Substrate processing method and substrate processing apparatus

Abstract

The invention discloses a substrate processing method and a substrate processing apparatus, and the substrate processing method is used for etching a thin film formed on a substrate in atomic layer units. The substrate processing method includes: a modification step of supplying a modification gas to a processing space in a chamber in which a substrate is accommodated to modify a surface of a thin film and form a modified film having a first thickness; a surface adsorption step of supplying a precursor to the processing space so that the precursor is adsorbed onto the modified surface of the film; and an etching step of supplying heat to the substrate on which the precursor has been adsorbed to etch the modified surface of the thin film on which the precursor has been adsorbed. The surface adsorption step and the etching step are repeatedly performed a plurality of times until the modified film having the first thickness is etched away.

Description

Technical Field

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus, and more particularly, to a substrate processing method capable of shortening the total process time. Background Art

[0002] With the recent demand for miniaturization and high integration of semiconductor devices, the chip area is increasing in proportion to the increase in storage capacity. However, the area of ​​the unit area actually used to form the semiconductor device pattern has been reduced. Therefore, in order to ensure the required storage capacity, it is necessary to form as many patterns as possible in a limited unit area. Therefore, the critical dimension of the pattern is gradually decreasing. It is necessary to accurately control the etching process to form a pattern with a reduced critical dimension.

[0003] Generally, etching processes can be divided into wet etching and dry etching according to the etching method. Wet etching is isotropic etching using chemical reactions. It has the advantages of low cost and simple process, but it is difficult to achieve precise etching and chemical contamination occurs. In particular, wet etching has the disadvantage that it is difficult to form fine patterns due to etching errors.

[0004] To solve the above problems, dry etching can be used. Dry etching is an etching method that uses reactive gas particles in a plasma state. Dry etching is anisotropic etching and can achieve precise etching, so it is widely used to manufacture fine pattern substrates, such as high-density integrated circuits.

[0005] Atomic layer etching (ALE), as one of the dry etching methods, can include a cycle consisting of surface modification (or adsorption), purging, desorption and purging, and can etch the object to be etched through the adsorption and desorption process. Theoretically, one cycle can etch one atomic layer, and the cycle can be repeated until the desired depth is reached. In addition, atomic layer etching is self-limiting, that is, the reaction automatically stops when the surface is saturated, so it has the advantage of being able to accurately remove the desired amount of layer.

[0006] However, atomic layer etching has disadvantages of very long process time and low productivity. Summary of the invention

[0007] The present invention aims to solve the above-mentioned problem, and an object of the present invention is to provide a substrate processing method capable of shortening the atomic layer etching process time.

[0008] The objectives to be achieved by the present invention are not limited to the above objectives, and a person skilled in the art will clearly understand other objectives not mentioned herein from the following description.

[0009] According to one aspect of the present invention, the above-mentioned purpose and other purposes can be achieved by providing a substrate processing method for etching a thin film formed on a substrate in units of atomic layers, the substrate processing method comprising: a modification step, in which a modification gas is supplied to a processing space in a chamber that accommodates a substrate to modify the surface of the thin film and form a modified film having a first thickness; a surface adsorption step, in which a precursor is supplied to the processing space so that the precursor is adsorbed onto the modified surface of the thin film; and an etching step, in which heat is supplied to the substrate adsorbed with the precursor to etch the modified surface of the thin film adsorbed with the precursor, wherein the surface adsorption step and the etching step are repeated multiple times until the modified film having the first thickness is etched away.

[0010] In one embodiment, the substrate processing method may further include a first determination step, in which it is determined whether the surface adsorption step and the etching step have been repeatedly performed a predetermined number of times.

[0011] In one embodiment, when it is determined in the first determining step that the surface adsorption step and the etching step have not been repeatedly performed a predetermined number of times, the method may include re-performing the surface adsorption step and the etching step.

[0012] In one embodiment, when it is determined in the first determination step that the surface adsorption step and the etching step have been repeatedly performed a predetermined number of times, the method may include a second determination step, in which it is determined whether the total etching thickness reaches the target etching thickness, and when it is determined in the second determination step that the total etching thickness does not reach the target etching thickness, the method may include re-executing the modification step.

[0013] In one embodiment, the modifying step may be controlled such that the modified film forming process is performed in the diffusion limited region.

[0014] In one embodiment, in the modifying step, the modifying gas supplied to the substrate may include at least one of oxygen, fluorine, or chlorine.

[0015] In one embodiment, the modifying step may be performed in a state where plasma is generated in the processing space.

[0016] In one embodiment, any one of trimethylamine (TMA), acetylacetone (AcAc), and hexafluoroacetylacetone (hfac) may be supplied to the substrate as a precursor so as to be adsorbed to the surface of the modified film.

[0017] In one embodiment, the modifying step may be controlled at a first temperature, the surface adsorption step may be controlled at a second temperature that is the same as the first temperature, and the etching step may be controlled at a third temperature that is higher than the first temperature and the second temperature.

