Plasma processing apparatus and plasma processing method

Abstract

The present invention provides a plasma processing apparatus and a plasma processing method capable of suitably processing substrates. [Solution] The plasma processing apparatus comprises a generation chamber connected to a raw material supply unit and generating plasma from raw materials supplied from the raw material supply unit; a processing chamber adjacent to the generation chamber where a substrate is placed; and a filter placed between the generation chamber and the processing chamber and allowing some of the particles contained in the generated plasma to pass through, the filter having holes connected to the generation chamber and the processing chamber.

Description

Technical Field

[0001] This embodiment relates to a plasma processing apparatus and a plasma processing method.

Background Art

[0002] A plasma processing apparatus including a plasma generation chamber that generates plasma and a processing chamber that processes a substrate with the generated plasma is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] To provide a plasma processing apparatus and a plasma processing method capable of suitably processing a substrate.

Means for Solving the Problems

[0005] A plasma processing apparatus according to one embodiment includes a generation chamber connected to a raw material supply unit and generating plasma of a raw material supplied from the raw material supply unit, a processing chamber adjacent to the generation chamber and in which a substrate is disposed, and a filter disposed between the generation chamber and the processing chamber and allowing a part of particles contained in the generated plasma to pass therethrough. The filter includes a hole continuous with the generation chamber and the processing chamber and a heater for heating the hole.

Brief Description of the Drawings

[0006] [Figure 1] It is a schematic cross-sectional view of a plasma processing apparatus according to the first embodiment. [Figure 2A] This is a diagram illustrating a filter, specifically a schematic plan view of the filter as seen from above. [Figure 2B] This is a schematic cross-sectional view of the filter. [Figure 3] This is a schematic cross-sectional view showing how plasma particles pass through holes. [Figure 4A] This figure shows a filter according to the second embodiment, and is a schematic plan view of the filter as seen from above. [Figure 4B] This is a schematic cross-sectional view of the filter. [Figure 5] This is a schematic cross-sectional view of a plasma processing apparatus according to the third embodiment. [Figure 6] This is an explanatory diagram showing the voids in the substrate under various conditions. [Figure 7] This is an explanatory diagram showing the voids in the substrate under various conditions. [Modes for carrying out the invention]

[0007] Next, a plasma processing apparatus according to an embodiment will be described in detail with reference to the drawings. Note that the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, the following drawings are schematic, and some components may be omitted for illustrative purposes. Also, common parts in multiple embodiments are denoted by the same reference numerals, and their descriptions may be omitted.

[0008] Furthermore, in this specification, when we say that the first configuration is "electrically connected" to the second configuration, the first configuration may be directly connected to the second configuration, or it may be connected to the second configuration via wiring or the like.

[0009] In this specification, a predetermined direction parallel to the upper surface of a stage on which a substrate can be placed is referred to as the X direction, a direction parallel to the upper surface of the stage and perpendicular to the X direction is referred to as the Y direction, and a direction perpendicular to the upper surface of the stage is referred to as the Z direction.

[0010] Furthermore, in this specification, when we refer to the "width," "length," or "thickness" of a component or member in a predetermined direction, it may mean the width, length, or thickness of a cross-section observed by an SEM (Scanning Electron Microscopy) or the like.

[0011] [First Embodiment] [structure] Figure 1 is a schematic cross-sectional view showing a plasma processing apparatus 100 according to the first embodiment. The plasma processing apparatus 100 is configured as a plasma CVD apparatus (chemical vapor deposition apparatus) that, for example, processes a substrate W with plasma to form a predetermined layer on the surface of the substrate W.

[0012] The plasma processing apparatus 100 comprises a generation chamber 10 for generating raw material plasma, a processing chamber 20 adjacent to the generation chamber 10 where the substrate W is placed, and a filter 30 positioned between the generation chamber 10 and the processing chamber 20.

[0013] The generation chamber 10 comprises an upper wall portion 11 extending in a planar direction including the X and Y directions (hereinafter simply referred to as the planar direction), and a side wall portion 15 connected to the planar end of the upper wall portion 11 and extending in the Z direction below the upper wall portion 11. The interior 10A of the generation chamber 10 is the space between the filter 30 and the upper wall portion 11, and is a space partitioned by the filter 30, the upper wall portion 11, and the side wall portion 15.

[0014] The upper wall section 11 serves as a raw material supply section (sometimes called a showerhead) that supplies the raw material gas (shown as Gas in Figure 1) used for processing the substrate W into the interior 10A of the generation chamber 10. The generation chamber 10 is connected to the upper wall section 11 as the raw material supply section. The upper wall section 11 is arranged in a planar direction and has a plurality of supply ports 13 that open in the Z direction. The upper wall section 11 can supply the raw material gas from the outside of the generation chamber 10 to the interior 10A by passing the raw material gas through the plurality of supply ports 13. The generation chamber 10 can generate plasma of the raw material by plasmaizing the raw material gas supplied to the interior 10A through the supply ports 13.

