JP2012144786A - Neutral particle irradiation type cvd apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutral particle irradiation type CVD apparatus into which a raw material gas is introduced onto a wafer in parallel with neutral particles, and improves the in-plane uniformity of a film formed on the wafer.SOLUTION: The CVD apparatus includes: a cathode electrode 22 having a plurality of openings 22a through which neutral particles taken out from a plasma generation part 12 for generating plasma by exciting a noble gas with a coil 18, are introduced onto a wafer 14 within a reaction chamber 10; and a gas supply part 31 for supplying the raw material gas to the wafer 14 from above the wafer in parallel with the neutral particles.

Description

  The present invention relates to a CVD (Chemical Vapor Deposition) apparatus for depositing a film on a substrate, for example, a neutral particle irradiation type CVD apparatus for forming a film on a substrate using neutral particles.

  A neutral particle irradiation type CVD apparatus capable of forming a film having a predetermined molecular structure by suppressing dissociation of gas by high energy electrons or UV light has been developed (for example, see Patent Document 1).

Unlike the PE-CVD (Plasma Enhanced CVD) system, the neutral particle irradiation type CVD system does not irradiate the source gas and deposited film with the source gas and the deposited film. It is possible to synthesize a film without destroying it. In particular, the Si—OCH ₃ gas having a methoxy group has the weakest binding energy between the O and CH ₃ groups, and this portion can be selectively cut to synthesize a SiOCH ₃ Low-k film. is there. In this method, since the irradiation energy is relatively low, the Si—CH ₃ bond is hard to break, and the film can contain a high concentration of CH ₃ .

JP 2009-290025 A

  By the way, in the neutral particle irradiation type CVD apparatus, the source gas is supplied from the side of the wafer and is attached to the wafer surface while flowing on the wafer surface. A cathode electrode having a plurality of apertures is disposed between a plasma chamber for generating plasma and a reaction chamber in which a wafer is disposed, and ions accelerated by an electric field are neutralized in the process of passing through the aperture, and the wafer surface The material attached to the film is irradiated to form a film having a predetermined molecular structure.

  However, in the neutral particle irradiation type CVD apparatus, the source gas is supplied from the side of the wafer and flows toward the gas outlet. For this reason, the film formed on the wafer is formed thicker on the side near the supply portion of the source gas than on the side away from the supply portion. Therefore, it is difficult to ensure in-plane uniformity of the formed film. Recently, this tendency is becoming remarkable as the wafer diameter increases.

  For this reason, it is conceivable to apply a shower head used as a gas supply means of a general PE-CVD apparatus to a neutral particle irradiation type CVD apparatus. However, since the incident direction of the neutral particle beam is the direction from the upper surface of the wafer toward the wafer surface, it is difficult to install a shower head here.

  Embodiments of the present invention provide a neutral particle irradiation type CVD apparatus capable of introducing a source gas into a wafer in parallel with a neutral particle beam and improving the in-plane uniformity of a film formed on the wafer. It is something to try.

  A neutral particle irradiation type CVD apparatus according to an embodiment of the present invention includes a plasma generation unit that generates plasma by exciting a rare gas, and takes out neutral particles from the plasma generated by the plasma generation unit. A cathode electrode having a plurality of first openings to be introduced into a wafer, and a gas supply unit for supplying a raw material gas to the wafer in parallel with the neutral particles from directly above the wafer.

  According to an embodiment of the present invention, a neutral particle irradiation type CVD apparatus capable of introducing a source gas into a wafer in parallel with a neutral particle beam and improving the in-plane uniformity of a film formed on the wafer. Can provide.

Sectional drawing which shows 1st Embodiment of the neutral particle irradiation type CVD apparatus of this invention. The top view which shows the gas supply part shown in FIG. 3A and 3B are cross-sectional views of the pipe shown in FIG. FIG. 3 is a diagram illustrating a relationship between first and second openings illustrated in FIG. 2 and a positional relationship between a cathode electrode, a gas supply unit, and a wafer. Sectional drawing which shows the 2nd Embodiment of this invention and shows only a part of neutral particle irradiation type | mold CVD apparatus. Sectional drawing which shows the 3rd Embodiment of this invention and shows only a part of neutral particle irradiation type | mold CVD apparatus. The top view which shows the 1st modification of a gas supply part. The top view which shows the 2nd modification of a gas supply part. The top view which shows the 3rd modification of a gas supply part. The top view which shows the 4th modification of a gas supply part. The top view which shows the 5th modification of a gas supply part. FIG. 12A is a sectional view showing a fourth embodiment of the neutral particle irradiation type CVD apparatus of the present invention, and FIG. 12B is a plan view showing the cathode electrode of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals.

