JP4113896B2 - Plasma processing equipment - Google Patents

Description

  The present invention generally relates to a plasma processing apparatus, and more particularly to a microwave plasma processing apparatus.

  The plasma processing step and the plasma processing apparatus are used in the manufacture of ultra-miniaturized semiconductor devices having a gate length close to or less than 0.1 μm, which are called so-called deep sub-micron elements or deep sub-quarter micron elements, and liquid crystal display devices. This is an indispensable technique for manufacturing a high-resolution flat panel display device.

  Various plasma excitation methods have been used in the past as plasma processing devices used in the manufacture of semiconductor devices and liquid crystal display devices. In particular, parallel plate high frequency excitation plasma processing devices or inductively coupled plasma processing devices are generally used. Is. However, these conventional plasma processing apparatuses have a problem that it is difficult to perform a uniform process over the entire surface of the substrate to be processed at a high processing speed, that is, a throughput because the plasma formation is non-uniform and the region where the electron density is high is limited. Has a point. This problem is particularly serious when processing a large-diameter substrate. In addition, these conventional plasma processing apparatuses have some essential problems such as damage to semiconductor elements formed on the substrate to be processed due to high electron temperature, and large metal contamination due to sputtering of the processing chamber wall. Have. For this reason, it is becoming difficult for conventional plasma processing apparatuses to meet strict requirements for further miniaturization of semiconductor devices and liquid crystal display devices and further improvement of productivity.

  On the other hand, a microwave plasma processing apparatus that uses high-density plasma excited by a microwave electric field without using a DC magnetic field has been proposed. For example, microwaves are radiated into a processing vessel from a planar antenna (radial line slot antenna) having a large number of slots arranged to generate uniform microwaves, and gas in the vacuum vessel is generated by the microwave electric field. There has been proposed a plasma processing apparatus configured to excite plasma by exciting the plasma. For example, see JP-A-9-63793. With microwave plasma excited by such a method, a high plasma density can be realized over a wide region directly under the antenna, and uniform plasma treatment can be performed in a short time. In addition, the microwave plasma formed by such a method excites the plasma by the microwave, so that the electron temperature is low, and damage to the substrate to be processed and metal contamination can be avoided. Furthermore, since uniform plasma can be easily excited even on a large-area substrate, it is possible to easily cope with a manufacturing process of a semiconductor device using a large-diameter semiconductor substrate and a large-sized liquid crystal display device.

  1A and 1B show a configuration of a conventional microwave plasma processing apparatus 100 using such a radial line slot antenna. However, FIG. 1A is a sectional view of the microwave plasma processing apparatus 100, and FIG. 1B is a diagram showing a configuration of a radial line slot antenna.

  Referring to FIG. 1A, the microwave plasma processing apparatus 100 includes a processing chamber 101 that is exhausted from a plurality of exhaust ports 116, and a holding table 115 that holds a substrate to be processed 114 is formed in the processing chamber 101. ing. In order to achieve uniform exhaust of the processing chamber 101, a ring-shaped space 101A is formed around the holding table 115, and the plurality of exhaust ports 116 are connected at equal intervals so as to communicate with the space 101A. In other words, the processing chamber 101 can be uniformly evacuated through the space 101A and the exhaust port 116 by being formed symmetrically with respect to the substrate to be processed.

  A large number of openings 107 made of a low-loss dielectric material are formed on the processing chamber 101 as a part of the outer wall of the processing chamber 101 at a position corresponding to the substrate 114 to be processed on the holding table 115. A plate-like shower plate 103 is formed via a seal ring 109, and a cover plate 102 made of a low-loss dielectric is also provided outside the shower plate 103 via another seal ring 108. .

  A plasma gas passage 104 is formed on the upper surface of the shower plate 103, and each of the plurality of openings 107 is formed to communicate with the plasma gas passage 104. Further, a plasma gas supply passage 108 communicating with the plasma gas supply port 105 provided on the outer wall of the processing vessel 101 is formed inside the shower plate 103, and is supplied to the plasma gas supply port 105. A plasma gas such as Ar or Kr is supplied from the supply passage 108 to the opening 107 through the passage 104, and from the opening 107 to the space 101B immediately below the shower plate 103 inside the processing vessel 101. Released at a substantially uniform concentration.

  On the processing container 101, a radial line slot antenna 110 having a radiation surface shown in FIG. 1B is provided outside the cover plate 102 at a distance of 4 to 5 mm from the cover plate 102. The radial line slot antenna 110 is connected to an external microwave source (not shown) via a coaxial waveguide 110A, and excites the plasma gas discharged into the space 101B by the microwave from the microwave source. To do. A gap between the cover plate 102 and the radiation surface of the radial line slot antenna 110 is filled with air.

  The radial line slot antenna 110 includes a flat disk-shaped antenna body 110B connected to the outer waveguide of the coaxial waveguide 110A, and a plurality of the radial line slot antennas 110 shown in FIG. 1B formed in the opening of the antenna body 110B. And a radiation plate 110C formed with a plurality of slots 110b perpendicular to the slot 110a, and between the antenna body 110B and the radiation plate 110C, a slow phase composed of a dielectric plate having a constant thickness. A plate 110D is inserted.

