Thin film forming method

Abstract

A thin film forming method according to an aspect of the present application utilizes a substrate processing apparatus including a process chamber providing a reaction space inside, a substrate support portion provided in the process chamber to place a substrate on an upper portion, and a gas injection portion to supply a process gas to the substrate support portion in the reaction space. The thin film forming method includes the steps of placing a substrate on the substrate support portion in the process chamber, and repeatedly forming a TiSiN thin film on the substrate by inhibitor atomic layer deposition (ALD) for a plurality of times by using a TiSiN unit cycle. The TiSiN unit cycle includes the steps of repeatedly at least once a TiN unit cycle to form a TiN layer on the substrate by inhibitor atomic layer deposition, and repeatedly at least once a SiN unit cycle to form a SiN layer on the TiN layer by atomic layer deposition.

Description

TECHNICAL FIELD

[0001] The present invention relates to semiconductor manufacturing, and more particularly, to a thin film forming method using an atomic layer deposition method. BACKGROUND

[0002] As the high integration of semiconductor devices, the demand for a very thin thin film is increasing as the aspect ratio increases, and a thin film forming method with excellent step coverage is required. As a deposition method capable of overcoming such various problems, an atomic layer deposition process (ALD) is being applied. In particular, if the atomic layer deposition process (ALD) is applied, the thickness of the thin film can be controlled in atomic layer or molecular layer units.

[0003] Further, in the semiconductor device field, device line width miniaturization, power consumption reduction for operating devices, and improvement of thin film quality are required, which are related to improvement of device operation reliability and operation speed. For example, in the field of dynamic random access memory (DRAM), improvement of the capacitance value of a capacitor is being required, and thus a barrier thin film for a capacitor electrode is also required to have higher barrier properties, higher step coverage, higher film hardness represented by hardness and modulus, and higher film quality, etc. SUMMARY

[0004] (PROBLEMS TO BE SOLVED)

[0005] The present invention is to solve various problems including the above-described problems, and aims to provide a thin film forming method capable of obtaining a high-quality barrier thin film having high step coverage, high barrier properties, etc. However, such a problem is exemplary, and the scope of the present invention is not limited thereby.

[0006] (MEANS FOR SOLVING THE PROBLEMS)

[0007] A thin film forming method according to one aspect of the present invention for solving the above-described problem, using a substrate processing apparatus including a process chamber providing a reaction space inside, a substrate support portion provided in the process chamber to place a substrate on an upper portion, and a gas injection portion supplying a process gas to the substrate support portion in the reaction space. The thin film forming method includes the steps of placing a substrate on the substrate support portion in the process chamber, repeating an ALD-TiSiN unit cycle using an inhibitor on the substrate a plurality of times to form an ALD-TiSiN thin film by atomic layer deposition, wherein the ALD-TiSiN unit cycle using the inhibitor includes the steps of repeating an ALD-TiN unit cycle using an inhibitor at least once to form an ALD-TiN layer on the substrate, and repeating an ALD-SiN unit cycle at least once to inject a Si element on the ALD-TiN layer.

[0008] In the thin film forming method, the ALD-TiN unit cycle using the inhibitor can include: a step of supplying the inhibitor and the source on the substrate at least once, including the inhibitor supply step and the titanium-containing gas supply step in order or in reverse order; and a step of supplying the nitrogen-containing reaction gas on the substrate at least once.

[0009] In the thin film forming method, a purge gas supply step can be additionally included after the inhibitor supply step, after the titanium-containing gas supply step, and after the reaction gas supply step.

[0010] In the thin film forming method, each step can be performed in a state of continuously supplying a purge gas.

[0011] In the thin film forming method, a pulse purge gas supply step can be additionally included after the inhibitor supply step, after the titanium-containing gas supply step, and after the reaction gas supply step.

[0012] In the thin film forming method, the opening rate of a throttle valve of the process chamber is increased after the inhibitor supply step, after the titanium-containing gas supply step, and after the reaction gas supply step, the state of increasing the opening rate of the throttle valve is maintained in the pulse purge gas supply step, and the opening rate of the throttle valve is decreased again after the pulse purge gas is supplied.

[0013] In the thin film forming method, the ALD-SiN unit cycle includes steps of: supplying the silicon-containing gas on the substrate at least once; and supplying the nitrogen-containing reaction gas on the substrate at least once. Wherein, each step can be performed in a state of continuously supplying a purge gas.

[0014] In the thin film forming method, a pulse purge gas supply step can be additionally included after the silicon-containing gas supply step and after the reaction gas supply step.

[0015] In the thin film forming method, the opening rate of a throttle valve of the process chamber is increased after the silicon-containing gas supply step and after the reaction gas supply step, the state of increasing the opening rate of the throttle valve is maintained in the pulse purge gas supply step, and the opening rate of the throttle valve can be decreased again after the pulse purge gas is supplied.

[0016] In the thin film forming method, before the step of repeating the ALD-TiSiN unit cycle using the inhibitor multiple times, a step of forming an ALD-TiN thin film on the substrate using atomic layer deposition or using atomic layer deposition using an inhibitor can be included.

[0017] In the thin film forming method, the thickness of the ALD-TiN thin film can be in the range of 3 to 30.

