SUBSTRATE PROCESSING APPARATUS AND METHOD FOR PRODUCING SEMICONDUCTOR DEVICE - Patent application

Abstract

To provide a substrate processing device and a method of manufacturing a semiconductor device capable of realizing a high throughput in substrate processing using a plasma.SOLUTION: A plasma processing unit 410 used as a processing chamber has: a reaction container 431; a resonance coil 432 provided on a side wall outer periphery of the reaction container; a gas introduction port 433 provided on a container upper end surface inside the reaction container; a gas passage between a top plate 454 and a first baffle plate 460a, in the reaction container; a first gap formed between an outer edge of an upper end of the gas passage and an inner peripheral surface of the reaction container so as to surround the outer edge of the upper end of the gas passage; and a second gap formed between an outer edge of a lower end of the gas passage and the inner peripheral surface of the reaction container so as to surround the outer edge of the lower end of the gas passage. A distance between the upper end of the gas passage and the lower end of the gas passage is longer than a width of the first and second gaps.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a substrate processing apparatus that generates plasma and processes a substrate with the plasma, and a method for manufacturing a semiconductor device. [Background technology]

[0002] When manufacturing semiconductor devices, various processes are carried out using plasma. One method for generating plasma is the so-called inductive coupling method (ICP (Inductive Coupling Plasma) method). In the ICP method, high-frequency power is supplied to a coil to create an electric field in the plasma generation space, and the gas supplied to that space is turned into a plasma state. An example of an ICP type substrate processing apparatus is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-77893 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional substrate processing apparatuses, it is difficult to generate a high-density plasma, resulting in a problem of low throughput in substrate processing.

[0005] An object of the present invention is to provide a substrate processing apparatus and a method for manufacturing a semiconductor device that are capable of performing substrate processing with high throughput in substrate processing using plasma. [Means for solving the problem]

[0006] The present invention relates to A reaction vessel; A coil provided on the outer periphery of the side wall of the reaction vessel; a gas inlet provided on an upper end surface of the reaction vessel inside the reaction vessel; a gas flow path forming portion provided in the reaction vessel between the gas inlet and an upper end of the coil, the gas flow path forming portion having an opposing surface facing the upper end surface of the vessel; a first gap formed between an outer edge of an upper end of the gas flow channel forming portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the upper end of the gas flow channel forming portion; a second gap formed between an outer edge of a lower end of the gas flow channel forming portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the lower end of the gas flow channel forming portion; having A distance between an upper end of the gas flow passage forming portion and a lower end of the gas flow passage forming portion is greater than a width of the first gap and a width of the second gap. Provide technology. Effect of the Invention

[0007] According to the present invention, substrate processing with high throughput can be performed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view for explaining an ashing device according to a preferred embodiment of the present invention. [Diagram 2] 1 is a schematic vertical sectional view for explaining an ashing device according to a preferred embodiment of the present invention. [Diagram 3] 1 is a vertical sectional view for explaining a plasma processing unit of an ashing apparatus according to a preferred embodiment of the present invention. [Figure 4] 3 is a vertical sectional view illustrating a baffle plate of a plasma processing unit of the ashing apparatus according to the preferred embodiment of the present invention. FIG. [Diagram 5] 4 is a vertical sectional view for explaining a mounting structure of a baffle plate of a plasma processing unit provided in an ashing apparatus according to a preferred embodiment of the present invention. FIG. [Figure 6]4 is a vertical cross-sectional view for explaining a gas flow rate in a plasma processing unit of the ashing apparatus according to the preferred embodiment of the present invention. FIG. [Figure 7] FIG. 2 is an explanatory diagram for explaining a normal discharge limit power. [Figure 8] 4 shows a process flow in a plasma processing unit of the ashing apparatus according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, preferred embodiments of the present invention will be described with reference to the drawings. The present invention relates to a substrate processing method used in, for example, semiconductor manufacturing equipment, and in particular to a dry ashing process in which a reactive gas is turned into a plasma state by an ICP method, and a predetermined organic thin film (resist, resist film) on the substrate surface is stripped off by the highly reactive reactive species (reactive active species) obtained thereby.

[0010] In a preferred embodiment of the present invention, a semiconductor device manufacturing method and a substrate processing method are realized by an ashing apparatus used as a semiconductor manufacturing apparatus and a substrate processing apparatus. Fig. 1 is a schematic cross-sectional view for explaining an ashing apparatus according to a preferred embodiment of the present invention, and Fig. 2 is a schematic vertical cross-sectional view for explaining an ashing apparatus according to a preferred embodiment of the present invention. As shown in Fig. 1 and Fig. 2, the ashing apparatus 10 includes an EFEM (Equipment Front End Module) 100, a load lock chamber section 200, a transfer module section 300, and a process chamber section 400 used as a processing chamber in which an ashing process is performed.