[0015] The side wall portion 15 includes a communication portion 16 connected to a pressure gauge 19 for measuring the pressure inside the generation chamber 10 (hereinafter referred to as the internal pressure of the generation chamber 10), and a discharge portion 17 for discharging gas or the like inside the generation chamber 10 to the outside. The discharge portion 17 is connected to a first pressure adjustment mechanism 18 for adjusting the internal pressure of the generation chamber 10. The side wall portion 15 may be an insulator made of a material such as aluminum oxide. The first pressure adjustment mechanism 18 is, for example, a valve for adjusting the exhaust volume of gas or the like discharged from the discharge portion 17. This valve may be, for example, an APC valve that can adjust the exhaust volume in conjunction with the pressure gauge 19. If the internal pressure of the generation chamber 10 is lower than an arbitrarily specified pressure, the opening degree of this valve is reduced to decrease the exhaust volume, and if it is higher, the opening degree of this valve is increased to increase the exhaust volume. A vacuum pump may be connected downstream of the first pressure adjustment mechanism 18. Note that the method for adjusting the internal pressure of the generation chamber 10 by the first pressure adjustment mechanism 18 is not particularly limited. Also, the side wall portion 15 is not limited to an insulator and may be made of metal. In that case, the generation chamber 10 may include an insulating portion (such as a ring made of a material such as aluminum oxide) for insulating the upper wall portion 11 and the side wall portion 15.

[0016] The plasma generation method in the generation chamber 10 is a capacitively coupled plasma method (CCP method). The plasma processing apparatus 100 includes a blocking capacitor 51, a high-frequency power source 52, and a ground 53 that are electrically connected to the upper wall portion 11 via a power supply line. In the present embodiment, the upper wall portion 11 as the raw material supply portion corresponds to the first electrode portion.

[0017] When power is supplied from the high-frequency power source 52 and a high-frequency voltage of a predetermined frequency is applied to the upper wall portion 11, the generation chamber 10 can plasmaize the gas of the raw material supplied to its interior 10A and generate the plasma of the raw material. Note that the plasma generation method in the generation chamber 10 is not particularly limited, and in addition to the above CCP method, an inductively coupled plasma discharge method (ICP method), a hollow cathode discharge method, or the like may also be used.

[0018] The raw materials supplied to the generation chamber 10 are not particularly limited, and various gases (gas species) used in the processing of the substrate W can be used as appropriate. For example, at least one of the following can be used as the raw material: tetraethoxysilane (TEOS) gas used to form a silicon oxide film (SiO film) on the substrate W, silane (SiH4)-based gas used to form a silicon nitride film (SiN film) on the substrate W, and hydrocarbon (CH4, C2H6, etc.)-based gas used to form a carbon film on the substrate W. The raw materials may also contain carrier gases such as argon or helium.

[0019] The processing chamber 20 comprises a lower wall portion 21 extending in the planar direction, and a side wall portion 22 connected to the planar end of the lower wall portion 21 and extending in the Z direction above the lower wall portion 21. The interior 20A of the processing chamber 20 is the space between the filter 30 and the lower wall portion 21, and is a space partitioned by the filter 30, the lower wall portion 21, and the side wall portion 22. The lower wall portion 21 is electrically connected to and grounded to earth 57.

[0020] The lower wall section 21 is equipped with a discharge section 27 for discharging gas and other substances from the inside 20A of the processing chamber 20 to the outside. The discharge section 27 is connected to a second pressure adjustment mechanism 28 for adjusting the pressure inside 20A of the processing chamber 20 (hereinafter referred to as the internal pressure of the processing chamber 20). The side wall section 22 is equipped with a communication section 26 connected to a pressure gauge 29 for measuring the internal pressure of the processing chamber 20. The second pressure adjustment mechanism 28 may be, for example, an APC valve that can adjust the exhaust volume in conjunction with the pressure gauge 29. If the internal pressure of the processing chamber 20 is lower than an arbitrarily specified pressure, the opening of the valve can be reduced to decrease the exhaust volume, and if it is higher, the opening of the valve can be increased to increase the exhaust volume. A vacuum pump may be connected downstream of the second pressure adjustment mechanism 28. The method for adjusting the internal pressure of the processing chamber 20 by the second pressure adjustment mechanism 28 is not particularly limited.

[0021] The plasma processing apparatus 100 adjusts the pressure so that the processing chamber 20 is at a lower pressure than the generation chamber 10 by driving at least one of the first pressure adjustment mechanism 18 and the second pressure adjustment mechanism 28. If, as a result of measuring the internal pressure of the generation chamber 10 and the processing chamber 20 by pressure gauges 19 and 29, the internal pressure of the processing chamber 20 is greater than or equal to the internal pressure of the generation chamber 10, the internal pressure of the processing chamber 20 may be reduced by, for example, driving the second pressure adjustment mechanism 28 (increasing the valve opening and thus increasing the exhaust volume from the discharge section 27). If the internal pressure of the processing chamber 20 is less than the internal pressure of the generation chamber 10 (low pressure), in order to maintain this state, the internal pressure of the processing chamber 20 and the internal pressure of the generation chamber 10 may be maintained by, for example, keeping both the first pressure adjustment mechanism 18 and the second pressure adjustment mechanism 28 driven (maintaining the valve openings of both valves and thus maintaining the exhaust volume from the discharge sections 17 and 27).

