KR102013397B1 - Etching composition, method of forming a metal pattern and method of manufacturing a display substrate - Google Patents

Abstract

In the etching solution composition, the method of forming the metal pattern and the manufacturing method of the display substrate, the etching solution composition of the copper-based metal film is 0.1% to 30% by weight of ammonium persulfate, 0.1% to 10% by weight of sulfate, 0.01% to 5% of acetate Weight percent and 55 weight percent to 99.79 weight percent water. Accordingly, the storage stability of the etchant composition and the processing ability of the substrate can be improved.

Description

Etching liquid composition, method of forming a metal pattern, and method of manufacturing a display substrate {ETCHING COMPOSITION, METHOD OF FORMING A METAL PATTERN AND METHOD OF MANUFACTURING A DISPLAY SUBSTRATE}

The present invention relates to an etching solution composition, a method of forming a metal pattern and a method of manufacturing a display substrate, and more particularly, to an etching solution composition of etching a metal film containing copper, a method of forming a metal pattern and a method of manufacturing a display substrate. .

As display devices become larger and consumers demand higher resolutions, the gate wiring or data wiring becomes longer and thinner, and the resistance gradually increases. Accordingly, a problem of RC delay occurs. To solve this problem, the gate line and the data line are mainly formed of a low resistance metal.

As a low resistance metal for forming the gate wiring and the data wiring, copper has advantages of excellent electrical conductivity, rich amount of residual material, and very low resistance compared to aluminum or chromium. On the other hand, since the resistance to oxidant is larger than that of aluminum or chromium, a strong oxidant is required for etching the copper film.

Korean Patent Laid-Open Publication No. 2000-79355 discloses a mixture of hydrogen peroxide (H ₂ O ₂ ) and an inorganic acid or a neutral salt as an etchant for a copper film, and Korean Patent Laid-Open Publication No. 2005-00682 discloses hydrogen peroxide, a copper reaction inhibitor, and a stable fruit water. An etchant comprising an agent and a fluoride ion is disclosed. In addition, Korean Patent Laid-Open Publication No. 2006-64881 discloses an etching solution in which five additives including fluorine compounds, organic molecules, and the like are added to hydrogen peroxide, and Korean Patent Laid-Open Publication No. 2000-32999 discloses iron (III) chloride hexahydrate and hydrofluoric acid. A mixture of (HF) is disclosed.

However, such etching solutions known in the art have a problem that the etching rate with respect to the copper film and the other metal film is too fast, or the taper angle of the etched metal pattern exceeds about 90 °, that is, has an inverse taper shape. In addition, since hydrogen peroxide decomposes into water and oxidation due to disproportionation in the presence of copper ions and iron ions, heat is generated and rapid compositional changes result in low process margins and storage stability. In order to solve this problem, a hydrogen peroxide stabilizer is added to the etching solution together with hydrogen peroxide. However, since the price of the stabilizer is expensive, it causes a rise in production cost.

In particular, when the copper alloy film is etched using such etching solutions known in the art, the etching power of the etchant for each of the other metals included in the copper alloy film together with copper and copper is different, in particular, the copper alloy film Since the etch force for is excessively larger than the etch force for the copper film, the taper angle is lower than about 20 °, thereby causing a problem of performing a substantially poor etching process. In addition, when the taper angle becomes too low, there is a problem that the wiring resistance increases because the width of the wiring is substantially reduced.

Accordingly, the technical problem of the present invention was conceived in this respect, and an object of the present invention is to provide an etching solution composition with improved storage stability and process margin.

Another object of the present invention relates to a method of manufacturing a metal pattern having a stable tapered profile using the etchant composition.

Another object of the present invention relates to a method of manufacturing a display substrate using the etchant composition.

The etching liquid composition of the copper-based metal film according to the embodiment for achieving the above object of the present invention, 0.1% to 30% by weight of ammonium persulfate, 0.1% to 10% by weight of sulfate, 0.01% to 5% by weight of acetate % And 55% to 99.79% by weight of water.

In one embodiment, examples of the sulfate include calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate, sodium sulfate, and the like.

In one embodiment, examples of the acetate salt include ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate, magnesium acetate, and the like.

In one embodiment, the copper-based metal film may include a copper film and / or a copper-manganese alloy film.

In one embodiment, the etchant composition is 5% to 15% by weight of ammonium persulfate, 0.5% to 5% by weight of the sulfate, 0.1% to 3% by weight of the acetate, 77% by weight To 94.4 weight percent may be water.

