TWI910375B - Composition for forming silica layer, silica layer, and electronic device - Google Patents

Abstract

Provided are a composition for forming a silica layer, a silica layer manufactured therefrom, and an electronic device including the silica layer. The composition for forming the silica layer includes a silicon-containing polymer and a solvent, wherein a difference between a viscosity of 70% concentrated solid content and a viscosity of 50% concentrated solid content is 400 cps to 2,200 cps.

Description

Compositions for forming silicon dioxide layers, silicon dioxide layers, and electronic devices

This invention relates to an composition for forming a silicon dioxide layer, a silicon dioxide layer, and an electronic device manufactured from said silicon dioxide layer. Cross-reference to related applications.

This application claims priority and interest in Korean Patent Application No. 10-2021-0102652, filed on August 4, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

Flat panel displays use thin-film transistors (TFTs), which include gate electrodes, source electrodes, drain electrodes, and semiconductors, as switching devices. They are equipped with gate lines for transmitting scan signals used to control the TFTs and data lines for transmitting signals applied to pixel electrodes. Furthermore, an insulating layer is formed between the semiconductor and the electrodes to separate them. The insulating layer may be a silicon dioxide layer containing silicon components.

A silica layer with insulating properties can be formed using a coating solution containing inorganic polysilazane as a spin-on dielectric (SOD). In this case, the thickness (THK) of the silica layer varies depending on the location of the substrate, which may adversely affect subsequent processes and thus potentially have a negative impact on the insulation properties of the product.

Specifically, when a solution containing inorganic polysilazane is coated and cured onto a patterned wafer using a spin coating method, the thickness of the silicon dioxide layer varies depending on the location of the wafer, the position of the pattern blocks, etc. When the layer has an uneven thickness (THK), it can adversely affect processes such as chemical mechanical polishing (CMP).

Therefore, conventional techniques have attempted to address the problem by increasing the molecular weight of polysilazane synthesis, but this may lead to gelation issues due to contact with moisture when increasing the molecular weight of polysilazane.

One embodiment provides an composition for forming a silicon dioxide layer, which is capable of forming a film with a uniform thickness.

Another embodiment provides a silicon dioxide layer manufactured using a composition for forming a silicon dioxide layer.

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

According to an embodiment, the composition used to form the silica layer includes a silicone polymer and a solvent, wherein the difference between the viscosity of 70% concentrated solids content and the viscosity of 50% concentrated solids content is 400 centipoise to 2,200 centipoise.

The viscosity of a product with 70% concentrated solids content can range from 450 centipoise to 2,300 centipoise.

The viscosity of a product with 50% concentrated solids content can range from 20 centipoise to 100 centipoise.

Silicon-containing polymers may be polysilazane, polysiloxazane, or combinations thereof.

Polysilazane can be inorganic polysilazane.

The weight average molecular weight of silicone-containing polymers can range from 4,000 g/mol to 20,000 g/mol.

The amount of the silicon-containing polymer may be from 0.1% to 30% by weight, based on the total amount of the components used to form the silicon dioxide layer.

According to another embodiment, a silicon dioxide layer is provided, which is made from the aforementioned composition for forming a silicon dioxide layer.

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

By controlling the viscosity relative to the concentrated solids content of the components, the thickness distribution of the silica layer can be improved to achieve a silica layer with uniform thickness.

Examples and embodiments of this disclosure will be described in detail below and are readily applicable to persons with common knowledge in the relevant fields. However, this disclosure may be implemented in many different forms and should not be construed as limited to the examples and embodiments described herein.

In the diagrams, the thicknesses of layers, films, panels, zones, etc., are enlarged for clarity. Throughout the specification, the same reference numerals designate the same elements. It will be understood that when an element, such as a layer, film, zone, or substrate, is referred to as being "on" another element, it may be directly on the other element, or there may be intervening elements present. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements present.

In this specification, unless otherwise defined, 'substitution' means that at least one hydrogen atom of the compound is replaced by a substituent selected from: halogen atom (F, Br, Cl, or I), hydroxyl, alkoxy, nitro, cyano, amino, azido, amido, hydrazine, hydrazine, carbonyl, aminomethyl, thiol, ester, carboxyl or its salt, sulfonic acid or its salt, phosphate or its salt, C1 to C2. 20 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 this specification, unless otherwise defined, the term 'mixed' refers to a mixture containing one to three heteroatoms selected from N, O, S, and P.

