JPS6338933A - Photosensitive and/or radiation sensitive composition and pattern forming method with said composition - Google Patents

Abstract

PURPOSE:To enable accurate and fine patterning with high resolution by using a compsn. contg. a specified organosilane compd. and a halide capable of producing a radical on being irradiated with light and/or radiation. CONSTITUTION:This photosensitive and/or radiation sensitive compsn. contains an organosilane compd. having repeating units represented by general formula I and a halide capable of producing a radical on being irradiated with light and/or radiation. In the formula I, each of R<1>-R<4> is methyl, ethyl, phenyl, biphenyl, phenylamino, phenoxy, benzyl, cyano, vinyl, acetoxy, t-butyl, H or halogen but all of R<1>-R<4> are not H and/or halogen, and n is an integer of 5-500. When the compsn. is used, a pattern can be accurately formed with high resolution.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for applying lithography using light or radiation.
The present invention relates to a composition suitable for forming precise and fine patterns made of thin films with good resolution and high precision, and a method for forming fine patterns using the composition.

[Conventional technology]

Conventionally, a method of forming a pattern consisting of a thin film by lithography using light or radiation is to expose a single layer resist film made of novolac resin, chloromethylated polystyrene, polymethyl methacrylate, etc. to pattern light, and then develop it. A developing method using a liquid has been widely used.

However, in recent years in the field of semiconductor integrated circuits.

With the development of more highly integrated circuits such as ILsI, finer pattern forming technology is required. When the resist film is developed, the resist film swells, preventing the formation of fine patterns, or if the substrate on which the resist film is laminated has a step, etc., the reflection of the irradiated light on the substrate surface may occur. There are problems in that the resolution is extremely reduced due to scattering and scattering, and it has not been possible to support the formation of finer patterns with good resolution.

Therefore, as a method for forming finer patterns with good resolution, for example, an organic polymer is used as the lower layer, and a
A so-called three-layer resist process in which a conventional photosensitive resist is formed on the upper layer of an inorganic compound such as i02 or Ge, the upper layer is exposed, developed and patterned, and the pattern is sequentially transferred to the lower layer by dry etching using this as a mask. etc. have been developed, but the number of steps has increased significantly, and there are still difficulties in terms of productivity and production costs.

[Problem that the invention seeks to solve]

The present invention was made in view of the above-mentioned problems, and its purpose is to provide a photosensitive material suitable for forming precise and fine patterns made of thin films with high resolution and high precision by lithography using light or radiation. An object of the present invention is to provide a composition having radiation sensitivity and/or radiation sensitivity, and a method for forming a fine pattern using the composition.

Another object of the present invention is to develop resists used in precision micro-etching processes necessary for forming solid materials with fine P' microfabrication used in highly integrated devices such as ultra-LSIs. The object of the present invention is to provide a composition having photosensitivity and/or radiation sensitivity suitable for forming a film.

[Means for solving problems]

The above object can be achieved by the following invention.

The present invention is characterized by containing an organosilane compound having a moiety represented by the following general formula (I) and a halide capable of generating radicals when exposed to light and/or radiation. Alternatively, a first layer consisting of a radiation-sensitive composition and a material that can be etched by oxygen plasma etching is laminated on the substrate, and a portion represented by the following general formula (I) is further formed on the first layer. and a halide that can generate radicals when exposed to light and/or radiation; After exposing the pattern by irradiation with radiation, developing the laminated layer and removing the exposed portion of the laminated layer from the substrate to form a pattern consisting of the second layer; a pattern consisting of the second layer; A method of forming a pattern is characterized in that it includes the step of etching the first layer with oxygen plasma using the first layer as a resist pattern.

(In the above formula, R1, R2, R3 and R4 are respectively methyl group, ethyl group, phenyl group, biphenyl group, phenylamino group, phenoxy group, benzyl group, cyano group, vinyl group, acetoxy group, t-butyl group, Represents either a hydrogen atom or a halogen atom, provided that Ht, Rz, R
3 and R4 are all hydrogen atoms and/or halogen atoms, and n is an integer from 5 to 500.

) That is, the photosensitive and/or radiation-sensitive composition of the present invention basically contains one or more halides capable of generating an organosilanated radical having the moiety represented by -formation CI) above. It has the property that its solubility in a developer changes as exemplified later by being irradiated with light and/or radiation depending on the type of halide contained, and due to this difference in solubility. This allows patterning.

Moreover, this change in solubility is highly sensitive to irradiation, and high resolution can be obtained during pattern exposure.

Therefore, photosensitivity or radiation sensitivity as used in the present invention refers to irradiation with light or radiation.

It refers to the characteristic that the solubility in the developer changes.

