Silicon etchant composition, pattern formation method and manufacturing method of array substrate using the etchant composition, and array substrate manufactured therefrom

Abstract

The present disclosure relates to a silicon etchant composition comprising (A) an alkaline compound, (B) a metal salt, and (C) water, a pattern formation method and a manufacturing method of an array substrate using the silicon etchant composition, and an array substrate manufactured therefrom.

Claims

1. A silicon etchant composition, comprising an alkaline compound, a metal salt, and water, wherein the metal salt is in an amount of 0.1 to 1.5% by weight relative to a total weight of the silicon etchant composition, wherein an etch selectivity according to Equation 1 is equal to or greater than 10,000 when etching a silicon film and a silicon oxide film using the silicon etchant composition, $\begin{array}{cc}\frac{\mathrm{Etch}\mathrm{rate}\mathrm{of}\mathrm{silicon}\mathrm{film}}{\mathrm{Etch}\mathrm{rate}\mathrm{of}\mathrm{silicon}\mathrm{oxide}\mathrm{film}}=\mathrm{Etch}\mathrm{selectivity},& \left[\mathrm{Equation}1\right]\end{array}$ wherein the metal salt is one or more of aluminum hydroxide, aluminum acetate, iron chloride, and titanium chloride.

2. The silicon etchant composition of claim 1, wherein the silicon etchant composition comprises 1 to 23% by weight of the alkaline compound relative to the total weight of the silicon etchant composition.

3. The silicon etchant composition of claim 1, wherein the alkaline compound includes organic hydroxide, inorganic hydroxide, or an azabicyclo-type compound, wherein the azabicyclo-type compound comprises one or more selected from the group consisting of an azabicyclo compound, a diazabicyclo compound, and a triazabicyclo compound.

4. The silicon etchant composition of claim 3, wherein the organic hydroxide comprises a quaternary alkylammonium compound.

5. The silicon etchant composition of claim 3, wherein the inorganic hydroxide is one or more selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and francium hydroxide.

6. The silicon etchant composition of claim 1, further comprising one or more additives selected from powdered silicon, a compound represented by Formula 2, and an alkanolamine-based compound ##STR00003## wherein R.sub.1 to R.sub.4 are each independently a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, an acetate group having 1 to 5 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an alkyl group having 1 to 5 carbon atoms that is unsubstituted or substituted with one or more of a hydroxyl group, an alkoxy group, and an amino group, and at least one of R.sub.1 to R.sub.4 includes a hydroxyl group or an alkoxy group.

7. The silicon etchant composition of claim 6, wherein the alkanolamine-based compound is one selected from the group consisting of 1-amino-2-propanol, 2-amino-1-butanol, 3-amino-1-propanol, 3-amino-1,2-propanediol, methyldiethanolamine, propanolamine, ethanolamine, diethanolamine, N-methylethanolamine, N-methyldiethanolamine, 2-amino-3-methyl-1-butanol, 3-amino-2,2-dimethyl-1-propanol, tris(hydroxymethyl)aminomethane, 1,3-diamino-2-propanol, 2-amino-2-methyl-1,3-propanediol, 3-methylamino-1-propanol, 2-dimethylamino-2-methyl-1-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino-1-propanol, 2-dimethylamino-1-propanol, 2-diethylamino-1-propanol, 2-diethylamino-1-ethanol, 2-ethylamino-1-ethanol, 1-(dimethylamino)2-propanol, diethanolamine N-propyldiethanolamine, N-isopropyldiethanolamine; N-(2-methylpropyl) diethanolamine, N-n-butyldiethanolamine, N-t-butylethanolamine, N-cyclohexyldiethanolamine, 2-(dimethylamino)ethanol; 2-diethylaminoethanol, 2-dipropylaminoethanol, 2-butylaminoethanol, 2-t-butylaminoethanol, 2-cycloaminoethanol, 2-amino-2-pentanol, 2-[bis(2-hydroxyethyl)amino]-2-methyl-1-propanol, 2-[bis(2-hydroxyethyl)amino]-2-propanol, N,N-bis(2-hydroxypropyl)ethanolamine, 2-amino-2-methyl-1-propanol triisopropanolamine, and combinations thereof.

8. The silicon etchant composition of claim 6, wherein the powdered silicon includes silicon or a structure in which a silicon oxide film is formed on the surface.

9. A pattern formation method, comprising: forming a silicon film on a substrate; and etching the silicon film using the silicon etchant composition of claim 1.