A method of manufacturing a metal pattern according to an embodiment for realizing the object of the present invention described above is provided. In the above production method, a metal layer including a copper-manganese alloy film is formed on the substrate. A photoresist pattern is formed on the metal layer. By using the photoresist pattern as an etch stop layer, 0.1 wt% to 30 wt% of ammonium persulfate, 0.1 wt% to 10 wt% of sulfate, 0.01 wt% to 5 wt% of acetate, and 55 wt% to 99.79 wt% of water The metal pattern is formed by patterning the metal layer with an etchant composition.

In one embodiment, examples of the sulfate include calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate, sodium sulfate, and the like.

In one embodiment, examples of the acetate salt include ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate, magnesium acetate, and the like.

In one embodiment, the metal layer may further include a copper film formed under the copper-manganese alloy film.

In one embodiment, the metal layer may further include a titanium film formed under the copper film. In this case, the titanium film may be patterned by using a titanium metal etchant different from the etchant composition.

A method of manufacturing a display substrate according to an embodiment for realizing another object of the present invention described above is provided. In the above manufacturing method, a first metal layer is formed on the substrate. 0.1 wt% to 30 wt% ammonium persulfate, 0.1 wt% to 10 wt% sulfate, 0.01 wt% to 5 wt% acetate, and 55 wt% water using the photoresist pattern formed on the first metal layer as an etch stop layer The first metal layer is patterned with an etchant composition containing from 99.79 wt% to form a first electrode connected to the first signal line and the first signal line and a drain electrode spaced apart from the source electrode. A display substrate is manufactured by forming a pixel electrode in contact with the drain electrode.

In one embodiment, examples of the sulfate include calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate, sodium sulfate, and the like.

In one embodiment, examples of the acetate salt include ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate, magnesium acetate, and the like.

In one embodiment, the first metal layer may include a copper-manganese alloy film. In this case, a protective layer may be formed on the base substrate on which the drain electrode is formed to cover the first signal line, the source electrode, and the drain electrode and include silicon oxide.

In an embodiment, the first metal layer may further include a copper film formed under the copper-manganese alloy film.

In an embodiment, the first metal layer may further include a titanium film formed under the copper film. In this case, the first metal layer may be patterned by etching the copper layer and the copper-manganese alloy layer using the etchant composition and then etching the titanium layer using a titanium metal etchant. In this case, a protective layer including silicon oxide may be further formed under the titanium film.

In an embodiment, a semiconductor layer may be formed under the first metal layer. In this case, the photoresist pattern may include a first thickness portion and a second thickness portion thinner than the first thickness portion. Forming an electrode pattern connected to the first signal line and the first signal line using the photoresist pattern and the etchant composition, and patterning the semiconductor layer using the photoresist pattern and the electrode pattern as an etch stop layer An active pattern can be formed. Subsequently, the electrode pattern may be patterned using the residual photo pattern from which the second thickness portion is removed as an etch stop layer to expose the active pattern between the source electrode and the drain electrode.

In an embodiment, the semiconductor layer may include a metal oxide, and a protective layer covering the first signal line, the source electrode, and the drain electrode and including silicon oxide may be further formed on the base substrate on which the drain electrode is formed. Can be formed.

In example embodiments, the second metal layer including the copper layer may be patterned using the etchant composition to form a second signal line crossing the first signal line and a gate electrode connected to the second signal line.

According to such an etching liquid composition, a method of manufacturing a metal pattern, and a method of manufacturing a display substrate, a metal pattern having a stable tapered profile can be formed by using a non-aqueous etchant composition having improved storage stability and process margin. In particular, even if the metal pattern includes a copper-manganese alloy film, the metal pattern may have an excellent profile. The etchant composition may maintain storage stability for a long time without deteriorating the etching power. Accordingly, manufacturing reliability and productivity of the metal pattern and the display substrate including the same may be improved.

1 to 4 are cross-sectional views illustrating a method of forming a metal pattern according to an embodiment of the present invention.
5 is an electron scanning microscope of a metal pattern and a photoresist pattern including a copper film and a copper-manganese alloy film etched with the etching solution composition according to Examples 1 to 8 and the Comparative Example 1 to Comparative Example 4 of the present invention (Scanning electron microscope) The figure which showed the photographs.
6 is a view showing photographs of the storage stability evaluation test results of the etchant composition according to Example 1 of the present invention.
7 is a view showing photographs of the etching performance evaluation test results according to the contamination level of the etchant composition according to Example 1 of the present invention.
8 through 10 are cross-sectional views illustrating a method of manufacturing a display substrate according to another exemplary embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail preferred embodiments of the present invention.

1 to 4 are cross-sectional views illustrating a method of forming a metal pattern according to an embodiment of the present invention.

Referring to FIG. 1, a metal layer ML including a copper film 124 and a copper-manganese alloy film 126 is formed on a base substrate 110. The base substrate 110 may be a glass substrate including silicon oxide (SiOx). Each of the copper film 124 and the copper-manganese alloy film 126 may be continuously formed on the base substrate 110 using chemical vapor deposition.

