KR20210129179A - plasma processing device - Google Patents

Abstract

A plasma processing apparatus for vacuum processing an object disposed in a processing chamber using plasma, comprising: a container body having an opening in a wall forming the processing chamber; and a slit installed to block the opening and penetrating in the thickness direction; A plasma processing apparatus comprising: a metal plate having a metal plate; a dielectric plate blocking the slit of the metal plate from the outside of the processing chamber; .

Description

plasma processing device

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

Plasma processing in which a high-frequency current is passed through an antenna, an inductively coupled plasma (abbreviated, ICP) is generated by an induced electric field generated thereby, and the inductively coupled plasma is used to treat a target object such as a substrate A device has been conventionally proposed. As such a plasma processing apparatus, in Patent Document 1, an antenna is disposed outside a vacuum container, and a high-frequency magnetic field generated from the antenna is transmitted into the vacuum container through a dielectric window provided to block the opening of the side wall of the vacuum container, thereby entering the processing chamber. Generating a plasma is disclosed.

Japanese Patent Laid-Open No. 2017-004665

However, in the plasma processing apparatus described above, since the dielectric window is used as a part of the sidewall of the vacuum vessel, the dielectric window needs to have sufficient strength to withstand the pressure difference between the inside and outside of the vessel when the inside of the vacuum vessel is evacuated. In particular, since the dielectric material constituting the dielectric window is ceramics or glass with low toughness, it is necessary to increase the thickness of the dielectric window sufficiently to provide sufficient strength to withstand the above-described differential pressure. Therefore, as the distance from the antenna to the processing chamber in the vacuum container increases, the intensity of the induced electric field in the processing chamber decreases, and there is a problem that the efficiency of plasma generation decreases.

The present invention has been made in view of such a problem, and its main object is to provide a plasma processing apparatus capable of efficiently supplying a high-frequency magnetic field generated from the antenna to the processing chamber when the antenna is disposed outside the processing chamber.

That is, the plasma processing apparatus according to the present invention vacuum-processes a target object disposed in a processing chamber using plasma, and includes a container body having an opening in a wall forming the processing chamber, and installed so as to block the opening and have a thickness A metal plate having a slit penetrating in the direction, a dielectric plate blocking the slit of the metal plate from the outside of the processing chamber, and installed outside the processing chamber to face the metal plate and connected to a high-frequency power supply to generate a high-frequency magnetic field It is characterized in that it is provided with an antenna.

That is, in the plasma processing apparatus according to the present invention, a magnetic field transmission window for transmitting a high-frequency magnetic field generated from an antenna to the processing chamber side is formed by a slit formed in a metal plate and a dielectric plate disposed thereon. With such a configuration, since a part of the member forming the magnetic field transmission window is made of a metal material having greater toughness than a dielectric material such as ceramics, the thickness of the magnetic field transmission window can be reduced compared to the case of configuring the magnetic field transmission window only with a dielectric material. have. Thereby, the distance from the antenna to the processing chamber can be shortened, and the high-frequency magnetic field generated from the antenna can be efficiently supplied into the processing chamber.

In addition, since the metal plate is provided to block the opening of the container body, all members surrounding the processing chamber serving as the plasma generating space can be electrically grounded. Thereby, the influence on the plasma by the voltage of the antenna can be reduced, and it is possible to reduce the electron temperature and reduce the ion energy.

It is preferable that the slit is formed so as to be positioned between the antenna and the processing chamber when viewed from the thickness direction. In this case, the high-frequency magnetic field generated from the antenna can be more efficiently supplied into the processing chamber.

It is preferable that the antenna forms a linear shape, and a plurality of the slits are formed parallel to each other. In this case, since the high-frequency magnetic field can be more uniformly supplied into the processing chamber, the plasma density generated in the processing chamber can be made more uniform.

It is preferable that a flow path through which the cooling fluid can flow is formed inside the metal plate.

In this case, the resistance heat generated by the induced current flowing through the metal plate can be transferred to the cooling fluid and released. Thereby, the temperature rise of the metal plate in use can be suppressed, the temperature rise by the radiant heat from the metal plate with respect to a to-be-processed object can be suppressed, and plasma processing can be performed more stably with respect to a to-be-processed object.

As a form of the said metal plate, the thing formed so that the said flow path may pass at least between mutually adjacent slits is mentioned.

When viewed from the thickness direction, when a slit is formed between the antenna and the processing chamber, a relatively large induced current flows between adjacent slits in the metal plate (especially directly under the antenna), and the amount of heat generated in this portion is greatest. . Therefore, by forming a flow path so that it may pass between mutually adjacent slits, a metal plate can be cooled efficiently and a temperature rise can be suppressed efficiently.

The plasma processing apparatus includes a window member attached to the container body to close the opening and forming a magnetic field transmission window through which a high-frequency magnetic field generated from the antenna is transmitted into the processing chamber, the window member comprising: the metal plate; It is preferable to have the said dielectric plate, and the holding frame which holds the said metal plate and the said dielectric plate.

