KR20210111601A - A plasma apparatus having the multiple matching coils - Google Patents

Abstract

The present invention relates to a plasma processing apparatus having multiple matching coils, which is installed in a vacuum chamber or a vacuum pipe line used in semiconductor/display manufacturing equipment to generate plasma so as to perform periodic cleaning of the chamber or remove a perfluoro compound (PFC), an unreacted gas, and a harmful gas, which are discharged from the chamber. According to the present invention, the plasma processing apparatus having the multiple matching coils includes: a discharge space part installed in an exhaust line of a vacuum chamber, and configured to generate plasma in an inner space to process a gas moving in the inner space; a gas introduction chamber installed in an upper portion of the discharge space part to connect the exhaust line to the discharge space part, and configured to introduce the gas discharged through the exhaust line into the discharge space part; a gas discharge chamber installed in a lower portion of the discharge space part to connect the exhaust line to the discharge space part, and configured to discharge the gas that has passed through the discharge space part to the exhaust line; a ferrite core unit surrounding an outside of the discharge space part; an electric field induction unit wound around the ferrite core unit; a power supply unit for applying an AC power to the electric field induction unit; and a matching coil unit configured as at least one coil wound around the gas introduction chamber or the gas discharge chamber, and configured to match the AC power supplied from the power supply unit to the electric field induction unit.

Description

Plasma processing device with multiple matching coils {A PLASMA APPARATUS HAVING THE MULTIPLE MATCHING COILS}

The present invention relates to a plasma processing apparatus having multiple matching coils, and more particularly, is installed in a vacuum chamber or a vacuum pipe line used in semiconductor and display manufacturing equipment to generate plasma to perform periodic cleaning of the chamber, or to It relates to a plasma processing apparatus having multiple matching coils capable of removing PFC, unreacted gas and harmful gas discharged from the apparatus.

A large part of the process of producing semiconductors, LCDs, OLEDs, etc. consists of a deposition process using a vacuum pump and an etching process, and the vacuum chamber used in these processes is periodically cleaned. .

This cleaning process is to remove by-products deposited in the vacuum chamber during the deposition process, and is mainly performed after depositing an oxide film, a nitride film, or a metal reaction film. When an oxide or nitride film is deposited, the chamber must be cleaned periodically. At this time, nitrogen trifluoride (NF3) or sulfur hexafluoride (SF6) is decomposed with a remote plasma device and introduced into the chamber to perform the cleaning process. .

Meanwhile, in the deposition process, an oxide film, a nitride film, or a metal film is deposited as described above. As the generation of semiconductors and display devices progresses, the range and usage of toxic gases and harmful precursors are increasing in order to improve performance. The precursor is mainly used for the deposition of a metal oxide film or a metal nitride film. Generally, a material such as zirconium (Zr), aluminum (Al), hafnium (Hf), or titanium (Ti) is used. Most of the precursors in liquid state have very strong reactivity, so when they are discharged in an unreacted state, they are accumulated in the exhaust pipe as a very harmful or dangerous by-product in itself.

Meanwhile, perfluorinated compound (PFCs) gases such as CF4, C3F8, and CHF3 are widely used in the etching process. When these gases are discharged in an unreacted state, they are powerful greenhouse gases and are very harmful to the global environment.

Therefore, as shown in FIG. 1 to treat such residual gas, a scrubber device 50 is also used, which has a problem of very low efficiency. In addition, in order to compensate for this, an attempt has been made to decompose these gases by disposing the plasma device 30 between the process chamber 10 and the vacuum pump 40 . As the plasma device 30 , a ferrite core plasma having a ferrite core 34 is used.

However, in this case, it is not possible to properly respond to different plasma characteristics for each equipment, and even for the same equipment, because of the continuous change in impedance according to different gas types, gas amounts, and pressure changes due to process characteristics, plasma is not properly generated. There is a problem that cannot be addressed.

The technical problem to be solved by the present invention is to provide a plasma apparatus having multiple matching coils, so that even if it is installed in semiconductors and equipment with different gas types and gas amounts, it is a single same device that can respond to various equipment environments as a vacuum pipe installation type plasma to provide the device.