[0018] In the thin film forming method, the inhibitor gas contains steam of an organic solvent containing carbon and chlorine, the titanium-containing gas contains TiCl4 steam, and the reaction gas can contain NH3 gas.

[0019] In the thin film forming method, the silicon-containing gas contains at least one selected from SiH4 gas and DCS gas, and the reaction gas can contain NH3 gas.

[0020] In the thin film forming method, the inhibitor can contain steam of an organic solvent containing carbon and chlorine.

[0021] In the thin film forming method, the ALD-TiSiN thin film using the inhibitor can be used as a lower electrode or an upper electrode diffusion preventing film in a capacitor of a DRAM device.

[0022] (EFFECTS OF THE INVENTION)

[0023] According to the thin film forming method of the embodiment of the present application configured as described above, a high-quality barrier thin film having high step coverage, high thin film strength (hardness, modulus), high barrier properties, and the like can be obtained. Of course, the scope of the present application is not limited by such effects. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A schematic cross-sectional view showing a substrate processing apparatus used in the thin film forming method of an embodiment of the present application is shown.

[0025] Figure 2 A flowchart showing the thin film forming method of an embodiment of the present application is shown.

[0026] Figure 3a and Figure 3c A process pattern diagram showing the ALD-TiN unit cycle repetition step of the inhibitor in the thin film forming method of an embodiment of the present application is shown. Figure 3b A process pattern diagram showing the enhanced ALD-SiN unit cycle repetition step is shown.

[0027] Figure 4a and Figure 4b Process pattern diagrams showing the ALD-TiN unit cycle repetition step of the inhibitor and the enhanced ALD-SiN unit cycle repetition step of another embodiment, respectively, in the thin film forming method of an embodiment of the present application are shown.

[0028] Figure 5a and Figure 5bis a process pattern diagram showing the inhibitor ALD-TiN unit cycle repetition step and the enhancement ALD-SiN unit cycle repetition step in the thin film forming method according to an embodiment of the present application.

[0029] Figure 6 is a flow chart showing a thin film forming method according to another embodiment of the present application.

[0030] Figure 7 is a flow chart showing a thin film forming method according to another embodiment of the present application.

[0031] Figure 8 is a process pattern diagram showing the inhibitor ALD-TiN unit cycle in the thin film forming method according to an embodiment of the present application.

[0032] Figure 9a and Figure 9b is a table showing the process characteristics of the inhibitor ALD-TiN thin film in the thin film forming method according to an embodiment of the present application.

[0033] Figures 10a to 10d is a graph showing the thin film quality and step coverage characteristics of the ALD-TiN thin film according to the inhibitor flow rate.

[0034] Figure 11 is a probability cross-sectional view showing a DRAM capacitor structure including a thin film manufactured according to an embodiment of the present application.

[0035] (Explanation of Reference Numerals)

[0036] 100: substrate processing apparatus

[0037] 110: process chamber

[0038] 120: gas injection section

[0039] 130: substrate support section

[0040] 140: gas supply device

[0041] 154: vacuum pump DETAILED DESCRIPTION

[0042] Hereinafter, preferred various embodiments of the present application will be explained in detail with reference to the accompanying drawings.

[0043] Embodiments of the present application are provided to more fully inform those skilled in the art of the present application, the following embodiments can be modified in various different forms, the scope of the present application is not limited to the following embodiments. On the contrary, these embodiments make the disclosure of the present application more thorough and complete, and are provided to convey the idea of the present application to those skilled in the art. In addition, in order to facilitate and clear illustration, the thickness or size of each layer is exaggerated in the drawings.

[0044] Figure 1 A schematic cross-sectional view of a substrate processing apparatus 100 utilized in a thin film forming method according to an embodiment of the present application is shown.

[0045] Referring to Figure 1 The substrate processing apparatus 100 can include a process chamber 110, a gas injection portion 120, a substrate support portion 130, and a gas supply device 140.

[0046] The process chamber 110 can provide a reaction space 112 inside. For example, the reaction space 112 of the process chamber 110 can be connected to a trap device 152 and a pumping device 154 through an exhaust port to provide a vacuum environment. The exhaust port is connected to the pumping device 154, such as a vacuum pump, through a pipe, whereby various process gases inside the reaction space 112 of the process chamber 110 can be exhausted or a vacuum environment can be created inside the reaction space 112.

[0047] The trap device 152 functions to filter the powder formed by the exhaust gas to protect the pumping device 154. Further, a throttle valve 151 can be provided at the exhaust port. The throttle valve 151 adjusts the opening rate of the pumping line between the process chamber 110 and the vacuum pump 154, which can be used to adjust the pressure in the process chamber 110.

[0048] Various shapes can be provided for the process chamber 110, for example, it can include a chamber body defining the reaction space 112 and a cover portion or top cover at the upper end of the chamber body. Further, a sealing member, such as an O-ring, can be interposed between the chamber body and the top cover to achieve a vacuum seal. A gate (not shown) can be formed on the side of the chamber body, which is a passage through which the substrate S can be loaded or unloaded in the processing space.