The metal layer ML may further include a titanium film 122 formed between the copper film 124 and the base substrate 110. In this case, the titanium film 122 may also be formed using chemical vapor deposition. The titanium film 122 is a buffer layer that prevents the copper of the copper film 124 from contacting the copper film 124 and, in particular, diffuses into the metal oxide semiconductor and damages the pattern. It may be formed to a thickness of 300Å. Alternatively, when a pattern or a thin film containing silicon oxide is formed between the titanium film 122 and the base substrate 110, the titanium film 122 may be formed between the pattern or thin film and the copper film 124. It can suppress chemical reactions. Although not shown in the drawings, a plurality of patterns may be formed under the titanium film 122.

The copper film 124 is formed on the titanium film 122 and may be formed to a thickness of about 1,000 kPa to about 5,000 kPa. When the metal pattern MP (see FIG. 4) formed by patterning the metal layer ML applies a signal, the copper layer 124 may be a main line layer substantially applying the signal. have. The copper film 124 may be a substantially pure copper film, in which an amount of impurities is relatively less than that of copper.

The copper-manganese alloy film 126 is formed on the copper film 124 and may be formed to a thickness of about 100 kPa to about 300 kPa. The copper-manganese alloy film 126 is a metal film containing copper and manganese. For example, the copper-manganese alloy layer 126 may have an atomic ratio of about 1: 1 between copper and manganese. In the copper-manganese alloy film 126, when the copper film 124 is in direct contact with a pattern including silicon oxide, the copper of the copper film 124 may be chemically reacted with silicon oxide. 124 can be prevented from being altered.

2 to 4, the photoresist pattern 130 is formed on the metal layer ML, and the metal layer ML is etched using the photoresist pattern 130 as an etch stop layer. The copper-manganese alloy film 126 and the copper film 124 in the metal layer ML are 0.1% to 30% by weight of ammonium disulphate, 0.1% to 10% by weight of sulfate, and 0.01% to 5% of acetate. It is etched using an etchant composition comprising wt% and 55 wt% to 99.79 wt% of water. By the etchant composition, the copper-manganese alloy film 126 and the copper film 124 may be etched over time. The etchant composition is a composition for etching a copper-based metal film including a pure copper film or a copper alloy film. Therefore, even when the metal layer ML includes the titanium film 122, the titanium film 122 is removed using a separate titanium metal etchant.

Subsequently, the titanium film 122 exposed after the copper-manganese alloy film 126 and the copper film 124 are etched may be etched to form the metal pattern MP illustrated in FIG. 4.

The photoresist pattern 130 may be formed using a positive photoresist composition. Alternatively, the photoresist pattern 130 may be formed using a negative photoresist composition.

Etching of the metal layer ML may be performed according to a method known in the art, for example, by providing the etchant composition and the titanium metal etchant to the metal layer ML by an immersion method or a spray method. The metal layer ML may be etched. For example, the etching process of the metal layer ML may be performed at about 30 ° C. to about 33 ° C., and may be performed for about 50 seconds to about 150 seconds.

In the etchant composition, ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ , ammonium persulfate) is an oxidant which is an etching main component for etching the copper film 124 and the copper-manganese alloy film 126. Ammonium persulfate may have purity for semiconductor processing. Ammonium persulfate etches the copper-manganese alloy film 126 and the copper film 124 by a reaction as in Scheme 1 below to form a stable compound.

<Scheme 1>

S ₂ O ₈ ^2- + Cu + Mn → CuSO ₄ + MnSO ₄

With respect to the total weight of the etchant composition, when the content of ammonium persulfate is less than about 0.1 wt%, the copper-manganese alloy film 126 and the copper film 124 may not be etched. In addition, when the content of ammonium persulfate is more than about 30% by weight, the etching process of the copper-manganese alloy film 126 and the copper film 124 is too fast to control the etching process. Therefore, the content of ammonium persulfate is preferably from about 0.1% to about 30% by weight based on the total weight. More preferably, the content of ammonium persulfate can stably etch the copper-manganese alloy film 126 and the copper film 124 at about 5% to about 15% by weight based on the total weight.

The sulfate is an auxiliary oxidant for etching the copper-manganese alloy film 126 and the copper film 124, and serves to control the etching rate of the etchant composition. The sulphate may participate in the reaction of copper and / or manganese with formula 1 by generating sulfate ions (SO ₄ ^2- ). The sulfate may be used having a purity for the semiconductor process.

Specific examples of the sulfate include ammonium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, copper sulfate, magnesium sulfate, zinc sulfate, iron sulfate, and the like. These may be used alone or in combination of two or more. In particular, ammonium sulfate, potassium sulfate or sodium sulfate is preferably used as the auxiliary oxidant.

