KR20110043994A - Filler for semiconductor capacitor and method for manufacturing semiconductor capacitor using the same - Google Patents

Abstract

PURPOSE: A filler for a semiconductor capacitor and method for manufacturing a semiconductor capacitor using the same are provided to convert a silicon based compound with a t-butyloxycarbonyl group into a carboxyl group by a heating process, thereby increasing development performance. CONSTITUTION: A conductive layer is formed on the semiconductor substrate(1). A filling layer is formed by coating the conductive layer with filler. A part of the conductive layer is eliminated to form a first electrode(5a). A dielectric layer(9) is formed on the first electrode. A second electrode(11) is formed on the dielectric layer.

Description

Filler for semiconductor capacitor and manufacturing method of semiconductor capacitor using said filler {FILLER FOR SEMICONDUCTOR CAPACITOR AND METHOD FOR MANUFACTURING SEMICONDUCTOR CAPACITOR USING THE SAME}

The present invention relates to a filler for semiconductor capacitors and a method for producing a semiconductor capacitor using the filler.

As semiconductor technology develops, research on high density and high speed semiconductor memory cells with higher integration density and improved performance in smaller size semiconductor chips continues. In particular, dynamic random access memory (DRAM), which can freely input and output information and can be implemented in a large capacity, is widely used among semiconductor memory cells.

The DRAM includes a plurality of unit cells including one MOS transistor and one capacitor. Among them, the capacitor includes two electrodes and a dielectric layer positioned therebetween, and the capacitance of the capacitor may be determined according to the dielectric constant, the thickness of the dielectric layer, and the area of the electrode forming the capacitor.

On the other hand, as the size of the semiconductor chip gradually decreases, the size of the capacitor also decreases, and accordingly, a capacitor capable of sufficiently securing the storage capacity is required. In order to implement such a capacitor, there is a method of increasing the overall effective area of the capacitor by increasing the vertical area instead of decreasing the horizontal area of the capacitor. In the case of forming the capacitor in this manner, a filler filling the mold and the formed gap for the mold may be used to effectively form electrodes having a relatively high height as compared to a narrow horizontal area.

One embodiment of the present invention provides a filler for gap fill of a semiconductor capacitor having excellent fillability and flatness and improved developability and storage stability.

Another embodiment of the present invention provides a method of manufacturing a semiconductor capacitor using the filler.

Filler for a semiconductor capacitor according to an embodiment of the present invention has a tertiary alkyloxycarbonyl group (tertiary alkyloxycarbonyl) represented by the formula (1) at the end.

[Formula 1]

In Formula 1, R ₁ to R ₃ are the same as or different from each other, and C1 to C3 are substituted or unsubstituted alkyl groups.

The tertiary alkyloxycarbonyl group may include a t-butyloxycarbonyl group (t-butyloxycarbonyl).

The silicone-based polymer may be represented by Chemical Formula 2.

[Formula 2]

_{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m

In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ CR ₁ R ₂ R ₃ , x is an integer from 1 to 6, R ₁ R ₃ is as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000.

The silicone-based polymer may be represented by Chemical Formula 3.

(3)

_{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m

In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 The alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m may be 12 to 2,000.

The filler for the semiconductor capacitor may further include a thermal acid generator and a solvent.

The silicone-based polymer, the thermal acid generator and the solvent may be included in amounts of 1 to 50% by weight, 0.01 to 25% by weight and the balance, respectively, based on the total content of the filler. According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor capacitor, the method including forming a mold having a gap on a semiconductor substrate, forming a conductive layer on the semiconductor substrate and the mold, on the gap and the conductive layer. Applying a filler to form a filling layer, heat treating the filling layer, developing a portion of the filling layer to form a filling pattern filled in the gap, and removing a portion of the conductive layer to form a plurality of first layers Separating into an electrode, removing the mold and the charging pattern, forming a dielectric layer on the first electrode, and forming a second electrode on the dielectric layer, wherein the filler is formula (1) at the end; It may include a silicone-based polymer having a tertiary alkyloxycarbonyl group represented by.

