JP2009283794A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the within-wafer uniformity of the density of active species and ions supplied to the surface of a substrate and increase the amount of the active species and ions supplied to the surface of the substrate, when carrying out a substrate processing step by an ALD method. <P>SOLUTION: A substrate processing apparatus includes: a processing chamber for storing a plurality of substrates that are loaded in multilayers; a plasma generating chamber communicating with the processing chamber; a first process gas supply line for supplying a first process gas into the processing chamber; a second process gas supply line for supplying a second process gas into the processing chamber; a third process gas supply line for supplying a third process gas into the plasma generating chamber; a plasma generating device for generating electron source plasma in the plasma generating chamber supplied with the third process gas; an electron beam supply device for extracting electrons from the electron source plasma generated in the plasma generating chamber to irradiate the region between the substrates in the processing chamber; and an exhaust line for exhausting the processing chamber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for processing a substrate using plasma.

As a process of manufacturing a semiconductor device (device) such as a DRAM, a substrate processing process by an ALD (Atomic Layer Deposition) method that alternately supplies a plurality of types of processing gases to the surface of the substrate may be performed. is there. In such a substrate processing step, for example, a first processing gas is supplied into the processing chamber containing the substrate and reacted with the substrate surface, and then the processing chamber is evacuated, and a second processing gas is supplied into the processing chamber. The process is repeated after the reaction with the substrate surface and the process chamber is evacuated. In recent years, in order to reduce the amount of heat input to the substrate, active species (also referred to as radicals) or ions generated by plasma may be supplied to the substrate surface in the substrate processing step by the ALD method.
JP 2004-289166 A

  However, in the conventional substrate processing apparatus that implements the ALD method, since the distance between the plasma generation position and the substrate is large, the density of active species and ions supplied to the substrate surface is made uniform over the substrate surface. In some cases, the uniformity of substrate processing may be reduced. In addition, the active species or ions generated at the plasma generation position may be deactivated or electrically neutralized before reaching the substrate, and the active species or ions supplied to the substrate surface. In some cases, the substrate processing speed decreases.

  Therefore, the present invention improves the in-plane uniformity of the density of active species and ions supplied to the substrate surface when performing a substrate processing step by the ALD method, and the amount of active species and ions supplied to the substrate surface. An object of the present invention is to provide a substrate processing apparatus capable of increasing the thickness of the substrate.

According to one aspect of the invention,
A processing chamber for storing a plurality of substrates stacked in multiple stages;
A plasma generation chamber communicating with the processing chamber;
A first processing gas supply line for supplying a first processing gas into the processing chamber;
A second processing gas supply line for supplying a second processing gas into the processing chamber;
A third processing gas supply line for supplying a third processing gas into the plasma generation chamber;
A plasma generator for generating electron source plasma in the plasma generating chamber supplied with a third processing gas;
An electron beam supply device that extracts electrons from the electron source plasma generated in the plasma generation chamber and irradiates the region between the substrates in the processing chamber;
An exhaust line for exhausting the processing chamber,
After the first processing gas is supplied from the first processing gas supply line into the processing chamber and reacted with the substrate surface, the processing chamber is exhausted from the exhaust line, and the processing chamber is exhausted from the second processing gas supply line. A second processing gas is supplied into the chamber, a third processing gas is supplied into the plasma generation chamber from the third gas supply line, and an electron source plasma is generated by the plasma generator, and the electron beam supply device Thus, there is provided a substrate processing apparatus for generating a reaction contributing plasma by irradiating an area between the substrates in the processing chamber with electrons and processing the substrate surface with the reaction contributing plasma.

  According to the substrate processing apparatus of the present invention, when performing the substrate processing step by the ALD method, the in-plane uniformity of the density of active species and ions supplied to the substrate surface is improved, and the substrate is supplied to the substrate surface. The amount of active species and ions can be increased.

  First, for reference, the configuration of a processing furnace of a conventional substrate processing apparatus (batch type plasma processing apparatus) will be described with reference to FIGS.