In this case, since the window member forming the magnetic field transmission window and the container body are different members, even if the metal plate is consumed or contaminated due to corrosion by gas or deterioration by heat, it is separated for each window member to facilitate exchange and cleaning of the metal plate. can be done

When viewed from the thickness direction, as the angle between the slit and the antenna becomes smaller (that is, closer to parallel), the induced current flowing through the metal plate increases to cancel the high-frequency magnetic field generated from the antenna, and the intensity of the high-frequency magnetic field supplied to the processing chamber increases. There is a risk of deterioration.

Therefore, when viewed from the thickness direction, the angle between the slit and the antenna is preferably 30° or more and 90° or less. In this way, when viewed from the thickness direction, the slit is formed so as to intersect the antenna, so that the induced current flowing through the metal plate along the axial direction of the antenna is interrupted by the slit. Thereby, the induced current flowing through the metal plate can be reduced, and the intensity of the high-frequency magnetic field supplied to the processing chamber can be improved. It is preferable that the angle between the slit and the antenna is larger (ie, closer to vertical). The angle is more preferably 45° or more and 90° or less, and still more preferably about 90°.

When the width of the slit is too large with respect to the thickness of the metal plate, the electric field generated between the antenna and the metal plate easily enters the processing chamber through the slit, which may affect the generated plasma.

Therefore, it is preferable that it is below the plate thickness of the said metal plate, and, as for the width dimension of the said slit, it is more preferable that it is 1/2 or less. Thereby, mixing of the electric field into the processing chamber can be suppressed, and the influence on the generated plasma can be reduced. In addition, the "width dimension of a slit" as used in this specification means the length of the slit in the direction along the antenna in the location overlapping with an antenna, when viewed from the thickness direction.

It is preferable that the width dimension of the said metal plate between mutually adjacent slits is 15 mm or less, and it is more preferable that it is 5 mm or less.

In this way, the induced current flowing through the metal plate can be made smaller, and the intensity of the high-frequency magnetic field supplied to the processing chamber can be further improved.

According to the present invention as described above, it is possible to provide a plasma processing apparatus capable of efficiently supplying a high-frequency magnetic field generated from the antenna to the processing chamber when the antenna is disposed outside the processing chamber.

1 is a cross-sectional view orthogonal to the longitudinal direction of an antenna schematically showing the overall configuration of a plasma processing apparatus of the present embodiment.
Fig. 2 is a cross-sectional view taken along the longitudinal direction of the antenna schematically showing the overall configuration of the plasma processing apparatus of the embodiment.
3 is a cross-sectional view taken along the longitudinal direction of the antenna schematically showing the configuration of a window member of the plasma processing apparatus of the embodiment.
4 is a plan view from the antenna side schematically showing the configuration of a window member of the plasma processing apparatus of the embodiment.
5 is a plan view schematically illustrating the relationship between the antenna and the slit of the plasma processing apparatus of the embodiment.
It is a top view which shows typically the structure of the cooling mechanism which cools the metal plate of the same embodiment.
7 is a cross-sectional view taken along the longitudinal direction of an antenna schematically showing the overall configuration of a plasma processing apparatus according to another embodiment.
8 is a plan view schematically illustrating the relationship between an antenna and a slit of a plasma processing apparatus according to another embodiment.
9 : is a top view (a) and front view (b) which show typically the structure of the metal plate of another embodiment.
10 is a graph for explaining the influence of the length between slits on the intensity of the high-frequency magnetic field.
It is a graph explaining the influence of the intensity|strength of a high frequency magnetic field by a slit angle.
12 is a graph for explaining the influence of the slit width on the intensity of the high-frequency magnetic field.
It is a graph explaining the influence on the intensity|strength of a high frequency magnetic field by the thickness of a metal plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plasma processing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In addition, the plasma processing apparatus described below is for realizing the technical idea of this invention, and unless otherwise stated, this invention is not limited to the following. In addition, the content described in one embodiment is applicable also to another embodiment. In addition, the size, positional relationship, etc. of the member shown by each figure may be exaggerated in order to make description clear.

<Device configuration>

The plasma processing apparatus 100 according to the present embodiment performs vacuum processing on an object W such as a substrate using an inductively coupled plasma P. Here, a board|substrate is a board|substrate for flat panel displays (FPD), such as a liquid crystal display and organic electroluminescent display, the flexible board|substrate for flexible displays, etc., for example. The processing to be performed on the substrate is, for example, film formation by plasma CVD, etching, ashing, sputtering, or the like.

In addition, the plasma processing apparatus 100 of this embodiment is a plasma CVD apparatus for film formation by plasma CVD, a plasma etching apparatus for etching, a plasma ashing apparatus for ashing, and a plasma ashing apparatus for performing sputtering. It is also called a plasma sputtering device.

