Vacuum processing apparatus and tilt adjustment method

Abstract

To suppress an inclination of a stage to an upper wall of a processing container.SOLUTION: A vacuum processing apparatus comprises a processing container, a stage, a support member, an inclination modification unit, a distance measurement unit, and a control unit. The processing container has an upper wall, a bottom wall, and a side wall, and can maintain a vacuum atmosphere inside. The stage is provided in the processing container to mount a substrate. The stage holds the substrate so that the substrate is opposed to the upper wall. The support member penetrates through the bottom wall of the processing container and supports the stage from below. The inclination modification unit is provided at an end part of the support member located outside the processing container, modifying the inclination of the stage to the upper wall of the processing container. The distance measurement unit measures a distance between the upper wall and the stage at a measurement position on a surface of the upper wall opposed to the stage. The control unit controls an inclination modification unit so that the upper wall and the stage are parallel to each other on the basis of the distance between the upper wall and the stage measured by the distance measurement unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a vacuum processing apparatus and a tilt adjustment method. [Background technology]

[0002] Patent Document 1 listed below discloses a structure in which an adjustment plate for adjusting the inclination of a mounting table on which a substrate is placed is placed below the bottom of a processing vessel, and the bottom of the processing vessel and the adjustment plate are fastened with bolts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-230307 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a vacuum processing apparatus and a tilt adjustment method capable of suppressing tilt of a stage with respect to an upper wall of a processing vessel. [Means for solving the problem]

[0005] One aspect of the present disclosure is a vacuum processing apparatus including a processing vessel, a stage, a support member, a tilt changer, a distance measurement unit, and a control unit. The processing vessel has an upper wall, a bottom wall, and a side wall, and is capable of maintaining a vacuum atmosphere inside. The stage is provided in the processing vessel, and a substrate is placed on the stage. The stage also holds the substrate so as to face the upper wall. The support member supports the stage from below by penetrating the bottom wall of the processing vessel. The tilt changer is provided at an end of the support member located outside the processing vessel, and changes the tilt of the stage with respect to the upper wall of the processing vessel. The distance measurement unit measures the distance between the upper wall and the stage at a measurement position on a surface of the upper wall facing the stage. The control unit controls the tilt changer so that the upper wall and the stage are parallel to each other based on the distance between the upper wall and the stage measured by the distance measurement unit. Effect of the Invention

[0006] Advantageous Effects of Invention The present disclosure provides an advantage in that it is possible to suppress tilt of the stage with respect to the upper wall of the processing vessel. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a vacuum processing apparatus according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing an example of a stage. [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing an example of the structure of the absorbing mechanism. [Figure 4] FIG. 4 is a flowchart illustrating an example of a tilt adjustment method according to an embodiment. [Diagram 5] FIG. 5 is a plan view showing an example of the stage in a state where the optical axis of the laser light is at an angle that passes through the through-hole of the stage. [Figure 6] FIG. 6 is a plan view showing an example of the stage when the stage is at an angle that blocks the laser light. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an example of a vacuum processing apparatus in a state where the stage is at an angle that blocks the laser light. [Figure 8] FIG. 8 is a plan view showing another example of the stage. [Figure 9] FIG. 9 is a plan view showing another example of the stage. [Figure 10] FIG. 10 is a plan view showing another example of the stage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the vacuum processing apparatus and the tilt adjusting method disclosed in the present application will be described in detail with reference to the drawings. Note that the vacuum processing apparatus and the tilt adjusting method disclosed in the following embodiments are not limited to the embodiments.

[0009] In a vacuum processing apparatus, in order to make the surface of the stage on which the substrate is placed parallel to the lower surface of the upper wall, it is necessary to detect the degree to which the surface of the stage on which the substrate is placed is inclined relative to the lower surface of the upper wall. By accurately detecting the inclination of the surface of the stage on which the substrate is placed relative to the lower surface of the upper wall, the amount of adjustment for the stage inclination can be accurately calculated, and the inclination of the stage relative to the upper wall can be suppressed.

[0010] Therefore, the present disclosure provides a technique that can suppress tilt of the stage relative to the upper wall.

[0011] [Configuration of vacuum processing apparatus 100] Fig. 1 is a schematic cross-sectional view showing an example of the configuration of a vacuum processing apparatus 100 according to an embodiment. The vacuum processing apparatus 100 shown in Fig. 1 is an apparatus that performs film formation in a vacuum atmosphere. For example, the vacuum processing apparatus 100 shown in Fig. 1 is an apparatus that performs CVD (Chemical Vapor Deposition) processing using plasma on a substrate W.

[0012] The vacuum processing apparatus 100 includes a processing vessel 1 formed in a substantially cylindrical shape from a metal such as aluminum or nickel having an anodized coating formed on the surface. The processing vessel 1 has a bottom wall 1b and a side wall 1f. The processing vessel 1 is grounded. The processing vessel 1 is configured to be airtight so that a vacuum atmosphere can be maintained inside. An opening 1a is formed in the side wall 1f of the processing vessel 1 for loading and unloading a substrate W. The opening 1a is opened and closed by a gate valve G. A window 1e formed from a light-transmitting material such as quartz is provided in the bottom wall 1b of the processing vessel 1.

[0013] A stage 2 is provided inside the processing vessel 1. The stage 2 is formed in a flat, generally cylindrical shape, for example, from a metal such as aluminum or nickel, or aluminum nitride (AlN) with a metal mesh electrode embedded therein. A substrate W to be processed, such as a semiconductor wafer, is placed on the upper surface of the stage 2. In this embodiment, the lower surface of the stage 2 in an area outside the area of ​​the stage 2 on which the substrate W is placed is formed to be parallel to the upper surface of the stage 2 on which the substrate W is placed. The stage 2 also functions as a lower electrode. The stage 2 is supported from below by a support member 2a. An opening 1c is formed in the bottom wall 1b of the processing vessel 1 below the stage 2. The support member 2a is formed in a generally cylindrical shape, extends vertically downward from the stage 2, and penetrates the opening 1c in the bottom wall 1b of the processing vessel 1. The opening 1c is formed with a diameter larger than the diameter of the support member 2a.

