Thin film formation method using surface protection material

Abstract

To provide a thin film formation method that can form a very thin film for doping and facilitates adjustment of a composition in a dielectric film to embody a necessary composition ratio, and thereby improves a dielectric constant.SOLUTION: A thin film formation method using a surface protective substance includes the processes of: supplying the surface-protective substance into a chamber in which a substrate is mounted to let the surface adsorb the surface protective substance at proper places on its surface; supplying a precursor for doping into the chamber after cleaning the inside of the chamber, and then supplying a first reactive substance to form a thin film for doping on the surface of the surface; and supplying, after cleaning the inside of the chamber, a second reactive substance after supplying a precursor for dielectric film into the chamber to form a precursor film for dielectric film on the surface of the substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for forming a thin film, and more particularly, to a method for forming a thin film for doping having a very thin thickness, which makes it easy to adjust the thickness of a dielectric film and the composition within the dielectric film, thereby realizing the required composition ratio, thereby improving the dielectric constant. [Background technology]

[0002] 2. Description of the Related Art With the trend toward higher integration and lower power consumption of memory / non-memory semiconductor devices such as DRAM and Flash, the need for the formation of dielectric thin films with excellent properties is becoming more and more pressing.

[0003] For example, zirconium oxide (ZrO2) and hafnium oxide (HfO2), which have a large dielectric constant even at a very thin thickness, are used as capacitor dielectric films. Zirconium oxide (ZrO2) and hafnium oxide (HfO2) have various crystal structures depending on temperature and pressure, and their capacitance varies depending on the structure. Tetragonal structure zirconium oxide (ZrO2) and cubic or tetragonal structure hafnium oxide (HfO2) are known to have approximately twice the capacitance of other structures, but generally, monoclinic structure is more stable at room temperature and pressure.

[0004] As a result, much research has been conducted on obtaining a high dielectric constant by stabilizing the crystal structure of zirconium oxide and hafnium oxide through doping. However, doping causes degradation of dielectric properties and leakage current due to local non-uniformity of composition, and many difficulties have been encountered in its application. Therefore, there is a need to improve the capacitance by improving the uniformity of composition and crystallinity within the thin film, and it is necessary to develop a thin film formation method with improved step coverage. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method for forming a thin film that can form a very thin thin film for doping.

[0006] Another object of the present invention is to provide a method for forming a thin film which is capable of easily controlling the composition in a dielectric film to realize a desired composition ratio, thereby improving the dielectric constant.

[0007] Another object of the present invention is to provide a method for forming a thin film, which can form a thin film having good step coverage while improving crystallinity, thereby providing an excellent semiconductor device.

[0008] Other objects of the present invention will become more apparent from the following detailed description. [Means for solving the problem]

[0009] According to one embodiment of the present invention, a method for forming a thin film using a surface protective material includes a surface protective material supplying step of supplying the surface protective material into the inside of a chamber in which a substrate is placed; a step of purifying the inside of the chamber; a doping precursor supplying step of supplying a doping precursor into the inside of the chamber; a step of purifying the inside of the chamber; a doping thin film forming step of supplying a first reactant into the inside of the chamber to react with the adsorbed doping precursor to form a doping thin film; a dielectric film precursor supplying step of supplying a dielectric film precursor into the inside of the chamber; a step of purifying the inside of the chamber; and a dielectric film forming step of supplying a second reactant into the inside of the chamber to react with the adsorbed dielectric film precursor to form a dielectric film.

[0010] The surface protective material may be represented by the following <Chemical Formula 1>.

[0011] [ka] In the formula 1, n is any one selected from 1 and 2, R is selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0012] The surface protective material may be represented by the following <Chemical Formula 2>.

[0013] [ka] In the above <Chemical Formula 2>, n is independently selected from integers of 1 to 5.

[0014] The surface protective material may be represented by the following <Chemical Formula 3>.

[0015] [ka] In the above <Chemical Formula 3>, n is independently an integer of 0 to 8, R1 is independently selected from an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a hydrogen atom; R2's are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0016] The surface protective material may be represented by the following <Chemical Formula 4>.

[0017] [ka] In the <Chemical Formula 4>, n is independently an integer of 1 to 8, and m is independently an integer of 1 to 5, R1 and R2 are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0018] The surface protective material may be represented by the following <Chemical Formula 5>.

[0019] [ka] In the <Chemical Formula 5>, n is independently an integer of 1 to 5, and m is independently an integer of 0 to 8, R1 is independently selected from an alkyl group having 1 to 8 carbon atoms or a hydrogen atom; R2's are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0020] The surface protective material may be represented by the following <Chemical Formula 6>.

