JP4591877B2 - Processing method and processing system - Google Patents

Description

  The present invention relates to a processing method for transferring a substrate to be processed to a vacuum preparatory chamber that is connected to the processing chamber via an opening / closing device and held under vacuum after processing the substrate to be processed in a processing chamber held under vacuum. And a processing system.

  In a semiconductor device manufacturing process, gas processing using a halogen-based processing gas such as dry etching or CVD is frequently used for a semiconductor wafer (hereinafter simply referred to as a wafer) that is a substrate to be processed. As a processing system for performing such gas processing, from the viewpoint of processing a plurality of wafers with high throughput, a vacuum is provided via a gate valve that is an opening / closing mechanism to a transfer chamber having a transfer arm that functions as a vacuum preparatory chamber. There is known a multi-chamber type in which a plurality of processing apparatuses for performing predetermined gas processing are connected to a substrate to be processed (for example, Patent Document 1). The processing chamber and the transfer chamber of the processing apparatus are both kept in a vacuum state, and a predetermined gas treatment is performed in the processing chamber with the gate valve closed and the both shut off. When the wafer is loaded / unloaded, the gate valve is opened and the two communicate with each other.

  In such a processing system, after the processing in the processing chamber is completed, halogen-containing gas such as processing gas or by-product gas remains in the processing chamber, and the halogen-containing gas diffuses into the transfer chamber when the gate valve is opened. As a result, the transfer chamber and the parts for transfer in the chamber may be corroded, so that it is necessary to prevent the halogen-containing gas from diffusing into the transfer chamber. As a method of preventing the diffusion of the halogen-containing gas in the processing chamber, a difference of a certain level or more is obtained so that the processing chamber is evacuated before the gate valve is opened after the processing so that the pressure in the transfer chamber is higher than the pressure in the processing chamber. It is conceivable to transport the substrate while maintaining the pressure.

  However, due to the limitations of the apparatus, the pressure difference between the processing chamber and the transfer chamber is naturally limited, and even if the maximum allowable pressure difference between them is secured, the temperature between the processing chamber and the transfer chamber still remains. A processing gas in the processing chamber may diffuse into the transfer chamber due to a difference or the like. For example, when a process involving heat treatment is performed in the processing chamber, the processing chamber becomes high temperature, and the halogen-containing gas in the processing chamber diffuses from the high-temperature processing chamber to the low-temperature transfer chamber.

Japanese Patent Application Laid-Open No. 7-94488.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a processing method and a processing system that can effectively prevent diffusion of residual gas in a processing chamber.

In order to solve the above problems, according to a first aspect of the present invention, a processing chamber for performing a predetermined gas processing on a substrate to be processed under vacuum, an exhaust device for evacuating the processing chamber, and an opening / closing device in the processing chamber The substrate to be processed is processed in the processing chamber using a processing system including a vacuum preparatory chamber that is connected via a vacuum, and is then opened in the processing chamber. A processing method for transporting to a preliminary chamber, wherein the exhaust chamber exhausts the processing chamber immediately before opening the opening / closing device, and the pressure of the processing chamber is made smaller than the pressure of the vacuum preliminary chamber, Provided is a processing method characterized in that an inert gas is supplied into the processing chamber while continuing the evacuation when a differential pressure between the processing chamber and the vacuum preparatory chamber becomes a certain level or more. .

In a second aspect of the present invention, a processing chamber for performing a predetermined gas process on a substrate to be processed under vacuum, an exhaust device for evacuating the processing chamber, and a vacuum chamber connected to the processing chamber via an opening / closing device. A preliminary vacuum chamber held below, a gas supply system for supplying a processing gas and an inert gas to the processing chamber, and a control means for controlling the exhaust device, the switchgear and the gas supply system, After processing the substrate to be processed in the processing chamber, the processing system is configured to open the switching device and transport the processing substrate to the vacuum preparatory chamber, and the control means immediately before opening the switching device, When the processing chamber is evacuated by an exhaust device, the pressure of the processing chamber is made smaller than the pressure of the vacuum preparatory chamber, and when the differential pressure between the processing chamber and the vacuum preparatory chamber becomes a certain level or more , While continuing the evacuation, Provided is a processing system that controls the exhaust device, the opening / closing device, and the gas supply system so as to supply an inert gas into a processing chamber.