10. A manufacturing method of an array substrate, comprising the pattern formation method of claim 9.

Description

EXAMPLES AND COMPARATIVE EXAMPLES: PREPARATION OF A SILICON ETCHANT COMPOSITION

(1) The silicon etchant compositions according to Examples and Comparative Examples were prepared with reference to Tables 1 and 2 below.

(2) TABLE-US-00001 TABLE 1 (Unit: % Alkaline compound Metal salt Additive by weight) A-1 A-2 A-3 B-1 B-2 B-3 B-4 C-1 C-2 D-1 D-2 Water Example 1 10 0.1 Balance Example 2 20 0.1 Balance Example 3 1 0.1 Balance Example 4 15 0.1 Balance Example 5 10 0.01 Balance Example 6 10 0.5 Balance Example 7 10 1 Balance Example 8 10 0.1 0.05 Balance Example 9 10 0.1 0.1 Balance Example 10 10 0.1 1 Balance Example 11 10 0.1 1 Balance Example 12 10 0.1 10 Balance Example 13 10 0.1 20 Balance Example 14 10 0.1 1 10 Balance Example 15 23 0.1 Balance Example 16 23 0.1 1 Balance Example 17 23 0.1 10 Balance Example 18 23 0.1 1 10 Balance Example 19 10 1.5 Balance Example 20 10 1.5 1 Balance Example 21 10 1.5 10 Balance Example 22 10 2.0 1 10 Balance Example 23 10 0.1 0.03 Balance Example 24 10 0.1 1.5 Balance Example 25 10 0.1 0.5 Balance Example 26 10 0.1 23 Balance

(3) TABLE-US-00002 TABLE 2 Alkaline compound Inorganic salt Additive (Unit: % by weight) A-1 A-2 A-3 B-1 E-1 E-2 C-1 D-1 Water Comp. Example 1 10 0.1 Balance Comp. Example 2 10 0.1 1 Balance Comp. Example 3 10 0.1 10 Balance Comp. Example 4 10 0.1 1 10 Balance Comp. Example 5 10 0.1 Balance Comp. Example 6 10 0.1 1 Balance Comp. Example 7 10 0.1 10 Balance Comp. Example 8 10 0.1 1 10 Balance Comp. Example 9 10 Balance Comp. Example 10 20 Balance Comp. Example 11 1 Balance Comp. Example 12 10 1 Balance Comp. Example 13 10 10 Balance Comp. Example 14 10 1 10 Balance Comp. Example 15 0.1 1 Balance Comp. Example 16 0.1 10 Balance Comp. Example 17 0.1 1 10 Balance Comp. Example 18 0.1 Balance Comp. Example 19 1 Balance Comp. Example 20 10 Balance
<Alkaline Compound> A-1: Tetramethylammonium hydroxide A-2: 1,8-diazabicyclo [5.4.0]undec-7-ene A-3: Sodium hydroxide
<Metal Salt> B-1: Aluminum hydroxide B-2: Aluminum acetate B-3: Iron chloride B-4: Titanium chloride
<Silicon-Based Compound> C-1: Powdered silicon (size <100 nm) C-2: Tetraethoxysilane
<Alkanolamine Compound> D-1: 1-amino-2-propanol D-2: 2-amino-1-butanol
<Inorganic Salt> E-1: Sodium acetate E-2: Potassium chloride

Experimental Example

(4) For the etchant compositions according to the Examples and Comparative Examples, performance evaluation was performed as follows.

(5) Evaluation 1: Evaluation of Etch Rate to Silicon Film

(6) Specimens were prepared by cutting a wafer on which silicon was deposited at a thickness of 6000 on a silicon wafer into a size of 1.51.5 cm. The specimens were immersed in the etchant compositions of the Examples and Comparative Examples under the condition of 80 C. and 400 rpm for 30 seconds. Then, the specimens were taken out, washed with water, and then dried using air. Thereafter, the thickness of each silicon film was measured using an ellipsometer, and the etch rate of each silicon film was calculated with change values in the thickness of each film. In this case, the etch rate was evaluated based on the following criteria, and the results are shown in Tables 3 and 4 below.