Plasma processing apparatus having multiple matching coils according to the present invention for solving the above technical problem is installed in an exhaust line of a vacuum chamber, a discharge space for generating plasma in the internal space to process the gas moving in the internal space wealth; a gas inlet chamber installed in an upper portion of the discharge space by connecting the exhaust line and the discharge space, and configured to introduce a gas discharged through the exhaust line into the discharge space; a gas discharge chamber installed at a lower portion of the discharge space by connecting the exhaust line and the discharge space, and configured to discharge gas passing through the discharge space to the exhaust line; a ferrite core part installed to surround the outside of the discharge space part; an electric field induction part wound and installed in a structure surrounding the ferrite core part; a power supply unit for applying AC power to the electric field induction unit; and a matching coil unit installed with one or more coils wound in such a way as to surround the gas inlet chamber or the gas exhaust chamber, and matching the AC power supplied from the power supply unit to the electric field induction unit.

And in the present invention, it is preferable that the discharge space portion is made of an aluminum material and has a structure in which the gas flow is divided into two directions.

In addition, in the present invention, the matching coil unit may include: a first matching coil installed to surround the gas inlet chamber and configured to receive AC power from the power supply unit to perform primary matching; It is preferable to include a; a second matching coil installed to surround the gas discharge chamber and configured to receive AC power from the first matching coil to perform secondary matching.

In addition, in the present invention, the first matching coil may include a plurality of first coils surrounding the outside of the gas inlet chamber; It is preferable to include a first coil connection unit for connecting the plurality of first coils in parallel or in series.

In addition, the second matching coil in the present invention, a plurality of second coils surrounding the outside of the gas discharge chamber; It is preferable to include a second coil connection unit for connecting the plurality of second coils in parallel or in series.

In addition, in the present invention, the first coil or the second coil preferably has a size of 5 to 10 square.

In addition, in the present invention, the power supply unit preferably supplies power having a frequency of 100 to 500 kHz.

In addition, it is preferable that the plasma processing apparatus having multiple matching coils according to the present invention further includes a discharge pin which is installed so that an end thereof is exposed in the inner space of the discharge space and ignites the initial plasma.

In addition, in the present invention, it is preferable that the cross-sectional area of the distal end surface of the discharge pin is 0.5 cm ^{2 or less.}

In addition, in the present invention, it is preferable that a voltage of 15,000 ~ 20,000 V and a power of 100 mA or less is supplied to the discharge pin.

In addition, in the plasma processing apparatus having multiple matching coils according to the present invention, power is applied to the discharge pin when the plasma is ignited, and the power applied to the discharge pin is cut off after power is applied to the ferrite core part. It is preferable that the control unit is further provided.

According to the plasma processing apparatus having multiple matching coils according to the present invention, the impedance of AC power can be variously adjusted without a matching box by a combination of a series or parallel connection of the provided first matching coil and the second matching coil. can be transmitted effectively, and accordingly, there is an advantage in that it can respond to equipment of different processes and environments of different plasma impedances without replacing the device.

In addition, the plasma processing apparatus having multiple matching coils according to the present invention has the advantage of being able to respond to various kinds of process conditions.

1 is a block diagram showing an installation state of a conventional plasma processing apparatus for residual gas processing.
2 is a view showing an internal structure of a conventional plasma processing apparatus for residual gas processing.
3 is a perspective view illustrating a structure of a plasma processing apparatus according to an embodiment of the present invention.
4 is a front view showing the structure of a plasma processing apparatus according to an embodiment of the present invention.
5 is an exploded perspective view showing the structure of a plasma processing apparatus according to an embodiment of the present invention.
6 is a cross-sectional perspective view illustrating an internal structure of a plasma processing apparatus according to an embodiment of the present invention.
7 is a cross-sectional view illustrating an internal structure of a plasma processing apparatus according to an embodiment of the present invention.
8 is a perspective view showing the structure of a plasma processing apparatus according to another embodiment of the present invention.
9 is a front view showing the structure of a plasma processing apparatus according to another embodiment of the present invention.
10 and 11 are perspective views illustrating a structure of a discharge fin according to an embodiment of the present invention.
12 to 15 are views illustrating different connection methods of first and second matching coils according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 3 to 7 , the plasma processing apparatus 100 having multiple matching coils according to the present embodiment includes a discharge space unit 110 , a gas inlet chamber 120 , a gas discharge chamber 130 , and ferrite. It is configured to include a core unit 140 , an electric field induction unit 150 , a power supply unit 160 , and a matching coil unit 170 .