Specifically, as shown in FIG. 1 , the plasma processing apparatus 100 includes a vacuum vessel 2 having a processing chamber 1 that is evacuated and into which gas G flows, and an antenna installed outside the processing chamber 1 . 3) and a high frequency power supply 4 for applying a high frequency to the antenna 3 are provided. The vacuum container 2 is provided with a magnetic field transmission window 5 through which the high-frequency magnetic field generated from the antenna 3 is transmitted into the processing chamber 1 . When a high frequency is applied to the antenna 3 from the high frequency power supply 4 , a high frequency magnetic field generated from the antenna 3 passes through the magnetic field transmission window 5 and is formed in the processing chamber 1 , thereby creating an induced electric field in the space within the processing chamber 1 . is generated, thereby generating an inductively coupled plasma P.

The vacuum container 2 includes a container body 21 and a window member 22 forming a magnetic field transmission window 5 .

The container body 21 is, for example, a metal container, and the processing chamber 1 is formed inside by the wall (inner wall). An opening 211 penetrating in the thickness direction is formed in the wall of the container body 21 (here, the upper wall 21a). The window member 22 is detachably attached to the container body 21 so as to close this opening 211 . Further, the container body 21 is electrically grounded, and the window member 22 and the container body 21 are vacuum-sealed by a gasket such as an O-ring or an adhesive.

The vacuum container 2 is configured such that the processing chamber 1 is evacuated by the vacuum evacuation device 6 . Further, the vacuum vessel 2 is configured such that the gas G is introduced into the processing chamber 1 via, for example, a flow rate regulator (not shown) and a plurality of gas introduction ports 212 formed in the vessel body 21 , have. What is necessary is just to set the gas G according to the content of the process performed to the board|substrate W. For example, in the case of forming a film on a substrate by a plasma CVD method, a gas G is a gas or a dilution gas to the raw material it is diluted gas (e.g. H _2). For more specific examples, when the source gas is SiH ₄ , a Si film, in the case of SiH ₄ +NH ₃ , a SiN film, in the case of SiH ₄ +O ₂ , a SiO ₂ film, and in _{the case of SiF 4} +N ₂ , SiN: An F film (a fluorinated silicon nitride film) can be formed on the substrate, respectively.

Moreover, in the vacuum container 2, the board|substrate holder 7 which holds the board|substrate W is provided. You may make it apply a bias voltage from the bias power supply 8 to the board|substrate holder 7 like this example. The bias voltage is, for example, a negative DC voltage, a negative bias voltage, or the like, but is not limited thereto. With such a bias voltage, for example, it is possible to control the energy when positive ions in the plasma P are incident on the substrate W, and to control the crystallinity of a film formed on the surface of the substrate W, and the like. A heater 71 for heating the substrate W may be provided in the substrate holder 7 .

1 and 2 , a plurality of antennas 3 are provided, and each antenna 3 is disposed outside the processing chamber 1 so as to face the magnetic field transmission window 5 . Here, the distance between each antenna 3 and the magnetic field transmission window 5 is about 2 mm. Each antenna 3 is arranged so as to be substantially parallel to the surface of the substrate W provided in the processing chamber 1 .

Each antenna 3 is of the same configuration, and forms a linear shape with a length of several tens of cm or more. The high frequency power supply 4 is connected to the power feeding end 3a which is one end of the antenna 3 through the matching circuit 41, and the terminal 3b which is the other end is directly grounded. In addition, the terminal part 3b may be grounded through a capacitor|condenser, a coil, etc..

Here, each antenna 3 has a hollow structure in which a flow path through which the cooling liquid CL can flow is formed. Specifically, each antenna 3 includes at least two conductor elements 31 and a capacitor 32 as a quantitative element electrically connected in series with the conductor elements 31 adjacent to each other, as shown in FIG. 2 . Here, each antenna 3 has three conductor elements 31 and two capacitors 32 . Each conductor element 31 has a straight tube shape in which a linear flow path through which a cooling liquid flows is formed, and the material thereof is, for example, copper, aluminum, an alloy thereof, or a metal such as stainless steel, but is limited thereto. No, you can change it appropriately.

By configuring each antenna 3 in this way, simply put, the combined reactance of the antenna 3 becomes a type obtained by subtracting the capacitive reactance from the inductive reactance, so that the impedance of the antenna 3 can be reduced. As a result, even when the antenna 3 is lengthened, an increase in its impedance can be suppressed, the high-frequency current IR easily flows through the antenna 3, and an inductively coupled plasma P is efficiently generated in the processing chamber 1 . can do it

The high frequency power supply 4 can pass a high frequency current IR to the antenna 3 through the matching circuit 41 . Although the frequency of a high frequency is general 13.56 MHz, for example, it is not limited to this, You may change suitably.