When the content of the sulfate is less than about 0.1% by weight based on the total weight, the etching rate may not be adjusted. When the content of the sulfate is greater than about 10% by weight, the etching of the copper-manganese alloy film 126 is excessively accelerated so that the etching surface of the copper-manganese alloy film 126 and the surface of the base substrate 110 are The resulting angle may be excessively small (about 10 ° to about 15 °) or a pattern short may occur. Therefore, the content of the sulfate is preferably about 0.1% to about 10% by weight. More preferably, the amount of sulfate may be about 0.5% to about 5% by weight.

The acetate salt is an auxiliary oxidant for etching the copper-manganese alloy film 126 and the copper film 124, and reduces the taper angle θ of the metal pattern MP by controlling the etching rate of the etchant composition. Can be prevented. The taper angle θ of the metal pattern MP may be defined as an acute angle formed between the surface of the base substrate 110 and the side surface of the metal pattern MP. The acetate may adjust the taper angle θ to about 45 ° to about 75 ° together with ammonium persulfate and the sulfate.

The acetate salt is a compound that can be dissociated into acetate ions (CH ₃ COO ⁻ ). As the acetate salt, those having a purity for a semiconductor process can be used. Specific examples of the acetate salts include ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate and the like. Preferably, as the acetate salt, ammonium acetate, sodium acetate or potassium acetate can be used.

When the content of the acetate salt is less than about 0.01% by weight based on the total weight, the etching rate cannot be controlled and the etching rate becomes too fast. Accordingly, the taper angle θ may be less than about 15 °. On the other hand, when the content of the acetate is more than about 5% by weight based on the total weight, the etching of the copper-manganese alloy film 126 and the copper film 124 is uneven or rather can not be etched. Thus, the content of acetate is preferably about 0.01% to about 5% by weight based on the total weight. More preferably, the content of acetate may be about 0.01% to about 3% by weight.

Water may be added to ammonium disulphate peroxide, the sulfate and the acetate to define the total weight of the etchant composition as about 100%. That is, the excess water in the present invention is about 55% to about 99.79% by weight. As water used in the present invention, water for semiconductors, ultrapure water, or the like can be used.

Referring back to FIG. 2, when the metal layer ML is etched using the etchant composition, the copper-manganese alloy layer 126 disposed above the metal layer ML is etched first. Since the portion of the copper-manganese alloy layer 126 on which the photoresist pattern 130 is formed is not exposed to the etchant composition, the portion of the copper-manganese alloy layer 126 is not etched by the etchant composition and remains on the base substrate 110.

Referring to FIG. 3, as the metal layer ML is exposed to the etchant composition, the copper layer 124 exposed by the removal of the copper-manganese alloy layer 126 is etched. In this case, the copper-manganese alloy layer 126 may be partially etched while the copper layer 124 is etched due to the wet etching using the etchant composition.

Referring to FIG. 4, the titanium pattern 122 exposed by etching of the copper-manganese alloy layer 126 and the copper layer 124 is etched by the titanium metal etchant to form the metal pattern MP. Form. By forming the metal pattern MP using the etchant composition, the taper angle θ of the metal pattern MP may be about 45 ° to about 75 °. The metal pattern MP may include a first pattern including the copper layer 124 and the copper-manganese alloy layer 126, and a second layer including the titanium layer 122 formed below the first pattern. When dividing into patterns, the taper angle θ of the metal pattern MP may be substantially the same as the first slope of the etching surface of the first pattern with respect to the surface of the base substrate 110. In addition, the taper angle θ of the metal pattern MP may be substantially the same as the second slope of the etching surface of the second pattern. Hereinafter, the first slope will be described as a taper angle θ of the metal pattern MP.

Meanwhile, in order to completely remove the metal layer ML on the base substrate 110 outside the region where the photoresist pattern 130 is formed, the metal layer ML is excessively etched for a longer time than the etching end point. Can be. The etching endpoint may be defined as a time when the metal layer ML is removed to expose the surface of the base substrate 110. By over-etching the metal layer ML, a skew length Xs, which is a distance between a side of the metal pattern MP and a side of the photoresist pattern 130 may be greater than about 0 μm.

Hereinafter, the etching solution composition according to the present invention will be described in more detail through the etching solution composition according to Examples 1 to 8 and the etching solution composition according to Comparative Example 1.

Preparation of Examples 1 to 8 and Comparative Example 1

The etchant compositions according to Examples 1 to 8 of the present invention and the etchant composition according to Comparative Example 1 were prepared as shown in Table 1 below. In Table 1, the unit indicating the content of each component represents "wt%" in which the total weight of the etching liquid composition is 100%, and "APS" represents ammonium persulfate.