[0021] [ka] In the <Chemical Formula 6>, n is independently an integer of 1 to 8, and m is independently an integer of 1 to 6, R1 and R2 are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0022] The surface protective material may be represented by the following <Chemical Formula 7>.

[0023] [ka] In the <Chemical Formula 7>, n is independently an integer of 0 to 5, and m is independently an integer of 1 to 5, R are each independently selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0024] The surface protective material may be represented by the following <Chemical Formula 8>.

[0025] [ka] In the <Chemical Formula 8>, n is independently an integer of 0 to 8, R1 to R3 are each independently an alkyl group having 1 to 8 carbon atoms, R4 is selected from hydrogen, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms.

[0026] The doping precursor may be represented by the following <Formula 9>.

[0027] [ka]

[0028] In the <Chemical Formula 9>, R1 to R3 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, a dialkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

[0029] The doping precursor may be represented by any one of <Formula 10> to <Formula 14> below.

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] The doping precursor may be represented by the following <Formula 15>.

[0036] [ka] In the <Chemical Formula 15>, A and B are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, and an alkylsilylamine group having 2 to 10 carbon atoms; L is selected from a halogen atom, a hydrogen atom, or an azide group.

[0037] The doping precursor may be represented by any one of <Formula 16> to <Formula 21> below.

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] The doping precursor may be represented by the following <Formula 22>.

[0045] [ka] In the <Chemical Formula 22>, R1 to R6 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

[0046] The doping precursor may be represented by the following <Formula 23>.

[0047] [ka]

[0048] The doping precursor may be represented by the following <Formula 24>.

[0049] [ka] In the <Chemical Formula 24>, R1 to R5 are each independently selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, R6 to R9 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0050] The doping precursor may be represented by any one of <Formula 25> to <Formula 27> below.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] The doping precursor may be represented by the following <Formula 28>.

[0055] [ka] In the <Chemical Formula 28>, R1 to R4 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0056] The doping precursor may be represented by the following <Formula 29>.

[0057] [ka]

[0058] The reactants may be selected from O3, O2, H2O, H2O2, N2O and NH3.

[0059] The dielectric film precursor may be a compound containing at least one of tetravalent metals including Ti, Zr, and Hf. Effect of the Invention

[0060] According to an embodiment of the present invention, the thickness of the doping thin film can be easily controlled by controlling the growth rate of the low doping thin film, thereby obtaining a dielectric film with a desired composition.

[0061] In addition, local compositional non-uniformity is alleviated, thereby obtaining a dielectric film with improved crystallinity and dielectric constant. [Brief description of the drawings]

[0062] [Figure 1] 1 is a flow chart illustrating a thin film forming method according to a first embodiment of the present invention. [Diagram 2] 1 is a graph showing a schematic diagram of a supply cycle according to Comparative Example 1 of the present invention. [Diagram 3] 1 shows the results of XRD (X-ray diffraction) of a thin film according to Comparative Example 1 of the present invention. [Figure 4] 1 is a graph showing secondary ion mass spectrometry (SIMS) of carbon of a thin film according to Comparative Example 1 of the present invention. [Diagram 5] 1 is a graph showing secondary ion mass spectrometry (SIMS) of a thin film of silicon according to Comparative Example 1 of the present invention. [Figure 6] 4 is a graph showing a schematic diagram of a supply cycle according to Example 1 of the present invention. [Figure 7]1 shows the results of XRD (X-ray diffraction) of a thin film according to Example 1 of the present invention. [Figure 8] 1 is a graph showing secondary ion mass spectrometry (SIMS) of a carbon thin film according to Example 1 of the present invention. [Figure 9] 1 is a graph showing secondary ion mass spectrometry (SIMS) of a thin film of silicon according to Example 1 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] The present invention relates to a method for forming a thin film using a surface protective material, and the embodiments of the present invention will be described with reference to the accompanying chemical formulas below. The embodiments of the present invention may be modified in various ways, and the scope of the present invention should not be construed as being limited to the embodiments described below.

[0064] 1 is a flow chart showing a schematic diagram of a thin film formation method according to a first embodiment of the present invention. A substrate is loaded into a process chamber, and the following ALD process conditions are adjusted. The ALD process conditions may include the temperature of the substrate or the process chamber, the chamber pressure, and the gas flow rates, and the temperature is 50-500°C.

[0065] The substrate is exposed to a surface protection material supplied inside the chamber, and the surface protection material is adsorbed onto the surface of the substrate. The surface protection material behaves in the same way as a doping precursor during the process, forming a kind of inhibition layer that prevents the doping precursor from being adsorbed in the subsequent process, mitigating island growth, and improving local compositional non-uniformity in the thin film that is subsequently formed.