[0018] According to another aspect of the present invention, there is provided a substrate processing apparatus, comprising: a first chamber configured to modify a thin film formed on a substrate; a second chamber configured to etch the substrate modified in the first chamber in units of atomic layers; a substrate transfer robot configured to transfer the substrate between the first chamber and the second chamber; and a controller, wherein the first chamber comprises: a plasma generating unit configured to generate plasma in a processing space in the first chamber; and a gas supply unit configured to selectively supply a modifying gas and a precursor to the processing space in the first chamber, the second chamber comprises a heating unit configured to supply heat to the processing space in the second chamber, and the controller is configured to: control the plasma generating unit; The control unit and the gas supply unit perform a modification step, wherein a modification gas is supplied to the processing space in the first chamber to modify the surface of the thin film of the substrate in the processing space arranged in the first chamber and form a modified film with a first thickness; the gas supply unit is controlled to perform a surface adsorption step, wherein a precursor is supplied to the processing space in the first chamber so that the precursor is adsorbed onto the modified surface of the thin film; the substrate transfer robot is controlled to transfer the substrate that has undergone the surface adsorption step to the second chamber; the heating unit is controlled to perform an etching step, wherein heat is supplied to the substrate transferred to the second chamber to etch the modified surface of the thin film adsorbed with the precursor, and control is performed so that the surface adsorption step and the etching step are repeated multiple times until the modified film with the first thickness is etched away.

[0019] In one embodiment, the modifying gas may include at least one of oxygen, fluorine or chlorine.

[0020] In one embodiment, the precursor may be any one of trimethylamine (TMA), acetylacetone (AcAc), and hexafluoroacetylacetone (hfac).

[0021] In one embodiment, the controller can control the plasma generating unit and the gas supplying unit so that plasma of the modifying gas is generated in the processing space in the first chamber to modify the surface of the thin film formed on the substrate, and the precursor is supplied so as to be adsorbed onto the modified surface of the thin film.

[0022] In one embodiment, the heating unit may be any one of an infrared lamp, a laser generator, and a microwave generator.

[0023] In one embodiment, the controller may perform control such that the modifying film forming process of the modifying step is performed in the diffusion limiting region.

[0024] In one embodiment, when the heating unit of the second chamber is driven, the controller may control the gas supply unit not to supply the gas to the second chamber.

[0025] According to another aspect of the present invention, there is provided a substrate processing method for etching a thin film formed on a substrate using a substrate processing device including a first chamber and a second chamber, the substrate processing method comprising: a modification process for modifying the thin film formed on the substrate in the first chamber, the modification process comprising: a modification step, wherein a modifying gas is supplied to a processing space in the first chamber that accommodates the substrate to modify the thin film and form a modified film having a first thickness; a first purge step, wherein a purge gas is supplied to the processing space in the first chamber to remove the modifying gas remaining in the processing space; a surface adsorption step, wherein a precursor is supplied to the processing space in the first chamber so that the precursor is adsorbed to the surface of the modified film; and a second purge step, A purge gas is supplied to the processing space in the first chamber to remove the precursor remaining in the processing space; an etching process is used to etch the thin film modified in the first chamber in units of atomic layers in the second chamber, and the etching process includes: an etching step, in which heat is supplied to the processing space in the second chamber to etch the substrate adsorbed with the precursor; and a third purge step, in which a purge gas is supplied to the processing space in the second chamber to remove the etching by-products remaining in the processing space; and a first determination step, in which it is determined whether the surface adsorption step and the etching step have been repeated a predetermined number of times, wherein when it is determined in the first determination step that the surface adsorption step and the etching step have not been repeated a predetermined number of times, the method includes re-executing the surface adsorption step and the etching step.

[0026] In one embodiment, when it is determined in the first determination step that the surface adsorption step and the etching step have been repeatedly performed a predetermined number of times, the method may include a second determination step of determining whether the total etching thickness reaches the target etching thickness, wherein when it is determined in the second determination step that the total etching thickness does not reach the target etching thickness, the method may include re-executing the modification step.

[0027] In one embodiment, the modifying step may be controlled such that the modified film forming process is performed in the diffusion limited region.

[0028] In an embodiment, the modifying gas may include any one of oxygen, fluorine, and chlorine, and the precursor may be any one of trimethylamine (TMA), acetylacetone (AcAc), and hexafluoroacetylacetone (hfac). BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 is a flow chart showing a substrate processing method according to an embodiment of the present invention;

[0031] Figure 2 is a growth curve diagram of silicon oxide film;

[0032] Figure 3 is a view of a semiconductor manufacturing apparatus according to an embodiment of the present invention;

[0033] Figure 4 is a view showing a first chamber according to an embodiment of the present invention; and

[0034] Figure 5 is a view showing a second chamber according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement these embodiments. However, the present invention can be implemented in many different forms and should not be interpreted as being limited to the embodiments described herein.

[0036] In the following description of the embodiments of the present invention, detailed descriptions of known functions or configurations incorporated herein will be omitted when they may unnecessarily obscure the subject matter of the present invention. Throughout the drawings, components performing similar functions and operations are denoted by the same reference numerals.

[0037] At least some of the terms used in this specification are defined in consideration of the functions obtained according to the present invention, and may be changed according to the intention or practice of the user or operator. Therefore, the definitions of these terms should be determined based on the entire content of this specification.

