WO2013027470A1 - Plasma processor, microwave introduction device, and plasma processing method - Google Patents

Abstract

A microwave introduction device (5) has a microwave output unit (50) that generates microwaves and distributes and outputs the microwaves to a plurality of paths, an antenna unit (60) that introduces the microwaves output from the microwave output unit (50) into a process container (2), and a microwave radiation module (80) for radiating the microwaves introduced by the antenna unit (60) into the process container (2). The microwave radiation module (80) has a microwave-transmitting plate (81) as a dielectric window and a cover (82) as a conductor. The cover (82) controls the directions of the microwaves so that the microwaves introduced through the microwave-transmitting plate (81) into the process container (2) are directed toward a wafer (W).

Description

Plasma processing apparatus, microwave introducing apparatus, and plasma processing method

The present invention relates to a plasma processing apparatus, a microwave introducing apparatus, and a plasma processing method for guiding a microwave of a predetermined frequency to a processing container and generating plasma to plasma process an object to be processed.

2. Description of the Related Art As a plasma processing apparatus that performs a predetermined plasma process on an object to be processed such as a semiconductor wafer, a microwave plasma processing apparatus that generates plasma by introducing a microwave into a processing container is known. In this microwave plasma processing apparatus, it is possible to generate high-density plasma in a processing container, and for example, oxidation processing, nitriding processing, deposition processing, etching processing, and the like are performed by the generated plasma.

In the microwave plasma processing apparatus, a microwave introduction mechanism for introducing a microwave into the processing container is disposed on the upper part of the processing container. For example, in a microwave plasma processing apparatus of a slot antenna type in which microwaves are introduced into a processing container using a planar antenna having a plurality of slots, a microwave transmission window larger than the diameter of the object to be processed is usually provided on the ceiling of the processing container. The part is disposed to face the object to be processed. Further, for example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-259633), a plurality of microwave introduction mechanisms are provided on the upper part of the processing container in order to obtain a large plasma discharge in the processing container by applying a large amount of power. A microwave plasma processing apparatus has also been proposed.

However, in the conventional microwave plasma processing apparatus, there is almost no room for arranging other mechanisms other than the microwave introduction mechanism, such as a gas introduction mechanism, in the upper part of the processing vessel, and the degree of freedom in designing the apparatus is limited. There was a problem that it would end up.

The present invention provides a microwave plasma processing apparatus having a high degree of freedom in apparatus design, without providing a microwave introduction mechanism at the top of the processing vessel.

The plasma processing apparatus of the present invention comprises:
A processing container for storing an object to be processed;
A mounting section for mounting the object to be processed in the processing container;
A gas supply mechanism for supplying a processing gas into the processing container;
A microwave introduction device for generating a microwave for generating plasma of the processing gas in the processing container and for introducing the microwave into the processing container is provided.
In the plasma processing apparatus of the present invention, the microwave introduction device includes:
A dielectric window member disposed around the object to be processed and transmitting microwaves into the processing container;
A conductor member for regulating the microwave radiated into the processing container through the dielectric window member so as to be directed to the target object in a direction parallel to the surface of the target object;
A microwave radiation module.

In the plasma processing apparatus of the present invention, the microwave introduction device generates a microwave and outputs a microwave, and
It may further include one or a plurality of antenna modules that are attached to the lower part of the processing container from the outside and supply the microwaves output from the microwave output unit to the microwave radiation module.

In the plasma processing apparatus of the present invention, the dielectric window member may have a microwave radiation surface that is exposed to a space in the processing container and emits microwaves toward the object to be processed. The conductor member may cover the surface of the dielectric window member excluding the microwave radiation surface. In this case, the microwave radiation surface may have a shape corresponding to the shape of the edge of the object to be processed. For example, when the object to be processed is circular in plan view, the microwave radiation surface has an arc shape. It may have a curved shape.

The plasma processing apparatus of the present invention may have a plurality of the microwave radiation modules so as to surround the object to be processed. In this case, one or a plurality of the antenna modules may be connected to one microwave radiation module.

The plasma processing apparatus of the present invention may have at least three antenna modules.

In the plasma processing apparatus of the present invention, the lower end of the dielectric window member may be disposed at a height position equal to or higher than the height of the upper surface of the object to be processed placed on the placement portion.

In the plasma processing apparatus of the present invention, a gas introduction part for introducing a processing gas supplied from the gas supply mechanism may be provided in a ceiling part of the processing container. In this case, an exhaust port connected to an exhaust device for evacuating and exhausting the inside of the processing container may be provided in a ceiling portion of the processing container.

Further, in the plasma processing apparatus of the present invention, an exhaust port connected to an exhaust device for evacuating and exhausting the inside of the processing container may be provided in a side wall portion or a bottom wall portion of the processing container.

Further, in the plasma processing apparatus of the present invention, the placement section may be provided on the bottom wall portion of the processing container.

Moreover, the plasma processing apparatus of the present invention may have a high frequency power supply unit that supplies high frequency power to the mounting unit.

Further, the plasma processing apparatus of the present invention may have a DC voltage application unit to which a DC voltage is applied between the mounting unit and the microwave radiation module.

The plasma processing method of the present invention is to process an object to be processed by any of the above plasma processing apparatuses.

The microwave introducing apparatus of the present invention generates a microwave for generating plasma of a processing gas in a processing container that accommodates an object to be processed, and introduces the microwave into the processing container. It is.
This microwave introduction device
A dielectric window member disposed around the object to be processed and transmitting microwaves into the processing container;
A conductor member for regulating the microwave radiated into the processing container through the dielectric window member so as to be directed to the target object in a direction parallel to the surface of the target object;
A microwave radiation module may be included.

The microwave introducing device of the present invention is
A microwave output unit for generating and outputting a microwave;
One or a plurality of antenna modules that are attached to the lower part of the processing container from the outside and that supply the microwaves output from the microwave output unit to the microwave radiation module;
May be further provided.

It is sectional drawing which shows the structure of the outline of the plasma processing apparatus which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the structure of the control part shown in FIG. It is explanatory drawing which shows the structure of the microwave output part and antenna unit in the microwave introduction apparatus shown in FIG. It is principal part sectional drawing which expands and shows the microwave introduction part and microwave radiation module in the microwave introduction apparatus shown in FIG. It is a top view which shows the planar antenna of a microwave introduction part. It is a top view which shows arrangement | positioning of the microwave radiation module shown in FIG. It is a principal part perspective view explaining arrangement | positioning of one microwave radiation module and a wafer. It is explanatory drawing which shows the 1st modification of the plasma processing apparatus which concerns on 1st Embodiment. It is explanatory drawing which shows the 2nd modification of the plasma processing apparatus which concerns on 1st Embodiment. It is a bottom view of the ceiling part in the plasma processing apparatus of FIG. It is sectional drawing which shows typically the structure of the plasma processing apparatus of a comparative example. It is explanatory drawing which shows the 3rd modification of the plasma processing apparatus which concerns on 1st Embodiment. It is explanatory drawing which shows the 4th modification of the plasma processing apparatus which concerns on 1st Embodiment. It is explanatory drawing which shows the 5th modification of the plasma processing apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the outline of the plasma processing apparatus which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the structure of the microwave output part and antenna module in the microwave introduction apparatus shown in FIG. It is sectional drawing which shows the structure of the outline of the plasma processing apparatus which concerns on the 3rd Embodiment of this invention. It is sectional drawing which expands and shows the principal part of the plasma processing apparatus shown in FIG. It is sectional drawing which shows the schematic structure of the plasma processing apparatus which concerns on the 4th Embodiment of this invention.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a schematic configuration of the plasma processing apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a schematic configuration of the plasma processing apparatus according to the present embodiment. FIG. 2 is an explanatory diagram illustrating a configuration of the control unit illustrated in FIG. 1. The plasma processing apparatus 1 according to the present embodiment performs film formation processing and diffusion on a semiconductor wafer (hereinafter, simply referred to as “wafer”) W for manufacturing a semiconductor device, for example, with a plurality of continuous operations. It is an apparatus that performs predetermined processing such as processing, etching processing, and ashing processing.

The plasma processing apparatus 1 includes a processing container 2 that accommodates a wafer W that is an object to be processed, a placement unit 17 that places the wafer W inside the processing container 2, and a gas supply that supplies gas into the processing container 2. A mechanism 3, an exhaust device 4 for evacuating the inside of the processing container 2, and a microwave introducing device 5 for generating a microwave for generating plasma in the processing container 2 and introducing a microwave into the processing container 2. And a control unit 8 that controls each component of the plasma processing apparatus 1. As a means for supplying the gas into the processing container 2, an external gas supply mechanism that is not included in the configuration of the plasma processing apparatus 1 may be used instead of the gas supply mechanism 3.

