Substrate mounting method and substrate mounting mechanism

Abstract

The present application provides a substrate placement method and a substrate placement mechanism. When a substrate is placed on a placement surface of a placement table, even if the substrate is laterally offset and is caught in an unintended position, the substrate can be placed in a desired position. The substrate placement method for placing a substrate has the following steps: positioning a lift pin, which is provided so as to be able to protrude into the placement surface, at a substrate exchange position above the placement surface, and exchanging the substrate on the lift pin; then lowering the lift pin on which the substrate is placed to a substrate placement position below the placement surface; and then raising the lift pin by a small distance and returning to the substrate placement position. When the lift pin is lowered from the substrate exchange position to the substrate placement position, if the edge of the substrate is caught on a tapered surface, the edge is released from the tapered surface and the substrate is guided to the placement surface by the step of raising the lift pin by a small distance and returning to the substrate placement position.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a substrate placement method and a substrate placement mechanism. BACKGROUND

[0002] For example, when a substrate such as a semiconductor wafer is processed, the substrate is placed on a placement stage having a horizontal placement surface. In Patent Literature 1, it is described that in order to prevent a substrate from being laterally displaced with respect to a placement stage having a placement surface of a substrate at the bottom of a recess and a tapered surface for guiding a substrate toward the placement surface at the outer periphery of the placement surface, a lower surface of the substrate is placed non-parallel to the placement surface.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2005-50904 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present disclosure provides a substrate placement method and a substrate placement mechanism in which, when a substrate is placed on a placement surface of a placement stage, even if the substrate is laterally displaced and the substrate is caught at an unintended position, the substrate can be placed at a desired position.

[0008] SOLUTION TO PROBLEM

[0009] One technical solution of the present disclosure is a substrate placement method in which, in a chamber of a substrate processing apparatus that processes a substrate, the substrate is placed on a placement surface of a placement stage having the placement surface for placing the substrate and a tapered surface for guiding the substrate provided at the outer periphery of the placement surface, the substrate placement method having: a step of positioning a lift pin provided so as to be able to protrude into the placement surface in a manner so as to protrude above the placement surface, and handing over the substrate to the lift pin; a step of subsequently lowering the lift pin on which the substrate is placed to a substrate placement position below the placement surface; and a step of subsequently raising the lift pin by a small distance and then returning to the substrate placement position, in which, when the lift pin is lowered from the substrate handover position to the substrate placement position, in the case where an edge of the substrate is caught with respect to the tapered surface, the edge is guided toward the placement surface by the step of raising the lift pin by a small distance and then returning to the substrate placement position, thereby releasing the catching of the edge with respect to the tapered surface.

[0010] EFFECT OF THE INVENTION

[0011] According to the present disclosure, even when the substrate is displaced laterally and is clamped at an unintended position, the substrate can be placed at a desired position when the substrate is placed on the placement surface of the placement table. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a perspective view showing one example of a substrate placement mechanism for implementing a substrate placement method of one embodiment.

[0013] Figure 2 is a plan view showing one example of a substrate placement mechanism for implementing a substrate placement method of one embodiment.

[0014] Figure 3 is a sectional view showing one example of a substrate placement mechanism for implementing a substrate placement method of one embodiment.

[0015] Figure 4 is a flowchart showing one embodiment of a substrate placement method.

[0016] Figure 5 is a schematic view showing one embodiment of a substrate placement method.

[0017] Figure 6 is a view for explaining lateral displacement of a wafer on a lift pin.

[0018] Figure 7 is a schematic view showing a state where an edge of a wafer is clamped to a tapered surface.

[0019] Figure 8 is a view for explaining breakage when a wafer is electrostatically attracted in a state where an edge of the wafer is clamped to a tapered surface.

[0020] Figure 9 is a view showing a mechanism for releasing clamping of an edge of a wafer to a tapered surface by a process of lifting a lift pin by a small distance and then returning the wafer to a wafer placement position.

[0021] Figure 10 is a view showing a state of a substrate when preheating is performed.

[0022] Figure 11 is a sectional view showing a substrate processing apparatus to which a substrate placement mechanism is applied. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments will be described with reference to the drawings.

[0024] SUBSTRATE PLACEMENT MECHANISM

[0025] First, one example of a substrate placement mechanism for implementing a substrate placement method of one embodiment will be described. Figure 1is a perspective view of a substrate mounting mechanism, Figure 2 is a plan view thereof, Figure 3 is a sectional view thereof.

