Plasma processing apparatus and plasma processing method

Abstract

To secure uniformity of plasma density to a substrate even when an upper wall part and a mounting table have a short gap.SOLUTION: A plasma processing apparatus includes a stage, a rotary drive mechanism, and a plurality of plasma sources. The stage is placed in a processing container and a substrate is placed on it. The rotary drive mechanism rotatively drives the stage. The plurality of plasma sources are located on an upper wall part of the processing container opposite the stage and are not arranged axisymmetrically on a rotation axis of the stage.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Conventionally, a plasma processing apparatus that generates plasma in a processing vessel using microwaves is known. In Patent Document 1, one antenna module that radiates microwaves is arranged at the central portion of the top wall of the processing vessel, and six antenna modules are arranged outside the central portion so as to surround the antenna module at the central portion, and a technique for uniformizing the plasma distribution has been proposed.

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 for uniformizing the plasma density with respect to a substrate even when the gap between the upper wall portion and the stage is shortened.

Means for Solving the Problems

[0005] A plasma processing apparatus according to an aspect of the present disclosure includes a stage, a rotation drive mechanism, and a plurality of plasma sources. The stage is arranged in a processing vessel on which a substrate is placed. The rotation drive mechanism rotationally drives the stage. The plurality of plasma sources are provided on the upper wall portion of the processing vessel facing the stage and are not arranged axially symmetrically with respect to the rotation axis of the stage.

Effects of the Invention

[0006] According to the present disclosure, even when the gap between the upper wall portion and the stage is shortened, the plasma density can be uniformized with respect to the substrate. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a plasma processing apparatus according to an embodiment. [Figure 2] Figure 2 shows an example of a conventional antenna module arrangement. [Figure 3] Figure 3 shows an example of the arrangement of an antenna module according to the embodiment. [Figure 4] Figure 4 is a diagram illustrating the operation of the plasma processing apparatus according to the embodiment. [Figure 5] Figure 5 shows an example of the results obtained by determining the plasma extent according to this embodiment. [Figure 6] Figure 6 shows an example of the relationship between plasma spread and gap according to the embodiment. [Figure 7] Figure 7 shows an example of the calculated plasma density distribution in the radial direction of the mounting platform according to the embodiment. [Figure 8] Figure 8 shows an example of the results of comparing the plasma density distribution of the embodiment with that of the conventional technology. [Figure 9] Figure 9 shows an example of the configuration of a shower head according to this embodiment. [Figure 10] Figure 10 is a flowchart showing an example of the plasma processing flow according to the embodiment. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments of the plasma processing apparatus and plasma processing method disclosed in this application will be described in detail with reference to the drawings. However, these embodiments do not limit the disclosed plasma processing apparatus and plasma processing method.

[0009] Incidentally, in plasma processing equipment, there is a desire to shorten the gap between the upper wall of the processing vessel where the antenna module is located and the stage on which the substrate is placed, considering factors such as productivity and energy saving. However, if the gap is shortened while maintaining the conventional arrangement of the antenna module, the plasma will not spread sufficiently, and uniformity of plasma density on the substrate cannot be ensured.

[0010] Therefore, there is a need for a technology that can equalize the plasma density on the substrate even when the gap between the upper wall and the mounting base is shortened.

[0011] [Embodiment] Embodiments will now be described. Figure 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 is a device that generates plasma using microwaves. The plasma processing apparatus 100 shown in Figure 1 includes a processing container 101, a mounting table 102, a gas supply mechanism 103, an exhaust device 104, a microwave introduction device 105, and a control unit 200.

[0012] The processing container 101 houses a substrate W such as a semiconductor wafer. The processing container 101 is provided with a mounting stage 102 inside. The substrate W is placed on the mounting stage 102. In this embodiment, the mounting stage 102 corresponds to the stage of this disclosure.

[0013] The gas supply mechanism 103 supplies gas into the processing vessel 101. The exhaust device 104 exhausts the processing vessel 101. The microwave introduction device 105 generates microwaves to create plasma in the processing vessel 101 and introduces microwaves into the processing vessel 101. The control unit 200 controls the operation of each part of the plasma processing apparatus 100.

[0014] The processing container 101 is formed of a metallic material such as aluminum and its alloys, etc., and has a substantially cylindrical shape. The processing container 101 has a plate-shaped top wall portion 111 and bottom wall portion 113, and a side wall portion 112 connecting these. A protective film coated with yttria (Y2O3) or the like is provided on the inner wall of the processing container 101.

[0015] The microwave introduction device 105 is provided above the processing container 101, and introduces electromagnetic waves (microwaves) into the processing container 101 to generate plasma. The microwave introduction device 105 will be described in detail later.

[0016] The top wall portion 111 has a plurality of openings into which a microwave radiation mechanism 143 (to be described later) of the microwave introduction device 105 is fitted. The side wall portion 112 has a loading / unloading port 114 for loading and unloading the substrate W between the processing container 101 and an adjacent transfer chamber (not shown). Further, a gas introduction nozzle 124 is provided on the side wall portion 112 at a position above the mounting table 102. The loading / unloading port 114 is configured to be opened and closed by a gate valve 115.

