TWI874780B - Composition for forming silica layer, silica layer, and electronic device - Google Patents

Abstract

Provided are a composition for forming a silica layer including a silicon-containing polymer and a solvent, wherein a RI (Refractive Index) reduction rate calculated by Relation 1 is less than or equal to 3%, a silica layer manufactured therefrom, and an electronic device including the silica layer. RI (Refractive Index) reduction rate (%) = {(RI ₁₀₀- RI ₂₅₀) / RI ₁₀₀} * 100 In Relation 1, RI ₁₀₀: the refractive index measured at a wavelength of 633 nm by coating the composition for forming the silica layer on an 8-inch bare wafer to a thickness of 7200 Å, and baking at a temperature of 100 °C for 3 minutes, and RI ₂₅₀: a refractive index measured at a wavelength of 633 nm by coating the composition for forming the silica layer on an 8-inch bare wafer to a thickness of 7200 Å, and baking at a temperature of 250 °C for 3 minutes.

Description

Composition for forming silicon dioxide layer, silicon dioxide layer and electronic device

The present disclosure relates to a composition for forming a silicon dioxide layer, a silicon dioxide layer, and an electronic device made from the silicon dioxide layer.

Cross-references to related applications

This application claims priority to and the benefits of Korean Patent Application No. 10-2021-0080288 filed on June 21, 2021, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

In a flat panel display device, a thin film transistor (TFT) including a gate electrode, a source electrode, a drain electrode, and a semiconductor is used as a switching element. The flat panel display device includes a gate line for transmitting a scanning signal for controlling the thin film transistor and a data line for transmitting a signal applied to a pixel electrode. In addition, an insulating layer for separating them is formed between the semiconductor and various electrodes. The insulating layer may be a silicon dioxide layer including a silicon component.

In order to provide a silicon dioxide layer with insulating properties, a coating liquid containing inorganic polysilazane is used as a spin-on dielectric (SOD). In this case, the thickness (THK) of the silicon dioxide layer varies depending on the position of the substrate, which may have an adverse effect on the following process, thereby having an adverse effect on the insulating properties of the product.

Specifically, when an inorganic polysilazane solution is applied and cured on a patterned wafer by a spin coating method, a phenomenon occurs in which the thickness of the silicon dioxide layer varies depending on the location of the wafer, the location of the patterned block, etc. When the layer has a non-uniform thickness (THK), it may have an adverse effect on the following processes such as chemical mechanical polishing (CMP).

Therefore, conventional techniques have attempted to solve the problem by increasing the molecular weight of the synthesized polysilazane, but this may cause a problem of gelation due to contact with moisture when the molecular weight of the polysilazane is increased.

One embodiment provides a composition for forming a silicon dioxide layer that can form a film having a uniform thickness and with less occurrence of void defects.

Another embodiment provides a silicon dioxide layer made from a composition for forming a silicon dioxide layer.

Another embodiment of the present invention provides an electronic device including a silicon dioxide layer.

According to an embodiment, a composition for forming a silicon dioxide layer comprises a silicon-containing polymer and a solvent, wherein a refractive index (RI) reduction rate calculated by Relation 1 is less than or equal to 3%. [Relationship 1] Refractive index (RI) reduction rate (%) = {(RI ₁₀₀ - RI ₂₅₀ ) / RI ₁₀₀ } * 100 In Relationship 1, RI ₁₀₀ : a refractive index measured at a wavelength of 633 nanometers by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 100°C for 3 minutes, and RI ₂₅₀ : a refractive index measured at a wavelength of 633 nanometers by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 250°C for 3 minutes.

The refractive index (RI) reduction can be less than 3%.

The silicon-containing polymer may be polysilazane, polysiloxazane or a combination thereof.

The polysilazane may be an inorganic polysilazane.

The weight average molecular weight of the silicon-containing polymer may be from 4,000 g/mol to 20,000 g/mol.

The silicon-containing polymer may be included in an amount of 0.1 wt % to 30 wt % based on the total amount of the composition for forming the silicon dioxide layer.