[0011] The EFEM 100 includes front opening unified pods (FOUPs) 110 and 120 and an atmospheric robot 130 that is a first transfer unit that transfers wafers from each FOUP to a load lock chamber. The FOUP holds 25 wafers, and the arm of the atmospheric robot 130 extracts five wafers at a time from the FOUP.

[0012] The load lock chamber section 200 includes load lock chambers 250, 260, and buffer units 210, 220 that hold wafers 600 transferred from a FOUP in the load lock chambers 250, 260, respectively. The buffer units 210, 220 include boats 211, 221 and index assemblies 212, 222 disposed thereunder. The boat 211 and the index assembly 212 disposed thereunder rotate simultaneously on a θ-axis 214. Similarly, the boat 221 and the index assembly 222 disposed thereunder rotate simultaneously on a θ-axis 224.

[0013] The transfer module section 300 includes a transfer module 310 used as a transfer chamber, and the above-mentioned load lock chambers 250 and 260 are attached to the transfer module 310 via gate valves 311 and 312. The transfer module 310 is provided with a vacuum arm robot unit 320 used as a second transfer section.

[0014] The process chamber section 400 includes plasma processing units 410 and 420 used as processing chambers, and plasma generation chambers 430 and 440 provided above the plasma processing units 410 and 420. The plasma processing units 410 and 420 are attached to a transfer module 310 via gate valves 313 and 314.

[0015] The plasma processing units 410, 420 include susceptor tables 411, 421 on which a wafer 600 is placed. Lifter pins 413, 423 are provided penetrating the susceptor tables 411, 421, respectively. The lifter pins 413, 423 move up and down in the directions of Z axes 412, 422, respectively.

[0016] The plasma generation chambers 430 and 440 include reaction vessels 431 and 441, respectively. A resonant coil, which will be described later, is provided outside the reaction vessels 431 and 441. High-frequency power is applied to the resonant coil to convert a reactive gas for ashing processing introduced from a gas inlet, which will be described later, into a plasma state. The plasma is used to ash (plasma process) the resist on the wafer 600 placed on the susceptor tables 411 and 421.

[0017] Furthermore, the system includes a controller 500 electrically connected to each of the components. The controller 500 controls the operation of each of the components.

[0018] In the ashing apparatus 10 configured as above, wafers 600 are transported from the FOUPs 110 and 120 to the load lock chambers 250 and 260, respectively. At this time, first, as shown in Fig. 2, the atmospheric robot 130 stores the tweezers in the pod of the FOUP and places five wafers on the tweezers. At this time, the tweezers and arm of the atmospheric robot are raised and lowered to match the height position of the wafers to be removed. After the wafers are placed on the tweezers, the atmospheric transfer robot 130 rotates in the direction of the θ-axis 131, and loads the wafers onto the boats 211, 221 of the buffer units 210, 220, respectively. At this time, the boats 211, 221 move in the direction of the Z-axis 230, and the boats 211, 221 each receive 25 wafers 600 from the atmospheric transfer robot 130. After receiving the 25 wafers, the boats 211, 221 are each moved in the direction of the Z-axis 230 so that the wafers at the bottom of the boats 211, 221 are aligned with the height position of the transfer module section 300.

[0019] In the load lock chambers 250, 260, the wafer 600 held by the buffer units 210, 220 in the load lock chambers 250, 260, respectively, is loaded onto the fingers 321 of the vacuum arm robot unit 320. The vacuum arm robot unit 320 is rotated in the direction of the θ-axis 325, and the fingers are further extended in the direction of the Y-axis 326, and the wafer 600 is transferred onto the susceptor tables 411, 421 in the plasma processing units 410, 420, respectively.

[0020] Here, the operation of the ashing apparatus 10 when transferring the wafer 600 from the fingers 321 to the susceptor tables 411, 421 will be described.

[0021] The fingers 321 and lifter pins 413, 423 of the vacuum arm robot unit 320 cooperate to transfer the wafer 600 onto the susceptor tables 411, 421, respectively. In addition, by performing the reverse operation, the vacuum arm robot unit 320 transfers the wafer 600, after processing, from the susceptor tables 411, 421 to the buffer units 210, 220 in the load lock chambers 250, 260, respectively.

[0022] 3 is a diagram showing details of the plasma processing unit 410. The above-mentioned plasma processing unit 420 has the same configuration as the plasma processing unit 410. Moreover, the above-mentioned susceptor table 421 included in the plasma processing unit 420 has the same configuration as the susceptor table 411.

