KR102619722B1 - Method of manufacturing transistor array panel and polishing slurry used the same - Google Patents

Abstract

The present disclosure relates to a method for manufacturing a transistor display panel and a polishing slurry used therefor. One embodiment includes forming a semiconductor layer on a substrate, patterning the semiconductor layer to form an active layer, the substrate and the active layer. forming a first insulating film covering the first insulating film, exposing the active layer by polishing the first insulating film, and forming a second insulating film covering the first insulating film and the active layer, The step of exposing the active layer by polishing the insulating film is performed using a polishing slurry containing abrasive particles, a dispersant, a dispersion stabilizer, a non-ionic polishing inhibitor, and a pH adjuster. Method for manufacturing a transistor display panel and a polishing slurry used therefor It's about.

Description

Method for manufacturing a transistor display panel and polishing slurry used therefor {METHOD OF MANUFACTURING TRANSISTOR ARRAY PANEL AND POLISHING SLURRY USED THE SAME}

The present disclosure relates to a method for manufacturing a transistor display panel and a polishing slurry used therefor.

A substrate containing a transistor is used as a means to implement a driving circuit for operating each pixel of a display device, such as a plasma display device, liquid crystal display device, or light emitting display device.

This transistor includes an active layer formed on a substrate and an insulating film covering the substrate and the active layer. In this insulating film deposition process, the upper surface of the insulating film covering the active layer and the upper surface of the insulating film covering the substrate have a thickness difference, that is, a step difference. If the insulating film has a step like this, the threshold voltage distribution of the gate electrode formed on the insulating film increases, thereby deteriorating the characteristics of the transistor display panel.

Embodiments are intended to provide a method for manufacturing a transistor display panel that can improve the display quality of the transistor display panel by removing steps in the insulating film covering the active layer, and a polishing slurry used therefor.

A method of manufacturing a transistor display panel according to an embodiment of the present disclosure includes forming a semiconductor layer on a substrate, patterning the semiconductor layer to form an active layer, and forming a first insulating film covering the substrate and the active layer. polishing the first insulating film to expose the active layer, forming a second insulating film covering the first insulating film and the active layer, and polishing the first insulating film to expose the active layer. The exposing step may be performed using an abrasive slurry containing abrasive particles, a dispersant, a dispersion stabilizer, a non-ionic abrasive inhibitor, and a pH adjuster.

Forming the first insulating film may be performed so that the first insulating film includes a first part covering the substrate and a second part covering the active layer.

The step of exposing the active layer by polishing the first insulating film may be performed so that the ratio of the polishing rate of the first portion and the polishing rate of the second portion is 1:5 or more.

The step of exposing the active layer by polishing the first insulating layer may be performed so that the first insulating layer and the active layer have the same thickness.

At this time, the active layer and the second insulating layer may be in direct contact.

The polishing slurry according to an embodiment of the present disclosure is used in the method of manufacturing the transistor display panel, and includes abrasive particles, an anionic polymer, a cationic polymer, a dispersant containing at least one of a hydroxyl acid and an amino acid, and an organic acid having a carboxyl group. It may include a dispersion stabilizer, a non-ionic polishing inhibitor, and a pH adjuster.

The abrasive particles may be one or more selected from the group consisting of wet ceria, dry ceria, silica, alumina, zirconia, and titania.

The abrasive particles may have a polyhedral structure or a structure with rounded edges.

The average particle diameter of the abrasive particles may be 40 nm to 150 nm.

The content of the abrasive particles may be 0.1% by weight to 10% by weight based on the total weight of the polishing slurry.

The anionic polymer may be one or more selected from the group consisting of oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, copolymers thereof, and salts thereof.

The content of the dispersant may be 0.003% by weight to 0.06% by weight based on the total weight of the polishing slurry.

The dispersion stabilizer is at least one selected from the group consisting of neutral amino acids, acidic amino acids, and basic amino acids, the neutral amino acids include at least one of alanine, glycine, tyrosine, and valine, and the acidic amino acids include aspartic acid and glutamic acid. It includes at least one, and the basic amino acid may include at least one of citric acid and lysine.

The content of the dispersion stabilizer may be 0.0004% by weight to 0.008% by weight based on the total weight of the polishing slurry.

