Substrate processing device and method for using substrate processing device

Abstract

According to one embodiment of the present invention, a method for using a substrate processing apparatus is provided, the apparatus comprising: a chamber having an inner wall on which a fluorine-containing / silicon salt is deposited through an oxide film removal process on a substrate disposed therein; and an antenna disposed outside the chamber; RF power is applied to the chamber to supply an inert gas into the chamber, and RF power is applied to the antenna, thereby heating the inner wall of the chamber to above 75° C. and thermally decomposing the fluorine-containing / silicon salt.

Description

Technical Field

[0001] The present invention relates to a substrate processing device and a method for using the substrate processing device, and more particularly to a substrate processing device capable of removing fluorine / silicon salt deposited on the inner wall of a chamber and a method for using the substrate processing device. Background Art

[0002] During the manufacturing process of semiconductors, displays, solar cells, and other electronic products, native oxides are typically formed on the substrate surface when it is exposed to oxygen and / or moisture in the atmosphere. Exposure to oxygen occurs when the substrate is moved between process chambers under atmospheric or ambient conditions, or when a small amount of oxygen remains in the process chamber. Native oxides can also form due to contamination during the etching process. Native oxide films are generally Very thin, but thick enough to cause difficulties in subsequent manufacturing steps. Therefore, it is generally undesirable to have a native oxide layer, which needs to be removed before subsequent manufacturing steps.

[0003]

Prior technical literature

[0004] [Patent Literature]

[0005] (Patent Document 0001) Korean Patent Application Publication No. 2005-0074241 (July 18, 2005) Summary of the Invention

[0006] Technical issues to be solved

[0007] The object of the present invention is to provide a substrate processing apparatus and a method for using the substrate processing apparatus, which can remove fluorine / silicon salts deposited on the inner wall of a chamber during the process of removing oxides formed on the surface of the substrate.

[0008] Another object of the present invention is to provide a substrate processing apparatus capable of removing fluorine-containing / silicon salts in situ and a method for using the substrate processing apparatus.

[0009] Other objects of the present invention will become more apparent from the following detailed description and accompanying drawings.

[0010] Problem Solutions

[0011] According to a method for using a substrate processing device according to one embodiment of the present invention, the substrate processing device includes: a chamber, wherein a fluorine / silicon salt is deposited on the inner wall thereof through an oxide film removal process of a substrate disposed therein; and an antenna, disposed outside the chamber and to which RF power is applied. Inert gas is supplied to the interior of the chamber, and RF power is applied to the antenna, thereby heating the inner wall of the chamber to above 75° C. and thermally decomposing the fluorine / silicon salt.

[0012] The inert gas may be argon.

[0013] In the step of applying RF power to the antenna, an application time for applying the RF power and a suspension time for suspending the application of the RF power may be periodically repeated.

[0014] The application time may be longer than the interruption time.

[0015] The above method, before supplying the above-mentioned inert gas and applying RF power to the above-mentioned antenna, includes: supplying source gas into the above-mentioned cavity and applying RF power to the above-mentioned antenna in a state where the substrate is placed on the substrate supporting table set in the above-mentioned cavity, thereby generating reactive gas from the above-mentioned source gas, and supplying the above-mentioned reactive gas to the surface of the above-mentioned substrate so that it reacts with the oxide film formed on the surface of the above-mentioned substrate; and leading the above-mentioned substrate out of the above-mentioned cavity, transferring it to an annealing treatment chamber, and heating the above-mentioned substrate to above 80°C in the above-mentioned annealing treatment chamber.

[0016] According to one embodiment of the present invention, a substrate processing apparatus includes: a chamber having an internal space; a substrate support table disposed in the internal space and having a substrate placed on top; an antenna disposed outside the chamber and applying RF power; a gas supply mechanism capable of supplying an inert gas and a source gas into the chamber; and a controller electrically connected to the gas supply mechanism and the antenna and capable of applying RF power to the antenna. The controller operates in the following purification mode: supplying an inert gas into the chamber and applying RF power to the antenna to heat the inner wall of the chamber to above 75°C, thereby thermally decomposing the fluorine / silicon salt.

[0017] The effects of the invention are as follows:

[0018] According to one embodiment of the present invention, an antenna disposed outside the cavity generates plasma from an inert gas, thereby increasing the temperature of the cavity inner wall and removing fluorine / silicon salts deposited on the cavity inner wall.

