JP2008050662A - Substrate treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treatment device where the damage of a substrate caused by plasma is reduced, and to provide a method for fabricating a semiconductor. <P>SOLUTION: The substrate treatment device comprises: a treatment chamber for treating a substrate; a gaseous starting material feed port for feeding a gaseous starting material into the treatment chamber; a reaction gas feed port for feeding reaction gas into the treatment chamber; and a plasma generation section composed of at least one or more pairs of confronted comb type electrodes, and making reaction gas into plasma by applying high frequency voltage to the comb type electrodes. The plasma generation section is arranged between the substrate and the reaction gas feed port, and each comb type electrode composing the plasma generation section is covered with an insulation tube whose tip is sealed so as to be almost spherical shape. In the insulation tube, the connection side with a transformer is supported in a cantilever via an O ring, and the periphery of the supporting section in the insulation tube is purged with inert gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for forming a thin film on a substrate using plasma.

  As a semiconductor device having a thin film such as a conductive metal film on a substrate, there is a DRAM capacitor, for example. As the electrode shape of the capacitor, a cylinder type with a high aspect ratio is mainly used. Therefore, all films including the lower electrode film, the upper electrode film, and the barrier metal film need to be excellent in step coverage.

  Under such circumstances, a CVD (Chemical Vapor Deposition) method having excellent step coverage has been used as a method for forming a thin film on a substrate, instead of the conventional sputtering method. In particular, a reaction between an organometallic liquid raw material and an oxygen-containing gas, a hydrogen-containing gas, or a nitrogen-containing gas is used.

  In order to improve the step coverage in the above-described CVD method, lowering the temperature is inevitable. However, when the temperature is lowered, there is a problem that a large amount of carbon and oxygen in the organic liquid raw material remain as impurities in the thin film, thereby deteriorating the electrical characteristics of the thin film. Further, the heat treatment after the film formation causes a problem that impurities are desorbed and the film is peeled off. Furthermore, some organic liquid raw materials have a problem that the incubation time increases and the productivity is inferior.

  In order to solve such a problem, the cycle of forming a film of several to several tens of thousands under CVD conditions that improve the step coverage and the step of improving the film quality by plasma after the film formation are defined as one cycle. A CVD method for forming a thin film having a desired thickness by repeating a plurality of times has been studied.

  A so-called ALD (Atomic Layer Deposition) method has also been studied. In the ALD method, only a source gas obtained by vaporizing an organic liquid source is supplied to a substrate and adsorbed thereon, and then a reaction gas such as hydrogen or ammonia gas excited by plasma is supplied to the substrate to generate a thin film in one cycle. Then, a thin film having a desired thickness is formed by repeating this cycle a plurality of times.

  The plasma gas used in the above method needs to be supplied uniformly to the substrate. Therefore, a so-called parallel plate type capacitively coupled discharge plasma (CCP) source has been used as the plasma source.

  However, when a parallel plate capacitively coupled discharge plasma (CCP) source is used, an electric field is applied between the substrate and the plasma source. For this reason, there is a problem that ions and electrons existing in the plasma gas collide with the substrate and damage the base when the thin film is formed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate processing apparatus and a semiconductor manufacturing method in which the substrate is less damaged by plasma.

  According to one embodiment of the present invention, a processing chamber for processing a substrate, a raw material gas supply port for supplying a raw material gas into the processing chamber, and a reactive gas supply for supplying a reactive gas into the processing chamber. A plasma generator configured to convert the reaction gas into plasma by applying a high frequency voltage to the comb electrode, the plasma generator configured by at least one pair of opposing comb electrodes Is disposed between the substrate and the reaction gas supply port, and the comb-shaped electrodes constituting the plasma generation unit are each covered with an insulating tube whose tip is sealed in a spherical shape, A substrate processing apparatus is provided in which an insulating tube is cantilevered on the connection side with the transformer via an O-ring, and the periphery of the supporting portion of the insulating tube is purged with an inert gas.

  According to the present invention, it is possible to provide a substrate processing apparatus and a semiconductor manufacturing method in which a substrate is less damaged by plasma.

  An embodiment of the present invention will be described below with reference to the drawings.