[Formula 1]

In Formula 1, R ₁ to R ₃ may be the same as or different from each other, and may be a substituted or unsubstituted alkyl group of C1 to C3.

The tertiary alkyloxycarbonyl group may include a t-butyloxycarbonyl group (t-butyloxycarbonyl).

The silicone-based polymer may be represented by Chemical Formula 2.

[Formula 2]

_{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m

In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a C6 to C20 Substituted or unsubstituted aryl group, n is an integer of 0 to 2, m may be 12 to 2,000.

The silicone-based polymer may be represented by Chemical Formula 3.

(3)

_{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m

In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 The alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m may be 12 to 2,000.

The filler further includes a thermal acid generator and a solvent, wherein the silicone-based polymer, the thermal acid generator and the solvent may be included in an amount of 1 to 50% by weight, 0.01 to 25% by weight and the balance based on the total content of the filler. .

The heat treatment of the packed layer may be performed at 160 to 240 ° C.

Removing the mold and the filling pattern may use a fluorine-containing solution.

The filler according to the embodiment of the present invention has excellent storage stability at room temperature, so that even if stored for a long time, the molecular weight does not change significantly, thereby increasing process reliability and improving developability by a predetermined heat treatment. In addition, it has excellent fillability to a gap having a high aspect ratio, so that it can be filled well even in fine gaps, and can be filled uniformly and densely without air voids or gaps, and also has excellent flatness of the film surface.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Unless otherwise defined herein, 'substituted' means that a hydrogen atom in a compound is a halogen atom (F, Br, Cl, or I), a hydroxyl group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amino group Dino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group, alkenyl group of C2 to C16, C2 to C16 alkynyl group, aryl group, C7 to C13 arylalkyl group, C1 to C4 oxyalkyl group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C15 C15 is substituted with a substituent selected from a cycloalkynyl group, a heterocycloalkyl group, and a combination thereof.

In addition, unless otherwise defined herein, "hetero" means containing 1 to 3 heteroatoms selected from N, O, S and P.

Hereinafter, a filler for a semiconductor capacitor according to an embodiment of the present invention will be described.

Filler according to an embodiment of the present invention comprises a silicone-based polymer, the silicone-based polymer has a tertiary alkyl oxycarbonyl (tertiary alkyl oxycarbonyl) at the end.

The tertiary alkyloxycarbonyl group may be represented by Formula 1:

[Formula 1]

Wherein R ₁ to R ₃ are the same as or different from each other, and are selected from alkyl groups of C1 to C3.

Among these, the tertiary alkyloxycarbonyl group is R ₁ To R ₃ may be a t-butyloxycarbonyl group in which a methyl group (t-butyloxycarbonyl).

Tertiary alkyloxycarbonyl groups can be introduced at the ends of the silicone-based polymer to act as protecting groups to reduce the reactivity of the silicone-based polymer. Accordingly, the silicone polymer can be easily reacted at room temperature to prevent the characteristics such as molecular weight from changing, thereby exhibiting excellent storage stability.

This causes problems such as slow self-condensation between hydroxy groups at room temperature when the reactor has a reactor such as hydroxy group (-OH) at the end of the silicone-based polymer, which increases the molecular weight of the polymer and impairs storage stability. It can be eliminated, and even after long-term storage at room temperature, the molecular weight does not change significantly, and process reliability can be attained.

In addition, the tertiary alkyloxycarbonyl group may be converted to a carboxyl group as shown in Scheme 1 by heat treatment at a predetermined temperature:

Scheme 1

In Scheme 1, R ₁ to R ₃ are the same as defined in Formula 1.