[0038] As used herein, a singular form may include a plural form unless the context clearly indicates otherwise. In addition, unless otherwise indicated, the terms "include", "comprises" or "has" described herein should not be interpreted as excluding other elements, but also include such other elements.

[0039] In the drawings, the size or shape of elements and the thickness of lines may be exaggerated for clarity and ease of description.

[0040] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Even if the same or similar elements are shown in different drawings, they are denoted by the same reference numerals and their repeated description will be omitted.

[0041] The substrate of the embodiment of the present invention may be a silicon substrate based on a semiconductor wafer, or a silicon substrate with a thin film formed thereon. The thin film of the embodiment of the present invention may be a metal film or an insulating film.

[0042] Figure 1 is a flow chart of a substrate processing method according to an embodiment of the present invention, Figure 4 and Figure 5 2 is a diagram showing a first chamber and a second chamber configured to perform a substrate processing method of the present invention. Figure 1 , Figure 4 and Figure 5 The substrate processing method of the present invention is described.

[0043] refer to Figure 1 , Figure 4 and Figure 5 , according to an embodiment of the present invention, the method for etching a thin film formed on a substrate in units of atomic layers may include: a modification step S120, supplying a modification gas to a processing space in a chamber where a substrate is placed to modify the surface of the thin film and form a modified film having a first thickness; a first purge step S140, supplying a purge gas to the processing space to remove the residual modification gas in the processing space; a surface adsorption step S160, supplying a precursor to the processing space so that the precursor is adsorbed on the modified surface of the thin film; a second purge step S180, supplying a purge gas to the processing space to remove the residual precursor in the processing space; an etching step S220, supplying heat to the substrate adsorbed with the precursor to etch the modified surface of the thin film adsorbed with the precursor; and a third purge step S240, supplying a purge gas to the processing space to remove etching byproducts. In this case, the modification step S120 to the second purge step S180 may constitute the modification process S100, and the etching step S220 and the third purge step S240 may constitute the etching process S200. In addition, according to an embodiment of the present invention, the modifying process S100 may be performed in the first chamber 200 a , and the etching process S200 may be performed in the second chamber 200 b .

[0044] In the modification step S120, a modification gas may be supplied to a processing space in the first chamber 200a where the substrate W is placed. The gas supply unit 500 may supply the modification gas, and the supplied modification gas may be converted into plasma and then supplied to the substrate W. The modified gas converted into plasma may react with the thin film formed on the substrate W to form a modified film having a first thickness. The modification gas of the embodiment of the present invention may include any one of oxygen (O), fluorine (F) and chlorine (Cl). The modification step S120 may be performed at a first temperature, which may be room temperature.

[0045] Unlike the general atomic layer etching in which the modification process S100 and the etching process S200 are each performed once, the present invention is characterized in that the modification process S100 is performed in such a manner that the modification step S120 is performed once, and then the surface adsorption step S160 and the etching step S220 are repeatedly performed multiple times. To this end, according to the present invention, a modified film having a predetermined thickness can be formed in the modification step S120.

[0046] In order to form a modified film having a predetermined thickness in the modifying step S120, a growth curve of the modified film with modification time may be obtained in advance and then used. For example, if the modified film is a silicon oxide film, a growth curve of the silicon oxide film with process time may be used.

[0047] Figure 2 This is the growth curve of silicon oxide film.

[0048] See also Figure 2 , when an oxide film is formed on a silicon substrate, the thickness of the oxide film increases linearly with time at the beginning of the reaction, and then increases parabolically with time. This is because the thickness of the oxide film is relatively small at the beginning of the reaction, so the growth rate of the oxide film is determined by the reaction rate at the interface between the oxide film and silicon, but when the thickness of the oxide film increases to a certain extent, the growth rate of the oxide film is determined by the diffusion rate through the oxide film (rather than the reaction rate at the interface between the oxide film and silicon). In this case, the area where the growth rate of the oxide film is determined by the reaction rate will be called the "surface reaction limited area", and the area where the growth rate of the oxide film is determined by the diffusion rate will be called the "diffusion limited area". Therefore, when the modified film is an oxide film, it can be obtained experimentally Figure 2 The growth curve diagram shown in FIG. 1 is then used to form a modified film having a predetermined thickness using a modification time corresponding to the target thickness of the modified film.

[0049] In the present invention, the modified film is formed to have a sufficient thickness, and preferably in a diffusion-limited region where the thickness can be relatively accurately controlled. That is, it is preferred to form the modified film in a region equal to or longer than Figure 2 A modified film having a predetermined thickness is formed within the modification process time corresponding to the time at which the linear increase portion and the parabolic increase portion in the graph intersect.

[0050] The thickness of the modified film can be measured using an ellipsometer. 2 The plasma was kept on for about 12 seconds, and the thickness of the formed silicon oxide film (modified film) was measured using an ellipsometer. The measurement results showed that the thickness of the formed silicon oxide film was about It can be seen from the above experimental results that in the modifying step S120 , the surface layer of the substrate W is modified and a modified film having a predetermined thickness is formed.