  In the radial line slot antenna 110 having such a configuration, the microwave fed from the coaxial waveguide 110 travels between the disk-shaped antenna body 110B and the radiation plate 110C while spreading in the radial direction. At this time, the wavelength is compressed by the action of the retardation plate 110D. Thus, by forming the slots 110a and 110b concentrically and orthogonally to each other in accordance with the wavelength of the microwave traveling in the radial direction in this way, a plane wave having circular polarization can be obtained. Radiation can be performed in a direction substantially perpendicular to the radiation plate 110C.

  By using the radial line slot antenna 110, uniform high-density plasma is formed in the space 101B immediately below the shower plate 103. The high-density plasma thus formed has a low electron temperature, so that the substrate to be processed 114 is not damaged, and metal contamination due to sputtering of the vessel wall of the processing vessel 101 does not occur.

  In the plasma processing apparatus 100 of FIG. 1, the processing vessel 101 is formed in the processing vessel 101 between the shower plate 103 and the substrate to be processed 114 from an external processing gas source (not shown). A conductor structure 111 formed with a plurality of nozzles 113 for supplying a processing gas through the processing gas passage 112 is formed, and each of the nozzles 113 sends the supplied processing gas to the conductor structure 111. It is discharged into the space 101C between the substrate to be processed 114. That is, the conductor structure 111 functions as a processing gas supply unit. The conductor structure 111 constituting the processing gas supply unit efficiently passes the plasma formed in the space 101B between the adjacent nozzles 113 and 113 by diffusion from the space 101B to the space 101C. An opening having such a size as to be formed is formed.

  Therefore, when the processing gas is discharged from the processing gas supply unit 111 to the space 101C through the nozzle 113 in this way, the released processing gas is excited by the high-density plasma formed in the space 101B, and Uniform plasma treatment is performed on the substrate 114 to be processed efficiently and at high speed without damaging the substrate and the device structure on the substrate, and without contaminating the substrate. On the other hand, the microwave radiated from the radial line slot antenna 110 is blocked by the processing gas supply unit 111 made of a conductor, and does not damage the substrate 114 to be processed.

  Incidentally, in the plasma processing apparatus 100 described with reference to FIGS. 1A and 1B, it is very important that the processing gas is uniformly introduced from the processing gas supply unit 111. In addition, the processing gas supply unit 111 must be able to promptly pass the plasma excited in the space 101B to the space 101C immediately above the substrate to be processed 114.

  FIG. 2 is a bottom view showing a configuration of the processing gas supply unit 111 conventionally used.

  Referring to FIG. 2, the processing gas supply unit 111 is a disk-shaped plate member made of Al-containing stainless steel or the like, and a large number of large openings 111B through which high-density plasma in the space 101B passes are arranged in a matrix. Is formed. Further, a processing gas distribution passage 112A communicating with the processing gas passage 112 is formed in the disc-shaped plate member 111 along the outer periphery, and a lattice processing gas is connected to the processing gas distribution passage 112A. A passage 113A is formed, and a number of nozzle openings 113 are formed in the lattice-like processing gas passage 113A.

  According to such a configuration, the processing gas is introduced almost uniformly from the large number of nozzle openings 113 onto the surface of the substrate 114 to be processed, which is indicated by the broken lines in FIG.

  On the other hand, in the configuration of the bottom view of FIG. 2, the nozzle opening 113 is formed in a direction toward the substrate to be processed 114, so that even if the nozzle openings 113 are densely formed, the processing gas is supplied to the substrate to be processed. It is difficult to diffuse sufficiently until the surface of 114 is reached. If the nozzle openings 113 are formed too densely, the processing gas is mainly supplied to the periphery of the substrate 114 and may be depleted at the center. Further, in the plasma processing apparatus 100 of FIGS. 1A and 1B, the distance between the shower plate 103 and the substrate to be processed 114 is reduced so that the spaces 101B and 101C are quickly exhausted. The introduced processing gas quickly reaches the substrate to be processed 114 and cannot be sufficiently diffused.

  Further, in the plasma processing apparatus 100 of FIGS. 1A and 1B, the processing gas supply unit 111 is exposed to a large amount of heat flux due to high-density plasma, and thus has a problem that the temperature rises.

  Accordingly, it is a general object of the present invention to provide a novel and useful plasma processing apparatus that solves the above problems.

  A more specific problem of the present invention is to supply a plasma processing apparatus provided with a processing gas supply unit capable of supplying a processing gas uniformly.

  Another object of the present invention is to provide a plasma processing apparatus having a configuration capable of avoiding an increase in temperature of a processing gas supply unit.