TABLE 1

Preparation of Samples 1-8 and Comparative Samples 1-4

A titanium film, a copper film, and a copper-manganese alloy film were sequentially formed on the glass substrate through chemical vapor deposition. In the copper-manganese alloy film, the atomic ratio of copper to manganese was 50:50. The thickness of the titanium film was about 100 kPa to about 300 kPa, the thickness of the copper film was about 1,000 kPa to about 5,000 kPa, and the thickness of the copper-manganese alloy film was about 100 kPa to about 300 kPa. Subsequently, a photoresist layer was formed on the copper-manganese alloy film, and the photoresist layer was exposed and developed to form a photoresist pattern. Sample 1 including the metal pattern by etching the copper-manganese alloy film and the copper film using a etching liquid composition according to Example 1 of the present invention at about 30 ° C using the photoresist pattern as an etch stop layer in a spray method Prepared. In this case, the copper-manganese alloy film and the copper film was etched by about 60% excess with respect to the etching end point (etching end point) in the etching liquid composition according to Example 1 of the present invention to prepare the metal pattern. Excess etch of about 60% was performed for about 130 seconds, about 1.6 times the time defining the etch endpoint.

Samples 2 to 8 were prepared using the etchant compositions according to Examples 2 to 8 of the present invention through substantially the same process as Sample 1, and comparative samples using the etchant compositions according to Comparative Examples 1 to 4 1 to 4 were prepared.

Etch Characteristic Evaluation

Profiles of the metal patterns and photoresist patterns of Samples 1 to 8 and Comparative Samples 1 to 4 prepared by using the etchant compositions according to Examples 1 to 8 and Comparative Examples 1 to 4 of the present invention were manufactured by Hitachi. It photographed using S-4200 (model name) which is a scanning electron microscope (SEM) of the company, a company name, Japan. The results are shown in Figure 5 and Table 2.

TABLE 2

The skew length in Table 2 means the distance between the end of the metal pattern and the end of the photoresist pattern. In the skew length of Table 2, "◎" represents a range of skew length of about 0.45 µm or more and less than about 0.75 µm, and "o" represents a range of skew length of about 0.15 µm or more and less than about 0.45 µm, Represents a skew length of at least about 0.75 μm.

In addition, in the taper angle of Table 2, "(circle)" represents the range of a taper angle of about 50 degrees or more and less than about 60 degrees, and "(circle)" represents the range of a taper angle of about 40 degrees or more and less than about 50 degrees, " x "indicates the taper angle is less than about 40 °.

5 is an electron scanning microscope of a metal pattern and a photoresist pattern including an etching solution composition according to Examples 1 to 8 of the present invention and a copper film and a copper-manganese alloy layer etched with the etching solution composition according to Comparative Examples 1 to 4 (SEM) The figure which shows the photographs.

5 and Table 2, the etching surface of the metal pattern in each of Samples 1 to 8 is based on the surface of the glass substrate, the acute angle formed by the etching surface and the surface, that is, the taper angle is about 40 ° to about It can be seen that it is about 60 °.

On the other hand, in Comparative Sample 1, the etching surface of the metal pattern may have a taper angle of about 30 ° based on the surface of the glass substrate. In the case of the comparative sample 2, it can be seen that the skew length and the taper angle are excellent compared to the samples 1 to 8. However, in the case of Comparative Sample 2, the etching rate of the copper film and the copper-manganese alloy film is significantly slowed to about 100 seconds or more, thereby increasing the overall process time. In the case of Comparative Sample 3, the skew length is good while the taper angle is remarkably low. In the case of Comparative Sample 4, both the skew length and the taper angle are poor.

Thus, through Samples 1 through 8 and Comparative Samples 1 through 4, ammonium persulfate 0.1% to 30%, sulfates 0.1% to 10%, acetates 0.01% to 5%, and water 55 When the etching liquid composition including the wt% to 99.79 wt% is used, it can be seen that the taper angle of the metal pattern including the copper film and the copper-manganese alloy film may be formed at about 40 ° to about 60 °. Even when the titanium film is patterned by using the dual structure metal pattern and the photo pattern as an etch stop layer, the total taper angle of the metal pattern including the titanium layer is formed to be about 40 ° to about 60 ° by the double structure metal pattern. Can be.

On the other hand, referring to Table 2, it can be seen that the skew length of Samples 1 to 8 has an appropriate level compared to the skew length of Comparative Sample 1.

Storage stability assessment

Sample 9 was prepared through a process substantially the same as the process of preparing sample 1 using the etchant composition according to Example 1 of the present invention stored at about 25 ° C. The etch endpoint, skew length and taper angle for Sample 9 were measured and SEM pictures were obtained. The results are shown in Table 3 and FIG. 6.

