004]

Problems to be Solved by the Invention Conventional CE described above
The L technique has a problem that needs further improvement. One is that in the prior art, an intermediate layer is required to prevent mixing with the resist layer, which makes the process complicated. A technique capable of forming a film directly on a resist without the need for an intermediate layer is desired. Further, in the above technique, Chinese rosin is used as the binder, but it has the drawback that it cannot be used depending on the resist because it shows acidity (which is a carboxylic acid). That is, in order to increase the resolution,
If you want to expose with KrF excimer laser light,
A so-called chemically amplified resist is desirable as the resist used for this exposure wavelength. The chemically amplified resist refers to a resist that participates in the next reaction and acts so as to amplify the reaction, and generally has a photo-acid generator to perform a photoreaction. As described above, the chemically amplified resist generally generates an acid by light, and the acid promotes a crosslinking reaction. Therefore, when an acidic substance is applied, its catalytic action causes crosslinking to already proceed on the surface before exposure, and the substance does not act as a resist. Not only Chinese rosin, but also acidic ones cannot be used for chemically amplified resists, so there is a problem of lacking versatility. And,
Since it is difficult to use the excimer laser exposure, there is a problem that there is a limit in improving the resolution.

CE for KrF excimer laser exposure
As the L material, there is a material (4p-K-5 on page 499 of the same proceedings) which has been announced as a submicron lithography technology by an excimer laser at the 49th Academic Meeting of the Applied Physics Society of Japan in autumn 1988. This is also a type of CEL material that cannot be directly applied, which complicates the process. Further, the same applies to the one described in JP-A-61-69130. Incidentally, in JP-A-61-198237,
There is a description of a technique for removing the CEL layer.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above problems and
It is a photobleaching / photobleaching organic material film, and even when it is provided on the resist to improve contrast, it can be directly provided without the need for an intermediate layer for preventing miscibility, and can be removed by direct development. It is intended to provide an organic material film which can also be formed.

[0007]

The organic material film of the present invention is an organic material film having a bleaching action or a fading action to light, wherein the organic material film uses at least a xylene-soluble resin as a binder, and At least a disilane dye is used as a bleaching / fading dye.

In the present invention, a photobleachable dye which is a photobleaching / fading dye.
As the dye), various kinds can be used.

The preferred photobleachable dye is a disilane derivative. This type of compound exhibits an effective photo-bleaching property with respect to the wavelength of the KrF excimer laser light, and therefore can be effectively used for forming a resist pattern having high resolution. Among these, a substituted disilane substituted with an aromatic group is more preferable, and a substituted disilane having two or more aromatic groups as a substituent is particularly preferable.

Preferred disilane derivatives which can be used as the photo-decolorizable dye in the present invention are those represented by the following general formulas (1) to (3). General formula (1) (Ph) ₂ MeSi-SiMe (Ph) ₂ General formula (2) (Ph) ₃ Si-Si (Me) ₃ General formula (3) (Ph) ₃ Si-SiPh (Me) ₂ General formula (4) Ph (Me) ₂ Si-SiPh (Me) ₂

In the general formulas (1) to (3), Me represents a methyl group and Ph represents a phenyl group which may have a substituent. The disilane derivative represented by the general formula (1) in which Ph is a phenyl group has good performance,
It is relatively inexpensive and practical. The compound represented by the general formula (2) has good performance.

The photo-bleaching dye used in the present invention may be any one as long as it has photo-quenching properties with respect to a desired wavelength, but xylene-soluble dyes are preferable. General formula (1)
The compounds represented by (3) to (3) may have any substituents on the phenyl ring, but are preferably xylene-soluble.

The organic material film of the present invention uses at least a xylene-soluble resin as its binder. Generally, the lower the molecular weight, the better the solubility in xylene. It is also possible to use a resin insoluble in xylene together.
However, it is preferable to form the film as a xylene-soluble organic material film as a whole.

The binder used is preferably an alkali-soluble resin, particularly novolac resin, polyvinylphenol resin, styrene-maleic acid copolymer and the like.

