Examples are described which relate to an exhaust component cleaning method and a substrate processing apparatus including an exhaust component.
A plasma CVD apparatus includes a chamber for forming a film on a substrate by means of CVD, and an exhaust component used for discharge of a gas inside a chamber. As a result of operation of the plasma CVD apparatus, an unwanted film or by-product is formed in the chamber and the exhaust component. In order to remove such unwanted film or by-product, dry cleaning using plasma is performed on a regular basis. Such cleaning requires a long time and thus lowers productivity of the CVD apparatus. Also, the plasma for cleaning is supplied to the exhaust component through the chamber and thus may be deactivated by the time the plasma reaches the exhaust component. Therefore, cleaning of the exhaust component is difficult and time-consuming.
Some examples described herein may address the above-described problems. Some examples described herein may provide a cleaning method for efficiently cleaning an exhaust component, and a substrate processing apparatus that enables efficient cleaning of an exhaust component.
In some examples, a cleaning method includes supplying a cleaning gas into an exhaust duct that provides an exhaust flow passage of a gas supplied to an area above a susceptor, the exhaust duct having a shape surrounding the susceptor in plan view, and activating the cleaning gas to clean an inside of the exhaust duct.
Examples of an exhaust component cleaning method and a substrate processing apparatus including an exhaust component will be described with reference to the drawings. Components that are the same or correspond to each other are provided with a same reference numeral and repetitive description thereof may be omitted.
In an example, an exhaust piping 24 is provided at a side surface of the chamber 12. The exhaust piping 24 is provided for discharging a raw material gas, etc., used in substrate processing such as film formation in the chamber 12. Therefore, a vacuum pump 25 is connected to the exhaust piping 24.
The susceptor 16 is surrounded by an exhaust duct 30 having a shape surrounding the susceptor 16 in plan view. The exhaust duct 30 is formed of, for example, ceramic. In another example, the exhaust duct 30 can be an insulator. The exhaust piping 24 provides an exhaust channel that communicates with the inside of the exhaust duct 30. An O-ring 32 is provided between the exhaust duct 30 and the shower head 14. The O-ring 32 is adequately compressed as a result of being sandwiched between the exhaust duct 30 and the shower head 14. The shower head 14 is placed on the exhaust duct 30 via the O-ring 32. An O-ring 34 is provided between the exhaust duct 30 and the chamber 12. The O-ring 34 is adequately compressed as a result of being sandwiched between the exhaust duct 30 and the chamber 12. The exhaust duct 30 is placed on the chamber 12 via the O-ring 34. In an example, the exhaust duct 30 has two roles. A first role is to electrically separate the shower head 14 to which power is applied and the chamber 12 having a GND potential from each other. A second role is to guide a gas supplied to the chamber 12 to the exhaust piping 24.
In an example, a through-hole 30A is provided in an upper portion of the exhaust duct 30 and a through-hole 14A is provided in the shower head 14. The through-hole 30A and the through-hole 14A communicate with each other. A flow control ring (FCR) 31 placed on the chamber 12 is provided below the exhaust duct 30. The FCR 31 has an annular shape surrounding the susceptor 16. A gas used in substrate processing travels into the exhaust duct 30 from between the FCR 31 and the exhaust duct 30.
A transport tube 40 is connected to the shower head 14 via an insulation component 20. The transport tube 40 is a tube extending in a z-direction, that is, a substantially vertical direction. The transport tube 40 provides a substantially vertical flow passage that communicates with a diffusion space 14b above the slits 14a.
A remote plasma unit (RPU) 42 is provided at an upper end of the transport tube 40. Gas sources 44, 46 that supply a cleaning gas to be used for cleaning of the chamber 12, etc., are connected to the RPU 42. The gases supplied from the gas sources 44, 46 to the RPU 42 are brought into a plasma state or activated by the RPU 42 and thereby turn into a reactive species. The reactive species is used for cleaning of the chamber 12, etc. The gases stored in the gas sources 44, 46 are, for example, Ar and NF3.
