TWI806253B - Plasma treatment device - Google Patents

Abstract

In order to finely adjust the plasma density distribution along the long side direction of the antenna, and realize further uniformity of the plasma density distribution, the plasma processing device of the present invention includes: a vacuum container 1; an antenna 2, which is arranged in the vacuum container 1 and the high-frequency window 9 blocks the opening 1x formed in the position of the vacuum vessel 1 facing the antenna 2, and the antenna 2 includes outgoing conductors 21 whose flow directions of the high-frequency current IR are opposite to each other. and the return conductor 22 , the plasma processing apparatus further includes a distance adjustment mechanism 10 , and the distance adjustment mechanism 10 locally adjusts the relative distance between the outward conductor 21 and the return conductor 22 .

Description

Plasma treatment device

The invention relates to a plasma treatment device.

As a conventional plasma processing apparatus, as shown in Patent Document 1, there is one in which an antenna through which a high-frequency current flows is constituted by a conductor that becomes an outgoing path of high-frequency current and a conductor that turns back from the outgoing path to become a return path of high-frequency current.

As mentioned above, by using the round-trip conductor formed by turning the antenna back halfway, the high-frequency currents flowing in the outgoing path and the return path are opposite to each other, so the magnetic field generated by the high-frequency current flowing in the outgoing path and the The magnetic fields generated by the high-frequency current flowing in the return path cancel each other out.

Therefore, in the plasma processing apparatus shown in Patent Document 1, the distance between the round-trip conductors at both ends of the antenna is made larger than the distance between the round-trip conductors at the center, and the distance between the round-trip conductors at both ends is smaller than that at the center of the antenna. The effective impedance is relatively large. Thereby, compared with the center part of the antenna, the magnetic field energy supplied to the plasma from both ends is relatively larger, and the plasma density distribution along the longitudinal direction of the antenna is uniformized.

However, in the above configuration, although the plasma density distribution along the longitudinal direction of the antenna can be substantially uniformed, it is difficult to finely adjust it locally.

[Prior art literature]

[Patent Document]

Patent Document 1: Japanese Patent No. 4844697

Therefore, the invention of the present application was made to solve the above-mentioned problems, and its main subject is to finely adjust the plasma density distribution along the longitudinal direction of the antenna to achieve further uniformity of the plasma density distribution.

That is, the plasma processing apparatus of the present invention is characterized by comprising: a vacuum vessel; an antenna provided outside the vacuum vessel through which a high-frequency current flows; and a high-frequency window formed on a side of the vacuum vessel facing the antenna. The opening at the position is blocked, the antenna includes an outgoing conductor and a return conductor whose flow directions of high-frequency current are opposite to each other, and the plasma processing device further includes a distance adjustment mechanism, and the distance adjustment mechanism controls the outgoing conductor and the return conductor. The relative distance of the return conductors is locally adjusted.

According to the plasma processing apparatus configured as described above, the distance adjustment mechanism locally adjusts the relative distance between the outgoing conductor and the return conductor, so that the plasma density distribution along the long side direction of the antenna can be finely adjusted, and the electric current can be realized. Further homogenization of pulp density distribution.

Assuming that no return conductor is provided, and the high-frequency current flowing in the outgoing conductor is intended to return to the power supply through a structure at ground potential such as a vacuum vessel, the high-frequency current flowing in the return path will only generate power loss due to heat generation , cannot be effectively used for plasma generation.

Therefore, in order to effectively utilize the high-frequency current flowing through the return conductor, it is preferable to The distance adjustment mechanism adjusts the position of the return conductor.

Thereby, the plasma density distribution can be adjusted by the high-frequency current flowing through the return conductor, so the high-frequency current flowing through the return conductor can be effectively used for plasma generation.

In order to further finely adjust the plasma density distribution along the longitudinal direction of the antenna, it is preferable that the distance adjustment mechanism adjusts the positions of a plurality of positions of the return conductor.

Preferably, the outgoing conductor is disposed closer to the vacuum vessel than the return conductor.

Thereby, the distance from the outgoing conductor to the inside of the vacuum container can be shortened, and the high-frequency magnetic field generated from the outgoing conductor can be efficiently supplied into the vacuum container.

Preferably, the method further includes: a dielectric tube covering the return conductor; and a positioning member disposed in the dielectric tube to position the return conductor in the dielectric tube.

Thereby, the dielectric tube can be easily deformed by an external force, so local adjustment of the plasma density distribution can be easily performed.

In addition, since the return conductor is positioned in the dielectric tube by the positioning member, the relative distance between the outgoing conductor and the return conductor can be further adjusted with good precision, and further finely adjusted the electrical distance along the long side direction of the antenna. Pulp density distribution.