The processing container 2 has a substantially cylindrical shape, for example. The processing container 2 is made of a metal material such as aluminum and an alloy thereof. The surface of the processing container 2 may be subjected to, for example, alumite treatment (anodizing treatment). The processing container 2 is grounded. Note that a sealing member is provided at a joint portion between the processing container 2 and each member attached to the processing container 2, and the airtightness in the processing container 2 is maintained.

The processing container 2 has a plate-like ceiling portion 11 and a bottom wall portion 13, and a side wall portion 12 that connects the ceiling portion 11 and the bottom wall portion 13. The ceiling part 11 has a plurality of openings. For example, the ceiling portion 11 is provided with a plurality of exhaust ports 11a. The ceiling portion 11 is provided with a plurality of gas introduction openings 11b. A nozzle 16 described later is attached to each gas introduction opening 11b.

The side wall portion 12 has a loading / unloading port 12 a for loading / unloading the wafer W to / from a transfer chamber (not shown) adjacent to the processing container 2. A gate valve G is disposed between the processing container 2 and a transfer chamber (not shown). The gate valve G has a function of opening and closing the loading / unloading port 12a. The gate valve G hermetically seals the processing container 2 in the closed state, and enables the transfer of the wafer W between the processing container 2 and a transfer chamber (not shown) in the open state.

A mounting portion 17 is provided on the bottom wall portion 13. The placement portion 17 is formed with a thickness slightly larger than that of the bottom wall portion 13 by a member different from the bottom wall portion 13, and is fixed to the bottom wall portion 13. The mounting portion 17 can be formed of, for example, a metal material such as aluminum and its alloy, ceramics, and the like, similar to the processing container 2. The placement unit 17 is provided with a placement region 17a. This placement area 17a is for placing the wafer W, which is the object to be processed, horizontally. In the plasma processing apparatus 1 of the present embodiment, the placement region 17 a is a recess formed on the inner wall surface of the placement portion 17 slightly larger than the size of the wafer W. The placement region 17a is not limited to the concave portion, and may be provided in a convex portion or a table shape. Further, an electrode 26 is embedded in the mounting portion 17 in the vicinity of the mounting region 17a and immediately below it. The electrode 26 has the same size as the placement region 17 a and is entirely covered with an insulating coating material 27.

The bottom wall portion 13 has a plurality of openings 13b (only two are shown in FIG. 1). A microwave introducing portion 63 (a part of the antenna module 61) of the microwave introducing device 5 described later is attached to each opening 13b from the outside of the processing container 2. That is, the microwave introduction device 5 is provided in the lower part of the processing container 2. The microwave introduction device 5 functions as a plasma generation unit that introduces an electromagnetic wave (microwave) into the processing container 2 to generate plasma. The configuration of the microwave introduction device 5 will be described in detail later.

The plasma processing apparatus 1 further includes a high-frequency bias power source 25 that supplies high-frequency power to the mounting unit 17 including the mounting region 17a, and a matching unit 24 provided between the mounting unit 17 and the high-frequency bias power source 25. It has. The high-frequency bias power source 25 is electrically connected to an electrode 26 embedded immediately below the placement region 17 a of the placement unit 17. The high frequency bias power supply 25 supplies high frequency power to the mounting unit 17 in order to attract ions to the wafer W. When the mounting portion 17 is formed of a conductive material, the electrode 26 is not provided, and an insulating material is interposed between the mounting portion 17 and the bottom wall portion 13, so that the mounting portion 17 and the high frequency bias power source are provided. 25 may be electrically connected to each other. Further, it is possible to adopt an apparatus configuration that does not use the high-frequency bias power supply 25 and the matching unit 24. In this case, the mounting portion 17 may be formed integrally with the bottom wall portion 13.

Although not shown, the plasma processing apparatus 1 further includes a temperature control mechanism that heats or cools the placement region 17a. For example, the temperature control mechanism controls the temperature of the wafer W within a range of 25 ° C. (room temperature) to 900 ° C. The mounting region 17a is provided with a plurality of support pins 28 provided so as to be able to project and retract with respect to the upper surface (mounting surface) thereof. The plurality of support pins 28 are configured to be displaced up and down by an arbitrary lifting mechanism so that the wafer W can be transferred to and from a transfer chamber (not shown) at the raised position.

The plasma processing apparatus 1 further includes a gas introduction part 15 provided in the ceiling part 11 of the processing container 2. The gas introduction part 15 has a nozzle 16 having a cylindrical shape that is attached to a plurality of gas introduction openings 11 b of the ceiling part 11. The nozzle 16 has a gas hole 16a formed on the lower surface thereof. The arrangement of the nozzles 16 will be described later.

The gas supply mechanism 3 includes a gas supply device 3 a including a gas supply source 31, and a pipe 32 that connects the gas supply source 31 and the gas introduction unit 15. In FIG. 1, one gas supply source 31 is illustrated, but the gas supply device 3 a may include a plurality of gas supply sources according to the type of gas used.

The gas supply source 31 is used as a gas supply source of, for example, a rare gas for plasma generation or a processing gas used for oxidation treatment, nitridation treatment, film formation treatment, etching treatment, and ashing treatment. For example, Ar, Kr, Xe, He, or the like is used as a rare gas for generating plasma. As the processing gas used for the oxidation treatment, for example, an oxidizing gas such as oxygen gas, ozone, or NO ₂ gas is used. Nitriding gas, NH ₃ gas, N ₂ O gas, or the like is used as a processing gas used for the nitriding treatment. When the CVD process is performed in the processing container 2, the gas supply source 31 is used to clean the inside of the processing container 2, the film forming raw material gas, the purge gas used when replacing the atmosphere in the processing container 2, and the inside of the processing container 2. It is used as a supply source for cleaning gas and the like used in the process. For example, TiCl ₄ gas and NH ₃ gas are used as the film forming source gas. As the purge gas, for example, N ₂ , Ar, or the like is used. For example, ClF ₃ , NF ₃ or the like is used as the cleaning gas. As the etching gas, CF ₄ gas, HBr gas, or the like is used. As the ashing gas, oxygen gas or the like is used.

Although not shown, the gas supply device 3a further includes a mass flow controller and an opening / closing valve provided in the middle of the pipe 32. The types of gases supplied into the processing container 2 and the flow rates of these gases are controlled by a mass flow controller and an opening / closing valve.

The plasma processing apparatus 1 further includes an exhaust pipe 14 that connects the exhaust port 11 a and the exhaust apparatus 4. The exhaust device 4 includes, for example, an APC valve and a high-speed vacuum pump that can depressurize the internal space of the processing container 2 to a predetermined vacuum level at high speed. Examples of such a high-speed vacuum pump include a turbo molecular pump. By operating the high-speed vacuum pump of the exhaust device 4, the internal space of the processing container 2 is depressurized to a predetermined degree of vacuum, for example, 0.133 Pa. In FIG. 1, a plurality of exhaust ports 11a are connected to one exhaust device 4 via the exhaust pipe 14, but the exhaust devices 4 may be provided individually for each exhaust port 11a.

Each component of the plasma processing apparatus 1 is connected to the control unit 8 and controlled by the control unit 8. The control unit 8 is typically a computer. In the example illustrated in FIG. 2, the control unit 8 includes a process controller 91 including a CPU, and a user interface 92 and a storage unit 93 connected to the process controller 91.

In the plasma processing apparatus 1, the process controller 91 includes each component (for example, the high frequency bias power supply 25, the gas supply device, etc.) related to process conditions such as temperature, pressure, gas flow rate, high frequency power for bias application, and microwave output. 3a, the exhaust device 4, the microwave introduction device 5 and the like).

The user interface 92 has a keyboard and a touch panel on which a process manager manages command input to manage the plasma processing apparatus 1, a display that visualizes and displays the operating status of the plasma processing apparatus 1, and the like.

The storage unit 93 stores a control program (software) for realizing various processes executed by the plasma processing apparatus 1 under the control of the process controller 91, a recipe in which processing condition data, and the like are recorded. . The process controller 91 calls and executes an arbitrary control program or recipe from the storage unit 93 as necessary, such as an instruction from the user interface 92. Thus, desired processing is performed in the processing container 2 of the plasma processing apparatus 1 under the control of the process controller 91.