[0014] The stage 2 includes a built-in heater 2b. The heater 2b generates heat in response to power supplied from outside the processing vessel 1, and heats the substrate W placed on the stage 2. Although not shown, a flow path is formed inside the stage 2 to which a coolant whose temperature is controlled by a chiller unit provided outside the processing vessel 1 is supplied. The stage 2 can control the substrate W to a predetermined temperature by heating with the heater 2b and cooling with the coolant supplied from the chiller unit. Note that the heater 2b may not be provided in the stage 2, and the temperature of the substrate W may be controlled by the coolant supplied from the chiller unit.

[0015] Although not shown, an electrode that generates an electrostatic force by an externally supplied voltage is embedded inside the stage 2. The electrostatic force generated by this electrode attracts and holds the substrate W on the upper surface of the stage 2. Although not shown, the stage 2 is provided with lift pins for transferring the substrate W between the stage 2 and a transfer mechanism (not shown) provided outside the processing vessel 1.

[0016] Furthermore, a plurality of through holes 20 are formed in the stage 2, as shown in, for example, Fig. 1 and Fig. 2. Fig. 2 is a plan view showing an example of the stage 2. Each of the through holes 20 is provided on the outer periphery side of the stage 2 with respect to an area 2e on the stage 2 on which the substrate W is placed. Furthermore, in this embodiment, the plurality of through holes 20 are arranged along the outer periphery of the stage 2 at equal intervals. Each of the through holes 20 is arranged, for example, such that an angle formed by a line segment connecting the center O of the stage 2 and each of the through holes 20 is 120°.

[0017] Returning to FIG. 1, the explanation will be continued. A showerhead 3 formed in a substantially circular plate shape from a conductive metal such as aluminum or nickel is provided above the stage 2. The space between the lower surface of the showerhead 3 and the upper surface of the stage 2 is a processing space where a film formation process is performed. The showerhead 3 is supported on the upper part of the stage 2 via an insulating member 1d such as ceramics. This electrically insulates the processing vessel 1 and the showerhead 3. The showerhead 3 forms a ceiling portion of the processing vessel 1. The showerhead 3 is an example of an upper wall.

[0018] The shower head 3 has a top plate 3a and a shower plate 3b. The top plate 3a is provided so as to close the inside of the processing chamber 1 from above. The shower plate 3b is provided below the top plate 3a so as to face the stage 2. A gas diffusion chamber 3c is formed in the top plate 3a. A plurality of gas ejection holes 3d communicating with the gas diffusion chamber 3c are formed in the top plate 3a and the shower plate 3b.

[0019] The top plate 3a is formed with a gas inlet 3e for introducing gas into the gas diffusion chamber 3c. A gas supply unit 35 is connected to the gas inlet 3e via a pipe 36. The gas supply unit 35 has gas supply sources for various gases used in the film formation process and gas supply lines connected to the respective gas supply sources. Each gas supply line is provided with a control device for controlling the flow of gas, such as a valve and a flow rate controller. The gas supply unit 35 supplies various gases, the flow rates of which are controlled by the control devices provided on each gas supply line, to the shower head 3 via the pipe 36. The gases supplied to the shower head 3 diffuse within the gas diffusion chamber 3c and are discharged from the respective gas discharge holes 3d into the processing space below the shower head 3.

[0020] The shower plate 3b is paired with the stage 2 and also functions as an electrode plate for forming a capacitively coupled plasma (CCP) in the processing space. A radio frequency (RF) power supply 30 is connected to the shower head 3 via a matching device 31. The RF power supply 30 supplies RF power to the shower head 3 via the matching device 31. The RF power supplied from the RF power supply 30 to the shower head 3 is supplied from the lower surface of the shower head 3 into the processing space. The gas supplied into the processing space is turned into plasma by the RF power supplied into the processing space. The RF power supply 30 may supply RF power to the stage 2 instead of the shower head 3. In this case, the shower head 3 is grounded. The RF power supply 30 may supply RF power of different frequencies and magnitudes to both the stage 2 and the shower head 3.

[0021] The lower end 2d of the support member 2a that supports the stage 2 is located outside the processing vessel 1 and is connected to the rotating unit 8. The rotating unit 8 has a rotating shaft 80, a vacuum seal 81, and a motor 82. The lower end 2d of the support member 2a is connected to the upper end of the rotating shaft 80. The rotating shaft 80 rotates integrally with the support member 2a about an axis passing through the center O of the stage 2. A slip ring 83 is provided at the lower end of the rotating shaft 80. The slip ring 83 has an electrode and is electrically connected to various wirings for supplying power to components inside the stage 2. For example, the slip ring 83 is electrically connected to wirings that supply power to the heater 2b embedded in the stage 2. Also, for example, the slip ring 83 is electrically connected to wirings that apply a voltage to an electrode for electrostatically adsorbing the substrate W onto the stage 2.

[0022] The motor 82 rotates the rotating shaft 80. The rotation of the rotating shaft 80 rotates the stage 2 via the support member 2a. When the rotating shaft 80 rotates, the slip ring 83 also rotates together with the rotating shaft 80, but the electrical connection between the slip ring 83 and the wiring is maintained.

[0023] The vacuum seal 81 is, for example, a magnetic fluid seal, and is provided around the rotating shaft 80. The vacuum seal 81 can maintain smooth rotation of the rotating shaft 80 while airtightly sealing the rotating shaft 80. Although not shown, the lifting mechanism lifts and lowers the support member 2a, thereby lifting and lowering the stage 2 between the processing position and the transfer position.

[0024] The tilt changing unit 7 is connected to a lower end 2d of the support member 2a via a vacuum seal 81. The tilt changing unit 7 has an absorbing mechanism 70, a bellows 71, a plurality of (for example, six) actuators 72, and a base member 73.

[0025] The bellows 71 is provided so as to surround the periphery of the support member 2a. The upper end of the bellows 71 passes through an opening 70a formed in the absorbing mechanism 70 and is connected to the bottom wall 1b of the processing vessel 1, and the lower end of the bellows 71 is connected to the base member 73. In this way, the bellows 71 air-tightly seals the space between the bottom wall 1b of the processing vessel 1 and the base member 73. The bellows 71 is expandable and contractable in response to the movement of the base member 73.