[0051] The first purge step S140 is a step of supplying a purge gas through the gas supply unit 500 to remove the modified gas remaining in the processing space in the first chamber 200a. After the supply of the modified gas is interrupted, the purge gas can be directly supplied to the processing space in the first chamber 200a without using plasma. Due to the supply of the purge gas, the modified gas and reaction byproducts remaining in the processing space in the first chamber 200a after being supplied in the modification step S120 can be removed from the processing space. An inert gas (such as argon (Ar), helium (He) or nitrogen (N 2 )) as purge gas.

[0052] The surface adsorption step S160 is a step of supplying a precursor to the processing space in the first chamber 200a using the gas supply unit 500 so that the precursor is adsorbed to the surface of the film modified in the modification step S120. The precursor is physically adsorbed to the surface layer of the modified film. Thereafter, through the ligand exchange reaction, the modified film formed on the substrate W is not etched, but the binding energy can be weakened compared to before the surface adsorption step S160 is performed. The precursor according to an embodiment of the present invention may be any one of trimethylamine (TMA), acetylacetone (AcAc) and hexafluoroacetylacetone (hfac). However, the present embodiment is not limited thereto. The surface adsorption step S160 may be performed at a second temperature, and the second temperature may be room temperature.

[0053] The second purge step S180 is a step of supplying a purge gas through the gas supply unit 500 to remove the precursor remaining in the processing space in the first chamber 200a. After the supply of the precursor is interrupted, the purge gas may be directly supplied to the processing space in the first chamber 200a without using plasma. Due to the supply of the purge gas, the precursor and reaction byproducts remaining in the processing space in the first chamber 200a after being supplied in the surface adsorption step S160 may be removed from the processing space. An inert gas such as argon (Ar), helium (He), or nitrogen (N 2 )) as purge gas.

[0054] The etching step S220 is a step of etching a thin film in units of atomic layers by supplying heat to a processing space in the second chamber 200b where the substrate W that has undergone the modification process S100 is placed. The gas supply unit 500 may not supply gas to the processing space in the second chamber 200b, but may use the heating unit 600 to supply heat to the substrate W, thereby etching the thin film in units of atomic layers. In the etching step S220, the surface layer of the modified film to which the precursor is adsorbed in the surface adsorption step S160 is etched. The etching step S220 according to an embodiment of the present invention may be performed at a third temperature, which may be 250° C. to 400° C. The infrared lamp 610 may be used to supply heat to the substrate W. Heat may be supplied to the substrate W using the heating unit 600 to etch a thin film formed on the substrate W, wherein the substrate W has a binding energy weakened by the precursor physically adsorbed to the surface layer of the modified film in the surface adsorption step S160.

[0055] The third purge step S240 is a step of supplying a purge gas through the gas supply unit 500 to remove the etching byproducts remaining in the processing space in the second chamber 200b. After the heat supply is interrupted, the purge gas can be directly supplied to the processing space in the second chamber 200b without using plasma. Due to the supply of the purge gas, the etching byproducts remaining in the processing space after being generated in the etching step S220 can be removed. An inert gas (such as argon (Ar), helium (He) or nitrogen (N 2 )) as purge gas.

[0056] Subsequently, the first determination step S300 may be performed to determine whether the preset number of conditions is met. Specifically, the number of treatments to be performed according to the substrate processing method may be preset and stored in the storage device of the controller 700 for use in the control program. In one example, the number of repetitions of performing the surface adsorption step S160 to the third purge step S240 may be set in the controller 700 based on the thickness of the modified film formed in the modification step S120 and the etching thickness of the film in one cycle including the surface adsorption step S160 to the third purge step S240, so as to completely etch the modified film formed in the modification step S120.

[0057] For example, if the thickness of the modified film formed in the modifying step S120 is about And the film etching thickness by performing one cycle including the surface adsorption step S160 to the third purge step S240 is about Then, the number of repetitions from the surface adsorption step S160 to the third purge step S240 can be set to 11 times in the controller 700, and the controller 700 can process according to the set number of repetitions. If the set number of repetitions is not reached, it means that the modified film formed in the modification step S120 has not been completely etched, so the process can return to the surface adsorption step S160, and the process from the surface adsorption step S160 to the third purge step S240 can be repeated. If the set number of repetitions is reached, it means that the modified film formed in the modification step S120 has been completely etched, so the process can enter the next step, that is, the second determination step S400.

[0058] The second determination step S400 is a step of determining whether the film has been etched to a preset target etching thickness. If the film has not been etched to a preset target etching thickness, the process may return to the modification step S120, and the modification step S120 to the third purge step S240 may be performed. Here, the second determination step S400 of determining whether the film has been etched to a target etching thickness may be a step of determining whether the number of executions of the modification step has reached a preset number of modification times. For example, if the target etching thickness is The thickness of the modified film formed in the modification step S120 is It may be determined whether the number of modification steps has reached three times. If the number of modification steps has not reached three times, the process may return to the modification step S120, and if the number of modification steps has reached three times, the etching process may be terminated.

