KR100817914B1 - Polymer for forming anti-reflective coating layer and composition containing the same, and method for producing semiconductor device pattern using the same - Google Patents

Abstract

The present invention relates to a polymer or a composition including the same, which forms a silicon anti-reflective coating film having a relatively very slow etching speed and a thin thickness in forming an etched layer pattern of a semiconductor device. The formed film not only performs anti-reflective function but also can be used as a mask for etching a thick hard mask film. In addition, the present invention can form an organic hard mask film and a silicon anti-reflective film by a simple spin coating method and use it as a hard mask to etch a thick etching target layer with a thin photoresist film.

Description

Polymer for forming anti-reflective coating film, a composition comprising the same, and a method for forming a semiconductor device pattern using the same {{Polymer for forming anti-reflective coating layer and composition containing the same, and method for producing semiconductor device pattern using the same}

1 is an NMR spectrum of a polymer for forming a silicon-based antireflection film according to an embodiment of the present invention,

2A to 2F are cross-sectional views illustrating a method of forming a semiconductor device pattern according to the present invention using the composition for forming a silicon-based antireflection film including the polymer shown in FIG. 1,

3 is a cross-sectional view of an etched layer pattern formed by Example 3. FIG.

  ♠ Explanation of symbols on the main parts of the drawing ♠

200 semiconductor substrate 210 etched layer

220: organic hard mask film 230: silicon diffuse reflection prevention film

240: photoresist film

The present invention relates to a polymer for forming a silicon-based anti-reflective coating film, and more particularly, a mask used to etch a hard mask film used for preventing a pattern collapse phenomenon in an ultra-fine pattern forming process of a semiconductor device, and serves to prevent diffuse reflection. It relates to a polymer for forming a silicon-based antireflection film. In addition, the present invention also relates to a composition for forming a silicon-based antireflection film containing the polymer and a method of forming a semiconductor device pattern using the same.

In the semiconductor memory field, as the integration of memory increases, the implementation of resist line widths and line width stabilization in photolithography processes have become the most influential factors in the formation of semiconductor microcircuits. In particular, the exposure process is an important process that forms the basis for forming a semiconductor microcircuit, and is a process that greatly affects securing high resolution and improving the uniformity of the photoresist film pattern. Therefore, it is preferable to use short wavelength light in an exposure process in order to increase the resolution.

Recently, short wavelength light having a wavelength of 193 nm (ArF) is also used. When the ArF light is used, the limit resolution of the photoresist, that is, the limit resolution line width, is somewhat different depending on the exposure equipment, but is about 0.12 to 0.08 μm. However, if the wavelength of the exposure light is simply shortened to improve the resolution of the pattern, the optical interference effect is increased in the exposure process, and the pattern profile is poor or the size uniformity is degraded due to notching, standing wave, or the like. There is this.

Therefore, in order to suppress the occurrence of notching, standing waves, etc. due to the exposure light reflected from the etching target layer of the semiconductor substrate, a method of forming an antireflection prevention film for absorbing exposure light between the etching target layer and the photoresist film is commonly used.

In the past, the collapse of the pattern has been solved by lowering the thickness of the photoresist film. For example, when forming an ultrafine pattern of 70 nm or less, the thickness of the photoresist film should be lowered to 100 nm or less to prevent the collapse of the pattern. However, if the thickness of the photoresist film is lowered now, the lower layer (etched layer) of the photoresist film cannot be etched, so the thickness of the photoresist film can no longer be reduced. Therefore, in some cases, a hard mask film is formed under the photoresist film to prevent the pattern from collapsing during etching.

However, when using a hard mask film, the compositional relationship of the anti-reflective film is very important. That is, the diffuse reflection prevention film must satisfy the following basic conditions. First, there should be no phenomenon that the anti-reflection coating is dissolved and peeled off by the photoresist solvent when the process is applied. For this purpose, the antireflection film must have a crosslinked structure, and when forming the crosslinked structure, other impurities must not be generated by side reactions. Second, there should be no entry of chemicals such as acids and amines from the anti-reflective coating. Third, the antireflection film should have a relatively fast etching rate compared to the upper photoresist film. Thus, a smooth etching process may be performed using the photoresist layer as a mask during etching. Fourth, in order to improve the anti-reflection efficiency, the anti-reflection coating should be formed as thin as possible. Finally, the antireflection film should have a relatively slow etching speed compared to the underlying hard mask film. Thus, when etching, a thin anti-reflective film can be used as a mask to perform a smooth etching process on a thick hard mask film.