[0066] The surface protective material may be represented by the following <Chemical Formula 1>.

[0067] [ka] In the formula 1, n is any one selected from 1 and 2, R is selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0068] The surface protective material may be represented by the following <Chemical Formula 2>.

[0069] [ka] In the above <Chemical Formula 2>, n is independently selected from integers of 1 to 5.

[0070] The surface protective material may be represented by the following <Chemical Formula 3>.

[0071] [ka] In the above <Chemical Formula 3>, n is independently an integer of 0 to 8, R1 is independently selected from an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a hydrogen atom; R2's are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0072] The surface protective material may be represented by the following <Chemical Formula 4>.

[0073] [ka] In the <Chemical Formula 4>, n is independently an integer of 1 to 8, and m is independently an integer of 1 to 5, R1 and R2 are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0074] The surface protective material may be represented by the following <Chemical Formula 5>.

[0075] [ka] In the <Chemical Formula 5>, n is independently an integer of 1 to 5, and m is independently an integer of 0 to 8, R1 is independently selected from an alkyl group having 1 to 8 carbon atoms or a hydrogen atom; R2's are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0076] The surface protective material may be represented by the following <Chemical Formula 6>.

[0077] [ka] In the <Chemical Formula 6>, n is independently an integer of 1 to 8, and m is independently an integer of 1 to 6, R1 and R2 are each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0078] The surface protective material may be represented by the following <Chemical Formula 7>.

[0079] [ka] In the <Chemical Formula 7>, n is independently an integer of 0 to 5, and m is independently an integer of 1 to 5, R are each independently selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0080] The surface protective material may be represented by the following <Chemical Formula 8>.

[0081] [ka] In the <Chemical Formula 8>, n is independently an integer of 0 to 8, R1 to R3 are each independently an alkyl group having 1 to 8 carbon atoms, R4 is selected from hydrogen, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms.

[0082] Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied into the chamber to remove or clean any unadsorbed surface protective material or by-products.

[0083] The substrate is then exposed to a doping precursor supplied inside the chamber, causing the doping precursor to be adsorbed onto the surface of the substrate.

[0084] The doping precursor may be represented by the following <Formula 9>.

[0085] [ka] In the <Chemical Formula 9>, R1 to R3 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, a dialkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

[0086] The doping precursor may be represented by any one of <Formula 10> to <Formula 14> below.

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] The doping precursor may be represented by the following <Formula 15>.

[0093] [ka] In the <Chemical Formula 15>, A and B are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, and an alkylsilylamine group having 2 to 10 carbon atoms; L is selected from a halogen atom, a hydrogen atom, or an azide group.

[0094] The doping precursor may be represented by any one of <Formula 16> to <Formula 21> below.

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] The doping precursor may be represented by the following <Formula 22>.

[0102] [ka]

[0103] In the <Chemical Formula 22>, R1 to R6 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

[0104] The doping precursor may be represented by the following <Formula 23>.

[0105] [ka]

[0106] The doping precursor may be represented by the following <Formula 24>.

[0107] [ka] In the <Chemical Formula 24>, R1 to R5 are each independently selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, R6 to R9 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0108] The doping precursor may be represented by any one of <Formula 25> to <Formula 27> below.

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] The doping precursor may be represented by the following <Formula 28>.

[0113] [ka] In the <Chemical Formula 28>, R1 to R4 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0114] The doping precursor may be represented by the following <Formula 29>.

[0115] [ka]

[0116] For example, when the above-mentioned surface protective material is adsorbed, the doping precursor cannot be adsorbed at the position where the surface protective material is adsorbed, and the surface protective material hinders the adsorption of the doping precursor.

[0117] Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied into the chamber to remove or clean unadsorbed doping precursors or by-products.

[0118] The substrate is then exposed to a reactant supplied inside the chamber to form a doping thin film on the surface of the substrate. The reactant reacts with the doping precursor layer to form the doping thin film, and the reactant may be selected from O3, O2, H2O, H2O2, N2O, and NH3.

[0119] Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied into the chamber to remove or clean unreacted materials or by-products.

[0120] The substrate is then exposed to a dielectric film precursor supplied to the interior of the chamber, and the dielectric film precursor is adsorbed onto the surface of the substrate. The dielectric film precursor may be a compound including at least one of tetravalent metals including Ti, Zr, and Hf.

[0121] Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied into the chamber to remove or clean unadsorbed dielectric film precursors or by-products.