[0022] When the internal pressure of the generation chamber 10 is P1 and the internal pressure of the processing chamber 20 is P2, the pressure difference P1-P2 is preferably 3 Pa or more and 1000 Pa or less, more preferably 30 Pa or more and 700 Pa or less, and even more preferably 50 Pa or more and 500 Pa or less. Within this range, the plasma generated in the generation chamber 10 can be suitably moved to the processing chamber 20 through the filter 30. In addition, the ratio of particles contained in the plasma moving to the processing chamber 20 (the ratio of highly attached particles to low attached particles, described later) can be set to a suitable range, and the coverage of the substrate W can be improved.

[0023] The processing chamber 20 includes a stage 40 on which a substrate W can be placed and which is in contact with the lower wall portion 21, and a second electrode portion 41 disposed inside the stage 40. The stage 40 has a protruding portion 40A that penetrates the lower wall portion 21 and protrudes downward. The second electrode portion 41 may also function as a chuck electrode that electrostatically attracts the substrate W placed on the stage 40 to the stage 40.

[0024] The plasma generation method in the processing chamber 20 is a capacitively coupled plasma (CCP) method. The plasma processing apparatus 100 includes a blocking capacitor 54 connected to the second electrode section 41 via a power supply line, a high-frequency power supply 55, and a ground 56. The power supply line connected to the second electrode section 41 passes through the inside of the protruding section 40A and is connected to the blocking capacitor 54. The upper wall section 11, which serves as the first electrode section, and the second electrode section 41 constitute a pair of parallel plate electrodes.

[0025] Power is supplied from the high-frequency power supply 55, and a high-frequency voltage of a predetermined frequency is applied to the second electrode section 41. This allows the processing chamber 20 to re-plasma (ionize) the plasma of the raw materials that have moved from the inside 10A of the generation chamber 10 through the holes 33 of the filter 30 to the inside 20A of the processing chamber 20, and accelerate it toward the substrate W. The frequency (application method) of the high-frequency voltage applied to the second electrode section 41 is not particularly limited, but from the viewpoint of suppressing reactions between raw materials and ionizing and accelerating the plasma, an application method in which a low frequency (e.g., 400 kHz) is mainly used with a high frequency (e.g., 13.56 MHz) superimposed, or a high-frequency pulse method in which a high frequency is applied intermittently, is preferred.

[0026] The filter 30 comprises a main body 32 and an end portion 31 located around the main body 32. The filter 30 is attached to and in contact with the side wall portion 15 of the generation chamber 10 and the side wall portion 22 of the processing chamber 20. These two side walls 15 and 22 may be connected in the Z direction, and the filter 30 may be attached to at least one of these two side walls 15 and 22.

[0027] As shown in Figures 1, 2A, and 2B, the filter 30 is located in the main body 32 and includes a plurality of holes 33 that penetrate in the Z direction so as to connect the interior 10A of the generation chamber 10 and the interior 20A of the processing chamber 20, and a heater 60 that heats the plurality of holes 33. On the other hand, as shown in Figure 1, the plasma processing apparatus 100 includes a detection unit 61 that detects the temperature of the holes 33 (more specifically, the temperature around the holes 33), and a control unit 50 that controls the heating temperature of the heater 60 that heats the area around the holes 33 to 100 degrees or higher, based on the temperature of the holes 33 detected by the detection unit 61.

[0028] The heating temperature of the holes 33 by the heater 60 can be changed as appropriate, but from the viewpoint of improving coverage and stabilizing coverage, it is preferably 100 degrees Celsius or more and 500 degrees Celsius or less, more preferably 150 degrees Celsius or more and 470 degrees Celsius or less, and even more preferably 250 degrees Celsius or more and 450 degrees Celsius or less. The method by which the control unit 50 controls the heater 60 is not particularly limited, but for example, the control unit 50 may perform heating with the heater 60 when the temperature of the holes 33 detected by the detection unit 61 falls below 100 degrees Celsius (a set temperature arbitrarily determined within the above heating temperature range), and stop heating with the heater 60 when it exceeds 100 degrees Celsius (the set temperature). The detection unit 61 is, for example, a thermocouple and is arranged near the filter 30. In Figure 1, the detection unit 61 is shown in a position in contact with the filter 30, but it is not limited to this.

[0029] The material of filter 30 contains 10 atm% or more of one or more materials from the group consisting of aluminum, silicon, yttrium, and carbon, relative to the total weight of the filter 30. Among these, aluminum is preferred as the material of filter 30 from the viewpoint of suitably processing the substrate. Furthermore, the material of filter 30 is said to have etching resistance to cleaning gas. The cleaning gas is not particularly limited, but examples include fluorine-based gases such as hydrogen fluoride, sulfur hexafluoride, ethane hexafluoride, and propane octafluoride. The cleaning gas is used, for example, when supplying it to the generation chamber 10 or processing chamber 20 after the substrate W has been treated with plasma to clean the insides 10A, 20A and filter 30.

