Film forming apparatus, film forming method, and substrate supporting member

Abstract

The invention provides a film forming apparatus, a film forming method, and a substrate supporting member. The purpose of the present invention is to prevent the occurrence of defects in the subsequent processing of a substrate due to film residues after processing when film formation processing is performed on a substrate. The film forming apparatus includes: a processing container; a first gas supply unit that supplies a film formation gas into the processing container in order to form a film on the substrate placed on the stage; a second gas supply unit that supplies a cleaning gas that removes a film formed in the processing container by the film-forming gas in a state in which the substrate is not accommodated in the processing container; a through hole formed in the stage in the longitudinal direction; a rod-shaped substrate support member which is provided in the through-hole in order to support the substrate and which extends in the longitudinal direction; a height changing mechanism that changes the relative height between the stage and the substrate support member so as to switch between a state in which the substrate is supported by the stage and a state in which the substrate is supported by the substrate support member; and a groove which is formed on a side surface of the substrate support member and forms a flow path for the cleaning gas.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a film forming apparatus, a film forming method, and a substrate support member. BACKGROUND

[0002] In manufacturing a semiconductor device, various films are formed by supplying a gas to a substrate such as a semiconductor wafer (hereinafter, referred to as a wafer) placed on a stage in a processing container set to a vacuum pressure. As for an apparatus that performs the film formation, there is a case where a substrate support member for supporting a substrate so as to raise and lower the substrate is provided to an upper surface of the stage in order to hand over the substrate between the stage and a conveyance mechanism that conveys the substrate in and out of the processing container.

[0003] In Patent Literature 1, a lift pin as the above-described substrate support member is shown to have a structure where a lower end portion is partially removed to have an enlarged diameter. It is provided that, by performing exhaust on the inside of the processing container, gas accumulated between the substrate and the upper surface of the stage is removed by passing through the removed portion of the lift pin and flowing through a through-hole of the stage, which the lift pin penetrates, to prevent the substrate from slipping on the stage.

[0004] Prior art documents

[0005] Patent documents

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2023-165658 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The present disclosure provides the following technology: in film formation processing of a substrate, it is possible to prevent a processing defect of a subsequent substrate due to a film residue after processing.

[0009] SOLUTION TO PROBLEM

[0010] The film formation apparatus of the present disclosure includes a processing container having a stage for placing a substrate inside, the inside of which is exhausted; a first gas supply portion for supplying a film formation gas into the processing container for film formation on the substrate placed on the stage; a second gas supply portion for supplying a cleaning gas for removing a film formed by the film formation gas in the processing container in a state where the substrate is not housed in the processing container; a through-hole formed in the stage along a longitudinal direction; a substrate support member provided in the through-hole for supporting the substrate and extending in the longitudinal direction; a height changing mechanism for changing a relative height between the stage and the substrate support member to switch between a state where the substrate is supported by the stage and a state where the substrate is supported by the substrate support member; and a groove formed in a side surface of the substrate support member and constituting a flow path of the cleaning gas.

[0011] Effects of the Invention

[0012] The present disclosure can prevent a processing of a subsequent substrate from being adversely affected by a film residue after processing. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a longitudinal sectional side view of a film formation apparatus according to an embodiment of the present disclosure.

[0014] Figure 2 FIG. 2 is a plan view of a stage in the film formation apparatus.

[0015] Figure 3 FIG. 3 is a perspective view of a lift pin provided in the stage.

[0016] Figure 4 FIG. 4 is a transverse sectional plan view of the lift pin.

[0017] Figure 5 FIG. 5 is a schematic view showing a flow of a gas during a cleaning process in the film formation apparatus.

[0018] Figure 6 FIG. 6 is a process diagram showing an operation of the lift pin in the film formation apparatus.

[0019] Figure 7 FIG. 7 is a schematic view showing a flow of a gas during a cleaning process in the film formation apparatus.

[0020] Figure 8 FIG. 8 is a process diagram showing an operation of a lift pin in a comparative example.

[0021] Figure 9 FIG. 9 is a schematic view showing a flow of a gas around the lift pin.

[0022] Figure 10is a side view showing another structure example of the lift pin.

[0023] Figure 11 is a longitudinal sectional side view of a film formation apparatus 1 provided with a lift pin of another structure.

[0024] Figure 12 is a diagram showing the result of an evaluation test.

[0025] Figure 13 is a diagram showing the result of a comparison test.

[0026] Explanation of Reference Numerals

[0027] W, wafer; 11, processing container; 21, stage; 28, 35, lift mechanism; 44, cleaning gas supply part; 57, gas supply part; 6, lift pin; 63, groove. DETAILED DESCRIPTION

[0028] Reference Figure 1 A film formation apparatus 1 of an embodiment of the present disclosure is described with reference to a longitudinal sectional side view. The film formation apparatus 1 is provided with a processing container 11 that is evacuated to be a vacuum pressure, and a wafer W is subjected to film formation by being housed in the processing container 11 and being supplied with a film formation gas. In this example, film formation of a TiN (Titanium Nitride) film is performed by ALD. After a plurality of wafers W are subjected to film formation processing by repeating the film formation processing a predetermined number of times, for example, a cleaning processing of supplying a cleaning gas into the processing container 11 is performed in a state where the wafer W is not housed in the processing container 11. Thereby, the TiN film formed in each part of the processing container 11 at the time of film formation of the wafer W is removed.