  FIG. 1 shows a neutral particle irradiation type CVD apparatus according to an embodiment of the present invention. In FIG. 1, a neutral particle beam generating unit 11 is provided, for example, at an upper portion of a CVD reaction chamber (hereinafter simply referred to as a reaction chamber) 10.

  A stage 13 is provided in the reaction chamber 10, and a semiconductor wafer (hereinafter referred to as a wafer) 14 as a substrate to be processed is placed on the stage 13. The stage 13 has a temperature control device (not shown), and the wafer 14 is controlled to a predetermined temperature. The reaction chamber 10 has a gas inlet 15 through which a source gas is introduced and an exhaust mechanism 16. The reaction chamber 10 is maintained at a predetermined pressure by the exhaust mechanism 16. The source gas is guided directly above the wafer 14 on the stage 13 through a gas supply unit 31 communicated with the gas inlet 15 and is ejected onto the wafer from an opening described later.

  The neutral particle beam generator 11 has a plasma chamber 12 made of, for example, quartz. A gas introduction port 17 is provided in the upper part of the plasma chamber 12, and a rare gas such as argon, helium, krypton, or the like is introduced into the plasma chamber 12 from the gas introduction port 17. A coil 18 is wound around the plasma chamber 12. One end of the coil 18 is grounded, and the other end is connected to the high frequency source 19. An anode electrode 20 as an upper electrode is provided inside and above the plasma chamber 12, and the anode electrode 20 is connected to the positive electrode of the DC power source 21 and the high-frequency source 19 through the switch SW 1. Further, a cathode electrode 22 as a lower electrode is provided at the lower part of the plasma chamber 12 and at the boundary with the reaction chamber 10. The cathode electrode 22 is connected to the negative electrode of the DC power source 21 via the switch SW2. The DC power supply 21 is a variable power supply, and the DC power supply 21 can change the electric field between the anode electrode 20 and the cathode electrode 22.

  The cathode electrode 22 is made of, for example, carbon and has a plurality of openings (first openings) 22a. The opening 22a has an aspect ratio (ratio between the thickness of the cathode electrode 22 and the diameter of the opening 22a) set in a range of, for example, 10 or more and 20 or less, and an opening ratio (a plurality of surface areas of the cathode electrode 22 with respect to the surface area). The ratio of the opening area by the opening 22a) is set in a range of, for example, 50% or less and 30% or more.

  The cathode electrode 22 is required to neutralize and pass positive charged particles and to block electrons, UV light, or photons generated from the plasma, so that the aspect ratio and the aperture ratio of the opening 22a are defined. Yes.

  Furthermore, it is necessary to maintain a pressure difference between the reaction chamber 10 and the plasma chamber 12 in order to prevent the gas in the reaction chamber 10 from flowing into the plasma chamber 12. Specifically, the pressure in the reaction chamber 10 is set to 100 mmTorr or more, for example, and the pressure in the plasma chamber 12 is set to 1 Torr or more, for example. Therefore, in order to suppress the inflow of gas from the reaction chamber 10 to the plasma chamber 12, it is necessary to set the pressure difference between the plasma chamber 12 and the reaction chamber 10 to 10 times or more. In order to maintain such a pressure difference, it is preferable that the opening ratio of the opening 22a of the cathode electrode 22 is about 30%.

  Further, in the reaction chamber 10, the aforementioned gas supply unit 31 is provided between the cathode electrode 22 and the stage 13 on which the wafer 14 is placed. The gas supply unit 31 is provided in the reaction chamber 10 as a space not in direct contact with plasma. Specifically, the gas supply unit 31 is held on the side wall of the reaction chamber 10. The gas supply unit 31 can supply the source gas to the surface of the wafer 14 from directly above the wafer 14 and can be introduced to the surface of the wafer 14 without interfering with the neutral particles generated by the neutral particle beam generation unit 11. It is made into the composition.

  FIG. 2 shows an example of the gas supply unit 31. The gas supply unit 31 includes, for example, a ring-shaped first pipe 31a and a plurality of second pipes 31b. The first and second pipes 31a and 31b can be formed of, for example, quartz, ceramic, stainless steel (SUS), carbon, aluminum, or a composite material thereof.