Accordingly, the present invention provides a polymer for forming a silicon-based anti-reflection prevention film and a composition comprising the same, which serves as a mask for etching a hard mask film used to prevent the collapse of a pattern in an ultra-fine pattern formation process of a semiconductor device, and serves to prevent diffuse reflection. Its purpose is to.

Another object of the present invention is to provide a method of forming a semiconductor device pattern in which an etched layer pattern of a semiconductor device is formed by using a pattern formed by the polymer or composition for forming a silicon-based antireflection film.

This invention for achieving the said objective uses the silicone type polyamic acid represented by following General formula (1) as a polymer for forming the diffuse reflection prevention film which absorbs the exposure light reflected by the etching target layer of a semiconductor substrate.

In addition, the present invention is a composition for forming a diffuse reflection prevention film that absorbs the light for exposure reflected from the etched layer of the semiconductor substrate, including a silicone-based polyamic acid, melamine derivatives, a thermal acid generator and an organic solvent represented by the formula (1) Configure.

In addition, the method of forming a semiconductor device pattern of the present invention includes the steps of forming an etched layer on top of a semiconductor substrate, forming an organic hardmask film on the etched layer, and a silicon-based antireflection film on the organic hardmask film. Forming a photoresist film, forming a photoresist film on the silicon anti-reflective coating, selectively exposing and developing the photoresist film, and forming a photoresist pattern, and using the photoresist pattern as an etching mask Etching sequentially to form an etched layer pattern.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the silicon-based antireflection film forming polymer according to the present invention, a composition comprising the same, and a method of forming a semiconductor device pattern using the same.

The polymer for forming a silicon-based antireflection film according to the present invention may be composed of a silicone-based polyamic acid. Silicone-based polyamic acid is obtained by the reaction of aminopropyl terminated polydimethylsiloxane and dihydride (dianhydride) in a conventional manner in a solvent, preferably the aminopropyl terminated poly By using dimethylsiloxane (aminopropyl terminated polydimethylsiloxane) and 4,4'-oxydiphthalic anhydride (4,4'-oxydiphthalic anhydride) of formula 3 in the dimethylacetamide solvent, It is preferable.

In addition, the present invention provides a composition for forming a silicon-based anti-reflective coating film comprising a silicone-based polyamic acid (polymer for forming a silicone-based antireflection film), a melamine derivative, a thermal acid generator and an organic solvent.

At this time, it is preferable to add 2,4,6-tris (dimethoxymethyl amino) -1,3,5-triazine of the following formula (4) as the melamine derivative, and the amount of the melamine derivative is added to the silicone-based polyamic acid of the formula (1). It is preferable that it is 2-20 weight part with respect to. If it is less than 2 parts by weight, a sufficient crosslinking reaction does not occur, and if it exceeds 20 parts by weight, the relative content of silicon decreases, so that the selectivity to the organic hard mask layer located in the lower layer is reduced, so that etching is impossible.

And as a thermal acid generator, it is preferable to add 2-hydroxycyclohexanyl paratoluenesulfonate of following formula (5), The addition amount is 2-20 weight part with respect to the silicone type polyamic acid of the formula (1). If it is less than 2 parts by weight, a sufficient crosslinking reaction does not occur, and if it exceeds 20 parts by weight, the relative content of silicon decreases, so that the selectivity to the organic hard mask layer located in the lower layer is reduced, so that etching is impossible.

In addition, cyclohexanol is preferably added as the organic solvent, and the amount thereof is preferably 400 to 6,000 parts by weight based on the silicone-based polyamic acid of the general formula (1). This is because the amount of solvent is determined according to the thickness of the desired film.

Next, a method of forming a semiconductor device pattern using the composition for forming a silicon-based antireflection film will be described with reference to the accompanying drawings. The semiconductor device pattern of the present invention includes circuit patterns such as various display devices such as semiconductor devices, liquid crystal display devices, and organic electroluminescent devices, and also includes devices having physical structures such as insulating films used in the devices.