[0023] The plasma processing unit 410 is an ICP type plasma processing unit that performs ashing on a semiconductor substrate or a semiconductor element by dry processing. As shown in FIG. 3, the plasma processing unit 410 includes a plasma generation chamber 430 for generating plasma, a processing chamber 445 for accommodating a wafer 600 such as a semiconductor substrate, a high frequency power supply 444 for supplying high frequency power to the plasma generation chamber 430 (particularly the resonant coil 432), and a frequency matching device 446 for controlling the oscillation frequency of the high frequency power supply 444. For example, the plasma generation chamber 430 is disposed on the top of a horizontal base plate 448 as a stand, and the processing chamber 445 is disposed below the base plate 448. The resonant coil 432 and the outer shield 452 form a helical resonator.

[0024] The plasma generation chamber 430 is configured to be depressurized and supplied with a reactive gas for plasma, and is composed of a reaction vessel 431, a resonant coil 432 wound around the outer periphery of the reaction vessel, and an outer shield 452 arranged around the outer periphery of the resonant coil 432 and electrically grounded.

[0025] The reaction vessel 431 is a so-called chamber formed in a cylindrical shape from high-purity quartz glass or ceramics. The reaction vessel 431 is disposed so that its axis is vertical, and its upper and lower ends are airtightly sealed by a top plate 454 and a processing chamber 445 provided in a different direction from the top plate 454. The top plate 454 is supported by the flange 431 b of the reaction vessel 431 and the upper end of the outer shield 452 .

[0026] The top plate 454 has a lid portion 454a that closes one end of the reaction vessel 431 and a support portion 454b that supports the lid portion 454a. The lid portion 454a is a surface on the radial inner side from a portion that contacts the tip portion 431a, and the support portion 454b is a portion that is supported by the flange 431b and the outer shield 452. A gas inlet 433 is provided at approximately the center of the lid portion 454a. An O-ring 453 is provided between the outer periphery of the tip portion 431a, the flange 431b, and the support portion 454b, so as to make the plasma generation chamber 430 airtight.

[0027] A susceptor 459 supported by a plurality of (for example, four) pillars 461 is provided on the bottom surface of the processing chamber 445 below the reaction vessel 431. The susceptor 459 is provided with a susceptor table 411 and a heater 463 as a substrate heating unit that heats the wafer on the susceptor. An exhaust plate 465 is disposed below the susceptor 459. The exhaust plate 465 is supported by a bottom plate 469 via a guide shaft 467, and the bottom plate 469 is airtightly disposed on the lower surface of the processing chamber 445. A lift plate 471 is disposed so as to be able to move up and down freely using the guide shaft 467 as a guide. The lift plate 471 supports at least three lifter pins 413.

[0028] 3, the lifter pins 413 penetrate the susceptor table 411 of the susceptor 459. A support portion 414 for supporting a wafer 600 is provided on the top of the lifter pins 413. The support portion 414 extends toward the center of the susceptor 459. By raising and lowering the lifter pins 413, the wafer 600 can be placed on the susceptor table 411 or lifted up from the susceptor table 411. A lift shaft 473 of a lift drive unit (not shown) is connected to the lift plate 471 via the bottom plate 469. When the lift drive unit raises and lowers the lift shaft 473, the support unit 414 rises and lowers via the lift plate 471 and the lifter pin 413. In addition, in FIG. 3, the lifter pin 413 is shown in a state in which the support portion 414 is attached.

[0029] A baffle ring 458 is provided between the susceptor 459 and the exhaust plate 465. A first exhaust chamber 474 is formed by the baffle ring 458, the susceptor 459, and the exhaust plate 465. The cylindrical baffle ring 458 has a large number of vent holes evenly arranged therein. Therefore, the first exhaust chamber 474 is separated from the processing space of the processing chamber 445. The first exhaust chamber 474 is also in communication with the processing space by the vent holes. The processing space refers to a space in which a substrate is processed.

[0030] An exhaust communication hole 475 is provided in the exhaust plate 465. The first exhaust chamber 474 and the second exhaust chamber 476 are connected to each other through the exhaust communication hole 475. An exhaust pipe 480 is connected to the second exhaust chamber 476, and a pressure adjustment valve 479 and an exhaust pump 481 are provided in the exhaust pipe 480 from the upstream side. The gas exhaust unit is composed of the exhaust pipe 480, the pressure adjustment valve 479, and the exhaust pump 481. The gas exhaust unit is connected to the processing chamber 445 via the second exhaust chamber 476.

[0031] A gas supply pipe 455 extending from a gas supply unit 482 and for supplying a required reactive gas for plasma is attached to a gas inlet 433 in a top plate 454 at the top of the reaction vessel 431. The gas inlet 433 is conical, and the diameter increases toward the processing chamber. The gas supply unit 482 (gas supply section) has, in order from the upstream side, a gas source 483, a mass flow controller 477 which is a flow rate control section, and an on-off valve 478. The gas supply unit 482 controls the amount of gas supplied by controlling the mass flow controller 477 and the on-off valve 478.