[0026] The substrate mounting mechanism 1 is used for mounting a substrate in a chamber maintained in vacuum for a substrate processing apparatus that processes a substrate. As the substrate, a semiconductor wafer (hereinafter, simply referred to as a wafer) is exemplified, and in the following description, a case where the wafer is used as the substrate is described. In addition, the substrate processing apparatus is not particularly limited, and a film formation apparatus that forms a film by CVD, ALD can be exemplified. The CVD, ALD can be plasma CVD or plasma ALD.

[0027] The substrate mounting mechanism 1 has a mounting table 2 for mounting the wafer W and a support member 3 installed in the center of the back surface side of the mounting table 2 in a manner extending downward.

[0028] The mounting table 2 is composed of a dielectric, such as ceramic, for example, aluminum nitride (AlN). In the inside of the mounting table 2, an adsorption electrode 11 that adsorbs the wafer W is embedded in the vicinity of the surface portion thereof, and an electrostatic chuck is constituted. The adsorption electrode 11 is formed of Mo, for example, and is, for example, in a mesh shape. The adsorption electrode 11 is connected to a direct current power source 14 via a power supply line 13, and the wafer W is electrostatically adsorbed by applying a direct current voltage to the adsorption electrode 11. The direct current power source 14 can be turned on / off by a switch (not shown). In addition, the adsorption electrode 11 also functions as a grounding electrode against plasma.

[0029] As shown in FIG. 1, Figure 3 a heater 12 can also be embedded in a lower position of the adsorption electrode 11 in the inside of the mounting table 2. The wafer W is heated by the heater 12, for example, at the time of film formation processing based on CVD, ALD. The heater 12 is connected to a heater power source 16 via a power supply line 15, and the output of the heater 12 is controlled based on a detection value of a temperature sensor (not shown), such as a thermocouple, so that the temperature of the mounting table 2 is controlled.

[0030] A mounting surface 21 that is in a circular ring shape and is used for mounting the wafer W is formed in a position of the surface of the mounting table 2 corresponding to the outer periphery of the wafer W.

[0031] An adsorption surface 22 is formed at a position of about 20 μm to 70 μm lower than the placement surface 21 on the inner side of the placement surface 21. The adsorption surface 22 is a surface that adsorbs the wafer W when the electrostatic chuck is turned on, and is, for example, an embossed surface on which embossing processing is performed. When the wafer W is adsorbed to the adsorption surface 22 by the electrostatic chuck, the wafer W is in close contact with the placement surface 21, and in the case where the substrate processing is CVD or ALD, the formation of a deposition film due to the reaction gas going around to the back surface side of the wafer W can be more effectively suppressed. In particular, in the case where a conductive film is formed by plasma CVD or plasma ALD, the leakage current or arc due to the formation of a conductive deposition film can be suppressed.

[0032] A gas introduction port 24 is formed in the adsorption surface 22, and the backside gas supplied from the gas supply source 18 via the gas supply path 17 is supplied into the space 23 from the gas introduction port 24. The gas supply source 18, the gas supply path 17, and the gas introduction port 24 constitute a backside gas supply mechanism. As the backside gas, a gas having high thermal conductivity such as helium (He) gas is used, and the heat of the stage 2 is transmitted to the wafer W via the backside gas.

[0033] A guide portion 26 for guiding the wafer W is formed in a circular ring shape in a portion of the surface of the stage 2 on the outer side of the placement surface 21. The inner surface of the guide portion 26 becomes a tapered surface 26a for guiding the wafer W and guiding it to the placement surface 21 in the case where the wafer W has shifted in the lateral direction. Figure 3 The taper angle α of the illustrated tapered surface 26a is preferably 50° to 70°, and is, for example, 60°. In this range, the function of guiding the edge of the wafer W can be effectively exerted.

[0034] The inner side of the guide portion 26 becomes a recessed portion 27, and the placement surface 21 is located at the bottom of the recessed portion 27, and the wafer W placed on the placement surface 21 is accommodated in the recessed portion 27. The height of the recessed portion 27, that is, the height of the upper surface of the guide portion 26 from the placement surface 21 is, for example, 0.5 mm to 1 mm.