The nonionic polishing inhibitors include polysorbate, octocynol, polyethylene glycol octadecyl ether, nonylphenol etoxylate, polyoxyl castor oil, ethylene oxide, glycerol ethoxylate, octylphenoxy polyethyleneoxy ethanol, and polyoxymethylene oxide. Containing ethylene nonylphenyl ether, polyoxyethylene dinonylphenyl ether, polyethylene glycol diglycidyl ether, hydroxycellulose, polyvinylpyrrolidone, polyacrylamide, and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer. There may be one or more types selected from the group.

The content of the nonionic polishing inhibitor may be 0.0002% by weight to 0.004% by weight based on the total weight of the polishing slurry.

The pH adjuster may be one or more selected from the group consisting of nitric acid, acetic acid, and phosphoric acid.

The pH of the polishing slurry may be 4 to 8.

The polishing slurry polishes the insulating film covering the active layer containing polycrystalline silicon.

According to embodiments, a method of manufacturing a transistor display panel with high resolution can be provided by forming a gate electrode on an insulating film with improved surface uniformity by removing steps in the insulating film covering the active layer.

Additionally, according to embodiments, it is possible to provide a polishing slurry that can easily remove steps in the insulating film covering the active layer.

1 to 6 sequentially show a method of manufacturing a transistor display panel according to an embodiment of the present disclosure.
Figures 7 and 8 each exemplarily show the crystal structure of abrasive particles included in a polishing slurry according to an embodiment of the present disclosure.
Figure 9 shows the results of measuring the polishing rate for a silicon oxide film and a polysilicon film using polishing slurries prepared according to Examples 1 to 4 and Comparative Examples 1 to 2.
Figure 10 shows the results of measuring the polishing rate for a silicon oxide film and a polysilicon film using the polishing slurry prepared according to Example 2, Examples 5 to 7, and Comparative Example 1.
Figure 11 shows the results of evaluation of polishing properties for the polishing slurry prepared according to Example 1.
Figure 12 shows the results of evaluating the polishing properties of the polishing slurry according to Example 8.
Figure 13 shows the results of evaluating the polishing properties of the polishing slurry according to Reference Example 1.
Figure 14 shows the results of evaluating the polishing properties of the polishing slurry according to Reference Example 2.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and identical or similar components are given the same reference numerals throughout the specification.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown. In the drawing, the thickness is enlarged to clearly express various layers and areas. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only cases where it is “directly above” another part, but also cases where there is another part in between. . Conversely, when a part is said to be “right on top” of another part, it means that there is no other part in between. In addition, being “on” or “on” a reference part means being located above or below the reference part, and does not necessarily mean being located “above” or “on” the direction opposite to gravity. .

In addition, throughout the specification, when a part is said to "include" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In addition, throughout the specification, when referring to “on a plane,” this means when the target portion is viewed from above, and when referring to “in cross section,” this means when a cross section of the target portion is cut vertically and viewed from the side.

Manufacturing method of transistor display board

An embodiment of a method for manufacturing a transistor display panel will be described in detail with reference to FIGS. 1 to 6.

1 to 6 sequentially show a method of manufacturing a transistor display panel according to an embodiment of the present disclosure.

As shown in FIG. 1, a buffer layer 120 and a semiconductor layer 130 are sequentially formed on the substrate 110. The semiconductor layer 130 may include polycrystalline silicon.

The semiconductor layer 130 is formed by forming an amorphous silicon layer and then crystallizing it using a laser crystallization process. The amorphous silicon layer can be formed by, for example, low-pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition, plasma enhanced chemical vapor deposition, sputtering, or vacuum evaporation.

Next, as shown in FIG. 2, the semiconductor layer 130 of FIG. 1 is patterned using a photo etching process or the like to form an active layer 131 having a first thickness h1, and the active layer 131 ) and a first insulating film 141 covering the buffer layer 120 is formed.

The active layer 131 includes a channel 131a formed through the above-described crystallization process, and a source region 131b and a drain region 131c located on both sides of the channel 131a, respectively.

The first insulating film 141 has a second thickness h2.

The first thickness h1 is defined as the shortest distance from the top surface 21 of the buffer layer 120 to the top surface 31 of the active layer 131. Additionally, the second thickness h2 is defined as the shortest distance from the top surface 21 of the buffer layer 120 to the top surface 41 of the first insulating film 141. In FIG. 2, the second thickness h2 may be formed to be greater than or equal to the first thickness h1.

The first insulating film 141 may include silicon oxide (SiOx) or silicon nitride (SiNx). At this time, the portion 141a of the first insulating film 141 that overlaps the active layer 131 forms a protrusion 141a, and the thickness of the first insulating film 141 in the protrusion 141a is the first thickness (h1). ) becomes as thick as the corresponding thickness. Accordingly, the upper surface of the first insulating film 141 has a step.