[0032] Furthermore, the supply amount and exhaust amount are adjusted by the mass flow controller 477 and the pressure adjustment valve 479, whereby the pressure in the processing chamber 445 is adjusted.

[0033] Fig. 4(a) shows the periphery of a baffle plate 460 according to a preferred embodiment of the present invention, while Fig. 4(b) shows the periphery of a baffle plate 460 according to a comparative example.

[0034] As shown in FIG. 4(a), the baffle plate 460 according to the preferred embodiment of the present invention is composed of a first baffle plate 460a made of, for example, quartz, and a second baffle plate 460b. The first baffle plate 460a is provided in the reaction vessel 431 between the upper end of the resonance coil 432 and the gas inlet 433. The second baffle plate 460b is provided between the first baffle plate 460a and the upper end of the resonance coil 432. That is, the first baffle plate 460a and the second baffle plate 460b are provided so as to overlap with each other with a space therebetween between the upper end of the resonance coil 432 and the gas inlet 433. The first baffle plate 460a and the second baffle plate 460b are provided between the susceptor table 411 and the gas inlet 433.

[0035] Moreover, the first baffle plate 460a and the second baffle plate 460b have substantially the same shape and are plate shapes without holes. Also, they are shaped to fit the inner circumference of the reaction vessel 431. That is, if the inner circumference of the reaction vessel 431 is circular, the ends of the baffle plates are also circular. In other words, the baffle plates are disk-shaped to fit the inner circumference of the reaction vessel 431.

[0036] With this configuration, a gas flow path is formed between the top plate 454 and the first baffle plate 460a, and a gas flow path is formed along the inner circumference of the reaction vessel 431 between the end of the reaction vessel 431 and the baffle plate. Since the gas supplied from the gas inlet 433 is supplied via each gas flow path, the gas supplied does not concentrate in the center of the reaction vessel 431. That is, since the gas is supplied via the first baffle plate 460a and the second baffle plate 460b, a gas flow is formed as shown by the dashed arrow in FIG. 4(a), and the gas falls approximately vertically near the upper end of the resonance coil 432 (line AA in FIG. 4(a)). Therefore, there is no gas loss.

[0037] On the other hand, the baffle plate 460 according to the comparative example is composed of one baffle plate 460, as shown in Fig. 4(b). In the baffle plate 460 according to the comparative example, as shown by the dashed arrow in Fig. 4(b), a gas flow path is formed obliquely from the gas inlet 433 toward the outer periphery of the baffle plate 460, and the gas is diffused near the upper end of the resonance coil 432 (line AA in Fig. 4(b)). In other words, the gas is diffused to an area with a weak electric field strength, which leads to weak plasma generation.

[0038] Here, in the case of an ICP type plasma generation device, it is known that the electric field for generating plasma is stronger closer to the resonance coil 432. Therefore, by concentrating gas in a place with a strong electric field, that is, a place close to the resonance coil 432, it is possible to increase the plasma generation efficiency. Also, in such a place, plasma with high energy and long life is generated. That is, by providing at least two baffle plates 460a and 460b, the gas flows along the inner wall of reaction vessel 431 close to the resonant coil as shown by the arrows, and the gas is concentrated in a place with a strong electric field, that is, in a place close to resonant coil 432, thereby increasing the plasma generation efficiency. Also, in such a place, a plasma with high energy and long life is generated.

[0039] Next, the mounting structure of the baffle plates 460a, 460b will be described with reference to FIG. FIG. 5 is an enlarged view of the baffle plates 460a, 460b and the top plate 454, and is a view for explaining the mounting structure of the baffle plates 460a, 460b. First, the fixing mechanism will be described with reference to FIG. A bolt 491 inserted into the top plate 454 is successively inserted into a first collar 492 having a hole in the center, a fixing hole provided in the first baffle plate 460a, a second collar 493 having a hole in the center, and a fixing hole provided in the second baffle plate 460b, and fixed with a fixing bolt 494. The first collar 492 is made of metal (eg, aluminum alloy) and is configured so that the top plate 454 and the collar 492 are grounded. The fixing mechanisms are provided at least three positions evenly spaced around the circumference of the baffle plate 460.