[0030] Figure 2A is a schematic plan view of the filter 30 as seen from above. Figure 2B is a schematic cross-sectional view of the filter 30 (with multiple holes 33 omitted). As shown in Figures 2A and 2B, the main body 32 of the filter 30 has a circular shape in plan view. The end portion 31 of the filter 30 is located on the outside of the main body 32 in the planar direction and has an annular shape in plan view. The thickness of the main body 32 in the Z direction is thinner than that of the end portion 31.

[0031] Multiple holes 33 are arranged in parallel along the planar direction in the main body 32. The arrangement of the multiple holes 33 is not particularly limited, but the multiple holes 33 may be arranged so that they become sparser towards the outside (the number of holes 33 per unit area decreases as you approach the end 31) or so that they become denser towards the outside (the number of holes 33 per unit area increases as you approach the end 31) in the planar direction of the main body 32. A heater 60 is provided inside the end 31. The heater 60 is arranged in an annular shape along the end 31. When the end 31 is heated by the heater 60, heat is transferred from the end 31 to the main body 32, and the multiple holes 33 are heated.

[0032] Figure 3 is a schematic cross-sectional view showing how plasma particles S1 and S2 pass through the holes 33 (the heater 60 is shown near the holes 33 for convenience). As shown in Figure 3, the aspect ratio (L / D) of the holes 33, which is the value obtained by dividing the length (depth of the hole) L in the Z direction by the diameter (hole diameter) D, is between 1 and 10. From the viewpoint of suitably processing the substrate, the aspect ratio is preferably between 1 and 8, more preferably between 1 and 5, and even more preferably between 1.5 and 3. This aspect ratio may be the average aspect ratio. The average aspect ratio can be obtained, for example, by acquiring an SEM image of the cross-section of the filter 30, determining the aspect ratio for a plurality of holes 33 (e.g., 20 or more) arbitrarily selected from the image, and calculating the average value.

[0033] The diameter D of the holes 33 is between 0.5 mm and 2 mm. From the viewpoint of suitably processing the substrate, the diameter D of the holes 33 is preferably between 0.5 mm and 1.5 mm, and more preferably between 0.5 mm and 1.0 mm. This diameter D may be the average diameter. The average diameter can be determined, for example, by acquiring an SEM image of the cross-section of the filter 30, determining the diameter of a plurality of holes 33 (e.g., 20 or more) arbitrarily selected from the image, and calculating the average value.

[0034] The generation chamber 10 generates, as plasma, at least a first particle S1 and a second particle S2 that is less likely to adhere to the filter 30 than the first particle S1 (the particles of the generated plasma include at least a first particle S1 and a second particle S2 that is less likely to adhere to the filter 30 than the first particle S1). For each particle S1 and S2, the ease (or difficulty) of adhesion to the filter 30 can be determined by the adhesion coefficient of each particle S1 and S2. The adhesion coefficient can change depending on various conditions such as the surrounding environment including temperature and pressure, and the characteristics of the particle itself, but as an example, it can be estimated by the number of dangling bonds (unbonded bonds in the atom) that each particle S1 and S2 has. For a given particle, the more dangling bonds there are, the higher the adhesion coefficient and the easier it is to adhere to the filter 30 (these particles are called high-adhesion particles), and the fewer dangling bonds there are, the lower the adhesion coefficient and the more difficult it is to adhere to the filter 30 (these particles are called low-adhesion particles). The first particle S1 has a relatively larger number of dangling bonds than the second particle S2 and is considered a highly adherent particle. On the other hand, the second particle S2 has a relatively smaller number of dangling bonds than the first particle S1 and is considered a low-adhesion particle. In addition, the generation chamber 10 may be configured to generate three or more types of particles as plasma, in addition to the two particles S1 and S2 described above. The types of particles generated in the generation chamber 10 are appropriately changed, for example, depending on the type of raw material gas.

[0035] For example, when TEOS is used as the raw material for plasma, a high-frequency voltage is applied in the processing chamber 20, causing SiO to dissociate from TEOS, and SiO to oxidize and produce SiO2. At this time, since SiO2 has fewer dangling bonds than SiO, SiO2 corresponds to low-adhesion particles (second particle S2), and SiO corresponds to high-adhesion particles (first particle S1).

[0036] The filter 30 allows some of the particles contained in the plasma generated in the generation chamber 10 to pass through. In the filter 30, the first particles S1 adhere to the surface of the main body 32 (for example, the opening 33A that opens to the inside 10A side of the generation chamber 10 in the holes 33, or the side surface 33B) relatively more than the second particles S2, so the second particles S2 pass through the holes 33 relatively more than the first particles S1. The second particles S2 that have passed through the holes 33 are ionized again when high-frequency waves are applied inside the processing chamber 20A, and are deposited as a film F by being layered on the surface of the substrate W or in the trenches T.