According to another embodiment, a silicon dioxide layer manufactured from the above-mentioned composition for forming a silicon dioxide layer is provided.

According to another embodiment, an electronic device including the aforementioned silicon dioxide layer is provided.

By controlling the reactivity with water, a silicon dioxide layer with fewer void defects and uniform thickness can be achieved.

The embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention relates can easily practice the embodiments of the present invention. However, the present disclosure can be implemented in many different forms and should not be construed as being limited to the exemplary embodiments described herein.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. The same reference numerals designate the same elements throughout the specification. It will be understood that when an element, such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element, or intervening elements may also be present. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

In the present specification, when no additional definition is provided, "substituted" means that the hydrogen of the compound is replaced by a substituent selected from the following: 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 amidino group, a hydrazine group, a hydrazone group, a carbonyl group, a carbamoyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphate group or a salt thereof, a C1 to C20 The invention also includes but is not limited to the following: alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C30 aryl, C7 to C30 aralkyl, C1 to C30 alkoxy, C1 to C20 heteroalkyl, C2 to C20 heteroaryl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, C2 to C30 heterocycloalkyl and combinations thereof.

In addition, in the present specification, when no definition is provided otherwise, "impurity" means containing one of 1 to 3 impurity atoms selected from N, O, S and P.

In addition, in this specification, "*" means a part that is bonded to the same or different atoms or chemical formulas.

Hereinafter, a composition for forming a silicon dioxide layer according to an embodiment of the present invention is described.

According to an embodiment of the present invention, the composition for forming a silicon dioxide layer includes a silicon-containing polymer and a solvent, and a refractive index (RI) reduction rate calculated by Relational Formula 1 is less than or equal to 3%. [Relationship 1] Refractive index (RI) reduction rate (%) = {(RI ₁₀₀ - RI ₂₅₀ ) / RI ₁₀₀ } * 100 In Relationship 1, RI ₁₀₀ : a refractive index measured at a wavelength of 633 nanometers by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 100°C for 3 minutes, and RI ₂₅₀ : a refractive index measured at a wavelength of 633 nanometers by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 250°C for 3 minutes.

The RI reduction indicates the extent to which the silicon-containing polymer reacts with moisture in the air.

In other words, the silicon-containing polymer reacts with moisture and thus forms Si-O bonds, and the composition for forming the silicon dioxide layer is cured after coating, wherein the more Si-O bonds there are, the lower the RI reduction rate is. Therefore, since the RI reduction rate calculated according to Relational Formula 1 is smaller, the degree of Si-O bond formation (i.e., reactivity with moisture) can be lower.

The silica layer formed from the composition for the silica layer having a small RI reduction rate can suppress reactivity with moisture and volume expansion with moisture and thus be uniformly formed.

In addition, since the formation of Si-O bonds is suppressed, since the gas generated when the silicon-containing polymer is formed into the silicon dioxide layer during curing can be easily removed, the void defects caused by the gas on the surface of the silicon dioxide layer can be greatly improved.

In other words, when Relationship 1 is greater than or equal to about 3, for example, less than about 3, the composition for forming a silicon dioxide layer according to an embodiment can form a uniform film having smaller voids and exhibiting satisfactory gap filling.

In the present invention, M-2000 manufactured by J.A. WOOLLAM Co. is used to measure the refractive index at a wavelength of about 633 nanometers, and the refractive index reduction rate according to the baking temperature is calculated therefrom and used as an indicator of reactivity with moisture.

The silicon-containing polymer in the composition for forming the silicon dioxide layer may be, for example, an organic-inorganic polysilazane, an organic-inorganic polysiloxazane, or a combination thereof.

The silicon-containing polymer may include, for example, a moiety represented by Chemical Formula 1. [Chemical Formula 1]

In Formula 1, _R1 to _R3 are each independently hydrogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C3 to C30 cycloalkyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C7 to C30 aralkyl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C2 to C30 heterocycloalkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkoxy, carboxyl, aldehyde, hydroxyl, or a combination thereof, and "*" indicates a bond point.