[0019] In particular, the antenna is provided to generate reactive gas from the source gas during the process of removing oxides. The temperature of the inner wall of the cavity can be increased by the antenna in the absence of other heating devices, so the fluorine / silicon salts deposited on the inner wall of the cavity can be removed in situ. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a diagram schematically showing a substrate processing apparatus according to an embodiment of the present invention.

[0021] Figure 2 It is a diagram showing the supply timing of source gas and inert gas and the RF power application timing.

[0022] Figure 3 This is a graph showing the temperature change of the inner wall of the cavity accompanying the application of RF power. DETAILED DESCRIPTION

[0023] Below, refer to the attached Figures 1 to 3 , further details are given of preferred embodiments of the present invention. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be limited to the embodiments described below. These embodiments are provided to explain the present invention in more detail to those skilled in the art. Therefore, the shapes of the elements shown in the figures may be exaggerated for clarity.

[0024] First, when the substrate is transferred and exposed to the atmosphere, oxidation (oxygenation) may occur on the substrate surface. Therefore, a cleaning step is required to remove the native oxide film (or surface oxide) formed on the substrate.

[0025] The purge process is a dry etching process using hydrogen (H*) in a free radical state and NF3 gas. For example, when etching a silicon oxide film formed on the surface of a substrate, after the substrate is placed in a chamber and a vacuum atmosphere is created within the chamber, intermediate products that react with the silicon oxide film are generated within the chamber.

[0026] For example, if hydrogen radicals (H*) and a reactive gas such as fluoride gas (NF3) are supplied into the chamber, the reactive gas is reduced to generate an intermediate product such as NHxFy (x, y are arbitrary integers) as shown in the following reaction formula (1).

[0027] H * +NF3=>NH x F y (1)

[0028] The intermediate product reacts easily with the silicon oxide film (SiO2), so when the intermediate product reaches the surface of the silicon substrate, it reacts selectively with the silicon oxide film to generate a reaction product ((NH4)2SiF6) as shown in the following reaction formula (2).

[0029] NH x F Y +SiO2=>(NH4)2SiF6+H2O (2)

[0030] Then, if the silicon substrate is heated to 80°C or higher, the reaction product is thermally decomposed into a thermal decomposition gas, which evaporates as shown in the following reaction formula (3), thereby removing the silicon oxide film from the substrate surface. As shown in the following reaction formula (3), the thermal decomposition gas includes a fluorine-containing gas such as HF gas or SiF4 gas.

[0031] (NH4)2SiF6=>NH3+HF+SiF4 (3)

[0032] As described above, the cleaning process includes a reaction process for generating a reaction product and an annealing (heating) process for thermally decomposing the reaction product. The reaction process is performed in a reaction chamber, and then the substrate is moved into an annealing chamber and the annealing (heating) process is performed.

[0033] Figure 1 This figure schematically illustrates a substrate processing apparatus according to one embodiment of the present invention. The apparatus includes a reaction chamber comprising a lower chamber 10 and an upper chamber 20. The intermediate products and reaction products described above are generated within the reaction chamber, after which the substrate is transferred to a separate annealing chamber for annealing.

[0034] The upper chamber 20 is disposed above the lower chamber 10. The lower chamber 10 has a reaction space A formed therein, and the upper chamber 20 has a production space B formed therein. The reaction space A communicates with the production space B through openings formed in the upper portion of the lower chamber 10 and the lower portion of the upper chamber 20, respectively.

[0035] A substrate support table 12 is disposed within the lower chamber 10. A substrate can be placed on top of the substrate support table 12 via a passageway (not shown) provided in the sidewall of the lower chamber 10. A baffle 14 is annular and disposed along the periphery of the substrate support table 12. The baffle 14 is supported by the baffle support table and is positioned lower than the upper surface of the substrate support table 12. Reaction byproducts and the like within the reaction space A are transported through baffle holes 14a to an exhaust port 16. A vacuum pump 18 is connected to the exhaust port 16 to forcibly exhaust the reaction byproducts and the like to the exterior of the reaction chamber.

[0036] The diffusion plate 22 is disposed between the reaction space A and the generation space B. Substances (eg, intermediate products, etc.) generated in the generation space B can move to the reaction space A through the diffusion holes 22 formed in the diffusion plate 22 .

