Dispersion plate and plasma processing apparatus

Abstract

To provide a technique capable of enhancing supply efficiency of radicals.SOLUTION: According to an aspect of the present disclosure, there is provided a dispersion plate that partitions a processing container of a plasma processing apparatus into a plasma space and a processing space, the dispersion plate including a first surface having a plurality of first openings that open to one of the plasma space and the processing space, and a second surface having a plurality of second openings that open to the other of the plasma space and the processing space, wherein an opening diameter of the first openings is smaller than an opening diameter of the second openings. At least some of the plurality of second openings communicate with two or more of the first openings via a gas flow path, and the gas flow path increases in diameter from the first opening toward the second opening.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a dispersion plate and a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses that a plate member having a plurality of through holes for trapping ions in plasma is disposed directly below the shower plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-203155 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can increase the supply efficiency of radicals. [Means for solving the problem]

[0005] A dispersion plate according to one aspect of the present disclosure is a dispersion plate that divides the inside of a processing vessel of a plasma processing apparatus into a plasma space and a processing space, and has a first surface on which a plurality of first openings that open into one of the plasma space and the processing space are formed, and a second surface on which a plurality of second openings that open into the other of the plasma space and the processing space are formed, wherein the opening diameter of the first openings is smaller than the opening diameter of the second openings, and at least some of the plurality of second openings are connected to two or more of the first openings via gas flow paths, and the gas flow paths expand in diameter from the first openings toward the second openings. [Effects of the Invention]

[0006] According to the present disclosure, the supply efficiency of radicals can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional perspective view showing a plasma processing apparatus according to an embodiment; [Figure 2] 2 is a perspective view showing the upper surface of a dispersion plate of the plasma processing apparatus of FIG. 1. FIG. [Figure 3] 2 is a perspective view showing the lower surface of a dispersion plate of the plasma processing apparatus of FIG. 1. FIG. [Figure 4] 2 is a cross-sectional perspective view of a dispersion plate of the plasma processing apparatus of FIG. 1. FIG. [Figure 5] FIG. 1 is a diagram (1) showing a first example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 6] FIG. 2 is a diagram (2) showing a first example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 7] FIG. 3 is a diagram showing a first example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 8] FIG. 1 is a diagram (1) showing a second example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 9] FIG. 2 is a diagram (2) showing a second example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 10] FIG. 3 is a diagram showing a second example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 11] FIG. 1 is a diagram (1) showing a third example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 12] FIG. 10 is a diagram (2) showing a third example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 13] FIG. 3 is a diagram (3) showing a third example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 14] FIG. 10 is a diagram (1) showing a fourth example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 15] FIG. 10 is a diagram (2) showing a fourth example of the arrangement of the first opening, the second opening, and the gas flow path. [Figure 16] FIG. 10 is a diagram (3) showing a fourth example of the arrangement of the first opening, the second opening, and the gas flow path. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] In this specification, deviations in directions such as parallel, right angles, orthogonal, horizontal, vertical, up / down, left / right, etc. are permitted as long as they do not impair the effects of the embodiments. The shape of the corners is not limited to right angles and may be rounded like an arch. Parallel, right angles, orthogonal, horizontal, vertical, circular, and coincident may also include approximately parallel, approximately right angles, approximately orthogonal, approximately horizontal, approximately vertical, approximately circular, and approximately coincident.

[0010] [Plasma Processing Apparatus] A plasma processing apparatus 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a cross-sectional perspective view showing the plasma processing apparatus 1 according to an embodiment. The plasma processing apparatus 1 is configured to perform substrate processing such as film formation processing and etching processing on a substrate W.

[0011] The plasma processing apparatus 1 includes a processing chamber 10, a mounting table 20 disposed in the processing chamber 10, a shower head 30 positioned above the mounting table 20, and a controller 80.

[0012] The processing vessel 10 defines an internal space of the plasma processing apparatus 1. The substrate W is processed in the internal space of the processing vessel 10. The substrate W is, for example, a semiconductor wafer. The processing vessel 10 has a substantially cylindrical shape, and a shower head 30 is disposed at the top inside the processing vessel 10. The processing vessel 10 is made of a metal such as aluminum. The processing vessel 10 is grounded.