Since the carboxyl group has a property of dissolving at a constant rate in a developer such as an aqueous alkali solution, the carboxyl group may be developed at a desired rate during the process of forming a semiconductor capacitor. In addition, as described above, the silicone-based polymer has excellent storage stability, so that the development speed does not change significantly even after long-term storage, thereby increasing the reliability of the process.

The silicone-based polymer is not particularly limited as long as it includes a unit having silicon, and may be a siloxane-based polymer. The siloxane based polymer may be a polysilsesquioxane compound, for example.

One example of a polysilsesquioxane compound may be represented by Formula 2:

[Formula 2]

_{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m

In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer from 1 to 6, R ₁ R ₃ is as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000.

Another example of a polysilsesquioxane compound can be represented by Formula 3:

(3)

_{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m

In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 The alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m may be 12 to 2,000.

The silicone-based polymer may have a weight average molecular weight (Mw) of about 1,000 to 30,000, and in the case of having a weight average molecular weight (Mw) of about 1,000 to 10,000, it is advantageous in terms of filling.

The silicone-based polymer may be included in about 1 to 50% by weight relative to the total content of the filler. When included in the above range, the filler may be formed flat and evenly without a step between the part with and without the hole, regardless of the material and surface of the conductive layer, and may be smoothly filled without a void in the hole.

The filler may further include a thermal acid generator (TAG).

The thermal acid generator is an additive for improving the developability of the silicone-based polymer, and allows the silicone-based polymer to be developed at a relatively low temperature.

The thermal acid generator is not particularly limited as long as it is a compound capable of generating an acid (H ⁺ ) by heat. However, the thermal acid generator may be activated at about 90 ° C. or higher to generate sufficient acid, and may have low volatility. Such thermal acid generators can be selected, for example, from nitrobenzyl tosylate, nitrobenzyl benzenesulfonate, phenol sulfonate and combinations thereof.

The thermal acid generator may be included in an amount of about 0.01 to 25% by weight based on the total content of the filler, and when included in the above range, the silicone-based polymer may be developed at a relatively low temperature, and at the same time, the coating property may be improved.

The filler may further comprise a surfactant.

Surfactant is not specifically limited, For example, polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonyl phenol ether Polyoxyethylene alkyl allyl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, polyoxyethylene sorbita Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as tanmonostearate, polyoxyethylene sorbitan trioleate and polyoxyethylene sorbitan tristearate, F-top EF301, EF303, EF352 Products), Megapack F171, F173 (manufactured by Dainippon Ink Co., Ltd.), Prorad FC430, FC431 (Sumitomo ThreeM Co., Ltd.) Fluorine-based surfactants such as Asahi Guard AG710, Saffron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (Shin-Etsu Chemical Co., Ltd.) Note) manufactured) and other silicone surfactants.

The surfactant may be included in an amount of about 0.001 to 10% by weight based on the total content of the filler. When the surfactant is included in the above range, the dispersibility of the solution may be improved, and the uniformity and fillability of the film thickness may be increased during film formation.

The components may be in the form of a solution dissolved in a solvent.