[0049] The substrate support portion 130 can be provided in the process chamber 110 to place the substrate S at the upper portion. For example, the substrate support portion 130 can be moved up and down by a shaft, thereby being able to move between a loading position where the substrate S can be introduced and a process position where the process is performed. Further, a plurality of substrate support pins (not shown) can be provided in the substrate support portion 130 to be able to support the substrate when the substrate S is loaded and unloaded.

[0050] The upper plate shape of the substrate support portion 130 substantially corresponds to the shape of the substrate S, or is not limited thereto, but can provide various shapes greater than the substrate S capable of stably placing the substrate S. In an example, a shaft of the substrate support portion 130 can be connected to an external motor (not shown) so that the shaft can be raised and lowered, in which case, in order to maintain airtightness, a bellows (not shown) can also be connected. Further, since the substrate support portion 130 is configured to place the substrate S on the upper portion, it can also be referred to as a substrate placing portion, a susceptor, etc.

[0051] In some embodiments, the substrate support portion 130 can further include an electrostatic electrode that applies an electrostatic force to the substrate S to fix the substrate S on the upper portion of the substrate support portion 130. The electrostatic electrode can receive DC power from a power supply portion. Further, the substrate support portion 130 can include a heater (not shown) inside to heat the substrate S. The heater can receive RF power supply through a heater power supply portion.

[0052] The gas injection portion 120 is provided in the process chamber 110 and faces the substrate support portion 130 to supply a process gas to the substrate support portion 130 in the reaction space 112 of the process chamber 110. For example, the gas injection portion 120 can be coupled to a top cover of the process chamber 110. An intake hole is formed at the upper end of the gas injection portion 120, and a plurality of exhaust holes can be formed at the lower end to uniformly supply the process gas to the substrate S. For example, the gas injection portion 120 can also be referred to as a showerhead.

[0053] The gas supply device 140 can supply a process gas to the gas injection portion 120. For example, the gas supply device 140 can be connected to the gas injection portion 120 through a top cover. The gas supply device 140 can include a piping line 142 for supplying a source gas, a supply inhibitor, a reaction gas, and a purge gas. Further, the piping line 142 can be connected to the gas injection portion 120 through a valve block 146. The valve block 146 can include a valve for opening and closing the piping line 142.

[0054] In some embodiments, the substrate processing device 100 can be used as an atomic layer deposition device, and more specifically, can be used for deposition of a TiN thin film, a TiSiN thin film, etc. For example, the gas supply device 140 vaporizes a liquid metal precursor and supplies a titanium-containing gas as a first source gas to the gas injection portion 120 through the piping line 142, or vaporizes an inhibitor and can supply it to the gas injection portion 120 through the piping line 142. Further, the gas supply device 140 supplies a silicon-containing gas as a second source gas to the gas injection portion 120 through the piping line 142, or can supply a purge gas to the gas injection portion 120 through the piping line 142.

[0055] In some embodiments, to form an ALD-TiN layer by atomic layer deposition, the source gas includes a titanium-containing gas. For example, the titanium-containing gas can include TiCl4vapor or TDMAT (tetra(dimethylamino) titanium) gas. As described above, the titanium-containing gas can be vaporized from a titanium precursor. Further, the reactant gas includes a nitrogen-containing gas. For example, the nitrogen-containing gas can include NH3gas.

[0056] In some embodiments, to form an ALD-TiN layer by atomic layer deposition, the source gas includes a titanium-containing gas. For example, the titanium-containing gas can include TiCl4vapor or TDMAT (tetra(dimethylamino) titanium) gas. As described above, the titanium-containing gas can be vaporized from a titanium precursor. Further, the reactant gas includes a nitrogen-containing gas. For example, the nitrogen-containing gas can include NH3gas.

[0057] In some embodiments, to form an ALD-SiN layer by atomic layer deposition, the source gas includes a silicon-containing gas. For example, the silicon-containing gas can include SiH4gas or DCS (dichlorosilane) gas. Further, the reactant gas includes a nitrogen-containing gas. For example, the nitrogen-containing gas can include NH3gas.

[0058] In embodiments of the present application, atomic layer deposition with an inhibitor can be different from general atomic layer deposition in that an inhibitor is added. General atomic layer deposition can be different from atomic layer deposition with an inhibitor in that an inhibitor is not added. In embodiments of the present application, atomic layer deposition with an inhibitor is referred to as inhibitor atomic layer deposition, and general atomic layer deposition without an inhibitor is also referred to as general atomic layer deposition.

[0059] Hereinafter, a substrate processing method according to embodiments of the present application is described using the substrate processing apparatus 100. For example, the substrate processing method can include a method of forming a TiSiN thin film on the substrate S and / or a method of forming a TiN thin film on an upper portion or a lower portion of such a TiSiN thin film.

[0060] Figure 2 is a flowchart showing a thin film forming method according to an embodiment of the present application.

[0061] Referring to Figure 1 and Figure 2 A substrate loading step S10 can be performed to place the substrate S on the substrate support portion 130 in the process chamber 110.

[0062] In some embodiments, a substrate preheating step S11 can be performed to heat the substrate S on the substrate support portion 130. For example, a heater in the substrate support portion 130 can heat the substrate S to a predetermined temperature.