Then, in the plasma processing apparatus 100 of the present embodiment, as shown in FIG. 3 , a metal plate 221 and a dielectric plate 222 in which the window member 22 is sequentially provided from the processing chamber 1 side to the antenna 3 side. ) is provided. The metal plate 221 is provided with the slit 221s penetrating through the thickness direction so that the opening part 211 of the container body 21 may be blocked. The dielectric plate 222 is provided on the surface of the metal plate 221 on the antenna 3 side so as to block the slits 221s of the metal plate 221 from the outside of the processing chamber 1 (that is, the antenna 3 side). . In the plasma processing apparatus 100 of the present embodiment, the magnetic field transmission window 5 is formed by the slits 221s of the metal plate 221 and the dielectric plate 222 blocking the slits 221 . That is, the high-frequency magnetic field generated from the antenna 3 passes through the dielectric plate 222 and the slit 221s and is supplied to the processing chamber 1 . In addition, the vacuum in the processing chamber 1 is maintained by the metal plate 221 blocking the opening 211 and the dielectric plate 222 blocking the slits 221s of the metal plate 221 . In the following description, the thickness direction of the metal plate 221 is only called "thickness direction".

The metal plate 221 transmits the high-frequency magnetic field generated from the antenna 3 into the processing chamber 1 , and prevents mixing of an electric field from the outside of the processing chamber 1 into the processing chamber 1 . Specifically, a metal material is rolled (for example, cold rolled or hot rolled) to form a flat plate shape. Although the thickness of the metal plate 221 is made into about 5 mm here, it is not limited to this, You may change suitably according to a specification. The thickness of the metal plate 221 may be a thickness that can withstand the pressure difference between the internal and external pressures of the processing chamber 1 at the time of vacuum processing, and is preferably 1 mm or more.

3 and 4, the metal plate 221 has comprised the shape (here, a square shape) which can cover the whole opening 211 of the container main body 21 in planar view. The area surrounded by the outer peripheral edge of the metal plate 221 is larger than the area of the opening 211 of the container body 21 . Then, the metal plate 221 is provided in contact with the container body 21 so as to surround the periphery of the opening 211 of the container body 21 on the antenna 3 side. The metal plate 221 is disposed so as to be substantially parallel to the surface of the substrate W disposed in the processing chamber 1 . The metal plate 221 and the container body 21 are vacuum-sealed by interposing a sealing structure (not shown) between them. Here, the sealing structure is realized by a sealing member such as an O-ring or a gasket or an adhesive provided between the metal plate 221 and the container body 21 , for example. These sealing members are provided so as to surround the outer peripheral edge of the opening 211 .

In this embodiment, the metal plate 221 is in electrical contact with the container main body 21, and is grounded through the container main body 21. As shown in FIG. Not limited to this, the metal plate 221 may be directly grounded.

The material constituting the metal plate 221 is, for example, one type selected from the group consisting of Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W or Co. A metal or an alloy thereof (for example, a stainless alloy, an aluminum alloy, etc.) may be sufficient. Moreover, it may contain trace elements (unavoidable impurity) which mix according to conditions, such as a raw material, a material, a manufacturing facility. From a viewpoint of improving corrosion resistance and heat resistance, the coating process may be performed with respect to the surface of the process chamber 1 side of the metal plate 221.

As shown in FIG. 4 , the slit 221s has a rectangular shape taking a longitudinal direction in a direction orthogonal to the antenna 3 when viewed from the thickness direction, and is positioned between the antenna 3 and the processing chamber 1 . It is formed directly under the antenna 3 . The slits 221s are formed at positions corresponding to the respective antennas 3 . Specifically, a plurality of slits 221s are formed at positions corresponding to one antenna 3 . More specifically, one or a plurality of slits 221s are formed at positions corresponding to the respective conductor elements 31 of the antenna 3 . In the present embodiment, six slits 221s are formed at positions corresponding to the respective conductor elements 31 . The number of slits 221s is not limited to this, and may be suitably changed according to a specification. Although each slit 221s has comprised the same shape here, a different shape may be sufficient.

The slits 221s are formed parallel to each other at positions corresponding to each antenna 3 (specifically, each conductor element 31). Specifically, as shown in FIG. 5, each slit 221s is formed so that the angle (theta) _s which the longitudinal direction and the antenna 3 make becomes substantially equal when seen from the thickness direction. _{Here, the angle θ s} formed between the slit 221s and the antenna 3 is approximately 90°.

Each slit (221s) is formed so that its width _w approximately equal to d. The width _w of the slit d (221s) is not more than the plate thickness of the metal plate 221 is preferred, more preferably not more than about 1/2, and further preferably less than or equal to about one-third.

Further, the slit (221s) are formed at equal intervals along the antenna 3 at a predetermined pitch d gilchi _p. The "pitch length" here is a distance between the respective center positions of the slits 221s adjacent to each other in the direction along the antenna 3 as shown in FIG. 5 .