  As shown in FIGS. 10 and 11, the conventional processing furnace includes a process tube 7 ′ as a reaction tube and a pair of protective tubes 8 ′ provided vertically along the inner wall surface of the process tube 7 ′. Have. Housed in the process tube 7 ′ is a boat 3 ′ as a substrate support for supporting wafers 6 ′ as substrates in a horizontal posture in multiple stages. The lower end of the protective tube 8 'passes through the side wall of the process tube 7' toward the outside of the process tube 7 '. In the pair of protective tubes 8 ', a pair of electrodes 9' connected to the high frequency power source 13 'is inserted from the lower end of the protective tube 8'. On the inner wall of the process tube 7 ′, a bowl-shaped partition wall 11 ′ that forms the plasma generation chamber 10 ′ is installed so as to airtightly surround the pair of protective tubes 8 ′. A plurality of air outlets 12 ′ are arranged in the partition wall 11 ′ so as to face the region between the wafers 6 accommodated in the process tube 7 ′.

  When the processing gas is supplied into the plasma generation chamber 10 ′ and the high frequency power is supplied to the pair of electric powers 9 ′, plasma is formed in the plasma generation chamber 10 ′, and the plasma generation chamber 10 ′. The processing gas supplied inside is activated to generate electrically neutral active species (radicals) and ions. Then, the generated active species and ions are blown out from the blowout opening 12 ′, supplied to the region between the wafers 6 accommodated in the process tube 7 ′, and the surface of the wafer 6 ′ is processed.

  However, in the above-described conventional substrate processing apparatus, the distance between the plasma generation chamber 10 '(plasma generation position) and the wafer 6' (substrate) is large. For this reason, it is difficult to make the density of active species and ions supplied to the surface of the wafer 6 ′ uniform within the surface of the wafer 6 ′, and the substrate processing uniformity may be reduced. In addition, active species and ions generated in the plasma generation chamber 10 ′ may be deactivated or electrically neutralized before reaching the substrate, and are supplied to the surface of the wafer 6 ′. In some cases, the density of active species and ions is reduced, and the substrate processing speed is reduced.

  Therefore, the inventors have improved the in-plane uniformity of the density of active species and ions supplied to the substrate surface and the active species and ions supplied to the substrate surface when performing the substrate processing process by the ALD method. The method of increasing the amount of scientists was intensively studied. As a result, the inventors have obtained knowledge that the problems described above can be solved by supplying an electron beam to the region between the substrates to generate plasma near the substrates. The present invention is based on such knowledge obtained by the inventors.

(1) Configuration of Substrate Processing Apparatus The configuration of a substrate processing apparatus according to one embodiment of the present invention will be described below with reference to FIGS. 9, 2, 2, and 7. FIG. FIG. 9 is an overall configuration diagram of the substrate processing apparatus according to the present embodiment. FIG. 2 is a longitudinal sectional view of a processing furnace provided in the substrate processing apparatus according to the present embodiment, and FIG. 1 is an XX sectional view of the processing furnace according to the present embodiment shown in FIG. FIG. 7 is a cross-sectional configuration diagram of a processing furnace showing an arrangement example of gas supply lines according to the present embodiment.

As shown in FIG. 9, the substrate processing apparatus according to this embodiment is mounted on a cassette stocker 1 for mounting a wafer cassette as a wafer (substrate) transfer container, a boat 3 as a substrate holder, and the cassette stocker 1. A wafer transfer means (transfer machine) 2 for transferring wafers between the wafer cassette and the boat 3, a boat elevating means (boat elevator) 4 for transferring the boat 3 into and out of the processing furnace 5, and a heating means. And a processing furnace 5 including a (heater).

(Process tube)
As shown in FIGS. 1 and 2, the processing furnace 5 of the substrate processing apparatus according to this embodiment has a process tube 7 as a reaction tube. The process tube 7 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with the upper end closed and the lower end opened. A process chamber 46 for processing a wafer 6 as a substrate is formed in the process tube 7. The boat 3 as a substrate support is loaded into the processing chamber 46 by the boat lifting / lowering means 4. The boat 3 is configured to support a plurality of wafers 6 in multiple stages in the vertical direction in a horizontal posture and with the centers aligned. When the boat 3 is carried into the processing chamber 46, the lower end portion of the process tube 7 is configured to be hermetically sealed. The boat 3 is supported from below by the rotation shaft of the rotation mechanism 36. By operating the rotation mechanism 36, the wafer 6 can be rotated in the processing chamber 46 during substrate processing. The rotation shaft of the rotation mechanism 36 is supported by a bearing while maintaining the airtightness in the processing chamber 46. A heater 16 for heating the surface of the wafer 6 in the processing chamber 46 is provided so as to surround the outer periphery of the process tube 7.