[0059] In this way, in the process of performing the process according to the above method, the number of executions from the modifying step S120 to the first purging step S140 can be reduced, thereby shortening the total process time.

[0060] As described above, a modification process can be performed in a first chamber, wherein a modification gas converted into plasma is supplied to form a modified film having a predetermined thickness and a precursor is supplied so that it is adsorbed on the surface of the substrate, and an etching process can be performed in a second chamber, wherein heat is supplied to etch the modified substrate. Thereafter, the modified film formed on the substrate and the modified film etched to a certain extent by performing one etching process cycle can be compared with each other by a determination step. According to the present invention, if it is determined in the first determination step that the modified film formed on the substrate in the modification step has not been completely etched, the process can return to the surface adsorption step, and the surface adsorption step and subsequent steps can be performed. If it is determined in the second determination step that the modified film on the substrate formed in the modification step has been completely etched, the process can return to the modification step, and the modification process and the etching process can be performed. Therefore, the total process time can be shortened, thereby improving productivity. In addition, since the modification process and the etching process are performed at different temperatures, the deformation of the substrate due to temperature can be minimized.

[0061] Figure 3 is a plan view of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

[0062] See also Figure 3 , the semiconductor manufacturing equipment 1 may include an index module 10, a process module 20, and a substrate transfer module 30, and the substrate transfer module 30 is configured to transfer a substrate between the index module 10 and the process module 20. According to an embodiment of the present invention, the index module 10 and the process module 20 may be sequentially arranged in a row.

[0063] The index module 10 may include a load port 12, a carrier C storing substrates is located on the load port 12, and an index rack 14 is used to take out a substrate from the carrier C located on the load port 12 or transfer a processed substrate to the carrier C. The load port 12 is located opposite to the process module 20 relative to the index rack 14. A plurality of carriers C storing substrates may be placed on the load port 12.

[0064] An indexing robot 144 may be provided in the indexing rack 14. The indexing robot 144 may be formed to be movable along the rail 142. The indexing robot 144 may be used to receive a substrate from a carrier C and transfer the substrate to a load lock chamber 15 configured to temporarily store the substrate or to receive a substrate temporarily stored in the load lock chamber 15 and transfer the substrate to the carrier C.

[0065] The processing module 20 may be a device for processing a substrate. The processing module 20 may include one or more processing chambers 200. A plurality of processing chambers 200 may be provided. Each processing chamber 200 may perform the same process or may perform different processes. Figure 4 and Figure 5 According to an embodiment of the present invention, the first chamber 200a may perform a modification process for modifying a substrate, and the second chamber 200b may perform an etching process for etching the modified substrate. These processing chambers 200a and 200b will be described in more detail later. Although the first chamber 200a and the second chamber 200b are shown as being arranged adjacent to each other to perform a process according to an embodiment of the present invention, the present embodiment is not limited thereto. In an example, the first chamber 200a and the second chamber 200b may be arranged opposite to each other or may be arranged in a colinear manner at a predetermined interval.

[0066] The substrate transfer module 30 may be disposed near the process module 20, and is used to receive a substrate from the load lock chamber 15 and transfer the substrate to the process module 20, or transfer a substrate processed from the process module 20 to the load lock chamber 15. The substrate transfer module 30 may include a track 330 arranged along the arrangement direction of the process chamber 200 and a substrate transfer robot 340 configured to transfer the substrate while moving along the track 330. The substrate transfer robot 340 may transfer the substrate while moving in the internal space of the transfer chamber 310.

[0067] Figure 4 is a schematic cross-sectional view of a first chamber according to an embodiment of the present invention.

[0068] See also Figure 4 , the first chamber 200 a may include a substrate supporting unit 300 , a plasma generating unit 400 , a gas supplying unit 500 , and a controller 700 .

[0069] The first chamber 200a may include a processing space defined in the first chamber 200a to allow a plasma process to be performed therein. The first chamber 200a may include an exhaust port 202 formed at its lower side. The exhaust port 202 may be connected to an exhaust line installed with a pump P. The exhaust port 202 may discharge reaction byproducts generated during the plasma process and gases remaining in the first chamber 200a to the outside of the first chamber 200a through the exhaust line. In this case, the pressure in the internal space in the first chamber 200a may be reduced to a predetermined pressure.

[0070] The first chamber 200a may include an opening 204 formed in a sidewall thereof. The opening 204 may be used as a passage for introducing or removing a substrate W into or from the first chamber 200a. The opening 204 may be configured to be opened and closed by a door assembly.

[0071] The substrate supporting unit 300 may be disposed in a lower region of the first chamber 200a. The substrate supporting unit 300 may support the substrate W using electrostatic force. However, the present embodiment is not limited thereto. The substrate W may be supported in various ways, such as mechanical clamping or vacuum support.

[0072] The substrate supporting unit 300 may include a supporting body 302 and an electrostatic chuck 304 disposed on an upper surface of the supporting body 302. The electrostatic chuck 304 may be configured to electrostatically adsorb and hold the substrate W, and may include a ceramic layer provided with an electrode.