[0017] The bottom wall portion 113 is provided with an opening, and an exhaust device 104 is provided via an exhaust pipe 116 connected to the opening. The exhaust device 104 includes a vacuum pump and a pressure control valve. The inside of the processing container 101 is exhausted via the exhaust pipe 116 by the vacuum pump of the exhaust device 104. The pressure inside the processing container 101 is controlled by the pressure control valve of the exhaust device 104.

[0018] The mounting table 102 is formed in a disc shape. The mounting table 102 is made of, for example, aluminum with an anodic oxidation treatment on its surface, or a ceramic material such as aluminum nitride (AlN). The substrate W is placed on the upper surface of the mounting table 102. The mounting table 102 is supported by a support member 120 made of a ceramic such as cylindrical AlN at the central portion of the lower surface. A rotation drive mechanism 121 is provided at the center of the bottom of the processing container 101. The rotation drive mechanism 121 rotatably supports the support member 120. The mounting table 102 is rotatably supported by the support member 120 and the rotation drive mechanism 121. The rotation drive mechanism 121 has a built-in motor and rotates the mounting table 102 by rotating the support member 120 with the driving force of the motor. The mounting table 102 rotates in the circumferential direction with the central axis of the disc shape as the rotation axis. A guide ring 181 for guiding the substrate W is provided at the outer edge portion of the mounting table 102. Further, 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.

[0019] The mounting base 102 has a resistance heating type heater 182 embedded in it. An electrode 184, approximately the same size as the substrate W, is also embedded in the mounting base 102 above the heater 182. Furthermore, a thermocouple (not shown) is inserted into the mounting base 102. The heater 182, electrode 184, and thermocouple of the support member 120 are electrically connected to the rotational drive mechanism 121. For example, the rotational drive mechanism 121 is provided with slip rings, which are electrically connected to the wiring connected to the heater 182, electrode 184, and thermocouple via the slip rings. The heater 182 is connected to the heater power supply 183 via the rotational drive mechanism 121. The electrode 184 is connected to the DC power supply unit 122 via the rotational drive mechanism 121. The thermocouple is connected to the control unit 200 via the rotational drive mechanism 121. The heater 182 heats the substrate W placed on the mounting base 102 by being powered by the heater power supply 183. The mounting base 102 is also capable of controlling the heating temperature of the substrate W based on signals from the thermocouple. The DC power supply unit 122 periodically applies a DC voltage to the electrodes 184 in the mounting base 102. For example, the DC power supply unit 122 is composed of a DC power supply and a pulse unit. The DC power supply unit 122 periodically applies a pulsed DC voltage to the electrodes 184 by switching the DC voltage supplied by the DC power supply on and off using the pulse unit.

[0020] The gas supply mechanism 103 supplies various gases into the processing container 101. The gas supply mechanism 103 includes a gas introduction nozzle 124, a gas supply pipe 126, and a gas supply unit 127. The gas introduction nozzle 124 is fitted into an opening formed in the side wall 112 of the processing container 101. The gas supply unit 127 is connected to each gas introduction nozzle 124 via the gas supply pipe 126. The gas supply unit 127 has various gas supply sources. The gas supply unit 127 is also equipped with on / off valves for starting and stopping the supply of various gases, and a flow rate adjustment unit for adjusting the gas flow rate. The gas supply unit 127 supplies various gases, such as processing gases used for plasma processing.

[0021] The microwave introduction device 105 is located above the processing vessel 101. The microwave introduction device 105 generates plasma by introducing electromagnetic waves (microwaves) into the processing vessel 101.

[0022] The microwave introduction device 105 includes a microwave output unit 130 and an antenna unit 140. The microwave output unit 130 generates microwaves and distributes them to multiple paths for output. The antenna unit 140 introduces the microwaves output from the microwave output unit 130 into the processing container 101.

[0023] The microwave output unit 130 includes a microwave power supply, a microwave oscillator, an amplifier, and a distributor. The microwave oscillator is solid-state and, for example, oscillates microwaves at 860 MHz (e.g., PLL oscillation). Note that the microwave frequency is not limited to 860 MHz, but can be 2.45 GHz, 8.35 GHz, 5.8 GHz, 1.98 GHz, etc., in the range of 700 MHz to 10 GHz. The amplifier amplifies the microwaves oscillated by the microwave oscillator. The distributor distributes the microwaves amplified by the amplifier to multiple paths. The distributor distributes the microwaves while matching the impedance of the input and output sides.

[0024] The antenna unit 140 has a plurality of antenna modules 141. Figure 1 shows two antenna modules 141 of the antenna unit 140. In this embodiment, the antenna module 141 configured to supply electromagnetic waves (microwaves) into the processing vessel 101 corresponds to the plasma source of this disclosure.

[0025] The multiple antenna modules 141 are not arranged axially with respect to the axis of rotation of the mounting base 102, but are arranged asymmetrically with respect to the axis of rotation of the mounting base 102. Each antenna module 141 has an amplifier section 142 and a microwave radiation mechanism 143. The microwave output section 130 generates microwaves and distributes them to each antenna module 141. The amplifier section 142 of the antenna module 141 mainly amplifies the distributed microwaves and outputs them to the microwave radiation mechanism 143. The microwave radiation mechanism 143 is provided on the top wall section 111. The microwave radiation mechanism 143 radiates the microwaves output from the amplifier section 142 into the processing container 101. In this embodiment, the top wall section 111 corresponds to the top wall section of the processing container 101 of this disclosure.