Specifically, the upper surface of the first insulating film 141 overlaps the first part 41, which is an area covering the buffer layer 120, and the second part 42, which is an area that overlaps the active layer 131 and covers the active layer 131. ) includes.

Next, a polishing process is performed as shown in FIG. 3.

The polishing process may be performed, for example, using a polishing device that performs a chemical mechanical polishing (CMP) process.

Referring to FIG. 3, the polishing device includes a polishing unit 50 that rotates and polishes an object, and a polishing control unit (not shown) that adjusts the rotation speed of the polishing unit 50. The polishing unit 50 includes a first surface plate 20 and a second surface plate 30 facing each other. The object to be polished is placed on the second surface plate 30, and the first surface plate 20 and the second surface plate 30 rotate with each other to polish the surface of the object sandwiched between them. At this time, the polishing slurry 51 is supplied to the surface of the object using a nozzle or the like. The specific composition of the polishing slurry will be described later.

In FIG. 3 , the object to be polished is the stepped upper surface of the first insulating film 141 laminated on the substrate 110. That is, the polishing slurry 51 according to the above-described embodiment is applied on the first insulating film 141, and the first insulating film 141 is planarized using a polishing device.

At this time, the ratio of the polishing rate of the first portion 41 and the polishing rate of the second portion 42 of the upper surface of the first insulating film 141 may be 1:5 or more. More specifically, the ratio of the polishing rate of the first portion 41 and the polishing rate of the second portion 42 may be 1:5 to 1:20 or 1:6 to 1:15.

When the polishing rate ratio of the first part 41 and the second part 42 satisfies the above range, the polishing time required to remove the step of the first insulating film 14 can be significantly shortened, and the polishing process is performed. The surface uniformity of the first insulating film 141 can be improved.

The polishing process is performed by flattening the first insulating film 141 until the top surface 31 of the active layer 131 is exposed, as shown in FIG. 4 .

Referring to FIG. 4, the first thickness (h1) of the active layer 131 is the same as the second thickness (h3) of the etched first insulating film 141, so the step on the upper surface of the first insulating film 141 is removed. You can see that

That is, in the polishing process of the present disclosure, since the polishing slurry 51 according to one embodiment is used, when the upper surface 31 of the active layer 131 is exposed by polishing the first insulating film 141, the upper surface 31 is exposed. This functions as a polishing stop film to stop the polishing process of the first insulating film 141. Accordingly, the step of the first insulating film 141 can be easily removed, and thus the surface uniformity of the first insulating film 141 can be improved.

If the upper surface 31 of the active layer 131 has hydrophilic properties, abrasive particles remaining after the polishing process may be easily absorbed. However, as described above, when a polishing process is performed using the polishing slurry 51 according to an embodiment, a hydrophobic protective film is formed on the active layer 131, thereby preventing contamination due to adsorption of residual abrasive particles, etc. You can.

Next, as shown in FIG. 5, a second insulating film 142 is formed covering the first insulating film 141 and the active layer 131, and a gate electrode 155 is formed on the second insulating film 142. .

The gate electrode 155 may be positioned to overlap the channel 131a of the active layer 131. In addition, the gate electrode 155 is a stack of a metal film containing any one of copper (Cu), copper alloy, aluminum (Al), and aluminum alloy, and a metal film containing any one of molybdenum (Mo) and molybdenum alloy. It may be multi-act.

In the present disclosure, by flattening the first insulating film 141 to remove the step, the threshold voltage distribution of the gate electrode 155 can be reduced, and thus a high-resolution transistor display panel can be easily implemented.

FIG. 6 is a cross-sectional view of a transistor display panel according to an embodiment manufactured according to FIGS. 1 to 5.

As shown in FIG. 6, an interlayer insulating film 160 is formed on the gate electrode 155 and the second insulating film 142. Then, a source electrode 176 and a drain electrode 177 connected to the source region 131b and the drain region 131c of the active layer 131, respectively, are formed on the interlayer insulating film 160 to form the gate electrode 155 and the active The transistor TR including the layer 131, the source electrode 176, and the drain electrode 177 is completed. Then, a protective film 180 is formed covering the interlayer insulating film 160, the source electrode 176, and the drain electrode 177. A pixel electrode 710 connected to the drain electrode 177 is formed on the protective film 180, thereby completing the transistor display panel.

