Substrate processing apparatus and substrate processing method

Abstract

The present invention provides a substrate processing apparatus and a substrate processing method for controlling the state of the processing gas in the processing area. [Solution] A substrate processing apparatus that processes a substrate by supplying a processing gas into a processing chamber, comprising: a mounting table provided in the processing chamber on which the substrate is placed; an upper structure provided opposite to the mounting table; a processing area formed between the mounting table and the upper structure; an outer area provided outside the processing area and connected to a gas exhaust mechanism; a gap area connecting the processing area and the outer area; a first gas supply mechanism that supplies the processing gas from the upper structure to the processing area; and a second gas supply mechanism that supplies an inert gas to the gap area.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background Art

[0002] Patent Document 1 discloses a support assembly comprising: a rotatable central base that defines a rotation axis; at least two support arms extending from the central base, each of the support arms having an inner end portion in contact with the central base and an outer end portion; and a heater disposed on the outer end portion of each of the support arms, the heater having a support surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In one aspect, the present disclosure provides a substrate processing apparatus and a substrate processing method that control the state of a processing gas in a processing region.

Means for Solving the Problems

[0005] To solve the above problems, according to one embodiment, a substrate processing apparatus is provided that supplies a processing gas into a processing chamber to process a substrate, comprising: a mounting table provided in the processing chamber on which the substrate is placed; an upper structure provided opposite to the mounting table; a processing area formed between the mounting table and the upper structure; an outer area provided outside the processing area and connected to a gas exhaust mechanism; a gap area connecting the processing area and the outer area; a first gas supply mechanism that supplies the processing gas from the upper structure to the processing area; and a second gas supply mechanism that supplies an inert gas to the gap area. [Effects of the Invention]

[0006] In one aspect, the present disclosure can provide a substrate processing apparatus and a substrate processing method for controlling the state of the processing gas in the processing area. [Brief explanation of the drawing]

[0007] [Figure 1] An example of a schematic diagram showing an example of the configuration of a substrate processing device. [Figure 2] An example of a view of a showerhead from below. [Figure 3] An example of a perspective view illustrating a gas channel for supplying inert gas to an annular gap. [Figure 4] This is an example of a flowchart illustrating a substrate processing method. [Figure 5] An example of a graph showing the pressure change in the processing space at the start of raw material gas supply. [Figure 6] An example of a graph showing the mole fraction of raw material gas in the processing space at the end of the raw material gas supply. [Modes for carrying out the invention]

[0008] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0009] [Substrate Processing Equipment] The substrate processing apparatus 100 according to this embodiment will be described with reference to Figure 1. Figure 1 is an example of a schematic diagram showing an example of the configuration of the substrate processing apparatus 100. The substrate processing apparatus 100 is a device that deposits a desired film on a substrate W such as a wafer by an ALD (Atomic Layer Deposition) process in a processing container 1 under reduced pressure. In the following description, the case in which a TiN film is deposited on the substrate W by the ALD process will be used as an example.

[0010] As shown in Figure 1, the substrate processing apparatus 100 includes a processing container (processing chamber) 1, a mounting table 2, a shower head (superstructure) 3, an exhaust unit (gas exhaust mechanism) 4, a gas supply unit 5, an RF power supply unit 8, and a control unit 9.

[0011] The processing container 1 is made of a metal such as aluminum and has a substantially cylindrical shape. The processing container 1 houses the substrate W. An inlet / outlet 11 for loading or unloading the substrate W is formed in the side wall of the processing container 1, and the inlet / outlet 11 is opened and closed by a gate valve 12. An annular exhaust duct 13 with a rectangular cross-section is provided on top of the main body of the processing container 1. An substantially annular exhaust space (exhaust region, outer space) 13a is formed in the exhaust duct 13. An exhaust port 13b is formed in the outer wall of the exhaust duct 13. A top wall 14 is provided on the upper surface of the exhaust duct 13 so as to close the upper opening of the processing container 1 via an insulating member 16. The space between the exhaust duct 13 and the insulating member 16 is airtightly sealed with a seal ring 15. When the mounting base 2 (and cover member 22) rises to the processing position described later, the partition member 17 partitions the inside of the processing container 1 vertically, forming an upper space and a lower space 1s. Of the upper space of this processing container 1, the space radially outside the processing space 38 and the annular gap (gap region) 39, which will be described later, becomes the exhaust space 13a. Also, of the upper space of this processing container 1, the space radially inside the annular gap 39, which will be described later, becomes the processing space 38.

[0012] The mounting table 2 horizontally supports the substrate W within the processing container 1. The mounting table 2 is formed in the shape of a disc corresponding to the size of the substrate W and is supported by a support member 23. The mounting table 2 is made of a ceramic material such as AlN or a metallic material such as aluminum or nickel alloy, and a heater 21 for heating the substrate W is embedded inside. The heater 21 is powered by a heater power supply (not shown) and generates heat. The output of the heater 21 is controlled by the temperature signal of a thermocouple (not shown) provided near the upper surface of the mounting table 2, thereby controlling the substrate W to a predetermined temperature. The mounting table 2 is provided with a cover member 22 made of ceramic material such as alumina so as to cover the outer peripheral region of the upper surface and the sides.