[0013] The sidewall of the processing vessel 10 provides a passage 25. The substrate W passes through the passage 25 when being transferred between the inside and outside of the processing vessel 10. The passage 25 can be opened and closed by a gate valve 26. The gate valve 26 is provided along the sidewall of the processing vessel 10.

[0014] The bottom of the processing vessel 10 is provided with an exhaust port 22. The exhaust port 22 is connected to an exhaust device 24 via an exhaust pipe 23. The exhaust device 24 includes a pressure controller having an automatic pressure control valve (not shown) and a vacuum pump such as a turbomolecular pump. Gas inside the processing vessel 10 can be exhausted to the outside by the exhaust device 24 via the exhaust port 22. The processing of the substrate W is performed by controlling the inside of the processing vessel 10 to a vacuum atmosphere.

[0015] The mounting table 20 supports the substrate W thereon. The substrate W is placed on the mounting table 20 in a substantially horizontal state. The mounting table 20 may be supported by a support member 21. The support member 21 extends upward from the bottom of the processing vessel 10. The mounting table 20 and the support member 21 may be made of a dielectric material such as aluminum nitride.

[0016] The showerhead 30 includes an upper electrode 42 and a dispersion plate 100. The upper electrode 42 and the dispersion plate 100 are disposed facing each other above the mounting table 20. The upper electrode 42 and the dispersion plate 100 are made of a metal such as an aluminum alloy, nickel, a nickel alloy, or stainless steel.

[0017] The upper electrode 42 includes a disk-shaped upper shower plate 42D and a disk-shaped support plate 42U that is concave on the plasma space 10u side. The dispersion plate 100 is provided below the upper electrode 42 within the processing vessel 10. The upper shower plate 42D and the dispersion plate 100 are perforated plates and have a shower plate structure that supplies gas through a plurality of holes.

[0018] A plasma space 10u is formed below the support plate 42U with an upper shower plate 42D sandwiched therebetween. The space defined by the support plate 42U and the upper shower plate 42D functions as a gas diffusion chamber 43.

[0019] The lower surface of the upper shower plate 42D may have a convex shape, etc. Alternatively, a thin dielectric plate may be formed directly below the upper shower plate 42D, and may be deformed (deflected) by an external force to change the gap between the upper shower plate 42D and the metal surface of the upper shower plate 42D, thereby controlling the plasma.

[0020] High frequency power in the VHF band is supplied to the upper electrode 42 from a high frequency power supply 50 via a matching box 51 and a power transmission line 54. High frequency power in the VHF band is also referred to as VHF power. The dispersion plate 100 has a lower shower plate 110. On the opposite side of the lower shower plate 110 from the plasma space 10u, a processing space 10s is formed between the lower shower plate 110 and the mounting table 20. VHF power is supplied to the plasma space 10u between the upper electrode 42 and the dispersion plate 100, and a gas, which will be described later, is also supplied thereto. The plasma processing apparatus 1 is a remote-type plasma processing apparatus that generates plasma from a gas in the plasma space 10u and supplies active species in the plasma, such as radicals and ions, from the plasma space 10u to the processing space 10s.

[0021] The power transmission line 54 passes through a through hole 27 formed in the ceiling wall 10a of the processing chamber 10 and is connected to the upper electrode 42. In this embodiment, the frequency of the high frequency power supplied from the high frequency power supply 50 is a VHF band frequency, which is 30 MHz to 300 MHz. However, the frequency of the high frequency power supplied from the high frequency power supply 50 is not limited to this, and may be, for example, a UHF band frequency or an RF wave frequency of 13 MHz or higher. The frequency of the UHF wave is 300 MHz to 3 GHz.

[0022] The lower shower plate 110 faces the upper shower plate 42D below the upper shower plate 42D. The diameter of the lower shower plate 110 is larger than the diameter of the upper shower plate 42D and is equal to the diameter of the processing vessel 10. The outer periphery of the lower shower plate 110 is sandwiched and fixed to the sidewall of the processing vessel 10 between the upper and lower parts of the processing vessel 10. In this way, the lower shower plate 110 divides the interior of the processing vessel 10 into an upper space 12 in which the shower head 30 is provided and a lower space 11 in which the mounting table 20 is provided.