[0122] The substrate is then exposed to a reactant supplied inside the chamber to form a dielectric film on the surface of the substrate. The reactant reacts with the dielectric film precursor layer to form the dielectric film, and the reactant may be selected from O3, O2, H2O, H2O2, N2O, and NH3.

[0123] Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied into the chamber to remove or clean unreacted materials or by-products.

[0124] Comparative Example 1 2 is a graph showing a schematic supply cycle according to Comparative Example 1 of the present invention. Without using the above-mentioned surface protection material, silicon oxide was formed as the doping thin film and hafnium oxide was formed as the dielectric film, diisopropylamino silane (DIPAS) was used as the doping precursor for forming silicon oxide, and tris(dimethylamino)cyclopentadienylhafnium(iv) [CpHf(NMe2)3] (HAC) was used as the dielectric film precursor for forming hafnium oxide, the process temperature was 320°C, and O3 gas was used as the reactant.

[0125] The thin film formation process through the ALD process is as follows, and like the conventional doping method, the cycle ratio of silicon oxide and hafnium oxide is as shown in Table 1. Table 1 shows the cycle ratio of SiO2 and HfO2 and the XRD tetragonal phase ratio (%) according to Comparative Example 1 and Example 1, and the XRD tetragonal phase ratio was calculated as the value of T(101) / [(T101)+ M(-111)+M(111)].

[0126] [Table 1]

[0127] 1) Using Ar as a carrier gas, the doping precursor (DIPAS) is supplied to the reaction chamber at room temperature, and the doping precursor is adsorbed on the substrate. 2) Supply Ar gas into the reaction chamber to remove unadsorbed doping precursors or by-products. 3) O3 gas is supplied to the reaction chamber to form a doping thin film. 4) Ar gas is supplied into the reaction chamber to remove unreacted materials or by-products. 5) Using Ar as a carrier gas, the dielectric film precursor (HAC) is supplied to the reaction chamber at room temperature, and the dielectric film precursor is adsorbed on the substrate. 6) Supply Ar gas into the reaction chamber to remove unadsorbed dielectric film precursors or by-products. 7) O3 gas is supplied to the reaction chamber to form a dielectric film. 8) Ar gas is supplied into the reaction chamber to remove unreacted materials or by-products.

[0128] 3 shows the results of XRD (X-ray diffraction) of the thin film according to Comparative Example 1 of the present invention. When the Si ratio is low (1:30), the HfO and tetragonal ratios are similar, but when the Si ratio increases (1:12), the tetragonal ratio decreases.

[0129] Fig. 4 is a graph showing secondary ion mass spectrometry (SIMS) of a carbon thin film according to Comparative Example 1 of the present invention, and Fig. 5 is a graph showing secondary ion mass spectrometry (SIMS) of a silicon thin film according to Comparative Example 1 of the present invention. In the case of carbon impurity, the level is similar to that of HfO, and in the case of silicon, the peak intensity of Si is at the same level regardless of the cycle ratio of Si.

[0130] Example 1

[0131] 6 is a graph showing a schematic supply cycle according to Example 1 of the present invention. Trimethyl orthoformate was used as a surface protection material to form silicon oxide as a doping thin film and hafnium oxide as a dielectric film, diisopropylamino silane (DIPAS) was used as a doping precursor for forming silicon oxide, and tris(dimethylamino)cyclopentadienylhafnium(iv) [CpHf(NMe2)3] (HAC) was used as a dielectric film precursor for forming hafnium oxide, the process temperature was 320°C, and O3 gas was used as a reactant.

[0132] The thin film formation process through the ALD process is as follows, and as with the conventional doping method, the cycle ratio of silicon oxide and hafnium oxide is as shown in Table 1 above.

[0133] 1) A surface protection material is supplied into the reaction chamber and adsorbed onto the substrate. 2) Supply Ar gas into the reaction chamber to remove unadsorbed surface protective materials or by-products. 3) Using Ar as a carrier gas, the doping precursor (DIPAS) was supplied to the reaction chamber at room temperature, and the doping precursor was adsorbed on the substrate. 4) Supply Ar gas into the reaction chamber to remove unadsorbed doping precursors or by-products. 5) Supply O3 gas into the reaction chamber to form a doping thin film. 6) Ar gas is supplied into the reaction chamber to remove unreacted materials or by-products. 7) Using Ar as a carrier gas, the dielectric film precursor (HAC) is supplied to the reaction chamber at room temperature, and the dielectric film precursor is adsorbed onto the substrate. 8) Supply Ar gas into the reaction chamber to remove unadsorbed dielectric film precursors or by-products. 9) O3 gas is supplied to the reaction chamber to form a dielectric film. 10) Supply Ar gas into the reaction chamber to remove unreacted materials or by-products.