In the drawings to be referred to, FIG. 1 is a schematic cross-sectional view (front) of a substrate processing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a substrate processing apparatus according to an embodiment of the present invention ( FIG. 3 is a schematic configuration diagram of a counter electrode as a plasma generating unit according to an embodiment of the present invention, and FIG. 3 (a) is a schematic configuration diagram of a pair of comb electrodes to which a transformer is connected. FIG. 5B is a cross-sectional enlarged view of a bar electrode included in a comb-shaped electrode and an insulator covering the bar electrode.
FIG. 4 is a substrate processing step diagram based on the ALD method as one step of the method of manufacturing a semiconductor device in one embodiment of the present invention, and FIG. 5 is a counter electrode in one embodiment of the present invention. It is a graph which illustrates the relationship between the distance from a substrate to a substrate, and the plasma density on a substrate.

(1) Configuration of Substrate Processing Apparatus A cross-sectional configuration diagram of a substrate processing apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

(A) Processing Chamber As shown in FIG. 1, a substrate processing apparatus according to an embodiment of the present invention includes a processing chamber 1 for processing a substrate. The processing chamber 1 is configured as a hermetically sealed container that can keep its interior airtight.

(B) Substrate loading / unloading exit A substrate 2 such as a silicon wafer or glass substrate to be processed is loaded into the processing chamber 1 or is unloaded from the processing chamber 1 to the side surface of the processing chamber 1. A substrate loading / unloading port 59 is provided.

  The substrate loading / unloading port 59 is connected to the vacuum substrate transfer chamber 58 via the gate valve 60. The gate valve 60 functions as a partition valve between the processing chamber 1 and the vacuum substrate transfer chamber 58. While the gate valve 60 is opened, the substrate 2 can be carried into the processing chamber 1 from the vacuum substrate transfer chamber 58, and the substrate 2 can be carried out from the processing chamber 1 to the vacuum substrate transfer chamber 58. I can do it.

(C) Processing Table A processing table 20 for holding the substrate 2 is provided inside the processing chamber 1. A susceptor 21 for supporting the substrate 2 is provided on the top of the processing table 20. A heater 22 as a heating unit for heating the substrate 2 is provided inside the processing table 20. The heater 22 is controlled using a temperature controller 23 so that the substrate 2 supported on the susceptor 21 has a predetermined temperature.

At the bottom of the processing chamber 1, lifting means 24 for holding the processing table 20 from the lower surface side is provided. The processing table 20 can be moved up and down in the processing chamber 1 by the lifting means 24.
When the substrate 2 is transported, the processing table 20 is lowered to the transport position indicated by the solid line in FIG. At this time, the push-up pin 62 provided at the bottom of the processing chamber 1 penetrates the through hole 63 provided so as to penetrate the processing table 20 and the susceptor 21 and protrudes from the surface of the susceptor 21. The push-up pins 62 protruding from the surface of the susceptor 21 support the substrate 2 that is carried into or out of the processing chamber 1.
Further, when the substrate 2 is processed, the processing table 20 moves up to the substrate processing position indicated by the dotted line in FIG. At this time, the push-up pin 62 is immersed from the surface of the susceptor 21, so that the susceptor 21 supports the substrate 2.

(D) Exhaust Line An exhaust port 10 for exhausting residual gas in the processing chamber 1 is provided at the lower part of the side surface of the processing chamber 1 opposite to the substrate loading / unloading port 59. A pressure controller 55, a vacuum pump 54, a raw material recovery trap 57, and an excluding device (not shown) are sequentially connected in series to the exhaust port 10 through an exhaust pipe 56.

  The pressure controller 55 functions to adjust the pressure in the processing chamber 1. The vacuum pump 54 functions to discharge the residual gas in the processing chamber 1. The raw material recovery trap 57 functions to recover the raw material gas component from the residual gas exhausted by the vacuum pump 54.

  A source gas bypass pipe 40 and a reaction gas bypass pipe 49, which will be described later, are connected to the exhaust pipe 56 between the pressure controller 55 and the vacuum pump 54, respectively.

(E) Source gas supply line A source gas supply line for supplying source gas is provided outside the processing chamber 1. The source gas supply line is connected to the upper portion of the processing chamber 1, and the connecting portion forms the source gas supply port 3. The configuration of the source gas supply line will be described below.

  The source gas supply line includes a source supply unit 25 for supplying a liquid source. The raw material supply unit 25 is configured so that the liquid raw material 28 can be stored therein.