The organic solvent is not particularly limited as long as it is a compound capable of dissolving the above-mentioned components, and examples thereof include alcohols such as methanol and ethanol; Ethers such as dichloroethyl ether, n-butyl ether, diisoamyl ether, methylphenyl ether and tetrahydrofuran; Glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; Cellosolve acetates such as methyl cellosolve acetate, ethyl cellosolve acetate and diethyl cellosolve acetate; Carbitols such as methyl ethyl carbitol, diethyl carbitol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol methylethyl ether and diethylene glycol diethyl ether; Propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate and propylene glycol propyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, methyl-n-propyl ketone, methyl-n-butylkenone, methyl-n-amyl ketone and 2-heptanone ; Saturated aliphatic monocarboxylic acid alkyl esters such as ethyl acetate, n-butyl acetate and isobutyl acetate; Lactic acid esters such as methyl lactate and ethyl lactate; Oxy acetic acid alkyl esters such as methyl oxy acetate, oxy ethyl acetate and oxy butyl acetate; Alkoxy acetate alkyl esters, such as methoxy methyl acetate, methoxy ethyl acetate, methoxy butyl acetate, ethoxy methyl acetate, and ethoxy ethyl acetate; 3-oxy propionic acid alkyl esters such as methyl 3-oxy propionate and ethyl 3-oxypropionate; 3-alkoxy propionic acid alkyl esters such as 3-methoxy methyl propionate, 3-methoxy ethyl propionate, 3-ethoxy ethyl propionate and 3-ethoxy methyl propionate; 2-oxy propionic acid alkyl esters such as 2-oxy methyl propionate, 2-oxy ethyl propionate and 2-oxy propionic acid propyl; 2-alkoxy propionic acid alkyl esters such as 2-methoxy methyl propionate, 2-methoxy ethyl propionate, 2-ethoxy ethyl propionate and 2-ethoxy methyl propionate; 2-oxy-2-methyl propionic acid esters, such as 2-oxy-2-methyl methyl propionate and 2-oxy-2-methyl ethyl propionate, 2-methoxy-2-methyl methyl propionate and 2-ethoxy-2- Monooxy monocarboxylic acid alkyl esters of 2-alkoxy-2-methyl propionic acid alkyls such as methyl methyl propionate; Esters such as 2-hydroxy ethyl propionate, 2-hydroxy-2-methyl ethyl propionate, hydroxy ethyl acetate, and 2-hydroxy-3-methyl butanoate; Compounds such as ketone acid esters, such as ethyl pyruvate, and N-methylformamide, N, N-dimethylformamide, N-methylformanilade, N-methylacetamide, and N, N-dimethylacetamide , N-methylpyrrolidone, dimethyl sulfoxide, benzyl ethyl ether, dihexyl ether, acetyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, High boiling point solvents, such as ethyl benzoate, diethyl oxalate, diethyl maleate, gamma -butyrolactone, ethylene carbonate, propylene carbonate, and phenyl cellosolve acetate, may be added. Among these, diethylene glycol monomethyl ether, diethylene glycol diethyl ether, ethyl-3-ethoxy propionate, methyl-3-methoxy propionate, cyclopentanone, cyclohexanone, and propylene glycol monomethyl ether acetate One or more selected from propylene glycol dimethyl ether acetate, 1-methoxy-2-propanol, ethyl lactate, cyclopentanone and ethyl hydroxy acetate can be selected.

In particular, at least one of the solvents may include a solvent having a high boiling point. In this case, voids can be prevented from occurring in the gap during gap filling, and the solvent is volatilized slowly to increase the flatness of the film.

  The solvent may be included in the balance except for the components described above with respect to the total filler content.

The above-mentioned fillers may be used in the electrode forming step in the manufacture of semiconductor capacitors, and specifically used to fill gaps in the mold for forming the electrodes in the manufacture of semiconductor capacitors.

As described above, the filler is excellent in developability and storage stability as well as excellent filling property for a gap having a high aspect ratio, and thus may be well filled in a fine gap. In addition, the fillers described above can be filled uniformly and densely without air voids or gaps, and the film surface has excellent flatness.

Hereinafter, a method of manufacturing a semiconductor capacitor according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. On the contrary, when a part is "just above" another part, there is no other part in the middle.

1 to 9 are cross-sectional views sequentially illustrating a method of manufacturing a semiconductor capacitor according to an embodiment of the present invention.

Referring to FIG. 1, a mold oxide film 3 is formed on a semiconductor substrate 1. In the semiconductor substrate 1, transistors (not shown), contact pads (not shown), contact plugs (not shown), and the like are formed. The mold oxide film 3 may be made of, for example, oxides such as silicon oxide (SiO ₂ ), tetraethylotho silicate (TEOS), boron phosphorus silicate glass (BPSG), and phosphor silicate glass (PSG), and chemical vapor deposition , CVD).