[0040] Next, the positional relationship between the baffle plates 460a and 460b, the top plate 454, and the reaction vessel 431 will be described with reference to FIG. 5(b). 5(b), the distance between the lid portion 454a of the top plate 454 and the surface of the first baffle plate 460a facing the lid portion 454a is defined as GAP(a). GAP(a) is set to 1 mm to 5 mm, and more preferably 2 mm to 4 mm. The distance between the opposing surfaces of the first baffle plate 460a and the second baffle plate 460b is defined as GAP(b), which is set to 30 mm to 50 mm. The distance between the diameter of the baffle plate 460 and the reaction vessel is set to 0.1 to 10 mm. Specifically, the baffle plate is set to 269 mm, which is smaller than the diameter of the substrate, and the inner circumference of the reaction vessel 431 is set to 275 mm.

[0041] The distance between first baffle plate 460a and gas inlet 433 is set to a distance that prevents abnormal discharge from occurring between first baffle plate 460a and lid portion 454a, and is particularly set to a distance that prevents abnormal discharge from occurring near gas inlet 433.

[0042] The abnormal discharge referred to here refers to the following phenomenon, for example. When Ar gas, which facilitates discharge, is added to the processing gas, discharge occurs between the first baffle plate 460a and the lid portion 454a due to the effect of the electric field generated by the resonance coil 432. In particular, discharge is likely to occur near the gas introduction hole 433 because this is an area where the processing gas is likely to remain. The cause of this discharge is presumably due to the addition of Ar gas. Since Ar gas has a property of facilitating discharge, it is considered that the process gas discharges even if the electric field generated by the resonant coil 432 is weak at a distance.

[0043] If discharge occurs, the following problems may occur: One is that plasma generated near the gas inlet 433 enters the gas supply pipe 455, etching the gas supply pipe 455. The etching may generate particles. In particular, if the gas supply pipe 455 is made of metal, the processing chamber 445 may be contaminated with metal, which may adversely affect the substrate processing. Secondly, there is a risk that plasma generated between first baffle plate 460a and lid portion 454a may come into contact with O-ring 431a, accelerating the deterioration of O-ring 431a.

[0044] As a result of extensive research, the inventors discovered that the discharge can be suppressed by increasing the flow rate of the processing gas. Specifically, the distance between first baffle plate 460a and lid portion 454a is narrowed. By adopting such a structure, the pressure between first baffle plate 460a and lid portion 454a can be increased, and as a result, the gas flow rate can be increased.

[0045] Next, a description will be given of the positional relationship between the second baffle plate 460b and the resonance coil 432. The second baffle plate 460b is configured so that the surface of the second baffle plate 460b that faces the susceptor table 411 is located at a height above the upper end (line AA) of the resonance coil 432. In other words, the second baffle plate 460b is configured to be located between the upper end of the resonance coil 432 and the first baffle plate 460a. With this configuration, the gas flows near the resonance coil 432, enabling efficient plasma generation. Furthermore, it is possible to prevent the diffusion and deactivation of the plasma and supply as many active reactive species as possible to the downstream wafer. By placing the second baffle plate 460b close to the upper end of the resonance coil 432, it is possible to reduce the volume of the plasma generation region and increase the plasma density per unit volume. Therefore, it is possible to transport as many active reactive species as possible downstream. The baffle structure is constructed as described above.

[0046] Here, the gas flow velocity will be explained with reference to FIG. FIG. 6 is a flow velocity distribution diagram. 6(a) shows an example using a baffle plate 460 according to a comparative example, where a single baffle plate is used, while (b) shows an example using the baffle plate 460 according to the present embodiment, where two baffle plates 460a and 460b are used. In the comparative example in which only one baffle plate 460 is used, it is found that the flow rate is low near gas inlet 433 and high between baffle plate 460 and lid 454a. It is also found that gas is accumulating in a spiral shape. From this, it is presumed that abnormal gas discharge occurs between baffle plate 460 and lid 454a. On the other hand, in the example in which two baffle plates 460 according to this embodiment are used, gas does not remain between the first baffle plate 460a and the lid portion 454a, so it is understood that discharge can be suppressed.

[0047] FIG. 7 shows the relationship between RF power, baffle plate 460, and discharge. The vertical axis represents the RF power applied to resonance coil 432. The normal discharge limit power was measured in each of the following states: without baffle plate 460, with one baffle plate 460, and with two baffle plates 460. The normal discharge limit power is the power at which no abnormal discharge occurs. The process conditions at this time are as follows: Atmosphere: PR-GAS (CH4: 10%, Ar: 90%) Flow rate: 0.2~3.0slm Pressure: 50~250mTorr

[0048] As can be seen from this figure, without the baffle plate 460, normal discharge is possible up to 1000 W. Furthermore, with one baffle plate 460, normal discharge is possible up to 3000 W. Furthermore, with two baffle plates 460, normal discharge is possible up to 4900 W.

[0049] In the case of an ICP plasma generator, the higher the RF power, the more efficiently the plasma state can be created, so it is desirable to have a high RF power within the range where no abnormal discharge occurs. Therefore, a state with two baffle plates is more desirable than a state with no baffle plate or a state with only one baffle plate.