First, the discharge space part 110 is installed in the exhaust line 20 of the vacuum chamber 10, and is a component that generates plasma in the internal space to process the gas moving in the internal space. In this case, the discharge space 110 is made of an aluminum material, and as shown in FIGS. 6 and 7 , it is preferable that the gas flow is divided into two directions. Accordingly, two discharge spaces 111 and 112 divided into two branches are formed in the discharge space 110 , and an open space 113 is formed between the discharge spaces 111 and 112 .

Next, as shown in FIG. 3 , the gas inlet chamber 120 is installed by connecting the exhaust line 20 and the discharge space 110 to the upper portion of the discharge space 110 , and the exhaust It is a component for introducing the gas discharged through the line 20 into the discharge space 110 . Accordingly, as shown in FIGS. 6 and 7 , the gas inlet chamber 120 has an internal space to communicate with the upper portion of the discharge space 110 , and the upper portion thereof is connected to the exhaust line 20 . A connector 122 is formed. In this case, the connecting pipe 122 preferably has a shape having the same inner diameter as the inner diameter of the exhaust line 20 .

Of course, in the present embodiment, the gas inlet chamber 120 and the discharge space 110 may be integrally formed as shown in FIGS. 3 to 5 or may be formed separately and have a structure coupled to each other.

Next, as shown in FIGS. 3 and 4 , the gas discharge chamber 130 is installed in the lower portion of the discharge space 110 by connecting the exhaust line 20 and the discharge space 110 , It is a component for discharging the gas that has passed through the discharge space 110 to the exhaust line 20 . Accordingly, as shown in FIGS. 6 and 7 , the gas discharge chamber 130 also has a structure having a constant internal space to communicate with the lower portion of the discharge space 110 , and the lower portion thereof is connected to the exhaust line 20 . A connection pipe 132 is formed.

In this case, it is preferable that the connecting pipe 132 also has an inner diameter equal to the inner diameter of the exhaust fine 20 .

Of course, in the present embodiment, the gas discharge chamber 130 and the discharge space 110 may be integrally formed, or as shown in FIGS. 3 to 5 , may be formed separately and have a structure coupled to each other.

Next, as shown in FIGS. 3 and 4 , the ferrite core part 140 is a component installed to surround the outside of the discharge space part 110 . In the present embodiment, since the discharge space unit 110 has a structure in which the discharge spaces 111 and 112 are divided into two as described above, the ferrite core unit 140 also has two discharge spaces 111 and 112 . It has a structure that encloses all

Therefore, in this embodiment, the ferrite core part 140 includes two pairs of ferrite cores 141 and 142 installed side by side, respectively, and the two pairs of ferrite cores 141 and 142 are formed in the open space 143 . are the closest to each other. Therefore, as shown in FIG. 4 , the electric field induction part 150 is installed to surround the two pairs of ferrite cores 141 and 142 at once in the open space 143 .

As shown in FIGS. 3 and 4 , the electric field induction unit 150 is wound and installed in a structure surrounding the ferrite core unit 140 , and induces an electric field by AC power supplied from the power supply unit 160 . is a component At this time, the electric field induction unit 150 has the number of turns of 1 to 4, and preferably has an inductance of 10 to 200 μH. And in this embodiment, the start end of the electric field induction unit 150 is connected to the matching coil unit 170, and the end of the electric field induction unit 150 is grounded.

Next, the power supply unit 160 is a component that applies AC power to the electric field induction unit 150 as shown in FIGS. 12 to 15 . In this embodiment, the power supply unit 160 applies AC power to the electric field induction unit 150 via the matching coil unit 170, and specifically, it is preferable to supply power having a frequency of 100 to 500 kHz. do.