[0037] The substrate W includes, for example, a semiconductor wafer such as a silicon substrate. The application of the substrate W is not particularly limited, but it may be for semiconductor devices or semiconductor memory components. The semiconductor memory component is not particularly limited, but an example is a 3D NAND flash memory.

[0038] [method] Next, the plasma treatment method will be explained. The plasma treatment method is performed, for example, as part of the process of manufacturing a semiconductor device from a substrate W.

[0039] As shown in Figure 1, the plasma processing method processes the substrate W with plasma generated using the plasma processing apparatus 100. More specifically, the plasma processing method includes a generation step of generating plasma from raw materials supplied from the upper wall 11 in a generation chamber 10 connected to the upper wall 11 as a raw material supply section; a passage step of passing some of the particles contained in the generated plasma through holes 33 of a filter 30 arranged between the generation chamber 10 and a processing chamber 20 adjacent to the generation chamber 10; and a processing step of processing the substrate W with plasma in the processing chamber 20.

[0040] In the generation process, raw material gas is supplied from the upper wall portion 11 to the interior 10A of the generation chamber 10, and power is supplied from the high-frequency power supply 52 to apply a high-frequency voltage of a predetermined frequency to the upper wall portion 11. This converts the raw material gas supplied to the interior 10A of the generation chamber 10 into plasma, thereby generating plasma of that raw material.

[0041] In the passing process, plasma of the raw material is passed through multiple holes 33 having an aspect ratio of 1 to 10 and a diameter of 0.5 mm to 2 mm. The passing process also includes a heating process in which the multiple holes 33 are heated by a heater 60.

[0042] Furthermore, the passing process may include a pressure adjustment step in which at least one of the first pressure adjustment mechanism 18 and the second pressure adjustment mechanism 28 is driven to adjust the pressure so that the processing chamber 20 is at a lower pressure than the generation chamber 10. The passing process may also include an acceleration step in which power is supplied from a high-frequency power supply 55 and a high-frequency voltage of a predetermined frequency is applied to the second electrode section 41 to re-plasma (ionize) the plasma of the raw material that has moved from the inside 10A of the generation chamber 10 through the holes 33 of the filter 30 to the inside 20A of the processing chamber 20, and accelerate it toward the substrate W side.

[0043] In the processing step, plasma (mainly second particles S2) that has passed through the holes 33 is deposited onto the surface and grooves T of the substrate W to form a film F.

[0044] [effect] Conventional methods for processing substrates include ALD (atomic layer deposition), thermal CVD, and plasma CVD. However, ALD and thermal CVD have relatively low deposition rates and throughput. While thermal CVD has a higher throughput than ALD, it requires high substrate temperatures, making it unsuitable for heat-sensitive devices. On the other hand, plasma CVD offers higher deposition rates and lower temperatures compared to ALD and thermal CVD, but it has poor coverage (step coverage), making it unsuitable for deposition on substrates with high aspect ratio structures, for example.

[0045] As shown in Figures 1 to 3, the plasma processing apparatus 100 according to this embodiment comprises a generation chamber 10 connected to a raw material supply unit 11 and generating plasma from raw materials supplied from the raw material supply unit 11; a processing chamber 20 adjacent to the generation chamber 10 and where a substrate W is placed; and a filter 30 placed between the generation chamber 10 and the processing chamber 20 and allowing some of the particles contained in the generated plasma to pass through. The filter 30 has holes 33 connected to the generation chamber 10 and the processing chamber 20.

[0046] With this configuration, highly adhering particles that easily adhere to the filter 30 can be deposited onto the filter 30 from the plasma generated in the generation chamber 10, while less adhering particles that do not easily adhere to the filter 30 can be passed through the holes 33 and moved to the processing chamber 20, thereby improving coverage. Furthermore, since the configuration of the holes 33 in the filter 30 (number, diameter, depth, etc.) can be changed as appropriate, the ratio of highly adhering particles to less adhering particles (referred to as the particle ratio) that move to the processing chamber 20 from the plasma can be adjusted, thereby adjusting the coverage. In addition, it is possible to suppress variations in the characteristics of the substrate W after processing from lot to lot or in parts of the substrate surface, and maintain those characteristics (stabilization of coverage). Moreover, since the substrate W is processed with plasma, the substrate W can be processed at a higher speed compared to conventional ALD or thermal CVD processes, improving productivity and making it possible to apply this technology to a wide range of film types and gas systems (raw materials). In this way, it is possible to provide a plasma processing apparatus 100 that can suitably process the substrate W.

[0047] Here, if plasma particles adhere to the pores of the filter and clog them, it becomes difficult for particles to pass through the pores, and the filter performance deteriorates (this is called pore clogging). This raises concerns about reduced coverage and variations in the characteristics of the substrate after processing, either from lot to lot or in parts of the substrate surface. However, since the filter 30 of this embodiment is equipped with a heater 60 that heats the pores 33, the increase in the adhesion coefficient of plasma particles caused by the lowering of the temperature of the pores 33 can be suppressed by heating the pores 33 with the heater 60, thereby suppressing an excessive increase in the film deposition rate in the pores 33 and preventing pore clogging. This makes it possible to stabilize coverage.

