Plasma processing apparatus

Abstract

To efficiently activate gas by plasma in the vicinity of a supply port of electromagnetic waves.SOLUTION: A plasma processing device has a processing container, a top wall forming part of the processing container and having an aperture, and a transmission window closing the aperture. The aperture below the transmission window is formed as a recess. The recess is a supply port for supplying electromagnetic waves from the transmission window into the processing container. A first gas supply port is provided on the lower surface of the top wall. A second gas supply port is provided on the inner surface of the recess.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus.

Background Art

[0002] For example, Patent Document 1 discloses a plurality of gas nozzles protruding from the top wall of a processing chamber. The gas nozzles supply a gas that is relatively easy to dissociate at a position below the lower surface of the top wall, and adjust the dissociation of the gas. It is difficult and costly to process the gas nozzles protruding from the top wall.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of efficiently performing gas activation by plasma near a supply port of electromagnetic waves.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, there is provided a plasma processing apparatus including a processing chamber, a top wall that forms a part of the processing chamber and has an opening, and a transmissive window that closes the opening, wherein the opening under the transmissive window is formed as a recess, the recess is a supply port for supplying electromagnetic waves from the transmissive window into the processing chamber, a first gas supply hole is provided on the lower surface of the top wall, and a second gas supply hole is provided on the inner surface of the recess.

Effects of the Invention

[0006] According to one aspect, gas activation by plasma near the supply port of electromagnetic waves can be efficiently performed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0008] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are given to the same components, and duplicate descriptions may be omitted.

[0009] In this specification, in directions such as parallel, right angle, orthogonal, horizontal, vertical, up and down, left and right, etc., a deviation to the extent that the effects of the embodiment are not impaired is allowed. The shape of the corners is not limited to a right angle and may be rounded in an arcuate shape. Parallel, right angle, orthogonal, horizontal, vertical, circle, coincidence may include substantially parallel, substantially right angle, substantially orthogonal, substantially horizontal, substantially vertical, substantially circle, substantially coincidence.

[0010] [Plasma Processing Apparatus] An example of a plasma processing apparatus according to an embodiment will be described. FIG. 1 is a schematic cross-sectional view showing an example of a plasma processing apparatus 100 according to an embodiment. The plasma processing apparatus 100 includes a processing container 101, a mounting table 102, a gas supply unit 103, an exhaust device 104, a microwave radiation source 140, and a control unit 106.

[0011] The processing container 101 is made of a metal material, for example, yttria (Y 2 O 3It is made of aluminum that has been film-treated with etc., and has a bottomed cylindrical container body 112 and a top wall 111. The top wall 111 is provided above the container body 112, and the top wall 111 forms part of the processing container 101. The container body 112 and the top wall 111 form a plasma processing space U. The top wall 111 has an upper surface 111b and a lower surface 111a, and the lower surface 111a is exposed to the plasma processing space U. The top wall 111 has a plurality of openings, and a plurality of microwave radiation sources 140 are arranged on the upper surface 111b side so as to close the plurality of openings.

[0012] Inside the processing container 101, a mounting table 102 is arranged at the bottom. The mounting table 102 is disc-shaped and is formed of a metal material such as aluminum that has been anodized on its surface, or a ceramic material such as aluminum nitride (AlN) for example. The mounting table 102 mounts a substrate W such as a semiconductor wafer as an example. The mounting table 102 is supported by a metal support member 120 that extends upward from the bottom of the container body 112 via an insulating member 121.

[0013] Also, inside the mounting table 102, lifting pins (not shown) for lifting and lowering the substrate W are provided so as to be able to protrude and retract with respect to the upper surface of the mounting table 102. Further, a heater 107 is provided inside the mounting table 102 as heating means. The heater 107 is supplied with power from a heater power supply 127 and generates heat. Then, the temperature of the substrate W is controlled to a predetermined temperature by controlling the output of the heater 107 based on the temperature signal of a sensor (for example, a thermocouple) (not shown) provided near the upper surface of the mounting table 102.