Other problems of the present invention are as follows:
A processing vessel defined by an outer wall and provided with a holding table for holding a substrate to be processed;
An exhaust system coupled to the processing vessel ;
Before Symbol treatment on the container, set to face the target substrate vignetting, a microwave window made of a dielectric material,
A plasma gas supply unit that is provided between the substrate to be processed and the microwave window in the processing container, and supplies a plasma gas into the processing container;
A microwave antenna coupled to the microwave window;
Provided between the substrate to be processed with said plasma gas supplying part in the processing chamber, the processing chamber and a second space of the target substrate side to the first space of the plasma gas supply portion And a processing gas supply unit for defining ,
The processing gas supply unit includes a plurality of first openings communicating between the first space and the second space, and a portion that defines the first space and the second space. Prepared,
The portion defining the first space and the second space includes a processing gas passage connectable to a processing gas source, and communicates the processing gas to the second space. A plurality of second openings for discharging,
Plasma is generated in the first space using the microwave from the microwave antenna and the plasma gas, and the plasma is passed through the plurality of first openings toward the second space. Composed of
It is another object of the present invention to provide a plasma processing apparatus comprising a temperature control unit for cooling the surface temperature of the surface of the microwave window on the substrate to be processed to a predetermined temperature .

  According to the present invention, by controlling the temperature of the microwave window to about 150 ° C., the formation of deposits on the surface of the microwave window is suppressed.

  Other objects and features of the present invention will become apparent from the following detailed description of the preferred embodiment with reference to the drawings.

  According to the present invention, in the microwave plasma processing apparatus, it is possible to supply the processing gas uniformly into the processing container, and to perform uniform plasma processing.

[First Reference Example]
3A and 3B show a configuration of a microwave plasma processing apparatus 10 according to a first reference example of the present invention.

Referring to FIG. 3A, the microwave plasma processing apparatus 10 is provided in a processing container 11 and the processing container 11, and preferably a hot isostatic pressurization method (held by an electrostatic chuck). HIP) and a holding table 13 made of AlN or Al ₂ O _3, and in the processing container 11, the space 11 A surrounding the holding table 13 is equidistantly, that is, the object to be processed on the holding table 13. Exhaust ports 11a are formed in at least two locations, preferably three or more locations, in a substantially axisymmetric relationship with respect to the substrate 12. The processing vessel 11 is evacuated and decompressed by the unequal pitch unequal angle screw pump through the exhaust port 11a.

The processing vessel 11 is preferably made of austenitic stainless steel containing Al, and a protective film made of aluminum oxide is formed on the inner wall surface by oxidation treatment. Further, a disc-shaped shower plate having a large number of nozzle openings 14A made of dense Al ₂ O ₃ formed by the HIP method is formed on the outer wall of the processing container 11 corresponding to the substrate 12 to be processed. 14 is formed as part of the outer wall. The Al ₂ O ₃ shower plate 14 formed by the HIP method is formed using Y ₂ O ₃ as a sintering aid and has a porosity of 0.03% or less and substantially includes pores and pinholes. However, it has a very high thermal conductivity as a ceramic that reaches 30 W / m · K.

The shower plate 14 is mounted on the processing vessel 11 via a seal ring 11s, and a cover plate 15 made of a dense Al ₂ O ₃ formed by the same HIP process is further sealed on the shower plate 14. It is provided via a ring 11t. On the side of the shower plate 14 that is in contact with the cover plate 15, a recess 14 </ b> B that communicates with each of the nozzle openings 14 </ b> A and forms a plasma gas flow path is formed, and the recess 14 </ b> B is formed inside the shower plate 14. In addition, it communicates with another plasma gas flow path 14C communicating with the plasma gas inlet 11p formed on the outer wall of the processing vessel 11.

  The shower plate 14 is held by an overhanging portion 11b formed on the inner wall of the processing container 11, and the portion of the overhanging portion 11b that holds the shower plate 14 is rounded to suppress abnormal discharge. Is formed.

  Therefore, the plasma gas such as Ar or Kr supplied to the plasma gas inlet 11p sequentially passes through the flow paths 14C and 14B inside the shower plate 14, and then the space immediately below the shower plate 14 through the opening 14A. 11B is supplied uniformly.

On the cover plate 15, a disk-shaped slot plate 16 in which a large number of slots 16 a and 16 b shown in FIG. 3B are formed in close contact with the cover plate 15, and a disk-shaped antenna body 17 that holds the slot plate 16. And a slow phase plate 18 made of a low-loss dielectric material such as Al ₂ O ₃ , Si ₃ N ₄ , SiON, or SiO ₂ sandwiched between the slot plate 16 and the antenna body 17. A radial line slot antenna 20 is provided. The radial slot line antenna 20 is mounted on the processing vessel 11 via a seal ring 11u, and the radial line slot antenna 20 is connected to an external microwave source via a coaxial waveguide 21 having a rectangular or circular cross section. A microwave having a frequency of 2.45 GHz or 8.3 GHz is supplied from (not shown). The supplied microwave is radiated from the slots 16a and 16b on the slot plate 16 into the processing container 11 through the cover plate 15 and the shower plate 14, and the opening portion is formed in the space 11B immediately below the shower plate 14. Plasma is excited in the plasma gas supplied from 14A. At that time, the cover plate 15 and the shower plate 14 are made of Al ₂ O ₃ and function as an efficient microwave transmission window. At this time, in order to avoid excitation of plasma in the plasma gas flow paths 14A to 14C, the plasma gas is maintained at a pressure of about 6666 Pa to 13332 Pa (about 50 to 100 Torr) in the flow paths 14A to 14C. The