[0048] Furthermore, in this embodiment, the pores 33 of the filter 30 have an aspect ratio of 1 to 10. With this configuration, coverage can be further improved. Also, in this embodiment, the pore diameter D of the pores 33 is 0.5 mm to 2 mm. With this configuration, regarding the lower limit of the pore diameter D, clogging can be suppressed and coverage can be stabilized. Furthermore, regarding the upper limit of the pore diameter D, abnormal discharge can be suppressed.

[0049] Furthermore, in this embodiment, the generation chamber 10 is configured to generate first particles S1 and second particles S2 which are less likely to adhere to the filter 30 than the first particles S1 as plasma, and the filter 30 is configured such that, as the first particles S1 adhere, relatively more second particles S2 pass through the holes 33. With such a configuration, it is possible to provide a practical plasma processing apparatus 100 with improved coverage.

[0050] Furthermore, in this embodiment, the plasma processing apparatus 100 is equipped with pressure adjustment mechanisms 18 and 28 that adjust the pressure so that the processing chamber 20 is at a lower pressure than the generation chamber 10. With this configuration, the flow rate of plasma particles passing through the holes 33 of the filter 30 can be increased, making it possible to improve the processing speed (film deposition speed) of the substrate W. In addition, since the flow rate of plasma particles passing through the holes 33 of the filter 30 can be controlled by the pressure adjustment mechanisms 18 and 28, it is possible to adjust or stabilize the coverage.

[0051] Here, the plasma particles after passing through the filter move in an undirected (random) state and are deposited conformally (uniformly) on the substrate W. Therefore, in the process of depositing films into trenches, voids are easily created, for example, when the sides or openings of the trenches become blocked. Also, as the aspect ratio of the trench increases, it becomes more difficult for the raw material to reach the bottom of the trench, making voids more likely to occur (this is also true for film deposition by ALD and thermal CVD).

[0052] In this embodiment, the generation chamber 10 is equipped with a first electrode section 11 and is configured to generate plasma by applying a high-frequency voltage to the first electrode section 11, and the processing chamber 20 is equipped with a second electrode section 41 and is configured to accelerate the plasma that has passed through the hole 33 toward the substrate W by applying a high-frequency voltage to the second electrode section 41.

[0053] With this configuration, the plasma particles after passing through the filter 30 can be directed toward the substrate W. As a result, deposition near the bottom of the groove can occur faster than deposition near the opening (inlet), allowing the bottom of the groove to rise more quickly (promoting bottom-up growth). This reduces the voids that form in the groove and improves the ability to fill the groove. Furthermore, it is possible to improve the ability to fill grooves with relatively high aspect ratios. In addition, by providing such directivity, it is possible to further improve coverage.

[0054] Furthermore, in this embodiment, the plasma processing apparatus 100 includes a detection unit 61 for detecting the temperature of the holes 33, and a control unit 50 that controls the heating temperature of the heater 60 to be 100 degrees or higher based on the temperature of the holes 33 detected by the detection unit 61. With this configuration, the particle ratio can be suitably adjusted, and the coverage can be suitably adjusted. In addition, the coverage can be made more stable.

[0055] Furthermore, in this embodiment, the raw material supply section (upper wall section 11) includes a shower head. With this configuration, it is possible to provide a practical plasma processing apparatus 100.

[0056] Furthermore, in this embodiment, the material of the filter 30 contains 10 atm% or more of one or more materials from the group consisting of aluminum, silicon, yttrium, and carbon, and has etching resistance to cleaning gas. With such a configuration, it is possible to provide a practical plasma processing apparatus 100.

[0057] Furthermore, the plasma treatment method according to this embodiment treats the substrate W with plasma generated using the plasma treatment apparatus 100 described above. By following such a process, it is possible to obtain a plasma treatment method that can suitably treat the substrate W while enjoying the effects described above.

[0058] [Second Embodiment] The configuration of the filter 30 and heater 60 according to the first embodiment can be adjusted as appropriate. Below, as a second embodiment, a filter 230 and heater 260, which have a different configuration from the filter 30 and heater 60, will be described.

[0059] Figure 4A is a schematic plan view of the filter 230 as seen from above. Figure 4B is a schematic cross-sectional view of the filter 230 (with the multiple holes 233 omitted). As shown in Figures 4A and 4B, the filter 230 has multiple heaters 260 provided on the annular end portion 231, which is located outside the main body portion 232 in the planar direction. The multiple heaters 260 are arranged along the circumferential direction of the end portion 231, with predetermined intervals between them. The heaters 260 are rod-shaped, extending radially from the center outward in the planar direction of the filter 230. Part of the heater 260 is inside the end portion 231, and the other part protrudes outside the end portion 231.

[0060] With this configuration, the multiple holes 233 arranged in the main body 232 can be suitably heated by the heater 260, and uneven heating in the main body 232 can be suppressed.