Next, referring to FIG. 2, the mold oxide film 3 is photo-etched to form a gap 2 exposing the contact plug of the semiconductor substrate 1. The gap 2 may be formed in a narrow and deep form having an aspect ratio of 1 or more, which is a ratio of height and width.

Next, referring to FIG. 3, a conductive layer 5 is stacked on the semiconductor substrate 1 and the mold oxide film 3. The conductive layer 5 may be a single layer or a plurality of layers, for example, made of a metal having low resistivity, such as aluminum (Al), copper (Cu), silver (Ag) and alloys thereof, or nickel (Ni) It may be made of a metal such as titanium (Ti), or made of polysilicon. The conductive layer 5 may be formed by a method such as sputtering or chemical vapor deposition.

Next, referring to FIG. 4, the filling layer 7 is formed on the conductive layer 5. The filling layer 7 may be formed by applying a filler including a silicone-based polymer, a thermal acid generator, a surfactant, and a solvent.

Here, the silicone polymer has a tertiary alkyloxycarbonyl group represented by the formula (1) at the terminal.

[Formula 1]

In Chemical Formula 1, R ₁ to R ₃ are the same as or different from each other, and are selected from a substituted or unsubstituted alkyl group of C1 to C3.

Here, the tertiary alkyloxycarbonyl group may be a t-butyloxycarbonyl group in which R ₁ to R ₃ are methyl groups.

The silicone-based polymer is not particularly limited as long as it includes a unit having silicon, and may be a siloxane-based polymer. The siloxane-based polymer may be, for example, a polysilsesquioxane compound, and may be a compound represented by Formula 2 or Formula 3:

[Formula 2]

_{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m

In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ CR ₁ R ₂ R ₃ , x is an integer from 1 to 6, R ₁ R ₃ is as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000.

(3)

_{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m

In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 The alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m may be 12 to 2,000.

The silicone-based polymer, the thermal acid generator and the surfactant may be included in an amount of 1 to 50% by weight, 0.01 to 25% by weight, and 0.001 to 10% by weight, respectively, based on the total content of the filler. May be included.

Next, the filling layer 7 is heat treated. By such heat treatment, the tertiary alkyloxycarbonyl group at the end of the silicone-based polymer of the packed layer 7 may be converted to a carboxyl group as in Scheme 1 below. Carboxyl groups can be readily developed in aqueous alkali solution in the subsequent development step:

Scheme 1

At this time, the heat treatment temperature may vary according to various conditions. When the packed layer 7 includes a thermal acid generator, it may be converted to a carboxyl group at a lower temperature by the acid (H ⁺ ) generated in the thermal acid generator as shown in Scheme 1, and thus may be performed at a relatively low temperature. Can be. However, the present invention is not limited thereto, and when the thermal acid generator is not included, the same result may be obtained by performing heat treatment at a relatively high temperature. The heat treatment can be carried out, for example, at about 160 to 250 ° C.

Next, referring to FIG. 5, the packed layer 7 is developed using a developer such as an aqueous alkali solution. At this time, the filling layer 7 may be developed at a constant speed by the carboxyl groups at the ends of the silicone-based polymer formed by the above-described heat treatment. Accordingly, the portion of the filling layer 7 formed on the lower conductive layer 5 is removed and only the portion filled in the gap 2 is left to leave the filling pattern 7a of a predetermined pattern.

Next, referring to FIG. 6, the portion of the conductive layer 5 positioned above the mold oxide layer 3 is removed, and only the portion of the conductive layer 5 located between the mold oxide layer 3 and the filling pattern 7a is left. ). In this case, the lower conductive layer 5 may be removed by chemical mechanical polishing (CMP) or etch back.

Next, referring to FIG. 7, the mold oxide film 3 and the charging pattern 7a are simultaneously removed to leave only the lower electrode 5a. The mold oxide film 3 and the filling pattern 7a may be removed by wet etching, and the wet etching is particularly limited as long as the material is capable of simultaneously etching the mold oxide film 3 and the filling pattern 7a. However, fluorine-containing etching solutions such as, for example, hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F) can be used.