For example, the silicon-containing polymer may be a polysilazane produced by the reaction of a halogenated silane with ammonia.

For example, the polysilazane may be an inorganic polysilazane.

For example, the silicon-containing polymer included in the composition for forming the silicon dioxide layer may include a moiety represented by Chemical Formula 2. [Chemical Formula 2]

_R4 to _R7 of Chemical Formula 2 are each independently hydrogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C3 to C30 cycloalkyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C7 to C30 aralkyl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C2 to C30 heterocycloalkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkoxy, carboxyl, aldehyde, hydroxyl, or a combination thereof, and "*" indicates a bond point.

For example, the silicon-containing polymer may include a moiety represented by Chemical Formula 1 and/or a moiety represented by Chemical Formula 2, and may further include a moiety represented by Chemical Formula 3. [Chemical Formula 3]

The moiety represented by Chemical Formula 3 is a structure terminated with hydrogen at the end, and may be contained in an amount of 15 to 35 wt % based on the total amount of Si-H bonds of the polysilazane or polysiloxazane structure. When the moiety of Chemical Formula 3 is contained in the polysilazane or polysiloxazane structure within the range, SiH ₃ is prevented from being partially dispersed into SiH ₄ , while an oxidation reaction is sufficiently performed during heat treatment, and cracks in the filler pattern can be prevented.

The weight average molecular weight of the silicon-containing polymer may be 4,000 g/mol to 20,000 g/mol, such as 5,000 g/mol to 20,000 g/mol, such as 6,000 g/mol to 20,000 g/mol, such as 7,000 g/mol to 15,000 g/mol, such as 7,000 g/mol to 10,000 g/mol, but is not limited thereto. When the weight average molecular weight of the silicon-containing polymer satisfies the above range, the silicon dioxide layer manufactured by the composition for forming the silicon dioxide layer may have excellent film thickness uniformity characteristics.

For example, the silicon-containing polymer may be included in an amount of 0.1 wt % to 30 wt % based on the composition for forming the silicon dioxide layer.

The solvent included in the composition for forming the silicon dioxide layer is not particularly limited as long as it is a solvent capable of dissolving the silicon-containing polymer, and specifically, may include at least one selected from the group consisting of benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, triethylbenzene, cyclohexane, cyclohexene, decahydronaphthalene, dipentene, pentane, hexane, heptane, octane, nonane, decane, ethylcyclohexane, methylcyclohexane, cyclohexane, cyclohexene, p-menthane, dipropyl ether, dibutyl ether, anisole, butyl acetate, amyl acetate, methyl isobutyl ketone, and combinations thereof.

The composition for forming the silicon dioxide layer may further include a thermal acid generator (TAG).

The thermal acid generator may be an additive for improving the developability of the composition for forming the silicon dioxide layer and thereby developing the organic silane-based condensation polymer of the composition at a relatively low temperature.

If the thermal acid generator generates acid (H ⁺ ) due to heat, it may include any compound without particular limitation. Specifically, the thermal acid generator may include a compound that is activated at 90° C. or higher and generates sufficient acid and also has low volatility.

The thermal acid generator can be, for example, selected from nitrobenzyl toluenesulfonate, nitrobenzyl benzenesulfonate, phenolsulfonate, and combinations thereof.

The thermal acid generator may be included in an amount of 0.01 wt % to 25 wt % based on the total amount of the composition for forming the silica layer, and within the range, the condensation polymer can be developed at a low temperature and at the same time have improved coating properties.

The composition for forming the silicon dioxide layer may further include a surfactant.

The surfactant is not particularly limited and may be a nonionic surfactant such as the following: polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene octadecyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl alcohol, etc.; polyoxyethylene alkyl allyl ethers, such as polyoxyethylene nonylphenol ether, etc.; polyoxyethylene·polyoxypropylene block copolymers; polyoxyethylene sorbitan fatty acid esters, such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, etc.; fluorine-based surfactants such as EFTOP EF301, EF303, and EF352 (Tochem Products Co., Ltd.), MEGAFACE F171 (MEGAFACE F171), Magfish F173 (Dainippon Ink & Chem., Inc.), FLUORAD FC430, FLUORAD FC431 (Sumitomo 3M), Asahi guardAG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.), etc.; other silicone surfactants, such as organosiloxane polymer KP341 (Shin-Etsu Chemical Co., Ltd.), etc.