[0026] The amplifier section 142 includes a phase shifter, a variable gain amplifier, a main amplifier, and an isolator. The phase shifter changes the phase of the microwave. The variable gain amplifier adjusts the power level of the microwave input to the main amplifier. The main amplifier is configured as a solid-state amplifier. The isolator separates the reflected microwave that is reflected by the antenna section of the microwave radiation mechanism 143 (described later) and heads towards the main amplifier.

[0027] Multiple microwave radiation mechanisms 143 are provided on the top wall 111, as shown in Figure 1. Each microwave radiation mechanism 143 has a cylindrical outer conductor and an inner conductor coaxially arranged within the outer conductor. Between the outer conductor and the inner conductor, each microwave radiation mechanism 143 has a coaxial tube having a microwave transmission path and an antenna section that radiates microwaves into the processing container 101. A microwave-transmitting plate 163, fitted into the top wall 111, is provided on the lower surface of the antenna section. The lower surface of the microwave-transmitting plate 163 is exposed to the internal space of the processing container 101. Microwaves that pass through the microwave-transmitting plate 163 generate plasma in the space inside the processing container 101. The position where the microwave-transmitting plate 163 is provided can be considered as the position where the plasma source is placed.

[0028] The antenna unit 140 is capable of adjusting the power of the microwaves radiated from the microwave radiation mechanism 143 of each antenna module 141 by controlling the amplifier section 142 of each antenna module 141.

[0029] The top wall section 111 is provided with an introduction section 150 for introducing remote plasma. The introduction section 150 is located at a position corresponding to the rotation axis of the mounting base 102. For example, the introduction section 150 is located on the rotation axis of the mounting base 102. A remote plasma unit 152 is connected to the introduction section 150 via piping 151. During cleaning, the remote plasma unit 152 generates remote plasma of the cleaning gas and supplies it to the piping 151. An example of the cleaning gas is NF3 gas. The plasma-generated cleaning gas is introduced into the processing container 101 from the introduction section 150 via piping 151.

[0030] The plasma processing apparatus 100, configured as described above, is comprehensively controlled by the control unit 200. The control unit 200 is connected to a user interface 210 and a storage unit 220.

[0031] The user interface 210 consists of an operation unit such as a keyboard for the process manager to input commands to manage the plasma processing apparatus 100, and a display unit such as a display that visualizes and shows the operating status of the plasma processing apparatus 100. The user interface 210 accepts various operations. For example, the user interface 210 accepts a predetermined operation that instructs the start of plasma processing.

[0032] The memory unit 220 is a memory device that stores various types of data. For example, the memory unit 220 is a storage device such as a hard disk, SSD (Solid State Drive), or optical disc. The memory unit 220 may also be a rewritable semiconductor memory such as RAM (Random Access Memory), flash memory, or NVSRAM (Non-Volatile Static Random Access Memory).

[0033] The memory unit 220 stores the OS (Operating System) and various recipes executed by the control unit 200. For example, the memory unit 220 stores various recipes, including a recipe for performing plasma processing and a recipe for performing cleaning inside the processing container 101. Furthermore, the memory unit 220 stores various data used in the recipes. Note that the programs and data may be stored on a computer-readable computer recording medium (e.g., hard disk, CD, flexible disk, semiconductor memory, etc.). Alternatively, the programs and data can be transmitted from other devices as needed, for example via a dedicated line, and used online.

[0034] The control unit 200 is a device that controls the plasma processing apparatus 100. The control unit 200 can employ electronic circuits such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), or integrated circuits such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). The control unit 200 has an internal memory for storing programs and control data that define various processing procedures, and executes various processes using these.

[0035] The control unit 200 controls each part of the plasma processing apparatus 100. For example, the control unit 200 controls each part of the plasma processing apparatus 100 to perform plasma processing and cleaning according to the recipe in the recipe data stored in the memory unit 220. For example, the plasma processing apparatus 100 performs plasma processing on a substrate W placed on the mounting table 102. The plasma processing apparatus 100 generates microwave plasma in the processing container 101.

[0036] In conventional plasma processing equipment, multiple plasma sources are arranged symmetrically with respect to the center of the stage, which is the center of the substrate, in order to equalize the plasma density on the substrate. As a comparative example, an example of the arrangement of conventional plasma sources will be described. For example, in the plasma processing equipment of Patent Document 1, one antenna module is placed in the central part of the top wall of the processing vessel, and six antenna modules are placed outside the central part, surrounding the antenna module in the central part.

[0037] Figure 2 shows an example of the arrangement of a conventional antenna module 141. Seven antenna modules 141 are provided on the top wall 111. In Figure 2, the microwave radiation mechanism 143 of the antenna module 141 is shown as "CELL". Six of the microwave radiation mechanisms 143 are arranged so that they form the vertices of a regular hexagon, and one is positioned at the center of the regular hexagon. In addition, microwave transparent plates 163 are arranged on the top wall 111, corresponding to each of the seven microwave radiation mechanisms 143. These seven microwave transparent plates 163 are arranged so that adjacent microwave transparent plates 163 are equally spaced.