[0013] A support member 23 is provided on the bottom surface of the mounting platform 2 to support the mounting platform 2. The support member 23 extends from the center of the bottom surface of the mounting platform 2 through a hole formed in the bottom wall of the processing container 1 and downwards to the processing container 1, and its lower end is connected to a lifting mechanism 24. The lifting mechanism 24 causes the mounting platform 2 to move up and down via the support member 23 between the processing position shown by the solid line in Figure 1 and the transport position shown by the dashed line below it, where the substrate W can be transported. A flange portion 25 is attached to the lower part of the support member 23 to the processing container 1, and a bellows 26 is provided between the bottom surface of the processing container 1 and the flange portion 25, which partitions the atmosphere inside the processing container 1 from the outside air and expands and contracts in accordance with the lifting operation of the mounting platform 2.

[0014] Near the bottom surface of the processing container 1, three substrate support pins (only two are shown) are provided, protruding upward from the lifting plate 27a. The substrate support pins 27 are raised and lowered via the lifting plate 27a by a lifting mechanism 28 located below the processing container 1. The substrate support pins 27 are inserted through holes 2a provided in the mounting table 2 at the transport position, and are able to protrude and retract relative to the upper surface of the mounting table 2. By raising and lowering the substrate support pins 27, the substrate W is transferred between the transport mechanism (not shown) and the mounting table 2.

[0015] An upper structure is provided opposite the mounting base 2. The upper structure includes a shower head 3. The shower head 3 supplies processing gas into the processing container 1 in a shower-like manner. The shower head 3 is made of metal, is provided opposite the mounting base 2, and has approximately the same diameter as the mounting base 2. The shower head 3 has a main body 31 fixed to the top wall 14 of the processing container 1, and a shower plate 32 connected below the main body 31. A gas diffusion space 33 is formed between the main body 31 and the shower plate 32, and a gas introduction hole 36 is provided in the gas diffusion space 33 so as to penetrate the top wall 14 of the processing container 1 and the center of the main body 31. An annular projection 34 is formed on the periphery of the shower plate 32, projecting downward (towards the mounting base 2). A gas discharge hole 35 is formed on the flat surface on the inside of the annular projection 34. When the mounting base 2 is in the processing position, a processing space (processing area, reactor space) 38 is formed between the mounting base 2 and the shower plate 32 (superstructure), and the upper surface of the cover member 22 and the annular projection 34 are in close proximity to form an annular gap 39. The height of the processing space 38 is adjusted by the lifting mechanism 24. In other words, the volume of the processing space 38 is adjusted by the lifting mechanism 24. Similarly, the height of the annular gap 39 is adjusted by the lifting mechanism 24. In other words, the Cv value of the annular gap 39 is adjusted by the lifting mechanism 24.

[0016] The exhaust section (gas exhaust mechanism) 4 exhausts the inside of the processing container 1. The exhaust section 4 includes an exhaust pipe 41 connected to the exhaust port 13b, an APC (Auto Pressure Controller) valve 42, an on / off valve 43, and a vacuum pump 44. One end of the exhaust pipe 41 is connected to the exhaust port 13b of the exhaust duct 13, and the other end is connected to the suction port of the vacuum pump 44. Between the exhaust duct 13 and the vacuum pump 44, the APC valve 42 and the on / off valve 43 are provided in order from the upstream side. The APC valve 42 adjusts the pressure in the exhaust space 13a by adjusting the conductance of the exhaust path, and adjusts the pressure in the processing space 38. The on / off valve 43 switches the opening and closing of the exhaust pipe 41.

[0017] The gas supply unit 5 supplies a processing gas into the processing container 1. The gas supply unit 5 has a first gas supply mechanism that supplies processing gases (the first processing gas to the third processing gas) to the processing space 38 of the processing container 1. The first gas supply mechanism has a source gas supply source 51a, a reaction gas supply source 52a, and purge gas supply sources 53a and 54a.

[0018] The source gas supply source 51a supplies the source gas (the first processing gas) to the processing space 38 via the gas supply line 51b. In the following description, for example, TiCl₄ is used as the source gas.

[0019] In the gas supply line 51b, a flow rate controller (MFC: Mass Flow Controller) 51c, a storage tank 51d, and a valve 51e are interposed from the upstream side. The downstream side of the valve 51e in the gas supply line 51b is connected to the gas introduction hole 36. The source gas supplied from the source gas supply source 51a is temporarily stored in the storage tank 51d before being supplied to the processing space 38, is pressurized to a predetermined pressure in the storage tank 51d, and then supplied to the processing space 38. The supply and stop of the source gas from the storage tank 51d to the processing space 38 are performed by opening and closing the valve 51e. By temporarily storing the source gas in the storage tank 51d in this manner, a relatively large flow rate of the source gas can be stably supplied to the processing space 38.

[0020] The reaction gas supply source 52a supplies the reaction gas (the second processing gas) to the processing space 38 via the gas supply line 52b. In the following description, for example, NH₃ is used as the reaction gas.

[0021] The gas supply line 52b is equipped with a flow control device (MFC) 52c, a storage tank 52d, and a valve 52e from the upstream side. The downstream side of the valve 52e in the gas supply line 52b is connected to the gas inlet port 36. The reaction gas supplied from the reaction gas supply source 52a is temporarily stored in the storage tank 52d before being supplied to the processing space 38. After being pressurized to a predetermined pressure in the storage tank 52d, it is supplied to the processing space 38. The supply and cessation of the reaction gas from the storage tank 52d to the processing space 38 are performed by opening and closing the valve 52e. By temporarily storing the reaction gas in the storage tank 52d in this way, a relatively large flow rate of reaction gas can be stably supplied to the processing space 38.

[0022] The purge gas sources 53a and 54a supply an inert gas as a purge gas (third treatment gas) to the processing space 38 via the gas supply lines 53b and 54b. In the following description, for example, N2 is used as the purge gas.