The surfactant may be included in an amount of 0.001 wt % to 10 wt % based on the total amount of the composition for forming the silica layer, and within the range, the dispersion of the solution may be improved and at the same time, the uniform thickness of the layer may be improved.

The composition for forming the silicon dioxide layer may be in the form of a solution in which the silicon-containing polymer and the components are dissolved in a mixed solvent.

According to another embodiment, a method for preparing a silicon dioxide layer may include: applying the aforementioned composition for forming a silicon dioxide layer, drying the substrate on which the aforementioned composition for forming a silicon dioxide layer is applied, and curing the composition for forming a silicon dioxide layer.

For example, the composition for forming the silicon dioxide layer can be applied using a solution method such as spin coating, slit coating, or inkjet printing.

The substrate may be, for example, a device substrate such as a semiconductor, a liquid crystal, etc., but is not limited thereto.

When the coating of the composition for forming the silicon dioxide layer is completed, the substrate is then dried and cured. Drying and curing can be performed, for example, at a temperature greater than or equal to about 100° C., and can be performed by applying energy such as heat, ultraviolet light, microwaves, sound waves, or ultrasound waves.

For example, drying may be performed at about 100° C. to about 200° C., and the solvent in the composition for forming the silicon dioxide layer may be removed by drying. In addition, curing may be performed at about 250° C. to 1,000° C., and the composition for forming the silicon dioxide layer may be converted into a thin oxide film by curing.

According to another embodiment of the present invention, a silicon dioxide layer manufactured according to the above method is provided. The silicon dioxide layer can be, for example, an insulating layer, a separation layer, a hard coating layer, etc., but is not limited thereto.

According to another embodiment of the present invention, an electronic device comprising a silicon dioxide layer is provided. The electronic device may be, for example, a display device, such as an LCD or an LED; or a semiconductor device.

The following examples illustrate embodiments of the present invention in more detail. However, these examples are exemplary and the present disclosure is not limited thereto. Preparation of a composition for forming a silicon dioxide layer Synthesis Example 1 : Preparation of a semi-finished product of an inorganic polysilazane ( A )

The interior of a 2-liter reactor equipped with a stirrer and a temperature controller was replaced with dry nitrogen. Subsequently, 1,500 grams of dry pyridine was placed therein, and then cooled to 5°C. Then, 100 grams of dichlorosilane was slowly added thereto over 1 hour. Subsequently, 70 grams of ammonia was slowly added thereto over 3 hours. When the ammonia was completely added thereto, dry nitrogen was added thereto for 30 minutes, and the remaining ammonia in the reactor was removed therefrom. The obtained white slurry product was filtered with a 1 micron TEFLON (tetrafluoroethylene) filter under a dry nitrogen atmosphere to obtain 1,000 grams of filtrate. After adding 1,000 g of dry xylene, the solid content was adjusted to 60% by repeatedly replacing the solvent from pyridine to xylene using a rotary evaporator three times, and then filtered using a Teflon (tetrafluoroethylene) filter with a pore size of 0.1 μm. By this method, an inorganic polysilazane semi-finished product (A) having a solid content of 60% and a weight average molecular weight of 3,000 g/mol was obtained. ( Preparation of Inorganic Polysilazane ) Example 1

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 400 g of dry pyridine, 80 g of dry xylene, and 6500 cm3 of _NH3 gas in a 1-liter reactor equipped with a stirrer and a temperature controller, heating it to 100°C, and repeatedly replacing the solvent with dibutyl ether 4 times at 70°C with a rotary evaporator to adjust the solid concentration to 20%, and then filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter to obtain an inorganic polysilazane having a weight average molecular weight of 9,200 g/mol. Example 2