[0061] [Third Embodiment] The configurations of the generation chamber 10 and processing chamber 20 according to the first embodiment can be adjusted as appropriate. Below, a third embodiment will be described, consisting of a generation chamber 310 and a processing chamber 320, which have a different configuration from the generation chamber 10 and processing chamber 20.

[0062] Figure 5 is a schematic cross-sectional view of a plasma processing apparatus according to the third embodiment. As shown in Figure 5, the plasma processing apparatus 300 comprises a generation chamber 310 for generating raw material plasma, a processing chamber 320 adjacent to the generation chamber 310 and contained within the interior 310A of the generation chamber 310, in which the substrate W is placed, and a filter 330 disposed between the generation chamber 310 and the processing chamber 320.

[0063] The generation chamber 310 comprises an upper wall portion 11, a side wall portion 315 connected to the planar end of the upper wall portion 11 and extending in the Z direction below the upper wall portion 11, and a lower wall portion 319 connected to the lower end of the side wall portion 315 and extending in the planar direction. The interior 310A of the generation chamber 310 is the space between the generation chamber 310 and the processing chamber 320, and is a space partitioned by the filter 330, the upper wall portion 11, the side wall portion 315, the lower wall portion 319, and the side wall portion 322 of the processing chamber.

[0064] The side wall portion 315 is longer in the Z direction than the side wall portion 322 of the processing chamber. The lower wall portion 319 is equipped with an outlet portion 327 for discharging gas and other substances from the inside 310A of the generation chamber 310 to the outside. The side wall portion 315 and the lower wall portion 319 are made of an insulator made of a material such as aluminum oxide. The plasma generation method in the generation chamber 310 is a capacitively coupled plasma (CCP) method.

[0065] The processing chamber 320 includes a side wall portion 322 extending in the Z direction above the stage 340. The interior 320A of the processing chamber 320 is the space between the filter 330 and the stage 340, and is a space partitioned by the filter 330, the stage 340, and the side wall portion 322.

[0066] Stage 340 is electrically connected to and grounded to earth 357. Stage 340 includes a substrate heater 365 for heating the substrate W. The temperature at which the substrate W is heated by the substrate heater 365 is not particularly limited, but from the viewpoint of improving embedding and coverage, it is preferably 100 degrees or higher, more preferably 200 degrees or higher, and even more preferably 250 degrees or higher.

[0067] The filter 330 has a plurality of holes 333 that penetrate in the Z direction so as to connect the interior 310A of the generation chamber 310 and the interior 320A of the processing chamber 320. The filter 330 may also be equipped with a heater for heating the plurality of holes 333.

[0068] With this configuration, the plasma of the raw materials generated in the generation chamber 310 diffuses through the pores 333 of the filter 330 and is deposited on the surface of the substrate W.

[0069] Figure 6 shows SEM images illustrating the changes in voids in grooves T (see Figure 3) after plasma deposition on a substrate W under various conditions. The various conditions include using TEOS or SiH4 as the plasma raw material, a configuration without filter 330 (indicated as "without filter"), or a configuration with filter 330 installed (indicated as "with filter"), as in this embodiment. In all cases, the internal pressure of the inside 310A of the generation chamber 310 is 100 Pa. The hole diameter of hole 333 is 0.5 mm, and the aspect ratio is 2.

[0070] As shown in Figure 6, when TEOS is used as the plasma raw material, the void V2 under conditions with a filter tends to be smaller than the void V1 under conditions without a filter. Specifically, both the length in the horizontal direction (corresponding to the X direction) and the length in the vertical direction (corresponding to the Z direction) tend to be smaller. Similarly, when SiH4 is used as the plasma raw material, the void V4 under conditions with a filter tends to be smaller than the void V3 under conditions without a filter. Specifically, both the length in the horizontal direction and the length in the vertical direction tend to be smaller. Thus, the plasma processing apparatus 300 equipped with the filter 330 makes it possible to improve the coverage and embedding of the substrate W.

[0071] Furthermore, the stage 340 is equipped with a substrate heater 365 for heating the substrate W. Here, Figure 7 shows SEM images illustrating the changes in voids formed in the grooves T (see Figure 3) after plasma deposition treatment is performed on the substrate W under various conditions. The various conditions include using TEOS as the plasma raw material and, in the configuration with the filter 330 attached as in this embodiment, heating the substrate W to 250 degrees and 350 degrees using the substrate heater 365. In all cases, the internal pressure of the inside 310A of the generation chamber 310 is 100 Pa. The hole diameter of the hole 333 is 0.5 mm and the aspect ratio is 2.

[0072] As shown in Figure 7, when the temperature at which the substrate W is heated by the substrate heater 365 is increased from 250 degrees to 350 degrees, it can be seen that the void V6 under the heating temperature condition tends to become smaller than the void V5 under the heating temperature condition of 250 degrees. Specifically, both the length in the left-right direction of the paper (corresponding to the X direction) and the length in the up-down direction of the paper (corresponding to the Z direction) tend to decrease. Thus, the plasma processing apparatus 300 equipped with a substrate heater 365 for heating the substrate W makes it possible to improve the coverage and embedding of the substrate W.