Next, a polishing slurry according to an embodiment used in the method of manufacturing the transistor display panel will be described.

polishing slurry

The polishing slurry according to one embodiment may include abrasive particles, a dispersant, a dispersion stabilizer, a non-ionic polishing inhibitor, and a pH adjuster.

The polishing slurry of the present disclosure is used in the method of manufacturing a transistor display panel according to the above-described embodiment. In particular, it can be used in the planarization process of an insulating film covering an active layer containing polycrystalline silicon.

(1) Abrasive particles

In the present disclosure, the abrasive particles include, for example, metal oxides such as wet ceria, dry ceria, silica, alumina, zirconia, titania, etc. It can be included. These may be used individually or in combination of two or more types.

In the present disclosure, the abrasive particles may be wet ceria.

7 and 8 show exemplary TEM images of the crystal structure of wet ceria particles. The crystal structure of the wet ceria particles may be, for example, a polyhedral structure as shown in FIG. 7 or a round cubic structure as shown in FIG. 8. Specifically, a polyhedral crystal structure has a relatively sharp shape, and a round cubic structure may have a shape close to a circle with curved edges. The crystal structure of these ceria particles can be analyzed through X-ray diffraction (XRD) measurement.

The average particle diameter of the abrasive particles may be, for example, about 40 nm to about 150 nm. More specifically, the average particle diameter of the abrasive particles may be about 50 nm to about 90 nm or about 60 nm to about 80 nm. If the average particle diameter of the abrasive particles is about 40 nm or more, it is easy to polish the object to be polished, so the surface uniformity of the object to be polished can be easily secured. In addition, if the average particle diameter of the polishing particles is about 150 nm or less, it is possible to prevent the polishing object from being overpolished or scratches occurring on the surface of the polishing object. Therefore, when the average particle diameter of the abrasive particles satisfies the above range, it is possible to easily remove the steps of the polishing object and at the same time prevent scratches from occurring.

For example, the content of the abrasive particles may be about 0.1% by weight to about 10% by weight based on the total weight of the polishing slurry. More specifically, the content of abrasive particles may be about 0.1% by weight to about 2% by weight or about 0.5% by weight to about 1.5% by weight. When the content of the abrasive particles is 0.1% by weight or more, an appropriate polishing speed for the polishing object can be secured, and when the content of the abrasive particles is 10% by weight or less, it is possible to prevent the polishing object from being overpolished or surface scratches occurring. You can.

(2) Dispersant

In the present disclosure, the dispersant serves to prevent agglomeration between abrasive particles and uniformly disperse them within the polishing slurry. The dispersant is selected from the group consisting of materials capable of converting the surface potential of the abrasive particles to negative, for example, anionic polymers, cationic polymers, hydroxyl acids, and amino acids. It may include one or more types.

The anionic polymers include, for example, oxalic acid, citric acid, polysulphonic acid, polyacrylic acid, polymethacrylic acid, and their copolymers. It may be one or more types selected from the group consisting of polymers and salts thereof.

The cationic polymers include, for example, polylysine, polyethyleneimine, benzethonium chloride, Bronidox, Cetrimonium bromide, and Cetrimonium chloride. (CetrimoniumChloride), Dimethyldioctadecylammonium chloride, Tetramethylammonium hydroxide, Distearyl dimethyl ammonium chloride, polymer of dimethylamine and epichlorohydrin (Polydimethylamine-co) -epichlorohydrin), 1,2-dioleoyl-3-trimethylammonium propane, and poly allyl amine.

The hydroxyl acid may be, for example, one or more selected from the group consisting of hydroxybenzoic acid, ascorbic acid, and salts thereof.

The amino acid may be, for example, one or more selected from the group including picolinic acid, glutamic acid, tryptophane, aminobutyric acid, and salts thereof.

The above dispersants may be used individually or in combination.

In this embodiment, an anionic polymer may be used as the dispersant. Since the anionic polymer has a high zeta potential, it can effectively disperse abrasive particles even at a low concentration. Among the anionic polymers, for example, polyacrylic acid or polymethacrylic acid may be used, and their weight average molecular weight may be 5,000 to 20,000.

For example, the content of the dispersant may be about 0.003% by weight to about 0.06% by weight based on the total weight of the polishing slurry. More specifically, the content of the dispersant may be 0.015% by weight to 0.045% by weight. If the dispersant content is 0.003% by weight or more, the dispersion stability of the polishing slurry can be sufficiently secured and precipitation can be prevented. In addition, if the content of the dispersant is 0.06% by weight or less, it is possible to prevent agglomeration of the polymer dispersant or an increase in ionization concentration, thereby preventing a decrease in dispersion stability.