  The plurality of second pipes 31b are arranged in a mesh shape inside the ring of the first pipe 31a. A plurality of second openings 31c are formed by the second pipe 31b and the first pipe 31a. The opening area of the second opening 31 c is formed larger than the opening area of the first opening 22 a provided in the cathode electrode 22. Specifically, the opening area of the second opening 31c is set to, for example, 10 times or more the opening area of the first opening 22a. For this reason, the neutral particle beam generated by the neutral particle beam generator 11 can be uniformly introduced onto the surface of the wafer 14 through the second opening 31c.

  Further, a third opening 31d for ejecting the source gas is provided at, for example, an intersection of the plurality of second pipes 31b. These third openings 31 d are arranged so as to face the wafer 14, and the raw material gas can be uniformly supplied from directly above the wafer 14 to the surface of the wafer 14.

  In the example shown in FIG. 2, the distance L1 between the third openings 31d farthest away is, for example, 20 mm, and the distance L2 between the third openings 31d closest to each other is, for example, 50 mm. However, the present invention is not limited to this, and can be set according to the diameter of the wafer to be processed.

  3A shows a cross section of the first pipe 31a, and FIG. 3B shows a cross section of the second pipe 31b. The source gas introduced into the gas supply unit 31 from the gas inlet 15 flows through the first and second pipes 31a and 31b.

  As shown in FIG.3 (b), the outer diameter L3 of the 2nd pipe 31b is 10 mm or less, for example, and it is desirable that it is as small as possible so that introduction of neutral particles may not be prevented. The inner diameter L4 of the second pipe 31b is, for example, 5 mm or more, and is desirably as large as possible in order to reduce conductance loss in gas supply. Furthermore, the diameter of the 3rd opening part 31d is set to 0.5 mm or more and 1 mm or less, for example. As a result, the same flow rate of gas can flow from all the third openings 31d. That is, by determining the relationship between the inner diameter L2 of the second pipe 31b and the diameter of the third opening 31d as described above, the second pipe 31b has a conductance 10 times or more that of the third opening 31d. It is possible to secure the pressure loss in the second pipe 31b to the minimum.

  Further, the ejection angle of the source gas ejected from the third opening 31d is in the range of 90 to 45 degrees with respect to the surface of the wafer 14, for example.

  4 shows the positional relationship between the cathode electrode 22, the gas supply unit 31, and the wafer 14. In FIG. 4, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals.

  In FIG. 4, the plurality of second pipes 31 b of the gas supply unit 31 should not interfere with neutral particles introduced into the wafer 14 from the first opening 22 a provided in the cathode electrode 22. For this reason, as described above, the opening area of the second opening 31 c of the gas supply unit 31 is set to be 10 times or more that of the first opening 22 a of the cathode electrode 22. Specifically, when the diameter D1 of the first opening 22a is 1 mm, for example, the length D2 of one side of the rectangular second opening 31c is set to 10 mm or more, for example, 45 mm.

  Furthermore, the distance L5 between the cathode electrode 22 and the gas supply unit 31 and the distance L6 between the gas supply unit 31 and the wafer 14 are set as follows. That is, for example, when the thickness of the cathode electrode 22 is 10 mm, for example, and the diameter of the first opening 22a is 1 mm, the neutral particles ejected from the first opening 22a are +5 degrees with respect to the vertical direction, − Assuming that the opening has an extent of 5 degrees (90 degrees ± 5 degrees), and assuming that the opening area of the second opening 31c is 10 times the opening area of the first opening 22a, the gas supply The distance L6 between the part 31 and the wafer 14 needs to be at least twice the distance between the cathode electrode 22 and the gas supply part 31 and the distance L5. Specifically, when L5 is 10 mm or more, L6 is set to 20 mm or more.

  In the above configuration, the operation of the neutral particle irradiation type CVD apparatus will be described.

  In the neutral particle irradiation type CVD apparatus of the present embodiment, the neutral particle beam generation unit 11 generates a neutral particle beam whose energy is controlled using a rare gas. The generated neutral particle beam is irradiated to a gas as a precursor in the reaction chamber 10 and polymerized by controlling dissociation of molecules constituting the gas, so that a film having a desired molecular structure is formed on the substrate. .