Next, referring to FIG. 8, the dielectric layer 9 is formed on the entire surface of the substrate including the lower electrode 5a.

Next, referring to FIG. 9, the conductive layer is stacked on the dielectric layer 9 and then photo-etched to form the upper electrode 11.

The lower electrode 5a, the dielectric layer 9 and the upper electrode 11 form a capacitor.

Hereinafter, embodiments of the present invention described above will be described in more detail with reference to Examples. However, the following examples are merely for illustrative purposes and do not limit the scope of the present invention.

<Preparation of Filler and Film Coating>

Example  One

Approximately 25 poly-hydrogen silsesquioxanes (Dow Corning) having a weight average molecular weight (Mw) of 4,200 in a 3 L four-necked flask equipped with a mechanical stirrer, a cooling tube, a dropping funnel and a nitrogen gas introduction tube. g and about 75 g of t-butylo-3-butenoate (Sigma Aldrich) are mixed in a nitrogen atmosphere, followed by platinum catalyst (H ₂ PtCl ₆ , Sigma Aldrich) 2 g was added at 0 ° C. Thereafter, the mixture was left at room temperature for 6 hours and then filtered to obtain a silicone polymer having a dispersion degree (polydispersity, PD) of 2 and a weight average molecular weight (Mw) of 5,400.

10 g of the obtained silicone-based polymer was added to 100 g of propylene glycol monomethyl ether acetate, and the mixture was sufficiently stirred and diluted. Then, 1 g of IRGACURE # 121 (Shiba Corporation) with a thermal acid generator (TAG) and Zonyl as a surfactant. A solution was prepared by adding 0.1 g of FSO-100 (Dupont). A part of the prepared solution was applied to a silicon wafer by spin coating to heat-treat at various temperatures of about 100 to 240 ° C. for about 1 minute to form a film. The time taken for the coated film to fully develop when the coated wafer was immersed in a 2.38 wt% TMAH (trimethylammonium hydroxide) aqueous solution maintained at 23 ° C. using a DR measuring instrument (RDA-760, LTJ, Japan). That is, BTT (Break Through Time) was measured.

The remaining solution after application was put in a sealed bottle and stored at room temperature, and after three months spin coating on a silicon wafer under the same conditions and heat-treated at various temperatures of about 100 to 240 ℃ for 1 minute to form a film and measured the BTT.

Example  2

Except that 1 g of IRGACURE # 203 (Shiba Co., Ltd.) was used as a thermal acid generator (TAG), a solution was prepared in the same manner as in Example 1, and a BTT was measured after forming a film.

Example  3

Example 1 except that 25 g of hydrogen-methyl silsesquioxane copolymer (H / CH ₃ = 50/50, Dow Corning Co., Ltd.) having a weight average molecular weight (Mw) of 4,200 was used. In the same manner, a solution was prepared and a film was formed to measure BTT.

Example  4

Except that no thermal acid generator (TAG) and surfactant were used, the solution was prepared in the same manner as in Example 1, and the BTT was measured after the film was formed.

Comparative example  One

10 g of polyhydrogen silsesquioxane (Dow Corning Co., Ltd.) having a weight average molecular weight (Mw) of 4,200 was added to 100 g of propylene glycol monomethyl ether acetate, and the solution was sufficiently stirred to prepare a solution. The prepared solution was applied to a silicon wafer by spin coating to heat-treat at various temperatures of about 100 to 240 ° C. for about 1 minute to form a film. BTT was measured in the same manner as in Example 1, and the remaining solution after application was stored in a sealed bottle at room temperature in the same place as in Example 1.