A vaporizer 30 for vaporizing the liquid material is connected to the material supply unit 25 via a liquid material supply pipe 26. A liquid material flow rate control device 29 is provided between the material supply unit 25 and the vaporizer 30.
A pressure feed line 27 is connected to the raw material supply unit 25. The pressure feed line 27 supplies a pressurized inert gas such as He gas or Ar gas to the raw material supply unit 25.

  The liquid raw material 28 in the raw material supply unit 25 is supplied to the vaporizer 30 by the pressure of the inert gas supplied from the pressure feed line 27. At this time, the liquid material flow rate control device 29 controls the supply amount of the liquid material 28 supplied to the material supply unit 25.

  The liquid raw material 28 supplied to the vaporizer 30 is vaporized by the vaporizer 30 to generate a raw material gas. As source gases, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In , I, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Pb, Bi, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , Lu, and at least one kind of gas containing one or more elements can be used.

Note that an inert gas supply unit 33 is connected to the vaporizer 30 via an inert gas supply pipe 34 so that an inert gas can be supplied.
By supplying the liquid source 28 and the inert gas to the vaporizer 30 at the same time, the vaporization efficiency of the liquid source 28 can be increased. As the liquid raw material 28, for example, a raw material that becomes liquid when heated to about several tens of degrees Celsius at room temperature can be used. At this time, it is preferable to provide a heater for heating the raw material supply unit 25, the liquid raw material supply pipe 26, and the liquid raw material flow rate control device 29 to about several tens of degrees Celsius. As the inert gas, for example, Ar, He, N 2 or the like can be used.

  A gas flow rate control device 35 is provided between the inert gas supply unit 33 and the vaporizer 30. The gas flow rate control device 35 controls the amount of inert gas supplied to the vaporizer 30.

  The vaporizer 30 is connected to the upper part of the processing chamber 1 through a source gas supply pipe 31. A connecting portion between the source gas supply pipe 31 and the processing chamber 1 constitutes a source gas supply port 3.

  A valve 32 is provided in the source gas supply pipe 31 that connects the vaporizer 30 and the processing chamber 1. A source gas bypass pipe 40 is connected via a valve 39 upstream of the valve 32 of the source gas supply pipe 31 (that is, between the vaporizer 30 and the valve 32). The raw material gas bypass pipe 40 is connected to the exhaust pipe 56 as described above.

  Therefore, by closing the valve 39 and opening the valve 32, the source gas generated in the vaporizer 30 can be supplied to the processing chamber 1. On the other hand, by closing the valve 32 and opening the valve 39, the source gas generated in the vaporizer 30 can be directly discharged to the exhaust pipe 56 without being supplied to the processing chamber 1.

  On the other hand, on the downstream side of the valve 32 of the source gas supply pipe 31 (between the valve 32 and the processing chamber 1), a valve 38, a gas flow rate control device 37, and an inert gas supply unit 33 are connected to the purge gas supply pipe 36. Are sequentially connected in series.

  With this configuration, the valve 32 is closed and the valve 38 is opened while exhausting through the exhaust port 10, so that the downstream portion of the valve 32 of the source gas supply pipe 31 and the residual gas in the processing chamber 1 are removed. It can be replaced with an inert gas. The gas flow rate control device 37 functions as a flow rate controller for controlling the supply flow rate of the inert gas.

(F) Reaction gas supply line A reaction gas supply line for supplying reaction gas is provided outside the processing chamber 1. The reaction gas supply line is connected to the upper portion of the processing chamber 1, and the connection portion forms a reaction gas supply port 4. The configuration of the reaction gas supply line will be described below.

  The reactive gas supply line includes a reactive gas supply unit 41 for supplying reactive gas. The reactive gas supply unit 41 is connected to the upper part of the processing chamber 1 through a reactive gas supply pipe 42. As the reaction gas, at least one kind of gas containing any one or more elements of H, He, N, O, F, Ne, Cl, Ar, Kr, and Xe can be used.

  The reaction gas supply pipe 42 that connects the reaction gas supply unit 41 and the processing chamber 1 is provided with a valve 44. A reaction gas bypass pipe 49 is connected via a valve 48 upstream of the valve 44 of the reaction gas supply pipe 42 (that is, between the valve 44 and the gas flow rate control device 43). The reactive gas bypass pipe 49 is connected to the exhaust pipe 56 as described above.