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 350 g of dry pyridine, 70 g of dry xylene, and 3250 cm3 of _NH3 gas in a 1-liter reactor equipped with a stirrer and a temperature controller, heating it to 100°C, and repeatedly replacing the solvent with dibutyl ether 4 times at 70°C using a rotary evaporator to adjust the solid concentration to 20%, and then filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter to obtain an inorganic polysilazane having a weight average molecular weight of 9,400 g/mol. Example 3

50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 513 g of dry pyridine and 50 g of dry xylene were placed in a 1-liter reactor equipped with a stirrer and a temperature controller and heated to 100° C. During the reaction, the reactor pressure was maintained at 3 bar. When the reaction was completed, a composition for forming a silicon dioxide layer was obtained by repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. to adjust the solid concentration to 20% and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter, the composition having a weight average molecular weight of 7,100 g/mol and containing an inorganic polysilazane. Comparative Example 1

50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 200 g of dry pyridine and 80 g of dry xylene were placed in a 1-liter reactor equipped with a stirrer and a temperature controller and heated to 100° C. During the reaction, the reactor pressure was maintained at 3 bar. When the reaction was completed, a composition for forming a silicon dioxide layer was obtained by repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. to adjust the solid concentration to 20% and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter, the composition having a weight average molecular weight of 10,500 g/mol and containing an inorganic polysilazane. Comparative Example 2

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 150 g of dry pyridine, and 70 g of dry xylene in a 1-liter reactor equipped with a stirrer and a temperature controller, heating it to 100° C., repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. using a rotary evaporator to adjust the solid concentration to 20%, and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter. The composition contains an inorganic polysilazane having a weight average molecular weight of 9,400 g/mol. Comparative Example 3

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 120 g of dry pyridine, and 60 g of dry xylene in a 1-liter reactor equipped with a stirrer and a temperature controller, heating it to 100° C., repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. using a rotary evaporator to adjust the solid concentration to 20%, and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter. The composition contains an inorganic polysilazane having a weight average molecular weight of 8,500 g/mol. Comparative Example 4

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 513 g of dry pyridine and 50 g of dry xylene in a 1-liter reactor equipped with a stirrer and a temperature controller, adding 1.5 mol% N,N,N',N'-tetramethyl-1,6-hexanediamine thereto based on the weight of the inorganic polysilazane semi-finished product (A), heating the mixture to 100° C., repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. with a rotary evaporator to adjust the solid concentration to 20%, and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter. The composition contained an inorganic polysilazane having a weight average molecular weight of 5,500 g/mol. Comparison Example 5

A composition for forming a silicon dioxide layer was obtained by placing 50 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 513 g of dry pyridine and 50 g of dry xylene in a 1-liter reactor equipped with a stirrer and a temperature controller, adding 3.0 mol% of N,N,N',N'-tetramethyl-1,6-hexanediamine based on the weight of the inorganic polysilazane semi-finished product (A), heating the mixture to 100° C., repeatedly replacing the solvent with dibutyl ether 4 times at 70° C. with a rotary evaporator to adjust the solid concentration to 20%, and filtering the solid with a 0.1 μm Teflon (tetrafluoroethylene) filter. The composition contains an inorganic polysilazane having a weight average molecular weight of 9,500 g/mol. Evaluation 1 : Measuring RI reduction

3 cm3 of the composition for forming a silicon dioxide layer according to Examples 1 to 3 and Comparative Examples 1 to 5 were respectively extracted, and then coated on the center of a bare wafer having a diameter of 8 inches, and spun at 1500 rpm for 20 seconds using a spin coater (MS-A200, MIKASA Co., Ltd.), baked at 100°C for 3 minutes, and the refractive index ( _RI100 ) at a wavelength of 633 nm was measured by using M-2000 (JA Woollam).

In addition, after baking at 250°C for 3 minutes, another refractive index (RI ₂₅₀ ) at a wavelength of 633 nm was measured by using M-2000 (JA Woollam).