[0134] Figure 7 shows the results of XRD (X-ray diffraction) of the thin film according to Example 1 of the present invention. Regardless of the proportion of Si, the proportion of the tetragonal phase (101) is greater than that of the monoclinic phase, and the deposition rate of the SiO2 adsorbed by the surface protection material is reduced. This is presumably due to the effect of improving the crystallinity of the finely-contained Si concentration. As a result, when implementing the same Si concentration, it is easy to form the tetragonal phase without increasing the THK of the HfO2 matrix (HfO2 Matrix THK).

[0135] FIG. 8 is a graph showing secondary ion mass spectrometry (SIMS) of the carbon thin film according to Example 1 of the present invention, and FIG. 9 is a graph showing secondary ion mass spectrometry (SIMS) of the silicon thin film according to Example 1 of the present invention. The carbon impurity is at the same level as HfO, and the silicon impurity is reduced by more than two times compared to Comparative Example 1, and the peak deviation is also reduced. By using a surface protection material when forming the silicon oxide film, the deposition rate of the silicon oxide film can be reduced, and the Si concentration in the dielectric film to be deposited later can be fine-tuned and the peak deviation can be reduced, making it possible to form a thin film of the desired composition and a uniform layer.

[0136] Although the present invention has been described in detail with reference to the embodiments, other embodiments are possible, and therefore the technical spirit and scope of the following claims should not be limited to the embodiments.

Claims

1. In a thin film formation method using a surface protection material, The thin film forming method includes performing a doping thin film cycle and a dielectric film cycle by an ALD process, The doping thin film cycle includes a surface protective material supply step of supplying the surface protective material into a chamber in which a substrate is placed; cleaning the interior of the chamber; a doping precursor supply step of supplying a doping precursor into the chamber; cleaning the interior of the chamber; and a doping thin film forming process is performed in which a first reactant is supplied into the chamber to react with the adsorbed doping precursor to form a doping thin film; The dielectric film cycle includes a dielectric film precursor supply step of supplying a dielectric film precursor into the chamber; cleaning the interior of the chamber; and a dielectric film forming process is performed in which a second reactant is supplied into the chamber to react with the adsorbed dielectric film precursor to form a dielectric film; Starting with the doping thin film cycle, the doping thin film cycle and the dielectric film cycle are performed in a cycle ratio of 1:12 to 1:30; The doping is a doping to the dielectric film, The method for forming a thin film using a surface protective material, which is trimethyl orthoformate.

2. 2. The method of claim 1, wherein the doping precursor is represented by the following formula: In Formula 9, R1 to R3 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, a dialkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

3. 3. The method of claim 2, wherein the doping precursor is represented by any one of the following Formulas 10 to 14:

4. 2. The method of claim 1, wherein the doping precursor is represented by the following formula: In the formula (15), A and B are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 2 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, and an alkylsilylamine group having 2 to 10 carbon atoms; L is selected from a halogen atom, a hydrogen atom, or an azide group.

5. 5. The method of claim 4, wherein the doping precursor is represented by any one of the following Formulas 16 to 21.

6. 2. The method of claim 1, wherein the doping precursor is represented by the following formula: In Formula 22, R1 to R6 are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkylamine group having 1 to 10 carbon atoms, an arylamine group having 6 to 12 carbon atoms, an aralkylamine group having 7 to 13 carbon atoms, a cyclic amine group having 3 to 10 carbon atoms, a heterocyclic amine group having 3 to 10 carbon atoms, a heteroarylamine group having 6 to 12 carbon atoms, or an alkylsilylamine group having 2 to 10 carbon atoms.

7. 7. The method of claim 6, wherein the doping precursor is represented by the following formula:

8. 2. The method of claim 1, wherein the doping precursor is represented by the following formula: In the formula (24), R1 to R5 are each independently selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms; R6 to R9 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

9. 9. The method of claim 8, wherein the doping precursor is represented by any one of the following Formulas 25 to 27:

10. 2. The method of claim 1, wherein the doping precursor is represented by the following formula: In Formula 28, R1 to R4 are each independently selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkylamine group having 1 to 4 carbon atoms, a dialkylamine group having 2 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

11. 11. The method of claim 10, wherein the doping precursor is represented by the following formula:

12. The reactants are O 3 , O 2 , H 2 O.H. 2 O 2 , N 2 O and NH 3 A method for forming a thin film using the surface protective material according to claim 1, which is selected from the following:

13. 2. The method of claim 1, wherein the dielectric film precursor is a compound containing at least one of tetravalent metals including Ti, Zr, and Hf.

Images