The control program and recipe described above can be stored in a computer-readable storage medium such as a CD-ROM, hard disk, flexible disk, flash memory, DVD, or Blu-ray disk. Also, the above recipe can be transmitted from other devices as needed via, for example, a dedicated line and used online.

Next, the configuration of the microwave introduction device 5 will be described in detail with reference to FIGS. 1 and 3 to 7. FIG. 3 is an explanatory diagram showing configurations of the microwave output unit 50 and the antenna unit 60 in the microwave introduction device 5. FIG. 4 is an enlarged cross-sectional view showing the microwave introduction part 63 and the microwave radiation module 80 attached to the processing container 2. FIG. 5 is a plan view showing the planar antenna 71 in the microwave introduction unit 63 shown in FIG. FIG. 6 is a plan view for explaining the arrangement of the microwave radiation module 80 in the processing container 2. FIG. 7 is a main part perspective view for explaining the arrangement of one microwave radiation module 80 and the wafer W. FIG.

As described above, the microwave introduction device 5 is provided at the lower portion of the processing container 2 and functions as a plasma generating means for introducing an electromagnetic wave (microwave) into the processing container 2 to generate plasma. As shown in FIG. 1 and FIG. 3, the microwave introduction device 5 generates a microwave, distributes the microwave to a plurality of paths, and outputs the microwave, and the microwave output unit 50 An antenna unit 60 for introducing the output microwave into the processing container 2 and a microwave radiation module 80 for radiating the microwave introduced by the antenna unit 60 into the processing container 2 are provided.

<Microwave output section>
The microwave output unit 50 distributes the microwave amplified by the power supply unit 51, the microwave oscillator 52, the amplifier 53 that amplifies the microwave oscillated by the microwave oscillator 52, and the microwave amplified by the amplifier 53 to a plurality of paths. And a distributor 54. The microwave oscillator 52 oscillates microwaves (for example, PLL oscillation) at a predetermined frequency (for example, 2.45 GHz). Note that the frequency of the microwave is not limited to 2.45 GHz, and may be 8.35 GHz, 5.8 GHz, 1.98 GHz, or the like. Moreover, such a microwave output part 50 can be applied also when the frequency of a microwave is made into the range of 800 MHz to 1 GHz, for example. The distributor 54 distributes the microwave while matching the impedances of the input side and the output side.

<Antenna unit>
The antenna unit 60 includes a plurality of antenna modules 61. Each of the plurality of antenna modules 61 introduces the microwave distributed by the distributor 54 into the processing container 2. Each antenna module 61 has an amplifier unit 62 that mainly amplifies and outputs the distributed microwave, and a microwave introduction unit 63 that introduces the microwave output from the amplifier unit 62 into the processing container 2. is doing.

(Amplifier part)
The amplifier unit 62 includes a phase shifter 62A that changes the phase of the microwave, a variable gain amplifier 62B that adjusts the power level of the microwave input to the main amplifier 62C, a main amplifier 62C configured as a solid state amplifier, It includes an isolator 62D that separates reflected microwaves that are reflected by an antenna unit of a microwave introducing unit 63, which will be described later, and that travel toward the main amplifier 62C.

The phase shifter 62A is configured to change the microwave radiation characteristic by changing the phase of the microwave. The phase shifter 62A is used to change the plasma distribution by controlling the directivity of the microwave by adjusting the phase of the microwave for each antenna module 61, for example. If such adjustment of the radiation characteristics is not performed, the phase shifter 62A may not be provided.

The variable gain amplifier 62B is used for adjusting variations of individual antenna modules 61 and adjusting plasma intensity. For example, by changing the variable gain amplifier 62B for each antenna module 61, the plasma distribution in the entire processing container 2 can be adjusted.

Although not shown, the main amplifier 62C includes, for example, an input matching circuit, a semiconductor amplifying element, an output matching circuit, and a high Q resonance circuit. As the semiconductor amplifying element, for example, GaAs HEMT, GaN HEMT, and LD (Laterally Diffused) -MOS capable of class E operation are used.

The isolator 62D has a circulator and a dummy load (coaxial terminator). The circulator guides the reflected microwave reflected by the antenna section of the microwave introduction section 63 described later to the dummy load. The dummy load converts the reflected microwave guided by the circulator into heat.

(Microwave introduction part)
As shown in FIG. 1, the plurality of microwave introduction portions 63 are attached to the opening 13 b provided in the bottom wall portion 13 of the processing container 2. More specifically, the upper part of the microwave introduction part 63 is inserted into the opening part 13b and fixed by a fixing means (not shown). As shown in FIG. 4, the microwave introduction unit 63 includes a tuner 64 that matches impedance, an antenna unit 65 that radiates the amplified microwave into the processing container 2, and a metal material. A main body container 66 having a cylindrical shape extending in the direction, and an inner conductor 67 extending in the same direction as the main container container 66 extends in the main body container 66. The main body container 66 and the inner conductor 67 constitute a coaxial tube. The main body container 66 constitutes the outer conductor of this coaxial tube. The inner conductor 67 has a rod shape or a cylindrical shape. A space between the inner peripheral surface of the main body container 66 and the outer peripheral surface of the inner conductor 67 forms a microwave transmission path 68.

Although not shown, the antenna module 61 further includes a power feeding conversion unit provided on the base end side (lower end side) of the main body container 66. The power feeding conversion unit is connected to the main amplifier 62C via a coaxial cable. The isolator 62D is provided in the middle of the coaxial cable.

The tuner 64 constitutes a slag tuner. Specifically, as shown in FIG. 4, the tuner 64 includes two slugs 74 </ b> A and 74 </ b> B disposed on the base end side (lower end side) of the antenna body 65 of the main body container 66, and 2 An actuator 75 for operating the two slugs 74A and 74B and a tuner controller 76 for controlling the actuator 75 are provided.

The slugs 74 </ b> A and 74 </ b> B have a plate shape and an annular shape, and are disposed between the inner peripheral surface of the main body container 66 and the outer peripheral surface of the inner conductor 67. The slugs 74A and 74B are made of a dielectric material. As a dielectric material for forming the slags 74A and 74B, for example, high-purity alumina having a relative dielectric constant of 10 can be used. High-purity alumina usually has a relative dielectric constant larger than that of quartz (relative dielectric constant 3.88) or Teflon (registered trademark) (relative dielectric constant 2.03), which is used as a material for forming slag. The thickness of 74A, 74B can be made small. Further, high-purity alumina has a feature that the dielectric loss tangent (tan δ) is smaller than that of quartz or Teflon (registered trademark), and the loss of microwaves can be reduced. High-purity alumina further has a feature of low distortion and a feature of being resistant to heat. The high-purity alumina is preferably an alumina sintered body having a purity of 99.9% or more. Further, single crystal alumina (sapphire) may be used as high purity alumina.

The tuner 64 moves the slugs 74A and 74B in the vertical direction by the actuator 75 based on a command from the tuner controller 76. Thereby, the tuner 64 adjusts the impedance. For example, the tuner controller 76 adjusts the positions of the slugs 74A and 74B so that the terminal impedance is 50Ω.

In the present embodiment, the main amplifier 62C of the amplifier unit 62, the tuner 64 of the microwave introduction unit 63, and the planar antenna 71 are arranged close to each other. In particular, the tuner 64 and the planar antenna 71 constitute a lumped constant circuit and function as a resonator. There is an impedance mismatch in the mounting portion of the planar antenna 71. In the present embodiment, the tuner 64 can be tuned with high accuracy including plasma, and the influence of reflection on the planar antenna 71 can be eliminated. Further, the tuner 64 can eliminate impedance mismatch up to the planar antenna 71 with high accuracy, and can substantially make the mismatched portion a plasma space. Thereby, the tuner 64 enables high-precision plasma control.

The antenna unit 65 is provided on the opposite side of the main body container 66 from the power conversion unit. As described above, the portion of the main body container 66 closer to the base end than the antenna portion 65 has an impedance adjustment range by the tuner 64.

As shown in FIG. 4, the antenna unit 65 includes a planar antenna 71 connected to the upper end portion of the inner conductor 67 and a microwave slow wave material 72 disposed on the lower surface side of the planar antenna 71. .

The planar antenna 71 has a disc shape. The planar antenna 71 has a slot 71 a formed so as to penetrate the planar antenna 71. In the example shown in FIG. 5, four slots 71a are provided, and each slot 71a has a circular arc shape of an equal size. The number of slots 71a is not limited to four, but may be five or more, or may be one or more and three or less.