The refractive index at 100°C and 250°C is used to calculate the RI reduction rate according to the following Relationship 1. [Relationship 1] Refractive index (RI) reduction rate (%) = {(RI ₁₀₀ - RI ₂₅₀ ) / RI ₁₀₀ } * 100 In Relationship 1, RI ₁₀₀ : a refractive index measured at a wavelength of 633 nm by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 100°C for 3 minutes, and RI ₂₅₀ : a refractive index measured at a wavelength of 633 nm by coating a composition for forming a silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 250°C for 3 minutes.

The RI reduction calculated from equation 1 is shown in Table 1. Evaluation 2: Evaluation of thickness uniformity

The compositions for forming a silicon dioxide layer according to Examples 1 to 3 and Comparative Examples 1 to 5 were respectively coated on an 8-inch diameter wafer patterned to have a line width of 0.2 to 10 μm and a space width of 0.2 μm by using a spin coater (MS-A200, Mikasa Co., Ltd.).

Subsequently, the coated wafer was baked at 150°C for 3 minutes, heated to 1,000°C in an oxygen (O ₂ ) atmosphere, and cured at the corresponding temperature for 1 hour in an H ₂ /O ₂ atmosphere to obtain a silicon dioxide layer formed of each composition according to Examples 1 to 5 and Comparative Examples 1 to 5.

The patterned wafer coated with the silicon dioxide layer was cut into radial forms along the diameter, and then the thickness at the Thickness Monitoring (TM, 90 μm × 90 μm) position was measured by using SEM (SU-8230, Hitachi, Ltd.).

FIG. 5 is a schematic diagram showing thickness measurement locations of a patterned wafer for thickness uniformity evaluation.

As shown in Figure 5, the TM site includes 17 radial dies, and the thickness of each die is measured at 5 points per die, for a total of 85 points.

After the initial coating, although more coatings were performed for 9 hours in units of 3 hours (0 hours, 3 hours, 6 hours, 9 hours), changes over time were observed. During the waiting time, virtual dispensing was performed at 5-minute intervals to prevent nozzle hardening, and the standard deviation of thickness was calculated for 3 pieces per coating, a total of 12 pieces, and the results are plotted in Table 1. Evaluation 3 : Evaluation of void defects

3 cubic centimeters of each composition for forming a silicon dioxide layer according to Examples 1 to 3 and Comparative Examples 1 to 5 was extracted and coated on an 8-inch wafer patterned to have a line width of 0.2 to 10 μm and a space width of 0.2 μm by using a spin coater (MS-A200, Mikasa Co., Ltd.).

Subsequently, the coated wafer was heated and dried on a heating plate at 150° C. for 3 minutes, and wet-cured at 1,000° C. for 60 minutes, to obtain a silicon dioxide layer formed of each composition according to Examples 1 to 3 and Comparative Examples 1 to 5.

Cross sections of the samples were cut to expose fine patterns, immersed in 1 wt % dilute hydrofluoric acid (DHF) for 120 s, washed with DI water, dried with N ₂ gas, and subsequently examined by FE-SEM micrographs.

Based on the degree of void defects confirmed by FE-SEM images, the standards are given in the order of good/bad/poor, and are then shown in Table 1. (Good: no voids in the gap, voids less than 1.0 micron in size account for less than or equal to 10% of the area; Poor: voids greater than or equal to 1.0 micron in size account for less than 30% of the area; Bad: voids greater than 1.0 micron in size account for greater than or equal to 90% of the area) [Table 1] RI ₁₀₀ RI ₂₅₀ RI reduction rate (%) Thickness deviation (micrometer) Void Defect Example 1 1.57707 1.53563 2.63 5.4 good Example 2 1.57841 1.53602 2.69 5.6 good Example 3 1.57601 1.53344 2.70 5.1 good Comparison Example 1 1.5786 1.530001 3.08 13.4 Difference Comparison Example 2 1.57917 1.52417 3.48 30.2 Difference Comparison Example 3 1.57889 1.53099 3.03 14.2 Difference Comparison Example 4 1.57860 1.50424 4.71 25.5 bad Comparison Example 5 1.57872 1.49854 5.08 48.4 bad

Referring to Table 1 and FIGS. 1 to 4 , the compositions for the silicon dioxide layer according to Examples 1 to 3 exhibited an RI reduction of less than or equal to 3%, and specifically, less than 3%, and a thickness deviation of 10 μm or less, and improved void defects.