[0073] According to an embodiment of the present invention, although not shown, a heating part and a cooling part may be provided in the substrate supporting unit 300 to maintain the substrate W at a process temperature. The heating part may be a heating coil, and the cooling part may be a cooling line through which a refrigerant flows.

[0074] A susceptor 306 may be disposed under the support body 302 to support the support body 302 and the electrostatic chuck 304. The susceptor 306 may be formed in a cylindrical shape having a predetermined height, and may have a space defined therein.

[0075] The plasma generating unit 400 may generate plasma in the processing space in the first chamber 200a. Plasma may be generated in the region above the substrate supporting unit 300 in the first chamber 200a. According to an embodiment of the present invention, the plasma generating unit 400 may generate plasma in the processing space in the first chamber 200a using a capacitively coupled plasma (CCP) source.

[0076] However, the present embodiment is not limited thereto. The plasma generating unit 400 may also generate plasma in the processing space in the first chamber 200a using another type of plasma source, such as an inductively coupled plasma (ICP) source or microwaves.

[0077] The plasma generating unit 400 may include a high frequency power supply 402 and a matching device 404. The high frequency power supply 402 may supply high frequency power to any one of the upper electrode and the lower electrode to generate a potential difference between the upper electrode and the lower electrode. Here, the upper electrode may be the showerhead 410, and the lower electrode may be the substrate supporting unit 300.

[0078] The showerhead 410 may be disposed in the first chamber 200a so as to be vertically opposed to the electrostatic chuck 304. The showerhead 410 may include a plurality of gas injection holes formed therein to uniformly inject gas into the interior of the first chamber 200a, and may be formed to have a larger diameter than the electrostatic chuck 304. The showerhead 410 may be made of a material including a silicon component or a material including a metal component.

[0079] The gas supply unit 500 may supply the gas required for the process to the inside of the first chamber 200a. The gas supply unit 500 may include a gas source, a gas supply line, and a gas nozzle. The gas supply line may connect the gas source to the gas nozzle. The gas supply line may supply the gas stored in the gas source to the gas nozzle. A gas valve may be installed on the gas supply line to open or close a channel of the gas supply line, or to adjust the flow rate of a fluid flowing through the channel.

[0080] The gas supply unit 500 of the embodiment of the present invention may include a plurality of gas sources 502 , 512 , 522 for supplying modifying gas, precursor and inert gas, a plurality of gas supply pipelines 504 , 514 , 524 and a plurality of gas valves 506 , 516 , 526 .

[0081] The gas source 502 for supplying the modifying gas can supply any one of oxygen, fluorine and chlorine to the processing space in the first chamber 200 a through the gas supply line 504 to modify the substrate W, thereby forming a modified film. A gas valve 506 for adjusting the flow rate of the supplied modifying gas can be provided on the gas supply line 504 .

[0082] The gas source 512 for supplying the precursor can supply any one of trimethylamine (TMA), acetylacetone (AcAc), and hexafluoroacetylacetone (hfac) to the modified film formed by the modified gas in the processing space in the first chamber 200a through the gas supply line 514. A gas valve 516 for adjusting the flow rate of the supplied precursor can be provided on the gas supply line 514.

[0083] The gas source 522 for supplying the purge gas may supply the purge gas to the processing space in the first chamber 200a through the gas supply line 524 after the supply of the modifying gas and the precursor is interrupted. A gas valve 526 for adjusting the flow rate of the supplied purge gas may be provided on the gas supply line 524. The purge gas may be an inert gas, such as argon (Ar), helium (He), or nitrogen (N 2 ).

[0084] The controller 700 may control so that the modified gas is supplied to the processing space in the first chamber 200a configured as described above and converted into plasma by the plasma generating unit 400. In addition, the controller 700 may control so that the gas supply unit 500 supplies the precursor to the processing space and the plasma generating unit 400 does not operate.

[0085] In addition, the controller 700 may control so that the substrate W that has undergone the modification step and the surface adsorption step is transferred to the second chamber 200b so as to etch the substrate W in units of atomic layers. Specifically, in the first chamber 200a, a modification gas may be supplied to modify the substrate W so as to form a modified film, and a precursor may be supplied so as to be adsorbed on the surface of the modified film. Subsequently, the substrate W that has undergone the modification step and the surface adsorption step may be transferred to the second chamber 200b by the substrate transfer robot 340 of the substrate transfer module 30, and then the modified substrate W may be etched in units of atomic layers. When the substrate W is transferred from the first chamber 200a to the second chamber 200b, the substrate transfer module 30 may be maintained in a vacuum state.

[0086] Figure 5 2 is a view showing a second chamber according to an embodiment of the present invention. The second chamber may perform a process of etching a modified substrate in units of atomic layers using an inert gas and heat instead of plasma.

[0087] See also Figure 5, the second chamber 200b and Figure 5 The first chamber 200a shown in FIG. Figure 4 The embodiment of FIG. 6 is different in that the process of etching the substrate W is performed using the heating unit 600 (instead of plasma).