[0014] A high-frequency power supply 122 is electrically connected to the mounting table 102. When the mounting table 102 is made of ceramics, an electrode is provided on the mounting table 102, and the high-frequency power supply 122 is electrically connected to the electrode. The high-frequency power supply 122 applies high-frequency power to the mounting table 102 as bias power. The frequency of the high-frequency power applied by the high-frequency power supply 122 preferably ranges from 0.4 to 27.12 MHz.

[0015] An exhaust pipe 116 is provided at the bottom of the container body 112, and an exhaust device 104 is connected to the exhaust pipe 116. The exhaust device 104 includes a vacuum pump, a pressure control valve, etc. The inside of the processing container 101 is evacuated through the exhaust pipe 116 by the vacuum pump and controlled to a desired vacuum state. The pressure inside the processing container 101 is controlled by a pressure control valve based on the value of a pressure gauge (not shown). An inlet / outlet 114 for carrying the substrate W in and out is provided on the side wall of the container body 112 between the processing container 101 and an adjacent transfer chamber (not shown). When the substrate W is carried in and out, the inlet / outlet 114 is opened by a gate valve 115 provided along the side wall of the container body 112.

[0016] The microwave radiation sources 140 are arranged at six openings (only two are shown in FIG. 1) in the outer peripheral region of the top wall 111 and one opening in the central region of the top wall 111. In this embodiment, the transmission windows 145 at the lower ends of each of the seven microwave radiation sources 140 close the openings of the top wall 111, whereby the entire microwave radiation sources 140 are installed on the upper surface 111b of the top wall 111. However, the number and arrangement of the microwave radiation sources 140 are not limited to this. For example, only one may be arranged in the central region of the top wall 111, or a plurality may be arranged only in the outer peripheral region of the top wall 111.

[0017] The microwave radiation sources 140 are connected to the microwave output section 130 via the amplifier sections 142. The microwave output section 130 generates microwaves and distributes the microwaves to output them to each amplifier section 142. Each amplifier section 142 mainly amplifies the distributed microwaves and outputs them to each microwave radiation source 140.

[0018] The microwave radiation source 140 has an antenna module 143, a slot antenna 144, and a transmission window 145. The antenna module 143 is a coaxial waveguide having an inner conductor 143a and an outer conductor 143b arranged concentrically around the inner conductor 143a, and microwaves propagate in the space between the inner conductor 143a and the outer conductor 143b. Annular dielectric members M1 and M2 are provided in the space between the inner conductor 143a and the outer conductor 143b. The dielectric member M1 is disposed above the dielectric member M2. The dielectric members M1 and M2 are vertically movable to adjust the impedance.

[0019] The tip of the outer conductor 143b (the tip of the antenna module 143) has an enlarged diameter. A disk-shaped slot antenna 144 is fitted inside the enlarged diameter of the outer conductor 143b. The antenna module 143 and the slot antenna 144 are provided above (outside) the top wall 111. The inner conductor 143a abuts against the center of the upper surface of the slot antenna 144. The slot antenna 144 has an arc-shaped or annular slot S around the center of the slot antenna 144. The slot antenna 144 has the function of an antenna that radiates microwaves from the slot S.

[0020] Below the slot antenna 144, a transmission window 145 for radiating the microwaves radiated from the slot S into the processing container 101 is provided. The transmission window 145 is formed of a dielectric such as alumina (Al 2 O 3 ) and transmits microwaves. The transmission window 145 closes the opening at the upper position of the opening provided in the top wall 111. Thereby, the opening under the transmission window 145 is formed as a recess V. The recess V functions as a supply port for supplying microwaves, which are an example of electromagnetic waves, to the plasma processing space U. The microwaves transmitted through the transmission window 145 are radiated from the supply port of the recess V into the plasma processing space U in the processing container 101.

[0021] The gas supply unit 103 includes a plurality of gas introduction pipes 124 to 126, a gas supply pipe 128, and a gas supply source 129. The plurality of gas introduction pipes 124 to 126 are connected to the gas supply source 129 via the gas supply pipe 128. The plurality of gas introduction pipes 124 to 126 supply gas around the microwave radiation source 140 in the central region of the top wall 111.