[0023] A waveguide 53 is formed along the outer periphery of the support plate 42U between the ceiling wall 10a and the support plate 42U. The waveguide 53 further extends vertically between the sidewall of the processing vessel 10 and the support plate 42U, and extends to the outer periphery of the lower shower plate 110. An annular dielectric radiator 44 is disposed between the upper shower plate 42D and the lower shower plate 110. The diameter of the outer periphery of the radiator 44 is equal to the diameter of the upper shower plate 42D. The radiator 44 transmits the VHF power propagated through the waveguide 53 and radiates it into the plasma space 10u.

[0024] The upper shower plate 42D is provided with a plurality of through-holes 42a that vertically penetrate the upper electrode 42. A source gas is supplied from a source gas supply source 60 through a gas supply line 61, through through-holes 65 that penetrate the ceiling wall 10a, an annular member 66 that connects the ceiling wall 10a and the support plate 42U, and through-holes 67 that penetrate the support plate 42U, to the gas diffusion chamber 43. The source gas is released into the plasma space 10u from the plurality of through-holes 42a in the upper shower plate 42D that communicate with the gas diffusion chamber 43. A reactant gas is supplied from a reactant gas supply source 63 through a gas supply line 64, through through-holes 65 that penetrate the ceiling wall 10a, an annular member 66 that connects the ceiling wall 10a and the support plate 42U, and through-holes 67 that penetrate the support plate 42U, to the gas diffusion chamber 43. The reaction gas is discharged from a plurality of through-holes 42a in an upper shower plate 42D, which communicates with the gas diffusion chamber 43, into the plasma space 10u.

[0025] The dispersion plate 100 divides the interior of the processing chamber 10 into a plasma space 10u and a processing space 10s. The dispersion plate 100 has a lower shower plate 110. The lower shower plate 110 has a disk shape with a thickness of, for example, about 12 mm. The dispersion plate 100 has multiple gas holes. The multiple gas holes penetrate the lower shower plate 110 vertically and open to the processing space 10s. Gases supplied to the plasma space 10u and excited by the plasma, as well as active species such as radicals and ions in the plasma, are supplied to the processing space 10s through the multiple gas holes and used for substrate processing. Details of the dispersion plate 100 will be described later.

[0026] For example, when performing a film formation process by atomic layer deposition (ALD), first, a source gas is supplied to the processing space 10s through a plurality of gas holes in the lower shower plate 110. At this time, VHF power is not supplied. As a result, the source gas is chemically adsorbed onto the surface of the substrate W.

[0027] After the source gas is adsorbed onto the substrate W, an inert gas (purge gas) such as N2 gas is supplied into the processing chamber 10 to replace the source gas in the processing chamber 10 with the inert gas. Next, a reactive gas is supplied into the plasma space 10u from the multiple through-holes 42a of the upper shower plate 42D. At this time, VHF power is supplied from the radiation unit 44 to the plasma space 10u, and the reactive gas is converted into plasma in the plasma space 10u. The reactive gas excited by the plasma and active species such as radicals and ions in the plasma are introduced into the processing space 10s from the multiple gas holes. This causes the source gas adsorbed on the substrate W to react with the reactive gas. For example, if the source gas is a silicon-containing gas and the reactive gas is ammonia (NH3) gas, NH3 generated by decomposition of NH3 molecules is introduced into the processing space 10s. x The radicals nitride the silicon-containing gas on the surface of the substrate W, and a silicon nitride film is formed on the substrate W.

[0028] The control unit 80 is an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), etc. The control unit 80 executes various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0029] [Dispersion plate] 2 to 4, the dispersion plate 100 included in the plasma processing apparatus 1 will be described. Fig. 2 is a perspective view showing the upper surface of the dispersion plate 100 of the plasma processing apparatus 1 of Fig. 1. Fig. 3 is a perspective view showing the lower surface of the dispersion plate 100 of the plasma processing apparatus 1 of Fig. 1. Fig. 4 is a cross-sectional perspective view of the dispersion plate 100 of the plasma processing apparatus 1 of Fig. 1.