The microwave slow wave material 72 is formed of a material having a dielectric constant larger than that of a vacuum. As a material for forming the microwave slow wave material 72, for example, fluororesin such as quartz, ceramics, polytetrafluoroethylene resin, polyimide resin, or the like can be used. Microwaves have a longer wavelength in vacuum. The microwave slow wave material 72 has a function of adjusting the plasma by shortening the wavelength of the microwave. Further, the phase of the microwave varies depending on the thickness of the microwave slow wave material 72. Therefore, by adjusting the phase of the microwave according to the thickness of the microwave slow wave material 72, the planar antenna 71 can be adjusted to be at the antinode position of the standing wave. Thereby, while being able to suppress the reflected wave in the planar antenna 71, the radiation energy of the microwave radiated | emitted from the planar antenna 71 can be enlarged. In other words, this allows microwave power to be efficiently introduced into the processing container 2.

<Microwave radiation module>
As shown in FIGS. 1 and 4, the microwave radiation module 80 includes a microwave transmission plate 81 as a dielectric window member and a cover member 82 as a conductor member. The microwave radiation module 80 is disposed inside the processing container 2. The lower end of the microwave radiation module 80 (that is, the lower surface of the microwave transmission plate 81) is provided so as to be substantially in contact with the upper surface of the planar antenna 71. Thereby, one microwave radiation module 80 is connected to one antenna module 61 and radiates the microwave introduced through the antenna module 61 toward the space in the processing container 2.

As shown in FIG. 6, in the plasma processing apparatus 1 of the present embodiment, around the wafer W in the processing container 2, four microwave radiation modules 80 (in FIG. 6, reference numerals 80A1, 80A2, 80A3, and 80A4). Express). The microwave radiation modules 80A1, 80A2, 80A3, and 80A4 are separated from each other and are equally arranged on the same circumference so as to surround the periphery of the wafer W. In the present embodiment, the four microwave radiation modules 80A1, 80A2, 80A3 and 80A4 have the same configuration. In FIG. 6, the position of the planar antenna 71 of the antenna module 61 connected to each of the microwave radiation modules 80A1, 80A2, 80A3, and 80A4 is indicated by a broken line, and the processing container 2 is not shown.

(Microwave transmission plate)
The microwave transmission plate 81 is disposed around the wafer W so as to surround the wafer W, and transmits the microwave introduced by the antenna module 61 and radiates it into the processing container 2. The microwave transmission plate 81 is made of a dielectric material. For example, quartz or ceramics is used as a dielectric material for forming the microwave transmission plate 81. In the plasma processing apparatus 1 of the present embodiment, the microwave transmission plate 81 is fixed to the bottom wall portion 13 of the processing container 2 by a cover member 82.

(Cover member)
The cover member 82 regulates the direction of the microwave so that the microwave introduced into the processing container 2 through the microwave transmission plate 81 is directed to the wafer W along a plane parallel to the surface of the wafer W. . That is, the cover member 82 is a member that determines the direction of the microwave that is transmitted through the microwave transmission plate 81 and introduced into the space in the processing container 2. The cover member 82 is formed of a metal material such as aluminum and an alloy thereof. The surface of the cover member 82 may be subjected to, for example, alumite treatment (anodization treatment). Further, a film such as silicon or Y ₂ O ₃ may be formed. The cover member 82 is provided in close contact with the microwave transmission plate 81 so as to cover the microwave transmission plate 81. The cover member 82 is fixed to the bottom wall portion 13 of the processing container 2 by an arbitrary fixing means such as a screw.

In the example shown in FIGS. 4, 6 and 7, the microwave transmission plate 81 has a rectangular shape with a fan shape in plan view, and has a three-dimensional shape whose longitudinal section has a constant thickness. The cover member 82 also has a fan shape in plan view corresponding to the microwave transmitting plate 81, and its longitudinal section in the short direction is L-shaped. The shapes of the microwave transmission plate 81 and the cover member 82 are not limited to those shown in the drawings, and can be any shape according to the shape of the object to be processed.

As shown in FIGS. 4 and 7, the side surface on one side (inner peripheral side) of the microwave transmission plate 81 is not covered with the cover member 82 and is exposed to the internal space of the processing container 2. The exposed surface of the microwave transmission plate 81 is a microwave radiation surface 81 a that radiates microwaves toward the wafer W placed on the placement region 17 a in the processing container 2. In FIG. 4, the direction of the microwave in the surface wave mode radiated from the microwave radiation surface 81a is indicated by a thick arrow.

In the plasma processing apparatus 1 of the present embodiment, the microwave radiation surface 81a has a shape corresponding to the edge shape of the wafer W that is circular in plan view. That is, the microwave radiation surface 81 a is curved in an arc shape and has a curved surface corresponding to the edge shape of the wafer W. Thus, by making the shape of the microwave radiation surface 81a correspond to the edge shape of the wafer W, the microwaves are efficiently directed from the microwave radiation surfaces 81a of the four microwave transmission plates 81 toward the center O of the wafer W. Can radiate.

As shown in FIG. 4, it is preferable that the lower end of the microwave transmission plate 81 is disposed at a height position equal to or higher than the height of the upper surface of the wafer W placed on the placement region 17a. In particular, it is more preferable that the lower surface of the microwave transmission plate 81 coincides with a virtual plane obtained by enlarging the upper surface of the wafer W placed on the placement region 17a. In the plasma processing apparatus 1 of the present embodiment, the upper surface of the wafer W, the inner surface S around the wafer W in the surface of the mounting portion 17 and the bottom wall portion 13, and the lower surface of the microwave transmission plate 81 are substantially the same. They are the same height and are formed on the same virtual plane. By arranging the microwave transmission plate 81 at such a height, boundary conditions such as a step can be eliminated between the microwave radiation surface 81 a of the microwave transmission plate 81 and the wafer W. Accordingly, it is possible to efficiently guide the surface-wave mode microwave radiated from the microwave radiation surface 81 a toward the surface of the wafer W and generate plasma above the wafer W.

Further, as shown in FIG. 1, the plasma processing apparatus 1 according to the present embodiment is configured such that high-frequency power can be supplied from the high-frequency bias power source 25 to the placement unit 17 including the placement region 17a. By applying high frequency power from the high frequency bias power supply 25 to the mounting portion 17, ions can be drawn into the wafer W, so that, for example, when the plasma processing apparatus 1 performs processing with strongly ionic plasma, the processing efficiency is improved. Can be improved.

In the plasma processing apparatus 1 of the present embodiment, the microwave radiated from the microwave radiation surface 81a of the microwave transmission plate 81 is exposed between the microwave transmission plate 81 and the wafer W as shown in FIG. It propagates in the surface wave mode on the metal surface (the inner surface S around the wafer W in the bottom wall portion 13). Thus, the surface wave propagating on the metal surface is guided by a sheath (not shown) existing between the plasma and the metal surface. That is, the surface wave propagates between the low electron density layer having a low dielectric constant present in the sheath and the plasma. For this reason, it is preferable to form a sprayed film made of a material such as silicon on at least the inner surface S around the wafer W in the bottom wall portion 13. The sprayed film can prevent the inner surface S from being scraped by microwaves and causing contamination. Instead of the sprayed film, for example, a silicon annular member may be disposed on the inner surface S exposed between the microwave transmitting plate 81 and the wafer W to cover the inner surface S.

In the microwave introducing device 5 configured as described above, the microwave amplified by the main amplifier 62C passes between the inner peripheral surface of the main body container 66 and the outer peripheral surface of the inner conductor 67 (microwave transmission path 68). It passes through the planar antenna 71, passes through the microwave transmission plate 81 from the slot 71 a of the planar antenna 71, and is radiated to the internal space of the processing container 2. At this time, since the radiation direction of the microwave is regulated by the cover member 82, the microwave is radiated from the microwave radiation surface 81 a facing the space in the processing chamber 2 toward the wafer W. This microwave propagates in the direction of the wafer W as a surface wave on the inner surface S around the wafer W in the bottom wall portion 13. In the plasma processing apparatus 1 of the present embodiment, the microwave radiation surface 81a has a curved surface corresponding to the edge shape of the wafer W that is circular in plan view, so that the microwave in the surface wave mode is directed to the center O of the wafer W. It is radiated efficiently toward. In FIG. 6, the direction of the microwave radiated | emitted from microwave radiation module 80A1 typically was shown with the thick arrow. Note that the surface wave mode microwaves radiated from the microwave radiation modules 80A1, 80A2, 80A3, and 80A4 can be controlled in phase by the phase shifter 62A of the amplifier unit 62 to control mutual interference. it can. A surface wave plasma is generated immediately above the wafer W by the microwaves thus radiated, and a predetermined plasma process is performed on the wafer W.