[0029] The processing container 11 is formed in a circular shape in plan view. A wafer W is provided with a loading / unloading port 12 and a gate valve 13 that opens and closes the loading / unloading port 12 on the side wall of the processing container 11. An exhaust duct 14 that is square in longitudinal section and is formed in a circular ring shape in plan view is provided at a position on the upper side than the loading / unloading port 12, and the exhaust duct 14 forms a part of the processing container 11. An exhaust port 15 is opened on the side wall on the inner periphery side of the exhaust duct 14 along the circumferential direction of the exhaust duct 14. Thus, the exhaust port 15 is formed on the side wall of the processing container 11, and in plan view, the exhaust port 15 is formed in a circular ring shape so as to surround a stage 21 that will be described later.

[0030] An exhaust mechanism 16 is connected to the exhaust pipe 14. The exhaust mechanism 16 includes a valve sandwiched in an exhaust path, a vacuum pump that exhausts the inside of the processing container 11 via the exhaust path, and a control section 100 that adjusts the opening degree of the valve to adjust the exhaust amount from the exhaust port 15 to form a desired pressure of a vacuum atmosphere in the processing container 11. In addition, in the drawing, a reference numeral 14A is a flow restriction member that is provided on the inner peripheral side of the exhaust pipe to restrict the flow of gas at the time of film formation processing.

[0031] Also referring to Figure 2 A top view of a stage 21 provided in the processing container 11 will be described. As illustrated, the stage 21 is circular in plan view. A part of the upper side of the stage 21 is recessed to form a circular recess 22. The recess 22 is three, and is provided at the peripheral portion of the stage 21 to be arranged at intervals from each other along the circumferential direction of the stage 21.

[0032] A bottom surface of each of the recesses 22 forms a pin support surface 23 that supports a lift pin 6 to be described later, and is formed as a horizontal surface. Also, a part of the upper surface of the stage 21 that is located outside the recess 22 is provided as a wafer support surface 24. The wafer support surface 24 is also formed as a horizontal surface, and a wafer W is horizontally placed on the wafer support surface 24. As above, the pin support surface 23 and the wafer support surface 24 each form a part of the upper surface of the stage 21. In addition, the wafer support surface 24 occupies a large part of the upper surface of the stage 21.

[0033] As illustrated in Figure 1 , the stage 21 is formed with a through-hole 25 that extends in the longitudinal direction, more specifically, in the vertical direction, and the upper end and the lower end of the through-hole 25 are respectively open at the pin support surface 23 and the lower surface of the stage 21. In addition, the through-hole 25 is provided for each of the recesses 22. Thus, only two through-holes 25 are illustrated in Figure 1 , but a total of three are provided. In plan view, the through-holes 25 are circular. Also, in plan view, the diameter of the through-hole 25 is smaller than the diameter of the recess 22, and the center of the recess 22 and the center of the through-hole 25 are aligned with each other. Thus, it can also be said that the recess 22 is formed by expanding the diameter of the upper side of the through-hole formed in the stage 21. The lift pin 6 is provided in the through-hole 25, but the lift pin 6 will be described in detail later. In addition, the peripheral surface of the through-hole 25 is denoted as a hole wall surface 20.

[0034] A heater 26 is embedded in the stage 21, and heating is performed to bring the wafer W placed on the aforementioned wafer supporting surface 24 to a predetermined temperature. The central lower portion of the stage 21 is supported by the upper end of a support column 27, and the lower end side of the support column 27 penetrates the bottom of the processing container 11 and is connected to a lifting mechanism 28 provided on the outside of the processing container 11. The stage 21 is lifted by the lifting mechanism 28 between a standby position on the lower side in the processing container 11 indicated by a broken line in Figure 1 , and a processing position on the upper side in the processing container 11 indicated by a solid line in Figure 1 .

[0035] The aforementioned standby position is a position where the wafer W is held in standby for handover between the conveying mechanism 10 and the wafer W that has entered the processing container 11 from the transfer-in / out port 12. The conveying mechanism 10 is not shown in Figure 1 , Figure 2 . The aforementioned processing position is a position where the wafer W is processed. Further, Figure 1 , the reference numeral 29 is a cover that surrounds the side of the stage 21, and is opposed to the flow restriction member 14A when the stage 21 is positioned at the processing position, and together with the flow restriction member 14A, restrains gas from being directed toward the lower surface of the stage 21.

[0036] In Figure 1 , the reference numeral 31 is a flange provided on the support column 27 and positioned below the bottom of the processing container 11. A bellows 32 that surrounds the support column 27 and is stretchable and contractible is provided. The bellows 32 is connected to the bottom of the processing container 11 and the flange 31 in a manner that ensures the airtightness of the processing container 11.

[0037] A support table 33 is provided on the lower side of the stage 21, and the aforementioned support column 27 penetrates the support table 33. The support table 33 is supported by the upper end of a support column 34, and the lower end of the support column 34 penetrates the bottom of the processing container 11 and is connected to a lifting mechanism 35 provided on the outside of the processing container 11. The support table 33 is lifted by the lifting mechanism 35, and in a state where the three lift pins 6 discussed later are supported by the support table 33, these lift pins 6 are lifted together. A bellows 36 that surrounds the aforementioned support column 34 and is stretchable and contractible is provided. The bellows 36 is connected to the bottom of the processing container 11 and the lifting mechanism 35 in a manner that ensures the airtightness of the processing container 11.