[0073] [Other embodiments] The plasma processing apparatus according to the first to third embodiments has been described above. However, these configurations are merely examples, and the specific configuration can be adjusted as appropriate.

[0074] For example, in the above embodiment, the upper wall of the production chamber is the raw material supply section and the first electrode section. However, the raw material supply section may be located on the side wall of the production chamber, and the first electrode section may be located on the upper wall of the production chamber as a component different from the raw material supply section.

[0075] Furthermore, in the above embodiment 1, for example, a configuration was shown in which the high-frequency power supply and ground were electrically connected to the upper wall portion as the first electrode portion, and the high-frequency power supply and ground were electrically connected to the second electrode portion. However, the members to which the high-frequency power supply and ground are connected can be changed as appropriate. The plasma processing apparatus only needs to be configured such that the high-frequency power supply and ground are connected to specific members so that plasma can be generated from raw materials in at least the generation chamber.

[0076] Furthermore, the state of the plasma particles as they pass through the filter holes is not particularly limited. For example, the plasma particles passing through the filter holes may consist of one or more types, such as ionic particles, radical particles, and neutral particles.

[0077] [others] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0078] 10, 310...Generation chamber, 11...Upper wall section (raw material supply section, first electrode section), 18, 28...Pressure adjustment mechanism, 20, 320...Processing chamber, 30, 230, 330...Filter, 33, 233, 333...Holes, 41...Second electrode section, 50...Control section, 60, 260...Heater, 61...Detection section, 100, 300...Plasma processing apparatus, F...Film, S1...First particle, S2...Second particle, W...Substrate.

Claims

1. A generation chamber connected to a raw material supply unit, which generates plasma from the raw material supplied from the raw material supply unit, Adjacent to the aforementioned generation chamber is a processing chamber in which the substrate is placed, The system includes a filter positioned between the generation chamber and the processing chamber, which allows some of the particles contained in the generated plasma to pass through, The aforementioned filter is The hole connecting the generation chamber and the processing chamber, A plasma processing apparatus comprising a heater for heating the aforementioned holes.

2. A generation chamber connected to a raw material supply unit, which generates plasma from the raw material supplied from the raw material supply unit, Adjacent to the aforementioned generation chamber is a processing chamber in which the substrate is placed, The system includes a filter positioned between the generation chamber and the processing chamber, which allows some of the particles contained in the generated plasma to pass through, The plasma processing apparatus comprises a filter connected to the generation chamber and the processing chamber, having an aspect ratio of 1 or more and holes with a diameter of 0.5 mm or more and 2 mm or less.

3. The particles include at least a first particle and a second particle that is less likely to adhere to the filter than the first particle. The generation chamber is configured to generate at least the first and second particles as the plasma. The plasma processing apparatus according to claim 1 or 2, wherein the filter is configured such that the second particles pass through the holes more frequently when the first particles adhere to it.

4. The plasma processing apparatus according to claim 1 or 2, further comprising a pressure adjustment mechanism for adjusting the pressure so that the processing chamber is at a lower pressure than the generation chamber.

5. The generation chamber is equipped with a first electrode section, and is configured to generate the plasma by applying a high-frequency voltage to the first electrode section. The plasma processing apparatus according to claim 1 or 2, wherein the processing chamber comprises a second electrode section, and the plasma passing through the hole is accelerated toward the substrate side by applying a high-frequency voltage to the second electrode section.

6. A heater for heating the aforementioned holes, A detection unit for detecting the temperature of the hole, A plasma processing apparatus according to claim 1 or 2, comprising: a control unit that controls the heating temperature of the heater to be 100 degrees or higher based on the temperature of the hole detected by the detection unit.

7. The plasma processing apparatus according to claim 1 or 2, wherein the raw material supply unit includes a shower head.

8. The plasma processing apparatus according to claim 1 or 2, wherein the material of the filter contains 10 atm% or more of one or more of the group consisting of aluminum, silicon, yttrium, and carbon, and has etching resistance to cleaning gas.

9. A generation process in a generation chamber connected to a raw material supply unit, in which plasma of raw materials supplied from the raw material supply unit is generated, A passing process is performed in which some of the particles contained in the generated plasma are passed through the holes of a filter placed between the generation chamber and the processing chamber adjacent to the generation chamber. The process includes a process of processing the substrate with the plasma in the processing chamber, A plasma treatment method in which the hole is heated during the passing process.

10. A generation process in a generation chamber connected to a raw material supply unit, in which plasma of raw materials supplied from the raw material supply unit is generated, A passing process is performed in which some of the particles contained in the generated plasma are passed through the holes of a filter placed between the generation chamber and the processing chamber adjacent to the generation chamber. The process includes a process of processing the substrate with the plasma in the processing chamber, A plasma treatment method comprising passing the plasma through a hole having an aspect ratio of 1 or more and 10 or less, and a diameter of 0.5 mm or more and 2 mm or less, in the aforementioned passing step.

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