There is a concern that the dielectric tube may be damaged by heat generated by the high-frequency current flowing through the return conductor.

Therefore, it is preferable to flow cooling water in the dielectric tube.

Thereby, the simplification of the distance adjustment using the dielectric tube can be ensured, and the The cooling function of the dielectric tube.

As a more specific embodiment, a form in which the positioning members are provided at a plurality of places in the dielectric tube, and each of the positioning members includes a flow hole through which the cooling water flows may be mentioned.

In order to improve the cooling effect of the cooling water, preferably, the cooling water flows meanderingly in the dielectric tube.

According to the present invention constituted as described above, the plasma density distribution along the longitudinal direction of the antenna can be finely adjusted, and further uniformity of the plasma density distribution can be achieved.

1: Vacuum container

1a: upper wall

1x: opening

2: Antenna

2a: Power supply terminal

2b: terminal part

3: High frequency power supply

4: Vacuum exhaust device

5: Substrate holder

6: Bias power supply

7: Slit plate

7x: Slit

8: Dielectric board

9: High frequency window

10: Distance adjustment mechanism

10P: Gas inlet port

11: Grip

21: outgoing conductor

22: Return conductor

23: Dielectric tube

24: Positioning components

24L: Flow hole

24H: Through hole

25: The second positioning member

31: integrated circuit

51: heater

100: Plasma treatment device

200: plasma source

CL: cooling water

G: gas

IR: high frequency current

P: inductively coupled plasma

W: Substrate

FIG. 1 is a longitudinal sectional view schematically showing the structure of a plasma processing apparatus according to a first embodiment.

Fig. 2 is a cross-sectional view schematically showing the structure of the plasma processing apparatus according to the first embodiment.

Fig. 3 is a schematic diagram showing the configuration of a distance adjusting mechanism in the first embodiment.

Fig. 4 is a schematic diagram showing the structure of a return conductor in the second embodiment.

Fig. 5 is a schematic diagram showing the structure of a positioning member in the second embodiment.

Fig. 6 is a schematic diagram showing the structure of a positioning member in the second embodiment.

[First Embodiment]

Hereinafter, an embodiment of the plasma processing apparatus of the present invention will be described with reference to the drawings.

<device structure>

The plasma processing apparatus 100 of this embodiment processes the substrate W using the inductively coupled plasma P. Here, the substrate W is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic electroluminescent (EL) display, a flexible substrate for a flexible display, or the like. Further, the processing performed on the substrate W is, for example, film formation by a plasma chemical vapor deposition (Chemical Vapor Deposition, CVD) method, etching, ashing, sputtering, and the like.

In addition, this plasma processing apparatus 100 is also called a plasma CVD apparatus when performing film formation by a plasma CVD method, is also called a plasma etching apparatus when performing etching, and is also called a plasma etching apparatus when performing ashing. It is also called a plasma ashing device, and it is also called a sputtering device in the case of sputtering.

Specifically, as shown in FIG. 1 and FIG. 2 , the plasma processing device 100 includes: a vacuum container 1, which is evacuated and introduced into gas G; and a plasma source 200, which generates plasma in the vacuum container 1 , The plasma source 200 includes an antenna 2 provided outside the vacuum vessel 1 , and a high-frequency power supply 3 for applying a high frequency to the antenna 2 . In the above structure, by applying a high frequency from the high frequency power supply 3 to the antenna 2, a high frequency current IR is passed through the antenna 2 to generate an induced electric field in the vacuum vessel 1, thereby generating inductively coupled plasma P.

The vacuum container 1 is, for example, a container made of metal, and on its wall (here, the upper wall) In 1a), an opening 1x penetrating in the thickness direction is formed. Here, the vacuum container 1 is electrically grounded, and its interior is vacuum-exhausted by a vacuum exhaust device 4 .

In addition, the gas G is introduced into the vacuum container 1 through, for example, one or more gas introduction ports 10P provided in a flow regulator (not shown) or the vacuum container 1 . The gas G may be a gas corresponding to the content of the process to be performed on the substrate W. As shown in FIG. For example, when forming a film on a substrate by a plasma CVD method, the gas G is a source gas or a gas obtained by diluting it with a diluent gas (for example, H ₂ ). If further specific examples are given, when the source gas is SiH ₄ , an Si film can be formed on the substrate, when it is SiH ₄ +NH ₃ , a SiN film can be formed on the substrate, and when it is SiH ₄ +O In the case of ₂ , a SiO ₂ film can be formed on the substrate, and in the case of SiF ₄ +N ₂ , a SiN:F film (silicon fluoride nitride film) can be formed on the substrate.