[0038] Gas supply ports 41, 42 are opened in the bottom of the processing container 11. A non-active gas supply mechanism 43 and a cleaning gas supply mechanism 44 are connected to the gas supply ports 41, 42, respectively, by gas supply pipes. The cleaning gas supply mechanism corresponds to the second gas supply portion. Non-active gas and cleaning gas are supplied from the non-active gas supply mechanism 43 and the cleaning gas supply mechanism 44 into the processing container 11 via the gas supply ports 41, 42, respectively.

[0039] The non-reactive gas is specifically, for example, N2 gas, and is supplied during the cleaning process and during the film formation process in order to adjust the partial pressure of the cleaning gas within the processing container 11 during the cleaning process, or to prevent the inflow of the film formation gas to the lower side of the stage 21 during the film formation process. The cleaning gas described above is, for example, ClF3 gas, and is supplied from the gas supply port 42 at a predetermined stage of the cleaning process, as will be discussed later. Each of the gases supplied from the gas supply ports 41, 42 is removed by being discharged toward the upper side within the processing container 11 through the exhaust port 15 of the exhaust duct 14, and flows into the exhaust port 15.

[0040] A ceiling 51 is provided at the upper side of the exhaust duct 14 in such a manner as to block the processing container 11 from the upper side, and a shower head 52 in the shape of a circle in plan view is provided on the lower surface of the ceiling 51. The shower head 52 is provided with a gas diffusion space 53 provided within the shower head 52, and a plurality of discharge holes 54 are provided on the lower surface, each of the discharge holes 54 communicating with the gas diffusion space 53 and being formed opposite the stage 21. In addition, a ring-shaped protrusion 56 protruding downward is provided at the peripheral end portion of the shower head 52 in order to restrict the flow of gas.

[0041] When the stage 21 is located at the processing position, the ring-shaped protrusion 56 approaches the upper surface of the cover 29 of the stage 21, and the region surrounded by the stage 21, the ring-shaped protrusion 56, and the shower head 52 constitutes a processing space 50. The discharge holes 54 described above open to the processing space 50, and the gas is supplied to the wafer W located in the processing space 50 during the film formation process. When the stage 21 is thus located at the processing position, the exhaust port 15 described above is located to the side of the annular gap formed between the ring-shaped protrusion 56 and the cover 29, and the gas supplied to the processing space 50 flows to the side of the outside of the processing space 50, and flows into the exhaust port 15 to be removed.

[0042] A gas supply mechanism 57 is connected to the ceiling 51, and the gas supplied from the gas supply mechanism 57 is supplied to the gas diffusion space 53 through a flow path formed on the upper side of the ceiling 51 and the shower head 52, and is discharged from the discharge holes 54. The gas supplied from the gas supply mechanism 57 is a film formation gas, a non-reactive gas, and a cleaning gas. The film formation gas is a gas used for the film formation of the TiN film described above on the wafer W, and is, for example, TiCl4 gas and NH3 gas. The non-reactive gas is specifically, for example, N2 gas, and is supplied in order to purge the processing space 50 when performing ALD-based film formation, or to adjust the partial pressure of the cleaning gas within the processing container 11 during the cleaning process. The cleaning gas is specifically, for example, ClF3 gas, as with the gas supplied from the gas supply port 42.

[0043] The gas supply mechanism 57 described above corresponds to a first gas supply portion. The gas supply mechanism 57 and the gas supply mechanisms 43 and 44 described above each have a gas supply source that stores gas, a valve that is interposed in a flow path from the gas supply source to the processing container 11, a flow rate adjusting portion such as a mass flow controller that adjusts the flow rate of the gas supplied to the downstream side of the flow path, and the like.

[0044] Next, the lift pins 6 provided in the stage 21 will be described with reference to Figure 3 Figure 4 The lift pins 6 are substrate support members that transport the wafer W between the transport mechanism 10 and the stage 21, are provided for each through-hole 25, and are liftable with respect to the stage 21. In order to suppress thermal expansion, the lift pins 6 are composed of, for example, ceramic, more specifically, for example, alumina ceramic.

[0045] The lift pins 6 will be described in further detail. The lift pins 6 are round bar-shaped members that extend in the longitudinal direction, more specifically, in the vertical direction, and have a shaft portion 61 and a head portion 62 provided above the shaft portion 61. The shaft portion 61 and the head portion 62 each have a circular shape when viewed in the direction of extension of the lift pin 6 (i.e., the vertical direction), and the respective central axes coincide with each other. The head portion 62 has a larger diameter than the shaft portion 61 when viewed in the direction of extension of the lift pin 6, so as to be able to occlude the through-hole 25 at the time of film formation processing as will be discussed later. Thus, the head portion 62 has a larger area than the shaft portion 61 when viewed in the direction of extension.

[0046] The shaft portion 61 has a diameter that is slightly smaller than the diameter of the through-hole 25 of the stage 21, and the shaft portion 61 penetrates the through-hole 25 of the stage 21. The head portion 62 has a diameter that is slightly smaller than the diameter of the recess 22 of the stage 21. In a state in which the stage 21 is located at the processing position, the lower end of the lift pin 6 (the lower end of the shaft portion 61) is separated from the support table 33, the head portion 62 is accommodated in the recess 22, and is supported by the pin support surface 23 of the recess 22, thereby occluding the through-hole 25 from the upper side.