Further, the slits 221s are formed so that the width of the metal plate 221 between the slits 221s adjacent to each other is the same. Referred to herein, "the width dimension of a metal plate in between adjacent slits" (also referred to as only "between the slit length" in the following) is a width dimension d _w from the d _p the pitch length of the slit (221s), the slit (221s) minus the length It is preferable that it is 15 mm or less, and, as for the length d _{s between slits, it is more preferable that it is 5 mm or less.}

The plasma processing apparatus 100 of the present embodiment includes a cooling mechanism 9 for cooling the metal plate 221 . Specifically, as shown in FIG. 6 , the cooling mechanism 9 includes a flow path 91 through which the cooling fluid formed inside the metal plate 221 can flow, and a cooling fluid supply for supplying the cooling fluid to the flow path 91 . A mechanism (not shown in the drawing) is provided. The both ends of the flow path 91 are opened on the surface of the metal plate 221, and the fluid for cooling is supplied to the flow path 91 from one opening 91a, and is discharged|emitted from the other opening 91b.

The flow path 91 is formed so that a fluid may flow from one opening 91a to the other opening 91b. Here, the flow path 91 is provided corresponding to each antenna 3 (specifically, the conductor element 31). The flow path 91 includes a first flow path portion 91x formed parallel to the width direction of the slit 221s and a second flow path portion 91y formed parallel to the longitudinal direction of the slit 221s, and a combination of these. It is formed so as to meander between the plurality of slits 221s. The flow path 91 is formed to pass through at least between the slits 221s adjacent to each other. More specifically, the second flow passage portion 91y is formed to pass through the central portion between the slits 221s adjacent to each other. In addition, the cooling fluid supplied to the flow path 91 may be either liquid or gas.

The dielectric plate 222 transmits the high-frequency magnetic field generated from the antenna 3 into the processing chamber 1 and blocks the slits 221s to maintain a vacuum in the processing chamber 1 . Specifically, the dielectric plate 222 has a flat plate shape entirely made of a dielectric material. Here, the thickness of the dielectric plate 222 is made smaller than that of the metal plate 221 , but the present invention is not limited thereto. From the viewpoint of shortening the distance between the antenna 3 and the processing chamber 1, the thinner one is preferable. The thickness of the dielectric plate 222 may be sufficient to withstand the pressure differential inside and outside the processing chamber 1 received from the slit 221s in a state in which the processing chamber 1 is evacuated, and the thickness of the slit 221s It may be set suitably according to specifications, such as a number and length.

Materials constituting the dielectric plate 222 include ceramics such as alumina, silicon carbide and silicon nitride, inorganic materials such as quartz glass and alkali-free glass, and resin materials such as fluororesin (eg, Teflon). It should be material. Further, from the viewpoint of reducing dielectric loss, the material constituting the dielectric preferably has a dielectric tangent of 0.01 or less, more preferably 0.005 or less.

The dielectric plate 222 is provided on the surface of the metal plate 221 on the antenna 3 side so as to cover and block the plurality of slits 221s formed in the metal plate 221 . The dielectric plate 222 and the metal plate 221 are vacuum-sealed by interposing a seal structure (not shown) therebetween. Here, the sealing structure is realized by a sealing member such as an O-ring or a gasket or an adhesive provided between the dielectric plate 222 and the metal plate 221 , for example. These sealing members may be provided so that all of several slit 221s may be enclosed, and may be provided so that a part of several slit 221s may be enclosed. Further, when the dielectric plate 222 is made of a material having high elasticity such as a resin material, the seal structure may be realized by the elastic force of the dielectric plate 222 .

The window member 22 further includes a holding frame 223 for holding the metal plate 221 and the dielectric plate 222 . The holding frame 223 presses and holds the metal plate 221 and the dielectric plate 222 against the upper surface 21b of the container body 21 . 3 and 4 , the holding frame 223 has a flat plate shape and is disposed on the dielectric plate 222 so as to be substantially parallel to the surface of the substrate W provided in the processing chamber 1 . Specifically, the holding frame 223 is arranged so that the lower surface thereof contacts the upper surfaces of the dielectric plate 222 and the metal plate 221 . The holding frame 223 is detachably attached to the upper surface 21b of the container body 21 by a fixing member (not shown) such as a screw mechanism.

The material constituting the holding frame 223 is, for example, one selected from the group consisting of Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co. of metals or alloys thereof.

A plurality of openings 223o in the shape of a long hole penetrating in the thickness direction are formed in the holding frame 223, and the dielectric plate 222 is exposed through the openings 223o. As shown in Fig. 4, the opening 223o is formed at a position corresponding to each antenna 3 (specifically, each conductor element 31). More specifically, the opening 223o is formed so as to surround each antenna 3 and the magnetic field transmission window 5 at a position corresponding thereto when viewed from the thickness direction. Here, nine openings 223o are formed so as to correspond to three antennas 3 (that is, nine conductor elements 31).