(Plasma generation chamber)
A partition wall 11 extending in the vertical direction is provided on the inner wall of the process tube 7. A plasma generation chamber 17 communicating with the inside of the processing chamber 46 is formed by the inner wall of the process tube 7 and the partition wall 11. The partition wall 11 is concentric with the process tube 7 and has a central wall 11a having a circular arc cross section formed along the outer periphery of each wafer 6 supported by the boat 3, an end of the central wall 11a, and the process tube 7 And a connecting wall 11b for connecting the inner wall.

  The central wall 11a of the partition wall 11 is provided with a plurality of air outlets 12 for blowing out electrons (electron beam 24). The air outlet 12 is configured to eject an electron beam (electron beam) between the wafers 6 that are supported in multiple stages in the vertical direction in the process tube 7. The air outlets 12 are arranged at equal intervals in the vertical direction so as to face the center direction of the wafers 6 supported by the boat 3 and to correspond to the height positions of the regions between the adjacent wafers 6. . The air outlet 12 is not limited to the direction of the center of the wafer 6, and may be configured to face in a direction slightly deviated from the center of the wafer 6. The processing chamber 46 and the plasma generation chamber 17 are communicated with each other through the air outlet 12. The partition wall 11 divides the processing chamber 46 and the plasma generation chamber 17 in an airtight manner except for the air outlet 12.

(Gas supply line)
The processing furnace 5 according to the present embodiment includes a first processing gas supply line that supplies, for example, SiH ₂ Cl ₂ gas (hereinafter also referred to as source gas A) as a first processing gas into the processing chamber 46, and a processing chamber. A second processing gas supply line for supplying, for example, NH ₃ gas (hereinafter also referred to as reaction gas B) as a second processing gas into the 46, and a He gas as a third processing gas into the plasma generation chamber 17 (see FIG. And a third processing gas supply line for supplying an electron source gas C).

A downstream end portion of the first processing gas supply line is connected to a first supply nozzle 33 shown in FIG. 7 via a gas introduction port 37 a that penetrates the side wall of the process tube 7. Further, the downstream end portion of the second processing gas supply line is connected to the second supply nozzle 34 shown in FIG. 7 via a gas introduction port 37 b penetrating the side wall of the process tube 7. Further, the downstream end of the third process gas supply line is connected to a third supply nozzle 35 shown in FIG. 7 via a gas introduction port (not shown) that penetrates the side wall of the process tube 7. Therefore, the first supply nozzle 33 is configured to directly supply the source gas A (SiH ₂ Cl ₂ gas) supplied from the first process gas supply line not into the plasma generation chamber 17 but into the process chamber 5. ing. The second supply nozzle 34 is configured to directly supply the source gas B (NH ₃ gas) supplied from the second processing gas supply line not into the plasma generation chamber 17 but into the processing chamber 5. The third supply nozzle 35 is configured to directly supply the electron source gas C (He gas) supplied from the third processing gas supply line not into the processing chamber 5 but into the plasma generation chamber 17.

  A plurality of gas supplies are supplied to the first supply nozzle 33 and the second supply nozzle 34 so as to face the center direction of the wafer 6 and to correspond to the height position of the region between the adjacent wafers 6. Each mouth is preferably provided. Further, the third supply nozzle 35 faces the region between the inner wall of the process tube 7 and the grid electrode 19 described later, and corresponds to the height position of the region between the adjacent wafers 6. It is preferable that a plurality of gas supply ports are provided.

Further, it is preferable to further include a purge gas supply line (not shown) for supplying purge gas into the plasma generation chamber 17. In such a case, the downstream end of the purge gas supply line is connected to a purge gas supply nozzle (not shown) through a gas introduction port (not shown) that penetrates the side wall of the process tube 7. The purge gas supply nozzle is preferably configured to directly supply the purge gas supplied from the purge gas supply line not into the processing chamber 5 but into the plasma generation chamber 17. The purge gas can be other inert gas such as He gas, Ar gas, or N ₂ gas. Further, the purge gas supply line is not limited to this embodiment, and may be provided integrally with the third process gas supply line. That is, the third process gas supply line described above may also be configured to function as a purge gas supply line that supplies a purge gas into the plasma generation chamber 17.