  In the first aspect and the second aspect, after processing the substrate to be processed in the processing chamber, immediately before opening the opening / closing device, the processing chamber is evacuated by the exhaust device, and the inert gas is introduced into the processing chamber. By supplying, a flow of an inert gas in the exhaust direction is formed in the processing chamber, and this inert gas flow prevents diffusion of the residual gas in the processing chamber, so that the residual gas in the processing chamber is opened when the switchgear is opened. Can be effectively prevented from diffusing into the vacuum prechamber.

  In the first and second aspects, it is preferable that the switchgear is opened in a state where the pressure in the vacuum preliminary chamber is higher than the pressure in the processing chamber. Thereby, the diffusion of the residual gas in the processing chamber can be prevented more effectively. Note that the larger the differential pressure between the processing chamber and the vacuum preparatory chamber, the more effective is the prevention of residual gas diffusion. However, according to the present invention, it is difficult to diffuse the residual gas by the inert gas flow. Therefore, even if the pressure difference is smaller than the conventional pressure, the residual gas can be effectively prevented from diffusing, which is advantageous when it is difficult to secure the pressure difference. Specifically, the differential pressure can be set as small as 15 Pa or less.

  According to the present invention, after processing a substrate to be processed in the processing chamber, immediately before opening the opening / closing device, an inert gas is supplied into the processing chamber while evacuating the processing chamber with the exhaust device. By forming the flow of the inert gas in the exhaust direction, it is possible to prevent the residual gas from diffusing in the processing chamber and effectively prevent the residual gas from diffusing into the vacuum preparatory chamber when the switchgear is opened. Therefore, contamination and corrosion in the vacuum preparatory chamber can be prevented.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing a multi-chamber type film forming system which is an embodiment of the processing system of the present invention.

  As shown in FIG. 1, this film forming system 100 includes two Ti film forming apparatuses 1 and 2 for forming a Ti film on a wafer W as a substrate to be processed by plasma CVD under vacuum, and a Ti film by thermal CVD. There are a total of four film forming apparatuses, ie, two TiN film forming apparatuses 3 and 4 for forming a TiN film on the TiN film forming apparatus. It is provided corresponding to each of the four sides of the rectangular wafer transfer chamber 5. Load lock chambers 6 and 7 are provided on the other two sides of the wafer transfer chamber 5, respectively. A wafer loading / unloading chamber 8 is provided on the opposite side of the load lock chambers 6 and 7 to the wafer transfer chamber 5, and a wafer W can be accommodated on the opposite side of the load locking chambers 6 and 7 of the wafer loading / unloading chamber 8. Ports 9, 10, and 11 for attaching three FOUPs F are provided.

  The Ti film forming apparatuses 1 and 2 each have a Ti film forming chamber 31 for forming a Ti film under a vacuum, and the TiN film forming apparatuses 3 and 4 each form a TiN film for forming a TiN film under a vacuum. The Ti film forming chamber 31, the TiN film forming chamber 131, and the load lock chambers 6 and 7 are connected to each side of the wafer transfer chamber 5 through a gate valve G as shown in FIG. These are communicated with the wafer transfer chamber 5 by opening each gate valve G, and are disconnected from the wafer transfer chamber 5 by closing each gate valve G. A gate valve G is also provided at a portion of the load lock chambers 6 and 7 connected to the wafer loading / unloading chamber 8. The load lock chambers 6 and 7 open the gate loading / unloading chamber 8 by opening the gate valve G. 8, and is closed from the wafer loading / unloading chamber 8 by closing them.

  In the wafer transfer chamber 5, a wafer transfer apparatus for carrying in and out the wafer W as a substrate to be processed with respect to the Ti film forming apparatuses 1 and 2, the TiN film forming apparatuses 3 and 4, and the load lock chambers 6 and 7. 12 is provided. The wafer transfer device 12 is disposed substantially at the center of the wafer transfer chamber 5 and has two blades 14 a and 14 b that hold the wafer W at the tip of a rotatable / extensible / retractable portion 13 that can be rotated and extended. These two blades 14a and 14b are attached to the rotating / extending / contracting portion 13 so as to face opposite directions. The two blades 14a and 14b can be expanded and contracted individually or simultaneously. The inside of the wafer transfer chamber 5 is maintained at a predetermined degree of vacuum by an exhaust device (not shown). In this embodiment, the wafer transfer chamber pressure is maintained at 53 Pa.