(3) Dispersion stabilizer

In the present disclosure, the dispersion stabilizer serves to improve dispersibility by adsorbing to the abrasive particles and increasing the absolute value of zeta potential. The dispersion stabilizer may include an organic acid having a negative charge due to a carboxyl group. In addition, the dispersion stabilizer suppresses chemical changes in the polishing slurry by acting as a pH buffer, preventing agglomeration between polishing particles and dispersing them uniformly.

As a dispersion stabilizer, for example, an amino acid, more specifically, an α-amino acid in which a carboxyl group and an amine group are bonded to the same carbon atom can be used. The α-amino acids include neutral amino acids with the same number of carboxyl groups (-COOH) and amine groups (-NH ₂ ), acidic amino acids with more carboxyl groups (-COOH) than amine groups (-NH ₂ ), and amine groups ( A basic amino acid in which the number of -NH ₂ ) is greater than the number of carboxyl groups (-COOH) can be used.

For example, the neutral amino acid may be Alanine, Glycine, Tyrosine, Valine, etc., and the acidic amino acid may be Aspartic acid, Glutamic acid, etc. , the basic amino acid may be citric acid, lysine, etc.

The content of the dispersion stabilizer may be about 0.0004% by weight to about 0.008% by weight based on the total weight of the polishing slurry. More specifically, the content of the dispersion stabilizer may be 0.002% by weight to 0.006% by weight. When the content of the dispersion stabilizer is 0.0004% by weight or more, the pH buffer capacity is excellent, and when the content of the dispersion stabilizer is 0.008% by weight or less, the dispersion stability of the polishing slurry can be easily secured.

(4) Polishing inhibitor

In the present disclosure, the polishing inhibitor may be a nonionic polymer material containing both hydrophobic and hydrophilic groups. The hydrophobic group included in the polishing inhibitor can be easily combined with the active layer exposed by polishing the first insulating layer in the process of polishing the first insulating layer covering the active layer using the polishing slurry of the present disclosure. Accordingly, the hydrophilic group contained in the polishing inhibitor is located on the surface of the active layer, and a thin hydrophobic protective film is formed on the surface of the active layer. Since this protective film reduces the polishing rate of the active layer, the polishing process of the first insulating film also stops when the thickness of the active layer and the thickness of the first insulating film are the same. That is, the active layer exposed by polishing the first insulating film functions as a polishing stop film for the first insulating film. Therefore, when using a polishing slurry containing the polishing inhibitor, steps in the first insulating film can be easily removed.

The nonionic polishing inhibitor is, for example, polysorbate , octoxynol, polyethylene glycol octadecyl ether, nonylphenol ethoxylate, polyoxyl Polyoxyl castor oil, Eethylene oxide, Glycerol ethoxylate, Octylphenoxy poly ethyleneoxy ethanol, Polyoxyethylene nonylphenyl ether, Polyoxyethylene dinonylphenyl ether, Polyethylene glycol diglycidyl ether, Hydroxyethyl cellulose, Polyvinylpyrrolidone, Polyethylene glycol ), including polyacrylamide and polypropylene glycol-polyethylene glycol-polypropylene glycol block copolymer (Poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol, PEP block copolymer) It may be one or more types selected from the group.

The content of the nonionic polishing inhibitor may be, for example, about 0.0002% by weight to about 0.004% by weight based on the total weight of the polishing slurry. More specifically, the content of the nonionic polishing inhibitor may be about 0.001% by weight to about 0.003% by weight. When the content of the polishing inhibitor satisfies the above range, when the active layer containing polycrystalline silicon is exposed during the polishing process of the first insulating film, the exposed surface can function as a polishing stop film that stops the polishing process of the first insulating film. , Accordingly, the surface uniformity of the first insulating film on which the polishing process has been performed can be improved.

(5) Others

The polishing slurry may have an appropriate pH depending on the polishing target. For example, in this example, the pH of the polishing slurry may be about 4 to 8, and more specifically, about 6 to 7. When the pH of the polishing slurry satisfies the above range, the dispersion stability of the polishing slurry according to the present disclosure can be secured, and the first insulating film to be polished, which will be described later, can be polished uniformly and quickly.