[0022] The plurality of gas introduction pipes 124 and 125 are respectively connected to first gas supply paths R1 and R2 configured to penetrate the top wall 111 in the vertical direction. The first gas supply path R1 has a first gas supply hole 124a that opens to the lower surface 111a, and the first gas supply path R2 has a first gas supply hole 125a that opens to the lower surface 111a (see Fig. 3(a)).

[0023] The plurality of gas introduction pipes 126 are connected to a second gas supply path R3 including a path 126b extending from above the top wall 111 (see Fig. 3(a)) and a path 126c that bends horizontally within the top wall 111 and extends to the inner surface 111c of the recess V. The second gas supply path R3 has a second gas supply hole 126a that opens to the inner surface 111c.

[0024] The gas supply source 129 supplies a processing gas. As an example, when forming a silicon nitride film (SiN) on the substrate W, N 2 gas and / or NH 3 gas are supplied from the plurality of first gas supply holes 124a, and SiH 4 (silane) gas is supplied from the plurality of first gas supply holes 125a. Also, N 2 gas and / or NH 3 gas are supplied from the plurality of second gas supply holes 126a.

[0025] However, the supply of the processing gas is not limited to this. The first gas supply hole 125a may supply a gas that is relatively easy to decompose, and the second gas supply hole 126a may supply a gas that is relatively difficult to decompose. Note that the first gas supply hole 124a may supply a gas that is relatively easy to decompose or a gas that is relatively difficult to decompose.

[0026] In addition, the gas supply pipe 128 is provided with a valve for controlling the supply and stop of the processing gas and a flow regulator for adjusting the flow rate of the processing gas.

[0027] The control unit 106 is, for example, a computer having a controller 106a and a memory 106b. The control unit 106 may have an input device, a display device, etc. The controller 106a controls each part of the plasma processing apparatus 100. With the controller 106a, an operator can perform input operations of commands and the like for managing the plasma processing apparatus 100 using an input device. Further, the controller 106a can visualize and display the operating status and the like of the plasma processing apparatus 100 on a display device. Furthermore, the memory 106b stores a control program and recipe data for controlling various processes executed in the plasma processing apparatus 100 by the controller 106a. By the controller 106a executing the control program and controlling each part of the plasma processing apparatus 100 according to the recipe data, processing of a substrate such as film formation is executed using the plasma processing apparatus 100.

[0028] [Gas supply mechanism] Next, the details of the gas supply structure near the supply port for supplying microwaves will be described with reference to FIGS. 2 and 3. FIG. 2(a) is a diagram showing an example of the gas supply structure according to the reference example. FIG. 3(a) is a diagram showing an example of the gas supply structure according to the embodiment.

[0029] In the reference example of FIG. 2(a), a recess V' is formed under the transmission window 145'. The recess V' serves as a supply port for supplying the microwaves radiated from the transmission window 145' into the processing container 101. The depth of the recess V' is indicated by H4. In other words, the length of the inner surface 111c of the recess V' is H4. When supplying gases A and B, the gas introduction pipe 123 is configured to supply the gas B that is relatively easy to decompose from the gas supply hole 123a, and the gas introduction pipe 124 is configured to supply the gas A that is relatively difficult to decompose from the gas supply hole 124a. As an example, the processing gas B is SiH 4 gas, and the processing gas A is N 2Gas and / or NH 3 Use this as the gas. In the reference example, SiH which is relatively easy to decompose 4 The gas (gas B) is supplied into the processing container 101 from a plurality of gas nozzles 111d protruding from the lower surface 111a of the top wall 111. The length of the gas nozzle 111d from the lower surface 111a of the top wall 111 is denoted as H3.

[0030] The transmission window 145' is disk-shaped and closes the opening from the upper surface 111b side of the opening in the top wall 111. An O-ring 146 is provided at the boundary between the transmission window 145' and the top wall 111. The O-ring 146 seals the inside of the processing container 101 from the atmosphere outside the processing container 101 and maintains the airtightness inside the processing container 101.

[0031] The first gas supply hole 124a supplies N 2 Gas and / or NH 3 The gas into the processing container 101. The gas supply hole 123a supplies SiH 4 The gas from the tip of the gas nozzle 111d.