The plasma processing apparatus 100 of the present embodiment may include a holding frame cooling mechanism (not shown) that cools the holding frame 223 . The holding frame cooling mechanism may cool the holding frame 223 by means of water cooling or air cooling, for example. In the case of water cooling, the holding frame 223 may be configured to be cooled by having a hollow structure having a flow path through which the cooling liquid can flow therein. Moreover, in the case of air cooling, you may comprise so that the holding frame 223 may be cooled by ventilation by a fan etc.

<Effect of this embodiment>

According to the plasma processing apparatus 100 of the present embodiment configured in this way, since a part of the window member 22 forming the magnetic field transmission window 5 is made of a metal material having greater toughness than a dielectric material such as ceramics, the dielectric material The thickness of the magnetic field transmission window 5 can be made small compared with the case of configuring the magnetic field transmission window 5 only by using only the magnetic field transmission window 5 . Thereby, the distance from the antenna 3 to the processing chamber 1 can be shortened, and the high-frequency magnetic field generated from the antenna 3 can be efficiently supplied into the processing chamber 1 .

In addition, since the metal plate 221 is provided to block the opening 211 of the container body 21 , all members surrounding the processing chamber 1 serving as the plasma generating space can be electrically grounded. Thereby, the influence on the plasma by the voltage of the antenna 3 can be reduced, and it is possible to reduce the electron temperature and reduce the ion energy.

<Other modified embodiments>

In addition, this invention is not limited to the said embodiment.

Although the metal plate 221 was flat in the said embodiment, it is not limited to this. In another embodiment, as shown in FIG. 7, it may be comprised so that the surface on which the dielectric plate 222 is put may be located rather than the upper wall 21a of the container body 21 on the board|substrate W side. With such a configuration, since the antenna 3 can be brought closer to the processing chamber 1 , the plasma density formed in the processing chamber 1 can be further improved.

In the above embodiment, the angle θ _s between the slit 221s and the antenna 3 was about 90°, but it is not limited thereto. In another embodiment, the _{angle θ s} may be _{any angle θ s} of about 30° or greater and about 90° or less. The angle θ _s is more preferably about 60° or more and about 90° or less, and most preferably about 90°.

In another embodiment, as shown in Fig. 8, _{in addition to the slits 221s having an angle θ s} formed with the antenna 3 of about 30° or more and about 90° or less, the angle formed with the antenna 3 is about 0° or more. , a slit 221t of less than about 30° may be further formed in the metal plate 221 . In this case, the angle between the slit 221t and the antenna 3 is preferably 0°. In addition, it is preferable that the slit 221t is formed so as to be positioned directly under the antenna 3 .

Although the slits 221s were formed so that it might become mutually parallel in the said embodiment, it is not limited to this. The slits 221s may be formed so that the angles formed by the antenna 3 are different from each other. Further, the slit (221s) is not necessarily formed at a constant pitch length d _p. For example, in the vicinity of the central position in the longitudinal direction of the antenna 3 (specifically, the conductor element 31 ), the pitch length d _p is increased to be closer to the end of the antenna 3 in the longitudinal direction. the quality may decrease the pitch length d _p.

In the above embodiment, only one second flow passage portion 91y is formed between the adjacent slits 221s. In addition, the flow path 91 is not limited to being formed without branching from one opening 91a to the other opening 91b, You may form so that it may branch in the middle. In addition, the openings 91a and 91b do not need to be provided at both ends of the flow path 91 , and may be provided in the middle of the flow path 91 .

Although the plasma processing apparatus of the said embodiment was provided with the metal plate 221 of 1 sheet, it is not limited to this. In another embodiment, you may provide the metal plate 221 of multiple sheets which overlapped in the thickness direction. In this case, each metal plate 221 may be mutually different from each other, and the same constituent material may be sufficient as it.

Although the window member 22 was attached to the upper surface 21b of the container body 21 in the said embodiment, it is not limited to this. In another embodiment, it may be attached to a flange provided on the upper surface of the container body 21 .

In the above embodiment, a plurality of openings 223o of the holding frame 223 are formed at positions corresponding to the respective conductor elements 31, but the present invention is not limited thereto. In another embodiment, when viewed from the thickness direction, one opening may be formed so as to surround all the conductor elements 31 .

Although the plasma processing apparatus 100 of the said embodiment was equipped with the plurality of antennas 3, it is not limited to this, You may be equipped with only one antenna 3. As shown in FIG.

In the plasma processing apparatus 100 of the above embodiment, the antenna 3 is provided with a plurality of conductor elements 31 and a capacitor 32 which is a quantitative element electrically connected in series with the conductor elements 31 adjacent to each other. It is not limited to this. In another embodiment, the antenna 3 includes only one conductor element 31 , and does not need to include the capacitor 32 .