The polishing slurry may further include a pH adjuster to have an appropriate pH. The pH adjusting agent may be, for example, one or more selected from the group consisting of nitric acid, acetic acid, and phosphoric acid.

The polishing slurry of the present disclosure may include the remainder of the solvent in addition to the abrasive particles, dispersant, dispersion stabilizer, and nonionic polishing inhibitor.

The content of the solvent may be the remainder excluding the content of the abrasive particles, the dispersant, the stabilizer, and the hydrophilic treatment agent.

Additionally, as the solvent, for example, deionized water may be used.

The polishing slurry according to one embodiment may be used in a planarization process of the first insulating film that covers the active layer containing polycrystalline silicon and has a step. Accordingly, since the surface uniformity of the first insulating film can be easily improved, the threshold voltage distribution of the gate electrode formed on the first insulating film can be reduced, and as a result, the characteristics of the transistor display panel can be improved.

Additionally, since the polishing slurry according to one embodiment includes a polishing inhibitor having both hydrophobic and hydrophilic groups, when the active layer is exposed during the planarization process of the insulating film, a hydrophobic protective film is formed on the surface of the active layer. As a result, the polishing rate for the active layer can be reduced, and as a result, the polishing process for the insulating film covering the active layer can be automatically stopped without separate manipulation.

The present disclosure will be examined in detail through examples below.

Example One

1% by weight of wet ceria powder with an average particle diameter of 70 nm, 0.03% by weight of Darvan C-N (Vanderbilt Minerals), polymethacrylic acid as a dispersant, 0.004% by weight of citric acid as a dispersion stabilizer, and polypropylene glycol-polyethylene glycol-poly as a nonionic polishing inhibitor. Mix 0.001% by weight of propylene glycol block copolymer (Poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol), PEP block copolymer) and extra deionized water, and add nitric acid to adjust pH. A polishing slurry of 6.5 was prepared.

Example 2

A polishing slurry was prepared in the same manner as in Example 1, except that 0.002% by weight of polypropylene glycol-polyethylene glycol-polypropylene glycol block copolymer was used as a nonionic polishing inhibitor.

Example 3

A polishing slurry was prepared in the same manner as in Example 1, except that 0.004% by weight of polypropylene glycol-polyethylene glycol-polypropylene glycol block copolymer was used as a nonionic polishing inhibitor.

Example 4

A polishing slurry was prepared in the same manner as Example 1, except that 0.002% by weight of polyvinylpyrrolidone (PVP) was used as a nonionic polishing inhibitor.

Example 5

A polishing slurry was prepared in the same manner as in Example 1, except that 0.002% by weight of hydroxyethyl cellulose (HEC) was used as a nonionic polishing inhibitor.

Example 6

A polishing slurry was prepared in the same manner as in Example 1, except that 0.002% by weight of polyethylene glycol (PEO) was used as a nonionic polishing inhibitor.

Example 7

A polishing slurry was prepared in the same manner as in Example 1, except that 1% by weight of wet ceria powder with an average particle diameter of 80 nm and 0.002% by weight of a nonionic polishing inhibitor were used.

Comparative example One

A polishing slurry was prepared in the same manner as Example 1, except that it did not contain a nonionic polishing inhibitor.

Comparative example 2

A polishing slurry was prepared in the same manner as in Example 1, except that 0.0001% by weight of polypropylene glycol-polyethylene glycol-polypropylene glycol block copolymer was used as a nonionic polishing inhibitor.

Comparative example 3

A polishing slurry was prepared in the same manner as in Example 1, except that 0.006% by weight of polypropylene glycol-polyethylene glycol-polypropylene glycol block copolymer was used as a nonionic polishing inhibitor.

Reference example One

The same polishing slurry as Example 1 was prepared except that 1% by weight of wet ceria powder with an average particle diameter of 20 nm was used.

Reference example 2

The same polishing slurry as Example 1 was prepared except that 1% by weight of wet ceria powder with an average particle diameter of 30 nm was used.