[0035] A groove portion 25 in a circular ring shape is formed between the placement surface 21 and the guide portion 26. In the case where the processing by the processing device uses a gas, the groove portion 25 is used to accumulate a deposition film generated by the gas. In particular, in the case where the processing by the processing device is processing of forming a conductive film, by accumulating the deposition film in the groove portion 25, the case where the conductive deposition film goes around to the placement surface of the wafer W and cannot exert the function of the electrostatic chuck can be suppressed.

[0036] Three (in the illustrated example) groove portions 25 are formed in the portion of the stage 2 corresponding to the placement surface 21. Figure 3Two) vertical direction through lift pins through holes 28, lift pins 29 through each lift pin through hole 28 in a manner that can protrude from the load surface 21. These lift pins 29 are supported on the support plate 30. Furthermore, lift pins 29 with cylinder or the like drive mechanism 31 by means of support plate 30 for lifting. Lift pins 29 in the wafer exchange position from the load surface 21 protrude and below the wafer load position than the load surface 21, in the wafer exchange position to the lift pins 29 on the wafer W exchange, in the wafer load position wafer W load on the load surface 21.

[0037] Lift pins 29 by drive mechanism 31 by lift control unit 40 control the lifting action, thereby, control the wafer W on the load surface 21 load on the load pins 29. In addition, by the control unit (not shown in Figures 1-3 , refer to the control unit 160 described later) for the substrate placement mechanism 1 heater 12, the voltage applied to the adsorption electrode 11 and other control.

[0038] Electrostatic chuck has the function of correcting the warpage of the wafer W as a substrate. From the point of view of effectively correcting the warpage of the wafer W, it is preferable to adsorb the wafer W by the Johnson-Rahbek force by supplying power to the adsorption electrode 11. The adsorption of the wafer W using the Johnson-Rahbek force slightly reduces the volume resistivity of the dielectric at the film formation temperature to 1 x 10 9 Ω · cm ~ 1 x 10 12 Ω · cm or so, allowing the charge to move. Thus, the amount of charge accumulation can be increased, and a higher adsorption force than the Coulomb force can be obtained. By using AlN as a dielectric, the volume resistivity in the above range can be obtained, and the Johnson-Rahbek force can be effectively exerted.

[0039] In the case of using an electrostatic chuck, the temperature of the stage 2 surface based on the heater 12, that is, the temperature of the wafer W is 200°C or higher is effective. In the case where the heating temperature is 200°C or higher, the warpage of the wafer W as a substrate tends to be large, and the necessity of the function as an electrostatic chuck increases. In the case of 400°C or higher, further in the case of 400 to 700°C, a higher effect can be obtained.

[0040] Furthermore, it is not necessary to provide an electrostatic chuck. In the case where the electrostatic chuck is not provided, the adsorption electrode 11, the adsorption surface 22, and the space 23 are not required, and the structure in which the entire surface of the wafer W is placed on the load surface 21 can be provided.

[0041] <Substrate placement method>

[0042] Next, referring to the flowchart of Figure 4 and Figure 5An embodiment of a substrate mounting method in which the stage 2 of the substrate mounting mechanism 1 configured as described above mounts a wafer W as a substrate will be described with reference to the schematic view of FIG. 10. The substrate mounting method controls the lift pins 29 using the lift control section 40.

[0043] First, as shown in (a) of FIG. 11, the lift pins 29 are positioned at the wafer handover position protruding above the mounting surface 21, and the wafer W fed into the chamber in a vacuum state is handed over to the lift pins 29 (step 1). Figure 5

[0044] Next, as shown in (b) of FIG. 11, the lift pins 29 are lowered to the wafer mounting position below the mounting surface 21 (step 2). As a result, normally, the wafer W is mounted on the mounting surface 21. Figure 5

[0045] Next, as shown in (c) of FIG. 11, the lift pins 29 are raised by a small distance and then returned to the wafer mounting position (step 3). Figure 5

[0046] Hereinafter, the reason for performing step 3 will be described in detail.