[0037] A diffuser plate 24 is disposed above the generation space B and spaced apart from the ceiling of the upper chamber 20. Source gas and inert gas are supplied to the space spaced apart from the generation space B through supply holes 20a. The diffuser plate 24 has a plurality of injection holes 24a through which the source gas and inert gas can flow to the lower portion of the diffuser plate 24.

[0038] Multiple gas supply sources 32, 34, and 36 are moved to supply port 20a via flow controllers 32a, 34a, and 36a, respectively. The flow controllers 32a, 34a, and 36a can adjust or cut off the flow of the supplied gas. The gas supply sources 32, 34, and 36 may include a hydrogen supply source 32, a nitrogen trifluoride supply source 34, and an argon supply source 36.

[0039] Antenna 40 is cylindrical and is vertically disposed around the periphery of upper chamber 20. Antenna 40 is electrically connected to an RF power supply via controller 50, which regulates the RF power supplied to antenna 40. Controller 50 is also electrically connected to flow controllers 32a, 34a, and 36a, regulating the flow rate of gas flowing into supply hole 20a.

[0040] Figure 2 This is a diagram showing the supply time of source gas and inert gas and the RF power application time. Figure 1 and Figure 2 The method of operating the substrate processing apparatus will be described.

[0041] The substrate is moved into the lower chamber 10 and placed on the substrate supporting table 12 . The substrate is configured to be flush with the upper surface of the substrate supporting table 12 .

[0042] Then, the controller 50 supplies hydrogen from the hydrogen supply source (eg, ammonia (NH3), H2O, etc.) 32 and the nitrogen trifluoride supply source 34 to the generation space B ( Figure 2 In the 'X' interval), the source gases are hydrogen and nitrogen trifluoride. At this time, argon as an inert gas is supplied from the argon supply source 36 to the generation space B and then added to the hydrogen and nitrogen trifluoride. Argon can be replaced by other inert gases.

[0043] In addition, RF power ( Figure 2 The RF power may be approximately 500 W. Through these processes, the source gas is decomposed in the generation space B to form a reactive gas (e.g., ammonium fluoride (NH4F) or ammonium hydrogen fluoride (NH4F(HF))) as an intermediate product, which moves to the reaction space A through the diffusion hole 22 to react with the surface of the substrate containing silicon oxide.

[0044] Afterwards, the reactive gas as an intermediate product (for example, ammonium fluoride (NH4F)) reacts with the silicon oxide on the surface of the substrate in the reaction space A to form ammonium hexafluorosilicate ((NH4)2SiF6), ammonia, and water as reaction products. The ammonia and water can be removed from the reaction chamber by the vacuum pump 18.

[0045] The substrate is then transferred from the reaction chamber to an annealing chamber. Inside the annealing chamber, the substrate is heated to above 80°C, causing ammonium fluorosilicate to decompose or sublimate into volatile components such as ammonia and hydrogen fluoride. The annealing chamber is then purged and vacuum treated.

[0046] On the other hand, as previously mentioned, the reactive gas, serving as an intermediate product, reacts with silicon oxide on the substrate surface within reaction space A to produce ammonium fluorosilicate ((NH₄)₂SiF₆) as a reaction product. During this process, the reaction product is formed not only on the substrate surface but also on the inner walls of the reaction chamber. In particular, as previously mentioned, the reaction product may fall off or float, acting as a contaminant in subsequent reaction steps. Therefore, a periodic purification process is required to remove this contaminant.

[0047] In the existing chamber purification method, a fluorine-containing purification gas is supplied into the chamber. However, the reaction product is a fluorine-containing / silicon salt, which cannot be removed by the purification gas.

[0048] Figure 3 Graph showing the temperature change of the inner wall of the cavity when RF power is applied. Figure 2 After the 'X' interval) is completed and the substrate is removed from the reaction chamber, the cleaning mode ( Figure 2 The 'T1, T2, ..' interval) works. Below, refer to Figure 3 , indicating the purification mode.

[0049] First, the controller 50 closes the flow regulators 32a and 34a for the source gas to cut off the supply of the source gas, and opens the flow regulator 36 for the argon gas to supply the argon gas to the generation space B ( Figure 2 The supply amount of argon gas may be 1500 to 2500 sccm, preferably 2000 sccm.