(First modification)
FIG. 8 is an explanatory diagram showing a first modification of the microwave introduction device 5 in the plasma processing apparatus 1 of the first embodiment. FIG. 8 shows the arrangement of the microwave radiation module 80 and the wafer W in the processing container 2 as in FIG. In FIG. 8, two antenna modules 61 are connected to one microwave radiation module 80. That is, in this modification, four microwave radiation modules 80 (represented by reference numerals 80B1, 80B2, 80B3, and 80B4 in FIG. 8) are provided around the wafer W so as to surround the wafer W. Two antenna modules 61 are connected to each. In FIG. 8, the position of the planar antenna 71 of the antenna module 61 is indicated by a broken line. Thus, by connecting two or more antenna modules 61 to one microwave radiation module 80, the controllability of the density of the plasma generated in the processing container 2 can be improved.

Note that the number of antenna modules 61 connected to one microwave radiation module 80 may be three or more. Further, in FIG. 8, an equal number of antenna modules 61 are connected to the four microwave radiation modules 80 (80B1 to 80B4), but a different number of antenna modules 61 are connected to each microwave radiation module 80. You can also

(Second modification)
Moreover, FIG. 9 is explanatory drawing which shows the 2nd modification of the microwave introduction apparatus 5 in the plasma processing apparatus 1 of 1st Embodiment. 6 and 8 show an example in which four microwave radiation modules 80 are provided around the wafer W in the processing container 2 so as to surround the wafer W. However, if the wafer W can be surrounded, microwaves can be provided. The number of radiation modules 80 is arbitrary. For example, the number of the microwave radiation modules 80 may be single, two to three, or five or more. FIG. 9 shows an example in which four antenna modules 61 are connected to a single microwave radiation module 80C. In FIG. 9, the position of the planar antenna 71 of the antenna module 61 is indicated by a broken line. In the example shown in FIG. 9, the microwave transmission plate 81 and the cover member 82 constituting the microwave radiation module 80C are both a single member formed in an annular shape. The four antenna modules 61 are evenly arranged around the wafer W.

As shown in each of the above modifications, the plasma processing apparatus 1 selects the configuration of the microwave introduction apparatus 5, particularly the combination of the arrangement of the microwave radiation module 80 and the antenna module 61, according to the purpose of processing. be able to. Thereby, local control of the plasma density in the processing container 2 can be easily performed. In the plasma processing apparatus 1, from the viewpoint of facilitating control of the distribution of plasma generated in the processing container 2, the microwave introduction apparatus is arranged so that at least three antenna modules 61 are arranged around the wafer W. 5 is preferable. Further, as the number of antenna modules 61 increases, local control of plasma in the processing container 2 becomes easier.

In the above description, an example in which a plurality of microwave radiation modules 80 are arranged in a concentric manner around the wafer W that is circular in plan view has been described. However, when the object to be processed is, for example, a rectangular flat panel display substrate, the microwave radiation modules 80 can be arranged around the substrate so as to form a square as a whole.

<Gas introduction / exhaust>
As described above, the ceiling portion 11 of the processing container 2 of the plasma processing apparatus 1 is provided with a plurality of gas introduction openings 11b and has nozzles 16 attached to the respective gas introduction openings 11b (FIG. 1). See also). Further, a plurality of exhaust ports 11 a are provided in the ceiling portion 11 of the processing container 2, and the exhaust device 4 is connected thereto. FIG. 10 is a bottom view of the ceiling portion 11 of the plasma processing apparatus 1 of the present embodiment, and shows an arrangement example of the nozzles 16 and the exhaust ports 11a in the ceiling portion 11. In the example shown in FIG. 10, in the ceiling portion 11, 12 nozzles 16 are arranged in a concentric manner on the inner side and 28 nozzles 16 on the outer side. Further, in the ceiling portion 11, one exhaust port 11 a is formed in the central portion, and six exhaust ports 11 a are formed in an intermediate region between the central portion and the peripheral portion. The nozzles 16 and the exhaust ports 11a are alternately arranged concentrically. The arrangement and the number of the nozzles 16 and the exhaust ports 11a in the ceiling portion 11 are not limited to the configuration shown in FIG. 10, and various types such as alternately arranging the nozzles 16 and the exhaust ports 11a in a grid pattern, for example. Can be modified.

As shown in FIG. 10, the surface of the wafer W (surface to be processed) is provided by providing both the nozzle 16 for introducing gas and the exhaust port 11a for exhausting close to each other in the ceiling portion 11 of the processing chamber 2. The residence time of processing gas in the vicinity can be shortened. That is, the processing gas introduced into the processing container 2 from the nozzle 16 can be discharged from the exhaust port 11a (by the exhaust device 4) in a short time. Thus, by shortening the gas residence time in the processing container 2, it becomes possible to improve the film quality in the film forming process. For example, in the case of performing nitridation processing of polysilicon on the wafer W using the plasma processing apparatus 1, the gas residence time is shortened so that the film can be introduced into the film due to oxygen released from the parts in the processing chamber 2. Oxygen contamination can be reduced. In addition, for example, in the case where the oxidation processing of polysilicon on the wafer W is performed using the plasma processing apparatus 1, the oxidation rate can be improved by shortening the gas residence time.

Next, an example of plasma processing in the plasma processing apparatus 1 will be described. Here, the procedure of the plasma processing will be described by taking as an example a case where plasma nitridation processing is performed on the surface of the wafer W using a gas containing nitrogen as the processing gas. First, for example, a command is input from the user interface 92 to the process controller 91 so as to perform plasma nitriding in the plasma processing apparatus 1. Next, the process controller 91 receives this command and reads a recipe stored in the storage unit 93 or a computer-readable storage medium. Next, each end device (for example, the high-frequency bias power supply 25, the gas supply device 3a, the exhaust device 4, and the microwave introduction is introduced from the process controller 91 so that the plasma nitridation process is executed according to the conditions based on the recipe. A control signal is sent to the apparatus 5 or the like.

Next, the gate valve G is opened, and the wafer W is loaded into the processing container 2 through the gate valve G and the loading / unloading port 12a by a transfer device (not shown). The wafer W is transferred to the plurality of support pins 28 and placed on the placement region 17 a of the placement unit 17. Next, the gate valve G is closed, and the inside of the processing container 2 is evacuated by the exhaust device 4. Next, the gas supply mechanism 3 introduces a rare gas and a nitrogen-containing gas at a predetermined flow rate into the processing container 2 through the gas introduction unit 15. The internal space of the processing container 2 is adjusted to a predetermined pressure by adjusting the exhaust amount and the gas supply amount.

Next, the microwave to be introduced into the processing container 2 is generated in the microwave output unit 50. The microwaves are distributed to a plurality of systems (for example, 4 systems) by the distributor 54. The plurality of microwaves output from the distributor 54 of the microwave output unit 50 are input to the plurality of antenna modules 61 of the antenna unit 60 and are introduced into the processing container 2 by each antenna module 61. In each antenna module 61, the microwave propagates through the amplifier unit 62 and the microwave introduction unit 63. The microwave that has reached the antenna section 65 of the microwave introduction section 63 is directed by the cover member 82 of the microwave radiation module 80 through the slot 71 a of the planar antenna 71 and transmits through the microwave transmission plate 81. Then, the light is emitted from the microwave radiation surface 81 a toward the space above the wafer W in the processing chamber 2. In this way, microwaves are individually introduced into the processing container 2 from the respective antenna modules 61. In each antenna module 61, the microwave distributed by the distributor 54 can be individually amplified by the amplifier unit 62, so that the power of the microwave introduced into the processing container 2 can be individually controlled. Therefore, the plasma density in the processing container 2 can be locally controlled.

As described above, the microwaves introduced into the processing container 2 from a plurality of parts around the wafer W form an electromagnetic field at a position immediately above the wafer W in the processing container 2, respectively. Thereby, the processing gas such as an inert gas or a nitrogen-containing gas introduced into the processing container 2 is turned into plasma. Then, the silicon surface of the wafer W is nitrided by the action of active species in the plasma, such as radicals or ions, to form a thin silicon nitride film SiN.

When a control signal for terminating the plasma processing is sent from the process controller 91 to each end device of the plasma processing apparatus 1, the generation of microwaves is stopped and the supply of the rare gas and the nitrogen-containing gas is stopped and the wafer is stopped. The plasma processing for W ends. Next, the gate valve G is opened, and the wafer W is unloaded by a transfer device (not shown).