The mixing ratio of the binder resin and the photo-bleaching dye, especially the disilane derivative, is more effective and preferable as the amount of the disilane derivative is larger, but there is a limit in the compatibility of the disilane derivative. It is particularly preferable that the resin: disilane derivative has a blending ratio of about 2: 1 to 4: 1. If too much disilane derivative is added, phase separation may occur. If the disilane derivative is reduced too much, absorption (25
The effect is not so great because the absorption at 0 nm) is reduced.

In the practice of the present invention, it is preferable that a mixture of the binder resin and the photo-bleaching dye is dissolved in an appropriate amount of xylene, filtered, and used for feces.

The organic material film of the present invention can be conveniently used by coating it on a photoresist or providing it by other means to enhance the contrast and resolution. Even if it is formed directly on the resist, there is little risk of mixing. For a chemically amplified resist, an appropriate photo-bleaching organic material film that can be directly coated and formed has not been developed so far.However, even if the organic material film of the present invention is directly formed on a chemically amplified resist, it is chemically amplified. It can be effectively used without being mixed with a resist or causing a cross-linking reaction in a chemically amplified resist. Therefore, it can be embodied as a high-resolution technique of exposing with a short wavelength excimer laser beam using a chemically amplified resist.

In a preferred embodiment of the present invention,
The organic material film of the present invention is directly formed on the chemically amplified resist by spin coating or the like, exposed to light, and after necessary baking (PEB), developed. At this time, for the development, a simple means for directly developing with an alkaline developer can be used.

[0019]

EXAMPLE An example of the present invention will be described below together with a comparative example. However, as a matter of course, the present invention is not limited to the examples described below.

Example 1 In this example, the CEL technique was embodied by using the organic material film of the present invention in the manufacture of a miniaturized and integrated semiconductor device.

10 g of a low molecular weight novolak resin having a molecular weight of 300 to 500 and 3 g of 1,1,2,2-tetramethyldiphenyldisilane were dissolved in 20 ml of xylene and filtered through a membrane filter having pores of 0.25 μm, It was used as a coating liquid.

After dehydration baking at 200 ° C. for 1 minute, SAL601ER7 (chemical amplification resist, Shipley Co., Ltd.) was spin-coated to 0.7 μm thickness on a 5-inch silicon wafer surface-treated with hexamethyldisilazane HMDS, and 90
Bake at 90 ° C for 90 seconds. On top of this, add the above coating solution to 0.4
It was spin-coated so as to have a film thickness of μm and dried at room temperature for 10 minutes to form a CEL layer.

The above is the NSR1505EX (manufactured by Nikon, which is a KrF excimer laser reduction projection exposure apparatus).
NA: 0.42) to expose a line-and-space pattern, and then perform PEB (post-exposure bake) at 110 ° C. for 90 seconds, using the MF622 developer which is a dedicated developer for the resist used. Developed for minutes.

Regarding the processing on this wafer under the above-mentioned conditions, the focus margin of 0.4 μm line and space was examined, and it was found to be 1.5 μm in the range. The proper exposure amount was 110 mJ / cm ² .

Comparative Example-1 The same treatment as in Example-1 was carried out except that the CEL layer was not applied, and the focus margin of 0.4 μm line and space was examined and found to be 1.0 μm. The proper exposure amount was 70 mJ / cm ² .

As is clear from the comparison with this comparative example, according to this example, the CEL layer can be formed by direct coating, and the KrF having a high resolution can be formed by a simple process capable of direct development. The CEL process in excimer lithography can be performed, and the focus margin is sufficient.

[0027]

The photobleaching / photobleaching organic material film according to the present invention is directly provided without an intermediate layer for preventing miscibility even when it is provided on a resist for improving contrast. It has an effect that it can be removed by direct development.

Then, the silicon-containing resist is converted into SiO ₂ in an O ₂ atmosphere by etching back as necessary. For example, O ₂ plasma treatment can be used. This allows
As shown in FIG. 1E, the upper layer 3 which is a well-planarized SiO ₂ interlayer film is also formed on the patterns 21, 22 and 23 having different widths formed on the substrate 1.