[0050] In addition, RF power ( Figure 2 During the 'T1' interval), the RF power may be approximately 2000 W. (Pressure in the reaction chamber = 1 Torr). The RF power may be applied for approximately 150 seconds, after which the RF power may be turned off for approximately 100 seconds.

[0051] like Figure 3 As shown, through the above-described process, argon gas generates plasma within the generation space B, thereby increasing the temperature of the generation space B. That is, the generation space B can be heated by generating plasma from the argon gas. In particular, the temperature of the generation space B increases significantly at the location where the antenna 40 is located. In this case, an interruption time is required after the application time of the RF power. This interruption time also serves as a reaction time for the temperature of the generation space B to increase due to the generation of plasma.

[0052] like Figure 2 and Figure 3As shown, the purification mode ( Figure 2 The time required for one cycle is approximately 250 seconds. After the temperature of generation space B (Temp#1) reaches the desired temperature, controller 50 finally shuts off the RF power. The temperature of generation space B (Temp#1) can then be measured using a temperature detection device (not shown) installed on the inner wall of upper chamber 20.

[0053] Through the process described above, the temperature of the generation space B (Temp#1) gradually increases and can reach above 150 degrees (rising to 201 degrees when repeated 10 times). The reaction products formed on the inner wall of the generation space (B) can be decomposed or sublimated into volatile components and then forcibly discharged to the outside of the reaction chamber through the exhaust port 16.

[0054] As described above, the generation space B can be heated by generating plasma from argon gas, thereby removing reaction products formed on the inner walls of the generation space B. In particular, this method does not significantly affect the temperature of the substrate support table 12, and after purging the reaction chamber, there is no problem even if the substrate support table 12 is not cooled for subsequent steps.

[0055] On the other hand, in this embodiment, argon is used as a carrier gas / purge gas to purge the reaction chamber, but argon can also be replaced by other inert gases.

[0056] The present invention has been described in detail by using the preferred embodiments, but other embodiments are possible. Therefore, the technical concept and scope of the claims described below are not limited to the preferred embodiments.

Claims

1. A method for using a substrate processing device, characterized in that: include: supplying a reactive gas to a surface of a substrate placed on a substrate supporting table disposed in a chamber so that the reactive gas reacts with an oxide film formed on the surface of the substrate to generate a substance containing fluorine and silicon, wherein the reactive gas is generated from the source gas by supplying a source gas to the chamber and applying RF power to an antenna installed in the chamber; Leading the substrate out of the chamber and transferring it to an annealing chamber; and supplying an inert gas into the cavity and applying RF power to the antenna to heat the inner wall of the cavity to above 75° C. to thermally decompose the fluorine- and silicon-containing substances formed on the inner wall of the cavity; Applying RF power to the antenna includes an application time for applying the RF power and an interruption time for cutting off the RF power, the application time and the interruption time are repeated periodically, and the application time is longer than the interruption time.

2. The method for using a substrate processing apparatus according to claim 1, wherein: The above-mentioned inert gas is argon.

3. The method for using a substrate processing apparatus according to claim 1, wherein: Also includes: The step of heating the substrate to above 80° C. in the annealing chamber.

4. A substrate processing device, characterized in that: include: The cavity has an internal space; A substrate support platform is provided in the internal space, and a substrate is placed on the upper portion of the substrate support platform; an antenna, disposed outside the cavity, for applying RF power; A gas supply mechanism capable of supplying inert gas and source gas into the chamber; and a controller electrically connected to the gas supply mechanism and the antenna, applying RF power to the antenna, The above controller includes a processing mode and a purification mode. In the processing mode, a reactive gas is supplied to the surface of the substrate to react with the oxide film formed on the surface of the substrate to generate a substance containing fluorine and silicon, and then the substrate is led out of the chamber; In the purification mode, an inert gas is supplied to the interior of the chamber and RF power is applied to the antenna to heat the inner wall of the chamber to above 75° C., thereby thermally decomposing the fluorine- and silicon-containing substances generated on the inner wall of the chamber. Applying RF power to the antenna includes an application time for applying the RF power and an interruption time for cutting off the RF power, the application time and the interruption time are repeated periodically, and the application time is longer than the interruption time.

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