Experiment example 1 - Measurement of removal rate

The polishing rates for silicon oxide films and polysilicon films were measured using the polishing slurries prepared according to Examples 1 to 6 and Comparative Examples 1 to 3. The results are shown in Table 1 below. In addition, Figure 9 shows the polishing rate measurement results according to the content of the polishing inhibitor, and Figure 10 shows the polishing rate measurement results according to the type of polishing inhibitor.

division Polishing inhibitor types Polishing inhibitor content (wt%) SiO ₂ film polishing rate
[Å/min] Poly-Si film polishing rate
[Å/min] Example 1 PEP 0.001 1078 74 Example 2 PEP 0.002 1081 10 Example 3 PEP 0.004 948 11 Example 4 PVP
0.002 1021 163 Example 5 H.E.C.
0.002 1067 55 Example 6 PEO 0.002 1033 25 Comparative Example 1 - 0 1084 251 Comparative Example 2 PEP 0.0001 1073 209 Comparative Example 3 PEP 0.006 826 9

Referring to Table 1 and FIGS. 9 and 10, the polishing slurries according to Examples 1 to 6 containing a polishing inhibitor are either Comparative Example 1, which does not contain a polishing inhibitor, or Comparative Example 2, which contains a very low content of the polishing inhibitor. Compared to the polishing slurry according to , the polishing rate for the silicon oxide film is similar, but the polishing rate for the polysilicon film is very low. In addition, it was confirmed that the polishing slurry according to Comparative Example 3 containing an excessive amount of a polishing inhibitor had a low polishing rate for a polysilicon film, but also a low polishing rate for a silicon oxide film.

Therefore, when the polishing slurry according to Comparative Examples 1 and 2 is used in the process of polishing a silicon oxide film, the polishing process may not be stopped even if the active layer containing polycrystalline silicon is exposed. In addition, when using the polishing slurry according to Comparative Example 3, the polishing process time becomes longer and productivity decreases, making it unsuitable for the transistor display panel manufacturing process.

On the other hand, in the case of the polishing slurry according to Examples 1 to 6 containing an appropriate amount of a polishing inhibitor, when the active layer containing polycrystalline silicon is exposed, the polishing rate for the active layer is significantly reduced, so that the insulating film containing silicon oxide It can be confirmed that the polishing process can be stopped. In addition, since the polishing rate for the silicon oxide film is excellent, it can be seen that the productivity of the transistor display panel is also excellent.

Experimental Example 2 - Evaluation of polishing characteristics

An amorphous silicon film with a thickness of 47.5 nm was formed on a glass substrate (size: 730 × 920), and a polycrystalline silicon film was formed through excimer laser annealing. Next, a silicon oxide film with a thickness of 50 nm was formed on the glass substrate and the polycrystalline silicon film.

Using the polishing slurry prepared according to Examples 2 and 7 and Reference Examples 1 and 2 and a polishing machine (POLI-300, G&P), the surface of the silicon oxide film was polished at a rotation speed of 80/80 RPM (head/pad). did. The polishing amount, polishing rate, and step removal time were measured and shown in Table 2 below, and the polishing amount according to polishing time is shown in Figures 11 to 14. In Table 2 and Figures 11 to 14, the surface of the silicon oxide film formed on the glass substrate is referred to as the first part, and the surface of the silicon oxide film positioned overlapping the polycrystalline silicon film is referred to as the second part. Additionally, the step removal time refers to the time taken for the silicon oxide film to be polished so that the polycrystalline silicon film and the silicon oxide film have the same thickness.

division Example 2 Example 7 Reference example 1 Reference example 2 Polishing amount
[nm] part 1 5.87 5.19 15.43 14.25 second part 60.40 59.72 69.96 68.78 Step removal time [s] 34.s 25.2 98.8 61.5 Polishing rate
[nm/min] part 1 10.1 12.4 9.5 13.1 second part 103.8 142.2 42.5 67.1 Ratio of the polishing rate of the first portion and the polishing rate of the second portion 1:11.5 1:8.7 1:4.5 1:4.8 polishing efficiency 0.88 0.91 0.78 0.79

Referring to Table 2 and FIGS. 11 to 14, the polishing slurries prepared according to Examples 2 and 7 are compared to the polishing slurries prepared according to Reference Examples 1 and 2, for the polishing rate of the first portion. It can be seen that the ratio of the polishing rate of the second part is significantly high.

In this way, since the ratio of the polishing rate of the second surface to the polishing rate of the first portion is high at 1:5 or more, the time required to remove the step can be significantly shortened. In addition, it can be seen that the polishing slurry according to the example has excellent polishing efficiency and the polishing process is performed to have a uniform surface. Therefore, when the polishing slurry according to the present disclosure is applied to the manufacturing process of a transistor display panel, the uniformity of the surface removed can be improved and the polishing time can be shortened, thereby significantly improving productivity.