(Plasma generator)
An inductively coupled plasma (ICP) source having a pair of electrodes 22 made of a conductive material such as metal or carbon is provided at a position corresponding to the plasma generation chamber 17 on the outer peripheral side of the process tube 7. Has been placed. A metal shield 23 is disposed between the electrode 22 and the process tube 7. A high frequency power supply 13 is connected to both ends of the pair of electrodes 22. The electrode 22, the shield 23, and the high-frequency power source 13 constitute a plasma generator that generates electron source plasma in the plasma generation chamber 17 to which the electron source gas C (He gas) as the third processing gas is supplied. Yes.

(Electron source supply device)
In the plasma generation chamber 17, a flat grid electrode (bias electrode) 19 extending vertically and a flat anode electrode (acceleration electrode) 20 extending vertically are provided. The grid electrode 19 and the anode electrode 20 are provided so that their main surfaces face each other in parallel. The grid electrode 19 is provided so as to face the inner wall of the process tube 7, and the anode electrode 20 is provided so as to face the central wall 11a of the partition wall. Further, between the grid electrode 19 and the anode electrode 20, a flat plate-like intermediate electrode (control electrode) 29 that similarly extends vertically is provided.

The grid electrode 19 is connected to the cathode side of the DC power supply 21, and the anode electrode 20 is connected to the anode side of the DC power supply 21. Further, the anode side of the DC power supply 31 is connected to the intermediate electrode 29. The anode side of the DC power source 21 and the cathode side of the DC power source 31 are grounded. That is, the grid electrode 19 has a negative potential, the intermediate electrode 29 has a positive potential, and the anode electrode 20 has a zero potential.

  As shown in FIG. 3, the grid electrode 19, the intermediate electrode 29, and the anode electrode 20 have electron passage holes 19 a, 29 a, and 20 a that are concentric with each other at positions corresponding to the air outlet 12. A plurality are provided.

  The grid electrode 19, the anode electrode 20, the intermediate electrode 29, the DC power source 21, and the DC power source 31 extract electrons from the electron source plasma generated in the plasma generation chamber 17 while focusing them, thereby generating an electron beam 24. An electron source supply device for irradiating the region between the wafers 6 in the processing chamber 46 is configured.

(Exhaust line)
An exhaust port 32, which is an opening for exhausting the atmosphere in the processing chamber 46, is provided on the side wall of the process tube 7 opposite to the side where the plasma generation chamber 17 is provided. An exhaust line (not shown) provided with a vacuum pump 38 is connected to the exhaust port 32.

(2) Operation of the Substrate Processing Apparatus Next, in addition to the above-described figures, the operation of the substrate processing apparatus according to the present embodiment for forming a silicon nitride (SiN) film by the ALD method will be described with reference to FIGS. Description will be made with reference to FIGS. FIG. 3 is a schematic diagram for explaining the generation mechanism of the reaction-contributing plasma according to the present embodiment. 4 to 6 are enlarged views of main parts of FIG. FIG. 8 is a schematic diagram illustrating a gas supply sequence according to the present embodiment. The control of each component in the following operation is performed by the controller 50 as a control means.

  First, a wafer cassette containing a wafer 6 to be processed is stored in the cassette stocker 1. Then, the wafer transfer means 2 transfers the wafer 6 to be processed from the wafer cassette mounted on the cassette stocker 1 to the boat 3. Then, the boat 3 supporting the wafer 6 to be processed is carried into the processing furnace 5 by the boat lifting / lowering means 4 and the inside of the processing chamber 46 is hermetically sealed (loading step).

  Thereafter, the vacuum pump 38 is operated to depressurize the inside of the processing chamber 46 to a predetermined pressure. Then, the surface of the wafer 6 in the processing chamber 46 is heated by the heater 16 while the rotation mechanism 36 is operated (rotated) to rotate the wafer 6 (decompression and temperature raising step).

(Process 1)
Then, as shown in FIG. 8, a source gas A (SiH ₂ Cl ₂ gas) as a first process gas is introduced into a process chamber 46 containing the wafer 6 from a first process gas supply line (first supply nozzle 33). ) To react with the surface of the wafer 6 (step 1). As a result, gas molecules of the source gas A (SiH ₂ Cl ₂ gas) are adsorbed on the surface of the wafer 6.

  At this time, it is preferable to supply the purge gas into the plasma generation chamber 17 from the purge gas supply line (purge gas supply nozzle). Thereby, it is possible to suppress the source gas A supplied into the processing chamber 46 from the first processing gas supply line from entering the plasma generation chamber 17. The purge gas is directly supplied not into the processing chamber 5 but into the plasma generation chamber 17, thereby generating a purge gas flow from the plasma generation chamber 17 toward the processing chamber 46 through the blowout port 12, or The pressure in the plasma generation chamber 17 is increased, and the intrusion of the raw material gas A into the plasma generation chamber 17 can be suppressed.