[0023] Flow controllers (MFCs) 53c, 54c and valves 53e, 54e are interposed in the gas supply lines 53b, 54b from the upstream side. The downstream side of valves 53e, 54e in the gas supply lines 53b, 54b is connected to the gas inlet hole 36. Purge gas supplied from purge gas supply sources 53a, 54a is supplied to the processing space 38. The supply and cessation of purge gas from purge gas supply sources 53a, 54a to the processing space 38 is performed by opening and closing valves 53e, 54e.

[0024] Furthermore, gas supply line 53b merges with gas supply line 51b downstream of valve 51e, downstream of valve 53e. In other words, the inert gas supplied from purge gas source 53a and flowing through gas supply line 53b functions as a carrier gas for the raw material gas. In addition, the inert gas flowing through gas supply line 53b functions as a counter gas to prevent the reaction gas flowing through gas supply line 52b from flowing into gas supply lines 51b and 53b.

[0025] Furthermore, gas supply line 54b merges with gas supply line 52b downstream of valve 52e, downstream of valve 54e. That is, the inert gas supplied from purge gas source 54a and flowing through gas supply line 54b functions as a carrier gas for the reaction gas. In addition, the inert gas flowing through gas supply line 54b functions as a counter gas to prevent the raw material gas flowing through gas supply line 51b from flowing into gas supply lines 52b and 54b.

[0026] Then, gas supply line 51b and gas supply line 52b merge downstream of the confluence of gas supply line 51b and gas supply line 53b, and downstream of the confluence of gas supply line 52b and gas supply line 54b, and are connected to the gas inlet hole 36.

[0027] Valves 51e to 54e are, for example, on-off valves that switch between fully open and fully closed. Furthermore, it is preferable that valves 51e to 54e are valves (ALD valves) capable of high-speed opening and closing required in the ALD process.

[0028] During processing, the partition member 17 and the mounting table 2 positioned at the processing location divide the inside of the processing container 1 into an upper space including the processing space 38 and a lower space 1s on the back side of the mounting table 2. In addition, an annular gap 39 is formed between the upper surface of the cover member 22 of the mounting table 2 and the lower surface of the annular projection 34 of the shower plate 32. The processing space 38 is the space radially inward of the annular projection 34 and the annular gap 39 within the upper space of the processing container 1. The exhaust space 13a is the space radially outward of the annular projection 34 and the annular gap 39 within the upper space of the processing container 1. The control unit 9 adjusts the conductance of the annular gap 39 by adjusting the height of the mounting table 2 using the lifting mechanism 28, thereby adjusting the height (gap) between the upper surface of the cover member 22 of the mounting table 2 and the lower surface of the annular projection 34 of the shower plate 32.

[0029] Various gases (raw material gas, reaction gas, purge gas) supplied to the gas inlet 36 diffuse in the gas diffusion space 33 and are supplied into the processing space 38 from the gas discharge 35 of the shower plate 32.

[0030] Furthermore, the gas in the processing space 38 reaches the exhaust space 13a of the exhaust duct 13 via the annular gap 39, and is exhausted from the exhaust port 13b of the exhaust duct 13 through the exhaust piping 41 by the vacuum pump 44 of the exhaust section 4.

[0031] Furthermore, the gas supply unit 5 has a second gas supply mechanism that supplies inert gas to the annular gap 39. The second gas supply mechanism has inert gas supply sources 55a, 56a, 57a, and 58a.

[0032] The inert gas supply source 55a supplies inert gas as an inert gas to the gas supply port 61 via the gas supply line 55b. In the following description, for example, N2 is used as the inert gas.

[0033] The gas supply line 55b is equipped with a flow controller (MFC) 55c, a storage tank 55d, and a valve 55e from the upstream side. The downstream side of the valve 55e in the gas supply line 55b is connected to the gas supply port 61. The inert gas supplied from the inert gas supply source 55a is temporarily stored in the storage tank 55d before being supplied to the gas supply port 61. After being pressurized to a predetermined pressure in the storage tank 55d, it is supplied to the gas supply port 61. The supply and cessation of inert gas from the inert gas supply source 55a to the gas supply port 61 are controlled by opening and closing the valve 55e. By temporarily storing the inert gas in the storage tank 55d in this way, a relatively large flow rate of inert gas can be stably supplied to the gas supply port 61.

[0034] The inert gas supply source 56a supplies inert gas as an inert gas to the gas supply port 61 via the gas supply line 56b. In the following description, N2 will be used as the inert gas.

[0035] The gas supply line 56b is equipped with a flow controller (MFC) 56c, a storage tank 56d, and a valve 56e from the upstream side. The downstream side of the valve 56e on the gas supply line 56b is connected to the gas supply port 61. The inert gas supplied from the inert gas supply source 56a is temporarily stored in the storage tank 56d before being supplied to the gas supply port 61. After being pressurized to a predetermined pressure in the storage tank 56d, it is supplied to the gas supply port 61. The supply and cessation of inert gas from the inert gas supply source 56a to the gas supply port 61 are performed by opening and closing the valve 56e. By temporarily storing the inert gas in the storage tank 56d in this way, a relatively large flow rate of inert gas can be stably supplied to the gas supply port 61.

[0036] The inert gas source 57a supplies inert gas to the gas supply port 61 via the gas supply line 57b. In the following description, for example, N2 is used as the inert gas.