  A HEPA filter (not shown) is provided in the ceiling portion of the wafer carry-in / out chamber 8, and clean air that has passed through the HEPA filter is supplied into the wafer carry-in / out chamber 8 in a down-flow state. The wafer W is loaded and unloaded in a clean air atmosphere. Shutters (not shown) are provided in the three ports 9, 10, 11 for attaching the FOUP F of the wafer carry-in / out chamber 8, and the wafers W are accommodated in these ports 9, 10, 11 or empty. The hoop is directly attached, and when it is attached, the shutter is released to communicate with the wafer carry-in / out chamber 8 while preventing the entry of outside air. An alignment chamber 15 is provided on the side surface of the wafer carry-in / out chamber 8 where the wafer W is aligned.

  In the wafer loading / unloading chamber 8, a wafer transfer device 16 for loading / unloading the wafer W into / from the FOUP F and loading / unloading the wafer W into / from the load lock chambers 6, 7 is provided. The wafer transfer device 16 has an articulated arm structure and can run on the rail 18 along the direction in which the hoops F are arranged, and the wafer W is placed on the hand 17 at the tip thereof and transferred. I do.

  The processing system controller 19 controls the entire system such as opening / closing operations of the gate valves G and operations of the wafer transfer apparatuses 12 and 16.

  Next, the Ti film forming apparatus 1 will be described. As described above, the Ti film forming apparatus 2 also has the same configuration. FIG. 2 is a cross-sectional view showing a Ti film forming apparatus for performing the plasma CVD film forming method. The Ti film forming apparatus 1 has the Ti film forming chamber 31 as described above. The Ti film forming chamber 31 is a substantially cylindrical chamber that is hermetically configured, and a cylinder in which a susceptor 32 for horizontally supporting a wafer W, which is a substrate to be processed, is provided at the center lower portion. It arrange | positions in the state supported by the support member 33 of a shape.

  The susceptor 32 is made of ceramics such as AlN, and has a countersink portion 32a for accommodating the wafer W on the surface thereof. The wafer W is guided by a tapered portion formed at the peripheral edge thereof. Are positioned with respect to each other. A heater 35 is embedded in the susceptor 32, and the heater 35 is heated by the heater power supply 36 to heat the wafer W to a predetermined temperature. An electrode 38 functioning as a lower electrode is embedded in the susceptor 32 on the heater 35.

  A shower head 40 is provided on the top wall 31 a of the chamber 31 via an insulating member 39. The shower head 40 includes an upper block body 40a, a middle block body 40b, and a lower block body 40c. A ring-shaped heater 76 is embedded in the vicinity of the outer periphery of the lower block body 40c. The heater 76 is supplied with power from a heater power supply 77, so that the shower head 40 can be heated to a predetermined temperature. ing.

  Discharge holes 47 and 48 for discharging gas are alternately formed in the lower block body 40c. A first gas supply port 41 and a second gas supply port 42 are formed on the upper surface of the upper block body 40a. In the upper block body 40 a, a large number of gas passages 43 are branched from the first gas supply port 41. Gas passages 45 are formed in the middle block body 40b, and the gas passages 43 communicate with the gas passages 45 through a plurality of grooves 43a through which gas is supplied and diffused. Further, the gas passage 45 communicates with the discharge hole 47 of the lower block body 40c. In the upper block body 40a, a large number of gas passages 44 are branched from the second gas supply port. Gas passages 46 are formed in the middle block body 40 b, and the gas passages 44 communicate with these gas passages 46. A plurality of grooves 46a are formed on the lower surface of the middle block body 40b. The grooves 46a are connected to the gas passage 46 and diffuse gas supplied from the gas passage 46. A plurality of discharge holes of the groove 46a and the lower block body 40c are formed. 48 communicates. The first and second gas supply ports 41 and 42 are respectively connected to gas lines 58 and 60 of a gas supply mechanism 50 described later.