[0030] The dispersion plate 100 has a lower shower plate 110 , a first opening 111 , a second opening 112 , a gas flow path 113 , and a slit 114 .

[0031] The lower shower plate 110 has an upper surface 110a and a lower surface 110b. The upper surface 110a is exposed to the plasma space 10u. The lower surface 110b is exposed to the processing space 10s. The upper surface 110a is an example of a first surface, and the lower surface 110b is an example of a second surface.

[0032] A plurality of first openings 111 are provided on the upper surface 110a of the lower shower plate 110. Each of the first openings 111 opens into the plasma space 10u. Each of the first openings 111 has a circular shape in a plan view. The plurality of first openings 111 are arranged, for example, at the vertices of a regular polygon that fills the upper surface 110a of the lower shower plate 110. The regular polygon is, for example, an equilateral triangle. The regular polygon may be a square or a regular hexagon.

[0033] A plurality of second openings 112 are provided on the lower surface 110b of the lower shower plate 110. Each second opening 112 opens into the processing space 10s. Each second opening 112 has a circular shape in a plan view. The number of second openings 112 is, for example, smaller than the number of first openings 111. The plurality of second openings 112 are arranged, for example, at the vertices of a regular polygon that fills the lower surface 110b of the lower shower plate 110. The regular polygon is, for example, an equilateral triangle. The regular polygon may be a square or a regular hexagon.

[0034] A plurality of gas flow paths 113 are provided inside the lower shower plate 110. Each gas flow path 113 connects two or more first openings 111 and one second opening 112. Each gas flow path 113 joins gases and activated species flowing in from two or more first openings 111 and flows out to one second opening 112. Each gas flow path 113 expands in diameter from the first opening 111 toward the second opening 112. In this case, the conductance of the flow path formed in the lower shower plate 110 and connecting the plasma space 10u and the processing space 10s can be increased. This increases the supply efficiency of gases, activated species, and the like supplied from the plasma space 10u to the processing space 10s.

[0035] The diameter of each first opening 111 may be smaller than the diameter of each second opening 112. In this case, radicals can be efficiently supplied to the processing space 10s in response to ions in the plasma generated in the plasma space 10u. That is, the radical supply efficiency can be increased. Furthermore, the discharge stability of the plasma in the plasma space 10u is improved when high-frequency power in the VHF band is supplied to the upper electrode 42. The diameter of each first opening 111 is, for example, 2 mm or less. In this case, even when the frequency of the high-frequency power supplied to the upper electrode 42 is particularly high, for example, 180 MHz or higher, the discharge stability of the plasma in the plasma space 10u is improved. The diameter of each second opening 112 is, for example, 12 mm.

[0036] The slits 114 penetrate the lower shower plate 110 in the thickness direction. The slits 114 are formed, for example, from the center O of the lower shower plate 110 toward the outer periphery. The slits 114 are formed, for example, radially from the center O of the lower shower plate 110. The slits 114 may branch into multiple slits midway from the center O toward the outer periphery of the lower shower plate 110. The slits 114 penetrate the lower shower plate 110 in the thickness direction, crossing the multiple first openings 111 so as to connect the multiple first openings 111 provided in the upper surface 110a of the lower shower plate 110. The slits 114 are formed, for example, to connect the centers of the multiple first openings 111. The slits 114 connecting the multiple first openings 111 have, for example, the same width. The slits 114 penetrate the lower shower plate 110 in the thickness direction, crossing the multiple second openings 112 so as to connect the multiple second openings 112 provided in the lower surface of the lower shower plate 110. The slits 114 are formed, for example, so as to connect the centers of the second openings 112. The slits 114 connecting the plurality of second openings 112 have, for example, the same width.