[0037] A flow controller (MFC) 57c and a valve 57e are installed in the gas supply line 57b from the upstream side. The downstream side of valve 57e in the gas supply line 57b is connected to the gas supply port 61. Inert gas supplied from the inert gas supply source 57a is supplied to the gas supply port 61. The supply and cessation of inert gas from the inert gas supply source 57a to the gas supply port 61 are performed by opening and closing valve 57e.

[0038] The inert gas source 58a supplies inert gas to the gas supply port 61 via the gas supply line 58b. In the following description, N2 will be used as the inert gas.

[0039] A flow controller (MFC) 58c and a valve 58e are installed in the gas supply line 58b from the upstream side. The downstream side of valve 58e in the gas supply line 58b is connected to the gas supply port 61. Inert gas supplied from the inert gas supply source 58a is supplied to the gas supply port 61. The supply and cessation of inert gas from the inert gas supply source 58a to the gas supply port 61 are performed by opening and closing valve 58e.

[0040] Furthermore, gas supply line 55b supplies inert gas in the process of supplying raw material gas (S101), which will be described later. Gas supply line 56b supplies inert gas in the process of supplying reaction gas (S103), which will be described later. In addition, the inert gas flowing through gas supply lines 57b and 58b functions as counter gas to prevent backflow.

[0041] The inert gas supplied from the gas supply port 61 passes through the branched passage 62 and the gas discharge passage 63, and is supplied to the annular gap 39 from the gas discharge port 63a located on the opposing surface (lower surface) of the annular projection 34 facing the mounting base 2.

[0042] Figure 2 is an example of a view of the shower head 3 from below. As shown in Figure 2, the gas outlets 63a of the gas discharge passage 63 are arranged in multiple and evenly spaced directions on the surface (bottom surface) opposite the annular projection 34.

[0043] Figure 3 is an example of a perspective view illustrating a gas flow path that supplies inert gas to the annular gap 39. Here, the shape of the gas flow path is shown as it passes through the showerhead 3.

[0044] The branched channel 62 is formed such that the number of branches increases towards the downstream side. The branched channel 62 is also arranged in multiple stages in the vertical direction and has channels (channels 62a, 62c, 62e, 62g) parallel to the opposing surface (bottom surface) of the annular projection 34, and connecting passages (connecting passages 62b, 62d, 62f) that connect the multiple stages of channels. Specifically, the branched channel 62 has channel 62a, connecting passage 62b, channel 62c, connecting passage 62d, channel 62e, connecting passage 62f, and channel 62g.

[0045] The flow path 62a is formed in an arc shape, with a gas supply port 61 connected to the circumferential center of the flow path 62a, and connecting passages 62b connected to the vicinity of both ends of the flow path 62a. The lengths from the gas supply port 61 to each connecting passage 62b are formed to be equal. Two connecting passages 62b are provided at equal intervals in the circumferential direction.

[0046] The flow path 62c is formed in an arc shape, with a gas supply port 61 connected to the circumferential center of the flow path 62c, and connecting passages 62d connected to both ends of the flow path 62c. The length from the gas supply port 61 to each connecting passage 62d is formed to be equal. Four connecting passages 62d are provided at equal intervals in the circumferential direction.

[0047] The flow path 62e is formed in an arc shape, with a gas supply port 61 connected to the circumferential center of the flow path 62e, and connecting passages 62f connected to both ends of the flow path 62e. The length from the gas supply port 61 to each connecting passage 62f is formed to be equal. Eight connecting passages 62f are provided at equal intervals in the circumferential direction.

[0048] Thus, the branched channel 62 has a tournament shape with repeated bifurcations, and the channel length from the gas supply port 61 to each connecting passage 62f that connects to the channel (gas diffusion space) 62g is formed to be equal. This allows the inert gas supplied from the gas supply port 61 to flow uniformly in the circumferential direction into the annular channel 62g.

[0049] Thus, the number of channels in a multi-stage flow system increases from the bottom up, such as one channel 62a, two channels 62c, and four channels 62e. Similarly, the number of connecting passages also increases from the bottom up, such as two connecting passages 62b, four connecting passages 62d, and eight connecting passages 62f.

[0050] The flow path 62g is formed in an annular shape. The flow path 62g functions as a gas diffusion space that diffuses the gas in the circumferential direction. Connecting passages 62f, which are arranged at equal intervals in the circumferential direction, are connected to the upper side of the flow path 62g. Gas discharge passages 63, which are arranged at equal intervals in the circumferential direction, are connected to the lower side of the flow path 62g. This allows the inert gas supplied from the gas supply port 61 to flow uniformly in the circumferential direction into the annular gap 39.

[0051] Here, the channels (channels 62a, 62c, 62e, 62g) are provided parallel to the opposing surface (bottom surface) of the annular projection 34. The connecting passages (connecting passages 62b, 62d, 62f) are provided perpendicular to the opposing surface (bottom surface) of the annular projection 34. As a result, the connections between the channels (channels 62a, 62c, 62e, 62g) and the connecting passages (connecting passages 62b, 62d, 62f) are made at right angles.

[0052] Specifically, the connection between channel 62a and connecting passage 62b is made at a right angle. Furthermore, the connection between connecting passage 62b and channel 62c is made at a right angle. Also, the connection between channel 62c and connecting passage 62d is made at a right angle. Furthermore, the connection between connecting passage 62d and channel 62e is made at a right angle. Also, the connection between channel 62e and connecting passage 62f is made at a right angle. Finally, the connection between connecting passage 62f and channel 62g is made at a right angle.