Example-2 This example is a modification of Example-1. In this embodiment,
1 (a) to 1 (d), the same steps as in Example-1 are performed.

After obtaining the structure of FIG. 1D, in this embodiment, etching is performed up to the patterns 21, 22, 23 having different widths. That is, here, the upper layer material layer 30 is removed by etching up to the aluminum wiring pattern. At the same time, the same width patterns 41 to 45 are also removed. As the etching means at this time, a means or the like used for usual etch back can be appropriately used.

In this embodiment, thereafter, the upper layer material (here, SiO ₂ ) is piled up as needed (for example, C
Various deposition means such as VD can be used), FIG.
A structure similar to that of (e) is obtained.

In the present embodiment, after the etching step for flattening (horizontal return etching etc.) as described above, etching is performed up to the patterns 21, 22 and 23 having different widths. Is a concrete form of. According to the third aspect of the invention, the same width pattern 4 is simultaneously formed.
1-45 are also removed by etching, and this portion does not contribute to the formation of the upper layer 3. Therefore, the same width patterns 41 to 4
5 does not necessarily have to be a silicon-containing resist,
It may be formed of any material.

Example-3 This example is also a modification of Example-1. In this embodiment, the same steps as those in Embodiment-1 are taken from FIGS. 1A to 1E. However, in this embodiment, the step of further stacking the upper layer material is performed from the state of FIG. 1E after etching and oxidation of the silicon-containing resist. The upper layer material to be stacked was SiO _{2 in} this example as well. However, a different material may be used.

Example-4 Next, Example-4 will be described with reference to FIGS. This example embodies the invention of claim 4,
Similar to Example-1, the present invention is used for manufacturing a miniaturized and integrated VLSI. In this embodiment, the upper layer 3 is formed on the patterns 21 to 23 of the substrate 1 having two or more patterns 21, 22 and 23 having different widths (see FIG. 2).
(F)), in a method of manufacturing a semiconductor device including a step of flattening the upper layer 3, etching stop layers 61 to 63 are formed on the patterns 21 to 23, and at least etching is used to flatten the upper layer 3. .

The patterns 21 to 23 in this embodiment are aluminum wiring layers, but here, the patterns 21 to 23 are formed.
In particular, 23 is a so-called barrier metal structure (particularly AI / Ti /, in which a titanium layer 2b and a titanium nitride layer 2c are formed from the aluminum layer 2a between a semiconductor silicon substrate which is the base substrate 1 and the aluminum layer 2a. T
iN structure).

Each step of this embodiment will be described in more detail as follows.

In this embodiment, first, the barrier metal / Al / LP-Si ₃ N ₄ is sequentially formed from the base substrate 1. As a result, specifically, as shown in FIG. 2A, a barrier metal structure forming layer including an aluminum layer 20a, a titanium layer 20b, and a titanium nitride (TiN) layer 20c, and a low-pressure silicon nitride layer thereon. A structure with 6 is obtained. This silicon nitride layer 6 will form an etching stop layer.

Specifically, for example, Ti / TiN / Al-
_{Si / LP-Si 3 N 4} = 300/700/3000 /
A structure with a film thickness of 500 (angstrom) is formed. A barrier metal, aluminum (or Al-Si alloy) layer may be used an ordinary sputtering, also, LP-Si ₃ N ₄ constituting the etching stop layer, using conventional LP-CVD furnace, for example a gas SiH as a system
It can be formed using a ₂ Cl ₂ / NH ₃ system gas.

The silicon nitride layer 6 may also serve as an antireflection film. In that case, the forming conditions are changed to control the thickness and the refractive index.

Next, after resist patterning, a desired wiring pattern is processed by dry etching or the like. As a result, the structure shown in FIG. 2B is obtained. That is, the base 1
Above each aluminum pattern 2a, titanium pattern 2
b, a structure having patterns 21 to 23 composed of titanium nitride pattern 2c and etching stop layers 61 to 63 formed on the patterns 21 to 23 is obtained.