[0047] In a state in which the stage 21 is located at the standby position, as shown in Figure 5 ​As shown, the lower end of the lifting pin 6 contacts the support platform 33, and the head 62 of the lifting pin 6 protrudes from the recess 22 and is positioned above the wafer support surface 24. Because the lifting pin 6 contacts the support platform 33 in this way, the lifting pin 6 moves up and down simultaneously with the lifting of the support platform 33 by the lifting mechanism 35, changing its height relative to the stage 21. Furthermore, when the lifting pin 6 is supported by the support platform 33, its height relative to the stage 21 also changes due to the lifting of the stage 21 by the lifting mechanism 28. Therefore, the lifting mechanisms 28 and 35 constitute a height-changing mechanism that alters the relative height between the stage 21 and the lifting pin 6, switching between the state where the wafer W is supported by the wafer support surface 24 and the state where it is suspended relative to the wafer support surface 24 and supported by the lifting pin 6. Furthermore, Figure 5 The position of the lifting pin 6 is indicated when cleaning treatment is performed by supplying clean gas from the gas supply port 42, and the cleaning treatment is then described in detail.

[0048] A groove 63 is provided on the rod 61, extending from the upper end to the lower end along the extending direction of the rod 61. Four grooves 63 are provided, spaced apart when viewed along the extending direction, and are formed at equal intervals in the circumferential direction of the rod 61. In this example, as... Figure 4 As shown, the groove 63 is formed such that its side surface and bottom surface are orthogonal to each other. The rod portion 61 is provided in the through hole 25 as described above, therefore, the groove 63 is located opposite to the hole wall surface 20 of the through hole 25. As will be explained in detail later, each groove 63 forms a flow path for the cleaning gas when cleaning is performed by supplying cleaning gas from the gas supply port 42.

[0049] If returned Figure 1 To illustrate, the film-forming apparatus 1 includes a control unit 100, which functions as a computer. This control unit 100 contains a program. Commands (steps) are programmed into this program to execute the transfer of the wafer W to the transport mechanism 10, the film-forming process on the wafer W, and the cleaning process. This program is stored on a storage medium, such as an optical disc, hard disk, or DVD, and loaded into the control unit 100. The control unit 100 outputs control signals to each part of the film-forming apparatus 1 according to the program, controlling the operation of each part. Specifically, it controls the opening and closing of the gate valve 13, the raising and lowering of the stage 21 and support stage 33 by the lifting mechanisms 28 and 35, the supply of gases from the gas supply mechanisms 43, 44, and 57 to the processing container 11, the temperature of the heater 26, and the operation of the exhaust mechanism 16.

[0050] Next, refer to Figure 6 The process diagram showing the operation of the platform 21 and the lifting pin 6 and Figure 7 A schematic diagram of the film deposition apparatus 1 illustrates the feeding of wafer W relative to the film deposition apparatus 1 and the film deposition process performed on wafer W.Figure 7 The flow of the gas formed in the processing vessel 11 is indicated by arrows.

[0051] First, in a state where the stage 21 is located at the standby position and the upper portion side of the lift pin 6 including the head portion 62 protrudes upward from the recess 22 of the stage 21, the transport mechanism 10 supporting the wafer W enters the processing vessel 11 via the in-out port 12 and is located above the stage 21 (left end). The support table 33 is raised to push up the lift pin 6, and the wafer W is supported by the lift pin 6 instead of the transport mechanism 10 (second from the left). The transport mechanism 10 is withdrawn outside the processing vessel 11, the in-out port 12 is closed, and the stage 21 is raised. Further, as the stage 21 is raised, the head portion 62 of the lift pin 6 approaches the stage 21. Also, the stage 21 is temporarily stopped at a position where the wafer support surface 24 approaches the wafer W (set as a preheating position), and the wafer W is heated by the radiant heat from the stage 21 (center). Figure 6 Figure 6 Figure 6

[0052] Thereafter, the raising of the stage 21 is started again. By this, the wafer W is placed on the wafer support surface 24 and the temperature is further raised, while the head portion 62 of the lift pin 6 is housed in the recess 22 of the stage 21 (second from the right). Then, the stage 21 is further raised to support the lift pin 6 by the pin support surface 23 of the recess 22 instead of the support table 33, and the lift pin 6 is separated from the support table 33. Thereafter, if the stage 21 reaches the processing position, the raising is stopped (right end). Figure 6 Figure 6

[0053] Next, the processing space 50 is supplied with TiCl4gas, purge gas (non-reactive gas), NH3gas, and purge gas in this order, and this series of gas supply is repeated as one cycle to perform the film formation of TiN film on the wafer W. Figure 7 The flow of the gas during the film formation processing is indicated by arrows. If the above-mentioned cycle is repeated for a predetermined number of times and the film formation processing is ended, the wafer W is sent out of the processing vessel 11 in the same manner as the operation performed at the time of the wafer W is sent into the processing vessel 11 as described above. The sending-in of the wafer W into the processing vessel 11, the film formation processing, and the sending-out of the wafer W from the processing vessel 11 are repeated. If the film formation processing is performed on a predetermined number of wafers W as described above, the cleaning processing is performed. Figure 6

[0054] ​​​​​​Furthermore, during the film formation process, as described above, the through-hole 25 is blocked by the head 62 of the lifting pin 6. However, it is possible that a small amount of film-forming gas (TiCl4 gas and NH3 gas) may flow into the through-hole 25 through the tiny gap between the head 62 and the pin support surface 23 of the recess 22, thus forming a film on the side of the rod portion 61 of the lifting pin 6. The film 60 formed on the rod portion 61 grows due to repeated film formation processes on the wafer W. The lifting pin 6 of the film formation apparatus 1 is configured to reliably remove the film 60 during cleaning, preventing defects caused by film 60 residue.