Additionally, in the instruction manual, the symbol "*" indicates where something is connected to the same or different atoms or chemical formulas.

The following describes an embodiment of an composition for forming a silicon dioxide layer.

An embodiment of a composition for forming a silicon dioxide layer comprises a silicon-containing polymer and a solvent, wherein the difference between the viscosity at 70% concentrated solids content and the viscosity at 50% concentrated solids content can be from 400 centipoise to 2,200 centipoise, for example from 500 centipoise to 2,100 centipoise, for example from 800 centipoise to 2,000 centipoise.

When the difference between the viscosity of the composition used to form the silica layer at 70% concentrated solids content and the viscosity at 50% concentrated solids content is within the above range, the thickness distribution can be improved, and thus a silica layer with a uniform thickness can be implemented.

The difference between the viscosity of the composition used to form the silicon dioxide layer at 70% concentrated solids content and the viscosity at 50% concentrated solids content is within the above range, and the thickness standard deviation may be less than or equal to 10 nanometers, for example, from 1 nanometer to 10 nanometers, or from 3 nanometers to 8 nanometers.

In this invention, the viscosity of the composition used to form the silica layer is measured under the measurement conditions described below using an LVDV3 viscometer manufactured by Brookfield Engineering Laboratories, Inc.

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

Silicon-containing polymers may contain, for example, portions represented by chemical formula 1.

[Chemical Formula 1]

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

For example, a silicone-containing polymer can be a polysilazane produced by reacting a halogenated silane with ammonia.

For example, polysilazane can be inorganic polysilazane.

For example, the silicon-containing polymer contained in the composition used to form the silicon dioxide layer may include a portion represented by chemical formula 2.

[Chemical Formula 2]

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

For example, a silicone-containing polymer may contain a portion represented by chemical formula 1 and/or a portion represented by chemical formula 2, and may further contain a portion represented by chemical formula 3.

[Chemical Formula 3]

The portion represented by Formula 3 is a structure with hydrogen-capped ends, and may be contained in an amount of 15 to 35% by weight based on the total Si-H bonds of the polysilazane or polysiloxane structure. When the portion of Formula 3 is included in the above range of the polysilazane or polysiloxane structure, a sufficient oxidation reaction can occur during heat treatment, and during heat treatment, the _SiH3 portion is transformed into _SiH4 to prevent scattering, thereby preventing shrinkage and preventing cracking.

The weight-average molecular weight of the silicone-containing polymer can be from 4,000 g/mole to 20,000 g/mole, for example 5,000 g/mole to 20,000 g/mole, for example 6,000 g/mole to 20,000 g/mole, for example 7,000 g/mole to 15,000 g/mole, for example 7,000 g/mole to 10,000 g/mole, but is not limited thereto. When the weight-average molecular weight of the silicone-containing polymer is within the above range, the silicon dioxide layer made from the composition used to form the silicon dioxide layer can have improved film thickness uniformity characteristics.

For example, based on the composition used to form the silicon dioxide layer, the silicon-containing polymer may be included in an amount from 0.1% by weight to 30% by weight.

The solvent used to form the composition of the silicon dioxide layer may be, but is not limited to, any solvent in which the silicon-containing polymer can be dissolved, and specifically may include at least one selected from the following: benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, triethylbenzene, cyclohexane, cyclohexane Alkene, decalin, 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 components used to form the silica layer may further include a thermal acid generator (TAG).

The hot acid generator is an additive used to improve the development properties of the composition used to form the silica layer and to allow the development of the silicon-containing polymer contained in the composition at relatively low temperatures.

If a hot acid generator produces acid (H ⁺ ) due to heat, then it can contain any compound without specific limitations. More precisely, a hot acid generator can contain compounds that are activated at about 90°C or above, produce sufficient acid, and also have low volatility.

The hot acid generator may be selected, for example, from nitrobenzene toluenesulfonate, nitrobenzene benzenesulfonate, phenolsulfonate, and combinations thereof.