A substrate holder 5 for holding a substrate W is provided inside the vacuum container 1 . As in the above example, a bias voltage may be applied to the substrate holder 5 from the bias power supply 6 . The bias voltage is, for example, a negative DC voltage, a negative bias voltage, etc., but is not limited thereto. With such a bias voltage, for example, the energy when positive ions in the plasma P are incident on the substrate W can be controlled, and the crystallinity of a film formed on the surface of the substrate W can be controlled, for example. A heater 51 for heating the substrate W may be provided in advance in the substrate holder 5 .

As shown in FIGS. 1 and 2 , the antenna 2 is arranged to face the opening 1 x formed in the vacuum container 1 . Furthermore, the number of antennas 2 is not limited to one, and multiple antennas 2 may also be provided.

As shown in FIG. 2, the power supply end 2a as one end of the antenna 2 is connected to the high-frequency power supply 3 via an integrated circuit 31, and the terminal 2b as the other end is directly connected to the power supply 3. land. Furthermore, the terminal portion 2b may be grounded via a capacitor, a coil, or the like.

The high-frequency power supply 3 can flow a high-frequency current IR through the antenna 2 through the integrated circuit 31 . The frequency of the high frequency is, for example, a usual 13.56 MHz, but it is not limited thereto and can be changed appropriately.

Here, the plasma source 200 of the present embodiment further includes: a slit plate 7 for closing the opening 1x formed on the wall (upper wall 1a) of the vacuum vessel 1 from the outside of the vacuum vessel 1; The outside of the vacuum container 1 closes the slit 7x formed in the slit plate 7 .

The slit plate 7 is formed with a slit 7x penetrating along its thickness direction, so that the high-frequency magnetic field generated by the antenna 2 can pass through the vacuum vessel 1, and prevent the electric field from entering the vacuum vessel 1 from the outside of the vacuum vessel 1. .

Specifically, as shown in FIG. 3 , the slit plate 7 is in the form of a flat plate formed with a plurality of slits 7x parallel to each other, preferably with a higher mechanical strength than the dielectric plate described below, and Preferably the thickness dimension is larger than the dielectric plate.

If described more specifically, the slit plate 7 is made by, for example, being selected from the group including Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W or Co A metal or its alloy (such as stainless steel alloy, aluminum alloy, etc.) and other metal materials are manufactured by rolling (such as cold rolling or hot rolling), for example, the thickness is about 5mm. However, the manufacturing method and thickness are not limited thereto, and can be appropriately changed according to the specifications.

The dielectric plate 8 is provided on the outward surface of the slit plate 7 (the back of the inward surface facing the inside of the vacuum container 1 ), and closes the slits of the slit plate.

The dielectric plate 8 as a whole contains a dielectric substance, which is in the shape of a flat plate, such as containing oxide Ceramics such as aluminum, silicon carbide, and silicon nitride, inorganic materials such as quartz glass and alkali-free glass, resin materials such as fluororesin (such as Teflon), etc. Furthermore, from the viewpoint of reducing dielectric loss, the material constituting the dielectric plate 8 is preferably a dielectric loss factor of 0.01 or less, more preferably 0.005 or less.

Here, the thickness of the dielectric plate 8 is made smaller than the thickness of the slit plate 7, but it is not limited to this. For example, in the state where the vacuum container 1 is evacuated, there is a vacuum container that can withstand the impact from the slit 7x. The strength of the differential pressure between the inside and outside of 1 is sufficient, and can be appropriately set according to specifications such as the number and length of the slits 7x. However, it is preferably thinner from the viewpoint of shortening the distance between the antenna 2 and the vacuum container 1 .

With the above configuration, the slit plate 7 and the dielectric plate 8 function as a high-frequency window (magnetic field transmission window) 9 through which a magnetic field passes. That is, when a high frequency is applied to the antenna 2 from the high frequency power supply 3, the high frequency magnetic field generated by the antenna 2 is formed (supplied) in the vacuum container 1 through the high frequency window 9 including the slit plate 7 and the dielectric plate 8. . Thereby, an induced electric field is generated in the space in the vacuum container 1, and the inductive coupling type plasma P is generated.

And, in this embodiment, as shown in FIGS. 1 to 3 , the antenna 2 includes an outgoing conductor 21 and a return conductor 22 whose flow directions of the high-frequency current IR are opposite to each other. As shown in FIG. 3 , the plasma processing apparatus 100 further includes a distance adjustment mechanism 10 for locally adjusting the relative distance between the outward conductor 21 and the return conductor 22 .

First, the outgoing conductor 21 and the return conductor 22 will be described.