[0047] In the middle of the operation of lowering the lift pins 29 on which the wafer W is mounted from the wafer handover position to the wafer mounting position, sometimes, as shown in (a) of FIG. 12, a lateral shift occurs due to the sliding of the wafer W on the lift pins 29, and the edge of the wafer W comes into contact with the tapered surface 26a of the guide 26. This situation is likely to occur in a film formation process based on CVD, ALD performed at a relatively high pressure. The tapered surface 26a is designed to guide the wafer W in the case where the edge of the wafer W comes into contact with the tapered surface 26a. Therefore, normally, even in the case where the edge of the wafer W comes into contact with the tapered surface 26a, the edge of the wafer W slides on the tapered surface 26a due to the self-weight of the wafer W, and the wafer W is mounted on the mounting surface. Figure 6

[0048] However, sometimes, the edge of the wafer W remains caught on the tapered surface 26a, and the wafer W cannot be accurately mounted on the mounting surface 21. As shown in (b) of FIG. 12, this phenomenon is considered to occur because the edge of the wafer W becomes a state of rising on the tapered surface 26a and slightly getting caught, and the frictional resistance locally becomes large. Figure 7

[0049] If such a phenomenon occurs, various undesirable situations can occur. For example, in the case of using an electrostatic chuck, as shown in (a) of FIG. 13, the wafer W is not accurately mounted on the mounting surface 21, and the wafer W is not held by the electrostatic chuck. Figure 8 ​​​​​As shown, when electrostatic chucking is performed on the wafer W, stress is locally applied to the portion of the edge of the wafer W that is caught on the tapered surface 26a, and there is a possibility that a crack will occur. In addition, even in the case where an electrostatic chuck is not used, since the edge of the wafer W is caught on the tapered surface 26a, a space is created between the back surface of the wafer W and the placement surface 21, and thus a deposition film is easily formed on the back surface of the wafer W.

[0050] The frequency at which such a phenomenon occurs is one wafer out of 1000 wafers, but even such a frequency can become a problem in a semiconductor manufacturing process.

[0051] Therefore, in the present embodiment, after the step 2 in which the lift pins 29 are lowered to the wafer placement position is performed, the step 3 in which the lift pins 29 are raised by a small distance and then returned to the wafer placement position is performed, to release the catching of the edge of the wafer at the tapered surface. That is, in this step 3, by temporarily raising the lift pins 29 by a small distance, as shown in (a) of FIG. 10, the wafer W that is caught on the tapered surface 26a is lifted, the edge of the wafer W is separated from the tapered surface 26a, and the local, large frictional resistance is released. Then, when the lift pins 29 are lowered again to the wafer placement position, as shown in (b) of FIG. 10, the edge of the wafer W slides on the tapered surface 26a, and the wafer W is placed on the placement surface 21. Figure 9 Figure 9

[0052] In the case where an electrostatic chuck is used, after the wafer W is placed on the placement surface 21 as above, a direct current voltage is applied to the attraction electrode 11 of the electrostatic chuck to electrostatically chuck the wafer W. As described above, the catching of the edge of the wafer W with respect to the tapered surface 26a can be released by the above-described step 3 to place the wafer W on the placement surface 21, and thus, local cracking of the edge of the wafer can be prevented when the wafer W is electrostatically chucked in this way.

[0053] In addition, in the case where an electrostatic chuck is not used, the case where a space is created between the back surface of the wafer W and the placement surface 21 to form a deposition film on the back surface of the wafer W can also be prevented.

[0054] ​​In step 3, the rising distance (a small distance), i.e., the stroke required to lift the wafer W, needs to be sufficient to release the edge of the wafer W from being locked relative to the tapered surface 26a. From this perspective, the rising distance of the lifting pin 29 is preferably 1 mm or more. However, an excessively large rising distance of the lifting pin 29 can also affect the production cycle time. Therefore, to minimize the impact on the production cycle time, the rising distance of the lifting pin 29 is preferably 3 mm or less. With this level of rising distance, the time required for the lifting pin to rise and then fall again is approximately 1 second or less, having almost no impact on the production cycle time. Based on the above, in step 3, the rising distance of the lifting pin 29 is preferably 1 mm to 3 mm.

[0055] This process is only required for the wafers whose edges are secured to the conical surface 26a, but it is preferable to perform this process on all wafers W. Therefore, there is no need for a mechanism to detect the edge securing of wafer W, and the process does not need to be changed according to the wafer, thus allowing for simple implementation.