The organosilane compound having the moiety represented by the above-mentioned -formation (I) used in the photosensitive and/or radiation-sensitive composition of the present invention can be developed by radicals generated from a halide as described later. It has the property of increasing its solubility in liquids (positive type), and when mixed with halides, it can form thin films with good film-forming properties that can withstand more precise and fine processing, and it can be processed with developing solutions. Unlike conventional resists, it does not cause swelling.

Furthermore, a thin film composed of this organosilane compound in a mixed state with a halide, which will be described later, has excellent resistance to plasma used in dry etching, for example, and has a relatively high glass transition temperature, so it can withstand the high heat applied in the plasma etching process. It has the advantage that it is less susceptible to softening due to etching and is stable during etching operations, and is also suitable for use in resist pattern formation in pattern formation by plasma etching.

In the organosilane compound used in the present invention, examples of the repeating unit of the moiety represented by the above-mentioned -formation (I) include, for example, those having the following structure.

The halide contained in the composition having photosensitivity and/or radiation sensitivity of the present invention is suitable for light, e.g.
It has the function of generating radicals upon receiving radiation such as radiation, ion beams, far ultraviolet rays, etc., and changing (increasing) the solubility of an organosilane compound having a moiety represented by -formation CI) in a developer, Any such material can be used. Specifically, the halides that can be used in the present invention include carbon tetrabromide, carbon tetraiodide, methane iodide, tribromphenyl sulfone, α, α, α-tribromoacetophenone, α-bromo- α-cyano-p-nitrotoluene and the like can be mentioned. One or more of these halides can be used in combination as desired.

The photosensitive and/or radiation-sensitive composition of the present invention can be obtained by mixing one or more of the organosilane compounds and one or more halides as desired, for example, If a halide that generates radicals when exposed to light is used, the composition of the present invention will be photosensitive, and if a halide that generates radicals when exposed to radiation is used, the composition of the present invention will be radiation sensitive. If used together, it will have the characteristics of both.

The content of the halide may be determined depending on the type thereof and the sensitivity of the desired composition to light and radiation, but for example, in order to perform more precise and fine processing with good resolution, 1 for organosilane compounds
It is preferably about 0 to 200% by weight.

As a developing solution for a composition having photosensitivity and/or radiation sensitivity of Kiwamon, as described above, it is possible to effectively bring out the difference in solubility between the exposed area and the unexposed area after exposure, and to remove the lower layer. Any material can be used as long as it does not affect the (first layer); for example, methanol, ethanol, isopropyl alcohol, acetone,
Preferred examples include methyl ethyl ketone, ethylce, and solve.

Note that the composition having photosensitivity and/or radiation sensitivity of the present invention is used in the form of a solution. Alternatively, when coating on a suitable substrate to form a dry film, the organosilane compound and the halide may be dissolved or dispersed in a suitable solvent and mixed to form a solution.

As a solvent for forming this solution-like composition, toluene, xylene, hexane, trichloroethylene, etc. can be used.

The solution-like composition thus formed is laminated onto a desired substrate by various coating methods, spraying methods, dipping methods, printing methods, etc., and is then dried under appropriate conditions. It can be made into a dry film.

As mentioned above, the photosensitive and/or radiation-sensitive composition of the present invention is suitable as a resist used in a pattern forming method using plasma dry etching.
For example, it can be used in the pattern forming method of the present invention as described below.

Hereinafter, the pattern forming method of the present invention will be explained in detail using the drawings.

1 to 5 are process diagrams showing the main steps of the method of the present invention.

In the method of the present invention, first, as shown in FIG.
On a suitable substrate 3 made of, for example, silicon, quartz, glass, etc., a first layer is etched, which can be etched, for example, by oxygen plasma.
Layer 1 is formed.

This first layer may be made of, for example, polymethyl methacrylate,
Polyimide, AZ-1350 (trade name, manufactured by Sibley)
It can be formed from etc.

Next, as shown in FIG. 2, a second layer comprising the photosensitive and/or radiation-sensitive composition of the present invention is placed on the first layer 1.
Layer 2 is laminated. The dry film forming method described above may be applied to this lamination step.

Here, pattern exposure is performed on the second layer 2 according to a desired pattern. Depending on the photosensitivity and radiation sensitivity of the composition of the present invention forming the second layer 2, the pattern exposure method may include light, radiation, or both.
A method of irradiating through an exposure mask according to a desired pattern, a method of scanning these irradiation beams over the second layer 2 according to a desired pattern, etc. can be applied.

By such pattern exposure, exposed areas 4 and unexposed areas 5 as shown in FIG. 3 are formed.