The outgoing conductor 21 and the return conductor 22 of this embodiment are electrically connected to each other, and are connected to a common high-frequency power supply 3 . Specifically, the outgoing conductor 21 includes the above-mentioned power supply end 2a connected to the high-frequency power supply 3 via the integrated circuit 31, and the return conductor 22 includes a direct The above-mentioned terminal portion 2b connected to the ground.

In this embodiment, the outgoing conductor 21 and the return conductor 22 are arranged separately along the vertical direction, that is, the direction perpendicular to the opening 1x of the vacuum container 1, and here, the outgoing conductor 21 is arranged closer to the vacuum container than the return conductor 22. 1 opening 1x position.

The outgoing conductor 21 extends parallel to the opening 1x of the vacuum container 1 and is a tubular conductor here. Further, the return conductor 22 is arranged so as to flow a high-frequency current IR opposite to that of the outward conductor 21 , and is a tubular conductor here.

Next, the distance adjustment mechanism 10 will be described.

The distance adjustment mechanism 10 locally adjusts the separation distance between the outgoing conductor 21 and the return conductor 22 along the separation direction, that is, here, the separation distance between the outgoing conductor 21 and the return conductor 22 along the vertical direction.

The distance adjustment mechanism 10 of the present embodiment can adjust the above-mentioned separation distance locally by adjusting the position of the return conductor 22. Specifically, it can adjust the position of one or more parts along the longitudinal direction of the return conductor 22. constituted in a manner.

If described more specifically, the distance adjustment mechanism 10 includes: a plurality of gripping parts 11, which grip a plurality of positions of the return conductor 22, so that it can advance and retreat relative to the outward conductor 21; The driving source makes the holding parts 11 move independently.

The plurality of holding parts 11 are insulators electrically insulated from the return conductor 22 , and can move along the vertical direction. As shown in FIG. 3 , one of the gripping portions 11 is disposed directly above the central portion of the opening 1x of the vacuum vessel 1 , and is opposite to the gripping portion. 11 and another holding portion 11 is provided at a symmetrical position along the longitudinal direction of the return conductor 22 . In addition, in the present embodiment, the plurality of grips 11 are arranged at equal intervals, and are all provided inside the opening 1x when viewed from a direction perpendicular to the opening 1x of the vacuum container 1 .

<Effect of the first embodiment>

According to the plasma processing apparatus 100 of the present embodiment configured as described above, since the distance adjustment mechanism 10 locally adjusts the relative distance between the outgoing conductor 21 and the return conductor 22, the electric current along the longitudinal direction of the antenna 2 can be adjusted. The plasma density distribution is finely adjusted to achieve further uniformity of the plasma density distribution.

Moreover, since the distance adjustment mechanism 10 adjusts the position of the return conductor 22, the plasma density distribution can be adjusted by the high-frequency current IR flowing in the return conductor 22, and the plasma density distribution can be circulated in the return conductor 22. The high frequency current IR is effectively used for plasma generation.

Furthermore, since the distance adjustment mechanism 10 adjusts the positions of a plurality of positions of the return conductor 22, the plasma density distribution along the longitudinal direction of the antenna 2 can be further finely adjusted.

In addition, since the outward conductor 21 is arranged at a position closer to the vacuum vessel 1 than the return conductor 22, the distance from the outward conductor 21 to the inside of the vacuum vessel 1 can be shortened, so that the high-frequency magnetic field generated by the outward conductor 21 can be efficiently used. It is supplied into the vacuum container 1.

[Second Embodiment]

Next, the second embodiment of the plasma treatment device of the present invention will be described with reference to the drawings. line description.

In this embodiment, the structure of the return conductor 22 and its surroundings is different from that of the first embodiment, so the difference will be described.

As shown in FIG. 4, the return conductor 22 of this embodiment is arrange|positioned so that the high-frequency current IR reversed to the outward conductor 21 may flow, and it is a linear conductor here.

Furthermore, as shown in FIG. 4 , the return conductor 22 is covered with a dielectric tube 23 .

The dielectric tube 23 includes a flexible dielectric body, specifically, a tube made of Teflon, nylon, or the like, for example.

As shown in FIGS. 5 and 6 , a positioning member 24 for positioning the return conductor 22 in the dielectric tube 23 is provided inside the dielectric tube 23 .

The positioning member 24 comprises a dielectric body, here positioning the return conductor 22 on the central axis of the dielectric tube 23 . Specifically, the positioning member 24 is a columnar shape fitted into the dielectric tube 23 without shaking, and a through hole 24H through which the return conductor 22 passes is formed at the center thereof.