[0038] Incidentally, as mentioned above, the plasma processing apparatus 100 is desired to have a shorter gap between the top wall 111 and the mounting base 102, taking into consideration productivity and energy saving. Furthermore, from the viewpoint of cost reduction, it is also desired to reduce the number of antenna modules 141. However, if the gap is shortened while maintaining the conventional arrangement of antenna modules 141, the arrangement of the antenna modules 141 will be transferred, and uniformity of the plasma on the substrate W cannot be ensured. For example, in the case of Figure 2, the arrangement of the seven antenna modules 141 will be transferred to the substrate W.

[0039] Therefore, the plasma processing apparatus 100 according to the embodiment is configured to allow the mounting base 102 to rotate by rotating the support member 120 with a rotary drive mechanism 121. Furthermore, the plasma processing apparatus 100 according to the embodiment does not arrange the multiple antenna modules 141 on the top wall portion 111 symmetrically with respect to the rotation axis of the mounting base 102, but rather arranges them asymmetrically with respect to the rotation axis of the mounting base 102. Figure 3 is a diagram showing an example of the arrangement of the antenna modules 141 according to the embodiment. Four antenna modules 141 are provided on the top wall portion 111. In Figure 3, the microwave radiation mechanism 143 of the antenna module 141 is also shown as "CELL". The multiple antenna modules 141 are arranged on the top wall portion 111 such that when plasma is generated with a predetermined power, the distribution of plasma density in the radial direction of the mounting base 102 is within a predetermined range. The predetermined range is determined according to the conditions required for plasma processing.

[0040] Figure 4 is a diagram illustrating the operation of the plasma processing apparatus 100 according to the embodiment. The plasma processing apparatus 100 according to the embodiment generates microwave plasma in the processing container 101 by introducing microwaves from each antenna module 141 while rotating the mounting table 102. For example, when the control unit 200 performs plasma processing on the substrate W, it rotates the mounting table 102 using the rotation drive mechanism 121. The control unit 200 controls the gas supply unit 127 and the microwave introduction device 105, supplying processing gas used for plasma processing into the processing container 101 from the gas supply unit 127, while introducing microwaves into the processing container 101 from each antenna module 141 to generate plasma.

[0041] In the plasma processing apparatus 100 according to this embodiment, the mounting table 102 is rotatable by a rotary drive mechanism 121, so that the plasma density on the substrate W can be made uniform even if the antenna modules 141 are not arranged axially with respect to the rotation axis of the mounting table 102. Furthermore, the plasma processing apparatus 100 according to this embodiment can reduce the number of antenna modules 141, thereby achieving cost reduction. Moreover, the plasma processing apparatus 100 according to this embodiment can maintain a uniform plasma density on the substrate even with fewer antenna modules 141 than in conventional devices.

[0042] However, in conventional apparatus configurations, it was necessary to place the antenna module 141 in the center to ensure uniformity of plasma density. Therefore, in conventional apparatus configurations, even when it was desired to clean the inside of the processing vessel 101 with a milder remote plasma than direct plasma, it was impossible to introduce the remote plasma from the center, and thus it was not possible to perform uniform cleaning inside the processing vessel 101.

[0043] In contrast, the plasma processing apparatus 100 according to the embodiment does not require the antenna module 141 to be placed in the center of the top wall portion 111. The plasma processing apparatus 100 according to the embodiment has an introduction section 150 for introducing remote plasma located near the center of the top wall portion 111. The introduction section 150 is located at a position corresponding to the rotation axis of the mounting base 102. During cleaning, the plasma processing apparatus 100 generates remote plasma of the cleaning gas using a remote plasma unit 152, and introduces the plasma-generated cleaning gas into the processing container 101 from the introduction section 150 via piping 151. In this way, the plasma processing apparatus 100 according to the embodiment can uniformly clean the inside of the processing container 101 by introducing the plasma-generated cleaning gas from the remote plasma into the processing container 101 from near the center of the top wall portion 111.

[0044] Next, the arrangement of the antenna module 141 in the plasma processing apparatus 100 according to the embodiment will be described. The antenna module 141 generates plasma using microwaves. The density of the plasma generated by microwaves decreases as the distance from the antenna module 141 increases. Figure 5 is a diagram showing an example of the results of determining the plasma spread according to the embodiment. Figure 5 shows the distribution of plasma density when generated by radiating microwaves from one antenna module 141. The horizontal axis of Figure 5 is the distance from the reference point on the mounting table 102, with the reference point being the position on the mounting table 102 directly below the center of the microwave transmitting plate 163. The vertical axis is the plasma density. The plasma density is a normalized value. Line L11 is the result of measuring the plasma density at a distance r from the reference point on the mounting table 102. Line L11 can be approximated by the following equation (1). The value of parameter a in equation (1) is determined by fitting. Line L12 is the line obtained from equation (1) by applying the value of parameter a determined by fitting.

[0045]

number

[0046] Here, d is the plasma density. r is the distance on the mounting platform 102. 'a' is a parameter.