[0063] Then, a step of repeating the ALD-TiSiN unit cycle with inhibitor S13 multiple times is performed to form an ALD-TiSiN film on the substrate S by atomic layer deposition (ALD). For example, in the ALD-TiSiN unit cycle S13, a predetermined thickness of the ALD-TiSiN film can be formed on the substrate S by the self-saturation reaction of the unit cycle, such as an atomic layer unit to a molecular layer unit of the ALD-TiSiN film.

[0064] For example, the ALD-TiSiN unit cycle with inhibitor S13 can include a step of repeating the ALD-TiN unit cycle with inhibitor at least once (S14) to form an ALD-TiN layer on the substrate S, and a step of repeating the ALD-SiN unit cycle at least once (S15) to inject Si elements on the ALD-TiN layer. In some embodiments, the ALD-TiN unit cycle can be repeated L times (L is a natural number), and the ALD-SiN unit cycle can be repeated M times (M is a natural number). Such an ALD-TiSiN unit cycle S13 can be different from the prior art in that it utilizes inhibitor atomic layer deposition in forming the ALD-TiN layer.

[0065] More specifically, during the repeating of the ALD-TiN unit cycle L times (S14), a predetermined thickness of the ALD-TiN layer can be formed on the substrate S by the repeating of the self-saturation reaction, such as at least an atomic layer unit of the ALD-TiN layer. Further, the Si elements are injected on the substrate S as needed during the ALD-SiN unit cycle. The value of L can be selected as the number of times for uniform formation of the atomic layer unit of the ALD-TiN layer on the substrate S. The value of M can be selected as the number of times for generating the Si concentration as needed in the inhibitor ALD TiSiN (step S13) film.

[0066] On the other hand, in view of the physical properties of the ALD-TiSiN film, such as resistivity and strength (hardness) characteristics, it is necessary to adjust the Si content in the ALD-TiSiN film. For example, the Si content in the ALD-TiSiN film is preferably in the range of 3 to 30%. The more the Si content in the ALD-TiSiN film is increased or decreased, the more the film strength is increased, and then the film strength is sharply decreased below any critical point. Therefore, it is preferable that the Si content be limited in the optimum range in view of the strength of the ALD-TiSiN film. If the L value is significantly increased compared to the M value, because the Si concentration is decreased, the resistivity characteristics approach those of the ALD-TiN film, and the film strength is increasingly greater, but the Si concentration below a certain critical point excessively weakens the film strength, or there is not enough Si source to penetrate to the inside of the hole in the pattern, and thus the device characteristics can be deteriorated. At this point, the L:M ratio can be appropriately selected, and the resistivity characteristics and the strength can be selected in the range of 3: 1 to 8: 1.

[0067] Then, the step of judging whether the inhibitor ALD-TiSiN unit cycle S13 is repeated N times (N is a natural number) can be performed next (S16). If the number of times of the inhibitor ALD-TiSiN unit cycle S13 is not N times, the inhibitor ALD-TiSiN unit cycle S13 is repeated; if the number of times of the inhibitor ALD-TiSiN unit cycle S13 is N times, the next step can be performed next. Thus, the inhibitor ALD-TiSiN unit cycle S13 can be repeated N times. The value of N can be determined according to the target thickness value of the inhibitor ALD-TiSiN film.

[0068] Then, the optional post purge step S18 can be performed next. In this post purge step S18, the residual gas and byproducts in the process chamber 110 can be pumped out by the vacuum pump 154 together with a purge gas. For example, the purge gas can include an inert gas, such as N2 gas or Ar gas.

[0069] Then, if the process is completed, the substrate unloading step S19 can be performed. For example, the process can be completed by transferring the substrate S from the substrate support portion 130 to the outside of the process chamber 110.

[0070] Hereinafter, the inhibitor ALD-TiN unit cycle repeating step S14 and the enhancement ALD-SiN unit cycle repeating step S15 will be described in more detail.

[0071] Figure 3a and Figure 3b are process pattern diagrams respectively showing the inhibitor ALD-TiN unit cycle repeating step S14 and the enhancement ALD-SiN unit cycle repeating step S15 of an embodiment of the film forming method of the present application.

[0072] Referring to Figure 1 , Figure 3a and Figure 3c , the inhibitor ALD-TiN unit cycle can include: at least one inhibitor and source supply step S14-1, including a step of supplying an inhibitor on the substrate S and a step of supplying a titanium-containing gas, such as TiCl4gas, in order or in reverse order; a step S14-2 of supplying a nitrogen-containing reaction gas, such as NH3gas, on the substrate S at least once. For example, the inhibitor and source supply step S14-1 can include inhibitor-source supply as shown in Figure 3a or source-inhibitor supply as shown in Figure 3c . The number of times or the number of repetitions of the inhibitor and source supply step S14-1 can be appropriately selected to uniformly adsorb the inhibitor and the titanium-containing gas on the substrate S. Similarly, the number of times of the reaction gas supply step S14-2 can be appropriately selected to supply sufficient reaction gas on the substrate S to form a TiN layer. Further, a purge gas supply step S14-3 can be performed to continuously supply a purge gas during the execution of the above steps (S14-1, S14-2). Thus, the above steps (S14-1, S14-2) can be performed in a state where the purge gas is continuously supplied, respectively. In a variation of this embodiment, the purge gas supply step S14-3 can be additionally provided after each of the above steps. For example, the purge gas supply step S14-3 can be additionally provided in a pulse manner after the inhibitor supply step, after the titanium-containing gas supply step, and after the reaction gas supply step, respectively.