  First, the pressure of the plasma chamber 12 is set to 1 Torr or more, for example, and a rare gas, for example, argon gas is introduced into the plasma chamber 12. In this state, the switch SW <b> 1 is turned on, and high frequency power is supplied from the high frequency source 19 to the coil 18. For example, the high-frequency power has a frequency of 13.56 MHz, a voltage of 500 V, and a power of 1 kW. Electrons in the plasma chamber 12 are accelerated by the high-frequency electric field generated by the coil 18 and collide with the argon gas, and the gas is decomposed to generate plasma.

  In this state, when the switch SW2 is turned on, an electric field is generated between the anode electrode 20 and the cathode electrode 22, and positive charged particles in the plasma are accelerated by the electric field. The positively charged particles are neutralized by supplying electrons at the cathode electrode 22 to generate neutral particles (NB). The neutral particles are guided into the reaction chamber 10 through the plurality of first openings 22a. At this time, electrons, UV light, or photons generated in the plasma source are shielded by the cathode electrode 22 and do not reach the reaction chamber 10.

  The energy of neutral particles guided to the reaction chamber 10 is controlled by the acceleration voltage of ions generated in the plasma, and this acceleration voltage is varied by controlling the DC power source 21. The neutral particles are introduced into the wafer 14 through the second opening 31 c of the gas supply unit 31. The wafer 14 is placed on the stage 13 and the temperature is controlled.

  On the other hand, the source gas supplied from the gas inlet 15 to the gas supply unit 31 is jetted onto the upper surface of the wafer 14 from the third opening 31d. In other words, the source gas is jetted onto the wafer 14 from the third opening 31d disposed immediately above the wafer 14 substantially in parallel with the neutral particle beam. The source gas is, for example, DMDMOS (dimethyldimethoxysilane) as a precursor of the low-k film, and is introduced into the DMDMOS from the first opening 22 a of the plasma chamber 12 through the second opening 31 c of the supply unit 31. Neutral particles collide. The kinetic energy is converted into thermal energy by the collision of neutral particles. With the assistance of the thermal energy, dissociation of predetermined bonds of gas molecules adsorbed on the substrate is promoted, and the activated gas is sequentially deposited on the wafer 14 by causing a polymerization reaction.

  In this manner, a low-k film made of SiOC is deposited on the wafer 14 using DMDMOS as a precursor. The precursor is not limited to DMDMOS, and Si-based compounds such as MTMOS (methyltrimethoxysilane) can also be used.

  According to the first embodiment, the first opening 22a of the cathode electrode 21 is neutralized by accelerating ions, and the third opening 31d of the gas supply unit 31 is located below the first opening 22a. The material gas is uniformly supplied to the wafer 14 from directly above the wafer 14 substantially in parallel with the neutral particle beam. In addition, the opening area of the second opening 31c provided in the gas supply unit 31 is set to 10 times or more the opening area of the first opening 22a. For this reason, the neutral particle beam can be introduced onto the wafer 14 without disturbing the irradiation path of the neutral particle beam irradiated from the first opening 22a. Therefore, since the source gas can be supplied uniformly on the surface of the wafer 14 and neutral particles can be uniformly irradiated on the surface of the wafer 14, a uniform film thickness can be formed on the surface of the wafer 14. It is possible to form a film having the same.

  In addition, according to the above configuration, the source gas can be uniformly supplied to the wafer surface and the neutral particle beam can be sufficiently introduced. A film having a uniform film thickness can be formed on this wafer, and the yield can be improved.

(Second Embodiment)
FIG. 5 shows a second embodiment. In FIG. 5, the plasma chamber 12 and the like are omitted.

  In the first embodiment, the gas supply unit 31 is held on the side wall of the reaction chamber 10. In contrast, in the second embodiment, the gas supply unit 31 is supported by, for example, three support bodies 41 (only two are shown in FIG. 5). These supports 41 can be formed of, for example, ceramic, quartz, stainless steel (SUS), for example, similarly to the gas supply unit 31. These supports 41 have a pipe shape, one end is disposed at the bottom of the reaction chamber 10, and the other end is provided on the first pipe 31 a of the gas supply unit 31. That is, the pipe-shaped support body 41 communicates with the first pipe 31 a of the gas supply unit 31, and the raw material gas is introduced into the gas supply unit 31 through these pipes 41.

  According to the second embodiment, the same effect as that of the first embodiment can be obtained.