[0026] The base member 73 is connected to the lower end 2d of the support member 2a located outside the processing vessel 1 via a vacuum seal 81, and can move integrally with the support member 2a and the stage 2. The base member 73 has an opening 73a having a diameter larger than the diameter of the lower end 2d of the support member 2a. The support member 2a passes through the opening 73a, and the lower end 2d of the support member 2a is connected to a rotating shaft 80. The vacuum seal 81 is provided around the rotating shaft 80 connected to the lower end 2d of the support member 2a, and the base member 73 is fixed to the upper surface of the vacuum seal 81. As a result, the base member 73 is connected to the stage 2 via the vacuum seal 81, the rotating shaft 80, and the support member 2a, and can move integrally with the stage 2.

[0027] The multiple actuators 72 are provided in parallel with each other between the bottom wall 1b of the processing vessel 1 and the base member 73, and the inclination of the stage 2 can be changed by changing the inclination of the base member 73 relative to the bottom wall 1b of the processing vessel 1. The multiple actuators 72 may change the position of the base member 73 relative to the bottom wall 1b of the processing vessel 1. The multiple actuators 72 are extendable and contractible, and are rotatably and slidably connected to the base member 73 via a universal joint, and are rotatably and slidably connected to the bottom wall 1b side of the processing vessel 1 via a universal joint.

[0028] The actuators 72 and the base member 73 form a parallel link mechanism that can move the base member 73 in the directions of the X-axis, Y-axis, and Z-axis shown in FIG. 1, and in the directions of rotation around the X-axis, Y-axis, and Z-axis. The movement coordinate system of the parallel link mechanism formed by the actuators 72 and the base member 73 is adjusted in advance to match the coordinate system of the processing vessel 1. The parallel link mechanism connects the bottom wall 1b of the processing vessel 1 and the base member 73, so that the actuators 72 can move the base member 73 relatively to the bottom wall 1b of the processing vessel 1. This allows the tilt of the stage 2 to be adjusted. For example, the actuators 72 can change the tilt of the stage 2 by tilting the base member 73 in a predetermined direction (for example, at least one of the directions of rotation around the X-axis and the Y-axis in FIG. 1) with respect to the bottom wall 1b of the processing vessel 1.

[0029] The absorbing mechanism 70 has an opening 70a that communicates with the inside of the processing vessel 1 via an opening 1c in the bottom wall 1b of the processing vessel 1. The actuators 72 are connected to the absorbing mechanism 70 without being connected to the bottom wall 1b of the processing vessel 1. As a result, even if the bottom wall 1b of the processing vessel 1 is deformed, the stress caused by the deformation of the bottom wall 1b of the processing vessel 1 is absorbed by the absorbing mechanism 70. Therefore, the stress caused by the deformation of the bottom wall 1b of the processing vessel 1 is not transmitted to the actuators 72, and the adjustment accuracy of the tilt of the stage 2 can be prevented from decreasing.

[0030] The absorbing mechanism 70 is provided on the bottom wall 1b of the processing vessel 1, and absorbs deformation of the bottom wall 1b of the processing vessel 1. Fig. 3 is an enlarged cross-sectional view showing an example of the structure of the absorbing mechanism 70. The absorbing mechanism 70 has a plate member 700 and a link member 701.

[0031] The plate member 700 is formed in a plate shape and annular shape, and is disposed below the bottom wall 1b of the processing vessel 1. The plate member 700 is disposed at a distance from the bottom wall 1b of the processing vessel 1 in order to block the transmission of heat and vibration from the processing vessel 1.

[0032] The link member 701 has one end rotatably and slidably connected to the bottom wall 1b of the processing vessel 1, and the other end rotatably and slidably connected to the plate member 700. For example, as shown in FIG. 3, a recess 1b1 is formed in the bottom wall 1b of the processing vessel 1, and a spherical bearing 1b2 is provided in the recess 1b1. A spherical convex portion 702 is formed at one end of the link member 701. The convex portion 702 is connected to the spherical bearing 1b2, so that the link member 701 is rotatably and slidably connected to the bottom wall 1b of the processing vessel 1 via the convex portion 702 and the spherical bearing 1b2. Meanwhile, a recess 703 is formed on the upper surface of the plate member 700 at a position corresponding to the recess 1b1 of the processing vessel 1. A spherical bearing 704 is provided in the recess 703. A spherical convex portion 705 is formed at the other end of the link member 701. By connecting the convex portion 705 to the spherical bearing 704, the link member 701 is connected to the plate member 700 via the convex portion 705 and the spherical bearing 704 so as to be rotatable and slidable.

[0033] The link member 701 rotates in a direction according to the deformation of the bottom wall 1b of the processing vessel 1, thereby suppressing the transmission of the deformation to the plate member 700. For example, when the bottom wall 1b of the processing vessel 1 is deformed in the direction of the arrow in Fig. 3, the link member 701 receives the stress of the deformation of the bottom wall 1b, but rotates together with the bottom wall 1b in the direction of the arrow in Fig. 1 to suppress the transmission of the stress due to the deformation of the bottom wall 1b to the plate member 700. The multiple actuators 72 are connected to the plate member 700. This prevents the stress due to the deformation of the bottom wall 1b of the processing vessel 1 from being transmitted to the multiple actuators 72 via the plate member 700, thereby suppressing a decrease in the adjustment accuracy of the position and tilt of the stage 2.

[0034] A plurality of link members 701 are arranged along the extension direction of the plate member 700. In this embodiment, for example, three link members 701 are provided at approximately equal intervals along the extension direction of the plate member 700. Note that four or more link members 701 may be provided at approximately equal intervals along the extension direction of the plate member 700.

[0035] Further, the distance measurement unit 9 is fixed to the plate member 700. In this embodiment, the distance measurement unit 9 has a light emitting unit and a light receiving unit, the light emitting unit irradiates light (for example, laser light) to an object, and the light receiving unit receives the light reflected from the object. Then, the distance measurement unit 9 measures the distance between the distance measurement unit 9 and the object based on the light irradiated by the light emitting unit and the light received by the light receiving unit. For example, the distance measurement unit 9 measures the distance between the distance measurement unit 9 and the object based on the difference between the phase of the light irradiated by the light emitting unit and the phase of the light received by the light receiving unit. Note that the distance measurement unit 9 may output information such as timing related to the irradiated light and the received light to the control unit 102, and the control unit 102 may measure the distance between the distance measurement unit 9 and the object based on the information received from the distance measurement unit 9.