Next, by using the bias ECR-CVD method, the space between the patterns 21 to 23 is filled under the following conditions, for example: Gas system used: SiH ₄ / N ₂ O = 20/35 SCCM Pressure: 7 × 10 ^-4 Torr RF bias: 500W Microwave: 800W Magnetic field: 875 gauss

As a result, the structure shown in FIG. 2C is obtained. That is, extra SiO ₂ 3c on the wide pattern 23
And extra SiO ₂ 3a on the narrow patterns 21 and 22,
The thickness of each extra portion is different from that of 3b.

Next, the etching and deposition conditions are adjusted so that neither etching nor deposition progresses in the vertical direction (vertical direction in the figure) and etching progresses in the horizontal direction (horizontal direction in the figure). Etching is performed to obtain a margin for resist alignment.

For example, etching is performed under the following conditions. Gas system used: SiH ₄ / N ₂ O = 7.5 / 35 SCCM Pressure: 7 × 10 ⁻⁴ Torr RF bias: 500 W Microwave: 800 W Magnetic field: 875 Gauss

As a result, the structure shown in FIG. 2D is obtained.
Special parts 3d to 3f for the removed parts by horizontal return etching
(Portion indicated by broken line).

Further, as shown in FIG. 2E, a resist is applied and patterned to obtain a resist pattern 7, and excess SiO ₂ is removed by wet etching or the like using this as a mask. For example, it is removed with hydrofluoric acid HF. At that time, LP-Si ₃ N ₄ is used as the etching stop layers 61 to 6
The aluminum pattern 2a in the patterns 21 to 23 is not etched because it functions as 3. The resist pattern 7 is removed at the same time or in a later step as appropriate.

Next, an interlayer film (here, a SiO ₂ film) is stacked up to a desired thickness. As a result, it is possible to obtain the structure in which the interlayer film which is the upper layer 3 shown in FIG. 2F is formed. The additional portion is indicated by reference numeral 32.

In this embodiment, at least one etching stop layer 61 to 63 is provided on the wiring patterns 21 to 23 in the process of flattening the upper layer 3 forming the interlayer film by the bias ECR-CVD method. Since the extra interlayer film portion is removed, the necessary pattern is not etched even when the extra film is removed. Moreover, in this example, the etching stop layers 61 to 6 are formed.
3 can also be used as an antireflection film of an aluminum pattern forming the wiring patterns 21 to 23.

In the above example, Ti / Ti is used as the barrier metal.
Although the N structure is adopted, the structure is not limited to this, and other elements such as Ti are used.
A / TiON structure or the like can be arbitrarily used.

Example-5 This example is a modification of Example-4. That is, Example-
In 4, the wiring pattern (patterns 21 to 23) is formed after the silicon nitride layer serving as an etching stopper is formed.
Patterning was performed, but in this example, patterns 21 to
After forming 23, a silicon nitride layer is formed and used as an etching stop layer. In the case of this example, the etching stop layer is attached to the entire surface. This example can also achieve the same effect as that of the example-4.

[0048]

According to the inventions of claims 1 to 3, the method of manufacturing a semiconductor device according to each invention of the present application solves the problems associated with the dependency of the underlying pattern on the planarization of the interlayer film and the like. According to the invention of claim 4, it is possible to achieve good planarization by eliminating the dependency of the planarization shape on the underlying pattern. Good planarization can be achieved without adverse effects.

[0049]

[Brief description of drawings]

1A to 1E are cross-sectional views showing the steps of Example-1.

2A to 2F are cross-sectional views showing the process of Example-2.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is a cross-sectional view showing a conventional example.

[0050]

[Explanation of symbols]

 1 Base (Substrate) 21-23 Patterns with Different Widths (Wiring Patterns) 3 Upper Layers (Interlayer Films) 41-45 Same-Width Patterns 61-63 Etching Stop Layers

[Procedure amendment]

[Submission date] January 6, 1994

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Delete

Claims (1)

[Claims] 1. An organic material film having a bleaching action or a fading action to light, wherein the organic material film uses at least a xylene-soluble resin as a binder and at least a disilane dye as a photobleaching / bleaching dye. An organic material film having a bleaching action or a fading action against light, which is characterized by being used.