The hot acid generator may be included in an amount from about 0.01% by weight to about 25% by weight, based on the total amount of the components used to form the silica layer. Within this range, the condensed polymer can be developed at low temperatures while simultaneously exhibiting improved coating properties.

The components used to form the silica layer may further include surfactants.

Surfactants are not specifically limited and can be, for example, nonionic surfactants, such as polyoxyethylene alkyl ethers, such as polyoxyethylene dodecyl ether, polyoxyethylene octadecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene oleyl alcohol ether, 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.; fluorinated surfactants such as Ivto EF301 (EFTOP EF301), Ivto EF303, and Ivto EF352 (manufactured by Tochem Products Co., Ltd.), and MEGAFACE F171. F171), McGraw-Fis F173 (manufactured by Dainippon Ink & Chem., Inc.), Fluorad FC430, Fluorad FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), etc.; other silicone surfactants, such as organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

The surfactant may be included in an amount from 0.001% by weight to 10% by weight, based on the total amount of the components used to form the silica layer. Within this range, the dispersion of the solution can be improved, and at the same time, the uniformity of the layer thickness can be improved.

The composition used to form the silicon dioxide layer can be in the form of a solution in which the silicon-containing polymer and components are dissolved in a mixed solvent.

According to another embodiment, a method for manufacturing a silica layer includes: coating an ingredient for forming a silica layer, drying an ingredient for forming a substrate, and curing the ingredient for forming a silica layer.

The composition used to form the silicon dioxide layer can be coated by solution methods such as spin coating, slit coating, and inkjet printing.

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

Once the composition used to form the silica layer is fully coated, 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 in an atmosphere containing an inert gas by applying energy such as heat, ultraviolet radiation (UV), microwaves, sound waves, ultrasound, etc.

For example, drying can be performed at approximately 100°C to approximately 200°C, and solvent can be removed from the composition used to form the silica layer by drying. Additionally, curing can be performed at approximately 250°C to approximately 1,000°C, and the composition used to form the silica layer can be transformed into a thin oxide layer by curing.

According to another embodiment of the present invention, a silicon dioxide layer manufactured according to the aforementioned method is provided. The silicon dioxide layer may be, for example, an insulating layer, a separator, 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 manufactured according to the foregoing method is provided. The electronic device may be, for example, a display device, such as an LCD or 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

Synthetic Examples 1 Semi-finished products for the preparation of inorganic polysilazane ( A )

A 2-liter reactor equipped with a stirrer and temperature controller was purged with dry nitrogen. Then, 1,500 g of dried pyridine was added to the reactor and cooled to 5°C. Next, 100 g of dichlorosilane was slowly added over 1 hour. Then, 70 g of ammonia was slowly added to the reactor over 3 hours. After the ammonia was completely introduced, dry nitrogen was added for 30 minutes to remove any remaining ammonia from the reactor. 1,000 g of filtrate was obtained by filtering the resulting white slurry product through a 1-micron Teflon (tetrafluoroethylene) filter under a dry nitrogen atmosphere. After adding 1,000 g of dried xylene, the pyridine was repeatedly replaced with xylene three times using a rotary evaporator to adjust the solid content to 60%, and the product was filtered using a Teflon filter with a pore size of 0.1 micrometers. Using the above method, an inorganic polysilazane semi-finished product (A) with a solid content of 60% and a weight average molecular weight of 3,000 g/mole was obtained.

(Preparation of inorganic polysilazane)

Example 1

An assembly for forming a silica layer was prepared by placing 100 g of inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 350 g of dried pyridine, and 100 g of dried xylene into a 1-liter reactor equipped with a stirrer and a temperature controller, heating the mixture at 100°C, and repeatedly replacing its solvent with dibutyl ether four times at 70°C using a rotary evaporator to adjust the solid concentration to 50% and 70% respectively, and filtering each product with a 0.1-micron Teflon (tetrafluoroethylene) filter.

Example 2

An composition for forming a silica layer containing inorganic polysilazane with a weight average molecular weight of 10,000 g/mole was obtained in the same manner as in Example 1, except that 380 g of dried pyridine and 140 g of dried xylene were used.