  In order to improve the adhesion between the radial line slot antenna 20 and the cover plate 15, in the microwave plasma processing apparatus 10 of this reference example, a ring is formed on a part of the upper surface of the processing container 11 engaged with the slot plate 16. A groove 11g is formed, and the groove 11g is exhausted through an exhaust port 11G communicating with the groove 11g, whereby the gap formed between the slot plate 16 and the cover plate 15 is decompressed, The radial line slot antenna 20 can be firmly pressed against the cover plate 15 by the atmospheric pressure. The gap includes slots 16a and 16b formed in the slot plate 16, but a gap may be formed for various reasons. The gap is sealed by a seal ring 11 u between the radial line slot antenna 20 and the processing container 11.

  Further, by filling the gap between the slot plate 16 and the cover plate 15 through the exhaust port 11G and the groove 15g with an inert gas having a low molecular weight, heat from the cover plate 15 to the slot plate 16 can be obtained. Can be promoted. As such an inert gas, it is preferable to use He having high thermal conductivity and high ionization energy. When filling the gap with He, it is preferable to set the pressure to about 0.8 atm. In the configuration of FIG. 3, a valve 11V is connected to the exhaust port 11G for exhausting the groove 15g and filling the groove 15g with inert gas.

  Out of the coaxial waveguide 21A, the outer waveguide 21A is connected to the disk-shaped antenna body 17, and the central conductor 21B is connected to the slot plate 16 through an opening formed in the slow wave plate 18. It is connected to the. Therefore, the microwave supplied to the coaxial waveguide 21A is radiated from the slots 16a and 16b while traveling in the radial direction between the antenna body 17 and the slot plate 16.

Figure 3 B shows the slots 16a, 16b formed on the slot plate 16.

Referring to FIG. 3 B, the slot 16a are arranged concentrically, in response to each of the slots 16a, slots 16b perpendicular is also formed concentrically thereto. The slots 16 a and 16 b are formed in the radial direction of the slot plate 16 at intervals corresponding to the wavelength of the microwave compressed by the slow phase plate 18, and as a result, the microwaves are substantially separated from the slot plate 16. Radiated as a plane wave. At this time, since the slots 16a and 16b are formed so as to be orthogonal to each other, the microwave radiated in this way forms a circularly polarized wave including two orthogonal polarization components.

Still referring to FIG. 3 A plasma treatment apparatus 10 of, on the antenna body 17, which is a cooling block 19 formed with a cooling water passage 19A is formed, the cooling block 19 with cooling water in the cooling water passage 19A By cooling, the heat accumulated in the shower plate 14 is absorbed through the radial line slot antenna 20. The cooling water passage 19A is formed in a spiral shape on the cooling block 19, and is preferably passed with cooling water that excludes dissolved oxygen by bubbling H ₂ gas and controls the oxidation-reduction potential.

Further, in the microwave plasma processing apparatus 10 of FIG. 3 A, in the processing vessel 11, between the substrate 12 to be processed on the shower plate 14 and the holder 13, provided on the outer wall of the processing vessel 11 A processing gas supply structure 31 having a grid-like processing gas passage through which a processing gas is supplied from the processing gas inlet 11r and discharged from a plurality of processing gas nozzle openings (see FIG. 5) is provided. And a desired uniform substrate processing is performed in a space 11C between the substrate 12 and the substrate 12 to be processed. Such substrate processing includes plasma oxidation processing, plasma nitriding processing, plasma oxynitriding processing, plasma CVD processing, and the like. In addition, a fluorocarbon gas such as C ₄ F ₈ , C ₅ F ₈ or C ₄ F ₆ that is easily dissociated, or an etching gas such as an F-based or Cl-based gas is supplied from the processing gas supply structure 31 to the space 11C. Reactive ion etching can be performed on the substrate 12 by applying a high frequency voltage from the high frequency power source 13 </ b> A to the holding table 13.

  In the microwave plasma processing apparatus 10 according to the present reference example, the outer wall of the processing container 11 is heated to a temperature of about 150 ° C., so that reaction byproducts and the like are prevented from adhering to the inner wall of the processing container. By performing dry cleaning about once, it is possible to operate stably and stably.

  FIG. 4 is a bottom view showing the configuration of the processing gas supply structure 31 in the configuration of FIG. 3A.