[0036] In this embodiment, the multiple distance measurement units 9 are fixed to the plate member 700. Since the stress caused by the deformation of the bottom wall 1b of the processing vessel 1 is reduced by the absorption mechanism 70, the stress caused by the deformation of the bottom wall 1b of the processing vessel 1 is not easily transmitted to the plate member 700. Therefore, even if the bottom wall 1b of the processing vessel 1 is deformed, the distance measurement accuracy by the distance measurement units 9 can be maintained high.

[0037] In this embodiment, the plate member 700 is provided with three distance measuring units 9 along the extending direction of the plate member 700. The three distance measuring units 9 are arranged such that the optical axis La of each laser light is located at a predetermined distance from a line parallel to the Z axis passing through the center O of the stage 2. The predetermined distance is the distance from the center O of the stage 2 to the center of each through hole 20 (see FIG. 2). In this embodiment, the bottom wall 1b of the processing vessel 1 is provided with three windows 1e. Each window 1e is arranged between each distance measuring unit 9 and the shower head 3. In this embodiment, the multiple distance measuring units 9 are arranged along the outer periphery of the stage 2 so as to be equally spaced when viewed from a direction intersecting the lower surface of the shower head 3. For example, each distance measuring unit 9 is arranged on the plate member 700 such that an angle formed by a line segment connecting each distance measuring unit 9 from an intersection point of a straight line passing through the center O of the stage 2 and parallel to the Z axis with a plane parallel to the X axis and Y axis is 120°. In another embodiment, the plate member 700 may be provided with four or more distance measuring units 9 along the extending direction of the plate member 700.

[0038] With this configuration, when the stage 2 rotates to an angle where the through hole 20 is located on the optical axis La of the light irradiated from the distance measurement unit 9 toward the shower head 3, the laser light emitted from each distance measurement unit 9 passes through the window 1e and the through hole 20. The laser light that passes through the window 1e and the through hole 20 is irradiated to a position 3f (see FIG. 1) on the lower surface of the shower head 3. Then, the laser light reflected at the position 3f on the lower surface of the shower head 3 passes through the through hole 20 and the window 1e and is received by the distance measurement unit 9. This allows each distance measurement unit 9 to measure the first distance between the shower head 3 and the distance measurement unit 9. In addition, in this embodiment, the three distance measurement units 9 are arranged along the outer periphery of the stage 2 so as to be equidistant when viewed from a direction intersecting the lower surface of the shower head 3. As a result, when the stage 2 rotates to an angle where the through hole 20 is located on the optical axis La of the light irradiated from the distance measurement unit 9 toward the shower head 3, the laser light emitted from each distance measurement unit 9 can pass through the window 1e and the through hole 20 simultaneously. Therefore, the multiple distance measurement units 9 can measure the first distance simultaneously, and the measurement time of the first distance by the multiple distance measurement units 9 can be shortened. Note that the position 3f of the lower surface of the shower head 3 where the laser light is irradiated is preferably a flat surface. The position 3f of the lower surface of the shower head 3 is an example of a measurement position.

[0039] On the other hand, when the stage 2 rotates to an angle that blocks the optical path of the laser light irradiated from the distance measurement units 9 toward the showerhead 3, the laser light emitted from each distance measurement unit 9 passes through window 1e and is irradiated onto the lower surface of the stage 2. Then, the laser light reflected by the lower surface of the stage 2 passes through window 1e and is received by the distance measurement units 9. This allows each distance measurement unit 9 to measure the second distance between the lower surface of the stage 2 and the distance measurement units 9.

[0040] In the vacuum processing apparatus 100, when the pressure inside the processing vessel 1 is controlled to a pressure lower than the atmospheric pressure, the processing vessel 1 is deformed due to the pressure difference with the outside of the processing vessel 1. In addition, the temperature of the processing vessel 1 changes due to the temperature control of the processing vessel 1 and the heat of the substrate processing performed in the processing vessel 1. The processing vessel 1 is also deformed due to the change in temperature of the processing vessel 1. When the processing vessel 1 is deformed, the stress due to the deformation of the processing vessel 1 is transmitted to the stage 2, and the stage 2 may be tilted with respect to the shower head 3. In the processing of the substrate W, in order to improve the uniformity of the processing, it is necessary to improve the uniformity of the distribution and flow of gas in the processing vessel 1, the distribution of RF power, and the like. As one element for this, it is important to keep the shower head 3 and the stage 2 parallel. However, when the processing vessel 1 is deformed, the stage 2 may be tilted with respect to the shower head 3, and the distribution of gas in the processing vessel 1 may be biased.

[0041] Therefore, in the vacuum processing apparatus 100 of this embodiment, a plurality of actuators 72 are provided between the bottom wall 1b of the processing vessel 1 and a base member 73 that is movable integrally with the stage 2. The actuators 72 adjust the inclination of the stage 2 with respect to the shower head 3 by moving the base member 73 relative to the bottom wall 1b. This allows the inclination of the stage 2 to be adjusted so that the shower head 3 and the stage 2 are parallel to each other even if the stage 2 is inclined with respect to the shower head 3 due to deformation of the processing vessel 1. As a result, the vacuum processing apparatus 100 of this embodiment can suppress the inclination of the stage 2 with respect to the shower head 3 due to deformation of the processing vessel 1, and as a result, can improve the in-plane uniformity in substrate processing such as film formation processing.

[0042] An exhaust port 40 is formed in the bottom wall 1b of the processing vessel 1. An exhaust device 42 is connected to the exhaust port 40 via a pipe 41. The exhaust device 42 includes a vacuum pump, a pressure control valve, etc. The exhaust device 42 can reduce the pressure inside the processing vessel 1 to a predetermined vacuum level.

[0043] The control unit 102 has a memory, a processor, and an input / output interface. The memory stores programs executed by the processor, recipes including the conditions for each process, and the like. The processor executes the programs read from the memory, and controls each part of the main body 101 via the input / output interface based on the recipes stored in the memory.

[0044] [Tilt adjustment method] 4 is a flowchart showing an example of a tilt adjustment method according to an embodiment of the present invention. Each step shown in FIG.