Next, the matching coil unit 170 is installed as one or more coils wound in such a way as to surround the gas inlet chamber 120 or the gas exhaust chamber 130 as shown in FIGS. 3 and 4 , and the power supply unit At 160 , it is a component that matches the AC power supplied to the electric field induction unit 150 . That is, the matching coil unit 170 is installed with a plurality of coils wound in a manner that surrounds either or both of the gas inlet chamber 120 and the gas discharge chamber 130 , and the connection method of each coil is changed. Accordingly, the AC power supplied to the electric field induction unit 50 is matched.

To this end, in the present embodiment, the matching coil unit 170 may include a first matching coil 171 and a second matching coil 174 as shown in FIGS. 3 and 4 . First, the first matching coil 171 is installed to surround the gas inlet chamber 120 , and is a component for primary matching by receiving AC power from the power supply unit 160 .

And as shown in FIGS. 3 and 4 , the first matching coil 171 includes a plurality of first coils 172 and a first coil connection part 173 surrounding the outside of the gas inlet chamber 120 . do. Here, as shown in FIGS. 3 and 4 , the first coil 172 is composed of a plurality of coils wrapped around the outside of the gas inlet chamber 120 several times, and the first coil connection part 173 is connected to the plurality of It is installed on the connection part of the first coil 172 and is a component for connecting a plurality of first coils 172 by changing them in series or parallel.

And in this embodiment, the first coils 172 are preferably installed outside the gas inlet chamber 120 stably by a coil installation jig 177 as shown in FIGS. 3 and 4 , and the coils The installation jig 177 has a plurality of installation slots so that the plurality of first coils 172 are wound at a constant interval and wound around the gas inlet chamber 120 .

In addition, as shown in FIGS. 3 and 4 , the second matching coil 174 is also installed to surround the gas exhaust chamber 130 , and receives AC power from the first matching coil 171 for secondary matching. is a component that That is, the second matching coil 174 is installed in electrical connection with the first matching coil 171 , and the second matching of the AC power first matched by the first matching coil 171 is performed again. .

In this embodiment, the detailed structure of the second matching coil 174 is substantially the same as that of the first matching coil 171 , and thus a repeated description thereof will be omitted.

Meanwhile, in the present embodiment, it is preferable that the first coil 172 or the second coil 175 have a size of 5 to 10 square because it is easy to move the AC power and install the coil. Here, 'square' refers to ^{mm 2} as a unit representing the cross-sectional area of the wire.

In general, in an AC circuit, the total impedance consists of the complex square root of the resistivity component, the capacitor component, and the inductance component. In the case of the plasma apparatus 100 using the ferrite core unit 140 used in this embodiment, since there are almost no resistive components and capacitor components, it can be seen that the total impedance consists of an inductance value. This can be expressed as an expression as follows.

< Equation 1 >

In general, since the plasma power device has a fixed output impedance, the plasma chamber side must also be configured to approximate this output impedance to effectively maintain the plasma. Therefore, a circuit capable of performing impedance matching between the plasma device and the power source is required, and in the present embodiment, the matching coil unit 170 is responsible for such a matching function.

Examples of matching by the matching coil unit 170 are shown in FIGS. 12 to 15 . First, in the case of FIG. 12 , the first matching coil 171 and the second matching coil 174 are connected in series, and a plurality of coils in the first and second matching coils 171 and 174 are also connected in series. In this case, the total impedance L(total) is obtained by the following equation.

< Equation 2 >

L(total) = L1 + L2

13 , a plurality of coils in the first and second matching coils 171 and 174 are connected in series with each other, and the first matching coil 171 and the second matching coil 174 are connected in parallel with each other. In this case, the total impedance L(total) is obtained by the following equation.

<Equation 3>

L(total) = L1×L2/(L1 + L2)

Also, in the case of FIG. 14 , the AC power supply skips the first matching coil 171 and is connected to pass only the second matching coil 174 , and all coils in the second matching coil 174 are connected in series. In this case, the total impedance L(total) is equal to L1.

Finally, in the case of FIG. 15 , the first matching coil 171 and the second matching coil 174 are connected in series, but a plurality of coils in the first and second matching coils 171 and 174 are connected in parallel with each other. In this case, the total impedance (L(total)) is obtained by the following equation.