  Accordingly, the reaction gas can be supplied to the processing chamber 1 by closing the valve 48 and opening the valve 44. On the other hand, by closing the valve 44 and opening the valve 48, the reaction gas can be directly discharged to the exhaust pipe 56 without being supplied to the processing chamber 1.

  On the other hand, on the downstream side of the valve 44 of the reaction gas supply pipe 42 (between the valve 44 and the processing chamber 1), a valve 47, a gas flow rate control device 46, and an inert gas supply unit 33 are connected to the purge gas supply pipe 45. Are sequentially connected in series.

  With this configuration, the valve 44 is closed, and the valve 47 is opened while exhausting through the exhaust port 10, whereby the downstream portion of the valve 44 of the reaction gas supply pipe 42 and the residual gas in the processing chamber 1 are removed. It can be replaced with an inert gas. The gas flow rate control device 46 functions as a flow rate controller for controlling the supply flow rate of the inert gas.

  A cleaning gas supply unit 50 is connected via a cleaning gas supply pipe 51 further downstream of the reaction gas supply pipe 42 (that is, further downstream than the connection portion with the purge gas supply pipe 45). The cleaning gas supply pipe 51 is provided with a valve 53, and the cleaning gas can be supplied into the processing chamber 1 by opening the valve 53. A gas flow rate control device 52 is provided upstream of the valve 53, and the gas flow rate control device 52 functions as a flow rate controller for controlling the supply flow rate of the cleaning gas.

(G) Shower Head A shower head 6 for supplying gas into the processing chamber 1 is provided below the source gas supply port 3 and the reaction gas supply port 4 and above the processing table 20. The shower head 6 includes a diffusion plate 7 for diffusing the gas supplied from the source gas supply port 3 or the reaction gas supply port 4, a buffer space 8 for dispersing the gas diffused by the diffusion plate 7, and a dispersion And a shower plate 9 for injecting the generated gas into the processing chamber 1 in the form of a shower.

(H) Plasma Generation Unit The counter electrode 5 as a plasma generation unit is provided below the shower head 6 and above the processing table 20. The counter electrode 5 functions to excite the reaction gas supplied from the shower head 6.

  As shown in FIG. 2A, the counter electrode 5 is composed of at least a pair of opposing comb-shaped electrodes 5a and 5b.

  Each comb-shaped electrode 5a, 5b has a configuration in which a plurality of rod-shaped electrodes 14 are arranged in a row with a predetermined interval. Here, since one end point of each rod-like electrode 14 is sequentially connected so as to be electrically conductive, and the other end point is opened, each of the comb electrodes 5a and 5b has a comb shape. I am doing.

  Each rod-like electrode 14 is constituted by a highly conductive metal, for example, a rod-like shape such as Al or Ni, or a twisted pair formed by combining two or more fine wires.

  Each rod-like electrode 14 is covered with an insulating tube 15. Then, as shown in FIG. 3B, the insulation covering the tip of each rod-like electrode 14 (that is, the end point of the rod-like electrode 14 that is not electrically connected and forms the comb-shaped mountain side). The tube 15 seals the rod-shaped electrode 14 so that the tip is spherical. The insulating tube 15 is formed of an insulator such as quartz or alumina.

  The pair of comb-shaped electrodes 5a and 5b constituting the counter electrode 5 are arranged so that the rod-shaped electrodes 14 of one comb-shaped electrode are inserted into the gaps where the rod-shaped electrodes 14 of the other comb-shaped electrode are arranged. Is done. And the overlapping part of the rod-shaped electrode 14 is formed on the same plane so that the whole upper surface of the board | substrate 2 may be covered. For example, when a silicon wafer is processed as the substrate 2, it is preferable that the overlapping portion of the rod-like electrode 14 is circular as shown in FIG.

  In the above, each insulating tube 15 is configured such that its root portion (that is, the electrically connected side) is cantilevered via an insulator such as an O-ring 5c. The O-ring 5 c is attached to a through hole 5 d that penetrates the side wall of the processing chamber 1. In order to ensure airtightness in the processing chamber 1, it is preferable that the O-ring 5 c be attached in multiple.

  Further, an inert gas such as pressurized He gas or Ar gas is purged from the purge port 5e at the root portion of each of the insulating pipes 15 described above. Thereby, it is comprised so that a reaction gas and source gas may not enter into the base part (namely, the side electrically connected) of the rod-shaped electrode 14. FIG.