(Process 2)
After a predetermined time has elapsed, the supply of the source gas A from the first processing gas supply line is stopped, the inside of the processing chamber 46 is exhausted by the above-described exhaust line, and the inside of the processing chamber 46 is reduced to a predetermined pressure (step) 2). At this time, if a purge gas such as He gas is supplied into the plasma generating chamber 17 and an inert gas such as N ₂ gas is supplied into the processing chamber 46, the inside of the plasma generating chamber 17 and the processing chamber 46 may be provided. The speed of exhausting the residual atmosphere is further increased.

(Process 3)
Then, as shown in FIG. 8, the reaction gas B (NH ₃ gas) as the second process gas is supplied into the process chamber 46 from the second process gas supply line (second supply nozzle 34), and the third process gas is supplied. An electron source gas C (He gas) as (third process gas) is supplied into the plasma generation chamber 17 from the gas supply line (third supply nozzle 35). Then, as shown below, an electron source plasma is generated by a plasma generation device, and an electron beam supply device irradiates electrons to a region between the wafers 6 in the processing chamber 46 to emit electron beam excited plasma (EBEP: Electron-Beam-). Reaction-contributing plasma which is an Excited-Plasma) is generated, and the surface of the wafer 6 is processed by the reaction-contributing plasma (step 3).

  Below, the generation mechanism of reaction contribution plasma is demonstrated concretely.

In a state where the electron source gas C (He gas) is supplied into the plasma generation chamber 17, the high frequency power is applied to the electrode 22 by the high frequency power source 13, thereby generating the electron source plasma in the plasma generation chamber 17. . As shown in FIG. 3, in the electron source plasma generated in the plasma generation chamber 17, positive ions (represented as C ^{+ in the} figure) 25 and electrons (in the figure) of the electron source gas C (He gas). 26), which is neutral as a whole.

Therefore, the DC power supply 21 and the DC power supply 31 are operated to generate predetermined electric fields between the grid electrode 19, the intermediate electrode 29, and the anode electrode 20, respectively. As a result, the electrons 26 in the electron source plasma are subjected to trajectory correction by the grid electrode 19 in which the electron passage holes 19a are formed in multiple stages in the vertical direction, and are converged. It is extracted by being accelerated toward the anode electrode 20 in which the electron passage hole 20a is formed. The accelerated (extracted) electrons 26 become electron beams (electron beams) 24 and are ejected from the blowout ports 12 formed in multiple stages in the partition wall 11, and enter the region between the wafers 6 supported by the boat 3. The gas molecules (represented as B in the figure) 28 of the supplied reactive gas B (NH ₃ gas) are irradiated. As a result, reaction contributing plasma (EBEP) is generated in the region between the wafers 6 supported by the boat 3, and the gas molecules 28 of the reaction gas B (NH ₃ gas) are excited to generate active species, 27 (denoted as B ^{+ in the} figure).

Then, the gas molecules of the source gas A adsorbed on the surface of the wafer 6 react with the active species, or the gas molecules react with the ions (B ⁺ ) 27 to cause silicon nitride (SiN) on the surface of the wafer 6. ) A film is formed.

As shown in FIG. 3, the ions (B ⁺ ) 27 generated in the region between the wafers 6 are not electrically neutral, and therefore flow in the direction 30 opposite to the electron beam 24, and the partition 11 Attempts to flow into the plasma generation chamber 17 through the air outlets 12 formed in multiple stages. However, by applying a positive voltage from the DC power source 31 to the intermediate electrode 29 installed between the grid electrode 19 and the anode electrode 20, the ions (B ⁺ ) 27 undergo trajectory correction and become zero potential. It will be absorbed by the installed anode electrode 20. Thereby, it can suppress that ion (B ^<+> ) 27 flows into the plasma generation chamber 17 and collides with the grid electrode 19, can suppress that the grid electrode 19 is sputtered | sputtered, and is in the plasma generation chamber 17. FIG. Electron source plasma can be generated stably.

  However, applying a voltage to the intermediate electrode 29 as described above may affect the trajectory and acceleration of electrons in the plasma generation chamber 17. Therefore, it is necessary to limit the voltage value applied to the intermediate electrode 29 within a predetermined range. Such a range can be obtained experimentally.