[0045] First, the substrate W is loaded into the processing vessel 1 (S10). In step S10, the gate valve G is opened, and the substrate W is loaded into the processing vessel 1 through the opening 1a by a transfer device (not shown), and placed on the stage 2. Then, the gate valve G is closed, and the substrate W is attracted and held on the upper surface of the stage 2 by electrostatic force.

[0046] Next, adjustment of the pressure in the processing vessel 1 is started (S11). In step S11, gas is supplied from the gas supply unit 35 into the processing vessel 1 via the shower head 3, the gas in the processing vessel 1 is exhausted by the exhaust device 42, and the pressure in the processing vessel 1 is adjusted to a predetermined pressure by the pressure adjustment valve in the exhaust device 42. The predetermined pressure is, for example, a pressure when processing the substrate W.

[0047] Next, adjustment of the temperature of the substrate W is started (S12). In step S12, power is supplied to the heater 2b built into the stage 2, and the substrate W is heated. A coolant whose temperature is controlled by a chiller unit is supplied to a flow path formed inside the stage 2, thereby cooling the stage 2 and cooling the substrate W via the stage 2. The temperature of the substrate W is adjusted to a predetermined temperature by heating by the heater 2b and cooling by the coolant. The predetermined temperature is, for example, a temperature at which the substrate W is processed. The order of steps S11 and S12 may be reversed, and steps S11 and S12 may be performed simultaneously.

[0048] Next, the control unit 102 determines whether the pressure in the processing vessel 1 has been adjusted to within a predetermined range and the temperature of the substrate W has been adjusted to within a predetermined range (S13). If the pressure in the processing vessel 1 has not been adjusted to within the predetermined range or the temperature of the substrate W has not been adjusted to within the predetermined range (S13: No), the control unit 102 executes the process shown in step S13 again.

[0049] On the other hand, when the pressure in the processing vessel 1 is adjusted to a pressure within a predetermined range and the temperature of the substrate W is adjusted to a temperature within a predetermined range (S13: Yes), the control unit 102 controls the rotation unit 8 as follows. That is, the control unit 102 controls the rotation unit 8 to rotate the stage 2 until the position of the through hole 20 of the stage 2 is at an angle where the optical axis La of the laser light irradiated from the distance measurement unit 9 toward the shower head 3 passes (S14). Step S14 is an example of a first rotation step. As a result, as shown in, for example, FIG. 1 and FIG. 5, the optical axis La of the laser light irradiated from each distance measurement unit 9 passes through the through hole 20 and is irradiated to the position 3f of the lower surface of the shower head 3. Then, the laser light reflected at the position 3f of the lower surface of the shower head 3 passes through the through hole 20 and is received by the distance measurement unit 9.

[0050] 2, for example, each of the through holes 20 is provided on the outer periphery side of the stage 2 with respect to a region 2e on the stage 2 on which the substrate W is placed. Therefore, even when the substrate W is placed on the stage 2, the laser light irradiated from each of the distance measuring units 9 can pass through the through holes 20.

[0051] Next, the distance measurement unit 9 measures a first distance between the distance measurement unit 9 and the shower head 3 based on the laser light irradiated to the shower head 3 and the reflected light received from the shower head 3 (S15). Step S15 is an example of a first measurement step. The first distance measured by each distance measurement unit 9 is output to the control unit 102.

[0052] Next, the control unit 102 controls the rotation unit 8 to rotate the stage 2 until the stage 2 reaches an angle at which the stage 2 blocks the laser light irradiated from the distance measurement units 9 to the shower head 3 (S16). Step S16 is an example of a second rotation step. As a result, the laser light irradiated from each distance measurement unit 9 toward the shower head 3 is blocked by the through hole 20, as shown in, for example, FIGS. 6 and 7. Therefore, the laser light irradiated from each distance measurement unit 9 is reflected at position 2c on the lower surface of the stage 2 and received by the distance measurement unit 9.

[0053] Next, the distance measurement unit 9 measures a second distance between the distance measurement unit 9 and the underside of the stage 2 based on the laser light irradiated to the stage 2 and the reflected light received from the stage 2 (S17). Step S17 is an example of a second measurement step. The second distances measured by each distance measurement unit 9 are output to the control unit 102. Note that the order of the series of steps S14 to S15 and the series of steps S16 to S17 may be reversed.

[0054] Next, the control unit 102 calculates the distance between the bottom surface of the shower head 3 and the bottom surface of the stage 2 at each position where the distance measurement unit 9 is provided, based on the first distance and the second distance measured by each distance measurement unit 9 (S18). Three distance measurement units 9 are provided below the stage 2. Therefore, in step S18, the distance between the bottom surface of the shower head 3 and the bottom surface of the stage 2 is calculated at the three positions where the distance measurement units 9 are provided.

[0055] Next, the control unit 102 calculates the inclination of the lower surface of the stage 2 with respect to the lower surface of the showerhead 3 (S19). In this embodiment, the distance between the lower surface of the showerhead 3 and the lower surface of the stage 2 is calculated at three locations where the distance measuring units 9 are provided, so that the relative inclination of the lower surface of the stage 2 with respect to the lower surface of the showerhead 3 can be calculated.

[0056] Here, when the substrate W is processed, the pressure inside the processing vessel 1 is controlled to a pressure lower than atmospheric pressure. When the pressure inside the processing vessel 1 is controlled to a pressure lower than atmospheric pressure, the processing vessel 1 may be deformed due to the pressure difference with the outside of the processing vessel 1. Also, when the substrate W is processed, the temperature of the members of the processing vessel 1 is controlled to a temperature different from the temperature of the outside air depending on the processing conditions. When the temperature of the members of the processing vessel 1 is controlled to a temperature different from the temperature of the outside air, the temperature of the members is transmitted to the processing vessel 1, causing a change in the temperature of the processing vessel 1. When the temperature of the processing vessel 1 changes, the processing vessel 1 may be deformed.