Example 3

An composition for forming a silica layer containing inorganic polysilazane with a weight average molecular weight of 10,000 g/mole was obtained in the same manner as in Example 1, except that 410 g of dried pyridine and 180 g of dried xylene were used.

Example 4

An composition for forming a silica layer, comprising inorganic polysilazane with a weight average molecular weight of 8,000 g/mole, was obtained in the same manner as in Example 1. The difference was that 100 g of the inorganic polysilazane semi-finished product (A) of Example 1, 350 g of dried pyridine, and 100 g of dried xylene were placed in a 1-liter reactor equipped with a stirrer and a temperature controller and heated at 120°C while maintaining the reactor pressure at 1 bar.

Example 5

A composition for forming a silica layer, comprising inorganic polysilazane with a weight average molecular weight of 10,000 g/mole, was obtained in the same manner as in Example 1, except that 100 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 350 g of dried pyridine, 100 g of dried xylene, and 1000 cubic centimeters of _NH3 gas were placed in a 1-liter reactor equipped with a stirrer and a temperature controller.

Comparative example 1

A composition for forming a silica layer containing inorganic polysilazane with a weight average molecular weight of 5,500 g/mole was obtained in the same manner as in Example 1, except that 70 g of dried pyridine and 150 g of dried xylene were used.

Comparative example 2

An composition for forming a silicon dioxide layer containing inorganic polysilazane with a weight average molecular weight of 6,500 g/mole was obtained in the same manner as in Example 1, except that 80 g of dried pyridine and 140 g of dried xylene were used.

Comparative example 3

An composition for forming a silica layer containing inorganic polysilazane with a weight average molecular weight of 10,000 g/mole was obtained in the same manner as in Example 1, except that 140 g of dried pyridine and 80 g of dried xylene were used.

Comparative example 4

A composition for forming a silica layer, comprising inorganic polysilazane with a weight average molecular weight of 5,500 g/mole, was obtained in the same manner as in Example 1. The difference was that 100 g of the inorganic polysilazane semi-finished product (A) of Example 1, 70 g of dried pyridine, and 150 g of dried xylene were placed in a 1-liter reactor equipped with a stirrer and a temperature controller and then heated at 120°C while maintaining the reactor pressure at 1 bar.

Comparative example 5

A composition for forming a silica layer containing inorganic polysilazane with a weight average molecular weight of 5,500 g/mole was obtained in the same manner as in Example 1, except that 100 g of the inorganic polysilazane semi-finished product (A) according to Synthesis Example 1, 70 g of dried pyridine, 150 g of dried xylene, and 1000 cubic centimeters of _NH3 gas were placed in a 1-liter reactor equipped with a stirrer and a temperature controller.

evaluate 1 Viscosity measurement

In this invention, the viscosity of the composition used to form the silica layer is measured using a LVDV3 manufactured by Borelfeld Engineering Laboratories.

<Measurement Conditions>

(1) 50% concentrated solids content · Measurement temperature: 25℃±0.1℃ · Spindle: CPE-40 · Standard solution: 5.0 centipoise · Torque: 45% to 55% · RPM: 1 to 30

(2) 70% concentrated solids content · Measurement temperature: 25℃±0.1℃ · Spindle: CPE-52 · Standard solution: 990 centipoise · Torque: 45% to 55% · RPM: 1 to 30

After setting the above conditions, samples of the compositions according to Examples 1 to 5 and Comparative Examples 1 to 5, concentrated to 50% and 70% solid content, were placed in the viscometer container with a syringe at 0.5 ml. The viscosity was measured by inputting a torque range and RPM suitable for each sample after the measurement temperature was reached, and the results are shown in Table 1.

evaluate 2: Evaluate thickness uniformity

The compositions for forming silicon dioxide layers according to Examples 1 to 5 and Comparative Examples 1 to 5 were respectively coated onto wafers with a diameter of 8 inches using a spin coater (MS-A200, Mikasa Co., Ltd.). The patterns on the wafers had a linewidth of 0.2 to 10 micrometers and a space width of 0.2 micrometers.