[0055] The operation of the comparative example film-forming apparatus 1A will be explained in detail when describing the cleaning process and the advantages of the structure of the lifting pin 6 during the cleaning process. The film-forming apparatus 1A has the same structure as the film-forming apparatus 1, except that it is equipped with a lifting pin 6A instead of the lifting pin 6. The lifting pin 6A has the same structure as the lifting pin 6, except that it does not have the groove 63.

[0056] The gap between the rod portion 61 of the lifting pin 6A and the hole wall 20 of the through hole 25 is relatively small, making it difficult for cleaning gas to flow. Therefore, there is a concern that even with cleaning, the membrane 60 may not be completely removed, leaving residue after cleaning. Furthermore, the membrane 60 grows due to repeated film-forming processes after cleaning. Figure 8 This indicates the state of the lifting pin 6A, which is concerned about potential problems during the transfer of wafer W from transport mechanism 10 to stage 21 and the movement of stage 21 to processing position when the film 60 has been grown.

[0057] Also as in Figure 6 As explained in the text, after the wafer W is transferred from the transport mechanism 10 to the lifting pin 6A ( Figure 8 The stage 21, from the left end and the second one from the left, rises from the standby position and comes to rest on the wafer support surface 24 near the preheating position of the wafer W. Figure 8 (Center). For example, when the platform 21 rises, the side of the rod 61 contacts the bore wall 20. Due to the formation of the film 60, the friction between the side of the rod 61 and the bore wall 20 increases, thus becoming supported by the bore wall 20. That is, the lifting pin 6A is engaged with the bore wall 20, hindering its descent relative to the platform 21.

[0058] Subsequently, as the stage 21 rises from the preheating position toward the processing position, due to the continued engagement of the lifting pin 6A, even if the support stage 33 separates from the lifting pin 6A, the head 62 of the lifting pin 6A is not retracted into the recess 22 and continues to protrude upward relative to the wafer support surface 24. Figure 8(Second from the right). Therefore, the head 62 continues to support the wafer W, and the portion of the wafer W supported by the head 62 and its vicinity are not placed on the wafer support surface 24, and continue to be suspended relative to the wafer support surface 24.

[0059] Furthermore, these areas were not sufficiently heated before the stage 21 reached the processing position and began film formation. Figure 8 (Right end). Therefore, processing is performed under conditions where the temperature uniformity within the surface of wafer W is low. As a result, the thickness of the TiN film formed on wafer W has a relatively large deviation within the surface of wafer W. Furthermore, it is described that the lifting pin 6A is engaged when the stage 21 moves from the standby position to the preheating position, but this is an example, and there are also cases where engagement occurs at other times.

[0060] As a solution to this problem, it is conceivable to form the rod 61 and the hole wall 20 of the through hole 25 in such a way that the gap between the rod 61 of the lifting pin 6A and the hole wall 20 is relatively large, thereby improving the flow of cleaning gas in the gap and preventing the residue of the membrane 60 during the cleaning process. Specifically, it is conceivable to improve the flow by increasing the diameter of the through hole 25 relative to the diameter of the rod 61.

[0061] However, if the diameter of the through hole 25 is increased relative to the diameter of the rod 61, the rod 61 may tilt to a relatively large extent within the through hole 25, thus raising concerns about potential adverse effects. Specifically, for example, if the tilted rod 61 is placed on the pin support surface 23 and wafer support surface 24 of the recess 22 and supported by them, it is conceivable that the lifting pin 6 cannot be used in this manner. Figure 6 The lifting and lowering motion relative to the stage 21 is described in the diagram. Furthermore, if the gap between the rod 61 and the hole wall 20 of the through-hole 25 becomes too large, heating of the portion overlapping this gap within the surface of the wafer W will not be sufficient, resulting in reduced uniformity of the temperature distribution within that surface. Consequently, there is also concern that the uniformity of the TiN film thickness formed on the wafer W may also decrease.

[0062] Therefore, in the film-forming apparatus 1, a groove 63 constituting a flow path for the cleaning gas is formed in the rod 61 to improve the flowability of the cleaning gas between the rod 61 and the hole wall surface 20 of the through hole 25, thereby reliably removing the film 60 from the rod 61. Hereinafter, the cleaning process in the film-forming apparatus 1 will be described with reference to... Figure 9 And the above Figure 5 Please provide an explanation. Figure 5 This is a schematic diagram showing the flow of gas within the treatment container 11, indicated by arrows. Figure 9 To be further detailed in Figure 5flow of the gas around the lift pin 6 shown in FIG. 6.

[0063] The stage 21 is set in a state where the lift pin 6 is supported by the support table 33 in the standby position. At this time, the upper end of the groove 63 in the stem portion 61 is positioned at a position higher than the pin support surface 23 of the recess 22 constituting the upper surface of the stage 21. The groove 63 is formed so as to reach the lower end of the stem portion 61, and thus, for the lower end of the groove 63, is positioned at a position lower than the lower surface of the stage 21. That is, it becomes a state where the lift pin 6 is disposed so that the groove 63 is from a position higher than the through hole 25 to a position lower than the through hole 25. Then, it becomes a state where the non-active gas is supplied from the shower head 52, and the non-active gas and the cleaning gas are supplied from the gas supply ports 41, 42, respectively, as shown in FIG. 6. Figure 5 These gases flow toward the exhaust port 15 as shown in FIG. 6.