Gas supply mechanism 50, ClF ₃ gas (halogen-containing gas) TiCl ₄ gas supply source 52 for supplying TiCl ₄ gas (halogen-containing gas) is a ClF ₃ gas supply source 51, Ti-containing gas supplied to a cleaning gas , plasma gas and is Ar gas Ar gas supply source 53 for supplying a reducing gas at a _{H 2} gas to supply _{H 2} gas supply source 54, an NH ₃ gas and supplying NH ₃ gas supply source 55 is a gas nitriding, and a N ₂ gas supply source 56 for supplying N ₂ gas is an inert gas. The ClF ₃ gas supply source 51 includes a ClF ₃ gas supply line 57, the TiCl ₄ gas supply source 52 includes a TiCl ₄ gas supply line 58, the Ar gas supply source 53 includes an Ar gas supply line 59, and H _{2 H 2} gas line 60 to a gas supply source 54 is, NH ₃ gas supply line 60a to the NH ₃ gas supply source 55, the _{N 2} gas supply source 56 _{N 2} gas supply line 60b are connected, respectively . Each gas supply line is provided with two on-off valves 61 sandwiching the mass flow controller 62 and the mass flow controller 62.

A TiCl ₄ gas supply line 58 extending from a TiCl ₄ gas supply source 52 is connected to the first gas supply port 41, and a ClF ₃ gas extending from a ClF ₃ gas supply source 51 is connected to the TiCl ₄ gas supply line 58. An Ar gas supply line 59 extending from the supply line 57 and the Ar gas supply source 53 is connected. Further, an H ₂ gas supply line 60 extending from an H ₂ gas supply source 54 is connected to the second gas supply port 42, and this H ₂ gas supply line 60 extends from an NH ₃ gas supply source 55. An NH ₃ gas supply line 60 a and an N ₂ gas supply line 60 b extending from the N ₂ gas supply source 56 are connected. Therefore, at the time of film formation, TiCl ₄ gas is supplied from the TiCl ₄ gas supply source 52, Ar gas is supplied from the Ar gas supply source 53 to the TiCl ₄ gas supply line 58, and the first gas supply port 41 passes through the shower head 40. To be supplied. Then, the gas is discharged from the discharge hole 47 into the chamber 31 through the gas passages 43 and 45. On the other hand, H ₂ gas, which is a reducing gas, is supplied from the H ₂ gas supply source 54 to the H ₂ gas supply gas line 60 and is supplied into the shower head 40 through the gas supply port 42, and the gas passages 44, 46. Then, the ink is discharged from the discharge hole 48 into the chamber 31. That is, the shower head 40 is a post-mix type in which TiCl ₄ gas and H ₂ gas are supplied into the chamber 31 completely independently, and these are mixed in the chamber 31 after discharge to cause a reaction. When nitriding is performed after the Ti film is formed, NH ₃ gas from the NH ₃ gas supply source 55, H ₂ gas as a reducing gas, and Ar gas as a plasma gas are discharged through the shower head 40. The gas is discharged from the outlet 48 into the chamber 31, and the plasma is purified to nitride the Ti film. Further, the valve 61 and the mass flow controller 62 are controlled by a film forming apparatus controller 78.

  A transmission path 63 is connected to the shower head 40, and a high frequency power supply 64 is connected to the transmission path 63 via a matching unit 80, and the transmission path 63 is connected from the high frequency power supply 64 during film formation. The high-frequency power is supplied to the shower head 40. By supplying high-frequency power from the high-frequency power supply 64, a high-frequency electric field is generated between the shower head 40 and the electrode 38, and the gas supplied into the chamber 31 is turned into plasma to form a Ti film. As the high frequency power supply 64, one having a frequency of 400 kHz to 60 MHz, preferably 450 kHz is used.

  A circular hole 65 is formed at the center of the bottom wall 31 b of the chamber 31, and an exhaust chamber 66 protruding downward is provided on the bottom wall 31 b so as to cover the hole 65. An exhaust pipe 67 is connected to the side surface of the exhaust chamber 66, and an exhaust device 68 is connected to the exhaust pipe 67. The exhaust device 68 is controlled by a film forming device controller 78 based on a command from the processing system controller 19. By operating the exhaust device 68, the chamber 31 is exhausted through the exhaust chamber 66, and the inside of the chamber 31 can be decompressed to a predetermined degree of vacuum. In this case, since the exhaust flow from the chamber 31 is once guided to the exhaust chamber 66, the inside of the chamber 31 is uniformly exhausted, and the inside of the chamber 31 becomes a uniform reduced pressure atmosphere.

  The susceptor 32 is provided with three wafer support pins 69 (only two are shown) for supporting the wafer W to be moved up and down so as to protrude and retract with respect to the surface of the susceptor 32. It is fixed to the plate 70. The wafer support pins 69 are moved up and down via a support plate 70 by a drive mechanism 71 such as an air cylinder.