Comparative example  2

A filler solution was prepared in the same manner as in Comparative Example 1 except that 10 g of a polyhydrogen silsesquioxane (Dow Corning Co., Ltd.) having a weight average molecular weight (Mw) of 5,400 was used to form a membrane, followed by BTT. Measured.

Comparative example  3

A filler solution was prepared in the same manner as in Comparative Example 1 except that 1 g of IRGACURE # 121 (Ciba) was used as a thermal acid generator (TAG) and 0.1 g of Zonyl FSO-100 (Dupont) was used as a surfactant. After formation, BTT was measured.

     <Evaluation 1>

Table 1 shows the results of measuring the BTT immediately after the preparation in the Examples 1 to 4 and Comparative Examples 1 to 3 and after 3 months storage at room temperature:

 TABLE 1

Heat treatment temperature (℃) BTT (seconds) Immediately after manufacture  3 months later Example 1 160 11.1 11.4 200 11.2 11.3 240 11.2 11.2 Example 2 160 N.D. N.D. 200 11.2 11.1 240 11.1 11.1 Example 3 160 27.6 27.9 200 27.7 27.8 240 27.6 27.8 Example 4 160 N.D. N.D. 200 N.D. N.D. 240 42.1 41.9 Comparative Example 1 160 N.D. N.D. 200 N.D. N.D. 240 N.D. N.D. Comparative Example 2 160 N.D. N.D. 200 N.D. N.D. 240 N.D. N.D. Comparative Example 3 160 N.D. N.D. 200 N.D. N.D. 240 N.D. N.D.

* N.D: Not developed.

As shown in Table 1, it can be seen that when the filler according to Examples 1 to 4 is used, the film is developed for a predetermined time at about 160 to 240 ° C. On the contrary, it can be seen that when the fillers according to Comparative Examples 1 to 3 are used, the development is not performed in the same temperature range. In Examples 1 to 4, unlike the comparative example, the silicon-based compound having a t-butyloxycarbonyl group at the terminal is converted into a carboxyl group by heat treatment, thereby improving developability. In addition, as can be seen in these examples, due to the inherent characteristics of the silicone-based compound having a t-butyloxycarbonyl group, it can be seen that the BTT does not change even when stored at room temperature for 3 months.

  <Evaluation 2>

Table 2 shows the results of measuring the molecular weight change of the solution immediately after preparation and after storage for 3 months at room temperature in Examples 1 to 4 and Comparative Examples 1 to 3.

TABLE 2

Weight average molecular weight (Mw) Immediately after manufacture 3 months later Example 1 5,400 5,500 Example 2 5,400 5,400 Example 3 5,400 5,500 Example 4 5,400 5,400 Comparative Example 1 4,200 6,300 Comparative Example 2 5,400 7,100 Comparative Example 3 4,200 8,700

As shown in Table 2, the fillers according to Examples 1 to 4 show little molecular weight change after 3 months at room temperature, whereas the fillers according to Comparative Examples 1 to 3 show a large change in molecular weight. This is because the fillers according to Examples 1 to 4 have excellent storage stability at room temperature by including a silicone-based compound having a t-butyloxycarbonyl group at the end, whereas the fillers according to Comparative Examples 1 to 3 have low reactivity due to their high reactivity. It can be seen.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

1 to 9 are cross-sectional views sequentially illustrating a method of manufacturing a semiconductor capacitor according to an embodiment of the present invention.

Claims (13)

Filler for semiconductor capacitor comprising a silicone-based polymer having a tertiary alkyloxycarbonyl group represented by the formula (1) at the terminal: [Formula 1]