As described above, the present invention has been described through limited examples and drawings, but the present invention is not limited thereto, and the technical idea of the present invention and the description below will be understood by those skilled in the art to which the present invention pertains. Various modifications and variations are possible within the scope of equivalence of the patent claims.

110: substrate
120: buffer layer
130: semiconductor layer
131: active layer
141: first insulating film
142: second insulating film
51: Polishing slurry

Claims (19)

forming a semiconductor layer on a substrate;
patterning the semiconductor layer to form an active layer;
forming a first insulating film covering the substrate and the active layer;
exposing the active layer by polishing the first insulating layer;
forming a second insulating film covering the first insulating film and the active layer;
Including,
The step of exposing the active layer by polishing the first insulating film is performed using a polishing slurry containing abrasive particles, a dispersant, a dispersion stabilizer, a non-ionic polishing inhibitor, and a pH adjuster,
The method of manufacturing a transistor display panel wherein the content of the nonionic polishing inhibitor is 0.0002% by weight to 0.004% by weight based on the total weight of the polishing slurry. According to paragraph 1,
The step of forming the first insulating film is,
A method of manufacturing a transistor display panel, wherein the first insulating film includes a first portion covering the substrate and a second portion covering the active layer. According to paragraph 2,
The step of exposing the active layer by polishing the first insulating film includes:
A method of manufacturing a transistor display panel, wherein the ratio of the polishing rate of the first portion to the polishing rate of the second portion is 1:5 or more. According to paragraph 1,
The step of exposing the active layer by polishing the first insulating film includes:
A method of manufacturing a transistor display panel, wherein the first insulating layer and the active layer are performed to have the same thickness. According to paragraph 1,
A method of manufacturing a transistor display panel in which the active layer and the second insulating layer are in direct contact. A polishing slurry used in the method of manufacturing a transistor display panel according to claim 1,
Abrasive particles;
A dispersing agent containing at least one of anionic polymer, cationic polymer, hydroxyl acid, and amino acid;
A dispersion stabilizer containing an organic acid having a carboxyl group;
Nonionic polishing inhibitors; and
pH regulator
Including,
The content of the nonionic polishing inhibitor is 0.0002% by weight to 0.004% by weight based on the total weight of the polishing slurry. According to clause 6,
The abrasive particles are,
An abrasive slurry that is at least one selected from the group consisting of wet ceria, dry ceria, silica, alumina, zirconia, and titania. According to clause 6,
The crystal structure of the abrasive particles is
Abrasive slurry with polyhedral or round cubic structure. According to clause 6,
A polishing slurry wherein the average particle diameter of the abrasive particles is 40 nm to 150 nm. According to clause 6,
A polishing slurry in which the content of the abrasive particles is 0.1% by weight to 10% by weight based on the total weight of the polishing slurry. According to clause 6,
The anionic polymer is a polishing slurry that is at least one selected from the group consisting of oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, copolymers thereof, and salts thereof. According to clause 6,
The content of the dispersant is 0.003% by weight to 0.06% by weight based on the total weight of the polishing slurry. According to clause 6,
The dispersion stabilizer is at least one selected from the group consisting of neutral amino acids, acidic amino acids, and basic amino acids,
The neutral amino acid includes at least one of alanine, glycine, tyrosine, and valine,
The acidic amino acid includes at least one of aspartic acid and glutamic acid,
A polishing slurry wherein the basic amino acid includes at least one of citric acid and lysine. According to clause 6,
The content of the dispersion stabilizer is 0.0004% by weight to 0.008% by weight based on the total weight of the polishing slurry. According to clause 6,
The nonionic polishing inhibitors include polysorbate, octocynol, polyethylene glycol octadecyl ether, nonylphenol etoxylate, polyoxyl castor oil, ethylene oxide, glycerol ethoxylate, octylphenoxy polyethyleneoxy ethanol, and polyoxymethylene oxide. Containing ethylene nonylphenyl ether, polyoxyethylene dinonylphenyl ether, polyethylene glycol diglycidyl ether, hydroxycellulose, polyvinylpyrrolidone, polyacrylamide, and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer. One or more polishing slurries selected from the group. delete According to clause 6,
A polishing slurry wherein the pH adjuster is at least one selected from the group consisting of nitric acid, acetic acid, and phosphoric acid. According to clause 6,
A polishing slurry wherein the pH of the polishing slurry is 4 to 8. According to clause 6,
The polishing slurry is
Polishing slurry for polishing the insulating film covering the active layer containing polycrystalline silicon.

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