[0057] In this embodiment, after it is determined in step S13 that the pressure in the processing vessel 1 is adjusted to a pressure within a predetermined range and the temperature of the substrate W is adjusted to a temperature within the predetermined range, the first distance and the second distance are measured by each distance measurement unit 9. In this embodiment, the pressure within the predetermined range is, for example, the pressure when processing the substrate W. Also, in this embodiment, the temperature within the predetermined range is, for example, the temperature when processing the substrate W. In this embodiment, the first distance and the second distance are measured after the pressure and temperature are adjusted to those when processing the substrate W. Then, based on the measured first distance and second distance, the relative inclination of the lower surface of the stage 2 with respect to the lower surface of the shower head 3 is calculated. This makes it possible to calculate the relative inclination of the lower surface of the stage 2 with respect to the lower surface of the shower head 3 in the environment in which the substrate W is actually processed.

[0058] Returning to FIG. 4, the explanation will be continued. Based on the tilt calculated in step S19, the control unit 102 changes the tilt of the stage 2 so that the lower surface of the shower head 3 and the lower surface of the stage 2 are parallel (S20). Step S20 is an example of a changing process. In step S20, the control unit 102 calculates the tilt of the stage 2 that offsets the tilt calculated in step S19. Then, the control unit 102 controls the tilt changing unit 7 so that the stage 2 has the calculated tilt. This makes it possible to position the lower surface of the shower head 3 and the substrate W placed on the stage 2 parallel to each other.

[0059] After the change in the tilt of the stage 2 in step S20 is completed, processing is carried out on the substrate W (S21). Then, the tilt adjustment method shown in this flowchart is completed.

[0060] An embodiment has been described above. The vacuum processing apparatus 100 of this embodiment includes a processing vessel 1, a stage 2, a support member 2a, an inclination changer 7, a distance measurement unit 9, and a control unit 102. The processing vessel 1 has an upper wall, a bottom wall 1b, and a side wall 1f, and can maintain a vacuum atmosphere inside. The stage 2 is provided in the processing vessel 1, and a substrate W is placed on the stage 2. The stage 2 also holds the substrate W so as to face the upper wall. The support member 2a penetrates the bottom wall 1b of the processing vessel 1 and supports the stage 2 from below. The inclination changer 7 is provided at a lower end 2d of the support member 2a located outside the processing vessel 1, and changes the inclination of the stage 2 with respect to the upper wall of the processing vessel 1. The distance measurement unit 9 measures the distance between the upper wall and the stage 2 at a position 3f on the surface of the upper wall facing the stage 2. The control unit 102 controls the tilt changing unit 7 so that the upper wall and the stage 2 become parallel to each other, based on the distance between the upper wall and the stage 2 measured by the distance measuring unit 9. This makes it possible to suppress the tilt of the stage 2 with respect to the upper wall of the processing vessel 1.

[0061] In the above embodiment, the distance measuring units 9 are provided corresponding to the three or more positions 3f on the surface of the upper wall. The controller 102 controls the tilt changing unit 7 so that the upper wall and the stage 2 become parallel to each other, based on the distances between the upper wall and the stage 2 measured by the respective distance measuring units 9. This makes it possible to more accurately suppress the tilt of the stage 2 with respect to the upper wall of the processing vessel 1.

[0062] Moreover, the vacuum processing apparatus 100 in the above-described embodiment includes a rotating unit 8 that rotates the stage 2. The distance measuring unit 9 is provided below the stage 2, and irradiates light toward each position 3f, and measures the distance between the distance measuring unit 9 and the object based on the irradiated light and the light reflected and received from the object on the optical axis of the irradiated light. The stage 2 has a through hole 20 formed therein. The control unit 102 controls the rotating unit 8 so that the stage 2 rotates until the position of the through hole 20 of the stage 2 is at an angle where the light irradiated along the optical axis passes through the through hole 20, and then causes the distance measuring unit 9 to measure a first distance from the distance measuring unit 9 to the upper wall. The control unit 102 also controls the rotating unit 8 so that the stage 2 rotates until the angle where the stage 2 blocks the light irradiated along the optical axis, and then causes the distance measuring unit 9 to measure a second distance from the distance measuring unit 9 to the lower surface of the stage 2. The control unit 102 also calculates the distance between the upper wall and the stage 2 based on the difference between the first distance and the second distance. In this way, the inclination of stage 2 with respect to the upper wall of processing vessel 1 can be calculated.

[0063] In the above embodiment, the distance measuring units 9 are disposed at equal intervals along the outer periphery of the stage 2 when viewed from a direction intersecting the surface of the upper wall. This makes it possible to more accurately calculate the inclination of the stage 2 with respect to the upper wall of the processing vessel 1.

[0064] In the embodiment described above, the through-holes 20 are formed in an area outside the area on the stage 2 where the substrate W is placed. This allows the light irradiated from each distance measuring unit 9 to pass through the through-holes 20 even when the substrate W is placed on the stage 2.

[0065] In the above embodiment, the number of through holes 20 is the same as the number of distance measurement units 9, and the multiple through holes 20 are arranged at equal intervals along the outer periphery of the stage 2. This allows the multiple distance measurement units 9 to measure the first distances simultaneously, and the measurement time for the first distances by the multiple distance measurement units 9 can be shortened.

[0066] In the above embodiment, the plate member 700 is connected to the bottom wall 1b of the processing vessel 1 via the link member 701 that absorbs deformation of the bottom wall 1b. The tilt changing unit 7 changes the tilt of the stage 2 based on the plate member 700. The distance measuring unit 9 is fixed to the plate member 700. This makes it possible to maintain high accuracy in measuring the distance by the distance measuring unit 9 even if the bottom wall 1b of the processing vessel 1 is deformed.

[0067] Furthermore, in the above-described embodiment, the control unit 102 causes the distance measurement unit 9 to measure the distance between the upper wall and the stage 2 after the substrate W is placed on the stage 2, the pressure inside the processing vessel 1 is adjusted to the pressure used in processing the substrate W, and the temperature of the substrate W is adjusted to the temperature used in processing the substrate W. This makes it possible to measure the distance between the upper wall and the stage 2 in an environment in which the substrate W is actually processed. This makes it possible to calculate the relative inclination of the stage 2 with respect to the upper wall in an environment in which the substrate W is actually processed.