[0050] The resonant coil 432 has a winding diameter, a winding pitch, and a number of turns set so as to resonate in a constant wavelength mode in order to form a standing wave of a predetermined wavelength. That is, the electrical length of the resonant coil 432 is set to a length equivalent to an integer multiple (1x, 2x, ...) of one wavelength or a half or quarter wavelength of the predetermined frequency of the power supplied from the high frequency power supply 444. For example, the length of one wavelength is approximately 22 meters for 13.56 MHz, approximately 11 meters for 27.12 MHz, and approximately 5.5 meters for 54.24 MHz. Resonant coil 432 is made of an insulating material and has a flat plate shape, and is supported by a plurality of supports that are vertically provided on the upper end surface of base plate 448 .

[0051] Both ends of the resonant coil 432 are electrically grounded, and at least one end of the resonant coil 432 is grounded via a movable tap 462 in order to finely adjust the electrical length of the resonant coil when the apparatus is initially installed or when the processing conditions are changed. Reference numeral 464 in Fig. 3 indicates the other fixed ground. Furthermore, a power supply section is formed by a movable tap 466 between the grounded ends of the resonant coil 432 in order to finely adjust the impedance of the resonant coil 432 when the apparatus is initially installed or when the processing conditions are changed.

[0052] That is, the resonant coil 432 has electrically grounded ground parts at both ends, and has a power supply part between each ground part, which is supplied with power from the high frequency power supply 444, and at least one of the ground parts is a variable ground part whose position is adjustable, and the power supply part is a variable power supply part whose position is adjustable. When the resonant coil 432 has a variable ground part and a variable power supply part, it is possible to adjust the resonant frequency and load impedance of the plasma generation chamber 430 more easily, as described later.

[0053] Outer shield 452 is provided to prevent electromagnetic waves from leaking out of resonance coil 432 and to form a capacitance component required to configure a resonance circuit between resonance coil 432 and outer shield 452. Outer shield 452 is generally formed into a cylindrical shape using a conductive material such as an aluminum alloy, copper, or a copper alloy. Outer shield 452 is disposed at a distance of, for example, about 5 to 150 mm from the outer periphery of resonance coil 432.

[0054] An RF sensor 468 is installed on the output side of the high frequency power supply 444 to monitor the traveling wave, the reflected wave, etc. The reflected wave power monitored by the RF sensor 468 is input to the frequency matching device 446. The frequency matching device 446 controls the frequency so that the reflected wave is minimized.

[0055] 1, and does not simply control only the high-frequency power supply 444, but also controls the entire ashing device 10. A display 472 serving as a display unit is connected to the controller 470. The display 472 displays data detected by various detection units provided in the ashing device 10, such as the monitoring results of the reflected waves by the RF sensor 468.

[0056] For example, when the processing conditions are changed during the ashing process or during plasma processing during plasma generation before the ashing process (such as by increasing the type of gas), the gas flow rate, gas mixture ratio, and pressure may change, which may cause a change in the load impedance of the high frequency power supply 444. Even in such a case, since the ashing apparatus 10 has the frequency matching device 446, it is possible to match the transmission frequency of the high frequency power supply 444 by immediately following the changes in the gas flow rate, gas mixture ratio, and pressure.

[0057] Specifically, the following operations are performed. When plasma is generated, it is converged to the resonant frequency of the resonant coil 432. At this time, the RF sensor 468 monitors the reflected wave from the resonant coil 432 and transmits the level of the monitored reflected wave to the frequency matching device 446. The frequency matching device 446 adjusts the transmission frequency of the high frequency power supply 444 so that the reflected wave power is minimized.

[0058] Next, a semiconductor manufacturing method that employs the substrate processing method (photoresist removal method) of the present invention as one step will be described with reference to Fig. 8. Fig. 8 illustrates a process for manufacturing a semiconductor device using an ashing apparatus 10 and the like by employing the substrate processing method of the present invention.

[0059] FIG. 8 shows a process of processing a substrate (wafer 600) using the ashing apparatus 10, which is a substrate processing method according to an embodiment of the present invention. In the substrate processing method according to the present invention, as shown in FIG. 8, the substrate is processed through a series of steps including at least a loading step S100 for loading the substrate into a processing chamber, a heating step S200 for heating the substrate, a processing step S300 for supplying a reactive gas and processing the substrate, and an unloading step S400 for unloading the substrate from the processing chamber.