  A secondary output 71 of the insulating transformer 70 is electrically connected to the comb electrodes 5a and 5b. A high frequency voltage is applied to the comb electrodes 5a and 5b. As a result, a high-frequency electric field is applied between the comb electrodes 5a and 5b, and the reaction gas existing in the upper surface region and the lower surface region of the counter electrode 5 can be plasma-excited.

(2) Manufacturing Method of Semiconductor Device Next, a substrate processing step as one step of the manufacturing method of the semiconductor device in one embodiment of the present invention will be described with reference to FIGS. This substrate processing step is performed by the substrate processing apparatus described above.

(A) Loading board (S1)
First, the processing table 20 is lowered to the position indicated by the solid line in FIG. 1 and the push-up pin 62 is protruded from the surface of the susceptor 21. Thereafter, the gate valve 60 is opened, the substrate 2 is carried into the processing chamber 1, and the substrate 2 is supported by the push-up pins 62. Thereafter, the elevating means 24 is operated to raise the processing table 20 to the substrate processing position indicated by the dotted line in FIG.

(B) Processing chamber exhaust (S2)
The valves 32, 44, 53, 39, 48 and the gate valve 60 are closed, and the valves 38, 44 are opened. Then, the vacuum pump 54 is operated to replace the residual gas in the processing chamber 1 with an inert gas. Note that the internal pressure of the processing chamber 1 is adjusted by the pressure controller 55.
Thereafter, the substrate 2 is heated to a predetermined temperature by energizing the heater 22.

(C) Supply of source gas (S3)
Subsequently, by supplying an inert gas to the pressure feed line 27, the liquid raw material 28 in the raw material supply unit 25 is supplied to the vaporizer 30, and the vaporizer 30 generates the raw material gas. At this time, an inert gas is supplied from the inert gas supply pipe 34 to the vaporizer 30 to promote the vaporization of the liquid raw material 28.

  Thereafter, the valves 38 and 47 are closed, the valve 32 is opened, and the source gas is supplied from the source gas supply port 3 into the processing chamber 1. The source gas supplied into the processing chamber 1 is diffused by the shower head 6, supplied uniformly to the surface of the substrate 2 supported on the processing table 20, and adsorbed on the surface of the substrate 2.

(D) Processing chamber exhaust (S4)
Thereafter, the valve 32 is closed, the valve 38 is opened, and the residual gas in the processing chamber 1 is replaced with an inert gas. At that time, the valve 39 is opened, and the raw material gas generated in the vaporizer 30 is directly discharged to the exhaust pipe 56 without being supplied to the processing chamber 1. A raw material gas component is recovered from the residual gas exhausted by the vacuum pump 54 using a raw material recovery trap 57.

(E) Supply of reaction gas (S5)
Subsequently, the valve 38 is closed, the valve 44 is opened, and the reaction gas is supplied from the reaction gas supply port 4 into the processing chamber 1. The reaction gas supplied into the processing chamber 1 is diffused by the shower head 6 and is uniformly supplied to the surface of the substrate 2 supported on the processing table 20.

(F) Plasmaization of reaction gas (S6)
Subsequently, a high frequency voltage is applied to the comb electrodes 5 a and 5 b constituting the counter electrode 5 using the insulating transformer 70. As a result, the plasma of the reactive gas existing in the upper surface region and the lower surface region of the counter electrode 5 is excited.

  Note that the density of the plasma-excited reactive gas supplied to the surface of the substrate 2 depends on the distance between the counter electrode 5 and the substrate 2. FIG. 5 is a graph illustrating the relationship between the distance from the counter electrode to the substrate and the plasma density on the substrate. That is, it is possible to adjust the plasma density on the substrate 2 by adjusting the height of the processing table 20.

As a result, the source gas adsorbed on the surface of the substrate 2 reacts with the plasma-excited reaction gas, and a thin film is formed on the surface of the substrate 2.
(G) Processing chamber exhaust (S7)
Thereafter, the application of the high frequency voltage to the comb electrodes 5a and 5b constituting the counter electrode 5 is stopped, and the plasma excitation of the reaction gas is interrupted. Then, the valve 44 is closed, the valve 47 is opened, and the residual gas in the processing chamber 1 is replaced with an inert gas. At that time, the valve 48 is opened, and the reaction gas is directly discharged to the exhaust pipe 56 without being supplied to the processing chamber 1.