[0053] This reduces the gas flow velocity at the right-angle connection point of the branched flow path 62, thereby suppressing the generation of pressure differences between multiple flow paths provided at the same stage. Specifically, it suppresses the pressure difference between the two flow paths 62e and the pressure difference between the four flow paths 62e. Thus, it suppresses the circumferential pressure difference in the annular flow path 62g. It also suppresses the circumferential pressure difference in the annular gap 39.

[0054] Returning to Figure 1, the substrate processing apparatus 100 is a capacitively coupled plasma apparatus, where the mounting table 2 is the lower electrode and the shower head 3 is the upper electrode. The mounting table 2, which is the lower electrode, is grounded via a capacitor (not shown).

[0055] The showerhead 3, which serves as the upper electrode, receives high-frequency power (hereinafter also referred to as "RF power") from the RF power supply unit 8. The RF power supply unit 8 includes a power supply line 81, a matching unit 82, and a high-frequency power supply 83. The high-frequency power supply 83 is a power source that generates high-frequency power. The high-frequency power has a frequency suitable for plasma generation. The frequency of the high-frequency power is, for example, within the range of 450 kHz to 100 MHz. The high-frequency power supply 83 is connected to the main body 31 of the showerhead 3 via the matching unit 82 and the power supply line 81. The matching unit 82 has a circuit for matching the output reactance of the high-frequency power supply 83 with the reactance of the load (upper electrode). Although the RF power supply unit 8 has been described as applying high-frequency power to the showerhead 3, which serves as the upper electrode, it is not limited to this. It may also be configured to apply high-frequency power to the mounting base 2, which serves as the lower electrode.

[0056] The substrate processing apparatus 100 also has pressure sensors 91 and 92. Pressure sensor 91 detects the pressure in the processing space 38. Since the conductance of the shower plate 32 is sufficiently large, the pressure in the gas diffusion space 33 and the pressure in the processing space 38 are approximately the same. For this reason, pressure sensor 91 may be installed in the gas diffusion space 33, and the pressure in the processing space 38 may be estimated from the pressure in the gas diffusion space 33. This eliminates the need to install a sensor in the processing space 38, thereby suppressing any impact on the substrate processing. Pressure sensor 92 detects the pressure in the exhaust space 13a. The pressures detected by pressure sensors 91 and 92 are transmitted to the control unit 9.

[0057] The control unit 9 is, for example, a computer and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or auxiliary storage device and controls the operation of the substrate processing device 100. The control unit 9 may be located inside or outside the substrate processing device 100. If the control unit 9 is located outside the substrate processing device 100, the control unit 9 can control the substrate processing device 100 by communication means such as wired or wireless.

[0058] The control unit 9 adjusts the processing conditions for the substrate W based on the height (gap) of the annular gap 39 between the mounting base 2 and the shower head 3 (gas supply mechanism), the supply conditions of the processing gas supplied from the shower head 3 to the processing space 38 (gas type, flow rate, etc.), and the pressure inside the processing container 1 (pressure in the processing space 38, pressure in the exhaust space 13a).

[0059] [Insulating film deposition process using substrate processing equipment] Next, an example of the operation of the substrate processing apparatus 100 will be explained using Figure 4. Figure 4 is an example of a flowchart showing a substrate processing method. Here, the substrate processing apparatus 100 will be explained using the case where a TiN film is deposited on a substrate W using the ALD process as an example.

[0060] First, before starting the substrate processing shown in Figure 4, the substrate W is prepared. Here, the substrate W is loaded into the processing container 1 of the substrate processing apparatus 100 shown in Figure 1. Specifically, the control unit 9 controls the lifting mechanism 28 to lower the mounting table 2 to the transport position (the position of the mounting table 2 shown by the dashed line) and opens the gate valve 12. Next, the substrate W is loaded into the processing container 1 via the loading / unloading port 11 by a transport arm (not shown) and placed on the mounting table 2, which has been temperature-controlled to a predetermined temperature by the heater 21. After the transport arm retracts from the loading / unloading port 11, the gate valve 12 is closed.

[0061] Next, the control unit 9 controls the lifting mechanism 28 to raise the mounting table 2 to the processing position (the position of the mounting table 2 shown by the solid line). This creates an annular gap 39 between the upper surface of the cover member 22 of the mounting table 2 and the lower surface of the annular projection 34 of the shower plate 32. The control unit 9 also controls the angle of the APC valve 42 to reduce the pressure inside the processing container 1 to a predetermined vacuum level using the exhaust unit 4 (vacuum pump 44).

[0062] Furthermore, before starting the ALD process, the control unit 9 opens valves 53e and 54e. This supplies N2 gas (purge gas) from purge gas sources 53a and 54a to the processing space 38. The control unit 9 also opens valves 57e and 58e. This supplies N2 gas (inert gas) from inert gas sources 57a and 58a to the annular gap 39 via the gas outlet 63a. During the film deposition process, valves 53e, 54e, 57e, and 58e are kept open. Here, the exhaust space 13a is connected to the exhaust section 4, and the processing space 38 is connected to the exhaust section 4 via the annular gap 39 and the exhaust space 13a. As a result, the pressure in the exhaust space 13a becomes the reference pressure of the exhaust space 13a, and the pressure in the processing space 38 becomes the reference pressure of the processing space 38. The reference pressure of the exhaust space 13a is lower than the reference pressure of the processing space 38. The reference pressure in the exhaust space 13a and the reference pressure in the processing space 38 are controlled by the height of the annular gap 39 and the exhaust section 4 (APC valve 42).