<Equation 4>

L(total) = La×Lb/(La + Lb) + Lc×Ld/(Lc + Ld)

In this way, in the matching coil unit 170 according to the present embodiment, it is possible to provide a very diverse impedance by changing the connection relationship between the respective matching coils 171 and 174 and the connection relationship between the coils in one matching coil. Therefore, the impedance most suitable for plasma generation under the process conditions can be matched by changing the connection relationship between each coil.

In addition, as shown in FIGS. 8 and 9 , the plasma processing apparatus 100 having multiple matching coils according to the present embodiment preferably further includes a discharge pin 180 . As shown in FIGS. 8 and 9 , the discharge pins 180 are installed so that their ends are exposed in the inner spaces 111 and 112 of the discharge space 110 , and are components for igniting initial plasma.

To this end, in the present embodiment, the discharging pin 180 has a cross-sectional area of 0.5 cm ² or less on the distal end surface 183 for easy discharge. In addition, it is preferable for the discharge pin 180 to be supplied with power having a voltage of 15,000 to 20,000 V and a current of 100 mA or less for effective discharge.

Specifically, the discharge pin 180 is installed through the discharge pin installation hole 181 formed in the discharge space 110 by the discharge pin installation jig 182 .

And in the plasma processing apparatus 100 having multiple matching coils according to the present embodiment, power is applied to the discharge pin 180 when the plasma is ignited, and after power is applied to the ferrite core unit 140 , Preferably, a control unit (not shown in the drawing) for cutting off the power applied to the discharge pin 180 is further provided.

100: plasma processing apparatus having multiple matching coils according to the present invention
110: discharge space 120: gas inlet chamber
130: gas discharge chamber 140: ferrite core part
150: electric field induction unit 160: power supply
170: matching coil unit 180: discharge pin

Claims (8)

a discharge space unit installed in the exhaust line of the vacuum chamber, generating plasma in the internal space to process the gas moving in the internal space;
a gas inlet chamber installed in an upper portion of the discharge space by connecting the exhaust line and the discharge space, and configured to introduce a gas discharged through the exhaust line into the discharge space;
a gas discharge chamber installed at a lower portion of the discharge space by connecting the exhaust line and the discharge space, the gas exhaust chamber discharging the gas passing through the discharge space to the exhaust line;
a ferrite core part installed to surround the outside of the discharge space part;
an electric field induction part wound and installed in a structure surrounding the ferrite core part;
a power supply unit for applying AC power to the electric field induction unit;
Plasma with multiple matching coils including; a matching coil part installed with one or more coils wound in a manner that surrounds the gas inlet chamber or the gas exhaust chamber, and matching the AC power supplied from the power supply part to the electric field induction part processing unit. According to claim 1, wherein the discharge space portion,
Plasma processing apparatus with multiple matching coils, characterized in that it is made of aluminum and has a structure in which gas flow is divided in two directions. According to claim 1, wherein the matching coil unit,
a first matching coil installed to surround the gas inlet chamber and configured to receive AC power from the power supply and perform primary matching;
and a second matching coil installed to surround the gas exhaust chamber and configured to receive AC power from the first matching coil to perform secondary matching. According to claim 3, The first matching coil,
a plurality of first coils surrounding the outside of the gas inlet chamber;
and a first coil connection unit for connecting the plurality of first coils in parallel or in series. According to claim 3, The second matching coil,
a plurality of second coils surrounding the outside of the gas discharge chamber;
and a second coil connection unit for connecting the plurality of second coils in parallel or in series. 6. The method according to any one of claims 4 or 5,
The plasma processing apparatus having multiple matching coils, characterized in that the first coil or the second coil has a size of 5 to 10 square. According to claim 1, wherein the power supply unit,
Plasma processing apparatus having multiple matching coils, characterized in that supplying power having a frequency of 100 to 500 kHz. According to claim 1,
Plasma processing apparatus with multiple matching coils, characterized in that the discharge pin is installed so that the end is exposed in the inner space of the discharge space, and further comprises a discharge pin for igniting the initial plasma.

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