[0032] FIG. 2(b) is a view of the vicinity of the recess V' under the transmission window 145' as seen from the lower surface 111a side of the top wall 111. As shown in FIG. 2(b), the first gas supply hole 124a is arranged on the same circumference as the gas supply hole 123a provided in the gas nozzle 111d, and the gas supply hole 123a and the first gas supply hole 124a are provided alternately. In FIG. 2(a), for the sake of convenience, the positions of the first gas supply hole 124a and the gas supply hole 123a are shown shifted in the radial direction.

[0033] N 2 Gas and / or NH 3 The gas is activated by the plasma generated in the processing container 101 including the vicinity of the recess V' to make it easier to react. In the vicinity of the recess V', a high-density plasma region is formed by the activated N 2 Gas and / or NH 3 Gas. Therefore, if the supply position of the SiH 4 Gas is close to the region of the recess V', the highly reactive SiH 4Gas may polymerize in the gas phase and fly onto the substrate W to become particles. Also, abnormal discharge may occur at the gas supply hole 123a for supplying SiH 4 gas.

[0034] Therefore, in the reference example, the gas supply hole 123a is provided at a position lower by the length H3 than the height at which the first gas supply hole 124a for N 4 gas, NH 2 gas is provided, and SiH 3 gas is supplied from the gas supply hole 123a away from the high-density plasma region. Thereby, the activated N 4 gas and / or NH 2 gas are reacted to nitride Si resulting from SiH 3 gas, and a silicon nitride film is formed on the substrate W. Thereby, the generation of particles is suppressed, and abnormal discharge at the gas supply hole 123a of SiH 4 gas is suppressed. 4

[0035] However, in the reference example, by forming the protrusion of the gas nozzle 111d downward from the lower surface 111a of the top wall 111, the shape of the top wall 111 becomes complicated, the processing difficulty increases, and the cost becomes high. In addition, since the top wall 111 is formed of aluminum, a sprayed film such as yttria is sprayed on the top wall 111 to obtain plasma resistance, but due to the protrusion of the gas nozzle 111d during spraying, the processing difficulty of spraying becomes high, and the processing cost and the apparatus cost increase.

[0036] Also, when removing the silicon nitride film adhering to the inner wall of the processing container 101 etc. during cleaning, NF 3 gas is supplied from the gas nozzle 111d. At that time, aluminum fluoride (AlF) and yttrium fluoride (YF), which are by-products generated, adhere to the gas nozzle 111d and cause particles. In addition, due to the protrusion of the gas nozzle 111d, the arrangement of the gas supply holes may be restricted, which may hinder a free design.

[0037] Therefore, in the gas supply structure according to the embodiment, as shown in FIG. 3(a), the structure of the gas nozzle 111d is eliminated, and the lower surface 111a of the top wall 111 is positioned downward by, for example, a length H3. That is, the top wall 111 of the embodiment is formed thicker by H3 compared to the top wall 111 of the reference example, and the high-density plasma region is shifted upward by H3. As a result, N 2 gas and / or NH 3 The first gas supply hole 124a for supplying gas and SiH 4 The first gas supply hole 125a for supplying gas are formed on the same surface (lower surface 111a) and on the same circumference. That is, the lower surface 111a of the top wall 111 can be made flat, and the first gas supply hole 124a and the first gas supply hole 125a are provided at the same height. As a result, by simplifying the shape of the top wall 111, the gas supply structure near the microwave supply port can be simply configured, and the processing difficulty can be reduced.

[0038] In the embodiment of FIG. 3(a), a recess V is formed under the transmission window 145. The recess V serves as a supply port for supplying the microwave radiated from the transmission window 145 into the processing container 101. The depth of the recess V becomes deeper by the amount by which the top wall 111 becomes thicker (that is, H3), and the length of the inner surface 111c of the recess V is H4 + H3. The first gas supply hole 125a is configured to supply SiH 4 gas (gas B), and the first gas supply hole 124a is configured to supply N 2 gas and / or NH 3 gas (gas A). However, the supply of N 2 gas and / or NH 3 gas (gas A) that is relatively difficult to decompose from the first gas supply hole 124a is not essential because the second gas supply hole 126a described later is provided.