2A to 2F are cross-sectional views illustrating a method of forming a semiconductor device pattern according to the present invention using the above-described composition for forming a silicon anti-reflective coating.

As shown in FIG. 2A, first, an etched layer 210, an organic hard mask film 220, a silicon anti-reflective film 230, and a photoresist film 240 are sequentially formed on the semiconductor substrate 200. At this time, the organic hard mask film 220 is formed to a thickness of 100 ~ 800nm using a spin coating equipment, the silicon anti-reflective film 230 is also formed to a thickness of 20 ~ 200nm using a spin coating equipment, a photoresist The film 240 is formed to a thickness of 40 to 200 nm.

Next, as shown in FIG. 2B, the photoresist film 240 is selectively exposed and developed to form a pattern of the photoresist film 240. As shown in FIG. 2C, the silicon anti-reflective coating 230 is etched using a conventional etching process using the pattern of the photoresist film 240 as an etching mask to form the silicon anti-reflective coating 230.

As shown in FIG. 2D, the organic hardmask film 220 is etched using the etching process using the conventional etching process using the silicon antireflective film 230 as an etch mask to form a pattern of the organic hardmask film 220. . Thereafter, as shown in FIG. 2E, the pattern of the organic hard mask layer 220 is used as an etching mask to etch the lower etching layer 210 using a conventional etching process to form a pattern of the etching layer 210.

Finally, as shown in FIG. 2F, the remaining material except for the etched layer 210 is cleaned and removed to complete the process of forming a semiconductor device pattern.

The organic hard mask film 220 of the present invention has the same properties as an organic material, and exhibits a sufficient selectivity when etching the inorganic material constituting the underlying etching layer 210, and can be coated thickly. The furnace can be used. The present invention coats and bakes a composition for forming a silicon-based antireflection film according to the present invention on the organic hard mask film 220 by spin coating to obtain a silicon-based anti-reflection film 230. At this time, the silicon-based diffuse reflection prevention film 230 may be formed by coating and baking a silicon-based polyamic acid of the polymer of the formula (1) by a spin coating method.

Since the silicon constituting the silicon-based antireflection film 230 has a sufficient selection ratio with respect to the organic hard mask film 220 below, the silicon-based anti-reflection film 230 may have a thick organic hard mask film 220. Etching is possible. After two etching processes, a pattern of an organic hard mask layer 220 having a thick thickness may be obtained, and a desired lower layer may be etched therefrom.

As described above, in the present invention, in forming the pattern of the etched layer 210, the organic hard mask layer 220 and the silicon anti-reflective layer 230 may be formed using a simple spin coating method. In this case, since the silicon-based anti-reflective film 230 is very transparent enough to be able to transmit to 633 nm, even if the organic hard mask film 220 is thickly coated to 400 nm or more, an alignment layer may be solved.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are merely to illustrate this invention and the present invention is not limited by the following examples.

Example 1 Preparation of Polymer for Forming Silicon-Base Anti-reflective Film

50 g of aminopropyl-terminated polydimethylsiloxane having a weight average molecular weight of 1,600 and 10 g of 4,4'-oxydiphthalian hydride of Formula 3 were dissolved in 400 g of tetrahydrofuran and reacted for 24 hours.

After completion of the reaction, precipitation was performed in normal hexane, and the precipitate was again washed with normal hexane several times and dried to obtain a silicone-based polyamic acid of Chemical Formula 1 according to the present invention. 1 shows an NMR spectrum of a silicon-based polyamic acid (polymer for forming a silicon-based antireflection film) of Chemical Formula 1. FIG.

Example 2 Preparation of Composition for Organic Hard Mask Film Formation

10 g of novolac resin having a weight average molecular weight of 8,000, 3 g of polyvinylphenol resin having a weight average molecular weight of 8,000, 2,4,6-tris (dimethoxymethyl amino) -1,3,5-triazine 1 g of formula (4), 2- 1 g of hydroxycyclohexanyl paratoluenesulfonate was dissolved in 130 g of a propylene glycol methyl ether acetate (PGMEA) solvent to prepare an organic hard mask film-forming composition according to the present invention.