[0068] The tilt adjustment method in the above embodiment includes a first rotation step, a first measurement step, a second rotation step, a second measurement step, and a change step. In the first rotation step, the stage 2 is rotated until the position of the through hole 20 formed in the stage 2 on which the substrate W is placed is at an angle where the light irradiated along the optical axis from the distance measurement unit 9 provided below the stage 2 passes through the through hole 20. In the first measurement step, a first distance between the distance measurement unit 9 and the upper wall is measured based on the light irradiated along the optical axis from the distance measurement unit 9 to the upper wall of the processing vessel 1 and the light received by the distance measurement unit 9. In the second rotation step, the stage 2 is rotated until the angle where the stage 2 blocks the light irradiated from the distance measurement unit 9 along the optical axis. In the second measurement step, a second distance between the distance measurement unit 9 and the lower surface of the stage 2 is measured based on the light irradiated along the optical axis from the distance measurement unit 9 and the light received by the distance measurement unit 9. In the changing step, the distance between the upper wall and the stage 2 is calculated based on the difference between the first distance and the second distance, and the inclination of the stage 2 with respect to the upper wall is changed based on the calculated distance so that the upper wall and the stage 2 become parallel to each other. This makes it possible to suppress the inclination of the stage 2 with respect to the upper wall of the processing vessel 1.

[0069] [others] It should be noted that the technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0070] For example, in the above embodiment, a plurality of through holes 20 are formed in the stage 2 along the outer periphery of the stage 2, but the disclosed technology is not limited thereto. As another embodiment, one through hole 20 may be formed in the stage 2, for example, as shown in FIG. 8. Even in such a configuration, by rotating the stage 2, the laser light irradiated from each distance measurement unit 9 toward the shower head 3 can pass through the through hole 20. In addition, by rotating the stage 2, the laser light irradiated from each distance measurement unit 9 toward the shower head 3 can be blocked by the stage 2. Note that, when one through hole 20 is formed in the stage 2, it is preferable that the through hole 20 is formed in the vicinity of the position where the reference shape OF indicating the orientation of the substrate W is disposed, for example, as shown in FIG. 8. This can reduce the influence of the through hole 20 of the stage 2 on the uniformity of the processing of the substrate W.

[0071] In the above embodiment, the stage 2 is formed with a plurality of through holes 20 along the outer periphery of the stage 2, but the disclosed technology is not limited thereto. As another embodiment, the stage 2 may be formed with a plurality of convex portions 2f and a plurality of concave portions 2g along the outer periphery of the stage 2, for example, as shown in FIG. 9. In the example of FIG. 9, three convex portions 2f and three concave portions 2g are formed on the stage 2 along the outer periphery of the stage 2. In the example of FIG. 9, the three concave portions 2g are arranged along the outer periphery of the stage 2 at equal intervals. Each concave portion 2g is arranged such that, for example, the angle between the center O of the stage 2 and each concave portion 2g is 120°. In the example of FIG. 9, the lower surface of the convex portion 2f is formed parallel to the upper surface of the stage 2 on which the substrate W is placed. Even in such a configuration, the stage 2 is rotated so that the laser light irradiated from each distance measurement unit 9 toward the shower head 3 passes through the concave portion 2g. Moreover, by rotating the stage 2, the laser light irradiated from each distance measuring unit 9 toward the shower head 3 can be blocked by the convex portion 2f. Note that, in the example of Fig. 9, one concave portion 2g may be formed in the vicinity of the position where the reference shape OF of the substrate W is arranged, as in Fig. 8.

[0072] In the above embodiment, the stage 2 is formed with a plurality of through holes 20 along the outer periphery of the stage 2, but the disclosed technology is not limited thereto. As another embodiment, as shown in FIG. 10, for example, a single convex portion 2f may be formed on the outer periphery of the stage 2, protruding from the outer periphery of the stage 2 in a direction away from the stage 2. In the example of FIG. 10, the lower surface of the convex portion 2f is formed to be parallel to the upper surface of the stage 2 on which the substrate W is placed. Even in this configuration, the laser light can be irradiated from each distance measurement unit 9 to the shower head 3 by rotating the stage 2 to an angle at which the convex portion 2f does not block the laser light irradiated from the distance measurement unit 9 to the shower head 3. In addition, by rotating the stage 2 to an angle at which the convex portion 2f blocks the laser light irradiated from the distance measurement unit 9 to the shower head 3, the laser light irradiated from the distance measurement unit 9 to the shower head 3 can be reflected by the lower surface of the convex portion 2f. 10, a plurality of protrusions 2f may be formed along the outer periphery of the stage 2, similar to the protrusions 2f in FIG.

[0073] In the above embodiment, the distance measurement unit 9 measures the first distance and the second distance using a laser beam, but the disclosed technology is not limited to this. The distance measurement unit 9 may measure the first distance and the second distance using a beam other than a laser beam, or may measure the first distance and the second distance using another electromagnetic wave such as a millimeter wave.

[0074] Furthermore, when a process such as film formation is repeated on the substrate W, reaction by-products (so-called deposits) adhere to the inside of the processing vessel 1, such as the lower surface of the showerhead 3. When such deposits adhere to the lower surface of the showerhead 3, the measurement accuracy of the distance between the distance measurement unit 9 and the lower surface of the showerhead 3 decreases. Therefore, it is preferable that the measurement of the first distance and the second distance by the distance measurement unit 9 is performed after cleaning is performed to remove the deposits in the processing vessel 1 and before processing of the substrate W is started. This allows the first distance and the second distance to be measured with higher accuracy.

[0075] Furthermore, the first distance measured before processing of the substrates W is performed may be stored as a reference value, and the first distance may be remeasured each time processing of a predetermined number of substrates W is completed. Then, the thickness of the deposit adhering to the lower surface of the showerhead 3 may be estimated from the measured first distance and the reference value. This makes it possible to determine the timing of cleaning the inside of the processing vessel 1 in accordance with the actual thickness of the deposit.

[0076] In the above embodiment, each distance measuring unit 9 measures the first distance and the second distance, but the disclosed technology is not limited to this. As another embodiment, the distance measuring unit 9 for measuring the first distance and the distance measuring unit 9 for measuring the second distance may be separately provided on the plate member 700. In this case, the distance measuring unit 9 for measuring the first distance irradiates the laser light toward the lower surface of the shower head 3 from a position where the laser light is not always blocked by the stage 2, and the distance measuring unit 9 for measuring the second distance irradiates the laser light toward the lower surface of the stage 2 at all times. This allows the first distance and the second distance to be measured without rotating the stage 2, thereby shortening the time required to measure the distance between the shower head 3 and the stage 2.