[0073] Hereinafter, the ALD-TiN unit cycle reaction using an inhibitor will be described in more detail.

[0074] As shown in Figure 8 , if an inhibitor I is supplied on the substrate S and a purge gas is supplied, the inhibitor I can be adsorbed on a part of the substrate S. Then, if a titanium-containing gas, such as TiCl4gas, is supplied on the substrate S, the TiCl4gas can be adsorbed on the substrate S. However, because the inhibitor I is adsorbed, the amount of adsorption of the TiCl4gas is reduced. Thus, the inhibitor I can function to hinder the adsorption of the TiCl4gas. In contrast, the TiCl4gas can be first supplied, and then the inhibitor I can be supplied. The supply order can be determined in consideration of the aspect ratio and structure of the pattern.

[0075] Then, if a reaction gas, such as NH3gas, is supplied on the substrate S, the adsorbed TiCl4gas can react with the NH3gas to form an ALD-TiN layer.

[0076] This inhibitor-based atomic layer deposition (ALD-TiN) method results in a slower deposition rate than conventional ALD-TiN deposition without inhibitors. Conversely, ALD-TiN films formed using inhibitor-based ALD-TiN deposition exhibit superior step coverage, film purity, and resistivity compared to those formed using conventional ALD-TiN deposition.

[0077] The inhibitor ALD-TiN unit cyclic step S14 is to perform the above-mentioned inhibitor and source supply step S14-1 at least once, and the reaction gas supply step S14-2 at least once, and then these steps can be performed multiple times, for example L times.

[0078] Reference Figure 1 and Figure 3b Enhancing the ALD-SiN unit cycle may include: a step of supplying a silicon-containing gas, such as SiH4 gas, to the substrate S at least once (S15-1); and a step of supplying a nitrogen-containing reactive gas, such as NH3 gas, to the substrate S at least once (S15-2). The number of times the silicon-containing gas supply step S15-1 is performed can be selected by the number of times a desired concentration of silicon-containing gas is injected onto the substrate S. In some embodiments, when forming a thin film within a high aspect ratio via pattern, the number of times the silicon-containing gas supply step S15-1 is performed can be increased to ensure a sufficient supply of process gas. The number of times the reactive gas supply step S15-2 is performed can be selected by the number of times sufficient reactive gas is supplied to the substrate S to uniformly adhere and bond Si onto the substrate.

[0079] The enhanced ALD-SiN unit cycle repetition step S15 can be performed by alternating and repeating the silicon-containing gas supply step S15-1 and the reaction gas supply step S15-2 multiple times, for example, M times.

[0080] The purging gas supply step S15-3 can actually be combined with the above. Figure 3a The purging gas supply step S14-3 is the same.

[0081] Figure 4a and Figure 4b In the thin film formation method of an embodiment of the present invention, process diagrams of the inhibitor ALD-TiN unit cycling step S14a and the enhanced ALD-SiN unit cycling step S15a are shown respectively, according to another embodiment. The inhibitor ALD-TiN unit cycling step S14a includes an inhibitor and source supply step S14a-1 and a reactive gas supply step S14a-2. In this embodiment, steps (S14a, S15a) are... Figure 3a and Figure 3b The steps (S14, S15) are additional structural elements that can be referenced from each other, so repeated explanations are omitted.

[0082] Referring to Figure 1 and Figure 4a In the inhibitor source supply step S14a-1, a pulsed purge gas, such as a pulsed N2 gas supply step, can be additionally provided after the inhibitor supply step and after the Ti-containing gas supply step. In addition, in the reaction gas supply step S14a-2, a pulsed purge gas, such as a pulsed N2 gas supply step, can be additionally provided after the reaction gas supply step. For the purge gas supply step S14a-3, reference can be made to the purge gas supply step S14-3 of Figure 3a .

[0083] Referring to Figure 1 and Figure 4b In the Si-containing gas supply step S15a-1, a pulsed purge gas, such as a pulsed N2 gas supply step, can be additionally provided after each of the steps of supplying the Si-containing gas. In addition, in the reaction gas supply step S15a-2, a pulsed purge gas, such as a pulsed N2 gas supply step, can be additionally provided after the reaction gas supply step. For the purge gas supply step S15a-3, reference can be made to the purge gas supply step S15-3 of Figure 3b .

[0084] In the inhibitor ALD-TiN unit cycle repeat step S14a and the enhanced ALD-SiN unit cycle repeat step S15a described above, the supply of the pulsed purge gas can play a role in improving the step coverage and improving the thickness uniformity when forming the inhibitor ALD-TiN layer and the inhibitor ALD-TiSiN layer in a high aspect ratio hole pattern. More specifically, the supply of the pulsed purge gas can play a role in continuously reducing the flow rate of the purge gas, further improving the partial pressure of the process gas, and improving the purge efficiency of the residual gas, inhibiting the accumulation of the process gas at the entrance of the hole pattern, and further improving the step coverage in the high aspect ratio hole pattern.