[0056] like Figure 10 As shown, the lifting pin 29 can also be stopped midway as needed, bringing the wafer W close to the mounting surface 21, and supplying an inactive gas such as Ar gas into the cavity as a heat-conducting gas to preheat the wafer W. The distance between the wafer W and the mounting surface 21 at this time is set to 0.5mm to 1mm, for example, 1mm.

[0057] The pressure inside the cavity when placing wafer W on the mounting surface 21 is preferably 13.3 Pa (0.1 Torr) or less. When placing wafer W on the mounting surface 21, the lifting pin 29, in which wafer W is placed, descends. However, it has been found that if the pressure inside the cavity before placement is higher than 13.3 Pa (0.1 Torr), lateral displacement is likely to occur when placing wafer W. In other words, by ensuring that the pressure inside the cavity when placing wafer W on the mounting surface 21 is 13.3 Pa (0.1 Torr) or less, the effect of suppressing lateral displacement of wafer W can be achieved.

[0058] The cavity can be set to a low-pressure state from the very beginning of the wafer placement sequence. However, if preheating is performed, the cavity can also be set to a low-pressure state after preheating, while keeping the lifting pin 29 unchanged and the wafer W close to the placement surface 21. Alternatively, even without preheating, the cavity can be set to a low-pressure state after stopping the lifting pin 29 midway.

[0059] <Substrate Processing Apparatus>

[0060] Next, a substrate processing apparatus that uses the substrate mounting mechanism described above will be described.

[0061] Figure 11 is a sectional view showing a substrate processing apparatus.

[0062] The substrate processing apparatus 100 is configured as a film forming apparatus for forming a tungsten (W) film by CVD.

[0063] The substrate processing apparatus 100 has a chamber 101 made of metal in a substantially cylindrical shape. The chamber 101 has an exhaust chamber 151 covering a circular hole 150 formed in a central portion of a bottom wall 101b of a main body and protruding downward. An exhaust pipe 152 is connected to a side surface of the exhaust chamber 151, and an exhaust device 153 having a pressure control valve and a vacuum pump is provided in the exhaust pipe 152. With the exhaust device 153, the inside of the chamber 101 can be exhausted, and the pressure in the chamber 101 can be controlled to a predetermined pressure, i.e., a reduced pressure state.

[0064] A loading / unloading port 157 for loading and unloading a wafer W between the chamber 101 and a wafer transport chamber (not shown) disposed adjacent to the chamber 101, and a gate valve 158 for opening and closing the loading / unloading port 157 are provided in a side wall of the chamber 101.

[0065] The substrate support mechanism 1 having the above-described structure is provided inside the chamber 101. The support member 3 of the substrate support mechanism 1 is attached to the bottom wall of the exhaust chamber 151 via an insulating member 4. In addition, a drive mechanism 31 for raising and lowering the lift pins 29 is attached to the outside of the exhaust chamber 151.

[0066] A showerhead 110 is provided in the top wall 101a of the chamber 101 in opposition to the support table 2 of the substrate support mechanism 1. The showerhead 110 functions as a gas introduction portion. The showerhead 110 has a base member 111 and a shower plate 112, and the outer peripheral portion of the shower plate 112 is threadedly fastened to the base member 111. A gas diffusion space 114 is formed between the base member 111 and the shower plate 112. The base member 111 is supported to the top wall 101a. The shower plate 112 has a gas ejection surface 118 in opposition to the support table 2, and a plurality of gas ejection holes 115 are formed in the shower plate 112. One gas introduction hole 116 is formed in the vicinity of the center of the base member 111. A gas pipe of a gas supply mechanism 120 to be described later is connected to the gas introduction hole 116, and a process gas supplied from the gas supply mechanism 120 is introduced into the chamber 101 in a shower-like manner by the showerhead 110.

[0067] In addition, a heater 147 for heating the showerhead 110 is provided in the base member 111 of the showerhead 110. The heater 147 is supplied with power from a heater power source (not shown) to heat the showerhead 110 to a desired temperature. A heat insulating member 149 is provided in a recess formed in the upper portion of the base member 111.

[0068] The gas supply mechanism 120 has a ClF3 gas supply source 121, a N2 gas supply source 122, a WF6 gas supply source 123, an Ar gas supply source 124, a SiH4 gas supply source 125, and a H2 gas supply source 126. The ClF3 gas is used as a cleaning gas. The WF6 gas is used as a W raw material gas. The SiH4 gas and the H2 gas are used as reducing gases. The N2 gas and the Ar gas are used as carrier and purge gases.