[0047] Figure 6 shows an example of the relationship between plasma spread and gap according to the embodiment. Figure 6 shows the relationship between the distance (Gap) between the top wall 111 on which the antenna module 141 is installed and the mounting base 102, and the full width at half maximum (FWHM) at which the plasma density distribution is halved. The horizontal axis of Figure 6 is the distance (Gap) between the top wall 111 on which the antenna module 141 is installed and the mounting base 102. The vertical axis is the FWHM at which the plasma density distribution is halved. Figure 6 shows an approximate straight line that approximates the relationship between x and y, where x is the distance (Gap) and y is the FWHM, and the equation of the approximate straight line. As shown in Figure 6, the smaller the gap between the top wall 111 and the mounting base 102, the smaller the FWHM of the plasma density. For example, when the gap is 40 mm, the FWHM is 37.6 mm. Therefore, if the gap between the top wall 111 and the mounting base 102 is shortened, the plasma generated by each antenna module 141 will not spread sufficiently, and uniformity of plasma density on the substrate W cannot be ensured.

[0048] On the other hand, the plasma processing apparatus 100 according to the embodiment is configured to have a rotatable mounting base 102, thereby arranging each antenna module 141 asymmetrically with respect to the rotation axis of the mounting base 102, and even if the number of antenna modules 141 is reduced compared to conventional methods, the plasma density can be made uniform with respect to the substrate W.

[0049] An example of the arrangement of the antenna module 141 according to the embodiment will be described. During substrate processing, the substrate W rotates in conjunction with the rotation of the mounting table 102. Each antenna module 141 should be positioned relative to the radial direction of the mounting table 102 and have its microwave radiating power determined so as to ensure uniformity of plasma density with respect to the radial direction of the mounting table 102.

[0050] Figure 7 shows an example of the calculated distribution of plasma density in the radial direction of the mounting base 102 according to the embodiment. The horizontal axis of Figure 7 represents the radial distance from the center of the mounting base 102. The vertical axis represents the plasma density. The plasma density is a normalized value. The left side of Figure 7B shows a graph showing the overall distribution of plasma density in the radial direction of the mounting base 102. The right side of Figure 7 shows an enlarged view of the graph where the plasma density is around 0.998 to 1.003.

[0051] Each antenna module 141 shall be positioned at a distance r from the center of the mounting base 102 within the range of 0 ≤ r ≤ 220. Each antenna module 141 shall have a distance ri from the center of the mounting base 102 and a microwave radiating power pi. i is a number assigned sequentially to each antenna module 141, starting from 1, from the side closest to the center of the mounting base 102. The microwave radiating power P shall be set so that the power P1 of the innermost antenna module 141 with number i=1 is 1 (P1=1), and the power Pi of each antenna module 141 with number i ≤ 2 shall be in the range of 0.5 or more and 2 or less (0.5 ≤ Pi ≤ 2).

[0052] First, as Calculation Example 1, we will explain an example of calculating the plasma density distribution when the gap between the top wall 111 and the mounting base 102 is 80 mm and seven antenna modules 141 are arranged. When the gap is 80 mm, the half-width of the plasma density is 61.2 mm. The arrangement positions of the seven antenna modules 141 (i=1 to 7) are r1=53.2, r2=111, r3=136, r4=162, r5=220, r6=220, and r7=220. The power P emitted by the seven antenna modules 141 (i=1 to 7) is p1=1, p2=0.952, p3=1.60, p4=0.835, p5=1.79, p6=1.81, and p7=1.82. Figure 7 shows the plasma density distribution for Calculation Example 1 as a dashed line. Calculation Example 1 shows that the plasma density can be made uniform to approximately 1.000.

[0053] Next, as calculation example 2, we will explain an example of calculating the plasma density distribution when the gap between the top wall 111 and the mounting base 102 is 40 mm and seven antenna modules 141 are arranged. When the gap is 40 mm, the half-width of the plasma density is 37.6 mm. The arrangement positions of the seven (i=1~7) antenna modules 141 are r1=36.6, r2=81.4, r3=118, r4=140, r5=171, r6=186, and r7=186. The power P emitted by four (i=1~7) antenna modules 141 is p1=1, p2=p3=p4=p5=p6=p7=2.0. Figure 7 shows the plasma density distribution for calculation example 2 as a solid line. Compared to calculation example 1, calculation example 2 shows some irregularities, but it is within the range of 1.003 to 0.998, indicating that the plasma density has been sufficiently homogenized.

[0054] Figure 8 shows an example of a comparison of the plasma density distribution between the embodiment and the prior art. The horizontal axis in Figure 8 represents the radial distance from the center of the mounting platform 102. The vertical axis represents the plasma density. The plasma density is shown in a normalized form. The left side of Figure 8 shows a graph illustrating the overall distribution of plasma density in the radial direction of the mounting platform 102, and the right side of Figure 8 shows an enlarged view of the graph for plasma densities around 0.98 to 1.04.

[0055] Figure 8 shows the plasma density distribution for Calculation Example 1 described above. Figure 8 also shows the plasma density distribution for Calculation Example 3. Calculation Example 3 calculates the plasma density distribution when the gap between the top wall 111 and the mounting base 102 is 40 mm and four antenna modules 141 are arranged. The placement positions of the four (i=1~4) antenna modules 141 are r1=45.3, r2=102, r3=151, and r4=170. The power P emitted by the four (i=1~4) antenna modules 141 is p1=1, p2=p3=p4=2.0. Figure 8 also shows the plasma density distribution of a comparative example. The comparative example is when seven antenna modules 141 are arranged at the vertices and center of a regular hexagon, as shown in Figure 2. In the comparative example, only the power P emitted by the seven antenna modules 141 is optimized. As shown in Figure 8, calculation example 1 and calculation example 3 achieve a more uniform plasma density than the comparative example. For example, calculation example 3 achieves a sufficiently uniform plasma density even when the number of antenna modules 141 is reduced to four.