Next, the second layer 2 is treated with a developer under appropriate processing conditions using a method such as a dipping method or a spray method. Then, the exposure section 4 is removed from the substrate 3, and the second exposure section 4 is removed as shown in FIG.
A pattern consisting of unexposed portions 5 of layer 2 is formed.

Since the composition used for the second layer has the above-mentioned characteristics, the pattern formed here is fine and has high precision in terms of resolution.

Finally, the surface of the substrate 3 in this state on which the layers 1 and 2 are provided is subjected to oxygen plasma etching such as RIE (reactive ion etching) using oxygen gas which may contain hydrogen as required. When the etching process is performed, the core layer is precisely etched from the portion of the first layer 1 that was exposed when the second layer 2 is removed, and is removed from the substrate, as shown in FIG. second layer 2
It is possible to obtain a first layer 1 that exactly corresponds to the pattern 5, and a pattern consisting of these two layers can be formed.

Note that as the substrate 3, for example, CF4. CCV a, CCI 2 F2,
NF3, SF, etc. (may further contain hydrogen)
If the material is made of a material that can be etched by halogen plasma etching using
Using the pattern consisting of the second layer 2 and the second layer 2 as a resist pattern, it is possible to perform fine processing by etching the substrate 3. For example, it is possible to finely process the substrate 3 using a solid material used for more highly integrated elements such as VLSI. Suitable for precision micromachining.

Moreover, by forming a resist pattern with such a two-layer structure, that is, the resist layer directly related to pattern exposure is not directly laminated on the substrate. When a resist related to direct pattern exposure is formed as a layer, it is possible to reduce the influence of the exposure light on the substrate surface, such as reflection of the exposure light on the substrate surface and scattering when there is a step or unevenness. Furthermore, as mentioned above, the second layer 2 on top of the resist pattern has excellent resistance to plasma and is stable during processing operations, thus preventing the occurrence of defective etching points due to deformation or damage of the resist pattern. can.

〔Example〕

The present invention will be explained in more detail below with reference to Examples.

Example 1 First, PIQ liquid (trade name, polyimide precursor, manufactured by Hitachi Chemical Co., Ltd.) was coated with lμ on a substrate made of a silicon wafer provided with a 0.5 μs thick oxide film by spin coating.
After applying it to a thickness of
A polyimide film was formed.

Next, on this polyimide film, a solution of 30 mg of polysilastyrene (molecular weight 30,000) and 30 g of carbon tetrabromide dissolved and mixed in 1 wt of trichlene was added until the dry film thickness was 0.
．． It was applied in two coats and allowed to dry.

Here, deep ultraviolet light was applied to the formed thin film using PLA520.
By using K (trade name, manufactured by Canon Inc.), irradiation was performed for 25 seconds in a pattern corresponding to a line and space pattern with a width of 0.5 uI.

At the end of the irradiation process, the thin film was developed with ethanol.

Next, the thin film forming surface of the substrate was coated with an RIE device using oxygen gas at a gas pressure of 2 Pa and an applied power density of 0.1 W/Cl1.
When the etching process was carried out under 12 operating conditions, a 0.5-width line-and-space pattern with a film thickness of 1 mm could be formed with high accuracy and resolution.

Furthermore, the pattern forming surface of the substrate was coated with CF4. RIE device using H2 gas, gas pressure 5 Pa, applied power density 0
．． When etching was performed under operating conditions of 2 W/cm2.10 minutes, the oxide film on the substrate surface was patterned with high precision in a shape that corresponded exactly to the pattern.

Example 2 First, Example 1 except that the PIQ liquid was applied to a thickness of 1.5 scales.
A polyimide film was formed on a substrate made of a silicon wafer provided with an oxide film in the same manner as above.

Next, on this polyimide film, a solution of 3 layers of polysilastyrene (molecular weight 30,000) g and α,α,α-tribromoacetophenone 25+ag dissolved and mixed in 1:1 of trichlene was added so that the dry film thickness was 0.2 μs. Apply to
Dry.

Here, the formed thin film was exposed to X-rays (PdLa rays) at 280°C.
Irradiation was performed at mJ/c+a2 in a pattern corresponding to a line and space pattern with a width of 0.5 μs.

At the end of the irradiation process, the thin film was developed with ethanol.

Next, the fiI film forming surface of the substrate was subjected to RI using oxygen gas.
E equipment, gas pressure IPa, applied power density 0.1W/c
When the etching process was carried out under operating conditions of rn2.12 minutes, a line and space pattern of 1.5-thickness and 0.5-width could be formed with good precision and resolution.

Example 3 On a substrate made of a silicon wafer similar to that used in Example 1, polymethyl methacrylate (PMMA) was applied by spin coating to a thickness of 1 tile 1.7', +7
) A PMMA film was formed by baking at 200° C. for 1 hour.