[0069] A gas line 127 is connected to the ClF3 gas supply source 121. A gas line 128 is connected to the N2 gas supply source 122. A gas line 129 is connected to the WF6 gas supply source 123, and a branch line 130 is branched from the gas line 129 at the middle thereof. The branch line 130 is used in a nucleation process to be described later, and the flow rate is strictly controlled. A gas line 131 is connected to the Ar gas supply source 124. The gas line 129 and the branch line 130 are merged with the gas line 131. A gas line 132 is connected to the SiH4 gas supply source 125. A gas line 133 is connected to the H2 gas supply source 126. Further, the gas lines 127, 128, 131, 132, and 133 are connected to a common gas line 139, which is connected to the gas introduction hole 116. The gases pass through the gas introduction hole 116 to the gas diffusion space 114, and are sprayed toward the wafer W in the chamber 101 through the gas ejection holes 115 of the shower plate 112.

[0070] Mass flow controllers 137 as flow controllers and two on-off valves 136 before and after the mass flow controllers 137 are provided in the gas lines 127, 128, 129, 130, 131, 132, and 133. The flow controllers are not limited to the mass flow controllers 137.

[0071] The substrate processing apparatus 100 has a control section 160 for controlling the valves 136, the mass flow controllers 137, the matching box, the high frequency power supply, the lift control section 40 of the substrate mounting mechanism 1, or the DC power supply 14, the heater power supply 16, and the like. The control section 160 has a CPU (computer), and has a main control section for controlling the above-described respective components, an input device, an output device, a display device, and a storage device. A storage medium is provided in the storage device, and a program for controlling the processing performed by the substrate processing apparatus 100, i.e., a processing recipe, is stored in the storage medium, and the main control section controls in such a manner that a prescribed processing recipe stored in the storage medium is called and the substrate processing apparatus 100 performs prescribed processing based on the processing recipe.

[0072] Next, a W film forming process using the above-described substrate processing apparatus 100 will be described.

[0073] Here, a typical example of forming a W film on a TiN film formed in advance as a barrier layer on a wafer W is shown.

[0074] First, before the wafer W is introduced into the chamber 101, a pre-coating process is performed in the chamber 101. The chamber 101 is preferably heated to 350 to 450°C, and the same process as the initiation process, the nucleation process, and the W film formation process described later are sequentially performed under the same conditions to form a pre-coating film on the inner wall of the chamber 101, the surface of the stage 2, the shower head 110, and the like.

[0075] After the pre-coating process is completed, the chamber 101 is purged with Ar gas and N2 gas. Then, after the pressure in the chamber 101 is adjusted, the gate valve 158 is opened, and the wafer W is introduced into the chamber 101 from the vacuum transfer chamber (not shown) through the introduction and discharge port 157 by a transfer mechanism (not shown), and is placed on the placement surface 21 of the stage 2 held at a predetermined temperature by the heater 12.

[0076] When the wafer W is placed on the placement surface 21 of the stage 2, as described above, the lift pin 29 is positioned at the wafer handover position protruding from the placement surface 21, and the wafer W is handed over to the lift pin 29.

[0077] Then, the lift pin 29 is stopped halfway, and the wafer W is preheated while Ar gas is supplied as a heat transfer gas to the chamber in a state where the wafer W is close to the placement surface 21. Then, in a state where the wafer W is stopped at the same position, the chamber 101 is exhausted, and the pressure in the chamber 101 is made to be 13.3 Pa (0.1 Torr) or less. Thus, the lateral shift of the wafer W on the lift pin 29 is suppressed. Then, the lift pin 29 is lowered to a wafer placement position below the placement surface 21. Then, a process of raising the lift pin 29 by a small distance and then returning to the wafer placement position is performed. As described above, by performing this process, even if the wafer W is laterally shifted on the lift pin 29 and the edge of the wafer W that has been laterally shifted is caught in the state of being caught by the tapered surface 26a, the edge of the wafer W can be released from the catch, and the wafer W caught by the tapered surface 26a can be placed on the placement surface 21.