[0056] In the plasma processing apparatus 100 according to this embodiment, the number of antenna modules 141 arranged on the top wall portion 111 is not limited to 4 or 7. The number of antenna modules 141 may be 7 or less. Also, the arrangement position of each antenna module 141 and the power P for radiating microwaves are examples only and are not limited thereto. The arrangement position and power P should be determined so that the distribution of plasma density falls within a predetermined range that should be satisfied by the plasma processing.

[0057] When the placement position and power P are optimized to achieve a uniform plasma density in this way, each antenna module 141 is not arranged symmetrically with respect to the axis of rotation of the mounting base 102, but rather asymmetrically with respect to the axis of rotation of the mounting base 102. Furthermore, each antenna module 141 is arranged such that the placement density in the radial direction of the mounting base 102 increases towards the outer edges. In other words, each antenna module 141 is arranged with shorter radial spacing towards the outer edges of the mounting base 102.

[0058] If each antenna module 141 is positioned unevenly on one side of the top wall 111, the weight balance will be poor. Also, if each antenna module 141 is positioned unevenly on one side of the top wall 111, the surrounding space will be narrowed, making it difficult to handle wiring and potentially causing interference with other components. For this reason, it is preferable to position each antenna module 141 on the top wall 111 so that they are spaced apart from each other. For example, it is preferable to position each antenna module 141 such that the inner and outer antenna modules 141 appear alternately with respect to the rotational direction of the mounting base 102 and the radial direction of the mounting base 102.

[0059] The plasma processing apparatus 100 according to the embodiment can sufficiently equalize the plasma density on the substrate W even when the number of antenna modules 141 arranged on the top wall portion 111 is reduced, by configuring the mounting base 102 to be rotatable. Furthermore, the plasma processing apparatus 100 can arrange the antenna modules 141 on the top wall portion 111 asymmetrically with respect to the rotation axis of the mounting base 102. As shown in Figure 3, reducing the number of antenna modules 141 on the top wall portion 111 reduces the proportion occupied by the microwave-transmitting plate 163. Also, it becomes unnecessary to arrange the microwave-transmitting plate 163 near the center of the top wall portion 111. Therefore, the plasma processing apparatus 100 according to the embodiment may be provided with a shower head that sprays gas onto the top wall portion 111 where antenna modules 141 are not arranged. Figure 9 is a diagram showing an example of the configuration of the shower head according to the embodiment. Figure 9 shows an example of the configuration of the shower head 190. The shower head 190 is provided on the inner surface of the processing container 101 of the top wall portion 111 in the portion where antenna modules 141 are not arranged. Each showerhead 190 has a gas outlet 191 formed on its lower surface for ejecting gas. This allows the plasma processing apparatus 100 according to the embodiment to supply gas to the entire substrate W from the upper side.

[0060] The shower head 190 may be configured to allow adjustment of the type and amount of gas dispensed for each region. For example, the shower head 190 has multiple partitioned spaces 192 inside, each for a different region. The nozzle 191 communicates with one of the spaces 192. Each space 192 is connected to a gas supply unit 127 via piping (not shown). The gas supply unit 127 supplies various gases, such as processing gases used for plasma processing, to each space 192 via piping. The nozzle 191 ejects the gas supplied to the communicating spaces 192. As a result, the plasma processing apparatus 100 according to this embodiment can adjust the type and amount of gas supplied from the top side for each region. Alternatively, the shower head 190 may be provided integrated with the top wall 111 by providing spaces 192 within the top wall 111.

[0061] [Plasma treatment method] Next, the plasma processing flow according to the plasma processing method of the embodiment will be described. Figure 10 is a flowchart showing an example of the plasma processing flow according to the embodiment. When plasma processing is performed in the plasma processing apparatus 100, the substrate W to be subjected to plasma processing is placed on the mounting table 102.

[0062] The plasma processing apparatus 100 rotates the mounting table 102 (step S10). For example, the control unit 200 rotates the mounting table 102 using the rotation drive mechanism 121.

[0063] The plasma processing apparatus 100 generates plasma in the processing container 101 while supplying processing gas into the processing container 101, and performs plasma processing on the substrate W (step S11). For example, the control unit 200 controls the gas supply unit 127 and the microwave introduction device 105, supplying processing gas from the gas supply unit 127 into the processing container 101, while introducing microwaves from each antenna module 141 into the processing container 101 to generate plasma.

[0064] The plasma processing apparatus 100 determines whether or not to terminate the processing (step S12). For example, the control unit 200 determines whether a predetermined processing time has elapsed since the start of plasma processing, and if the predetermined processing time has elapsed (step S12: Yes), it terminates the processing. On the other hand, if the predetermined processing time has not elapsed (step S12: No), it proceeds to step S10 and continues the processing.