[0063] Before starting the ALD process, both valves 51e and 52e are closed. While valve 51e is closed, the raw material gas supplied from the raw material gas supply source 51a fills the storage tank 51d. Similarly, while valve 52e is closed, the reaction gas supplied from the reaction gas supply source 52a fills the storage tank 52d. Also, before starting the ALD process, both valves 55e and 56e are closed. While valves 55e and 56e are closed, the inert gas supplied from the inert gas supply sources 55a fills the storage tanks 55d.

[0064] Next, the control unit 9 deposits a desired film (TiN film) on the substrate W by repeating the ALD process (S101-S104). The ALD process consists of supplying a raw material gas (S101), supplying a purge gas (S102), supplying a reaction gas (S103), and supplying a purge gas (S104), with each cycle being repeated a predetermined number of times.

[0065] In step S101, a raw material gas is supplied to the processing space 38. Specifically, the control unit 9 opens valves 51e and 55e. TiCl4 gas (raw material gas) is supplied into the processing space 38 from the raw material gas supply source 51a. As a result, the raw material gas is adsorbed onto the surface of the substrate W, and an adsorption layer of raw material gas is formed on the surface of the substrate W.

[0066] Furthermore, inert gas is supplied into the annular gap 39 from the inert gas supply source 55a. As a result, high pressure is created at the point where the raw material gas flowing through the annular gap 39 from the processing space 38 towards the exhaust space 13a and the inert gas supplied to the annular gap 39 from the gas discharge port 63a merge. That is, a high-pressure section is formed within the annular gap 39. This reduces the amount of raw material gas discharged into the exhaust space 13a through the annular gap 39, trapping the raw material gas within the processing space 38 and increasing the pressure in the processing space 38. By increasing the partial pressure of the raw material gas within the processing space 38, the adsorption efficiency of the raw material gas is improved. After a predetermined time has elapsed, the control unit 9 closes the valves 51e and 55e, and the processing of the control unit 9 proceeds to the next step S102.

[0067] In step S102, purge gas is supplied to the processing space 38. Specifically, the control unit 9 opens valves 53e and 54e. N2 gas (purge gas) is supplied to the processing space 38 from purge gas supply sources 53a and 54a. As a result, any excess raw material gas in the processing space 38 is purged by the purge gas.

[0068] Furthermore, the flow rate of the inert gas supplied from the inert gas supply sources 57a and 58a to the annular gap 39 is small enough to prevent the purge gas containing excess raw material gas from flowing back out of the gas outlet 63a. This suppresses the formation of a high-pressure section within the processing space 38. As a result, the purge gas containing excess raw material gas is exhausted from the annular gap 39 to the exhaust space 13a.

[0069] Valve 51e is closed, and the raw material gas supplied from the raw material gas supply source 51a fills the storage tank 51d. Valve 52e is also closed, and the reaction gas supplied from the reaction gas supply source 52a fills the storage tank 52d. Valves 55e and 56e are also closed, and inert gas fills the storage tanks 55d and 56d.

[0070] Furthermore, the pressure in the exhaust space 13a becomes lower than the pressure in the processing space 38. After a predetermined time has elapsed, the control unit 9 proceeds to the next step S103.

[0071] In step S103, a reaction gas is supplied to the processing space 38. Specifically, the control unit 9 opens valves 52e and 56e. NH3 gas (reaction gas) is supplied into the processing space 38 from the reaction gas supply source 52a. As a result, the raw material gas adsorbed on the surface of the substrate W reacts with the reaction gas to form a single layer of TiN.

[0072] Furthermore, inert gas is supplied into the annular gap 39 from the inert gas supply source 56a. As a result, high pressure is created at the point where the reaction gas flowing through the annular gap 39 from the processing space 38 towards the exhaust space 13a and the inert gas supplied to the annular gap 39 from the gas discharge port 63a merge. In other words, a high-pressure section is formed within the annular gap 39. This reduces the amount of reaction gas discharged to the exhaust space 13a through the annular gap 39, trapping the reaction gas within the processing space 38 and increasing the pressure in the processing space 38. By increasing the partial pressure of the reaction gas within the processing space 38, the reaction efficiency of the reaction gas is improved. After a predetermined time has elapsed, the control unit 9 closes the valves 52e and 56e, and the processing of the control unit 9 proceeds to the next step S104.

[0073] In step S104, purge gas is supplied to the processing space 38. Specifically, the control unit 9 opens valves 53e and 54e. N2 gas (purge gas) is supplied to the processing space 38 from purge gas supply sources 53a and 54a. As a result, excess reaction gases and other substances in the processing space 38 are purged by the purge gas.

[0074] Furthermore, the flow rate of the inert gas supplied from the inert gas sources 57a and 58a to the annular gap 39 is small enough to prevent the purge gas containing excess reaction gas from flowing back out of the gas outlet 63a. This suppresses the formation of a high-pressure section within the processing space 38. As a result, the purge gas containing excess reaction gas is exhausted from the annular gap 39 to the exhaust space 13a.

[0075] Valve 51e is closed, and the raw material gas supplied from the raw material gas supply source 51a fills the storage tank 51d. Valve 52e is also closed, and the reaction gas supplied from the reaction gas supply source 52a fills the storage tank 52d. Valves 55e and 56e are also closed, and inert gas fills the storage tanks 55d and 56d.

[0076] Furthermore, the pressure in the exhaust space 13a becomes lower than the pressure in the processing space 38. After a predetermined time has elapsed, the control unit 9 proceeds to the next step S105.