In Chemical Formula 1, R ₁ to R ₃ are the same as or different from each other, and C1 to C3 are substituted or unsubstituted alkyl groups. In claim 1, The tertiary alkyloxycarbonyl group is a filler for a semiconductor capacitor comprising a t-butyloxycarbonyl group (t-butyloxycarbonyl). In claim 1, The silicone-based polymer is a filler for a semiconductor capacitor represented by Formula 2: [Formula 2] _{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ CR ₁ R ₂ R ₃ , x is an integer from 1 to 6, R ₁ R ₃ is as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000. In claim 1, The silicone-based polymer is a filler of a semiconductor capacitor represented by Formula 3: (3) _{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 Alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000. In claim 1, A filler of a semiconductor capacitor further comprising a thermal acid generator and a solvent. The method of claim 5, The silicon-based polymer, the thermal acid generator and the solvent are each 1 to 50% by weight, 0.01 to 25% by weight and the balance of the total amount of the filler, respectively, the filler of the semiconductor capacitor. Forming a mold having a gap on the semiconductor substrate, Forming a conductive layer on the semiconductor substrate and the mold; Applying a filler on the gap and the conductive layer to form a filling layer, Heat-treating the packed layer; Developing a portion of the filling layer to form a filling pattern filled in the gap, Removing a portion of the conductive layer to separate the plurality of first electrodes, Removing the mold and the filling pattern, Forming a dielectric layer over the first electrode, and Forming a second electrode on the dielectric layer Including, The filler comprises a silicone-based polymer having a tertiary alkyloxycarbonyl group represented by the formula (1) at the end  Method of manufacturing semiconductor capacitors: [Formula 1]

In Chemical Formula 1, R ₁ to R ₃ are the same as or different from each other, and are selected from a substituted or unsubstituted alkyl group of C1 to C3. 8. The method of claim 7, The tertiary alkyloxycarbonyl group is a manufacturing method of a semiconductor capacitor comprising a t-butyloxycarbonyl group (t-butyloxycarbonyl). 8. The method of claim 7, The silicon-based polymer is a method of manufacturing a semiconductor capacitor represented by Formula 2: [Formula 2] _{{(R 4 SiO 1 .5)} a (HSiO 1 .5) b (R 5 SiO 1 .5) c (Ar (CH 2) n SiO 1 .5) d} m In Formula 2, a + b + c + d = 1, 0.1 ≦ a ≦ 1.0, 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and R ₄ is — (CH ₂ ) _x (CO ₂ CR ₁ R ₂ R ₃ , x is an integer from 1 to 6, R ₁ R ₃ is as defined in Formula 1, R ₅ is a substituted or unsubstituted alkyl group of C1 to C12, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000. 8. The method of claim 7, The silicon-based polymer is a method of manufacturing a semiconductor capacitor represented by Formula 3: (3) _{{(R 6 SiO 1 .5)} e (HSiO 1 .5) f (R 7 SiO 1 .5) g (Ar (CH 2) n SiO 1 .5) h (SiO 1 .5 (CH 2) n SiO _{1 .5} ) _i } _m In Formula 3, e + f + g + h + i = 1, 0.1 ≦ e ≦ 1.0, 0 ≦ f ≦ 0.9, 0 ≦ g ≦ 0.9, 0 ≦ h ≦ 0.9, 0 ≦ i ≦ 0.9, R ₆ is -(CH ₂ ) _x (CO ₂ ) CR ₁ R ₂ R ₃ , x is an integer of 1 to 6, R ₁ to R ₃ are as defined in Formula 1, R ₇ is substituted or unsubstituted C1 to C12 Alkyl group, Ar is a substituted or unsubstituted aryl group of C6 to C20, n is an integer of 0 to 2, m is 12 to 2,000. 8. The method of claim 7, The filler further comprises a thermal acid generator and a solvent, The silicon-based polymer, the thermal acid generator and the solvent is 1 to 50% by weight, 0.01 to 25% by weight relative to the total content of the filler and the manufacturing method of the semiconductor capacitor. 8. The method of claim 7, Heat-treating the packed layer is a method of manufacturing a semiconductor capacitor carried out at 160 to 240 ℃. 8. The method of claim 7, Removing the mold and the filling pattern is a method of manufacturing a semiconductor capacitor using a fluorine-containing solution.

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