[0060] In the loading step S100, the wafer 600 coated with resist is loaded into the processing chamber 445. In the heating step S200, the wafer 600 loaded into the processing chamber 445 in the loading step S100 is heated. In the processing step S300, a reactive gas containing at least a hydrogen component and an argon component is supplied into the processing chamber 445. For example, PR-GAS (a mixed gas of CH4 and argon) is supplied. Furthermore, the reactive gas supplied into the processing chamber is made into a plasma state to process the wafer 600. In the unloading step S400, the processed wafer 600 is unloaded from the processing chamber 445.

[0061] An example of substrate processing using the ashing apparatus 10 will now be described in more detail. The operation of each part of the ashing device 10 is controlled by a controller 470.

[0062] <Delivery process S100> In the loading step S100, the fingers 321 of the vacuum arm robot 320 transport the wafer 600 to the processing chamber 445. That is, the fingers 321 carrying the wafer 600 enter the processing chamber 445, and the fingers 321 place the wafer 600 on the lifter pins 413 that have been raised. The tips of the lifter pins 413 are maintained in a state floating above the susceptor table 411. The wafer 600 is transferred onto the lifter pins 413, that is, in a state floating above the susceptor table 411. At this time, the wafer 600 is held at, for example, room temperature.

[0063] [Heating process S200] In the heating step S200, the wafer 600 is held in a floating state above the susceptor table 411, and is heated by the heater 463 of the susceptor table 411. The wafer temperature is controlled by the distance between the susceptor table 411 and the wafer 600. In this heating step S200, the temperature of the wafer 600 is set to 200° C. or higher and 400° C. or lower.

[0064] [Processing step S300] In the process step S300 of supplying a reactive gas, a reactive gas (ashing gas) is supplied from a reaction vessel 431 to a gas inlet 433 into the plasma generation chamber 430. The supplied reactive gas contains at least a hydrogen component and an argon component.

[0065] After the processing chamber 445 is brought into a predetermined condition, the supplied reactive gas is made into a plasma state by the resonance coil 432. That is, after the reactive gas is supplied in the process of supplying the reactive gas, the high frequency power supply 444 supplies power to the resonance coil 432, and the induction magnetic field excited inside the resonance coil 432 accelerates free electrons, which are collided with gas molecules to excite the gas molecules and generate plasma. Then, the substrate is processed by the reactive gas made into the plasma state, and the resist is removed.

[0066] In this embodiment, a reaction gas containing at least a hydrogen component and an argon component is supplied as the reaction gas used in the process step S300. Here, Ar gas is used, but more specifically, a gas obtained by adding a dilution gas consisting of at least one gas selected from the group consisting of N2 gas and He gas to hydrogen can be used.

[0067] [Export process S400] In the unloading step S400, after the ashing process is completed, the lifter pins 413 rise. The fingers 321 of the vacuum arm robot 320 pick up the processed wafer 600 on the lifter pins 413 and transport it to the load lock chamber section 210 or the load lock chamber 220 via the transfer chamber section 310.

[0068] In this embodiment, the ashing process has been described as an example, but the present invention is not limited to this, and the present invention can be carried out in the form of any process using plasma, such as an etching process, a film modification process, or a film formation process.

[0069] In addition, in the present embodiment, an example in which two baffle plates are used has been described, but the present invention is not limited to this, and a plurality of baffle plates may be used between the upper end of the coil and the gas inlet.

[0070] As described above, this embodiment allows the gas to flow along the inner wall of the reaction vessel 431, and the gas can be supplied to an area with a strong electric field, thereby improving the plasma generation efficiency. In addition, a high-energy, long-life plasma is generated. Therefore, processing at a high ashing rate becomes possible, and as a result, the throughput of the entire apparatus can be increased.

[0071] The present invention is as defined in the claims and further includes the following supplementary items.

[0072] [Appendix 1] A substrate processing apparatus comprising: a cylindrical reaction vessel having a coil disposed around its outer periphery; a lid provided at an end of the reaction vessel; a gas inlet provided in the lid; a first plate provided between the gas inlet and an upper end of the coil; a second plate provided between the first plate and an upper end of the coil; a substrate processing chamber provided inside the reaction vessel in a direction different from that of the lid; and a gas exhaust section connected to the substrate processing chamber.

[0073] [Appendix 2] 2. The substrate processing apparatus according to claim 1, further comprising an O-ring on an outer periphery of a tip of the reaction vessel.

[0074] [Appendix 3] A method for manufacturing a semiconductor device using a substrate processing apparatus having a cylindrical reaction vessel with a coil provided on its outer periphery, a lid provided at an end of the reaction vessel, a gas inlet provided in the lid, a first plate provided between the gas inlet and an upper end of the coil, a second plate provided between the first plate and an upper end of the coil, a substrate processing chamber provided in a direction different from the lid within the reaction vessel, and a gas exhaust section connected to the substrate processing chamber, the method comprising the steps of: directing gas introduced from the gas inlet through the first plate and the second plate to the vicinity of the coil; turning the gas into a plasma state by the coil to process a substrate placed in the substrate processing chamber; and exhausting the gas by the gas exhaust section.