Referring to FIG. 4, the processing gas supply structure 31 is formed by stacking conductive disk members 31 ₁ and 31 ₂ such as Al alloy containing Mg or stainless steel added with Al, and allows plasma gas to pass therethrough. A matrix of openings 31A is formed. The opening 31A has a size of 19 mm × 19 mm, for example, and is repeatedly formed in the row direction and the column direction at a pitch of 24 mm, for example. The processing gas supply structure 31 as a whole has a thickness of about 8.5 mm, and is typically spaced from the surface of the substrate 12 to be processed by a distance of about 16 mm.

Figure 5 is a bottom view of a structure of a conductive disc member 31 ₁ in FIG. 4.

Referring to FIG. 5, the conductive disc member 31 lattice-like process gas passage 31B during _1, communicates with the process gas distribution passage 31C formed along the outer circumference of the disc member 31 ₁ indicated by a broken line in FIG. The processing gas distribution passage 31C is connected to the processing gas inlet 11r at a port 31c. Also on the lower surface of the disk 31 ₁ has a large number of process gas nozzle apertures 31D are formed to communicate with the processing gas passage 31B. Wherein from the nozzle opening 31D processing gas is released toward the conductive disc member 31 _2.

Figure 6 is a plan view showing the configuration of the conductive disc member 31 _2.

Referring to FIG 6, wherein the the conductive disc-like member 31 _second opening 31A corresponding to the opening portions 31A of the conductive disc member 31 in ₁ 'are formed in a matrix, wherein the openings 31A' It is defined by a lattice-like structure 31E of the conductive disc member 31 in _2.

As shown in FIG. 6, on the grid-like structure 31, the depth of the recess 31F of approximately 1mm is formed typically to correspond to each of the nozzle opening 31D of the conductive disc member 31 in ₁ The processing gas released from the nozzle opening 31D is prevented from going straight by the recess 31F, and is bent sideways in the flow path as shown in FIG. That is, it can be seen that the concave portion 31F forms a diffusion portion. However, FIG. 7 is a partially cut sectional view of the processing gas supply structure 31 of FIG. In FIG. 7, the same reference numerals are given to the parts described above, and the description thereof is omitted.

Figure 8 is an enlarged view showing a part of the conductive disc member 31 ₂ of FIG.

Referring to FIG. 8, recesses 31F _{1 to} 31F ₄ are formed around the opening 31A ′ as the diffusion part 31F. A pair of recesses, for example, recesses, facing each other with the opening 31A ′ therebetween. 31F ₁ and recess 31F ₂ , or recess 31F ₃ and recess 31F ₄ are formed alternately.

As a result, of the process gas stream which is bent to the side of the grid-shaped structure 31E of the concave portion 31F ₂ is formed by for example recesses 31F ₁ as shown in FIG. 9, the recess 31F ₂ is not formed portion 31E Hit ₂ and bend.

Similarly, the processing gas flow bent sideways by the recess 31F ₂ hits the portion 31E ₁ where the recess 31F ₁ is not formed in the lattice structure 31E where the recess 31F ₁ is formed, and is bent. . Further, the processing gas flow bent laterally by the concave portion 31F ₃ hits the portion 31E ₄ where the concave portion 31F ₄ is not formed in the lattice-like structure 31E in which the concave portion 31F ₄ is formed, and is bent. Also among the process gas stream which is bent to the side of the grid-shaped structure 31E of the concave portion 31F ₃ is formed by the recess 31F _4, strikes the portion 31E ₃ to the recess 31F ₃ is not formed, it is bent.

  As a result of complicated bending of the processing gas flow shown in FIG. 9, the processing gas flow is uniformly diffused and supplied to the space 11C.

  The lattice processing gas passages 31B and the processing gas nozzle openings 31D are provided so as to cover a region slightly larger than the substrate 12 to be processed, which is indicated by a broken line in FIG. By providing the processing gas supply structure 31 between the shower plate 14 and the substrate 12 to be processed, the processing gas can be plasma-excited and can be uniformly processed by the plasma-excited processing gas. .

  In the case where the processing gas supply structure 31 is formed of a conductor such as metal, the processing gas supply structure 31 is made of a microwave by setting the repetitive pitch of the lattice openings 31A shorter than the wavelength of the microwave. Form a short-circuit plane. In this case, microwave excitation of plasma occurs only in the space 11B, and in the space 11C including the surface of the substrate 12 to be processed, the processing gas is activated by the plasma diffused from the excitation space 11B.

  In the microwave plasma processing apparatus 10 according to this reference example, since the supply of the processing gas is uniformly controlled by using the processing gas supply structure 31, the problem of excessive dissociation of the processing gas on the surface of the substrate 12 to be processed is solved. Even when a structure having a large aspect ratio is formed on the surface of the substrate 12 to be processed, it is possible to perform a desired substrate processing to the back of the high aspect structure. That is, the microwave plasma processing apparatus 10 is effective for manufacturing a large number of generations of semiconductor devices having different design rules.