[0037] By providing the slits 114 in the lower shower plate 110, stress due to the difference in expansion between the central portion, which is likely to be hotter, and the peripheral portion, which is likely to be colder, is less likely to occur depending on the temperature distribution of the dispersion plate 100. This alleviates the stress generated in the lower shower plate 110 when the lower shower plate 110 receives heat from a heater or plasma, and reduces the thermal stress of the dispersion plate 100. This makes it possible to suppress vertical deformation of the dispersion plate 100. Furthermore, as the temperature increases, the dispersion plate 100 expands in a direction that narrows the slits 114. Therefore, in an actual usage environment, the gap of the slits 114 becomes narrower, and the influence of the slits 114 on other things, such as the distribution of the reaction gas supplied from the plasma space 10u to the processing space 10s, can be reduced.

[0038] The dispersion plate 100 is a single object manufactured by, for example, three-dimensional additive manufacturing. In this case, the first opening 111, the second opening 112, the gas flow path 113, and the slits 114 can be manufactured simultaneously, thereby reducing the time required for manufacturing. The dispersion plate 100 may also be formed by cutting or casting.

[0039] (Example 1) 5 to 7, a first example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100 will be described. FIGS. 5 to 7 are diagrams showing a first example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100. FIGS. 5 to 7 show a partial area of ​​the dispersion plate 100. FIG. 5 is a plan view. FIG. 6 is a perspective view of the dispersion plate 100 when viewed from the first opening 111 side. FIG. 7 is a perspective view of the dispersion plate 100 when viewed from the second opening 112 side. In FIGS. 6 and 7, the lower shower plate 110 is not shown (the first openings 111, the second openings 112, and the gas flow paths 113 are shown as concrete objects).

[0040] In a first example, the multiple first openings 111 are periodically arranged in the first direction at a pitch P1, and the multiple second openings 112 are periodically arranged in the first direction at a pitch P2. The pitch P2 is twice the pitch P1. The pitch P1 is an example of the first pitch, and the pitch P2 is an example of the second pitch.

[0041] The plurality of first openings 111 are arranged at the vertices of an equilateral triangle X1 that is tessellated on the upper surface 110a of the lower shower plate 110. The length of one side of the equilateral triangle X1 is equal to a pitch P1. The plurality of second openings 112 are arranged at the vertices of an equilateral triangle Y1 that is tessellated on the lower surface 110b of the lower shower plate 110. The length of one side of the equilateral triangle Y1 is equal to a pitch P2. The length of one side of the equilateral triangle Y1 is twice the length of one side of the equilateral triangle X1.

[0042] Each second opening 112 communicates with seven first openings 111 via a gas flow path 113. The central axis of one of the seven first openings 111 coincides with the central axis of the second opening 112. In a plan view, the remaining six of the seven first openings 111 are arranged around the central axis of the second opening 112.

[0043] The plurality of first openings 111 may include a first opening 111a that communicates with one second opening 112 and a first opening 111b that communicates with two or more second openings 112.

[0044] The diameter of each first opening 111 is smaller than the diameter of each second opening 112. The diameter of each gas flow passage 113 increases from the first opening 111 toward the second opening 112.

[0045] (Example 2) 8 to 10, a second example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100 will be described. FIGS. 8 to 10 are diagrams showing a second example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100. FIGS. 8 to 10 show a partial area of ​​the dispersion plate 100. FIG. 8 is a plan view. FIG. 9 is a perspective view of the dispersion plate 100 when viewed from the first opening 111 side. FIG. 10 is a perspective view of the dispersion plate 100 when viewed from the second opening 112 side. In FIGS. 9 and 10, the lower shower plate 110 is not shown (the first openings 111, the second openings 112, and the gas flow paths 113 are shown as concrete objects).

[0046] In the second example, the multiple first openings 111 are periodically arranged in the first direction at a pitch P3, and the multiple second openings 112 are periodically arranged in the first direction at a pitch P4. The pitch P4 is twice the pitch P4. The pitch P3 is an example of the first pitch, and the pitch P4 is an example of the second pitch.

[0047] The plurality of first openings 111 are arranged at the vertices of squares X2 that are tessellated on the upper surface 110a of the lower shower plate 110. The length of one side of the squares X2 is a pitch P3. The plurality of second openings 112 are arranged at the vertices of squares Y2 that are tessellated on the lower surface 110b of the lower shower plate 110. The length of one side of the squares Y2 is a pitch P4. The length of one side of the squares Y2 is twice the length of one side of the squares X2.