[0085] Figure 5a and Figure 5b are process pattern diagrams respectively showing an inhibitor ALD-TiN unit cycle repeat step S14b and an enhanced ALD-SiN unit cycle repeat step S15b of another embodiment in the thin film forming method of the embodiment of the present application. In this embodiment, the steps (S14b, S15b) are provided in Figure 4a and Figure 4b The steps (S14a, S14b) of

[0086] Referring to Figure 1 and Figure 5aIn the inhibitor and source supplying step S14b-1, a pulsed purge gas, such as a pulsed N2gas supplying step, can be additionally provided after each of the inhibitor supplying steps and after each of the titanium-containing gas supplying steps. Also, in the reaction gas supplying step S14b-2, a pulsed purge gas, such as a pulsed N2gas supplying step, can be additionally provided after the reaction gas supplying step.

[0087] Further, a step of adjusting the opening rate of the throttle valve 151 of the process chamber 110 (S14b-4) can be additionally provided in the step of supplying the pulsed purge gas. The purge gas supplying step S14b-3 can be referred to the purge gas supplying step S14-3 of Figure 3a

[0088] In some embodiments, the above-mentioned step of adjusting the opening rate of the throttle valve 151 of the process chamber 110 (S14b-4, S15b-4) can be performed to change the opening rate of the throttle valve 151 from a to b, where b is greater than a, and then can be changed back to a. More specifically, the opening rate adjusting step (S14b-4, S15b-4) increases the opening rate of the throttle valve 151 after each of the inhibitor supplying steps and after each of the titanium-containing gas supplying steps and after the reaction gas supplying step S14b-2, maintains the increased opening rate of the throttle valve 151 in the pulsed purge gas supplying step, and then can decrease the opening rate of the throttle valve 151 after supplying the pulsed purge gas.

[0089] As described above, increasing the opening rate of the throttle valve 151 while supplying the pulsed purge gas can maximize the purge effect, increase the flow of the process gas into the ultrafine pattern and the hole pattern, and thus can effectively improve the step coverage. However, the step of adjusting the opening rate of the throttle valve 151 (S14b-4, S15b-4) is disadvantageous in terms of productivity, and thus it is necessary to determine whether to apply it in consideration of this.

[0090] Referring to Figure 1 and Figure 5b In the silicon-containing gas supplying step S15b-1, a pulsed inert gas, such as a pulsed N2gas supplying step, can be additionally provided after each of the silicon-containing gas supplying steps. Also, in the reaction gas supplying step S15b-2, a pulsed inert gas, such as a pulsed N2gas supplying step, can be additionally provided after the reaction gas supplying step.

[0091] Further, a step of adjusting the opening rate of the throttle valve 151 of the process chamber 110 (S15b-4) can be additionally provided in the pulsed inert gas supplying step. For the purge gas supplying step S15b-3, reference can be made to the purge gas supplying step S14-3 of Figure 3b ​The purge gas supply step S15-3 is performed after the opening ratio adjustment step S15b-4. For example, the opening ratio adjustment step S15b-4 is a step of increasing the opening ratio of the throttle valve 151 after the silicon-containing gas supply step S15b-1 and after the reaction gas supply step S15b-2, maintaining the state of increasing the opening ratio of the throttle valve 151 in the step of supplying the pulse-shaped purge gas, and decreasing the opening ratio of the throttle valve 151 again after the supply of the pulse-shaped purge gas.

[0092] Figure 6 is a flowchart showing a thin film formation method according to another embodiment of the present application. The thin film formation method according to this embodiment is a method of forming a thin film on a substrate S by repeating a unit cycle S13 of forming an ALD-TiSiN film on the substrate S and a unit cycle S14 of forming an ALD-TiN film on the substrate S. Figure 2 The thin film formation method according to this embodiment is a method of forming a thin film on a substrate S by repeating a unit cycle S13 of forming an ALD-TiSiN film on the substrate S and a unit cycle S14 of forming an ALD-TiN film on the substrate S.

[0093] Referring to Figure 1 and Figure 6 , the inhibitor ALD-TiSiN unit cycle S13 can be repeated a plurality of times, and then a step of forming an ALD-TiN film on the substrate S by atomic layer deposition (S17a) or a step of forming an inhibitor ALD-TiN film by using an inhibitor (S17b) can be added. For example, the inhibitor ALD-TiN film formation step (S17a or S17b) can be performed after the inhibitor ALD-TiSiN unit cycle S13 is repeated N times.

[0094] The step of forming an ALD-TiN film by using an inhibitor S17b can refer to the ALD-TiN unit cycle repeating step (S14, S14a, S14b) of Figure 3a , Figure 4a and Figure 5a . However, the number of repetitions of the ALD-TiN unit cycle can be different from each other depending on the target thickness of the ALD-TiN film. For example, the step of forming an ALD-TiN film by using an inhibitor S17b can repeat the above-described ALD-TiN unit cycle P times (P is a natural number).

[0095] On the other hand, the step of forming an ALD-TiN film by atomic layer deposition S17a can be understood as a step of excluding the supply of an inhibitor from the above-described ALD-TiN unit cycle repeating step (S14, S14a, S14b) of Figure 3a , Figure 4a and Figure 5a . For example, the ALD-TiN film formation step S17a can repeat a normal ALD-TiN unit cycle without an inhibitor Q times (Q is a natural number).