Next, polymethylphenylsilane (
10000 molecules) 50mg and carbon tetraiodide 40
The solution was applied in an amount of 0.2 mg to 9 kg of pheasant and dried.

Here, a pattern corresponding to a 0.5-width line-and-space pattern was drawn on the formed thin film using an electron beam drawing device (Elionix Co., Ltd., ELS-330U), and then the thin film was developed with ethanol.

Next, the thin film forming surface of the substrate was coated with an RIE device using oxygen gas at a gas pressure of 0.5 Pa. Applied power density 0.15W/
ca+2. When etching was performed under operating conditions of 12 minutes, the film thickness was 0.25. A wide line-and-space pattern could be formed with high accuracy and resolution.

〔Effect of the invention〕

The photosensitive and/or radiation-sensitive composition of the present invention is composed of a combination of an organosilane compound having the moiety represented by -formation (I) and a norogenide, and is resistant to light and radiation. Radicals are efficiently generated from the halide by irradiation, and these act effectively on the composition, making it possible to perform more precise and fine patterning with good resolution. Moreover, unlike conventional resists, the resist does not swell even when treated with a developer.

In addition, the thin film made of this composition has excellent resistance to the plasma used in dry etching, and has the advantage of being stable and less susceptible to softening due to the high heat applied during the plasma etching process because its glass transition temperature is relatively high. It is also suitable for use as a resist pattern in pattern formation by plasma etching.

Further, on the plasma-etchable substrate, a lower layer made of a material that can be etched by plasma etching;
By using the composition of the present invention as a two-layer resist consisting of an upper layer, that is, since the resist layer directly involved in pattern exposure is not directly laminated on the substrate, it can be used as a two-layer resist, for example, as in the case of using a one-layer resist. When a layer of resist for direct pattern exposure is applied to the substrate, it reduces the effects of the exposure light on the substrate surface, such as reflection of the exposure light on the substrate surface and scattering when there are steps or unevenness, resulting in higher resolution. High precision IE fine patterning can be performed on the substrate. Moreover, the 2
The second layer 2, which is the upper layer of the resist pattern in the layered structure, has excellent resistance to plasma and is stable during processing operations, so that it is possible to prevent the occurrence of defective etching points on the substrate due to deformation or damage of the resist pattern.

[Brief explanation of drawings]

1 to 5 are process diagrams showing the main steps of the pattern forming method of the present invention. 1: First layer 2: Second layer 3: Substrate 4: 5 exposed areas Unexposed area Patent applicant: Canon Co., Ltd. Representative Tadashi Wakabayashi Figure 1 Figure 3 Figure 5 Figure 2 Figure 4 figure

Claims (1)

[Scope of Claims] 1) It is characterized by containing an organosilane compound having a moiety represented by the following general formula (I) and a halide capable of generating radicals when exposed to light and/or radiation. A composition having photosensitivity and/or radiation sensitivity. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the above formula, R^1, R^2, R^3 and R^4 are respectively methyl group, ethyl group, phenyl group, biphenyl group,
Represents any one of a phenylamino group, a phenoxy group, a benzyl group, a cyano group, a vinyl group, an acetoxy group, a t-butyl group, a hydrogen atom, and a halogen atom. However, R^1
, except that R^2, R^3 and R^4 are all hydrogen atoms and/or halogen atoms, and n is 5 to 50
It is an integer of 0. )2) Laminating a first layer made of a material that can be etched by oxygen plasma etching on a substrate, further comprising an organosilane compound having a moiety represented by the following general formula (I) on the first layer; laminating a second layer made of a composition containing a halide capable of generating radicals when exposed to light and/or radiation;
After exposing the second layer to a pattern by irradiating light and/or radiation, the layer is developed and the exposed portion of the layer is removed from the substrate to form a pattern made of the second layer. A method for forming a pattern, comprising the steps of: using the pattern made of the second layer as a resist pattern, and etching the first layer with oxygen plasma. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the above formula, R^1, R^2, R^3 and R^4 are respectively methyl group, ethyl group, phenyl group, biphenyl group,
Represents any one of a phenylamino group, a phenoxy group, a benzyl group, a cyano group, a vinyl group, an acetoxy group, a t-butyl group, a hydrogen atom, and a halogen atom. However, R^1
, R^2, R^3 and R^4 are all hydrogen atoms and/or halogen atoms. Also, n is 5 to 50
It is an integer of 0. )3) The substrate is made of a material that can be etched by halogen plasma etching, and after the pattern consisting of the first layer and the second layer is formed, the substrate is further etched with halogen plasma using the pattern as a resist pattern. A method for forming a pattern according to claim 2, which comprises plasma etching.