[0064] When the flow of the gas is thus formed, a part of the cleaning gas supplied into the processing container 11 as shown in FIG. 6 enters the groove 63 from the lower side of the stage 21 and flows toward the upper side in the gap constituted by the groove 63 and the hole wall surface 20. Then, the cleaning gas flows out from the gap onto the pin support surface 23 and goes to the exhaust port 15. Figure 9 For the side surface of the stem portion 61 of the lift pin 6, a relatively large gap is formed between the portion where the groove 63 is formed and the hole wall surface 20. Also, the groove 63 is formed from above the pin support surface 23 constituting the upper surface of the stage 21 to the lower surface of the stage 21 as described above, and is formed so that the inlet and outlet of the gas in the gap are large. Thus, for the cleaning gas, the inflow into the gap constituted by the groove 63, the flow in the gap, and the outflow from the gap are performed at a relatively high flow rate.

[0065] Further, in the side surface of the stem portion 61, the gap formed between the portion outside the groove 63 and the hole wall surface 20 of the through hole 25 is relatively small. However, by the cleaning gas flowing in the gap formed between the groove 63 and the hole wall surface 20 at a relatively high flow rate as described above, the flow rate of the cleaning gas also becomes high for the gap formed in the portion outside the groove 63 connected to the gap formed by the groove 63. Thus, the cleaning gas flows at a relatively high flow rate to each portion around the stem portion 61 of the lift pin 6 compared to each portion around the stem portion 61 of the lift pin 6A, and removes the film 60 formed in each portion of the side surface of the stem portion 61.

[0066] Further, for the TiN film attached to each portion in the processing container 11 other than the stem portion 61, it is also removed by being exposed to the cleaning gas. In addition, as the cleaning treatment, it includes, for example, the cleaning gas supplied from the gas supply ports 41, 42 as shown in FIG. 6.

[0067] Figure 5 , Figure 9 ​the stage shown in FIG. 6, the stage shown in FIG. 7, and the stage shown in FIG. 8. The stage shown in FIG. 8 is a stage in which the substrate table 21 is in the standby state and is performed as the lower side cleaning stage. For the upper side cleaning stage, the substrate table 21 is located at the processing position shown in FIG. 7. Figure 7 The processing position shown in FIG. 7, the cleaning gas and the inactive gas are supplied from the shower head 52, and the cleaning gas is supplied from the gas supply port 42. The supplied gases flow into the exhaust port 15 and are exhausted as in the case of the lower side cleaning stage.

[0068] In the upper side cleaning stage, the upper side of the through hole 25 is blocked by the head portion 62 of the lift pin 6, and thus, compared with the lower side cleaning stage, the cleaning gas is less likely to flow into the gap between the rod portion 61 and the hole wall surface 20. Thus, the removal of the film 60 on the rod portion 61 of the lift pin is mainly performed in the lower side cleaning stage. Either the lower side cleaning or the upper side cleaning can be performed first. After the cleaning processing is completed, the substrate table 21 is moved to the standby position shown in FIG. 6 again, and the film 60 is removed from the rod portion 61 of the lift pin 6. Figure 6 Figure 7 The supply into the processing container 11, the film formation on the wafer W, and the supply of the wafer W out of the processing container 11, which are described in FIGS. 6 to 8, are performed.

[0069] As described above, according to the film formation apparatus 1, even when the film 60 is formed on the side surface of the rod portion 61 of the lift pin 6, the film 60 can be reliably removed with high reliability by improving the flow property of the cleaning gas around the rod portion 61 using the groove 63 formed in the rod portion 61 at the time of the cleaning processing. Thus, the deviation of the film thickness in the wafer W caused by the abnormal placement of the wafer W on the substrate table 21 can be suppressed. Figure 8

[0070] Further, for the rod portion 61 of the lift pin 6, as the groove 63, only a part of the peripheral surface of the rod portion 61 is recessed toward the center side of the rod portion 61 compared with the rod portion 61 of the lift pin 6A. Thus, the inclination of the lift pin 6 caused by the increase of the through hole 25 with respect to the rod portion 61 described above is prevented. Further, the gap between the rod portion 61 and the hole wall surface 20 of the through hole 25 can be prevented from becoming too large, and thus, the decrease of the uniformity of the temperature of the wafer W is also suppressed.

[0071] Further, it is described that the film 60 is grown on the rod portion 61, but even when it is assumed that the TiN film is grown on the hole wall surface 20, the abnormal placement of the wafer W caused thereby can occur. However, in the case where the film 60 is formed on the hole wall surface 20 as such, the film 60 can be reliably removed with high reliability by improving the flow property of the cleaning gas in the gap around the rod portion 61 as described in FIGS. 6 to 8, and as a result, the occurrence of such abnormal placement is prevented. Figure 8 Figure 5 Figure 9 ​​​​​

[0072] The shape of the groove 63 formed in the rod portion 61 is not limited to a shape in which the side surface of the groove 63 is orthogonal to the bottom surface of the groove 63. For example, the groove 63 may be formed in a fan shape in cross-section, where the width of the groove 63 narrows as it extends toward the depth of the groove 63. The number of grooves 63 is not limited to four, and any number can be provided. Alternatively, it may be in the following shapes: one groove branches into multiple grooves midway through its extension, or multiple grooves merge midway through their extension.