Note that the oxidation treatment can be performed on the wafer W by using an oxygen-containing gas instead of the nitrogen-containing gas. Further, by using the film forming raw material gas, the film forming process can be performed on the wafer W by the plasma CVD method.

In the plasma processing apparatus 1 of the present embodiment, the microwave radiation module 80 of the microwave introducing device 5 is disposed around the wafer W that is the object to be processed, and the microwave is introduced from the periphery of the wafer W. To do. By arranging the microwave introduction device 5 at the lower portion of the processing container 2, it is no longer essential to provide a microwave introduction mechanism in the ceiling portion 11 of the processing container 2. Therefore, the ceiling portion 11 can be used for other mechanisms, and as illustrated in FIG. 10, gas can be introduced / exhausted from the ceiling portion 11 of the processing container 2, and freedom in designing the apparatus. It became possible to greatly improve the degree.

Next, the effect in this embodiment will be described. As described above, in the plasma processing apparatus 1 according to the present embodiment, microwaves are introduced into the processing container 2 through the antenna module 61 and the microwave radiation module 80 mounted on the bottom wall portion 13 of the processing container 2. Is done. The effects of such a configuration will be described below in comparison with a plasma processing apparatus of a comparative example. Note that a plasma processing apparatus that introduces microwaves from above the processing container is referred to as a plasma processing apparatus of a comparative example.

FIG. 11 is a cross-sectional view schematically showing a configuration of a plasma processing apparatus of a comparative example. The plasma processing apparatus 501 of the comparative example includes a processing container 502, a mounting table 521, and a support member 522. The plasma processing apparatus 501 includes a microwave introducing device 505 instead of the microwave introducing device 5 shown in FIG. The microwave introduction device 505 is provided on the upper portion of the processing container 502. The microwave introducing device 505 is a microwave introducing device having a known configuration including only one microwave transmitting plate 573 made of quartz, for example.

In the plasma processing apparatus 501, since the microwave transmission plate 573 of the microwave introduction apparatus 505 is provided on the upper part of the processing container 502, the processing gas cannot be introduced or exhausted from the upper part of the processing container 502. In many cases, in the plasma processing apparatus 501, the processing gas is introduced from the side of the processing container 502, or a shower plate (not shown) is interposed between the mounting table 521 and the microwave transmission plate 573. Limited to the method. Further, in many cases, the exhaust of gas is limited to a method performed from the bottom of the processing container 502.

Further, in the plasma processing apparatus 501, since the microwave transmission plate 573 is present immediately above the mounting table 521, for example, the thin film attached to the microwave transmission plate 573 is peeled off while the plasma oxidation process and the plasma nitridation process are repeated, and the wafer is removed. It falls on W and becomes a particle generation source.

In the plasma processing apparatus 501, the microwave introduction apparatus 505 is provided on the upper part of the processing container 502, and since the processing container 502 includes the mounting table 521 on which the wafer W is mounted and the support member 522, The volume of the processing container 502 becomes large and it is difficult to reduce the size.

As described above, in the plasma processing apparatus 501 of the comparative example, since the microwave introduction mechanism is provided in the ceiling portion of the processing container 502, it is difficult to reduce the volume of the processing container, and other mechanisms are mounted on the ceiling. It was difficult to provide in the part. As a result, the degree of freedom in device design was greatly restricted. Further, in the plasma processing apparatus 501, it is necessary to provide a microwave transmission plate 573 that may be a particle generation source immediately above the mounting table 521, and thus it is difficult to take measures against particles. On the other hand, in the plasma processing apparatus 1 of the present embodiment, a microwave introduction mechanism is provided on the bottom wall portion 13 of the processing container 2, and microwaves for generating plasma in the processing container 2 are generated around the wafer W. It was set as the structure introduce | transduced from the provided microwave radiation module 80. FIG. By adopting such a configuration, the plasma processing apparatus 1 can significantly reduce the volume of the processing vessel 2 as compared to the microwave plasma processing apparatus having a conventional configuration. In addition, since it is not essential to provide a microwave introduction mechanism in the ceiling portion 11 of the processing container 2, a gas introduction portion for introducing gas and an exhaust portion for exhausting gas are provided in the ceiling portion 11 of the processing vessel 2. Gas can be introduced and exhausted through the ceiling 11. Furthermore, since it is not necessary to arrange a microwave transmission plate immediately above the wafer W, generation of particles due to the microwave transmission plate can be reduced.

Next, with reference to FIGS. 12A to 12C, the effects of the plasma processing apparatus 1 of the present embodiment will be described in more detail with reference to examples of arrangement of the gas introduction part and the exhaust part in the processing container 2. In the plasma processing apparatus 1 shown in FIG. 1, the gas is introduced into the processing container 2 and exhausted through the ceiling portion 11. However, since the plasma processing apparatus of the present invention has a high degree of freedom in apparatus design, for example, more variations can be adopted for the configuration of the gas introduction part and the exhaust part.

12A to 12C schematically show a modified plasma processing apparatus in which the gas introduction position and the exhaust position are different from the plasma processing apparatus 1 of FIG. 1, and the other configuration is the first plasma processing apparatus. Same as 1. In FIGS. 12A to 12C, the gas introduction part 94 and the exhaust part 95 are used only in the meaning of symbolically indicating a rough place where they are disposed. 12A to 12C, the specific arrangement of nozzles and exhaust ports can be made more complicated as illustrated in FIG. 10, for example.

(Third Modification)
FIG. 12A is a mode in which the gas introduction part 94 is provided in the ceiling part 11 of the processing container 2 and the exhaust part 95 is provided in the side wall part 12 of the processing container 2. In the third modification, even if particles such as film peeling occur on the microwave transmission plate 81 of the microwave radiation module 80, the processing gas is introduced from the ceiling portion 11 of the processing container 2, and the side wall portion 12 is introduced. The flow of gas exhausted from the provided exhaust unit 95 can make it difficult for particles to adhere to the surface of the wafer W. Further, since the gas is exhausted from the side wall portion 12 of the processing container 2, the probability that the particles fall onto the surface of the wafer W can be reduced because the exhaust portion 95 does not exist immediately above the wafer W.

(Fourth modification)
FIG. 12B is a mode in which the gas introduction part 94 is provided in the side wall part 12 of the processing container 2 and the exhaust part 95 is provided in the ceiling part 11 of the processing container 2. In the fourth modified example, gas is exhausted from the ceiling part 11 of the processing container 2. However, since the degree of freedom of arrangement of the exhaust part 95 in the ceiling part 11 is high, for example, the position directly above the wafer W is removed and the exhaust port is opened. Can be provided. Thereby, contamination of the wafer W due to falling particles can be reduced.

(Fifth modification)
FIG. 12C shows a mode in which the gas introduction part 94A is provided in the ceiling part 11 of the processing container 2, the gas introduction part 94B is provided in the side wall part 12 of the processing container 2, and the exhaust part 95 is provided in the bottom wall part 13 of the processing container 2. is there. In the fifth modification, a certain type of gas can be introduced from the gas introduction unit 94A, and a gas of the same type or a different type from the gas introduced from the gas introduction unit 94A can be introduced from the gas introduction unit 94B. This modification is effective for a process using a plurality of gases simultaneously. In addition, since the gas is exhausted from the bottom wall portion 13 of the processing container 2, the probability that the particles fall onto the surface of the wafer W can be reduced because the exhaust portion 95 does not exist immediately above the wafer W.

As shown in FIGS. 12A to 12C, by introducing a microwave introduction mechanism to the bottom wall portion 13 of the processing vessel 2, gas can be introduced and exhausted from the ceiling portion 11 and the side wall portion 12 in various combinations. Is possible. The modes of gas introduction / exhaustion listed in the third to fifth modifications of FIGS. 12A to 12C are merely examples, and combinations of these modifications are possible.

Further, in the plasma processing apparatus of the present embodiment, since the degree of freedom in apparatus design is greatly improved, various mechanisms are provided on the ceiling portion 11 of the processing container 2 in addition to the gas introduction / exhaust mechanism. Can do. For example, various mechanisms such as a measuring instrument for monitoring the film thickness of the wafer W and a measuring instrument for monitoring the state of plasma in the processing container 2 can be provided on the ceiling portion 11.