[0088] A heating unit 600 may be provided at the upper side of the second chamber 200b to provide heat to the substrate W having the precursor adsorbed to the modified film surface, thereby etching the substrate W in units of atomic layers. The heating unit 600 may include a plurality of heating lamps 610 configured to generate thermal energy and may provide heat to the substrate W placed below the heating unit 600 to be opposite to the heating unit 600. The heating lamp 610 according to an embodiment of the present invention may be an infrared lamp and may provide heat of 250° C. to 400° C. to the substrate W.

[0089] A window 620 may be provided between the heating lamp 610 and the substrate support unit 300. The window 620 may be used to prevent etching byproducts generated during the process from being deposited on the heating lamp 610. For example, the window 620 may be a dielectric window. The window 620 may transmit the wavelength of light generated by the heating lamp 610, thereby supplying heat to the substrate W. According to the present invention, the surface of the substrate W on which the precursor is adsorbed may be etched in units of atomic layers using the heat supplied by the heating unit 600.

[0090] The second chamber 200b of the present invention having the above structure may be a rapid thermal processing (RTP) device, which may be used in situations where rapid temperature rise is required in a short time. In addition, the heating unit 600 disposed in the second chamber 200b is not limited to an infrared lamp, and may also include other types of thermal processing devices capable of rapid thermal processing. For example, the heating unit 600 may include a microwave generator or a laser generator.

[0091] The controller 700 may control such that the gas supply unit 500 does not supply the inert gas while the heating unit 600 supplies heat to the substrate W disposed in the processing space in the second chamber 200 b .

[0092] In addition, the controller 700 can uniformly control the operation of the first chamber 200a and the second chamber 200b configured as described above. The controller 700 can be, for example, a computer, and can include a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), and an auxiliary storage device. The CPU can operate according to the program or process conditions stored in the ROM or the auxiliary storage device to control the overall operation of the device. In addition, the computer-readable program required for the control can be stored in a storage medium. The storage medium can include, for example, a floppy disk, a compact disk (CD), a CD-ROM, a hard disk, a flash memory, a DVD, etc.

[0093] The controller 700 according to the embodiment of the present invention can compare the thickness of the modified film formed in the modification step with the film etching thickness during the surface adsorption step to the third purge step, and can preset the number of repetitions of performing the surface adsorption step to the third purge step based on this. If the set number of repetitions has been reached, the controller 700 can transfer the substrate W that has been etched to the first chamber 200a, and can re-execute the modification step. If the set number of repetitions has not been reached, the controller 700 can transfer the substrate W to the first chamber 200a, and can re-execute the surface adsorption step.

[0094] Although the first chamber 200a and the second chamber 200b according to the embodiment of the present invention have been described as performing the modification process and the etching process, respectively, the present embodiment is not limited thereto. In an example, when the plasma generating unit 400 and the heating unit 600 are both provided in one chamber, the chamber may perform both the modification process and the etching process.

[0095] As can be seen from the above description, according to the present invention, a thin film formed on a substrate can be modified to form a modified film having a predetermined thickness, and the surface adsorption step and the etching step can be repeated multiple times, thereby shortening the total process time and improving productivity.

[0096] Effects achievable by the present invention are not limited to the above-mentioned effects, and other effects not mentioned herein will be clearly understood by those of ordinary skill in the art from the above description.

[0097] It is obvious to those skilled in the art that various changes in form and detail may be made without departing from the essential features of the invention described herein. Therefore, the above detailed description should not be interpreted as limiting the present invention in all aspects, but should be regarded as examples. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all equivalent modifications made without departing from the present invention should be included within the scope of the appended claims.

Claims

1. A substrate processing method for etching a thin film formed on a substrate in units of atomic layers, the substrate processing method comprising: a modifying step, wherein a modifying gas is supplied to a processing space in a chamber accommodating the substrate to modify the surface of the thin film and form a modified film having a first thickness; a surface adsorption step, wherein a precursor is supplied to the processing space so that the precursor is adsorbed onto the modified surface of the thin film; as well as an etching step, wherein heat is supplied to the substrate on which the precursor is adsorbed so as to etch the modified surface of the thin film on which the precursor is adsorbed, The surface adsorption step and the etching step are repeatedly performed multiple times until the modified film having the first thickness is etched away.

2. The substrate processing method according to claim 1, further comprising a first determination step of determining whether the surface adsorption step and the etching step have been repeatedly performed a predetermined number of times.

3. The substrate processing method according to claim 2, wherein when it is determined in the first determining step that the surface adsorption step and the etching step have not been repeatedly performed the predetermined number of times, the substrate processing method includes re-performing the surface adsorption step and the etching step.

4. The substrate processing method according to claim 2, wherein when it is determined in the first determination step that the surface adsorption step and the etching step have been repeatedly performed the predetermined number of times, the substrate processing method further comprises a second determination step of determining whether the total etching thickness reaches the target etching thickness, wherein when it is determined in the second determination step that the total etching thickness does not reach the target etching thickness, the substrate processing method further comprises re-executing the modification step.