A gas supply line 50 is connected to a side surface of the transport tube 40 substantially perpendicularly to the transport tube 40. The gas supply line 50 provides a flow passage 51 that communicates with a space 48 in the transport tube 40. A mass flow controller (MFC) 52 is connected to the gas supply line 50. Gas sources 54, 56 are connected to the MFC 52. For example, the gas sources 54, 56 are ones for supplying gases to be used for film formation. For example, the gas sources 54, 56 provide an O2 gas and a TEOS gas. The gases from the gas sources 54, 56 are subjected to pressure control by the MFC 52 and supplied to the flow passage 51, and travels through the inside of the flow passage 51 substantially horizontally and reaches the space 48 in the transport tube 40.
An RPU gate valve 62 is connected to the side surface of the transport tube 40. Upon the RPU gate valve 62 being closed, the RPU 42 and the chamber 12 are shut off from each other, enabling preventing a cleaning gas from being mixed into a raw material gas.
A gas supply tube 70 is connected to a bottom portion of the chamber 12. An MFC 72 is connected to the gas supply tube 70. A gas source 74 is connected to the MFC 72. The gas source 74 provides, for example, an O2 gas. For example, in order to suppress travel of a gas to an area below the susceptor 16, the gas being provided to an area above the susceptor 16 via the slits 14a, a gas from the gas source 74 is subjected to pressure control by the MFC 72 and supplied to the area below the susceptor 16 through the gas supply tube 70.
As an example of a cleaning gas supply configured to provide a cleaning gas into the exhaust duct 30, the cleaning gas source 39, the piping 37 that supplies a gas from the cleaning gas source 39 to the through-hole 30A, and the MFC 38 are provided.
While process plasma is generated as described above and a substrate is subjected to processing, a cleaning gas is provided to the space 30c in the exhaust duct 30 from the cleaning gas source 39 through the piping 37, the through-hole 14A and the through-hole 30A. Since the exhaust duct 30 provides an exhaust flow passage of a gas supplied to the area above the susceptor 16, process plasma that is not completely deactivated enters the space 30c. Then, the cleaning gas provided from the cleaning gas source 39 is activated by the process plasma in the exhaust duct 30. The activated cleaning gas cleans the inside of the exhaust duct 30 and is discharged through the exhaust piping 24. The activated cleaning gas can clean not only the exhaust duct 30 but also the exhaust piping 24.
As described above, in the period of the times t1 to t2, while a substrate is processed using process plasma, exhaust duct 30 is cleaned using the process plasma and a cleaning gas. Therefore, there is no waiting time for substrate processing due to cleaning.
During times t2 to t3, the processing object substrate is replaced with another or a gaseous species to be provided into between the parallel flat plates is changed. During times t3 to t4, as in the period of the times t1 to t2, while the substrate is processed using process plasma, the exhaust duct 30 is cleaned. Such processing above is repeated a given number of times.
In a period of times t5 to t6, direct cleaning is performed. In the direct cleaning, either provision of gases from the gas sources 54, 56 to the chamber nor application of high-frequency power to the shower head is performed. In the direct cleaning, the RPU gate valve 62 is opened to supply a chamber cleaning gas activated by plasma energy from the RPU 42 to the area above the susceptor 16 through the shower head 14. Consequently, the inside of the chamber 12 can be cleaned. The activated chamber cleaning gas is discharged through the exhaust duct 30 and the exhaust piping 24. Here, a cleaning gas is provided to the space 30c in the exhaust duct 30 from the cleaning gas source 39. Then, the cleaning gas is activated by the chamber cleaning gas in the exhaust duct 30 and cleans the exhaust duct 30. The activated cleaning gas can also clean the exhaust piping 24.