[0096] Then, a post purge step (S18a or S18b) can be performed after the ALD-TiN film formation step (S17a or S17b). Then, a substrate unloading step S19 can be performed.

[0097] In this embodiment, an inhibitor ALD-TiSiN film is formed on the substrate S, and then an inhibitor ALD-TiN or ALD TiN film can be formed on the inhibitor ALD-TiSiN film. For example, in the case where the inhibitor ALD-TiSiN film is used as a diffusion barrier film, the inhibitor ALD-TiN or ALD TiN film can be used as an upper electrode layer. For example, the thickness of the ALD-TiN film can be in the range of 3 to 300.

[0098] Figure 7 is a flowchart showing a film forming method of another embodiment of the present application. The film forming method of this embodiment is a modification of the film forming method of Figure 6 in which a part of the structure is modified, so that they can be referred to each other, and thus the repeated explanation is omitted in the embodiment.

[0099] Referring to Figure 7 , before the step of repeating the ALD-TiSiN unit cycle S13, a step of forming an ALD-TiN film on the substrate S by atomic layer deposition (S12a) or a step of forming an inhibitor ALD-TiN film (S12b) can be added. These steps (S12a, S12b) can be referred to the steps (S17a, S17b) of Figure 6 , respectively.

[0100] Then, after the ALD-TiN film forming step (S12a or S12b), a post purge step (S20a, S20b) can be performed, respectively. Then, the step of repeating the ALD-TiSiN unit cycle S13 can be performed.

[0101] In this embodiment, an inhibitor ALD-TiN or ALD-TiN film is formed on the substrate S, and then an inhibitor ALD-TiSiN film can be formed on the inhibitor ALD-TiN or ALD-TiN film. For example, in the case where the inhibitor ALD-TiSiN film is used as a diffusion barrier film, the inhibitor ALD-TiN or ALD-TiN film can be used as a lower electrode layer. For example, the thickness of the ALD-TiN film can be in the range of 3 to 300.

[0102] Hereinafter, the physical properties of the ALD-TiN layer using the conventional atomic layer deposition and the ALD-TiN layer using the inhibitor atomic layer deposition are compared and explained.

[0103] Figure 9a and Figure 9b is a schematic diagram showing the characteristics of the inhibitor ALD-TiN layer in the film forming method of the embodiment of the present application; Figures 10a to 10dis a graph showing characteristics of ALD-TiN layers according to inhibitor flow rates.

[0104] Referring to Figure 9a , Figure 9b and Figures 10a to 10d , it can be seen that, compared to ALD-TiN using a general atomic layer deposition (general ALD-TiN), in the case of ALD-TiN using an inhibitor atomic layer deposition (inhibitor ALD-TiN), although the deposition rate is reduced, the bulk resistivity is reduced and the step coverage is greater. Thus, it can be seen that, if ALD-TiN using an inhibitor atomic layer deposition (inhibitor ALD-TiN) is applied, the resistivity is reduced, the electrical characteristics are improved, the step coverage is increased, and further, the coating characteristics can be improved. This tendency is similar at a temperature of 460°C or 550°C of the platform heater of the substrate support portion 130.

[0105] In the case of a high aspect ratio hole pattern structure, the hole entrance becomes narrower, it is difficult to inject a process gas into the hole, and thus the flow rate of the process gas is increased. However, if the flow rate of the process gas is increased, the deposition rate is fast, and thus the hole entrance is quickly clogged, and it is difficult to deposit inside the hole. Thus, in this case, it is effective to quantitatively distribute the process gas and to spray in multiple times, and further, it is effective to use an inhibitor to reduce the process rate while adjusting the physical properties of the ALD-TiN film.

[0106] In addition, the deposition rate of the ALD-TiN film is slowed down using an inhibitor, the number of repetitions of the ALD-TiN unit cycle is increased, and further, the number of times of supplying a reaction gas, such as NH3, is increased, and thus the reactivity of a source gas, such as TiCl4, is improved, and the physical properties, such as the resistivity and the strength, of the ALD-TiN film can be improved. However, the more the flow rate of the inhibitor is increased, the more the improvement of such electrical characteristics and step coverage is facilitated, but the productivity is deteriorated. Thus, considering the improvement of the quality of the inhibitor ALD-TiN film and the productivity, it is necessary to select the flow rate of the inhibitor.

[0107] Figure 11 is a probabilistic cross-sectional view showing a DRAM capacitor structure including a film manufactured according to an embodiment of the present application.

[0108] Referring to Figure 11 , a dynamic random access memory (DRAM) capacitor can include a lower electrode stack 31, a dielectric layer 35, and an upper electrode stack 36. For example, the lower electrode stack 31 includes a lower electrode layer 32 and a lower barrier layer 34, and the upper electrode stack 36 can include an upper barrier layer 37 and an upper electrode layer 39.