[0077] In step S105, the control unit 9 determines whether the number of cycles has reached a predetermined number of repetitions, considering the processes shown in steps S101 to S104 as one cycle. If the predetermined number of repetitions has not reached (S105·NO), the control unit 9 returns to step S101 and repeats the cycle from steps S101 to S104. If the predetermined number of repetitions has reached (S105·YES), the control unit 9 terminates the process shown in Figure 4.

[0078] Subsequently, the control unit 9 controls the lifting mechanism 28 to lower the mounting platform 2 to the transport position (the position of the mounting platform 2 shown by the dashed line) and opens the gate valve 12. Next, the substrate W is transported out of the processing container 1 via the loading / unloading port 11 by a transport arm (not shown). After the transport arm has moved away from the loading / unloading port 11, the gate valve 12 is closed.

[0079] Thus, in the process of supplying the raw material gas (S101), the flow rate of the inert gas supplied from the second gas supply mechanism to the annular gap 39 is increased compared to the purging process (S102, S104). Also, in the process of supplying the reaction gas (S103), the flow rate of the inert gas supplied from the second gas supply mechanism to the annular gap 39 is increased compared to the purging process (S102, S104).

[0080] Specifically, in the process of supplying raw material gas (S101), a small flow rate of inert gas is supplied from gas supply lines 57b and 58b, and a large flow rate of inert gas is supplied from storage tank 55d of gas supply line 55b. In the process of supplying reaction gas (S103), a small flow rate of inert gas is supplied from gas supply lines 57b and 58b, and a large flow rate of inert gas is supplied from storage tank 556 of gas supply line 56b. On the other hand, in the processes of supplying purge gas (S102, S104), a small flow rate of inert gas is supplied from gas supply lines 57b and 58b.

[0081] Furthermore, in the process of supplying the raw material gas (S101), the flow rate of the inert gas supplied from the storage tank (first tank) 55d to the annular gap 39 is set according to the pressure of the raw material gas. Also, in the process of supplying the reaction gas (S103), the flow rate of the inert gas supplied from the storage tank (second tank) 56d to the annular gap 39 is set according to the pressure of the reaction gas.

[0082] Next, the pressure changes in the processing space 38 at the start and end of the raw material gas supply process (S101) will be explained using Figures 5 and 6. The same applies to the start and end of the reaction gas supply process (S103), so redundant explanations will be omitted.

[0083] Figure 5 is an example of a graph showing the pressure change in the processing space 38 at the start of raw material gas supply. The vertical axis represents the pressure in the processing space 38 detected by the pressure sensor 91. The horizontal axis represents time.

[0084] Reference numeral 501 (solid line) indicates the pressure change in the processing space 38 when valves 51e and 55e are opened, with the height of the annular gap 39 being 1 mm, inert gas being supplied to the processing space 38 from gas supply lines 53b and 54b, and inert gas being supplied to the annular gap 39 from gas supply lines 57b and 58b.

[0085] Reference numeral 502 (dashed line) indicates the pressure change in the processing space 38 when valve 51e is opened, with the height of the annular gap 39 being 1 mm and inert gas being supplied to the processing space 38 from gas supply lines 53b and 54b. Note that valves 55e to 58e are all closed.

[0086] Reference numeral 503 (dotted line) indicates the pressure change in the processing space 38 when valve 51e is opened, with the height of the annular gap 39 being 1 mm, and inert gas being supplied to the processing space 38 from gas supply lines 53b and 54b, and inert gas being supplied to the annular gap 39 from gas supply lines 57b and 58b. Valve 55e is closed.

[0087] Reference numeral 504 (dotted line) indicates the pressure change in the processing space 38 when valve 51e is opened, with the height of the annular gap 39 being 0.5 mm and inert gas being supplied to the processing space 38 from gas supply lines 53b and 54b. Note that valves 55e to 58e are all closed.

[0088] First, the height of the annular gap 39 differs between reference numeral 502 (dashed line) and reference numeral 504 (dotted line). As shown in reference numeral 504 (dotted line), the pressure in the processing space 38 can be increased by narrowing the height of the annular gap 39 (see white arrow). This improves the adsorption efficiency of the raw material gas. On the other hand, narrowing the height of the annular gap 39 reduces the purging efficiency in the purging process (S102, S104). Furthermore, when the height of the annular gap 39 is increased by controlling the lifting mechanism 28 in the purging process (S102, S104), there is a problem with the operating speed of the lifting mechanism 28.

[0089] In contrast, as shown by reference numeral 501 (solid line), opening valves 51e and 55e can increase the pressure in the processing space 38 compared to the cases shown by reference numerals 502 (dashed line) and 503 (dotted line) (see black arrow). This improves the adsorption efficiency of the raw material gas.

[0090] Furthermore, with reference numeral 501 (solid line), the height of the annular gap 39 can be increased compared to reference numeral 504 (dash-dot line). This improves the purging efficiency in the purging process (S102, S104).

[0091] Furthermore, as shown by comparing symbols 502 (dashed line) and 503 (dotted line), there was almost no effect of trapping the raw material gas by the inert gas supplied to the annular gap 39 from the gas supply lines 57b and 58b. In other words, this indicates that even if inert gas is supplied to the annular gap 39 from the gas supply lines 57b and 58b during the purging process (S102, S104), the impact on the decrease in purging efficiency is small.

[0092] Figure 6 is an example of a graph showing the mole fraction of the raw material gas (TiCl4) in the processing space 38 at the end of the raw material gas supply. The vertical axis represents the mole fraction of the raw material gas (TiCl4) in the processing space 38. The horizontal axis represents time.