[0039] FIG. 3(b) is a view of the vicinity of the recess V under the transmission window 145 as seen from the lower surface 111a side of the top wall 111. As shown in FIG. 3(b), the first gas supply hole 125a for supplying SiH 4 gas (gas B) and N 2 gas and / or NH 3A first gas supply hole 124a for supplying a gas (gas A) and a first gas supply hole 125a are provided alternately. The first gas supply hole 125a and the first gas supply hole 124a are provided at equal intervals. For convenience in FIG. 3(a), the first gas supply hole 124a and the first gas supply hole 125a are shown shifted in the radial direction.

[0040] The depth of the concave portion V is deeper than that in the reference example by the length of H3 where the top wall 111 is thickened. Thus, N 2 Gas and / or NH 3 A plurality of second gas supply holes 126a for supplying a gas are arranged at equal intervals on the inner surface 111c of the concave portion V. Thereby, the second gas supply holes 126a can be arranged away from the first gas supply holes 124a and 125a. As a result, abnormal discharge occurs at the first gas supply hole 125a, and highly reactive SiH 4 Gas polymerization in the gas phase to form particles can be prevented or suppressed.

[0041] N 2 Gas and / or NH 3 Gas is directly supplied from the second gas supply hole 126a to the high-density plasma region under the transmission window 145. Thereby, N 2 Gas and / or NH 3 Gas activation can be promoted.

[0042] The transmission window 145 has a downward concave shape and has a thickness in an annular shape on the outer peripheral side. An O-ring 146 is provided at the boundary between the transmission window 145 and the top wall 111. The O-ring 146 seals the inside of the processing container 101 from the atmosphere outside the processing container 101 and maintains the airtightness inside the processing container 101.

[0043] In the embodiment as well, the top wall 111 is coated with a sprayed film such as an Italian sprayed film, and a sprayed film is also formed on the inner wall of the recess V. On the other hand, the lower surface of the transmission window 145 is concave, and the position of the O-ring 146 in the embodiment is lower than that in the reference example by the thickness of the outer periphery of the transmission window 145. As a result, the O-ring 146 can be disposed at a position where the plasma density and temperature are lower than those in the reference example, the consumption of the sprayed film around the O-ring 146 can be alleviated, and the time until the maintenance or replacement of the top wall 111 can be extended.

[0044] From the above, the second gas supply hole 126a is preferably disposed at a position where the consumption of the sprayed film around the O-ring 146 can be alleviated or at a position lower than that and as close as possible to the high-density plasma region below the transmission window 145. Thereby, while alleviating the consumption of the sprayed film in the recess V, the activation of N 2 gas and / or NH 3 gas can be promoted.

[0045] Note that the N 2 gas and / or NH 3 gas supplied from the first gas supply hole 124a dilutes the SiH 4 gas supplied from the first gas supply hole 125a, and has an effect of suppressing the reactivity (decomposition) of the SiH 4 gas. Therefore, the first gas supply holes 124a are preferably alternately arranged on the same circumference as the first gas supply holes 125a. However, as long as particles and abnormal discharges can be suppressed to such an extent that they do not cause problems, the first gas supply holes 124a do not have to be arranged opposite to the first gas supply holes 125a (for example, alternately). For example, the first gas supply holes 124a may be arranged on the inner peripheral side or the outer peripheral side of the first gas supply holes 125a. If the problems of particles and abnormal discharges can be solved, the first gas supply holes 124a may not be provided. According to the gas supply structure according to the embodiment, by eliminating the protrusions from the lower surface 111a of the top wall 111 and making it flat, the degree of freedom in the design of the gas supply holes can be increased.

[0046] [Arrangement of Second Gas Supply Hole] FIG. 4 is a diagram showing an example of the arrangement of gas supply holes according to the embodiment. FIG. 4 is a view of the lower surface 111a of the top wall 111. In FIGS. 4(a) and 4(b), the inside and outside of the boundary line Ar shown as a circle are divided into a central region and an outer peripheral region. In FIGS. 4(a) and 4(b), the top wall 111 has one opening in the central region and six openings in the outer peripheral region, for a total of seven openings, and the seven openings are blocked by seven transmission windows 145. In FIG. 4(a), the second gas supply hole 126a is provided on the inner surface 111c of the recess V under the transmission window 145 that closes the opening in the central region among the seven openings. Around the second gas supply hole 126a, the first gas supply hole 124a and the first gas supply hole 125a are alternately arranged on the same circumference.