(Process 4)
Thereafter, the supply of the source gas A from the second process gas supply line is stopped, and the supply of the electron source gas C (He gas) from the third process gas supply line is stopped. Then, the inside of the processing chamber 46 is exhausted by the above-described exhaust line, and the inside of the processing chamber 46 is reduced to a predetermined pressure (step 4). At this time, if a purge gas such as He gas is supplied into the plasma generating chamber 17 and an inert gas such as N ₂ gas is supplied into the processing chamber 46, the inside of the plasma generating chamber 17 and the processing chamber 46 may be provided. The speed of exhausting is further increased.

  Then, the above-described steps 1 to 4 are set as one cycle, and this cycle is repeated a predetermined number of times to form a SiN film having a predetermined thickness on the surface of the wafer 6, thereby completing the substrate processing step according to the present embodiment. Thereafter, the boat 3 supporting the processed wafer 6 is unloaded from the processing chamber 46, and the processed wafer 6 is transferred from the boat 3 into the cassette stocker 1 by a procedure reverse to the above-described procedure. Transport to the next processing step.

(3) Effects According to the Present Embodiment According to the present embodiment, one or more effects described below are exhibited.

  According to the present embodiment, electrons are not irradiated from the front surface (directly above) of the wafer 6 supported in a horizontal posture, but an electron beam is irradiated from a direction along the surface of the wafer 6, for example, parallel to the surface. . If the electron beam 24 is radiated from the front (directly above) the wafer 6, it is necessary to widen the beam diameter of the electron beam 24, which requires components such as lenses and electrodes, and the structure of the substrate processing apparatus is complicated. In addition, it becomes difficult to make the electron density in the electron beam 24 uniform. In contrast, in the present embodiment, since the electron beam 24 is irradiated in parallel with the surface of the wafer 6, there are few such problems, and reaction contributing plasma (EBEP) is generated in a wide range near the surface of the wafer 6. Therefore, the in-plane uniformity of the density of the active species and ions 27 supplied to the surface of the wafer 6 can be improved, and the uniformity of substrate processing in the surface of the wafer 6 can be improved.

  According to the present embodiment, since the wafer 6 is rotated during the substrate processing, the reaction contributing plasma (EBEP) can be generated uniformly in the plane of the wafer 6, and the active species supplied to the surface of the wafer 6. In addition, it is possible to improve the in-plane uniformity of the density of ions 27 and improve the uniformity of substrate processing in the wafer 6 plane.

  According to this embodiment, reaction contributing plasma (EBEP) is generated in a region between the wafers 6 supported by the boat 3, and active species and ions 27 are generated in the immediate vicinity of the wafers 6. That is, even when the lifetime of the active species and ions 27 is short, the active species and ions 27 are generated at a distance from the wafer 6 and the amount of active species and ions supplied to the surface of the wafer 6 is short. As a result, the substrate processing efficiency can be improved.

  According to this embodiment, since the wafer 6 is not directly exposed to high energy plasma generated by capacitively coupled plasma (CCP) or the like, it is possible to suppress the wafer 6 itself from being damaged by the plasma.

  According to the present embodiment, in the plasma generation chamber 17, it is only necessary to generate plasma (electron source plasma) only for taking out the electrons 26, so it is not necessary to apply a high output high frequency, and the process tube 7 is configured. It is possible to reduce the amount of sputtering such as quartz walls.

  According to the present embodiment, an ICP source is used as the plasma generator, and the ICP source is provided outside the process tube 7. Therefore, the ICP source cannot be a contamination source in the processing chamber 46 as compared with the case where a filament (ultra-high temperature metal) is used, and is very clean.

According to this embodiment, He (atomic weight: 4.0006) gas having a small atomic weight is used as the electron source gas C. Therefore, the amount of sputtering of the grid electrode 19 can be suppressed, and plasma can be stably generated in the plasma generation chamber 17. The mechanism by which the grid electrode 19 is sputtered is shown in FIG. Since the grid electrode 19 is set to a negative potential, the positive ions (C ⁺ ) 25 generated in the plasma generation chamber 17 in the step 3 are accelerated toward the grid electrode 19 and collide with the surface of the grid electrode 19. 19 The surface may be sputtered. The amount of sputtering is related to the kinetic energy of positive ions (C ⁺ ) 25. If Ar gas is used as the electron source gas C, since the atomic weight of Ar is relatively large at 39.95, the sputtering amount of the grid electrode 19 increases. According to the present embodiment, since He has a small atomic weight of 4.0006, such a problem can be avoided.