In the plasma processing apparatus 100 of another embodiment, as shown in FIG. 9, the opening is formed in the side surface 2211 of the metal plate 221, The side plate 92 may be pinched|interposed so that this opening may be closed. In addition, a part of the inner wall of the flow path 91 (here, the 1st flow path part 91x) may be formed by the side surface 921 of a side plate. The flow path 91 is, for example, cut along the longitudinal direction of the slit from the side surface 2211 of the metal plate 221 to form the second flow path portion 91y, and is cut along the direction orthogonal to the longitudinal direction of the slit. It can be formed by forming the 1st flow path part 91x by doing this, and providing the side plate 92 so that the opening formed in the side surface 2211 by the said cutting process may be closed. Naturally, the flow path 91 may be formed by another method.

Although the antenna 3 was a linear conductor in the above embodiment, the present invention is not limited thereto, and a spiral conductor or a dome-shaped coil may be used.

In addition, this invention is not limited to the said embodiment, It cannot be overemphasized that various deformation|transformation is possible in the range which does not deviate from the meaning.

<Evaluation of high frequency magnetic field strength>

The effect of the high frequency magnetic field due to the difference in the specifications of the metal plate 221 in the plasma processing apparatus 100 (slit length d _s , slit angle θ _s , slit width d _{w , plate thickness, etc.)} was evaluated by In addition, this invention is not limited by the following experimental examples, It is also possible to add and implement a change in the range suitable for the meaning of the above and later description, and they are all included in the technical scope of this invention.

(1) Effect of _{slit length d s}

The influence on the high frequency magnetic field by the length d _{s between slits was evaluated.} Specifically, six metal plates with a thickness of 10 µm made of stainless alloy (SUS316) were prepared. In each metal plate, a slit having a width of 0.5 mm was formed _{so that the length d s} between the slits was different (0 mm, 5 mm, 15 mm, 45 mm, 70 mm, 140 mm, respectively). In addition, all of the slits formed in each metal plate were made so that the _{angle (theta)s formed with the antenna to be set later became 90 degrees.} Then, a high-frequency magnetic field was supplied to each metal plate from an antenna provided on one surface side, and the parallel magnetic field strength of the high-frequency magnetic field transmitted to the opposite surface side (processing chamber side) was measured using a pick-up coil of one turn. Here, 150W of high-frequency power (frequency: 13.56 MHz) was supplied to the antenna to generate a high-frequency magnetic field. And the ratio (magnetic field intensity ratio) of the parallel magnetic field intensity in each metal plate with respect to the parallel magnetic field intensity in the metal plate whose length between slits is 0 mm was computed. The results are shown in FIG. 10 .

From the results shown in Fig. 10, it was confirmed that the shorter the length between the slits, the more efficiently the high-frequency magnetic field generated from the antenna can be supplied to the processing chamber side. In particular, it was confirmed that the parallel magnetic field strength became stronger by setting the length between the slits to be about 15 mm or less, and it was further strengthened by setting the length between the slits to be about 5 mm or less.

(2) Effect of _{slit angle θ s}

The influence on the high frequency magnetic field by the angle θ _{s of the slit was evaluated.} Specifically, four metal plates with a thickness of 10 µm made of stainless alloy (SUS316) were prepared. In each metal plate, slits with a constant width dimension (0.5 mm) were formed in parallel with a constant pitch length (5 mm). Here, a slit formed in each metal plate has an angle to the antenna and to set θ _s (the angle θ _s of the slit) is different after each (90 °, 60 °, 45 °, 30 ° , respectively). And the parallel magnetic field intensity|strength in the processing chamber side of each metal plate was measured in the same procedure as said (1). Then, the ratio (magnetic field strength ratio) of the parallel magnetic field intensity in each metal plate to the parallel magnetic field intensity in the metal plate in which the slit _{angle θ s is 90° (that is, the slit is orthogonal to the antenna) was calculated.} . The results are shown in FIG. 11 .

From the results shown in Fig. 11, it was confirmed that the high-frequency magnetic field generated from the antenna can be efficiently supplied to the processing chamber _{side at any slit angle θ s of 30° to 90°.} And it was confirmed that the higher the angle θ _s of the slit, that is, the closer it is to a right angle with respect to the antenna, the more efficiently the high-frequency magnetic field can be supplied. In particular, _{it was confirmed that the parallel magnetic field strength became stronger by setting the angle θ s} of the slit to be about 45° or more, and it was further strengthened by setting it to about 60° or more.