[0047] In FIG. 4(b), the second gas supply hole 126a is provided for each of the inner surfaces 111c of the seven recesses V formed under the seven transmission windows 145 that block the seven openings. Around each of the second gas supply holes 126a, the first gas supply hole 124a and the first gas supply hole 125a are alternately arranged on the same circumference.

[0048] However, the arrangement of the gas supply holes in FIG. 4 is an example, and the number and arrangement of the gas supply holes are not limited to this. For example, the number of openings provided in the top wall 111 may be 0 or 1 or more in the central region. The number of openings provided in the top wall 111 may be 0 or a plurality other than six in the outer peripheral region.

[0049] [Direction of the Second Gas Supply Hole] Taking the height direction of the recess V as the Z direction and the plane perpendicular to the Z direction as the XY plane. The Z axis is an axis perpendicular to the lower surface 111a of the top wall 111, and the XY plane is horizontal with respect to the lower surface 111a. As shown in FIGS. 3(b) and 6(a), the axis passing through the center of the transmission window 145 (the center of the recess V) is particularly defined as the Z1 axis.

[0050] FIG. 5 is a diagram showing an example of the angle of the second gas supply hole 126a in the XZ plane. FIG. 6 is a diagram showing an example of the angle of the second gas supply hole 126a in the XY plane.

[0051] Comparing Fig. 5(a) with Fig. 3(a), the second gas supply hole 126a shown in Fig. 3(a) is formed on the XY plane and is orthogonal to the Z direction. Also, as shown in Fig. 3(b), all the plurality of second gas supply holes 126a on the XY plane are directed toward the Z1 axis. That is, the second gas supply hole 126a shown in Figs. 3(a) and 3(b) opens perpendicularly to the inner surface of the recess V.

[0052] In contrast, the second gas supply hole 126a shown in Fig. 5(a) is formed upward from the XY plane and has an angle in the Z direction. As shown in Fig. 5(b), let the angle in the Z direction with respect to the X direction in the XZ plane be θ zx For the second gas supply hole 126a shown in Fig. 5(a), the angle θ zx is greater than 0°, and may be, for example, 30° or more and 45° or less, or 45° or more. The angle θ zx of the second gas supply hole 126a is not limited to this, and it may be formed upward from the XY plane, and an upward angle toward the transmission window 145 is preferable.

[0053] Furthermore, for the second gas supply hole 126a shown in Fig. 5(a), on the XY plane, the second gas supply hole 126a is directed toward the Z1 axis in the same direction as the arrow in Fig. 3(b). That is, the second gas supply hole 126a shown in Fig. 5(a) opens straight without having an inclination in the XY direction with respect to the inner surface of the recess V, and opens at an upward angle θ zx greater than 0° in the Z direction. Note that the angle θ zx does not take a value less than 0°. That is, the second gas supply hole 126a does not open at an angle such that it faces downward with respect to the XY plane.

[0054] In the vicinity directly below the transmission window 145 in the recess V, a higher density plasma is generated. When the second gas supply hole 126a is opened such that the angle θ zx in the Z direction becomes 0° as shown in Fig. 3(a), the N 2 gas and / or NH 3 gas supplied horizontally from the plurality of second gas supply holes 126a arranged on the inner surface 111c are likely to collide with each other inside the recess V. In contrast, as shown in Fig. 5(a), the angle θzx When the second gas supply holes 126a are opened upward so that the angle is greater than 0°, N 2 Gas and / or NH 3 The gas is less likely to collide head-on and flows smoothly up to the vicinity directly below the transmission window 145. This allows the N 2 Gas and / or NH 3 This can promote gas activation.

[0055] 6(a) and 6(b), the second gas supply hole 126a is aligned at an angle θ xy is set to 0°, and the angle θ xy The opening is at an inclination of angle θ xy The angle θ can be either positive or negative. xy When the angle θ is positive, all of the second gas supply holes 126a are opened at the same angle toward the right of the direction toward the Z1 axis. xy When the angle is negative, all of the second gas supply holes 126a open at the same angle toward the left of the direction toward the Z1 axis.