According to this embodiment, He gas which is a non-reactive rare gas is used as the electron source gas C. Therefore, it is possible to suppress the grid electrode 19 and the like from being chemically etched or surface-modified. On the other hand, if a reactive gas such as H ₂ gas is used as the electron source gas C, the grid electrode 19 or the like may be chemically etched or surface modified.

According to the present embodiment, He gas, which is a non-reactive rare gas, is used as the electron source gas C, not a processing gas that contributes to film formation. For this reason, it is possible to suppress the formation of a film in the plasma generation chamber 17, and it is possible to stably generate plasma in the plasma generation chamber 17. That is, when the source gas A (SiH ₂ Cl ₂ gas) as the first processing gas is supplied into the processing chamber 46 in the step 1, the gas of the source gas A is put into the plasma generation chamber 17 as shown in FIG. A molecule (denoted as A in the figure) may enter. In this state, for example, NH ₃ gas used for the reaction gas B is used as the electron source gas C, and when this is supplied into the plasma generation chamber 17, the source gas A that has entered the plasma generation chamber 17 as shown in FIG. And the positive ions (denoted as C ^{+ in the} figure) of NH ₃ gas molecules as the electron source gas C react with each other, and a reaction product E such as SiN is deposited in the plasma generation chamber 17. Film formation may occur. In such a case, the state of the electron source plasma may change, thereby reducing the uniformity and reproducibility of the reaction-contributing plasma (EBEP). According to this embodiment, since the He gas, which is a non-reactive rare gas, is used as the electron source gas C instead of the processing gas that contributes to the film formation, the reaction product E does not accumulate, and this problem is solved. Can be avoided.

  According to the present embodiment, as the electron source gas C, He gas, which is a non-reactive rare gas, is always used regardless of the type of film to be deposited. Assuming that a processing gas that contributes to film formation is used as the gas type of the electron source gas C, the gas type of the electron source gas C is changed every time the film type to be formed is changed. In other words, the state of the reaction-contributing plasma (EBEP) changes greatly, and it becomes necessary to adjust the substrate processing conditions each time. According to the present embodiment, even if the type of film to be formed is changed, since He gas is always used as the electron source gas C, the states of the electron source plasma and the reaction-contributing plasma (EBEP) are unlikely to change, and the substrate processing It is possible to stabilize the conditions.

According to the present embodiment, in step 1, the purge gas can be supplied into the plasma generation chamber 17 from the purge gas supply line (purge gas supply nozzle). As a result, the first
The raw material gas A supplied into the processing chamber 46 from the processing gas supply line is prevented from entering the plasma generation chamber 17, and plasma can be stably generated in the plasma generation chamber 17. For example, when the purge gas is directly supplied into the plasma generation chamber 17 instead of into the processing chamber 5, a flow of the purge gas from the plasma generation chamber 17 to the processing chamber 46 is generated via the outlet 12, or The pressure in the plasma generation chamber 17 is increased, and the intrusion of the raw material gas A into the plasma generation chamber 17 can be suppressed.

<Other Embodiments of the Present Invention>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications.

Although the case where the SiN film is formed has been described in the above-described embodiment, the present invention is not limited to the above-described embodiment. For example, the present invention can be applied to the formation of a SiO film, a nano halide, and a metal film, and can be applied without limiting the film type as long as it is a substrate process using plasma. The present invention is also applicable to the case where the natural oxide film on the wafer 6 is removed by H ₂ active species using plasma.

  In the above-described embodiment, an ICP source by applying a high frequency is used as an example of the plasma generating device in the plasma generating chamber 17, but the present invention is not limited to this. For example, a plasma generator using another method may be employed as long as the plasma generation method suppresses the sputtering effect as much as possible, such as electron cyclotron resonance plasma and surface wave plasma.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