  On the side wall of the chamber 31, a loading / unloading port 72 for loading / unloading the wafer W to / from the wafer transfer chamber 5 and a gate valve G for opening / closing the loading / unloading port 72 are provided. The opening / closing operation of the gate valve G is controlled by the film forming apparatus controller 78 based on a command from the processing system controller 19.

Next, a processing method for forming a Ti film on the wafer W by using the film forming system 100 will be described with reference to the flowchart of FIG.
First, one wafer W is taken out from any one of the FOUPs F by the wafer transfer device 16 in the wafer loading / unloading chamber 8 and loaded into the alignment chamber 15 to align the wafer W. Next, the wafer W is carried into one of the load lock chambers 6 and 7, and the inside of the load lock is evacuated. On the other hand, in the Ti film forming apparatus 1, before the wafer W is carried in, the chamber 31 is brought into a predetermined vacuum state by the exhaust device 68.

  In this state, after the wafer W in the load lock is taken out by the blade 14a or 14b of the transfer device 12 in the wafer transfer chamber 5, the gate valve G is opened in a vacuum state higher than that of the Ti film forming device 1, and the wafer is released. W is carried into the chamber 31 of the Ti film forming apparatus 1 from the wafer transfer chamber 5, and the wafer W is placed on the susceptor 32 (STEP 1).

Next, while the wafer W is heated by the heater 35 and Ar gas and H ₂ gas are respectively supplied into the chamber 31 at a predetermined flow rate and preflow is performed, TiCl ₄ gas is supplied into the chamber 31 while maintaining these flow rates. To supply. Then, a high frequency power is supplied from the high frequency power supply 64 to the shower head 40 to form a Ti film by plasma CVD (STEP 2). In the present embodiment, the pressure in the chamber 31 during film formation is set to 667 Pa, and the high-frequency power is set to 800 W. The flow rates of Ar gas, H ₂ gas, and TiCl ₄ gas are set to 1.6 L / min, 4.0 L / min, and 0.012 L / min, respectively, for example.

  The film formation time can be appropriately set according to the desired film thickness. For example, when a Ti film having a thickness of 10 nm is formed, it is performed for 30 seconds. At this time, the heating temperature (susceptor temperature) of the wafer W by the heater 35 is about 500 to 700 ° C.

After the film formation, the supply of TiCl ₄ gas and the power supply from the high frequency power supply 64 are stopped, the flow rate of H ₂ gas is reduced to, for example, 2.0 L / min, the Ar gas flow rate is maintained, and the purge in the chamber is performed. Do.

Thereafter, nitriding treatment is performed on the surface of the formed Ti film (STEP 3). In the nitriding process, NH ₃ gas is allowed to flow at a flow rate of, for example, 1.5 L / min for about 10 seconds while maintaining the flow rates of Ar gas and H ₂ gas, and then, for example, 800 W from the high frequency power supply 64 while maintaining the supply of gas. The high frequency power is supplied to form plasma. This nitriding treatment is performed, for example, for 30 seconds.

  After completion of the nitriding process, the power supply from the high frequency power supply is stopped and the flow rate of each gas is gradually reduced (STEP 4), and the inside of the chamber 31 is evacuated by the exhaust device 68 (STEP 5). By gradually reducing the gas flow rate and evacuating the inside of the chamber 31 in this way, the pressure in the chamber 31 maintained at 667 Pa is reduced, and the inside of the wafer transfer chamber 5 held at 53 Pa as described above. It becomes smaller than the pressure.

In this way, when the pressure difference between the chamber 31 and the wafer transfer chamber 5 becomes a certain level or more, an inert gas, for example, N ₂ gas is supplied from the N ₂ gas supply source 56 while evacuation is continued. The liquid is supplied into the chamber 31 through the shower head 40 (STEP 6). By supplying this N ₂ gas, the pressure in the chamber 31 gradually increases, but after a predetermined time has elapsed from the start of N ₂ gas supply, the pressure in the chamber 31 is lower than the pressure in the wafer transfer chamber 5, That is, the gate valve G is opened in a state where a differential pressure is generated between the chamber 31 and the wafer transfer chamber 5 (STEP 7). In this case, the time from the start of the supply of the inert gas to the opening of the gate valve G is preferably at least 1 second, and more preferably 1 to 5 seconds in view of the processing speed. Subsequently, the blade 14a or 14b of the transfer device 12 is inserted into the chamber 31, and the wafer W is transferred to the wafer transfer chamber 5 (STEP 8).