Etch solution composition according to Example 1 of the present invention stored for about 3 days at room temperature about 25 ℃, etchant composition according to Example 1 of the present invention stored for about 6 days, about 9 days, about 12 days and about 15 days Samples 10 to 14 were prepared through substantially the same processes as those for preparing Sample 9 using each. The etch endpoint, skew length and taper angle for each of Samples 10-14 were measured and SEM pictures were obtained. The results are shown in Table 3 and FIG. 6.

TABLE 3

In Table 3, the etching endpoint is visually observed that both the copper-manganese alloy film and the copper film, which are not covered by the photoresist pattern, are etched based on the point at which the etching liquid composition contacts the copper-manganese alloy film in the triple layer. It is defined as the time until the confirmed point.

6 is a view showing photographs of the storage stability evaluation test results of the etchant composition according to Example 1 of the present invention.

Referring to Figure 6 and Table 3, the etchant composition according to Example 1 of the present invention can be seen that almost no change in the etching characteristics until about 12 days of room temperature storage. That is, it can be seen that the etching solution composition according to the present invention can maintain the initial etching performance even if stored at room temperature.

Evaluation of substrate processing capacity

After adding about 100 ppm of copper powder to the etchant composition according to Example 1 of the present invention, the copper powder was dissolved for about 3 hours. Using the etching solution composition in which the copper powder is dissolved, a titanium film of about 100 kPa to about 300 kPa, a copper film of about 1,000 kPa to about 5,000 kPa, and a copper-manganese alloy film of about 100 kPa to about 300 kPa are used as a photoresist pattern as an etch stop layer After etching, the profile of the formed pattern was analyzed using a field emission scanning electron microscope (FE-SEM).

Subsequently, about 100 ppm was further dissolved in the etching liquid composition in which the copper powder was dissolved at about 100 ppm, and the process was repeatedly performed until the total amount of the copper powder was about 400 ppm. The results are shown in Table 4 and FIG.

TABLE 4

7 is a view showing photographs of the etching performance evaluation test results according to the contamination level of the etchant composition according to Example 1 of the present invention.

Referring to Table 4 and Figure 7, it can be seen that the etching liquid composition according to Example 1 of the present invention does not change the etching characteristics until the concentration of copper ions is about 300 ppm. Through this, even if the etching process is performed on a plurality of substrates on which the titanium film, the copper film and the copper-manganese alloy film are formed, it can be seen that the initial etching characteristics of the etchant composition can be maintained. In other words, it can be seen that the substrate has good processing capability.

8 through 10 are cross-sectional views illustrating a method of manufacturing a display substrate according to another exemplary embodiment of the present invention.

Referring to FIG. 8, a gate electrode GE is formed on a base substrate 210, and an insulating layer 230, a semiconductor layer 240, and a gate electrode GE are formed on the base substrate 210 on which the gate electrode GE is formed. The data metal layer 250 is sequentially formed.

The gate electrode GE may have a single metal film or a multiple metal film structure including two or more metal films. The gate electrode GE is connected to a gate line, which is a signal line extending along one direction of the base substrate 210.

The insulating layer 230 covers the base substrate 210 on which the gate line and the gate electrode GE are formed. The insulating layer 230 may be formed of silicon oxide to prevent deterioration of the semiconductor layer 240.

The semiconductor layer 240 is formed on the base substrate 110 on which the insulating layer 230 is formed, and includes a metal oxide having a higher electron mobility than amorphous silicon. The metal oxide is an oxide semiconductor, and may be a mono-type oxide including a single metal or a multi-element oxide including two or more different metals.

The data metal layer 250 includes a titanium film 252, a copper film 254, and a copper-manganese alloy film 256 sequentially formed on the semiconductor layer 240. The titanium film 252 may have a thickness of about 100 kPa to about 300 kPa. The copper film 254 may have a thickness of about 1,000 kPa to about 5,000 kPa, and the copper-manganese alloy film 256 may have a thickness of about 100 kPa to about 300 kPa.

A photoresist pattern 300 is formed on the data metal layer 250. The photoresist pattern 300 may be formed by coating, exposing and developing a positive or negative photoresist composition. The photoresist pattern 300 may include a first thickness portion 310 having a first thickness and a second thickness portion 320 having a second thickness that is thinner than the first thickness. The first thickness part 310 is formed in an area where the data metal layer 250 remains, and the photoresist pattern 300 is not formed in an area where the data metal layer 250 is removed. In this case, the second thickness part 320 is formed on an area of the region in which the data metal layer 250 is removed to form a channel part of the thin film transistor SW (see FIG. 9).