(3) Effect of _{slit width d w}

By the slit width d _w to evaluate the influence of the high frequency magnetic field. Specifically, three metal plates (Cu) having a thickness of 1 mm were prepared. In each metal plate, slits of different width dimensions (1 mm, 3 mm, 5 mm) were formed with a predetermined length between the slits (5 mm). That is, the pitch lengths of the slits in each metal plate were set to 6 mm, 8 mm, and 10 mm, respectively. In addition, the slits formed in each metal plate were such that the angle θ _s formed with the antenna to be set later was 90°. And the parallel magnetic field intensity|strength in the processing chamber side of each metal plate was measured in the same procedure as said (1). Further, a metal plate having a slit pitch of 0 mm (that is, the slits are formed so as to be continuous and are completely open) was prepared, and the parallel magnetic field strength was measured in the same procedure. The ratio (magnetic field intensity ratio) of the parallel magnetic field intensity|strength in each metal plate with respect to the parallel magnetic field intensity|strength in the metal plate whose slit pitch is 0 mm was computed. The results are shown in FIG. 12 .

From the results shown in Fig. 12, it was confirmed that the high-frequency magnetic field generated from the antenna can be efficiently supplied to the processing chamber side with any slit width of 1 mm to 5 mm. And it was confirmed that the higher the slit width, the more efficiently the high-frequency magnetic field can be supplied.

(4) Influence by the thickness of the metal plate

The influence on the high frequency magnetic field by the thickness of a metal plate was evaluated. Specifically, a metal plate (Cu) having a thickness of 1 mm and a metal plate (Cu) having a thickness of 3 mm were prepared. In each metal plate, a slit having a width of 3 mm was formed at a pitch of 8 mm. In addition, all slits formed in each metal plate were made so that the _{angle (theta)s formed with the antenna to be set later became 90 degrees.} And the parallel magnetic field intensity|strength in the processing chamber side of each metal plate was measured in the same procedure as said (1). Here, the parallel magnetic field strength was measured by varying the high-frequency power supplied to the antenna by 50 W from 100 W to 300 W. Then, the ratio (magnetic field strength ratio) of the parallel magnetic field intensity in the 3 mm thick metal plate to the parallel magnetic field intensity in the 1 mm thick metal plate was calculated for each magnitude of the supplied high-frequency power. The results are shown in FIG. 13 .

From the results shown in Fig. 13, regardless of the magnitude of the high-frequency power supplied to the antenna, the parallel magnetic field strength in the 1 mm-thick metal plate was greater than the parallel magnetic field strength in the 3-mm-thick metal plate. As a result, it was confirmed that the smaller the thickness of the metal plate, the more efficient the high-frequency magnetic field generated from the antenna could be supplied to the processing chamber side.

Industrial Applicability

According to the present invention, in the plasma processing apparatus in which the antenna is disposed outside the processing chamber, the high-frequency magnetic field generated from the antenna can be efficiently supplied to the processing chamber.

100 … plasma processing device
One … processing room
21 … container body
211 … opening
221 … plate
221s … slit
222 … dielectric plate
3 … antenna
4 … high frequency power
5 … magnetic field transmission window

Claims (12)

A plasma processing apparatus for vacuum processing an object disposed in a processing chamber using plasma, the plasma processing apparatus comprising:
a container body having an opening in a wall forming the processing chamber;
a metal plate installed to close the opening and having a slit penetrating in the thickness direction;
a dielectric plate blocking the slit of the metal plate from the outside of the processing chamber;
and an antenna installed outside the processing chamber to face the metal plate and connected to a high-frequency power source to generate a high-frequency magnetic field. The method of claim 1,
The plasma processing apparatus is formed so that the slit is positioned between the antenna and the processing chamber when viewed from the thickness direction. 3. The method according to claim 1 or 2,
The antenna is in a straight shape,
A plasma processing apparatus in which a plurality of the slits are formed parallel to each other. 4. The method according to any one of claims 1 to 3,
A plasma processing apparatus in which a flow path through which a cooling fluid can flow is formed inside the metal plate. 5. The method of claim 4 citing claim 3,
The plasma processing apparatus is formed such that the flow path passes at least between adjacent slits. 6. The method according to any one of claims 1 to 5,
a window member attached to the container body to block the opening and forming a magnetic field transmission window through which the high-frequency magnetic field generated from the antenna is transmitted into the processing chamber;
A plasma processing apparatus in which the window member includes the metal plate, the dielectric plate, and a holding frame for holding the metal plate and the dielectric plate. 7. The method according to any one of claims 1 to 6,
An angle formed between the slit and the antenna when viewed from the thickness direction is 30° or more and 90° or less. 8. The method of claim 7,
An angle between the slit and the antenna is 45° or more and 90° or less. 9. The method according to any one of claims 1 to 8,
A plasma processing apparatus in which a width of the slit is equal to or less than a thickness of the metal plate. 10. The method of claim 9,
A plasma processing apparatus in which a width of the slit is 1/2 or less of a thickness of the metal plate. 11. The method according to any one of claims 4 to 10, which refers to claim 3 or claim 3,
The plasma processing apparatus of which the width dimension of the said metal plate between mutually adjacent slits is 15 mm or less. 12. The method of claim 11,
A plasma processing apparatus in which the width of the metal plate between adjacent slits is 5 mm or less.

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