[0056] The angle θ of the second gas supply hole 126a in the Z direction shown in FIGS. zx The angle θ of the second gas supply hole 126a in the Z direction shown in FIGS. zx It is more preferable that the angle is greater than 0°, and the second gas supply holes 126a open obliquely upward to generate a swirling flow.

[0057] In addition, the angle θ zx It is preferable that all of the second gas supply holes 126a have the same angle, but they may have slightly different orientations (angles). xy It is preferable that all of the above be at the same angle, but they may be at slightly different orientations (angles).

[0058] As described above, the second gas supply hole 126a is formed in an oblique direction in the XY plane direction with respect to the direction toward the Z1 axis which is the central axis of the concave portion V, and can be configured to generate a swirling flow in the concave portion V. Thereby, the N 2 gas and / or NH 3 gas becomes a swirling flow and smoothly flows into the high-density plasma region, and a flow of active species can be formed so as to be pushed out from the concave portion V toward the first gas supply holes 124a and 125a sides.

[0059] Thus, by forming a swirling flow of N 2 gas and / or NH 3 gas in the concave portion V, N 2 gas and / or NH 3 gas can be uniformly supplied to the high-density plasma region, and the activation efficiency of N 2 gas and / or NH 3 gas can be increased. In addition, turbulent flow due to the collision of gases in the concave portion V can be avoided, and the efficiency of transporting the activated N 2 gas and / or NH 3 gas toward the first gas supply holes 124a and 125a sides can be increased.

[0060] N 2 gas and / or NH 3 To improve the activation efficiency and transport efficiency of the gas, the angle θ zx of the second gas supply hole 126a is preferably greater than 0, and the angle θ xy has a non-zero positive or negative value. In other words, the second gas supply hole 126a preferably opens in the rightward, leftward, upward, right obliquely upward, or left obliquely upward direction when the horizontal direction toward the Z1 axis is taken as the X direction as a reference.

[0061] As described above, according to plasma processing apparatus 100 of the present embodiment, first gas supply holes 125a are provided in lower surface 111a, and second gas supply holes 126a are provided in inner side surface 111c of recess V. As a result, there are no protrusions on lower surface 111a, the gas supply structure near the electromagnetic wave supply port can be simplified, and the generation of particles and abnormal discharge can be prevented or suppressed.

[0062] [others] The numbers of first gas supply holes 124a, 125a and second gas supply holes 126a may be the same or different.

[0063] N supplied from the first gas supply hole 124a 2 Gas and / or NH 3 gas and N supplied from the second gas supply hole 126a. 2 Gas and / or NH 3 It is preferable to control the N gas independently of the second gas supply hole 126a. 2 Gas and / or NH 3 The gas has a function of generating N radicals and / or NH radicals with high efficiency mainly by high density plasma. 2 Gas and NH 3 The gas is SiH 4 The control unit 106 thus controls the N 2 Gas and / or NH 3 It is preferable to separately control the gases in order to allow them to exert their respective functions, and to optimize the degree of dissociation and the flow rate of the gas supplied from the first gas supply hole 124a and the gas supplied from the second gas supply hole 126a. This makes it possible to more effectively prevent or suppress the generation of particles and abnormal discharge. This also makes it possible to more effectively prevent or suppress the generation of SiH 4 The gas dissociation state can be controlled more accurately, enabling the deposition of high-quality SiN films.

[0064] Therefore, the gas supplied from the first gas supply hole 124a and the gas supplied from the second gas supply hole 126a may have different gas species and / or gas flow rates. For example, NH 3 gas may be introduced from the second gas supply hole 126a to activate (dissociate) the NH 3 gas, and N 2 gas may be introduced from the first gas supply hole 124a to dilute the silane gas with the N 2 gas. Conversely, N 2 gas may be introduced from the second gas supply hole 126a, and NH 3 gas may be introduced from the first gas supply hole 124a. The gas supplied from the first gas supply hole 124a and / or the second gas supply hole 126a may be a gas other than N 2 gas and NH 3 gas, and a gas suitable for each process may be used. Examples include H 2 gas, N 2 O gas, NO gas, O 2 gas, H 2 O gas, and their mixed gases, etc.