[0065] As described above, the plasma processing apparatus 100 according to the embodiment includes a mounting table 102 (stage), a rotational drive mechanism 121, and a plurality of antenna units 140 (plasma sources). The mounting table 102 is placed inside the processing container 101, on which the substrate W is placed. The rotational drive mechanism 121 rotates the mounting table 102. The plurality of antenna units 140 are provided on the top wall portion 111 (upper wall portion) of the processing container 101 facing the mounting table 102, and are not arranged axially symmetrically with respect to the rotation axis of the mounting table 102. As a result, the plasma processing apparatus 100 according to the embodiment can equalize the plasma density on the substrate W even when the gap between the top wall portion 111 and the mounting table 102 is made short.

[0066] Furthermore, the multiple antenna units 140 are arranged such that when each generates plasma at a predetermined power, the distribution of plasma density in the radial direction of the mounting table 102 falls within a predetermined range. When the control unit 200 performs plasma processing on the substrate W placed on the mounting table 102, it rotates the mounting table 102 using the rotation drive mechanism 121 and controls the multiple antenna units 140 to generate plasma at a predetermined power. As a result, even when the gap between the top wall portion 111 and the mounting table 102 is shortened, the plasma processing apparatus 100 according to the embodiment can maintain the distribution of plasma density in the radial direction of the mounting table 102 within a predetermined range, thereby achieving uniform plasma density on the substrate W.

[0067] Furthermore, the multiple antenna units 140 are each positioned at different locations with respect to the radial direction of the mounting base 102. In addition, the multiple antenna units 140 are arranged such that the arrangement density with respect to the radial direction of the mounting base 102 is higher towards the outside. As a result, the plasma processing apparatus 100 according to the embodiment can equalize the plasma density with respect to the radial direction of the mounting base 102.

[0068] Furthermore, the multiple antenna units 140 are arranged such that, with respect to the rotational direction of the mounting base 102, the antenna units 140 on the inside and outside of the mounting base 102 appear alternately in the radial direction of the mounting base 102. In addition, the multiple antenna units 140 are arranged so that they are far apart from each other. As a result, the plasma processing apparatus 100 according to the embodiment can secure space around each antenna module 141, suppressing deterioration of wiring and the occurrence of interference with other components. It can also suppress interference of electromagnetic waves introduced from each antenna module within the processing container 101.

[0069] Furthermore, the multiple antenna units 140 are not positioned at locations corresponding to the rotation axis of the mounting base 102 on the top wall 111. In addition, an introduction section 150 for introducing remote plasma is provided at a location corresponding to the rotation axis of the mounting base 102 on the top wall 111. As a result, the plasma processing apparatus 100 according to the embodiment can introduce cleaning gas plasma-generated by remote plasma into the processing container 101 from near the center of the top wall 111, and can uniformly clean the inside of the processing container 101.

[0070] Furthermore, the number of antenna units 140 is seven or less. The plasma processing apparatus 100 according to this embodiment can ensure uniformity of plasma density with respect to the substrate W even when the number of antenna units 140 is seven or less (for example, four).

[0071] Furthermore, the processing container 101 is equipped with a shower head that sprays gas onto the top wall portion 111 where the multiple antenna units 140 are not located. This allows the plasma processing apparatus 100 according to the embodiment to supply gas to the entire substrate W from the top side.

[0072] While embodiments have been described above, it should be understood that the embodiments disclosed herein are illustrative and not restrictive in all respects. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the claims.

[0073] For example, in the above embodiment, the case where the substrate W is a semiconductor wafer was described as an example, but it is not limited to this. The substrate W may be any other material.

[0074] Furthermore, although the above embodiment describes an example where the plasma source is an antenna module 141 that generates plasma using microwaves, it is not limited to this. The plasma source can be any device capable of generating plasma.

[0075] Furthermore, although the above embodiment described an example in which the plasma processing apparatus is a device that generates plasma using microwaves, it is not limited to this. The plasma processing apparatus may be any device that generates plasma using multiple plasma sources.

[0076] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0077] Furthermore, the following additional information is disclosed regarding the above embodiments.

[0078] (Note 1) A stage placed inside the processing container on which the substrate is mounted, A rotational drive mechanism for rotating the aforementioned stage, A plurality of plasma sources are provided on the upper wall of the processing container facing the stage, and are not arranged axially with respect to the rotation axis of the stage, A plasma processing device.

[0079] (Note 2) The plurality of plasma sources are arranged such that when each generates plasma with a predetermined power, the distribution of plasma density in the radial direction of the stage falls within a predetermined range. When performing plasma processing on a substrate placed on the stage, the system further includes a control unit that rotates the stage using the rotation drive mechanism while controlling the generation of plasma from each of the plurality of plasma sources at a predetermined power. The plasma processing apparatus described in Appendix 1.

[0080] (Note 3) The plasma processing apparatus according to Appendix 1 or 2, wherein the plurality of plasma sources are provided at different positions with respect to the radial direction of the stage.

[0081] (Note 4) The plasma processing apparatus according to any one of the appendices 1 to 3, wherein the plurality of plasma sources are arranged such that the plasma sources on the inside and outside of the stage appear alternately with respect to the rotational direction of the stage.

[0082] (Note 5) The plasma processing apparatus according to any one of the appendices 1 to 4, wherein the plurality of plasma sources are arranged such that their arrangement density in the radial direction of the stage increases towards the outside.