In the present embodiment, just before the gate valve G is opened, N ₂ gas is supplied into the chamber 31 while the chamber 31 is evacuated, so that a shower is provided in the chamber 31 as shown in FIG. A gas flow R from the head 40 toward the exhaust chamber 66 is formed, and even if the gate valve G is opened in this state, ClF ₃ gas and TiCl ₄ gas remaining in the chamber 31 and a halogen-containing gas such as a by-product gas Is prevented from diffusing into the wafer transfer chamber 5. When only vacuuming is performed without supplying an inert gas, and the differential pressure between the chamber 31 and the wafer transfer chamber 5 is simply increased, the halogen-containing gas is caused by a temperature difference or the like in the wafer transfer chamber. However, in the present embodiment, the vacuum transfer is performed and the gas flow R that can prevent the halogen-containing gas from flowing out is formed in the present embodiment. It is possible to prevent the halogen-containing gas from diffusing to the surface very effectively. In order to prevent the halogen-containing gas from diffusing due to the gas flow R in this way, the differential pressure between the chamber 31 and the wafer transfer chamber 5 is not essential, and 15 Pa or less is sufficient. Therefore, this is particularly effective in an apparatus having a configuration in which it is difficult to ensure a sufficient differential pressure.

From the viewpoint of more effectively preventing gas diffusion, it is preferable to open the gate valve G and transfer the wafer W to the wafer transfer chamber 5 while continuing to supply the N ₂ gas into the chamber 31.

  The wafer W transferred into the wafer transfer chamber 5 is then transferred to the TiN film forming chamber 131 of any of the TiN apparatuses 3 and 4 for TiN film forming processing as necessary, or transferred. After the wafer 12 is loaded into one of the load lock chambers 6 and 7 by the apparatus 12 and the inside thereof is returned to atmospheric pressure, the wafer W in the load lock chamber 16 is taken out by the wafer transfer device 16 in the wafer carry-in / out chamber 8. Contained in either.

Next, the result of actually confirming the effect of the present invention will be described. FIG. 5 shows a case in which N ₂ gas is supplied into the chamber 31 while the chamber 31 is evacuated according to the present invention (invention example) and a case where only the evacuation is performed (comparative example 1) before and after the gate valve is opened. It is a graph which shows the change of the pressure in a chamber. In the example of the present invention, while the evacuation in the chamber 31 is continued, as shown in FIG. 5, when the pressure difference with the wafer transfer chamber 5 becomes about 35 Pa, the flow rate is 0.24 L / min in the chamber 31. Then, N ₂ gas was supplied, and after 5 seconds from the supply of N ₂ gas, the gate valve G was opened while the differential pressure between the chamber 31 and the wafer transfer chamber 5 was 10 Pa. On the other hand, in Comparative Example 1, only the evacuation was performed, and the gate valve G was opened while the differential pressure between the chamber 31 and the wafer transfer chamber 5 was 38 Pa. Regarding these inventive examples and comparative example 1, the diffusion amount of Cl (chlorine) from the chamber 31 after the gate valve G was opened to the wafer transfer chamber 5 was determined. Similarly, when the gate valve was opened at the time when the pressure difference between the chamber 31 and the wafer transfer chamber 5 was 10 Pa by performing only vacuuming, the diffusion amount of Cl was similarly grasped (Comparative Example 2). . The amount of diffusion of Cl was obtained by detecting the Cl concentration in the wafer transfer chamber before and after opening the gate valve and calculating the difference in concentration. These results are shown in Table 1.

As shown in Table 1, the Cl diffusion amount of Comparative Example 1 in which only vacuuming was performed and the differential pressure was 38 Pa was 1.0 × 10 ¹³ , whereas in the present invention example, the differential pressure was 10 Pa. Nevertheless, the Cl diffusion amount was 2.7 × 10 ¹² (atoms / cm ² ), which was lower than that of Comparative Example 1. In Comparative Example 2 in which only the evacuation was performed with the differential pressure of 10 Pa as in the case of the present invention, the Cl diffusion amount was 1.4 × 10 ¹⁶ (atoms / cm ² ), which was extremely large. Thereby, it was confirmed that by introducing N ₂ gas, diffusion of the residual gas in the chamber can be effectively prevented even if the differential pressure is small.