In an example that is different from
In both of the examples in
After repetition of substrate processing a predetermined number of times, direct cleaning is performed during times t5 to t6. In the direct cleaning, an RPU gate valve 62 is opened and a chamber cleaning gas activated by plasma energy from an RPU 42 is supplied to an area above a susceptor 16 through a shower head 14. Consequently, mainly the inside of the chamber 12 is cleaned. In an example, the direct cleaning can be terminated after confirmation of an emission intensity peak of SiF4 generated from a film remainder by Ar plasma generated by application of high-frequency power to a shower plate being sufficiently lowered.
A period of times t7 to t8 is an exhaust flow passage cleaning period. In an exhaust flow passage cleaning period, pressure inside the chamber 12 is reduced and a cleaning gas activated by the RPU 42 is supplied to the exhaust piping 24 through the inside of the chamber 12. This is expressed by the term “RPU reduced pressure cleaning” in
In an exhaust flow passage cleaning period, reducing the pressure inside the chamber to, for example, no more than 470 Pa enables suppression of retention of a cleaning gas in the chamber 12 and thus enables conveyance of a larger amount of active species to the downstream of the exhaust piping 24. In an example, the active species is an NF3 radical. If the pressure inside the chamber is excessively lowered, the RPU 42 fails to normally operate, and if the pressure inside the chamber is raised, efficiency of cleaning the inside of the chamber is increased. The pressure inside the chamber is determined in consideration of these points.
An inert gas in a neutral state, which is not a radical, is supplied from the inert gas supplier 80 to the exhaust piping 24. This inert gas conveys a radical as a carrier gas. The inert gas contributes to conveyance of an active species such as an F radical to the downstream of the exhaust piping 24 as it is in an active state. Therefore, a by-product in each of the exhaust piping 24, the vacuum pump 25 and the abatement 26 can be removed or reduced. In another example, an active species can quickly be guided to the exhaust piping 24 by supplying an inert gas from the inert gas supplier 80 into the chamber 12.
After an end of the process up to the time t8, substrate processing is resumed. The order of the direct cleaning during the times t5 to t6 and the exhaust flow passage cleaning period during the times t7 to t8 may be reversed. In direct cleaning performed before or after an exhaust flow passage cleaning period, no inert gas is supplied to the exhaust piping 24, the pressure in the chamber 12 is made to be higher than the pressure in the chamber 12 in the exhaust flow passage cleaning period and a cleaning gas activated by the RPU 42 is supplied to the chamber 12. Consequently, the inside of the chamber 12 is mainly cleaned. In direct cleaning, for example, the pressure inside the chamber is made to be around 1000 Pa.
In each of the examples in
In a test that is different from the test from which the photos in
The cleaning method described above in each of the examples particularly enhances efficiency of cleaning an exhaust component. The exhaust duct 30 and the exhaust piping 24 are examples of the exhaust component. Another exhaust component that is different from the exhaust duct 30 and the exhaust piping 24 may be provided. Examples of the exhaust component may include a bellows, a pump and an abatement.
This application is a divisional of, and claims priority to, U.S. patent application Ser. No. 18/413,533 filed Jan. 16, 2024, entitled “EXHAUST COMPONENT CLEANING METHOD AND SUBSTRATE PROCESSING APPARATUS INCLUDING EXHAUST COMPONENT,” which is a continuation of, and claims priority to, U.S. patent application Ser. No. 17/010,561, filed Sep. 2, 2020 and entitled “EXHAUST COMPONENT CLEANING METHOD AND SUBSTRATE PROCESSING APPARATUS INCLUDING EXHAUST COMPONENT,” which is a nonprovisional of, and claims priority to, U.S. Provisional Patent Application No. 62/897,243, filed on Sep. 6, 2019, in the United States Patent and Trademark Office, the disclosures of which are hereby incorporated by reference herein.
Number | Date | Country | |
---|---|---|---|
62897243 | Sep 2019 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 18413533 | Jan 2024 | US |
Child | 19077687 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 17010561 | Sep 2020 | US |
Child | 18413533 | US |