Example 3 silicon-based antireflection film formation and etching layer pattern formation

A silicon oxide film (etched layer) was formed on the silicon wafer to a thickness of 400 nm, and then the composition for forming an organic hard mask film prepared in Example 2 was coated on the etching layer by a spin coating method. After coating and baking at 200 ° C. for 2 minutes to form an organic hard mask film having a thickness of 300 nm, a silicon anti-reflective coating film prepared in Example 1 was formed on the organic hard mask film to a thickness of 90 nm.

Then, after coating the Shin-Etsu (shinetsu) ArF photoresist composition on top of the silicon-based anti-reflective film, it was baked for 90 seconds at 130 ℃ to form a 200 nm thick photoresist film. After the exposure using the ArF exposure equipment, the wafer was baked at 130 ° C. for 90 seconds. After baking was completed, the resultant was developed in a 2.38 parts by weight tetramethylammonium hydroxide aqueous solution for 40 seconds to obtain a photoresist film pattern.

The silicon antireflective coating layer was selectively etched using the photoresist film pattern as an etching mask to form a silicon antireflective coating pattern. In addition, an organic hard mask layer pattern is selectively etched by using a silicon anti-reflective coating pattern as an etch mask to form an organic hard mask layer pattern. Finally, a lower etching layer is etched by using an organic hard mask layer as an etch mask. An etched layer pattern was formed.

3 is a cross-sectional view of an etched layer pattern formed by Example 3. FIG.

The present invention can be used as a mask for etching a hard mask film having a thick thickness as well as performing an antireflection function by using a polymer or a composition which forms a silicon-based antireflection film having a very slow etching speed and a thin thickness compared to a hard mask film. .

In addition, in the present invention, an organic hard mask film and a silicon anti-reflective film are formed by a simple spin coating method for forming an etched layer pattern of a semiconductor device and used as a hard mask to form a thick etched layer using a thin photoresist film. It can be etched.

In the above description, the technical details of the silicon-based anti-reflective coating film forming composition of the present invention, a composition comprising the same, and a method of forming a semiconductor device pattern using the same are described together with the accompanying drawings, which are illustrative examples of the best embodiments of the present invention. It does not limit this invention.

It is also apparent that any person skilled in the art can make various modifications and imitations within the scope of the appended claims without departing from the scope of the technical idea of the present invention.

Claims (11)

A polymer for forming a diffuse reflection prevention film that absorbs light for exposure reflected from an etched layer of a semiconductor substrate, Polymer for forming a silicon-based diffuse reflection prevention film, characterized in that it comprises a represented by the formula:

Wherein n and m represent the number of repeating units. A composition for forming a diffuse reflection prevention film that absorbs light for exposure reflected from an etched layer of a semiconductor substrate, A composition for forming a silicon-based anti-reflective coating film comprising a silicone-based polyamic acid, a melamine derivative, a thermal acid generator, and an organic solvent represented by the following chemical formula:

Wherein n and m represent the number of repeating units. The method according to claim 2, The melamine derivative is a composition for forming a silicon-based anti-reflective film, characterized in that 2 to 20 parts by weight based on the silicone-based polyamic acid. The method according to claim 2 or 3, The thermal acid generator is a composition for forming a silicon-based anti-reflective film, characterized in that 2 to 20 parts by weight based on the silicon-based polyamic acid. The method according to claim 2 or 3, The organic solvent is a silicon-based anti-reflective coating film composition, characterized in that added to 400 to 6,000 parts by weight based on the silicone-based polyamic acid. Forming an etched layer on top of the semiconductor substrate, Forming an organic hard mask layer on the etched layer; Forming a silicon type anti-reflective film by applying the composition of claim 2 on the organic hard mask film; Forming a photoresist film on the silicon anti-reflection film; Selectively exposing and developing the photoresist film to form a photoresist film pattern, and And etching the lower layers sequentially using the photoresist layer pattern as an etch mask to form an etched layer pattern. delete delete The method according to claim 6, The silicon anti-reflective film is formed in a thickness of 20 to 200nm method of forming a semiconductor device pattern. The method according to claim 6, The organic hard mask film is a method of forming a semiconductor device pattern, characterized in that formed in a thickness of 100 to 800nm. The method according to claim 6, The photoresist film is a semiconductor device pattern forming method, characterized in that formed to a thickness of 40 to 200nm.

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