  The present invention can be variously modified without being limited to the above embodiment. For example, in the above embodiment, the case where the wafer W is transferred from the chamber 31 of the Ti film forming apparatus 1 to the wafer transfer chamber 5 after Ti film forming by the Ti film forming apparatus 1 has been described. The present invention is not limited to this, and the present invention can also be applied to the case where the TiN film forming apparatus 3 or 4 is used to transfer the TiN film to the wafer transfer chamber 5 from the chamber 131 of the TiN film forming apparatus. In the above embodiment, a multi-chamber type film forming system including a plurality of processing apparatuses is used. However, the present invention relates to a single processing chamber and a vacuum reserve connected to the processing chamber and held under vacuum. And a single chamber type film forming system including a chamber. Furthermore, the present invention is not limited to a film forming system that performs Ti film formation or TiN film formation, and can be applied to any processing system that processes a semiconductor substrate with a corrosive gas or a reactive gas, such as dry etching or plasma CVD film formation. . The substrate to be processed is not limited to a semiconductor wafer, and may be another substrate such as a liquid crystal display (LCD) substrate.

1 is a schematic configuration diagram showing a multi-chamber type film forming system for carrying out the method of the present invention. 2 is a cross-sectional view showing a Ti film forming apparatus of the film forming system 1. FIG. The flowchart for demonstrating an example of the process at the time of forming Ti film | membrane. Diagram schematically illustrating the N ₂ gas flow formed into Ti deposition chamber. The graph which shows the change of the Ti film forming chamber internal pressure before and behind gate valve opening.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Ti film-forming apparatus 3,4 TiN film-forming apparatus 5 Wafer transfer chamber 31 Ti film-forming chamber 32 Susceptor 35 Heater 40 Shower head 50 Gas supply mechanism 64 High frequency power supply 68 Exhaust device G Gate valve W Semiconductor wafer

Claims (6)

A processing chamber for performing predetermined gas processing on the substrate to be processed under vacuum; an exhaust device for evacuating the processing chamber; a vacuum preliminary chamber connected to the processing chamber via an opening / closing device and held under vacuum; A processing system comprising: processing a substrate to be processed in the processing chamber, and then opening the opening and closing device to transfer the substrate to be processed to the vacuum preliminary chamber,
Immediately before opening the opening / closing device, the processing chamber is evacuated by the exhaust device , the pressure of the processing chamber is made smaller than the pressure of the vacuum preparatory chamber, and the space between the processing chamber and the vacuum preparatory chamber is reduced. A processing method comprising supplying an inert gas into the processing chamber while continuing the evacuation when the differential pressure becomes a certain level or more .   The processing method according to claim 1, wherein the switchgear is opened in a state where the pressure in the vacuum preliminary chamber is higher than the pressure in the processing chamber.   The processing method according to claim 2, wherein a differential pressure between the processing chamber and the preliminary vacuum chamber is 15 Pa or less. A processing chamber for performing predetermined gas processing on the substrate to be processed under vacuum; an exhaust device for evacuating the processing chamber; a vacuum preliminary chamber connected to the processing chamber via an opening / closing device and held under vacuum; A gas supply system for supplying a processing gas and an inert gas to the processing chamber, and a control means for controlling the exhaust device, the switchgear, and the gas supply system, and processing a substrate to be processed in the processing chamber. Thereafter, the opening and closing device is opened and the substrate to be processed is transferred to the vacuum preliminary chamber,
The control means evacuates the processing chamber by the exhaust device immediately before opening the opening / closing device, and makes the pressure in the processing chamber smaller than the pressure in the vacuum preparatory chamber. The exhaust device, the opening / closing device, and the gas supply system are arranged so as to supply an inert gas into the processing chamber while continuing the evacuation when a differential pressure between the chamber and the chamber becomes a certain level or more. A processing system characterized by controlling.   The control means controls the exhaust device and the switchgear so as to open the switchgear in a state where the pressure in the vacuum preparatory chamber is higher than the pressure in the processing chamber. The processing system described in. The processing system according to claim 5, wherein a differential pressure between the processing chamber and the vacuum preliminary chamber is 15 Pa or less.

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