Moreover, as shown in FIG. 5 , a second positioning member 25 for positioning the return conductor 22 within the dielectric tube 23 is provided inside the dielectric tube 23 . The second positioning member 25 includes a dielectric body, and positions the return conductor 22 on the central axis of the dielectric tube 23 . Specifically, the second positioning member 25 is elongated and extends along the central axis of the dielectric tube, and a through hole through which the return conductor 22 passes is formed at the center.

In the present embodiment, the cooling water CL is configured to flow through the dielectric tube 23 . Specifically, as shown in FIG. 5 , in the dielectric tube 23 along the axial direction Positioning members 24 are provided at a plurality of locations, and each positioning member 24 includes a flow hole 24L through which the cooling water CL flows.

More specifically, as shown in FIG. 6 , each positioning member 24 includes a plurality of flow holes 24L, and these flow holes 24L are arranged at equal intervals along the circumferential direction, for example. In addition, when viewed from the axial direction of the dielectric tube 23 , the flow holes 24L of the positioning members 24 adjacent to each other do not overlap, and are arranged in a shifted manner along the circumferential direction here. Thereby, the cooling water CL meanders and flows in the dielectric tube 23 .

<Effect of the second embodiment>

According to the plasma processing apparatus 100 of the present embodiment constituted as described above, since the return conductor 22 is made into a linear shape, and the return conductor 22 is covered by the dielectric tube 23, it can be easily used by an external force. The return conductor 22 or the dielectric tube 23 deforms, and local adjustment of the plasma density distribution can be easily performed.

Moreover, since the return conductor 22 is positioned in the dielectric tube 23 by the positioning member 24, the relative distance between the outward conductor 21 and the return conductor 22 can be further adjusted with good precision, and further finely adjusted along the antenna. 2 Plasma density distribution in the long-side direction.

Furthermore, since the cooling water CL meanders in the dielectric tube 23, the distance adjustment by the dielectric tube 23 can be simplified and the cooling function of the dielectric tube 23 can be exhibited.

[Other modified embodiments]

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

For example, in the above embodiment, the outgoing conductor 21 and the return conductor The case where the body 22 is electrically connected has been described, but these do not need to be electrically connected. As long as the high-frequency current IR flows in reverse to each other, for example, the outgoing conductor 21 and the return conductor 22 can also be connected to different high-frequency currents. power supply3.

Furthermore, the distance adjustment mechanism 10 of the above-described embodiment adjusts the position of the return conductor 22 , but it may also adjust the position of the outward conductor 21 .

In addition, in the above-mentioned embodiment, the outgoing conductor 21 and the return conductor 22 are separated in the vertical direction, but they may be separated in a direction parallel to the opening 1x of the vacuum vessel 1, for example.

In addition, this invention is not limited to the said embodiment, Of course, a various deformation|transformation is possible in the range which does not deviate from the summary.

[industrial availability]

According to the present invention, the plasma density distribution along the long side direction of the antenna can be finely adjusted to achieve further uniformity of the plasma density distribution.

1x: opening

2: Antenna

7: Slit plate

7x: Slit

8: Dielectric board

9: High frequency window

10: Distance adjustment mechanism

11: Grip

21: outgoing conductor

22: Return conductor

IR: high frequency current

Claims (8)

A plasma processing apparatus comprising: a vacuum container; an antenna provided outside the vacuum container through which a high-frequency current flows; and a high-frequency window blocking an opening formed in a position facing the antenna of the vacuum container, In addition, the antenna includes an outgoing conductor and a return conductor whose flow directions of high-frequency current are opposite to each other, and the plasma processing device further includes a distance adjustment mechanism, and the distance adjustment mechanism has a corresponding distance between the outgoing conductor and the return conductor. The relative distance is adjusted locally. The plasma processing device according to claim 1, wherein the distance adjustment mechanism adjusts the position of the return conductor. The plasma processing device according to claim 2, wherein the distance adjustment mechanism adjusts the positions of multiple positions of the return conductor. The plasma processing apparatus according to any one of claim 1 to claim 3, wherein the outgoing conductor is disposed closer to the vacuum container than the return conductor. The plasma processing device according to any one of claim 1 to claim 3, further comprising: a dielectric tube covering the return conductor; and The positioning member is arranged in the dielectric tube to position the return conductor in the dielectric tube. The plasma processing device according to claim 5, wherein cooling water flows in the dielectric tube. The plasma processing device according to claim 6, wherein the positioning members are arranged at multiple positions in the dielectric tube, and each positioning member includes a flow hole through which the cooling water flows. The plasma processing device as claimed in claim 7, wherein the cooling water flows meanderingly in the dielectric tube.

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