[0048] Each second opening 112 communicates with nine first openings 111 via a gas flow path 113. The central axis of one of the nine first openings 111 coincides with the central axis of the second opening 112. In a plan view, the remaining eight first openings 111 of the nine first openings 111 are arranged around the central axis of the second opening 112.

[0049] The plurality of first openings 111 may include a first opening 111a that communicates with one second opening 112 and a first opening 111b that communicates with two or more second openings 112.

[0050] The diameter of each first opening 111 is smaller than the diameter of each second opening 112. The diameter of each gas flow passage 113 increases from the first opening 111 toward the second opening 112.

[0051] (Example 3) 11 to 13, a third example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100 will be described. FIGS. 11 to 13 are diagrams showing the third example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100. FIGS. 11 to 13 show a partial area of ​​the dispersion plate 100. FIG. 11 is a plan view. FIG. 12 is a perspective view of the dispersion plate 100 when viewed from the first opening 111 side. FIG. 13 is a perspective view of the dispersion plate 100 when viewed from the second opening 112 side. In FIGS. 12 and 13, the lower shower plate 110 is not shown (the first openings 111, the second openings 112, and the gas flow paths 113 are shown as concrete objects).

[0052] In the third example, the first openings 111 are periodically arranged in the first direction at a pitch P5, and the second openings 112 are periodically arranged in the first direction at a pitch P6. The pitch P6 is twice the pitch P5. The pitch P5 is an example of the first pitch, and the pitch P6 is an example of the second pitch.

[0053] The plurality of first openings 111 are arranged at the vertices of an equilateral triangle X3 that is tessellated on the upper surface 110a of the lower shower plate 110. The length of one side of the equilateral triangle X3 is equal to a pitch P5. The plurality of second openings 112 are arranged at the vertices of an equilateral triangle Y3 that is tessellated on the lower surface 110b of the lower shower plate 110. The length of one side of the equilateral triangle Y3 is equal to a pitch P6. The length of one side of the equilateral triangle Y3 is twice the length of one side of the equilateral triangle X3.

[0054] Each second opening 112 communicates with six first openings 111 via a gas flow path 113. The central axis of each second opening 112 does not coincide with the central axis of any of the multiple first openings 111. In a plan view, the six first openings 111 are arranged around the central axis of the second opening 112.

[0055] The plurality of first openings 111 may include a first opening 111a that communicates with one second opening 112 and a first opening 111b that communicates with two or more second openings 112.

[0056] The diameter of each first opening 111 is smaller than the diameter of each second opening 112. The diameter of each gas flow passage 113 increases from the first opening 111 toward the second opening 112.

[0057] (Example 4) 14 to 16, a fourth example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100 will be described. FIGS. 14 to 16 are diagrams showing the fourth example of the arrangement of the first openings 111, the second openings 112, and the gas flow paths 113 of the dispersion plate 100. FIGS. 14 to 16 show a partial area of ​​the dispersion plate 100. FIG. 14 is a plan view. FIG. 15 is a perspective view of the dispersion plate 100 when viewed from the first opening 111 side. FIG. 16 is a perspective view of the dispersion plate 100 when viewed from the second opening 112 side. In FIGS. 15 and 16, the lower shower plate 110 is not shown (the first openings 111, the second openings 112, and the gas flow paths 113 are shown as actual objects).

[0058] In the fourth example, the first openings 111 are periodically arranged in the first direction at a pitch P7, and the second openings 112 are periodically arranged in the first direction at a pitch P8. The pitch P8 is twice the pitch P7. The pitch P7 is an example of the first pitch, and the pitch P8 is an example of the second pitch.

[0059] The plurality of first openings 111 are arranged at the vertices of squares X4 that are tessellated on the upper surface 110a of the lower shower plate 110. The length of one side of the squares X4 is a pitch P7. The plurality of second openings 112 are arranged at the vertices of squares Y4 that are tessellated on the lower surface 110b of the lower shower plate 110. The length of one side of the squares Y4 is a pitch P8. The length of one side of the squares Y4 is twice the length of one side of the squares X4.