[0077] In the above embodiment, the processing vessel 1 has the shower head 3 as an example of the upper wall, but the disclosed technology is not limited thereto. The upper wall of the processing vessel 1 may be an electrode or a wall surface that does not have the gas ejection holes 3d.

[0078] In the above embodiment, the vacuum processing apparatus 100 is described as using a capacitively coupled plasma (CCP) as an example of a plasma source to process the substrate W, but the plasma source is not limited to this. Examples of plasma sources other than the capacitively coupled plasma include inductively coupled plasma (ICP), microwave excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon wave excited plasma (HWP).

[0079] In the above embodiment, the vacuum processing apparatus 100 that performs film formation has been described as an example, but the disclosed technology is not limited to this. That is, the disclosed technology can be applied to other vacuum processing apparatuses such as an etching apparatus or a heating apparatus as long as the vacuum processing apparatus processes the substrate W in a reduced pressure environment.

[0080] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0081] G Gate Valve La Optical axis O center OF standard shape W substrate 100 Vacuum processing equipment 101 Main unit 102 Control section 1 Processing vessel 1a opening 1b Bottom wall 1b1 Recess 1b2 spherical bearing 1c opening 1d Insulating material 1e Window 1F Side wall 2 Stage 2a Support member 2b Heater 2c position 2d bottom end 2e area 2f Convex part 2g Concave 20 Through hole 3. Shower head 3a Tabletop 3b Shower plate 3c Gas diffusion chamber 3d Gas outlet hole 3e Gas inlet 3f position 30 RF power supply 31 Matching box 35 Gas Supply Section 36 Piping 40 Exhaust port 41 Piping 42 Exhaust system 7 Tilt change section 70 Absorption Mechanism 70a opening 71 Bellows 72 Actuator 73 Base material 73a opening 700 Plate members 701 Link material 702 Convex 703 Recess 704 Spherical Bearing 705 Convex 8 Rotating Part 80 Rotation axis 81 Vacuum seal 82 Motor 83 Slip Ring 9 Distance measurement section

Claims

1. a processing vessel having an upper wall, a bottom wall, and a side wall, the interior of which can be maintained at a vacuum atmosphere; a stage provided within the processing vessel on which a substrate is placed, the stage holding the substrate facing the upper wall; a support member that penetrates the bottom wall of the processing vessel and supports the stage from below; a tilt changing unit provided at an end of the support member located outside the processing vessel and configured to change a tilt of the stage with respect to the upper wall of the processing vessel; a distance measuring unit that measures a distance between the upper wall and the stage at a measurement position on a surface of the upper wall that faces the stage; a control unit that controls the tilt changing unit based on the distance between the upper wall and the stage measured by the distance measuring unit so that the upper wall and the stage become parallel to each other; A rotating unit that rotates the stage; Equipped with the distance measurement unit is provided below the stage, irradiates light toward the measurement position, and measures a distance between the distance measurement unit and the object based on the irradiated light and light reflected and received from an object on an optical axis of the light; A vacuum processing apparatus, wherein the stage has a through hole formed therein.

2. the distance measurement units are provided corresponding to the three or more measurement positions, one for each; The control unit is The vacuum processing apparatus according to claim 1 , wherein the tilt changing unit is controlled so that the upper wall and the stage are parallel to each other based on the distance between the upper wall and the stage measured by each of the distance measuring units.

3. The control unit is controlling the rotation unit so that the stage rotates until the position of the through-hole of the stage is at an angle at which the light irradiated along the optical axis passes through the through-hole, and then causing the distance measurement unit to measure a first distance between the distance measurement unit and the upper wall; After controlling the rotation unit so that the stage rotates to an angle at which the stage blocks light irradiated along the optical axis, the distance measurement unit is caused to measure a second distance between the distance measurement unit and a lower surface of the stage; The vacuum processing apparatus according to claim 1 , wherein the distance between the upper wall and the stage is calculated based on a difference between the first distance and the second distance.

4. The vacuum processing apparatus according to claim 3 , wherein the through hole is formed in an area of ​​the stage outside an area on which the substrate is placed.

5. the distance measurement unit is provided at each of the three or more measurement positions, 5 . The vacuum processing apparatus according to claim 3 , wherein the distance measuring units are disposed at equal intervals along an outer periphery of the stage when viewed from a direction intersecting a surface of the upper wall.

6. The number of the through holes is the same as the number of the distance measurement units, The vacuum processing apparatus according to claim 5 , wherein the plurality of through holes are arranged at equal intervals along an outer periphery of the stage.

7. a plate member is connected to the bottom wall of the processing vessel via a link member that absorbs deformation of the bottom wall, the tilt change unit changes the tilt of the stage based on the plate member; The vacuum processing apparatus according to claim 1 , wherein the distance measuring unit is fixed to the plate member.

8. The control unit is 8. A vacuum processing apparatus according to claim 1, wherein the distance measuring unit is caused to measure the distance between the upper wall and the stage after the substrate is placed on the stage, the pressure in the processing vessel is adjusted to a pressure used in processing the substrate, and the temperature of the substrate is adjusted to a temperature used in processing the substrate.

9. The control unit is The vacuum processing apparatus according to claim 1 , wherein the distance measuring unit measures the distance between the upper wall and the stage for each measurement position after cleaning of the inside of the processing vessel is performed.

10. a first rotation step of rotating the stage until a position of a through hole formed in a stage on which a substrate is placed is at an angle at which light irradiated along an optical axis from a distance measurement unit provided below the stage passes through the through hole; a first measuring step of measuring a first distance between the distance measuring unit and the upper wall based on light irradiated from the distance measuring unit along the optical axis to the upper wall of the processing vessel and light received by the distance measuring unit; a second rotation step of rotating the stage along the optical axis until the stage reaches an angle at which the stage blocks light irradiated from the distance measurement unit; a second measuring step of measuring a second distance between the distance measurement unit and a lower surface of the stage based on light irradiated from the distance measurement unit along the optical axis and light received by the distance measurement unit; a changing step of calculating a distance between the upper wall and the stage based on a difference between the first distance and the second distance, and changing an inclination of the stage with respect to the upper wall based on the calculated distance so that the upper wall and the stage become parallel to each other; A tilt adjustment method including:

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