Subsequently, the coated composition was pre-baked at 150°C for 3 minutes, heated to 1,000°C in an oxygen ( _O2 ) atmosphere, and cured at the corresponding temperature in an _H2 / _O2 atmosphere for 1 hour to form a silicon dioxide layer formed from the compositions according to Examples 1 to 5 and Comparative Examples 1 to 5.

Each patterned wafer coated with silicon dioxide is cut radially along its diameter, and the thickness at the thickness monitoring (TM, 90 μm × 90 μm) location is then measured using a SEM (SU-8230, Hitachi, Ltd.).

Figure 1 is a schematic diagram showing the thickness measurement locations of a patterned wafer used for thickness uniformity assessment.

As shown in Figure 1, the TM location contains 17 radial dies, and the thickness is measured at 5 points for each die, for a total of 85 points.

After the first coating, coatings were applied for 9 consecutive hours in 3-hour increments (0 hours, 3 hours, 6 hours, 9 hours), but changes over time were observed. In this paper, virtual assignments were performed at 5-minute intervals during the waiting time to prevent nozzle hardening, and the standard deviation of thickness was calculated for 3 sheets per coating (i.e., a total of 12 sheets), and the results are shown in Table 1.

(Table 1) Viscosity of concentrated solids content (unit: centipoise) Thickness standard deviation (nanometers) 50% 70% Viscosity difference (70% solids content - 50% solids content) Example 1 22.7 860 837.3 7.5 Example 2 24.5 1305 1280.5 6.1 Example 3 26.8 1974 1947.2 5.2 Example 4 22.3 832.3 810 7.8 Example 5 23.1 894.7 871.6 7.1 Comparative example 1 13.6 309.6 296 13.2 Comparative example 2 17.3 363.1 345.8 12.5 Comparative example 3 19.3 390.5 371.2 11.1 Comparative example 4 13.1 284.2 271.1 13.7 Comparative example 5 14.2 337.5 323.3 12.9

Referring to Table 1, the composition used to form the silicon dioxide layer according to Examples 1 to 5 showed a viscosity difference between 70% concentrated solids content and 50% concentrated solids content in the range of 400 centipoise to 2,200 centipoise, with a thickness standard deviation of less than 10 nanometers, thereby determining a uniform thickness.

Conversely, the compositions used to form the silica layer according to Comparative Examples 1 to 5 exhibited a difference between the viscosity at 70% concentrated solids content and the viscosity at 50% concentrated solids content that exceeded the scope of the present invention, wherein the thickness standard deviation was greater than 10 nanometers, thus confirming that the silica layer showed a relatively uneven thickness distribution.

Although the invention has been described in conjunction with what is now regarded as a practical example or embodiment, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended patent application.

without.

Figure 1 is a schematic diagram showing the thickness measurement locations of a patterned wafer used for thickness uniformity assessment.

Claims (8)

An assembly for forming a silica layer comprises a silica-containing polymer and a solvent, wherein the difference between the viscosity at 70% concentrated solids content and the viscosity at 50% concentrated solids content is 400 centipoise to 2,200 centipoise, wherein the silica-containing polymer is a polysilazane, a polysiloxane, or a combination thereof. The composition for forming a silicon dioxide layer as described in claim 1, wherein the viscosity of the 70% concentrated solids content is from 450 centipoise to 2,300 centipoise. The composition for forming a silicon dioxide layer as described in claim 1, wherein the viscosity of the 50% concentrated solids content is from 20 centipoise to 100 centipoise. The composition for forming a silicon dioxide layer as described in claim 1, wherein the polysilazane is an inorganic polysilazane. The composition for forming a silicon dioxide layer as described in claim 1, wherein the weight average molecular weight of the silicon-containing polymer is from about 4,000 g/mole to about 20,000 g/mole. The composition for forming a silicon dioxide layer as described in claim 1, wherein the silicon-containing polymer is contained in an amount from 0.1% to 30% by weight, based on the total amount of the composition for forming the silicon dioxide layer. A silicon dioxide layer, manufactured using the composition for forming a silicon dioxide layer as described in any one of claims 1 to 6. An electronic device comprising the silicon dioxide layer described in claim 7.