[0093] The solid line (symbol 601) shows the change in the mole fraction of the raw material gas (TiCl4) in the processing space 38 when the height of the annular gap 39 is 1 mm, inert gas is supplied to the processing space 38 from gas supply lines 53b and 54b, and inert gas is supplied to the annular gap 39 from gas supply lines 57b and 58b, and then valves 51e and 55e are opened and then closed.

[0094] The symbol 602 (dashed line) indicates the change in the mole fraction of the raw material gas (TiCl4) in the processing space 38 when the valve 51e is opened and then closed, with the height of the annular gap 39 being 0.5 mm and inert gas being supplied to the processing space 38 from the gas supply lines 53b and 54b.

[0095] In the case of symbol 602 (dashed line), the height of the annular gap 39 is narrow, and it takes time t2 for the mole fraction of the raw gas to be halved.

[0096] In contrast, in the case of symbol 601 (solid line), the height of the annular gap 39 can be increased, shortening the time t1 until the mole fraction of the raw gas is halved (t1 <t2)。

[0097] The substrate processing method using the substrate processing apparatus 100 has been described above, but this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible within the scope of the gist of this disclosure as described in the claims. [Explanation of symbols]

[0098] 1. Processing container (processing chamber) 2. Mounting platform 3. Shower head (upper structure) 4. Exhaust section (gas exhaust mechanism) 5. Gas Supply Section (First Gas Supply Organization, Second Gas Supply Organization) 13a Exhaust space (exhaust region, outer space) 24 Lifting mechanism 34 Annular projection 38 Processing space (processing area, reactor space) 39. Annular gap (gap region) 51b~58b Gas supply line 55d Storage tank (Tank 1) 56d Storage tank (second tank) 51e~58e valve 61 Gas supply port 62 Branching channel 62a, 62c, 62e flow path 62b,62d,62f Communication path 62g flow path (gas diffusion space) 63 Gas discharge path 63a Gas outlet 100 Substrate Processing Equipment W board

Claims

1. A substrate processing apparatus that supplies a processing gas into a processing chamber to perform processing on a substrate, A mounting platform for placing the substrate is provided in the processing chamber, An upper structure provided opposite the aforementioned mounting platform, A processing area formed between the mounting base and the upper structure, An outer region provided outside the processing region and connected to a gas exhaust mechanism, The gap region connecting the processing region and the outer region, A first gas supply mechanism that supplies the processing gas from the superstructure to the processing area, The system includes a second gas supply mechanism that supplies an inert gas to the gap region, Circuit board processing equipment.

2. The aforementioned upper structure is The annular projection extends radially outward from the region where the gas discharge holes for discharging the processing gas supplied from the first gas supply mechanism into the processing area are located, and protrudes toward the aforementioned base, The surface of the annular projection facing the mounting base has a gas outlet for discharging the inert gas supplied from the second gas supply mechanism into the gap region. The substrate processing apparatus according to claim 1.

3. The gas outlets are arranged in multiple and evenly in the circumferential direction. The substrate processing apparatus according to claim 2.

4. The aforementioned upper structure is A gas supply port from which the inert gas is supplied from the second gas supply mechanism, Multiple gas outlets, It has a branching channel connecting the gas supply port and a plurality of gas discharge ports, The substrate processing apparatus according to claim 2.

5. The aforementioned branching channel has more branches towards the downstream side. The substrate processing apparatus according to claim 4.

6. The aforementioned branch channel is Multiple stages are provided in the vertical direction, and flow paths are parallel to the opposing surfaces, It has connecting passages that connect multiple stages of flow paths, The substrate processing apparatus according to claim 4.

7. The aforementioned branched channel has a gas diffusion space, The flow path lengths from the gas supply port to the gas diffusion space are all equal. The substrate processing apparatus according to claim 4.

8. The system comprises a first gas supply mechanism and a control unit that controls the first gas supply mechanism, The control unit, A step of supplying raw material gas from the first gas supply mechanism and supplying the inert gas from the second gas supply mechanism, After the step of supplying the raw material gas, the step of supplying purge gas from the first gas supply mechanism, A step of supplying a reaction gas from the first gas supply mechanism and supplying the inert gas from the second gas supply mechanism, After the step of supplying the reaction gas, the step of supplying purge gas from the first gas supply mechanism, Repeat the process. The substrate processing apparatus according to claim 1.

9. The second gas supply mechanism includes a first tank and a second tank for filling with the inert gas, The control unit, In the process of supplying the raw material gas, the inert gas filled in the first tank is supplied to the gap region. In the step of supplying the reaction gas, the inert gas filled in the second tank is supplied to the gap region. The substrate processing apparatus according to claim 8.

10. A substrate processing method for a substrate processing apparatus that supplies a processing gas into a processing chamber to process a substrate, The substrate processing apparatus is A mounting platform for placing the substrate is provided in the processing chamber, An upper structure provided opposite the aforementioned mounting platform, A processing area formed between the mounting base and the upper structure, An outer region provided outside the processing region and connected to a gas exhaust mechanism, The gap region connecting the processing region and the outer region, A first gas supply mechanism that supplies the processing gas from the superstructure to the processing area, The system includes a second gas supply mechanism that supplies an inert gas to the gap region, A step of supplying a raw material gas or reaction gas from the first gas supply mechanism and supplying the inert gas from the second gas supply mechanism, The process includes supplying purge gas from the first gas supply mechanism, Substrate processing method.

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