[0078] For the wafer W placed on the stage 2, first, an initiation process for suppressing abnormal grain growth of a W film to be formed later and making it a good surface state is performed. The initiation process is performed by supplying SiH4 gas and H2 gas into the chamber 101 by the shower head 110 to cause SiH x (for example, x = 1 to 3) to be adsorbed on the TiN film.

[0079] After the initiation processing, WF6 gas, Ar gas, H2 gas, N2 gas are supplied into the chamber 101 to perform nucleation processing. At the nucleation processing, the mass flow controller 137 of the branch line 130 branched from the middle of the gas line 129 is set to perform flow control more strictly, and the flow of the WF6 gas is controlled more strictly than at the film formation processing, to perform nucleation of W.

[0080] Next, while Ar gas, H2 gas, N2 gas are being supplied, the gas line 129 is switched to the branch line 130 as the main line, and the WF6 gas is caused to flow at a flow rate higher than at the nucleation processing to perform film formation processing of the W film.

[0081] At the nucleation processing and the film formation processing, the heating temperature is preferably 380°C to 500°C.

[0082] After the film formation processing is performed for a predetermined time, the valve of the gas line 129 is closed, and the supply of the WF6 gas and the like from the WF6 gas supply source 123 is stopped, and the film formation process is ended.

[0083] After that, the chamber 101 is purged with Ar gas, and then the wafer W is pushed up by the lift pins 16, and the wafer W is delivered outside the chamber 11 by the transport arm.

[0084] After the above process is repeated for a given number of wafers W, ClF3 gas is supplied into the chamber 11 to perform cleaning inside the chamber. After cleaning, the pre-coating processing is performed again, and the above processing is repeated.

[0085] At the film formation processing of the W film performed by the substrate processing apparatus 100 as described above, when the wafer W is placed on the placement table 2, the process of causing the lift pins 29 to be raised by a small distance and then returned to the wafer placement position is performed. Thus, in the case where the edge of the wafer W is caught against the tapered surface 26a, the catching can be released, and when the wafer W is electrostatically attracted to the placement table 2 by the electrostatic chuck, the generation of cracks at the edge of the wafer W due to local stress can be prevented.

[0086] In addition, the film formation processing of the W film performed by the substrate processing apparatus 100 is performed at a high temperature of 380°C to 500°C, and warping of the wafer W can be a problem, but by electrostatically attracting the wafer W by the electrostatic chuck, warping of the wafer W can be made difficult to occur. Thus, problems caused by warping of the wafer W, such as deterioration of uniformity of processing, and deposition of a deposit between the wafer W and the placement table 2, can be eliminated.

[0087] <Other Applications>

[0088] The above describes the embodiments, but it should be considered that the embodiments disclosed herein are illustrative in all respects and are not restrictive. The above-described embodiments can be omitted, replaced, changed in various forms without departing from the scope of the claims and the spirit thereof.

[0089] For example, in the above-described embodiments, a structure having an electrostatic chuck is exemplified as a substrate mounting mechanism that implements the substrate mounting method, but the substrate mounting mechanism can not have an electrostatic chuck.

[0090] In addition, a film formation apparatus that forms a W film by CVD is exemplified as a substrate processing apparatus that applies the substrate mounting method, but is not limited thereto. For example, the type of film to be formed is not limited to a W film, but is arbitrary, and in addition, the substrate processing apparatus is not limited to a film formation apparatus. In the above-described embodiments, a structure that does not use plasma is exemplified as a substrate processing apparatus, but plasma can be used.

[0091] Furthermore, the substrate mounting mechanism is not limited to the structure of the above-described embodiments. For example, in the above-described embodiments, an example in which a support member supports a mounting table is shown as a substrate mounting mechanism, but the support member can not be provided and the mounting table can be directly provided on the bottom of the chamber.

[0092] Furthermore, in addition, an example in which a semiconductor wafer is used as a substrate is shown, but the substrate is not limited to a wafer, but can be an FPD substrate, a ceramic substrate, or other substrates.