[0083] (Note 6) The plasma processing apparatus according to any one of the appendices 1 to 5, wherein the plurality of plasma sources are arranged at a distance from each other.

[0084] (Note 7) The aforementioned plurality of plasma sources are not positioned in a location corresponding to the rotation axis of the stage on the upper wall. A plasma processing apparatus as described in any one of the appendices 1 to 6.

[0085] (Note 8) An introduction section for introducing remote plasma is provided at a position corresponding to the rotation axis of the stage on the upper wall. The plasma processing apparatus described in Appendix 7.

[0086] (Note 9) The number of the aforementioned plasma sources is 7 or less. A plasma processing apparatus as described in any one of the appendices 1 to 8.

[0087] (Note 10) The processing vessel is provided with a shower head that ejects gas from the upper wall portion where the plurality of plasma sources are not located. A plasma processing apparatus as described in any one of the appendices 1 to 9.

[0088] (Note 11) A stage is placed inside the processing container and rotated, on which the substrate is mounted. Plasma is generated by a plurality of plasma sources provided on the upper wall of the processing vessel facing the stage, which are not arranged axially symmetrically with respect to the rotation axis of the stage. Plasma treatment method. [Explanation of Symbols]

[0089] 100 Plasma Processing Equipment 101 Processing container 102 Mounting platform 105 Microwave introduction device 111 Top wall section 120 Support member 121 Rotary drive mechanism 124 Gas introduction nozzle 126 Gas supply piping 127 Gas Supply Department 130 Microwave output section 140 Antenna Unit 141 Antenna Module 142 Amplifier section 143 Microwave Emission Mechanism 150 Introduction 151 Piping 152 Remote Plasma Unit 163 Microwave-transmitting plate 190 shower head 191 spout 192 Space 200 Control Unit 210 User Interface 220 Storage section W board

Claims

1. A stage placed inside the processing container on which the substrate is mounted, A rotational drive mechanism for rotating the aforementioned stage, A plurality of plasma sources are provided on the upper wall of the processing vessel facing the stage, and are not arranged axially with respect to the rotation axis of the stage, but are arranged to appear alternately on the inside and outside of the radial direction of the stage with respect to the rotation direction of the stage, A plasma processing device.

2. A stage placed inside the processing container on which the substrate is mounted, A rotational drive mechanism for rotating the aforementioned stage, A plurality of plasma sources are provided on the upper wall of the processing vessel facing the stage, and are not arranged axially with respect to the rotation axis of the stage, but are arranged such that the arrangement density with respect to the radial direction of the stage increases towards the outside, A plasma processing device.

3. A stage placed inside the processing container on which the substrate is mounted, A rotational drive mechanism for rotating the aforementioned stage, A plurality of plasma sources are provided on the upper wall of the processing container facing the stage, and are not arranged axially with respect to the rotation axis of the stage, nor are they positioned on the upper wall corresponding to the rotation axis of the stage. An introduction section for introducing remote plasma is provided at a position corresponding to the rotation axis of the stage on the upper wall, A plasma processing device.

4. The plurality of plasma sources are arranged such that when each generates plasma with a predetermined power, the distribution of plasma density in the radial direction of the stage falls within a predetermined range. When performing plasma processing on a substrate placed on the stage, the system further includes a control unit that rotates the stage using the rotation drive mechanism while controlling the generation of plasma from each of the plurality of plasma sources at a predetermined power. A plasma processing apparatus according to any one of claims 1 to 3.

5. The plasma processing apparatus according to any one of claims 1 to 3, wherein the plurality of plasma sources are provided at different positions with respect to the radial direction of the stage.

6. The plasma processing apparatus according to any one of claims 1 to 3, wherein the plurality of plasma sources are arranged to be far apart from each other.

7. The number of the aforementioned plasma sources is seven or less. A plasma processing apparatus according to any one of claims 1 to 3.

8. The processing vessel is provided with a shower head that ejects gas from the upper wall portion where the plurality of plasma sources are not located. A plasma processing apparatus according to any one of claims 1 to 3.

9. A stage is placed inside the processing container and rotated, on which the substrate is mounted. Plasma is generated by a plurality of plasma sources provided on the upper wall of the processing vessel facing the stage, which are not axially symmetrical with respect to the rotation axis of the stage, but are arranged to alternately appear on the inside and outside of the radial direction of the stage with respect to the rotation direction of the stage. Plasma treatment method.

10. A stage is placed inside the processing container and rotated, on which the substrate is mounted. Plasma is generated by a plurality of plasma sources provided on the upper wall of the processing vessel facing the stage, which are not arranged axially with respect to the rotation axis of the stage, and are arranged such that the arrangement density with respect to the radial direction of the stage increases towards the outside. Plasma treatment method.

11. A stage is placed inside the processing container and rotated, on which the substrate is mounted. Plasma is generated by multiple plasma sources provided on the upper wall portion of the processing vessel facing the stage, which is provided with an introduction section for introducing remote plasma at a position corresponding to the rotation axis of the stage, and which are not arranged axially with respect to the rotation axis of the stage, and are not located on the upper wall portion corresponding to the rotation axis of the stage. Plasma treatment method.

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