The first aspect is
A processing chamber for storing a plurality of substrates stacked in multiple stages;
A plasma generation chamber communicating with the processing chamber;
A first processing gas supply line for supplying a first processing gas into the processing chamber;
A second processing gas supply line for supplying a second processing gas into the processing chamber;
A third processing gas supply line for supplying a third processing gas into the plasma generation chamber;
A plasma generator for generating electron source plasma in the plasma generating chamber supplied with a third processing gas;
An electron beam supply device that extracts electrons from the electron source plasma generated in the plasma generation chamber and irradiates the region between the substrates in the processing chamber;
An exhaust line for exhausting the processing chamber,
After the first processing gas is supplied from the first processing gas supply line into the processing chamber and reacted with the substrate surface, the processing chamber is exhausted from the exhaust line, and the processing chamber is exhausted from the second processing gas supply line. A second processing gas is supplied into the chamber, a third processing gas is supplied into the plasma generation chamber from the third gas supply line, and an electron source plasma is generated by the plasma generator, and the electron beam supply device Thus, there is provided a substrate processing apparatus for generating a reaction contributing plasma by irradiating an area between the substrates in the processing chamber with electrons and processing the substrate surface with the reaction contributing plasma.

  Preferably, the second processing gas is helium gas.

Preferably, a first supply nozzle that supplies the first processing gas supplied from the first processing gas supply line into the processing chamber, and the second processing gas supplied from the second processing gas supply line. And a third supply nozzle for supplying the third processing gas supplied from the third processing gas supply line into the plasma generation chamber.

  Preferably, a purge gas supply line for supplying a purge gas into the plasma generation chamber is provided. More preferably, a purge gas nozzle for supplying the purge gas supplied from the purge gas supply line into the plasma generation chamber is provided.

Preferably, a step of supplying a first processing gas from the first processing gas supply line into the processing chamber to react with the substrate surface;
Exhausting the processing chamber from the exhaust line;
A second processing gas is supplied into the processing chamber from the second processing gas supply line, a third processing gas is supplied into the plasma generation chamber from the third gas supply line, and an electron source is supplied from the plasma generator. Generating plasma, irradiating electrons between regions of the substrate in the processing chamber by the electron beam supply device to generate reaction contributing plasma, and processing the substrate surface with the reaction contributing plasma;
Exhausting the processing chamber from the exhaust line;
Is repeated as one cycle.

It is XX sectional drawing of the processing furnace concerning one Embodiment of this invention shown in FIG. It is a longitudinal cross-sectional view of the processing furnace with which the substrate processing apparatus concerning one Embodiment of this invention is provided. It is the schematic explaining the generation | occurrence | production mechanism of the reaction contribution plasma concerning one Embodiment of this invention. It is a principal part enlarged view of FIG. It is a principal part enlarged view of FIG. It is a principal part enlarged view of FIG. It is a section lineblock diagram of a processing furnace which shows an example of arrangement of a gas supply line concerning one embodiment of the present invention. It is the schematic which shows the gas supply sequence concerning one Embodiment of this invention. 1 is an overall configuration diagram of a substrate processing apparatus according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the processing furnace of the conventional substrate processing apparatus. It is XX sectional drawing of the conventional processing furnace shown in FIG.

Explanation of symbols

2 Wafer transfer means 3 Boat (substrate support)
5 Processing furnace 6 Wafer (substrate)
7 Process tube 17 Plasma generating chamber 19 Grid electrode 20 Anode electrode 24 Electron beam 32 Exhaust port 33 First supply nozzle 34 Second supply nozzle 35 Third supply nozzle 46 Processing chamber 50 Controller

Claims (2)

A processing chamber for storing a plurality of substrates stacked in multiple stages;
A plasma generation chamber communicating with the processing chamber;
A first processing gas supply line for supplying a first processing gas into the processing chamber;
A second processing gas supply line for supplying a second processing gas into the processing chamber;
A third processing gas supply line for supplying a third processing gas into the plasma generation chamber;
A plasma generator for generating electron source plasma in the plasma generating chamber supplied with a third processing gas;
An electron beam supply device that extracts electrons from the electron source plasma generated in the plasma generation chamber and irradiates the region between the substrates in the processing chamber;
An exhaust line for exhausting the processing chamber,
After the first processing gas is supplied from the first processing gas supply line into the processing chamber and reacted with the substrate surface, the processing chamber is exhausted from the exhaust line,
A second processing gas is supplied into the processing chamber from the second processing gas supply line, a third processing gas is supplied into the plasma generation chamber from the third gas supply line, and an electron source is supplied from the plasma generator. A substrate processing apparatus characterized by generating plasma, irradiating electrons between regions of the substrate in the processing chamber with the electron beam supply device to generate reaction contributing plasma, and processing the substrate surface with the reaction contributing plasma. . The substrate processing apparatus according to claim 1, wherein the second processing gas is helium gas.

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