(H) Repeat cycle (S8)
Subsequently, the steps (c) to (g) described above are repeated a plurality of times to form a thin film having a desired film pressure on the surface of the substrate 2.

(I) Unloading the substrate (S9)
When a thin film having a desired film pressure is formed on the surface of the substrate 2, the processing table 20 is lowered to a position indicated by a solid line in FIG. 1, and the substrate 2 is supported by the push-up pins 62. Then, after closing the valve 47, the gate valve 60 is opened, the substrate 2 is unloaded from the processing chamber 1, and the substrate processing step as one step of the semiconductor manufacturing apparatus is completed.

  In the above, when the thin film forming step is performed by the CVD method, the temperature of the substrate 2 is controlled so as to be in a temperature range in which the source gas is self-decomposed. In this case, the raw material gas is thermally decomposed, and a thin film of about several to several tens of kilometers (2, 3 to several atomic layers) is formed on the substrate 2. After that, when the supplied reaction gas is converted into plasma, impurities such as carbon atoms (C) and hydrogen atoms (H) are generated from several to several tens of liters of thin film formed on the substrate 2 due to the active species of the converted reaction gas. Is removed.

  Further, when the thin film forming step is performed by the ALD method, the temperature of the substrate 2 is controlled so as to be a temperature range in which the source gas does not self-decompose. In this case, the source gas is adsorbed on the substrate 2 without being thermally decomposed. After that, when the supplied reaction gas is turned into plasma, when the reaction gas is turned into plasma, the raw material adsorbed on the substrate 2 reacts with the active species of the reaction gas turned into plasma, and the substrate 2 has 1 kg or less (one atom). A thin film of about a layer or less) is formed. At this time, impurities such as carbon atoms (C) and hydrogen atoms (H) mixed in the thin film can be eliminated by the active species of the reaction gas.

In one embodiment of the present invention, specific conditions for performing the thin film forming step by the CVD method include, for example, when a HfO ₂ film is formed, a processing temperature of 350 to 500 ° C., a processing pressure of 50 to 200 Pa, Hf (MMP) ₄ (Hf (OC (CH ₃ ) ₂ CH ₂ OCH ₃ ) ₄ : tetrakis (1-methoxy-2-methyl-2-propoxy) -halfnium) as liquid raw material 28, supply flow rate 0. 01 to 0.1 sccm can be set to O ₂ as a reaction gas and a supply flow rate of 500 to 1500 sccm.

In one embodiment of the present invention, specific conditions for performing the thin film formation step by the ALD method include, for example, when forming a Ru film, a processing temperature of 150 to 300 ° C., a processing pressure of 10 to 200 Pa. As an organic metal liquid raw material as the liquid raw material 28, Ru (C ₂ H ₅ C ₅ H ₄ ) ((CH ₃ ) C ₅ H ₅ ): DER (2,4 dimethylpentadienylethylcyclopentadienylruthenium) The supply flow rate of 0.01 to 0.1 sccm can be set to a supply flow rate of 500 to 1500 sccm of hydrogen, oxygen, ammonia, or the like as the reactive gas.

(3) Effects According to One Embodiment of the Invention According to one embodiment of the present invention, the following effects can be obtained.

(A) When a conventional parallel plate capacitively coupled discharge plasma (CCP) source is used as the plasma source, an electric field is applied between the substrate 2 and the counter electrode 5. For this reason, there is a problem that ions and electrons existing in the plasma gas collide with the substrate and damage the base when the thin film is formed.
On the other hand, according to one embodiment of the present invention, since an electric field is not applied between the substrate 2 and the counter electrode 5, ions and electrons existing in the plasma reaction gas are accelerated by the electric field. There is no collision with the substrate 2. Therefore, it is possible to provide a substrate processing apparatus and a semiconductor manufacturing method in which the substrate 2 is less damaged by plasma.

(B) When a metal film is formed on the substrate 2 using plasma, a metal film may also be formed on the surface of the counter electrode 5. In this case, the electric field between the comb electrodes 5a and 5b is shielded by the metal film formed on the surface of the counter electrode 5, and there is a possibility that plasma cannot be generated.
On the other hand, according to one embodiment of the present invention, each rod-like electrode 14 constituting the comb electrodes 5a and 5b is covered with the insulating tube 15. Therefore, even if a metal film is formed on the surface of the insulating tube 15 covering the rod-shaped electrode 14, the space capacity between the comb electrodes 5a and 5b can be maintained, and plasma can be generated stably. I can do it.