[0073] Furthermore, the groove 63 is not limited to being formed along the extending direction of the rod 61. For example, as Figure 10 As shown in the side view, a groove 63 can also be formed in a spiral shape on the side of the rod 61. Figure 10 In, also with Figure 9 Similarly, the lifting pin 6 is shown during the lower side cleaning stage, with dashed arrows indicating gas flow. Furthermore, the shape of the lifting pin 6 and the through hole 25 are not limited to the examples described above and can be appropriately modified. For example, these lifting pins 6 and through holes 25 may also be square in cross-sectional view.

[0074] Furthermore, it is described as follows: The stage 21 and the lifting pin 6 are... Figure 9 The position shown is such that the upper end of the groove 63 is positioned above the pin support surface 23 of the recess 22. Clean gas is supplied from the gas supply port 42 located below the stage 21 to remove the film 60. Alternatively, based on this positional relationship between the stage 21 and the lifting pin 6, clean gas can be supplied from the nozzle 52 instead of from the gas supply port 42 to remove the film 60. In other words, when removing the film 60, the supply of clean gas to the groove 63 can be performed from either the upper or lower side of the stage 21. However, in the film-forming apparatus 1, when the stage 21 and the lifting pin 6 are positioned... Figure 9 Given the positional relationship, the exhaust port 15 is located on the upper side of the stage 21. Therefore, in order to supply a sufficient amount of clean gas into the tank 63, it is preferable to supply clean gas from the gas supply port 42 on the lower side of the stage 21, as described above.

[0075] in addition, Figure 11A longitudinal sectional view of the film formation apparatus 1 showing a lift pin 6B having another configuration example of a lift pin. The lower end of the lift pin 6B is fixed to the support stage 33 and is lifted together with the support stage 33. For the lift pin 6B, the head portion 62 is not provided and the groove 63 is formed from the upper end to the lower end of the shaft portion 61. Thus, the lift pin 6B is configured as a whole of the shaft portion 61 and the groove 63 is formed from the upper end to the lower end of the lift pin 6B. In correspondence with the shape of the lift pin 6B, the recess 22 is not provided in the stage 21 and the through-hole 25 is formed from the upper surface to the lower surface of the stage 21. The upper end of the lift pin 6B is protruded and sunk in the wafer support surface 24 of the stage 21 relative to the stage 21 at the standby position by the lifting of the support stage 33 and the handover of the wafer W is performed between the stage 21 and the transport mechanism 10. Also, by cleaning the gas as shown in the lower side cleaning stage Figure 11 the groove 63, the film 60 is removed from the side surface as with the lift pin 6 also for the lift pin 6B.

[0076] As shown as the lift pin 6B, the lift pin can also be configured not to have the head portion 62 and to be fixed to the support stage 33 and by forming the groove 63, the removal of the film 60 is performed more reliably. However, for the lift pin 6B, as fixed to the support stage 33, the abnormal placement of the wafer W caused by the film 60 formed thereby continuing to be supported by the stage 21 does not occur as described in the Figure 8 In addition, when the stage 21 is positioned at the processing position, the lift pin 6B becomes a state of being detached from the through-hole 25 and thus the lift pin 6B detached from the through-hole 25 can be exposed to the cleaning gas supplied from the gas supply port 42 at the upper side cleaning stage. Thus, for the groove 63, it is particularly effective to be formed in the shaft portion 61 of the lift pin configured in such a manner as to have the head portion 62 and the shaft portion 61 and the shaft portion 61 is always positioned in the through-hole 25 as with the lift pin 6.

[0077] Further, for the shape of the lift pin, it can also be appropriately deformed relative to the shapes of the lift pins of the respective examples described and, for example, can be a square rod shape. In addition, as the configuration of the film formation apparatus, it is not limited to the film formation apparatus 1 described and can be an apparatus that performs the film formation of a kind other than the TiN film. It is also not limited to an apparatus that performs the film formation by ALD and can be an apparatus that performs the film formation based on CVD. The film formation apparatus 1 performs the film formation on the wafer W in an environment where the plasma is not formed but can also be configured as an apparatus configuration that performs the film formation in a plasma environment.

[0078] In addition, in the film formation apparatus 1, the exhaust port 15 is provided in the side wall of the processing container 11 in a manner of surrounding the stage 21, and exhaust is performed from the side of the stage 21 toward the outer periphery of the stage 21 during the film formation processing. The apparatus structure provided with the exhaust port 15 is not limited to this, and for example, a structure in which the exhaust port 15 is opened in the bottom of the processing container 11 and exhaust is performed downward from the stage 21 during the film formation processing can also be employed.

[0079] However, in a structure in which the exhaust port 15 is provided in the side wall of the stage 21 to perform exhaust toward the outer periphery of the stage 21 as in the film formation apparatus 1, the exhaust gas flow formed by the exhaust port 15 is difficult to flow as through the through-hole 25. Therefore, if the film formation gas leaks out to the through-hole 25 as described above, it is considered that the film formation gas stagnates in the through-hole 25 and is likely to form the film 60. That is, the present technology is particularly effective for a film formation apparatus in which the exhaust port 15 is provided in the side wall of the stage 21.

[0080] It should be considered that the embodiments disclosed this time are illustrative in all points and are not restrictive. The above-described embodiments can also be omitted, replaced, changed, combined in various forms without departing from the scope of the appended claims and the spirit thereof.