[0060] Each second opening 112 communicates with four first openings 111 via a gas flow path 113. The central axis of each second opening 112 does not coincide with the central axis of any of the multiple first openings 111. In a plan view, the four first openings 111 are arranged around the central axis of the second opening 112.

[0061] The plurality of first openings 111 may include a first opening 111 a that communicates with one second opening 112 .

[0062] The opening diameter of each first opening 111 is smaller than the opening diameter of each second opening 112. Each gas flow path 113 expands in diameter from the first opening 111 toward the second opening 112. Each gas flow path 113 communicates with the first opening 111 and the second opening 112 without branching.

[0063] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0064] In the above embodiment, the case where the plurality of first openings 111 are provided in the upper surface 110a of the lower shower plate 110 and the plurality of second openings 112 are provided in the lower surface 110b of the lower shower plate 110 has been described, but the present disclosure is not limited to this. For example, the plurality of first openings 111 may be provided in the lower surface 110b of the lower shower plate 110 and the plurality of second openings 112 may be provided in the upper surface 110a of the lower shower plate 110. Even in this case, radicals can be efficiently supplied to the processing space 10s in response to ions in the plasma generated in the plasma space 10u. In other words, the supply efficiency of radicals can be improved.

[0065] In the above embodiment, the plasma processing apparatus is described as a premix type apparatus in which the source gas and the reactive gas are mixed before being supplied to the gas diffusion chamber, but the present disclosure is not limited thereto. For example, the plasma processing apparatus may be a postmix type apparatus in which the source gas and the reactive gas are not mixed before being supplied to the gas diffusion chamber. For example, the source gas may be supplied from a source gas supply source through a gas supply line into a flow path formed in a distribution plate, and then supplied to the processing space through multiple gas holes provided at the bottom of the flow path. [Explanation of symbols]

[0066] 1. Plasma processing equipment 10 Processing container 10u plasma space 10s processing space 100 Dispersion plate 110 Lower shower plate 110a top side 110b Bottom side 111 First Opening 112 Second Opening 113 Gas flow path

Claims

1. A dispersion plate that divides the inside of a processing chamber of a plasma processing apparatus into a plasma space and a processing space, a first surface having a plurality of first openings formed therein, the first openings opening into one of the plasma space and the processing space; a second surface having a plurality of second openings formed therein, the second openings opening into the other of the plasma space and the processing space; and The diameter of the first opening is smaller than the diameter of the second opening, At least some of the second openings communicate with two or more of the first openings via gas flow paths; The gas flow path expands in diameter from the first opening toward the second opening. Dispersion plate.

2. the plurality of first openings are open to the plasma space, the second openings are open to the processing space; The dispersion plate of claim 1 .

3. a central axis of each of the plurality of second openings coincides with a central axis of any of the plurality of first openings; The dispersion plate of claim 1 .

4. a central axis of each of the second openings does not coincide with a central axis of any of the first openings; The dispersion plate of claim 1 .

5. the plurality of first openings are periodically arranged at a first pitch; the plurality of second openings are periodically arranged at a second pitch that is twice the first pitch; The dispersion plate of claim 1 .

6. The opening diameter of the first opening is 2 mm or less. A dispersion plate according to any one of claims 1 to 5.

7. The dispersion plate has a slit penetrating in the thickness direction. A dispersion plate according to any one of claims 1 to 5.

8. VHF power is supplied to the plasma space. A dispersion plate according to any one of claims 1 to 5.

9. The dispersion plate is made of an aluminum alloy. A dispersion plate according to any one of claims 1 to 5.

10. a dispersion plate that divides the interior of the processing chamber into a plasma space and a processing space; a mounting table provided opposite the dispersion plate; Equipped with The dispersion plate is a first surface having a plurality of first openings formed therein, the first openings opening into one of the plasma space and the processing space; a second surface having a plurality of second openings formed therein, the second openings opening into the other of the plasma space and the processing space; and The diameter of the first opening is smaller than the diameter of the second opening, At least some of the second openings communicate with two or more of the first openings via gas flow paths; The gas flow path expands in diameter from the first opening toward the second opening. Plasma processing equipment.

Images