[Second Embodiment]
Next, a plasma processing apparatus according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a cross-sectional view showing a schematic configuration of the plasma processing apparatus 1A in the present embodiment, and corresponds to FIG. 1 of the first embodiment. FIG. 14 is an explanatory diagram showing configurations of the microwave output unit 50A and the antenna module 61 of the microwave introduction device 5A of the present embodiment, and is a diagram that substantially corresponds to FIG. 3 of the first embodiment.

In the plasma processing apparatus 1 according to the first embodiment, a distributor 54 is provided in the microwave output unit 50 of the microwave introduction apparatus 5, and the microwaves are distributed to the plurality of antenna modules 61 and then the plurality of microwave radiation modules. 80 to supply. On the other hand, in the plasma processing apparatus 1A of the second embodiment, a plurality of microwave introduction apparatuses 5A are provided, and microwaves are supplied from one antenna module 61 to one microwave radiation module 80. Other configurations of the plasma processing apparatus 1A according to the present embodiment are the same as those of the plasma processing apparatus 1 according to the first embodiment, and therefore, in FIGS. 13 and 14, the configurations are the same as those in FIGS. Are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, the configuration of the amplifier section 62 of the antenna module 61 shown in FIG. 14 may be further simplified.

As shown in FIGS. 13 and 14, in the plasma processing apparatus 1A of the present embodiment, a distributor is not provided in the microwave output unit 50A of the microwave introduction apparatus 5A. The microwave introduction device 5A is configured to supply microwaves from one microwave output unit 50A to one microwave radiation module 80 via one antenna module 61. As described above, in the plasma processing apparatus 1A, it is easy to independently control the power and frequency of the microwaves radiated from each microwave radiation module 80 by providing the plurality of microwave introduction apparatuses 5A independently. become. Therefore, the density of plasma generated by the microwaves radiated from the microwave radiation module 80 in the processing container 2 can be easily controlled locally for each individual microwave radiation module 80. In addition, the plasma processing apparatus 1A of the present embodiment can be used, for example, when a plurality of objects to be processed are simultaneously processed in the same processing container.

Other configurations, operations, and effects in the present embodiment are the same as those in the first embodiment. As a modification of the plasma processing apparatus 1A of the present embodiment, the microwave radiation module 80 can be shared in the plurality of microwave introduction apparatuses 5A.

[Third Embodiment]
Next, with reference to FIG.15 and FIG.16, the plasma processing apparatus which concerns on the 3rd Embodiment of this invention is demonstrated. FIG. 15 is a cross-sectional view showing a schematic configuration of plasma processing apparatus 1B in the present embodiment, and corresponds to FIG. 1 of the first embodiment. FIG. 16 is an enlarged cross-sectional view showing a main part including the microwave introduction part 63 and the microwave radiation module 80 of the plasma processing apparatus 1B of the present embodiment, which is substantially the same as FIG. 4 of the first embodiment. It is a corresponding figure.

In the plasma processing apparatus 1 </ b> B of the present embodiment, a DC application unit 83 as a DC voltage application unit and a variable direct current electrically connected to the DC application unit 83 are provided on the bottom wall 13 around the mounting unit 17. And a power supply 85. That is, the plasma processing apparatus 1B includes a processing container 2 that accommodates the wafer W, a placement unit 17 that places the wafer W inside the processing container 2, and a gas supply mechanism 3 that supplies gas into the processing container 2. An exhaust apparatus 4 for evacuating the inside of the processing container 2; a microwave introducing apparatus 5 for generating a microwave for generating plasma in the processing container 2 and introducing a microwave into the processing container 2; A DC application unit 83 provided on the bottom wall 13 between the mounting unit 17 and the microwave radiation module 80, and a control unit 8 that controls each component of the plasma processing apparatus 1B are provided. Since the other configuration of the plasma processing apparatus 1B of the present embodiment is the same as that of the plasma processing apparatus 1 according to the first embodiment, in FIGS. 15 and 16, the same configuration as that of FIGS. The same reference numerals are given and description thereof is omitted.

The DC application unit 83 is made of, for example, a conductive material such as metal, surrounds the mounting unit 17, and is provided, for example, in an annular shape so as to be interposed between the microwave radiation module 80 and the mounting unit 17. . The DC application unit 83 is embedded in the bottom wall portion 13 so that the upper surface thereof is exposed in the processing container 2. An insulating material 84 is provided between the bottom wall portion 13 and the DC application portion 83 to be insulated, and is in an electrically floating state with respect to the bottom wall portion 13 at the ground potential. The variable DC power supply 85 is configured to be turned on / off by a switch unit (not shown), and applies a negative DC voltage to the DC application unit 83, for example.

In the plasma processing apparatus 1B of the present embodiment, the microwave from the microwave transmission plate 81 is easily propagated in the direction of the wafer W by applying a DC voltage from the variable DC power supply 85 to the DC applying unit 83. Can do. The microwave radiated from the microwave radiation surface 81a of the microwave transmission plate 81 is a metal surface (bottom wall) exposed between the microwave transmission plate 81 and the wafer W as shown by a thick arrow in FIG. The inner surface S ′ around the wafer W in the part 13 and the DC application part 83 propagates in the surface wave mode. Thus, the surface wave propagating on the metal surface is guided by a sheath (not shown) existing between the plasma and the metal surface. That is, the surface wave propagates between the low electron density layer having a low dielectric constant present in the sheath and the plasma. In the present embodiment, it is possible to increase the sheath thickness by providing a DC applying unit 83 around the placement region 17a and applying a negative voltage from the variable DC power supply 85, for example. By enlarging the sheath thickness, the surface wave can be efficiently guided to the vicinity of the wafer W along the sheath. In this way, by providing the DC application unit 83 and applying a DC voltage thereto, the sheath thickness can be adjusted, and the propagation efficiency of the microwave in the surface wave mode can be increased.

Other configurations, operations, and effects in the present embodiment are the same as those in the first embodiment. Note that, as in the present embodiment, the configuration in which the DC application unit 83 is provided on the bottom wall portion 13 around the placement unit 17 is also applied to the plasma processing apparatus 1A of the second embodiment (see FIG. 13). Is possible.

[Fourth Embodiment]
Next, a plasma processing apparatus according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 17 is a cross-sectional view showing a schematic configuration of a plasma processing apparatus 1C according to the present embodiment, and corresponds to FIG. 1 of the first embodiment.

In the first to third embodiments, the whole microwave radiation module 80 is configured to be accommodated in the processing container 2, but in the present embodiment, most of the microwave radiation module 80 is processed. The container 2 is mounted on the outside of the container 2. That is, the plasma processing apparatus 1 </ b> C includes a processing container 2 that accommodates the wafer W, a placement unit 17 that places the wafer W inside the processing container 2, and a gas supply mechanism 3 that supplies gas into the processing container 2. An exhaust device 4 for evacuating the inside of the processing vessel 2, a microwave for generating plasma in the processing vessel 2, and a microwave introducing device 5 for introducing the microwave into the processing vessel 2, And a control unit 8 that controls each component of the plasma processing apparatus 1C. In the plasma processing apparatus 1 </ b> C of the present embodiment, the microwave radiation module 80 of the microwave introduction device 5 is attached to the lower end of the side wall portion 12 from the outside. More specifically, as shown in FIG. 17, in the plasma processing apparatus 1 </ b> C, the cover member 82 of the microwave radiation module 80 is in contact with the lower end of the side wall portion 12, and the main body container 66 of the microwave introduction portion 63 of the antenna module 61. The microwave introduction device 5 is disposed so that the side wall is in contact with the side end of the bottom wall portion 13. The outer peripheral side of the cover member 82 of the microwave radiation module 80 is exposed to the external space of the processing container 2. Note that a sealing member (not shown) is provided at the contact portion between the upper surface of the cover member 82 of the microwave radiation module 80 and the lower end of the side wall portion 12 to maintain airtightness. Further, a sealing member (not shown) is also provided at the abutting portion between the main body container 66 of the microwave introduction portion 63 and the side end of the bottom wall portion 13 to maintain airtightness.

In the present embodiment, most of the microwave radiation module 80 protrudes outside the processing container 2. For this reason, the microwave radiation surface 81a of the microwave transmission plate 81 exposed to the space in the processing container 2 and the inner peripheral surface of the cover member 82 are continuous with the inner peripheral surface of the side wall portion 12 of the processing container 2 without a step. It is the same. The inner diameter of the processing chamber 2 (the distance between the side wall portions 12 facing each other) matches the distance between the microwave radiation surfaces 81a facing each other with the wafer W interposed therebetween. However, the positions of the microwave radiation surface 81a of the microwave transmission plate 81 and the inner peripheral surface of the cover member 82 may not necessarily coincide with the position of the inner peripheral surface of the side wall portion 12 of the processing container 2 in the horizontal direction. Good. Since other configurations in the plasma processing apparatus 1C of the present embodiment are the same as those of the plasma processing apparatus 1 according to the first embodiment, the same reference numerals are given to the same configurations in FIG. 17 as in FIG. The description is omitted.