In contrast, the compositions for the silicon dioxide layer according to Comparative Examples 1 to 5 exhibited an RI reduction rate of greater than 3% and a thickness deviation of greater than 10 μm.

2 to 4 , the silicon dioxide layer formed from the composition for a silicon dioxide layer according to the comparative example exhibits a relatively small number of voids in a cross-section of each silicon dioxide layer after wet etching, compared to the silicon dioxide layer formed from the composition for a silicon dioxide layer according to the comparative example.

Although the present invention has been described in conjunction with what are currently considered to be practical example embodiments, it should be understood that the present invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims.

without

FIG. 1 is a graph showing the correlation between the RI reduction rate of the composition for forming a silicon dioxide layer according to Examples 1 to 3 and Comparative Examples 1 to 4 and the standard deviation of the thickness of the silicon dioxide layer. FIG. 2 shows a FE-SEM image of the inside of the gap of the patterned wafer after wet etching of the silicon dioxide layer manufactured by the composition for forming a silicon dioxide layer according to Examples 1 to 3. FIG. 3 shows a FE-SEM image of the inside of the gap of the patterned wafer after wet etching of the silicon dioxide layer manufactured by the composition for forming a silicon dioxide layer according to Comparative Examples 1 to 3. FIG. 4 shows a FE-SEM image of the inside of the gap of the patterned wafer after wet etching of the silicon dioxide layer made of the composition for forming the silicon dioxide layer according to Comparative Example 4 and Comparative Example 5. FIG. 5 is a schematic diagram showing the thickness measurement position of the patterned wafer for thickness uniformity evaluation.

Claims (6)

A composition for forming a silicon dioxide layer, comprising: a silicon-containing polymer, wherein the silicon-containing polymer is polysilazane, polysiloxazane or a combination thereof; and a solvent, wherein a refractive index RI reduction rate calculated by relational formula 1 is less than or equal to 3%: [Relational formula 1] Refractive index RI reduction rate (%) = {(RI ₁₀₀ -RI ₂₅₀ )/RI ₁₀₀ }*100 Wherein, in relational formula 1, RI ₁₀₀ : the refractive index measured at a wavelength of 633 nanometers by coating the composition for forming the silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 100° C. for 3 minutes, and RI ₂₅₀ : A refractive index measured at a wavelength of 633 nanometers by coating the composition for forming the silicon dioxide layer on an 8-inch bare wafer to a thickness of 7200 angstroms and baking at a temperature of 250° C. for 3 minutes, wherein the silicon-containing polymer is contained in an amount of 0.1 wt % to 30 wt % based on the total amount of the composition for forming the silicon dioxide layer, and wherein the silicon-containing polymer includes a portion represented by Chemical Formula 1 and a portion represented by Chemical Formula 3: [Chemical Formula 1]

[Chemical Formula 3] * -SiH ₃ In Chemical Formula 1, R ₁ to R ₃ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 aralkyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocycloalkyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a carboxyl group, an aldehyde group, a hydroxyl group, or a combination thereof, and “*” indicates a bonding point, and the moiety represented by Chemical Formula 3 is included in an amount of 15 wt % to 35 wt % based on the total amount of Si—H bonds of the polysilazane or the polysiloxazane. A composition for forming a silicon dioxide layer as described in claim 1, wherein the refractive index RI reduction rate is less than 3%. A composition for forming a silicon dioxide layer as described in claim 1, wherein the polysilazane is an inorganic polysilazane. A composition for forming a silicon dioxide layer as described in claim 1, wherein the weight average molecular weight of the silicon-containing polymer is 4,000 g/mol to 20,000 g/mol. A silicon dioxide layer made from a composition for forming a silicon dioxide layer as described in any one of claims 1 to 4. An electronic device comprising a silicon dioxide layer as described in claim 5.