By using the photoresist pattern 300 as an etch stop layer, the data metal layer 250 is first etched with the first etchant composition to be connected to the electrode pattern remaining under the photoresist pattern 300 and the electrode pattern. As a signal wiring, a data line crossing the gate line is formed. The first etchant composition may be a per water-based etchant including hydrogen peroxide, or a non-water-based etchant including ammonium persulfate as a main oxidizing agent. In the first etching process, the copper film 254 and the copper-manganese alloy film 256 are etched using a copper-based metal etchant, and the titanium film 252 is a titanium metal different from the copper-based metal etchant. It can be etched using an etchant. Alternatively, the titanium film 252, the copper film 254, and the copper-manganese alloy film 256 may be collectively etched using an integrated etchant composition.

An active pattern AP is formed by etching the semiconductor layer 240 using the photoresist pattern 330 and the electrode pattern as an etch stop layer. A dummy pattern in which the semiconductor layer 240 is patterned may also be formed under the data line.

Referring to FIG. 9, the second thickness part 320 is removed from the base substrate 210 on which the data line and the electrode pattern are formed to form a residual photo pattern 330. The remaining photo pattern 330 may be formed by removing the entire thickness of the photoresist pattern 300 by the second thickness of the second thickness part 320. The electrode pattern is partially exposed by the residual photo pattern 330.

Subsequently, the source photo SE and the drain electrode DE of the thin film transistor SW are formed by using the residual photo pattern 330 as an etch stop layer and etching the electrode pattern with a second etchant composition. The source electrode SE is connected to the data line, and a portion of the electrode pattern is removed to separate the source electrode SE from the drain electrode DE. The active pattern AP is partially exposed between the source electrode SE and the drain electrode DE. The exposed active pattern AP between the source electrode SE and the drain electrode DE becomes the channel CH of the thin film transistor SW.

The second etchant composition comprises 0.1% to 30% by weight of ammonium persulfate, 0.1% to 10% by weight of sulfate, 0.01% to 5% by weight of acetate, and 55% to 99.79% by weight of water. Preferably, the etchant composition comprises about 5% to about 15% by weight of ammonium persulfate, about 0.5% to about 5% by weight of the sulfate, about 0.5% to about 5% by weight of the acetate and water 55 weight percent to 99.79 weight percent. Since the second etchant composition is substantially the same as that described in the etchant composition of the present invention and the method of forming the metal pattern using the same, detailed descriptions thereof will be omitted. The first etchant composition may also be substantially the same as the second etchant composition. The second etchant composition may stably remove the copper-manganese alloy film 256 and the copper film 254.

Meanwhile, in order to minimize the data metal layer 250 remaining in the second etching liquid composition except the region where the residual photo pattern 330 is formed, the data metal layer 250 is excessively longer than the time of the etching end point. It can be etched. By using the second etchant composition, even if the electrode pattern is excessively etched, the taper angle θ of each of the source electrode SE and the drain electrode DE may be included within a stable range of about 40 ° to about 60 °. have.

Subsequently, after the channel CH is formed by removing the titanium film 252 of the electrode pattern using the titanium metal etchant, the residual photo pattern 330 is removed.

Referring to FIG. 10, a protective layer 260 is formed on the base substrate 110 on which the data line, the source electrode SE, and the drain electrode DE are formed. The protective layer 260 includes silicon oxide. The copper-manganese alloy film 256 may prevent the copper film 254 from being deteriorated by the contact between the protective layer 260 and the copper film 254. In addition, since the protective layer 260 includes silicon oxide, it is possible to prevent the semiconductor layer 240 from being deteriorated by the protective layer 260 in a portion in contact with the active pattern AP.

Subsequently, a hole exposing the drain electrode DE is formed in the passivation layer 260, and a pixel electrode PE is formed on the passivation layer 260 in which the hole is formed. The pixel electrode PE is connected to the thin film transistor SW by contacting the drain electrode DE.

Accordingly, the display substrate 200 including the oxide semiconductor thin film transistor SW may be manufactured.

Although not illustrated, an ohmic contact layer may be further formed on the semiconductor layer 240 to reduce contact resistance between the semiconductor layer 240 and the source and drain electrodes SE and DE. An additional metal layer further formed below the titanium layer 252 or the titanium layer 252 of the data metal layer 250 may provide a contact resistance between the active pattern AP and the source and drain electrodes SE and DE. It can act as a reducing ohmic contact pattern.

Meanwhile, when the gate metal layer forming the gate electrode GE has a multilayer structure including a copper film and a copper-manganese alloy film formed on the copper film, the second etchant for etching the data metal layer 250. The gate metal layer may be etched using the composition. Even if the gate metal layer is overetched using the second etchant composition, the taper angle of the gate electrode GE may be included in a stable range.