In the plasma processing apparatus 1C of the present embodiment, for example, the diameter of the processing container can be significantly reduced as compared with the plasma processing apparatus 501 of the comparative example shown in FIG. In the plasma processing apparatus 501 of the comparative example, a microwave is introduced from the microwave transmission plate 573 of the microwave introduction apparatus 505 provided on the upper part of the processing container 502, and plasma P is generated inside the processing container 502. At this time, the plasma density in the processing container 502 becomes substantially zero on the inner surface of the side wall portion 512. In consideration of the uniformity of processing within the wafer W surface, it is necessary to maintain a necessary plasma density (preferably a uniform plasma density) on the entire surface of the wafer W placed on the mounting table 521. For that purpose, as shown in FIG. 11, it is necessary to generate plasma P having a diameter sufficiently larger than the diameter of the wafer W in the processing chamber 502. In order to generate plasma having a diameter sufficiently larger than the diameter of the wafer W in the processing container 502, it is necessary to leave a sufficient space between the edge of the wafer W and the side wall portion 512 of the processing container 502. Necessary. That is, as shown in FIG. 11, in the plasma processing apparatus 501 of the comparative example, a sufficient distance is secured between the mounting table 521 and the side wall portion 512 of the processing container 502 in consideration of the size of the plasma P. It is necessary to keep.

On the other hand, in the plasma processing apparatus 1C of the present embodiment, the microwave radiation module 80 is provided around the wafer W, and the microwave is introduced from the position close to the edge of the wafer W toward the wafer W in the horizontal direction. Then, plasma is generated immediately above the wafer W. For this reason, even if the position of the side wall portion 12 of the processing container 2 is close to the edge of the wafer W, there is almost no fear of adversely affecting the uniformity of processing within the wafer W surface. Therefore, in the plasma processing apparatus 1C of the present embodiment, the inner diameter of the processing container 2 may be smaller than that of the plasma processing apparatus 501 of the comparative example, and the internal volume can be greatly reduced. Therefore, the processing container 2 can be downsized. Further, in the plasma processing apparatus 1C of the present embodiment, since the internal volume of the processing container 2 can be reduced as compared with the plasma processing apparatus 501 of the comparative example, the residence time of the processing gas in the processing container 2 can be shortened. For example, when used as a film forming apparatus, an improvement in film quality can be expected.

Further, in the plasma processing apparatus 1C of the present embodiment, since most of the microwave radiation module 80 is placed outside the processing container 2, for example, the plasma processing apparatuses 1 and 1 of the first to third embodiments are used. Compared with 1A and 1B, the volume of the internal space of the processing container 2 can be further reduced.

Other configurations, operations, and effects in the present embodiment are the same as those in the first embodiment. Note that, as in the present embodiment, the configuration in which the microwave radiation module 80 is attached to the lower end of the side wall portion 12 is the same as that of the plasma processing apparatus 1A of the second embodiment (see FIG. 13) or the third embodiment. The present invention can also be applied to the plasma processing apparatus 1B (see FIG. 15).

The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the plasma processing apparatus of the present invention is not limited to a case where a semiconductor wafer is used as an object to be processed, and can also be applied to a plasma processing apparatus using, for example, a solar cell panel substrate or a flat panel display substrate as an object to be processed.

Also, not only vacuum processing but atmospheric pressure plasma can be used.

Further, in the plasma processing apparatus of each of the above embodiments, the mounting portion 17 is provided on the bottom wall portion 13 of the processing container 2, but a metal stage or base is provided in the processing container 2, and the stage or base is provided. A microwave may be radiated from a microwave radiation module arranged with its height aligned around the wafer W placed on the part.

In each of the above embodiments, the microwave introduction mechanism is not provided in the ceiling portion 11 of the processing container 2. However, in combination with the microwave introduction device 5, it does not preclude providing a microwave introduction mechanism on the ceiling portion 11 of the processing container 2 as an auxiliary.

This international application claims priority based on Japanese Patent Application No. 2011-181478 filed on August 23, 2011, the entire contents of which are incorporated herein by reference.

Claims (17)

1. A processing container for storing an object to be processed;
   A mounting section for mounting the object to be processed in the processing container;
   A gas supply mechanism for supplying a processing gas into the processing container;
   A microwave introduction device for generating a microwave for generating a plasma of the processing gas in the processing container and for introducing the microwave into the processing container;
   The microwave introduction device is
   A dielectric window member disposed around the object to be processed and transmitting microwaves into the processing container;
   A conductor member for regulating the microwave radiated into the processing container through the dielectric window member so as to be directed to the target object in a direction parallel to the surface of the target object;
   A plasma processing apparatus having a microwave radiation module.
2. The microwave introduction device is
   A microwave output unit for generating and outputting a microwave;
   One or a plurality of antenna modules that are attached to the lower part of the processing container from the outside and supply the microwaves output from the microwave output unit to the microwave radiation module;
   The plasma processing apparatus according to claim 1, further comprising:
3. The dielectric window member has a microwave radiation surface that is exposed to a space in the processing container and emits microwaves toward the object to be processed.
   The plasma processing apparatus according to claim 1, wherein the conductor member covers a surface of the dielectric window member excluding the microwave radiation surface.
4. The plasma processing apparatus according to claim 3, wherein the microwave radiation surface has a shape corresponding to a shape of an edge of an object to be processed.
5. The plasma processing apparatus according to claim 4, wherein the object to be processed has a circular shape in plan view, and the microwave radiation surface has a shape curved in an arc shape.
6. The plasma processing apparatus according to claim 2, comprising a plurality of the microwave radiation modules so as to surround a target object.
7. The plasma processing apparatus according to claim 6, wherein one or a plurality of the antenna modules are connected to one microwave radiation module.
8. The plasma processing apparatus according to claim 6, comprising at least three antenna modules.
9. The plasma processing apparatus according to claim 1, wherein a lower end of the dielectric window member is disposed at a height position equal to or higher than a height of an upper surface of the object to be processed placed on the placement portion.
10. A gas introduction part for introducing a processing gas supplied from the gas supply mechanism is provided in a ceiling part of the processing container;
    The plasma processing apparatus according to claim 1, wherein an exhaust port connected to an exhaust apparatus for evacuating the inside of the processing container is provided in a ceiling portion of the processing container.
11. 2. The plasma processing apparatus according to claim 1, wherein an exhaust port connected to an exhaust device for evacuating and exhausting the inside of the processing container is provided on a side wall or a bottom wall of the processing container.
12. The plasma processing apparatus according to claim 1, wherein the placement unit is provided on a bottom wall portion of the processing container.
13. The plasma processing apparatus according to claim 1, further comprising a high frequency power supply unit that supplies high frequency power to the mounting unit.
14. 2. The plasma processing apparatus according to claim 1, further comprising a DC voltage application unit to which a DC voltage is applied between the mounting unit and the microwave radiation module.
15. A plasma processing method of processing an object to be processed using a plasma processing apparatus,
    The plasma processing apparatus includes a processing container that accommodates an object to be processed, a placement unit that places the object to be processed in the processing container, a gas supply mechanism that supplies a processing gas into the processing container, and the processing A microwave for generating a plasma for generating plasma of the processing gas in a container, and a microwave introduction device for introducing the microwave into the processing container,
    The microwave introducing device is disposed around the object to be processed, transmits a microwave and radiates it into the processing container, and is radiated into the processing container through the dielectric window member. And a conductor member that restricts the microwave to be directed to the object in a direction parallel to the surface of the object to be processed.
16. A microwave introduction device for generating a microwave for generating plasma of a processing gas in a processing container that accommodates an object to be processed, and for introducing the microwave into the processing container,
    A dielectric window member that is disposed around the object to be processed and transmits microwaves into the processing container and microwaves radiated into the processing container through the dielectric window member are processed. A microwave radiation module comprising: a conductor member that regulates toward the object to be processed in a direction parallel to the surface of the substrate.
17. A microwave output unit that generates and outputs a microwave, and one or a plurality of microwaves that are attached to the lower part of the processing container from the outside and that are output from the microwave output unit are supplied to the microwave radiation module The microwave introduction device according to claim 16, further comprising: an antenna module.
    
    

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