[0065] The flow controllers are preferably provided one by one in the central region and one by one in the outer peripheral region for each of the three types of gas supply holes for individually controlling the flow rates of the gases supplied from the three locations of the first gas supply holes 124a, 125a and the second gas supply hole 126a. That is, it is preferable to arrange at least 3 in the central region, 3 in the outer peripheral region, and a total of 6 flow controllers.

[0066] More preferably, three flow controllers are provided for each of the six gas supply structures for the six permeation windows 145 in the outer peripheral region, and one flow controller is provided for each of the one gas supply structures for the one permeation window 145 in the central region. In this case, 3 flow controllers are arranged in the central region, 18 (= 3×6) in the outer peripheral region, and a total of 21 are arranged. By the number and arrangement of the flow controllers, the flow rates of the various gases supplied from the three types of gas supply holes can be controlled more effectively. Therefore, by controlling the activation, transportation, and dilution degrees of the various gases with higher precision, the generation of particles and abnormal discharges can be more effectively prevented or suppressed. Also, thereby, SiH 4The dissociation state of the gas can be more accurately controlled, and a high-quality SiN film can be formed.

[0067] The plasma processing apparatus according to the embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The embodiments can be modified and improved in various forms without departing from the scope and gist of the appended claims. The matters described in the above plurality of embodiments can also adopt other configurations and can be combined within a non-contradictory range.

Explanation of Reference Numerals

[0068] 100 Plasma processing apparatus 101 Processing chamber 102 Stage 103 Gas supply unit 106 Control unit 111 Ceiling 140 Microwave radiation source 144 Slot antenna 145 Transmission window 124a, 125a First gas supply hole 126a Second gas supply hole

Claims

1. A processing container, a top wall that forms part of the processing container and has an opening, a transmissive window that closes the opening, and the opening under the transmissive window is formed as a recess, and the recess is a supply port for supplying electromagnetic waves from the transmissive window into the processing container, a first gas supply hole is provided on the lower surface of the top wall, and a second gas supply hole is provided on the inner surface of the recess, a plasma processing apparatus.

2. The first gas supply hole is configured to supply a gas that is relatively easy to decompose, The second gas supply hole is configured to supply a gas that is relatively difficult to decompose, The plasma processing apparatus according to claim 1.

3. The top wall has a plurality of the openings, a plurality of the transmissive windows close the plurality of the openings, the second gas supply hole is provided on the inner surface of the recess under the transmissive window in the central region among the plurality of the transmissive windows, The plasma processing apparatus according to claim 1 or claim 2.

4. The top wall has a plurality of the openings, a plurality of the transmissive windows close the plurality of the openings, the second gas supply hole is provided on the inner surface of the recess under each of the plurality of the transmissive windows, The plasma processing apparatus according to claim 1 or claim 2.

5. When the height direction of the recess is the Z direction and the plane perpendicular to the Z direction is the XY plane, the second gas supply hole is formed on the XY plane, The plasma processing apparatus according to any one of claims 1 to 4.

6. When the height direction of the recess is the Z direction and the plane perpendicular to the Z direction is the XY plane, the second gas supply hole is formed upward from the XY plane, The plasma processing apparatus according to any one of claims 1 to 4.

7. The second gas supply hole is formed toward the transmissive window, The plasma processing apparatus according to claim 6.

8. The second gas supply hole is formed in an oblique direction with respect to the direction toward the central axis of the recess, The plasma processing apparatus according to any one of claims 5 to 7.

9. The second gas supply hole is configured to generate a swirling flow in the recess, The plasma processing apparatus according to claim 8.

10. The lower surface of the transmissive window is concave, The plasma processing apparatus according to any one of claims 1 to 9.

11. The first gas supply path having the first gas supply hole is configured to penetrate in the vertical direction of the top wall, The plasma processing apparatus according to any one of claims 1 to 10.

12. The second gas supply path having the second gas supply hole is configured to bend from above the top wall in a lateral direction and penetrate the inner surface of the recess. The plasma processing apparatus according to any one of claims 1 to 11.

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