In the plasma processing apparatus 10 of the present reference example, the conductive disk members 31 ₁ and 31 ₂ can be formed of Mg-containing Al alloy or Al-added stainless steel. It is preferable to form a fluoride film. Further the conductive disk members 31 ₁ and 31 ₂ in the case of forming the Al addition stainless steel, idea to form a passivation film of aluminum oxide on the surface is desirable. In the plasma processing apparatus 10 according to the present invention, since the electron temperature in the excited plasma is low, the incident energy of the plasma is small, and the processing gas supply structure 31 is sputtered to cause metal contamination on the substrate 12 to be processed. Is avoided. The processing gas supply structure 31 can also be formed of ceramics such as alumina.

The only one of the conductive disk members 31 ₁ and 31 ₂ in the present embodiment the conductive, it is also possible to form the non-conductive member such as ceramic and the other.

[Second Reference Example]
FIG. 10 shows a configuration of a processing gas supply structure 41 according to the second reference example of the present invention. However, in FIG. 10, the same reference numerals are given to the parts described above, and description thereof is omitted.

Referring to FIG. 10, in the present embodiment the refrigerant passage 31e is formed in the lattice-like structure 31E in the conductive disc member 31 _2, as a result, excessive temperature increase suppression of the process gas supply structure 41 Is done.

In the structure of FIG. 10, L-shaped spacer members 31L _{1 to} 31L ₄ are formed on the lattice-like structure 31E, and the concave portions 31F _{1 to} 31F ₄ are defined by the spacer members 31L _{1 to} 31L _4. .

The structure of FIG. 10 can be easily created, and the manufacturing cost of the plasma processing apparatus can be reduced.

[Third Reference Example]
FIG. 11 shows the configuration of a plasma processing apparatus 10A according to a third reference example of the present invention. However, in FIG. 11, the same reference numerals are given to the parts described above, and the description thereof is omitted.

  Referring to FIG. 11, in the plasma processing apparatus 10 </ b> A, the shower plate 14 is removed, and instead, a plurality of plasma gas supply pipes 11 </ b> P are provided in the processing vessel 11, preferably symmetrically, in the gas passage 11 p. It is formed in communication. In the plasma processing apparatus 10A of the present reference example, the configuration is simplified, and the manufacturing cost can be greatly reduced.

Also in the plasma processing apparatus 10A having such a configuration, by using the processing gas supply structure 31 or 41 of FIG. 4, the uniform processing gas can be stably supplied to the space 11C on the substrate 12 to be processed. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Fourth Reference Example]
FIG. 12 shows a configuration of a plasma processing apparatus 10B according to a fourth reference example of the present invention. However, in FIG. 12, the parts described above are denoted by the same reference numerals, and description thereof is omitted.

Even in the plasma processing apparatus 10B having such a configuration, it is possible to stably supply a uniform processing gas to the space 11C on the target substrate 12 by using the processing gas supply structure 31 or 41 of FIG. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Fifth Reference Example]
FIG. 13 shows the configuration of a plasma processing apparatus 10C according to the fifth reference example of the present invention. However, in FIG. 13, the same reference numerals are given to the parts described above, and the description thereof is omitted.

  Referring to FIG. 13, in the plasma processing apparatus 10 </ b> C, the shower plate 14 is removed from the plasma processing apparatus 10 </ b> B of FIG. 12. Instead, a plurality of plasma gases are preferably disposed in the processing container 11, preferably symmetrically. A supply pipe 11P is formed in communication with the gas passage 11p. In the plasma processing apparatus 10 </ b> A of the present reference example, by forming a taper at the connection portion between the coaxial waveguide 21 and the radial line slot antenna 20, the reflection of microwaves due to the sudden impedance change is suppressed, and the shower plate 14. By providing the plasma gas supply pipe 11P instead of the structure, the configuration can be simplified and the manufacturing cost can be greatly reduced.

Also in the plasma processing apparatus 10C having such a configuration, by using the processing gas supply structure 31 or 41 of FIG. 4, the uniform processing gas can be stably supplied to the space 11C on the substrate 12 to be processed. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Sixth Reference Example]
FIG. 14 shows a configuration of a plasma processing apparatus 10D according to a fourth reference example of the present invention. However, in FIG. 14, the same reference numerals are given to the parts described above, and the description thereof is omitted.

  Referring to FIG. 14, in the plasma processing apparatus 10 </ b> B of the present reference example, in the plasma processing apparatus 10 having the configuration of FIGS. 3A and 3B, the connecting portion between the coaxial waveguide 21 and the radial line slot antenna 20 has a tapered portion. It is formed to reduce the sudden change in impedance and the associated microwave reflection at such a connection. For this purpose, a tapered portion 21b is formed at the tip of the central conductor 21B of the coaxial waveguide 21, and a tapered portion 21a is formed at the connecting portion between the outer waveguide 21A and the antenna body 17. .