(7) <Evaluation Criteria>

(8) : etch rate of 4500 /min or more : etch rate less than 4500 /min and more than or equal to 3500 /min : etch rate less than 3500 /min and more than or equal to 2500 /min X: etch rate less than 2500 /min
Evaluation 2: Evaluation of Etch Selectivity of Silicon Film/Silicon Oxide Film

(9) Specimens were prepared by cutting the silicon oxide film into a size of 1.51.5 cm. The specimens were immersed in the etchant compositions of the Examples and Comparative Examples under the condition of 80 C. and 400 rpm for 10 minutes. Then, the specimens were taken out, washed with water, and then dried using air. Thereafter, the thicknesses of the silicon oxide films were measured using an ellipsometer, and the etch rates were calculated with changes in the thickness before and after etching. In this case, the etch rate of the silicon film (measured in the Evaluation 1) and the etch rate of the silicon oxide film were substituted into Equation 1 below and converted into an etch selectivity. Evaluation was performed according to the following criteria, and the results are shown in Tables 3 and 4 below.

(10) $\begin{array}{cc}\frac{\mathrm{Etch}\mathrm{rate}\mathrm{of}\mathrm{silicon}\mathrm{film}}{\mathrm{Etch}\mathrm{rate}\mathrm{of}\mathrm{silicon}\mathrm{oxide}\mathrm{film}}=\mathrm{Etch}\mathrm{selectiviy}& \left[\mathrm{Equation}1\right]\end{array}$
<Evaluation Criteria> : etch selectivity of 15000 or more : etch selectivity more than or equal to 10000 and less than 15000 : etch selectivity more than or equal to 5000 and less than 10000 X: etch selectivity less than 5000
Evaluation 3: Evaluation of Surface Roughness of Silicon Film

(11) After the etching was evaluated, the surface roughness of the silicon film and the silicon oxide film wafer pieces was measured using atomic force microscopy (AFM). In this case, the surface roughness was evaluated according to the following criteria, and the results are shown in Tables 3 and 4 below.

(12) <Evaluation Criteria>

(13) : 10 or less : less than or equal to 20 and more than 10 : less than or equal to 50 and more than 20 X: more than 50
Evaluation 4: Evaluation of Mixing Stability of Etchant Composition

(14) Since the composition is a mixture of inorganic salts and organic materials, if each component remains undissolved or recrystallized, it may act as an impurity during etching of the silicon film. In order to confirm this, mixing stability was evaluated by performing light transmittance analysis of the composition with UV-Vis spectroscopy equipment. In this case, mixing stability (light transmittance) was evaluated according to the following criteria, and the results are shown in Tables 3 and 4 below.

(15) <Evaluation Criteria>

(16) : 100% : less than 100% and more than or equal to 98% : less than 98% and more than or equal to 95% X: less than 95%

(17) TABLE-US-00003 TABLE 3 Etch Surface rate of Etch roughness Mixing silicon selectivity of silicon stability Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Example 24 Example 25 Example 26

(18) TABLE-US-00004 TABLE 4 Etch Surface rate of Etch roughness Mixing silicon selectivity of silicon stability Comp. X Example 1 Comp, X Example 2 Comp. X Example 3 Comp. X Example 4 Comp. X Example 5 Comp, X Example 6 Comp. X Example 7 Comp. X Example 8 Comp. X Example 9 Comp. X Example 10 Comp. X Example 11 Comp. X Example 12 Comp. X Example 13 Comp. X Example 14 Comp. X X X Example 15 Comp. X X Example 16 Comp. X X X Example 17 Comp. X X Example 18 Comp. X X X Example 19 Comp. X X Example 20

(19) In the present Experimental Example, evaluation was performed in terms of etch rate of silicon, etch selectivity, surface roughness of silicon, and mixing stability for the etchant compositions according to Examples and Comparative Examples of the present disclosure.

(20) It could be confirmed that the etchant composition containing the alkaline compound and the metal salt according to the present disclosure had the corrosion resistance of the silicon oxide film, and thus had excellent etch selectivity to the silicon film and the silicon oxide film. Specifically, it could be confirmed that when an inorganic salt was used instead of a metal salt (Comparative Examples 1 to 8), the etch selectivity was significantly lowered, and when the metal salt was included in excess (Example 22), the etch rate was slightly decreased.

(21) In addition, it could be confirmed that when the silicon-based compound was added, the corrosion-resistant performance to the silicon oxide film was improved, and the etch selectivity was also improved, and when the alkanolamine-based compound was added, the surface uniformity was improved. However, when the additive was added in excess (Examples 13 and 26), the etch rate and etch selectivity of silicon were lowered.