(Third embodiment)
FIG. 6 shows a third embodiment. In the third embodiment, each support body 41 shown in the second embodiment has an elevating mechanism. That is, the support body 41 is composed of, for example, two first and second pipes 41a and 41b having different diameters, and the second pipe 41b is inserted into the first pipe 41a. The first pipe 41a can be moved up and down in the directions indicated by arrows A and B with respect to the second pipe 41b. Specifically, for example, the first pipe 41a is screwed to the second pipe 41b. In this state, when the second pipe 41b is rotated around the axis thereof in the illustrated arrows C and D directions by the power (not shown), the first pipe 41a is illustrated with respect to the second pipe 41b. It is moved in the A and B directions.

  The elevating mechanism is not limited to the above-described configuration, and the first pipe 41a can be moved with respect to the second pipe 41b using, for example, a linear motor.

  According to the third embodiment, by allowing the first pipe 41a to move with respect to the second pipe 41b, the distance between the wafer 14 and the gas supply unit 31, the gas supply unit 31 and the cathode electrode 22 is achieved. And the distance can be adjusted. For this reason, the gas supply unit 31 can be set at an optimum position between the wafer 14 and the cathode electrode 22. Therefore, the uniformity of the film formed on the wafer 14 can be further improved.

  Further, the gas supply unit 31 can be moved with respect to the wafer 14. Therefore, a required space can be formed when the wafer 14 is transported to the stage 13.

  7 to 11 show modified examples of the gas supply unit 31. 7 to 11, the material of the first and second pipes 31a and 31b, the diameter of the pipe, and the opening area of the third opening 31d are the same as those in the first embodiment.

  In the gas supply unit 31 shown in FIG. 2, the second pipes 31b are arranged in a mesh shape, and a third opening 31d is formed at the intersection of the second pipes 31b.

(First modification)
In contrast, in the first modification shown in FIG. 7, the second pipe 31b of the gas supply unit 31 includes a plurality of second pipes 31b arranged in parallel, and the wafer 14 of each second pipe 31b. A third opening 31d is formed at a position opposite to. The opening area of the second opening 31c formed by the adjacent second pipes 31b and the second pipe 31b and the first pipe 31a is set to be 10 times or more the opening area of the first opening 22a. ing.

  Also according to the first modified example, the source gas can be uniformly supplied to the surface of the wafer 14 from directly above the wafer 14. Moreover, the opening area of the second opening 31c can be made larger than that of the first embodiment. For this reason, the neutral particle beam can be efficiently introduced into the wafer 14, and a film having a uniform film thickness can be formed on the wafer 14.

(Second modification)
In the second modified example shown in FIG. 8, the second pipe 31b is constituted by a linear pipe 31b-1 and a ring-shaped pipe 31b-2. The straight pipe 31b-1 is arranged corresponding to the diameter of the first pipe 31a, and the ring-shaped pipe 31b-2 is arranged concentrically with the first pipe 31a. The linear pipe 31b-1, the ring-shaped pipe 31b-2, and the first pipe 31a are in communication. The ring-shaped first and second pipes 31 a and 31 b-2 are provided with a plurality of third openings 31 d so as to face the wafer 14. A third opening 31 d is formed facing the center of the wafer 14.

  Also according to the second modification, the source gas is supplied from the third opening 31d provided in the ring-shaped first and second pipes 31a and 31b-2 and the linear second pipe 31b-1. It is possible to supply the wafer 14 uniformly from directly above the wafer 14. In addition, by forming the second pipe 31b-2 in a ring shape, the opening area of the second opening 31c can be increased as compared with the first embodiment. For this reason, a neutral particle beam can be efficiently introduced into the wafer 14. Therefore, it is possible to form a film having a uniform film thickness on the surface of the wafer 14.

(Third Modification)
In the third modified example shown in FIG. 9, the second pipe 31b is composed of a plurality of linear pipes 31b-3 and 31b-4. These pipes 31b-3 and 31b-4 are arranged radially inside the first pipe 31a. That is, one end of the plurality of pipes 31 b-3 is provided on the first pipe 31 a, and the other end of the plurality of pipes 31 b-3 is disposed above the wafer 14 and at the same position from the center of the wafer 14. In addition, the third openings 31 d provided in the plurality of pipes 31 b-3 are opposed to the surface of the wafer 14.

  Further, the second pipe 31b-4 has a length substantially equal to the radius of the ring-shaped first pipe 31a. One end of the second pipe 31 b-4 is provided in the first pipe 31 a, and the other end is located at the center of the wafer 14. A third opening 31 d provided at the other end of the second pipe 31 b-4 is opposed to the central portion of the wafer 14.