[0075] [Appendix 4] A baffle structure for use in a substrate processing apparatus having a cylindrical reaction vessel with a coil disposed around its outer periphery, a lid provided at an end of the reaction vessel, a gas inlet provided in the lid, a substrate processing chamber provided inside the reaction vessel in a different direction from the lid, and a gas exhaust section connected to the substrate processing chamber, wherein a first plate and a second plate are stacked and arranged between the gas inlet and the upper end of the coil.

[0076] [Appendix 5] A baffle structure for use in a substrate processing apparatus having a cylindrical reaction vessel with a coil disposed around its outer periphery, a lid provided at an end of the reaction vessel, a gas inlet provided in the lid, a substrate processing chamber provided inside the reaction vessel in a direction different from that of the lid, and a gas exhaust section connected to the substrate processing chamber, wherein the baffle structure is formed by stacking a first plate and a second plate with a space between them, and the height of the baffle structure is configured to be lower than the distance between the gas inlet and the upper end of the coil. [Explanation of symbols]

[0077] 10...Ashing device 100…EFEM 110, 120...FOUP 130…Atmospheric robot 200: Load lock chamber 210, 220...Buffer unit 211, 221... Boat 212, 222... Index Assembly 250, 260... Load lock chamber 300...Transfer chamber section 310...Transfer chamber 311, 312, 313, 314...Gate valves 320…Vacuum arm robot unit 321...Finger 325...θ axis 326…Y axis 400: Process chamber section 410, 420...Plasma treatment units 411, 421...Susceptor table 412, 422…Z axis 413, 423…Lifter pin 430, 440...Plasma generation chamber 431, 441...Reaction vessel 432, 442...Resonant coil 433, 443...Gas inlet 445…Processing room 444…High frequency power supply 446…Frequency matching device 448…Base plate 452…Outer shield 453…O-ring 454…Top plate 454a…Lid part 455...Gas supply pipe 458…Baffle ring 460…Baffle plate 462...Movable tap 463…Heater 464…Fixed ground 466…Movable tap 468…RF sensor 470,500…Controller 472...Display (display device) 480…Exhaust pipe 482…Gas supply unit 600…wafer

Claims

1. A reaction vessel; A coil provided on the outer periphery of the side wall of the reaction vessel; a gas inlet provided on an upper end surface of the reaction vessel inside the reaction vessel; a gas flow path forming portion provided within the reaction vessel between the gas inlet and an upper end of the coil, the gas flow path forming portion having an upper facing portion facing the upper end surface of the vessel and a lower facing portion facing a space surrounded by the coil within the reaction vessel; a first gap formed between an outer edge of the upper facing portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the upper facing portion; a second gap formed between an outer edge of the lower facing portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the lower facing portion; having The distance between the upper facing portion and the lower facing portion is greater than the width of the first gap and the width of the second gap. Substrate processing equipment.

2. A substrate processing apparatus as described in claim 1, wherein the upper opposing portion faces the upper end surface of the container at a distance of 5 mm or less.

3. A substrate processing apparatus as described in claim 1 or 2, wherein the distance between the upper opposing portion and the lower opposing portion is 30 mm or more.

4. 4. The substrate processing apparatus according to claim 1, wherein the width of the first gap and the width of the second gap are each 10 mm or less.

5. The substrate processing apparatus according to claim 1, wherein a width of the first gap is equal to a width of the second gap.

6. A substrate processing apparatus as described in any one of claims 1 to 5, wherein the upper opposing portion and the lower opposing portion have a shape without holes.

7. A reaction vessel; A coil provided on the outer periphery of the side wall of the reaction vessel; a gas inlet provided on an upper end surface of the reaction vessel inside the reaction vessel; a gas flow path forming portion provided within the reaction vessel between the gas inlet and an upper end of the coil, the gas flow path forming portion having an upper facing portion facing the upper end surface of the vessel and a lower facing portion facing a space surrounded by the coil within the reaction vessel; a first gap formed between an outer edge of the upper facing portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the upper facing portion; a second gap formed between an outer edge of the lower facing portion and an inner circumferential surface of the reaction vessel so as to surround the outer edge of the lower facing portion; having introducing a gas into the reaction vessel from the gas inlet of the substrate processing apparatus, the distance between the upper facing portion and the lower facing portion being greater than a width of the first gap and a width of the second gap; generating a plasma of the gas within the reaction vessel by supplying high frequency power to the coil; treating a substrate using the plasma generated in the reaction vessel; A method for manufacturing a semiconductor device having the above structure.

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