Claims

1. A substrate placing method in which a substrate is placed on a placing surface of a placing table in a chamber of a substrate processing apparatus that processes a substrate, the placing table having the placing surface for placing the substrate and a tapered surface for guiding the substrate provided at an outer periphery of the placing surface, the tapered surface being formed in a circular ring shape, wherein the substrate placing method has the following steps: a step of positioning a lift pin provided so as to be able to protrude into the placing surface, at a substrate exchange position protruding above the placing surface, and exchanging the substrate on the lift pin; a step of subsequently lowering the lift pin on which the substrate is placed, to a substrate placing position below the placing surface; and a step of subsequently raising the lift pin by a minute distance and then returning to the substrate placing position, in a case where an edge of the substrate is caught on the tapered surface when the lift pin is lowered from the substrate exchange position to the substrate placing position, the edge is released from being caught on the tapered surface by the step of raising the lift pin by a minute distance and then returning to the substrate placing position, and in a process of returning the lift pin to the substrate placing position, the edge slides on the tapered surface, so that the substrate is placed on the placing surface.

2. The substrate placing method according to claim 1, wherein the placing table has an electrostatic chuck that electrostatically attracts the substrate, and the substrate placing method further has a step of electrostatically attracting the substrate by the electrostatic chuck after the step of raising the lift pin by a minute distance and then returning to the substrate placing position.

3. The substrate placing method according to claim 2, wherein the placing table has a heater, and the substrate is heated to 200°C or higher by the heater on the placing table.

4. The substrate placing method according to claim 3, wherein the substrate placing method further has a step of stopping the lift pin on which the substrate is placed at a position midway through lowering to the substrate placing position, and supplying a heat conductive gas into the chamber in a state where the substrate is close to the placing surface, to preheat the substrate.

5. The substrate placing method according to claim 4, wherein the substrate placing method further has a step of making the pressure in the chamber 13.3 Pa or lower in a state where the substrate is close to the placing surface, after the substrate is preheated.

6. The substrate placing method according to claim 1 or 2, wherein the pressure in the chamber is made 13.3 Pa or lower when the substrate is placed on the placing surface.

7. The substrate placing method according to claim 1 or 2, wherein the minute distance is a value that releases the edge from being caught on the tapered surface.

8. The substrate placing method according to claim 7, wherein the minute distance is 1 mm or more.

9. The substrate placing method according to claim 8, wherein the minute distance is 1 mm to 3 mm.

10. A substrate placing mechanism that places a substrate in a chamber of a substrate processing apparatus that processes a substrate, wherein the substrate placing mechanism has: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A stage having a stage surface for placing a substrate and a tapered surface for guiding the substrate provided at an outer periphery of the stage surface, the tapered surface being formed in a circular ring shape; A lift pin provided so as to be able to protrude and sink with respect to the stage surface, and to be lifted between a substrate handover position protruding above the stage surface and a substrate placement position below the stage surface; and A lift control section that controls the lift of the lift pin, The lift control section controls in such a manner that: The lift pin is positioned at the substrate handover position protruding above the stage surface, When the substrate is handed over to the lift pin, the lift pin on which the substrate is placed is lowered to the substrate placement position below the stage surface, Subsequently, the lift pin is raised by a minute distance and then returned to the substrate placement position, When the lift pin is lowered from the substrate handover position to the substrate placement position, in a case where an edge of the substrate is caught in the tapered surface, the edge is released from the catch with respect to the tapered surface by the control of raising the lift pin by a minute distance and then returning to the substrate placement position, and during the return of the lift pin to the substrate placement position, the edge slides on the tapered surface, whereby the substrate is placed on the stage surface.

11. The substrate placement mechanism according to claim 10, wherein The stage has an electrostatic chuck that electrostatically chucks the substrate, and after the control of raising the lift pin by a minute distance and then returning to the substrate placement position, the substrate is electrostatically chucked by the electrostatic chuck.

12. The substrate placement mechanism according to claim 11, wherein The stage has a heater, and the substrate is heated by the heater to 200°C or higher on the stage.

13. The substrate placement mechanism according to claim 12, wherein The lift control section controls in such a manner that the lift pin on which the substrate is placed is stopped at a position halfway through the lowering to the substrate placement position, and a heat-conducting gas is supplied into the chamber in a state where the substrate is close to the stage surface, and the substrate is preheated.

14. The substrate placement mechanism according to claim 13, wherein After the preheating of the substrate, the pressure in the chamber is made to be 13.3 Pa or lower in a state where the substrate is close to the stage surface by the lift control section.

15. The substrate placement mechanism according to any one of claims 10 to 14, wherein The minute distance is 1 mm or more.

16. The substrate placement mechanism according to claim 15, wherein The minute distance is 1 mm to 3 mm.

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