[0081] • Evaluation Test

[0082] An evaluation test associated with the present technology will be described. As Evaluation Test 1, a simulation of measuring the flow rate distribution of the gas in the processing container 11 of the film formation apparatus 1 in the lower side cleaning stage was performed. In this simulation, it was set to supply N2 gas from the gas supply port 42 instead of the cleaning gas. In addition, as Comparative Test 1, a simulation was performed in the same setting as that of Evaluation Test 1 except that the aforementioned lift pin 6A was provided instead of the lift pin 6.

[0083] Figure 12 , Figure 13 are graphs respectively showing the results of Evaluation Test 1 and Comparative Test 1, and are schematic views showing the distribution of the flow rate of the gas around the lift pins 6, 6A. The actual results of each test were obtained as an image in which the flow rate of each portion corresponds to the gradation display of the color by computer graphics, but in Figure 12 , Figure 13 the flow rate distribution was shown by surrounding the region in which the flow rate is approximately constant with an isohypse and labeling a pattern corresponding to the range of the flow rate in the surrounded region.

[0084] As shown in Figure 13 , in Comparative Test 1, the flow rate of the gas in the gap between the rod portion 61 of the lift pin 6A and the hole wall surface 20 of the through-hole 25 is relatively low. However, as shown in Figure 12As shown, in the evaluation test 1, the flow rate of the gas in the gap between the rod portion 61 and the hole wall surface 20 is higher than the flow rate in the above-described gap in the comparative test 1. More specifically, the flow rate at a part of the above-described gap is 0.003 m / sec in the comparative test 1, and the flow rate at a part of the above-described gap is 0.015 m / sec in the evaluation test 1. For the cleaning gas, it goes without saying that the same behavior as that of the N2 gas is exhibited, and thus it is shown from the evaluation test 1 and the comparative test 1 that the flow permeability of the cleaning gas in the gap between the rod portion 61 and the hole wall surface 20 can be improved by providing the groove 63. Thus, it is presumed from these tests that the abnormality of the placement state of the wafer W can be prevented as described in the embodiment.

Claims

1. A film forming apparatus comprising: a process container having a stage on which a substrate is placed, the inside of the process container being evacuated; a first gas supply portion that supplies a film forming gas into the process container in order to form a film on the substrate placed on the stage; a second gas supply portion that supplies a cleaning gas for removing a film formed by the film forming gas in the process container, in a state in which the substrate is not housed in the process container; a through-hole formed in the stage along a longitudinal direction; a substrate support member provided in the through-hole in order to support the substrate, the substrate support member extending in the longitudinal direction; a height changing mechanism that changes a relative height between the stage and the substrate support member in order to switch between a state in which the substrate is supported by the stage and a state in which the substrate is supported by the substrate support member; and a groove formed in a side surface of the substrate support member, the groove constituting a flow path of the cleaning gas.

2. The film forming apparatus according to claim 1, wherein the substrate support member has a stem portion and a head portion that is larger in area than the stem portion when viewed in the extending direction of the substrate support member, and the head portion is provided above the stem portion, a recess is formed in the stage, the recess houses the head portion, and a bottom surface of the recess constitutes a part of an upper surface of the stage, and the groove is provided in the stem portion.

3. The film forming apparatus according to claim 2, wherein an upper end of the groove is located at a position higher than an upper surface of the stage, and a lower end of the groove is located at a position lower than a lower surface of the stage, when the cleaning gas is supplied into the process container.

4. The film forming apparatus according to claim 2, wherein a plurality of grooves are provided in a mutually separated manner when viewed in the extending direction of the substrate support member.

5. The film forming apparatus according to claim 1, wherein an exhaust port is provided in a side wall of the process container in order to exhaust toward an outer periphery of the stage.

6. A film forming method comprising: a process of placing a substrate on a stage, the stage being provided in the inside of a process container, and having a through-hole formed along a longitudinal direction; a process of evacuating the inside of the process container; a process of supplying a film forming gas into the process container from a first gas supply portion in order to form a film on the substrate placed on the stage; a process of supplying a cleaning gas into the process container from a second gas supply portion in order to remove a film formed by the film forming gas in the process container, in a state in which the substrate is not housed in the process container; a process of changing a relative height between the stage and a substrate support member in order to switch between a state in which the substrate is supported by the stage and a state in which the substrate is supported by the substrate support member, using a height changing mechanism; and a process of causing the cleaning gas to flow into a groove formed in a side surface of the substrate support member, the groove constituting a flow path of the cleaning gas.

7. A substrate support member for use in a film forming apparatus, the film forming apparatus comprising: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A processing container in which a stage on which a substrate is placed is provided inside, the inside being exhausted; a first gas supply portion that supplies a film formation gas into the processing container in order to form a film on the substrate placed on the stage; a second gas supply portion that supplies a cleaning gas that removes a film formed by the film formation gas in the processing container, in a state in which the substrate is not housed in the processing container; a through-hole that is formed in the stage along a longitudinal direction; a substrate support member that is provided in the through-hole in order to support the substrate, extending in the longitudinal direction; and a height changing mechanism that changes a relative height between the stage and the substrate support member in order to switch between a state in which the substrate is supported by the stage and a state in which the substrate is supported by the substrate support member, the substrate support member has a groove that is formed in a side surface of the substrate support member, constituting a flow path of the cleaning gas. ​

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