As described above, a profile of the source electrode SE, the drain electrode DE, and the data line may be stably formed by using the etchant composition in the process of etching the data metal layer 250. . In particular, since the taper angle of each of the source electrode SE, the drain electrode DE, and the data line may be formed to have about 40 ° to about 60 °, the protection formed thereafter by the step difference therebetween. The short circuit of the layer 260 and the pixel electrode PE may be prevented, thereby improving manufacturing reliability of the display substrate 200.

In another embodiment, in the case of a display substrate including a thin film transistor having a top-gate structure in which a gate electrode is formed on an oxide semiconductor pattern, a source electrode, and a drain electrode, the etching solution in the process of forming the source electrode and the drain electrode. By etching the data metal layer using the composition, it is possible to prevent the gate electrode and the pixel electrode from being short-circuited by the step difference between the source electrode and the drain electrode. The top-gate thin film transistor may include an oxide semiconductor pattern formed on a glass substrate, source and drain electrodes formed on the oxide semiconductor pattern, and a gate electrode overlapping each of the source and drain electrodes. have. In this case, the oxide semiconductor pattern and the source and drain electrodes may be formed using the second etchant composition as one photoresist pattern similar to that described with reference to FIG. 9.

As described above in detail, a metal pattern having a stable tapered profile may be formed by using the non-fruited etchant composition having improved storage stability and process margin. In particular, even if the metal pattern includes a copper-manganese alloy film, the metal pattern may have an excellent profile. The etchant composition may maintain storage stability for a long time without deteriorating the etching power. Accordingly, manufacturing reliability and productivity of the metal pattern and the display substrate including the same may be improved.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

110 and 210: base substrates 122 and 252: titanium film
124 and 254 copper films 126 and 256 copper-manganese alloy films
130 and 300 photoresist patterns 310 and 320: first and second thickness portions
330: residual photo pattern AP: active pattern
230: insulating layer 260: protective layer

Claims (14)

5 wt% to 15 wt% ammonium persulfate;
Sulfate from 0.7% to 5% by weight;
0.1 wt% to 3 wt% acetate; And
The etching liquid composition of the copper-type metal film which consists of excess water. The method of claim 1, wherein the sulfate
An etching solution composition comprising at least one selected from the group consisting of calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate and sodium sulfate. The method of claim 1, wherein the acetate salt
An etchant composition comprising at least one selected from the group consisting of ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate, and magnesium acetate. The etchant according to any one of claims 1 to 3, wherein the copper-based metal film includes a copper-manganese alloy film, and the atomic ratio of copper and manganese in the copper-manganese alloy film is 50:50. Composition. Forming a metal layer comprising a copper-manganese alloy film on the substrate;
Forming a photoresist pattern on the metal layer; And
Using the photoresist pattern as an etch stop layer, the metal layer is formed of an etchant composition including 5 wt% to 15 wt% of ammonium persulfate, 0.7 wt% to 5 wt% of sulfate, 0.1 wt% to 3 wt% of acetate, and excess water. A method of forming a metal pattern comprising patterning. The method of claim 5, wherein the sulfate
A method of forming a metal pattern comprising at least one selected from the group consisting of calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate and sodium sulfate. The method of claim 5, wherein the acetate salt
A method of forming a metal pattern comprising at least one selected from the group consisting of ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate and magnesium acetate. The method of claim 5, wherein the atomic ratio of copper to manganese in the copper-manganese alloy film is 50:50. Forming a first metal layer comprising a copper-manganese alloy film on the substrate;
By using the photoresist pattern formed on the first metal layer as an etch stopper film, it is composed of 5% to 15% by weight of ammonium persulfate, 0.7% to 5% by weight of sulfate, 0.1% to 3% by weight of acetate and excess water Patterning the first metal layer with an etchant composition to form a source electrode connected to the first signal line and the first signal line and a drain electrode spaced apart from the source electrode; And
Forming a pixel electrode in contact with the drain electrode. The method of claim 9, wherein the sulfate
A method for producing a display substrate, comprising at least one selected from the group consisting of calcium sulfate, barium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, iron sulfate, zinc sulfate, copper sulfate, and sodium sulfate. The method of claim 9, wherein the acetate salt
A method of manufacturing a display substrate comprising at least one selected from the group consisting of ammonium acetate, sodium acetate, potassium acetate, calcium acetate, aluminum acetate, zinc acetate, tin acetate and magnesium acetate. The method of claim 9, wherein the atomic ratio of copper to manganese in the copper-manganese alloy film is 50:50. The method of claim 9, wherein the first metal layer further comprises a copper film formed under the copper-manganese alloy film. The method of claim 13, wherein the first metal layer further comprises a titanium film formed under the copper film,
Forming the drain electrode
Etching the copper film and the copper-manganese alloy film with the etchant composition; And
And etching the titanium film using a titanium metal etchant.

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