(C) According to one embodiment of the present invention, the tip of the insulating tube 15 covering the comb electrodes 5a and 5b is sealed in a spherical shape. By sealing in a spherical shape in this way, concentration of plasma can be prevented and durability of the insulating tube 15 can be enhanced.

(D) According to one embodiment of the present invention, in the initial stage of film formation, the reaction is started with the source gas adsorbed on the surface of the substrate 2 in advance. Therefore, incubation time does not occur, and the productivity of the substrate processing process can be improved.

(E) According to one embodiment of the present invention, since the source gas and the plasma activated reaction gas are alternately supplied, one step of the method for manufacturing a semiconductor device having excellent step coverage and adhesion and high productivity The substrate processing process can be provided.

<Preferred embodiment of the present invention>
Hereinafter, desirable aspects of the present invention will be additionally described.

  A first aspect includes a processing chamber for processing a substrate, a raw material gas supply port for supplying a raw material gas into the processing chamber, a reactive gas supply port for supplying a reactive gas into the processing chamber, A plasma generator configured to form at least one pair of opposing comb electrodes and plasmatizing the reaction gas by applying a high frequency voltage to the comb electrodes, and the plasma generator includes the Comb electrodes disposed between the substrate and the reaction gas supply port, and the comb-shaped electrodes constituting the plasma generation unit are each covered with an insulating tube whose tip is sealed in a spherical shape, and the insulating tube is The substrate processing apparatus is such that the connection side with the transformer is cantilevered via an O-ring, and the periphery of the supporting portion of the insulating tube is purged with an inert gas.

  A second mode is the substrate processing apparatus according to the first mode, wherein the comb-shaped electrode of the plasma generation unit is connected to the secondary side output of the transformer and is not grounded.

  A third aspect is a method of manufacturing a semiconductor device implemented by the substrate processing apparatus according to the first or second aspect, the step of carrying the substrate into the processing chamber, and the supply onto the substrate Adjusting the distance between the substrate and the plasma generation unit so as to optimize the plasma density, supplying the source gas into the processing chamber and adsorbing it to the substrate, and reacting in the processing chamber The step of supplying a gas and the step of turning the reaction gas into plasma by applying a high-frequency voltage to the comb-shaped electrode of the plasma generating unit are set as one cycle, and this cycle is repeated a plurality of times, whereby a desired value is formed on the substrate. A method of manufacturing a semiconductor device, comprising: a step of forming a thin film having a thickness; and a step of unloading the substrate after the formation of the thin film from the processing chamber.

It is a section schematic diagram (front) of a substrate processing device concerning one embodiment of the present invention. It is a section schematic diagram (side) of a substrate processing device concerning one embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the counter electrode as a plasma production | generation part concerning one Embodiment of this invention, (a) is a schematic block diagram of a pair of comb electrode to which the transformer was connected, (b) It is a cross-sectional enlarged view of a rod-shaped electrode provided and an insulator covering the rod-shaped electrode. It is a substrate processing process figure based on ALD method as 1 process of the manufacturing method of the semiconductor device in one embodiment of this invention. It is a graph which illustrates the relationship between the distance from a counter electrode to a board | substrate in one embodiment of this invention, and the plasma density on a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Substrate 3 Raw material gas supply port 4 Reaction gas supply port 5 Counter electrode (plasma generation part)
5a, b Comb electrode 5c O-ring 15 Insulating tube 70 Insulating transformer 71 Secondary output

Claims (1)

A processing chamber for processing the substrate;
A source gas supply port for supplying source gas into the processing chamber;
A reaction gas supply port for supplying a reaction gas into the processing chamber;
A plasma generating unit that is composed of at least one pair of opposing comb-shaped electrodes, and converts the reactive gas into plasma by applying a high-frequency voltage to the comb-shaped electrodes;
Have
The plasma generation unit is disposed between the substrate and the reaction gas supply port,
The comb-shaped electrodes constituting the plasma generation unit are each covered with an insulating tube whose tip is sealed in a spherical shape,
The substrate processing apparatus, wherein the insulating tube is cantilevered on the connection side with the transformer via an O-ring, and the periphery of the supporting portion of the insulating tube is purged with an inert gas.