5. The substrate processing method according to claim 1, wherein the modifying step is controlled so that a modified film forming process is performed in a diffusion limited region. 6 . The substrate processing method according to claim 1 , wherein in the modifying step, the modifying gas supplied to the substrate includes at least one of oxygen, fluorine, or chlorine. 7 . The substrate processing method according to claim 1 , wherein the modifying step is performed in a state where plasma is generated in the processing space. 8 . The substrate processing method according to claim 1 , wherein any one of trimethylamine (TMA), acetylacetone (AcAc) and hexafluoroacetylacetone (hfac) is supplied to the substrate as the precursor so as to be adsorbed to the surface of the modified film.

9. The substrate processing method according to claim 1, wherein the modifying step is controlled at a first temperature, The surface adsorption step is controlled at a second temperature which is the same as the first temperature, and The etching step is controlled at a third temperature higher than the first temperature and the second temperature.

10. A substrate processing device, comprising: a first chamber configured to modify a thin film formed on a substrate; a second chamber configured to etch the modified substrate in the first chamber in units of atomic layers; a substrate transfer robot configured to transfer the substrate between the first chamber and the second chamber; and Controller, The first chamber comprises: a plasma generating unit configured to generate plasma in a processing space in the first chamber; as well as a gas supply unit configured to selectively supply a modifying gas and a precursor to the processing space in the first chamber, The second chamber includes a heating unit configured to supply heat to a processing space in the second chamber, and The controller is configured as: controlling the plasma generating unit and the gas supplying unit to perform a modifying step in which the modifying gas is supplied to the processing space in the first chamber to modify the surface of the thin film of the substrate disposed in the processing space in the first chamber and form a modified film having a first thickness, controlling the gas supply unit to perform a surface adsorption step in which the precursor is supplied to the processing space in the first chamber so that the precursor is adsorbed onto the modified surface of the thin film, controlling the substrate transfer robot to transfer the substrate after the surface adsorption step to the second chamber, controlling the heating unit to perform an etching step, wherein heat is supplied to the substrate transferred to the second chamber to etch the modified surface of the thin film on which the precursor is adsorbed, and Control is performed so that the surface adsorption step and the etching step are repeatedly performed a plurality of times until the modified film having the first thickness is etched away. 11 . The substrate processing apparatus according to claim 10 , wherein the modifying gas comprises at least one of oxygen, fluorine or chlorine. 12 . The substrate processing apparatus according to claim 10 , wherein the precursor is any one of trimethylamine (TMA), acetylacetone (AcAc), and hexafluoroacetylacetone (hfac).

13. The substrate processing device according to claim 10, wherein the controller controls the plasma generating unit and the gas supply unit so that the plasma of the modifying gas is generated in the processing space in the first chamber to modify the surface of the thin film formed on the substrate, and the precursor is supplied so as to be adsorbed onto the modified surface of the thin film. 14 . The substrate processing apparatus according to claim 10 , wherein the heating unit is any one of an infrared lamp, a laser generator, and a microwave generator. 15 . The substrate processing apparatus according to claim 10 , wherein the controller performs control so that a modified film forming process of the modifying step is performed in a diffusion limited region. 16 . The substrate processing apparatus of claim 10 , wherein the controller controls the gas supply unit not to supply gas to the second chamber when the heating unit of the second chamber is driven.

17. A substrate processing method for etching a thin film formed on a substrate using a substrate processing apparatus including a first chamber and a second chamber, the substrate processing method comprising: A modification process for modifying a thin film formed on the substrate in the first chamber, the modification process comprising: a modification step, wherein a modification gas is supplied to a processing space in the first chamber accommodating the substrate to modify the thin film and form a modified film having a first thickness; a first purge step, wherein a purge gas is supplied to the processing space in the first chamber to remove the modification gas remaining in the processing space; a surface adsorption step, wherein a precursor is supplied to the processing space in the first chamber so that the precursor is adsorbed to the surface of the modified film; and a second purge step, wherein a purge gas is supplied to the processing space in the first chamber to remove the precursor remaining in the processing space; an etching process for etching the modified thin film in the first chamber in units of atomic layers in the second chamber, the etching process comprising: an etching step in which heat is supplied to a processing space in the second chamber to etch the substrate on which the precursor is adsorbed, and a third purge step in which a purge gas is supplied to the processing space in the second chamber to remove etching byproducts remaining in the processing space; and a first determination step in which it is determined whether the surface adsorption step and the etching step have been repeatedly performed a predetermined number of times, When it is determined in the first determining step that the surface adsorption step and the etching step have not been repeatedly performed for the predetermined number of times, the substrate processing method further includes re-performing the surface adsorption step and the etching step.

18. The substrate processing method according to claim 17, wherein when it is determined in the first determining step that the surface adsorption step and the etching step have been repeatedly performed the predetermined number of times, the substrate processing method further comprises a second determining step of determining whether the total etching thickness reaches a target etching thickness, When it is determined in the second determining step that the total etching thickness does not reach the target etching thickness, the substrate processing method further includes re-performing the modifying step.

19. The substrate processing method according to claim 18, wherein the modifying step is controlled so that a modified film forming process is performed in a diffusion limited region.

20. The substrate processing method according to claim 17, wherein the modifying gas comprises any one of oxygen, fluorine and chlorine, and the precursor is any one of trimethylamine (TMA), acetylacetone (AcAc) and hexafluoroacetylacetone (hfac).

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