  Referring to FIG. 14, in the plasma processing apparatus 10D of the present reference example, in the plasma processing apparatus 10B having the configuration of FIG. 12, the tip 21b of the central conductor 21B of the coaxial waveguide 21 is separated from the slot plate 16, The slow phase plate 18 is interposed therebetween. In this configuration, it is not necessary to screw the slot plate 16 to the tip end portion 21b of the central conductor 21B, and the surface of the slot plate 16 is surely flat. Therefore, in such a configuration, the radial line slot antenna 20 can be brought into close contact with the cover plate 15 with high accuracy, and the temperature of the shower plate 14 and the cover plate 15 can be effectively increased by cooling the antenna 20. It is possible to suppress it.

Even in the plasma processing apparatus 10D having such a configuration, it is possible to stably supply a uniform processing gas to the space 11C on the target substrate 12 by using the processing gas supply structure 31 or 41 of FIG. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Seventh Reference Example]
FIG. 15 shows the configuration of a plasma processing apparatus 10E according to the seventh reference example of the present invention. However, in FIG. 15, the same reference numerals are given to the parts described above, and the description thereof is omitted.

  Referring to FIG. 15, in the plasma processing apparatus 10 </ b> E, the shower plate 14 is removed from the plasma processing apparatus 10 </ b> D of FIG. 14. Instead, a plurality of plasma gases are preferably disposed in the processing container 11, preferably symmetrically. A supply pipe 11P is formed in communication with the gas passage 11p. As a result, the configuration of the plasma processing apparatus 10E is simplified as compared with the plasma processing apparatus 10D, and the manufacturing cost can be greatly reduced.

Also in the plasma processing apparatus 10E having such a configuration, by using the processing gas supply structure 31 or 41 of FIG. 4, the uniform processing gas can be stably supplied to the space 11C on the substrate 12 to be processed. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Eighth Reference Example]
FIG. 16 shows the configuration of a plasma processing apparatus 10F according to an eighth reference example of the present invention. However, in FIG. 16, the parts described above are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 16, in the plasma processing apparatus 10 </ b> F, the cover plate 15 of the previous plasma processing apparatus 10 </ b> E is removed, and the slot plate 16 of the radial line slot antenna 20 is exposed in the processing container 11.

  In the configuration of FIG. 16, the slot plate 16 is attached to the processing container 11 via a seal ring 11t, but the tip 21b of the center conductor 21B is formed behind the slow phase plate 18, There is no need to provide a seal ring that seals the tip 21b of the center conductor 21B against atmospheric pressure. In this reference example, since the slot plate 16 of the radial line slot antenna 20 is exposed inside the processing container 11, microwave loss does not occur, and efficient microwave excitation can be performed in the processing container 11. Become.

Even in the plasma processing apparatus 10F having such a configuration, it is possible to stably supply a uniform processing gas to the space 11C on the target substrate 12 by using the processing gas supply structure 31 or 41 of FIG. Become. In particular, by using the processing gas supply structure 41, it is possible to avoid an excessive temperature rise in the processing gas supply structure.

[Ninth Reference Example]
17A and 17B are a bottom view and a cross-sectional view, respectively, showing the configuration of the processing gas supply structure 51 according to the ninth reference example of the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 17A, in this reference example, the processing gas supply structure 51 is formed by a processing member gas supply passage and a spoke member 51B that extends in the radial direction, and is held by the spoke member 51B to form a processing gas passage. A concentric ring-shaped member 51A is formed, and a plurality of process gas supply nozzle openings 51C are formed on the bottom surface of the member 51A.

  Referring to FIG. 17B, in this reference example, the processing gas supply nozzle opening 51C is formed obliquely on the member 51A, and discharges the processing gas in an oblique direction with respect to the substrate 12 to be processed.

  By releasing the processing gas from the processing gas supply nozzle opening 51 </ b> C in an oblique direction with respect to the processing target substrate 12, the released processing gas rebounds on the processing target substrate 12, and a reaction byproduct is generated on the surface of the shower plate 103. The problem of forming deposits made of things etc. is avoided.

As shown in FIG. 17B, the member 51A has a configuration in which a cross section formed with a groove corresponding to the processing gas supply passage covers the surface of a U-shaped member 51a with a lid 51b, and the nozzle opening 51C. Can be formed by oblique machining of the member 51a.

[Example]
Next, examples of the present invention will be described.

  In this embodiment, the substrate processing apparatus 10 in FIG. 3A, the substrate processing apparatus 10A in FIG. 11, or the substrate processing apparatus 10B in FIG. 12 is used to suppress deposition of deposits such as reaction byproducts on the surface of the shower plate 103. In the substrate processing apparatus 10C of FIG. 13, the substrate processing apparatus 10D of FIG. 14, or the substrate processing apparatus 10E of FIG. 15, the substrate to be processed of the shower plate 13 or the cover plate 15 using the cooling block 19 as a temperature control device. 12 is controlled to about 150 ° C. through the radial line slot antenna 20. At that time, the processing gas supply mechanism shown in FIGS. 17A and 17B can be used.

  By controlling the temperature of the shower plate 13 or the cover plate 15 to 150 ° C. or more, the shower plate 13 or the cover can be obtained even when the CVD film forming process or the plasma etching process is performed in the processing space 11C. Adhesion of deposits to the surface of the plate 15 can be suppressed.