[0109] More specifically, the lower electrode stack 31 can be formed of a material having a lower work function than the upper electrode stack 36, and the upper electrode stack 36 can be formed of a material having a higher work function than the lower electrode stack 31. Figure 6ALD-TiN film or ALD-TiN film and the inhibitor ALD-TiSiN film structure of the upper portion, the upper electrode stack 36 can correspond to Figure 7 ALD-TiSiN film and the inhibitor ALD-TiN or ALD-TiN film structure of the upper portion. That is, the lower barrier layer 34 and the upper barrier layer 37 can correspond to the inhibitor ALD-TiSiN film of the lower portion and the inhibitor ALD-TiN or ALD-TiN film structure of the upper portion. Figures 2 to 7 ALD-TiSiN film of the lower portion and the upper electrode layer 39 can correspond to the inhibitor ALD-TiN or ALD-TiN film of the upper portion. Figure 6 ALD-TiN or ALD-TiN film of the upper portion. Figure 7 ALD-TiN or ALD-TiN film of the upper portion.

[0110] Thus, it can be known that the inhibitor ALD-TiSiN film manufactured according to the above-described embodiments of the present application can be used as a lower electrode or an upper electrode for a diffusion preventing film in a capacitor of a DRAM device.

[0111] The present application has been described with reference to the embodiments illustrated in the drawings, but this is only exemplary, and as long as it can be understood by those having ordinary knowledge in the art that various modifications and equivalent embodiments can be implemented therefrom. Thus, the true technical scope of the present application should be defined by the technical idea of the claims.

Claims

1. A method for forming a thin film, utilizing a substrate processing apparatus, the substrate processing apparatus comprising: Process chambers provide reaction space inside; A substrate support is provided in the process chamber for placing the substrate on top; A gas injection unit supplies process gas to the substrate support within the reaction space; The thin film formation method includes the following steps: The substrate is placed on the substrate support within the process chamber; On the substrate, ALD-TiSiN units using inhibitors are cycled repeatedly to form an ALD-TiSiN thin film by atomic layer deposition. The ALD-TiSiN unit cycle using the inhibitor includes the following steps: The ALD-TiN unit is cycled at least once to form an ALD-TiN layer on the substrate; and The enhanced ALD-SiN unit without inhibitors is cycled at least once to implant Si elements onto the ALD-TiN layer. The ALD-TiN unit cycle utilizing the inhibitor includes: The step of supplying at least one inhibitor and source on the substrate includes, in sequence or in reverse order, an inhibitor supply step and a titanium-containing gas supply step; and The step of supplying nitrogen-containing reactive gas to the substrate at least once, An additional pulsed purge gas supply step is added after the inhibitor supply step, the titanium-containing gas supply step, and the reactant gas supply step. The ratio of the number of cycles of the inhibitor-based ALD-TiN unit cycle to the number of cycles of the enhanced ALD-SiN unit cycle without the inhibitor is in the range of 3:1 to 8:

1.

2. The thin film forming method according to claim 1, characterized in that, After the inhibitor supply step, after the titanium-containing gas supply step, and after the reactant gas supply step, increase the opening ratio of the throttle valve in the process chamber. During the pulsed purge gas supply step, the opening ratio of the throttle valve is maintained at an increased level. After supplying the pulsed purge gas, the opening ratio of the throttle valve is reduced again.

3. The thin film forming method according to claim 1, characterized in that, The enhanced ALD-SiN unit cycle includes the following steps: Silicon-containing gas is supplied to the substrate at least once; At least one nitrogen-containing reaction gas is supplied to the substrate; Each step is performed while a purge gas supply is continuously provided.

4. The thin film forming method according to claim 3, characterized in that, In the enhanced ALD-SiN unit cycle, a pulsed purge gas supply step is added after the silicon-containing gas supply step and after the reactive gas supply step.

5. The thin film forming method according to claim 4, characterized in that, Increase the opening ratio of the throttle valve in the process chamber after the silicon-containing gas supply step and after the reaction gas supply step. During the pulsed purge gas supply step, the opening ratio of the throttle valve is maintained at an increased level. After supplying the pulsed purge gas, the opening ratio of the throttle valve is reduced again.

6. The thin film forming method according to claim 1, characterized in that, After repeatedly cycling the ALD-TiSiN unit using the inhibitor, the process includes forming an ALD-TiN thin film on the substrate using atomic layer deposition or atomic layer deposition using the inhibitor.

7. The thin film forming method according to claim 6, characterized in that, The thickness of the ALD-TiN film is within Within the range.

8. The thin film forming method according to claim 1, characterized in that, Prior to the step of repeatedly cycling the ALD-TiSiN unit using the inhibitor, the step includes forming an ALD-TiN thin film on the substrate using atomic layer deposition or atomic layer deposition using the inhibitor.

9. The thin film forming method according to claim 8, characterized in that, The thickness of the ALD-TiN film is within Within the range.

10. The thin film forming method according to claim 1, characterized in that, The inhibitor contains vapors of an organic solvent containing carbon and chlorine; The titanium-containing gas includes TiCl4 vapor; The reactant gas contains NH3 gas.

11. The thin film forming method according to claim 3, characterized in that, The silicon-containing gas includes at least one selected from SiH4 gas and DCS gas; The reactant gas contains NH3 gas.

12. The thin film forming method according to claim 11, characterized in that, The inhibitor contains vapors of an organic solvent containing carbon and chlorine.

13. The thin film forming method according to claim 1, characterized in that, The ALD-TiSiN thin film containing the inhibitor is used as an anti-diffusion film for the lower or upper electrode inside the capacitor of a DRAM device.

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