  Also according to the third modified example, it is possible to uniformly supply the source gas to the wafer 14 from directly above the wafer 14. In addition, since the opening area of the second opening 31c can be made larger than that in the first embodiment, a film having a uniform film thickness can be formed on the surface of the wafer.

  The first to third modifications can be applied to the first to third embodiments.

(Fourth modification)
FIG. 10 shows a fourth modification. The fourth modification is a modification of the third opening 31d, and shows a case where the fourth modification is applied to the gas supply unit 31 shown in the first modification.

  In FIG. 10, each second pipe 31b is provided with a plurality of third openings 31d. That is, in the longitudinal direction of the second pipe 31b, two third openings 31d are provided at predetermined intervals. The two third openings 31d are arranged at the same position in the longitudinal direction of the second pipe 31b. That is, as indicated by E in FIG. 10, at the position facing the wafer 14 of the second pipe 31b, two third openings 31d-1 are provided at a predetermined interval around the axis of the second pipe 31b. , 31d-2 is provided. The opening directions of the two third openings 31d-1 and 31d-2 are inclined by, for example, about 15 degrees to 20 degrees with respect to the vertical line.

  According to the fourth modification, two third openings 31d-1 and 31d-2 are provided in each second pipe 31b of the gas supply unit 31 with a predetermined interval. For this reason, the source gas can be supplied more uniformly to the wafer 14. Therefore, the film thickness of the formed film can be made more uniform.

(Fifth modification)
FIG. 11 shows a fifth modification. The fifth modification is a further modification of the fourth modification. That is, in the fourth modification, the two third openings 31d-1 and 31d-2 are arranged at the same position in the longitudinal direction of each second pipe 31b. On the other hand, in the fifth modification example, the two third openings 31d-1 and 31d-2 are arranged at different positions in the longitudinal direction of the second pipes 31b. Similar to the fourth modification, the opening directions of the two third openings 31d-1 and 31d-2 are inclined by, for example, about 15 degrees to 20 degrees with respect to the vertical line.

  According to the fifth modified example, the third openings 31d-1 and 31d-2 provided in the second pipes 31b are arranged apart from each other in the longitudinal direction of the second pipe 31b. For this reason, it is possible to supply the source gas evenly to the wafer 14, and the film thickness of the formed film can be made uniform.

  The fourth and fifth modifications can be applied to the first to third embodiments and the first to third modifications.

(Fourth embodiment)
12 (a) and 12 (b) show a fourth embodiment. In the first to third embodiments, the gas supply unit 31 is provided between the cathode electrode 22 and the wafer 14. In contrast, in the fourth embodiment, the gas supply unit 31 is incorporated in the cathode electrode 22.

  That is, in FIG. 12A, the cathode electrode 51 is made of a porous conductive material, for example, porous graphite. The cathode electrode 51 is formed with a plurality of first openings 51 a through which neutral particles are extracted from the plasma generated in the plasma chamber 12 and introduced into the wafer in the reaction chamber 10. Further, in the cathode electrode 51, for example, a plurality of ring-shaped pipes 51b constituting a gas supply unit are formed concentrically. The plurality of pipes 51 b communicate with the gas inlet 52. The plurality of pipes 51b are formed in the porous material. For this reason, the raw material gas introduced into these pipes 51b is introduced into the reaction chamber 10 through a plurality of holes provided in the pipes 51b.

  The cathode electrode 51 having the above configuration is formed, for example, as follows. First, a plurality of ring-shaped grooves constituting a plurality of pipes 51 b and a linear groove that connects these grooves and constitutes a gas introduction port 52 are first members made of porous graphite constituting the cathode electrode 51. It is formed on the upper surface side of 51-1. Thereafter, a second member 51-2 made of porous graphite as a cover is attached to the upper surface of the first member 51-1. As a result, a plurality of pipes 51b and a gas introduction port 52 communicated therewith are formed. Next, a plurality of first openings 51a penetrating the first and second members 51-1 and 51-2 are formed in a region located between the plurality of pipes 51b. In this way, the cathode electrode 51 is formed.

  In addition, a conductive film is formed on the inner surfaces of the plurality of first openings 51a and the surface of the second member 51-2 to close the holes in these portions, and the holes are formed only in the bottoms of the plurality of pipes 51b. Preferably it is present.