  On the other hand, when the temperature is substantially higher than 150 ° C., the processing gas supplied from the processing gas supply structures 31, 41, 51 may be decomposed. For this reason, it is preferable to control the temperature of the shower plate 13 or the cover plate 15 not to greatly exceed 150 ° C.

  Such temperature control can be performed by passing a medium such as Galden through the cooling water passage 19A of the cooling block 19.

  The present invention is not limited to the specific embodiments described above, and various modifications and changes can be made within the scope of the present invention.

  According to the present invention, in the microwave plasma processing apparatus, it is possible to supply the processing gas uniformly into the processing container, and to perform uniform plasma processing.

It is FIG. (1) which shows the structure of the microwave plasma processing apparatus using the conventional radial line slot antenna. It is FIG. (2) which shows the structure of the microwave plasma processing apparatus using the conventional radial line slot antenna. It is a bottom view which shows the process gas supply structure used with the plasma processing apparatus of FIG. It is FIG. (1) which shows the structure of the microwave plasma processing apparatus by the 1st reference example and Example of this invention. It is FIG. (2) which shows the structure of the microwave plasma processing apparatus by the 1st reference example and Example of this invention. It is a perspective view which shows the process gas supply structure used with the plasma processing apparatus of FIG. It is a bottom view which shows the electroconductive disk member which comprises a part of processing gas supply structure of FIG. It is a top view which shows the electroconductive disc member which comprises another part of the process gas supply structure of FIG. It is a figure explaining the effect | action of the process gas supply structure of FIG. It is a figure which expands and shows a part of electroconductive disc member of FIG. It is a figure explaining the effect | action of the electroconductive disc member of FIG. It is a figure which shows the structure of the process gas supply structure by the 2nd reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 3rd reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 4th reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 5th reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 6th reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 7th reference example of this invention. It is a figure which shows the structure of the plasma processing apparatus by the 8th reference example of this invention. It is FIG. (1) which shows a part of plasma processing apparatus by the 9th reference example of this invention. It is FIG. (2) which shows a part of plasma processing apparatus by the 9th reference example of this invention.

Explanation of symbols

10, 10A, 10B, 10C, 10D, 10E, 10F, 100 Plasma processing apparatus 11 Processing vessel 11a Exhaust port 11b Overhang part 11p Plasma gas supply port 11r Processing gas supply port 11A, 11B, 11C Space 11G Decompression and He supply port 11P Plasma gas inlet 12,114 Substrate 13 Holding base 13A High frequency power supply 14 Shower plate 14A Plasma gas nozzle opening 14B, 14C Plasma gas passage 15 Cover plate 16 Slot plate 16a, 16b Slot opening 17 Antenna body 18 Slow wave plate 18A , 18B Ring-shaped member 19 Cooling block 19A Cooling water passage 20 Radial line antenna 21 Coaxial waveguide 21A Outer waveguide 21B Inner feed line 21a, 21b Tapered surfaces 31, 41 51,111 process gas supply mechanism 31 _1, 31 ₂ conductive disc member 31A, 31A 'plasma diffusion path 31B, 113A process gas passages 31C, 112A process gas distribution passages 31c processing gas supply port 31D, 113 processing gas supply nozzle opening 31E grid-like member 31L ₁ ~31L ₄ L-shaped spacers 31e coolant passages 31F, 31F ₁ ~31F ₄ processing gas diffusing portion 51A concentrically ring-shaped member 51B spoke members 51a U-shaped member 51b lid

Claims (3)

A processing vessel defined by an outer wall and provided with a holding table for holding a substrate to be processed;
An exhaust system coupled to the processing vessel ;
Before Symbol treatment on the container, set to face the target substrate vignetting, a microwave window made of a dielectric material,
A plasma gas supply unit that is provided between the substrate to be processed and the microwave window in the processing container, and supplies a plasma gas into the processing container;
A microwave antenna coupled to the microwave window;
Provided between the substrate to be processed with said plasma gas supplying part in the processing chamber, the processing chamber and a second space of the target substrate side to the first space of the plasma gas supply portion And a processing gas supply unit for defining ,
The processing gas supply unit includes a plurality of first openings communicating between the first space and the second space, and a portion that defines the first space and the second space. Prepared,
The portion defining the first space and the second space includes a processing gas passage connectable to a processing gas source, and communicates the processing gas to the second space. A plurality of second openings for discharging,
Plasma is generated in the first space using the microwave from the microwave antenna and the plasma gas, and the plasma is passed through the plurality of first openings toward the second space. Composed of
The plasma processing apparatus further comprising a temperature control unit that cools a surface temperature of the surface of the microwave window on the substrate to be processed to a predetermined temperature . The plasma processing apparatus according to claim 1, wherein the temperature control unit is formed on the microwave antenna, and performs temperature control of the microwave window via the microwave antenna. The plasma processing apparatus according to claim 1, wherein the microwave window is a shower plate made of a dielectric plate on which the plasma gas supply unit is formed.

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