  In the above configuration, the operation of the neutral particle irradiation type CVD apparatus will be described.

  In the configuration shown in FIG. 12A, the distance between the cathode electrode 51 and the wafer 14 is set to 20 mm, for example. In this state, plasma is generated in the plasma chamber 12 as in the first embodiment. Positive charged particles in the plasma are accelerated by the electric field between the anode electrode 20 and the cathode electrode 22. The positively charged particles are neutralized by supplying electrons at the cathode electrode 22 to generate neutral particles (NB). The neutral particles are guided into the reaction chamber 10 through the plurality of first openings 51a.

  On the other hand, the source gas supplied from the gas inlet 52 to the plurality of pipes 51 b is introduced into the reaction chamber 10 through the plurality of holes formed in the lower surface of the cathode electrode 51. That is, the raw material gas introduced into the reaction chamber 10 from the lower surface of the cathode electrode 51 is introduced from the top of the wafer 14 to the surface of the wafer 14 in parallel with the neutral particle beam. The kinetic energy of the source gas is converted into thermal energy by the collision of neutral particles. With the assistance of the thermal energy, dissociation of predetermined bonds of gas molecules adsorbed on the substrate is promoted, and the activated gas is sequentially deposited on the wafer 14 by causing a polymerization reaction.

  According to the fourth embodiment, the cathode electrode 51 is formed of a porous material, has the plurality of first openings 51a for introducing neutral particles into the reaction chamber 10, and supplies the source gas therein. A plurality of pipes 51b to be introduced are provided, and a raw material gas is introduced into the reaction chamber 10 from a plurality of holes formed in the plurality of pipes 51b. Therefore, also in the fourth embodiment, as in the first to third embodiments, the source gas can be introduced into the surface of the wafer 14 from directly above the wafer 14 in parallel with the neutral particle beam. Therefore, a film having a uniform film thickness can be formed on the wafer 14.

  In the fourth embodiment, the cathode electrode is formed of a conductive porous material. However, the present invention is not limited to this. For example, a plurality of openings are formed on the surface of the plurality of pipes 51b facing the wafer 14. It may be formed. In this case, another conductive material can be used instead of the porous material.

  In the first to fourth embodiments, the gas flow path is a single system including the gas inlets 15 and 52. However, the present invention is not limited to this, and the gas flow path system may be composed of two or more systems. When the gas flow path system is composed of two or more systems, a plurality of gases can be supplied uniformly at the same time.

  In addition, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 10 ... Reaction chamber, 14 ... Wafer, 12 ... Plasma chamber, 22, 51 ... Cathode electrode, 22a ... First opening, 31 ... Gas supply part, 31a ... First pipe, 31b, 31b-1, 31b-2 31b-3, 31b-4 ... second pipe, 31c ... second opening, 31d, 31d-1, 31d-2 ... third opening, 41 ... support, 41a, 41b ... first, second Pipe, 51a, first opening, 51b, pipe.

Claims (6)

A plasma generator for generating a plasma by exciting a rare gas;
An electrode having a plurality of first openings for extracting neutral particles from the plasma generated by the plasma generator and introducing them into a wafer in a reaction chamber;
A neutral particle irradiation type CVD apparatus comprising: a gas supply unit that supplies a raw material gas to the wafer in parallel with the neutral particles from directly above the wafer.   The gas supply unit is provided between the electrode and the wafer, and discharges the plurality of second openings through which the neutral particles introduced from the first opening of the electrode pass, and the source gas. The neutral particle irradiation type CVD apparatus according to claim 1, further comprising a plurality of third openings.   The neutral particle irradiation type CVD apparatus according to claim 2, wherein the second opening has an opening area that is 10 times or more that of the first opening.   The neutral particle irradiation according to claim 3, wherein a distance between the electrode and the gas supply unit is set to 10 mm or more, and a distance between the gas supply unit and the wafer is set to 20 mm or more. Type CVD equipment.   The gas supply unit has a ring-shaped first pipe having a first diameter and a second diameter smaller than the first diameter communicated with the first and having the plurality of third openings. The neutral particle irradiation type CVD apparatus according to claim 4, further comprising at least one second pipe.   The electrode is formed of a porous material and has a pipe into which the source gas is introduced, and the source gas in the pipe is supplied to the wafer from a hole in the porous material. 1. A neutral particle irradiation type CVD apparatus according to 1.

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