KR101232198B1 - Plasma generating unit, apparatus and method for treating substrate using plasma - Google Patents

Abstract

Provide a plasma generation unit. Plasma generating unit according to an embodiment of the present invention comprises a reaction chamber in which a space in which the plasma is generated; A Faraday shield having a hollow cylindrical shape with an open top and bottom, formed with a plurality of openings on a side thereof, and provided to surround the reaction chamber; A heat dissipation wall molded on an outer surface of the reaction chamber so that the Faraday shield is not exposed to the outside; And a coiled plasma antenna wound a plurality of times on the heat dissipation wall.

Description

Plasma generating unit and substrate processing apparatus and method including same {PLASMA GENERATING UNIT, APPARATUS AND METHOD FOR TREATING SUBSTRATE USING PLASMA}

The present invention relates to an apparatus for processing a substrate, and more particularly, to an apparatus for processing a substrate using plasma.

Fabrication of semiconductor devices, flat panel displays, and solar cells includes an ashing process for removing photoresist. The ashing process uses plasma to remove the photoresist.

As an example of an apparatus for generating plasma, an inductively coupled plasma (ICP) processing apparatus is proposed. The ICP treatment apparatus applies an electric current to a plasma antenna wound multiple times in a reaction chamber to form an induction electric field inside the reaction chamber, and the plasma source gas is excited in a plasma state by the induction electric field.

When plasma is generated using the above-described ICP processing apparatus, sputtering occurs in the reaction chamber. Sputtering damages the interior of the reaction chamber and generates particles. Internal damage to the process chamber reduces plasma generation and lower ashing rates. In addition, the heat generated in the process of generating the plasma is not radiated to the outside to generate a temperature difference according to the region of the reaction chamber. This generation of temperature difference causes breakage of the reaction chamber.

The present invention provides a plasma generating unit capable of stably generating plasma.

The present invention also provides a plasma generating unit capable of minimizing sputtering.

In addition, the present invention provides a plasma generating unit that can ensure the stability to heat.

Plasma generating unit according to an embodiment of the present invention comprises a reaction chamber in which a space in which the plasma is generated; A Faraday shield having a hollow cylindrical shape with an open top and bottom, formed with a plurality of openings on a side thereof, and provided to surround the reaction chamber; A heat dissipation wall molded on an outer surface of the reaction chamber so that the Faraday shield is not exposed to the outside; And a coiled plasma antenna wound a plurality of times on the heat dissipation wall.

In addition, the heat dissipation wall may be provided of a ceramic material.

In addition, the plasma antenna may have a contact surface in contact with the heat dissipation wall, and the contact surface may be a flat plane.

In addition, a cooling passage through which a cooling fluid flows may be formed in the plasma antenna.

In addition, the plasma antenna may include a power coil to which power is applied; Located adjacent to the power coil, it may include a mutual inductance coil to adjust the plasma spatial distribution in the reactor through mutual induction with the power coil.

According to one or more exemplary embodiments, a substrate processing apparatus includes a reaction chamber configured to process a substrate using plasma and a space in which plasma is generated; A Faraday shield having a hollow cylindrical shape with an open top and bottom, formed with a plurality of openings on a side thereof, and provided to surround the reaction chamber; A heat dissipation wall molded on an outer surface of the reaction chamber so that the Faraday shield is not exposed to the outside; And a coiled plasma antenna wound a plurality of times on the heat dissipation wall.

In addition, the process chamber is connected to the reaction chamber, the plasma generated in the reaction chamber is supplied; Located in the process chamber, it may further include a substrate support member for supporting the substrate.

The apparatus may further include a substrate support member positioned inside the reaction chamber and supporting the substrate.

In addition, the heat dissipation wall may be provided of a ceramic material.

In addition, the plasma antenna may have a contact surface in contact with the heat dissipation wall, and the contact surface may be a flat plane.

In the substrate processing method according to an embodiment of the present invention, a plasma source gas is supplied into the reaction chamber, a high frequency current is applied to the plasma antenna to form an electric field inside the reaction chamber, and plasma is generated by the electric field. Providing the plasma source gas excited to the substrate, wherein an axial electric field of the reaction chamber of the electric field formed in the plasma antenna is electrically shorted by the Faraday shielder, and in the process of generating the plasma Heat transmitted to the outside is discharged to the outside through the heat dissipation wall.

In addition, while the high frequency current is applied, a cooling fluid is supplied to the cooling flow path formed inside the plasma antenna, and the heat of the cooling fluid is transferred to the heat dissipation wall to cool the heat dissipation wall.

In addition, the plasma source gas may include hydrogen and nitrogen mixed in a predetermined ratio.

In addition, a process pressure at which the plasma processes the substrate may be 500 mTorr to 2.5 Torr.

In the present invention, since the occurrence of sputtering by the electric field is minimized, the plasma can be stably generated.

In addition, the present invention effectively releases the heat generated during the plasma generation process, it can be ensured the stability to the heat of the reaction chamber.

1 is a cross-sectional view showing a substrate processing apparatus according to an embodiment of the present invention.
1 is a view showing a substrate processing apparatus according to an embodiment of the present invention.
2 is a cross-sectional view taken along line A-A 'in Fig.
3 is a perspective view illustrating the Faraday shield of FIG. 2.
4 is a graph comparing substrate processing results.
5 is a cross-sectional view showing a plasma antenna according to another embodiment of the present invention.
6 is a cross-sectional view illustrating a substrate processing apparatus according to another embodiment of the present invention.

Hereinafter, a plasma generating unit, a substrate processing apparatus, and a method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a view showing a substrate processing apparatus according to an embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line AA 'of FIG. 1 and 2, the substrate processing apparatus 10 includes a process processing unit 100 and a plasma generating unit 200. The process processor 100 processes the substrate W using plasma. The plasma generation unit 200 generates plasma used for the processing of the substrate W. As shown in FIG. The generated plasma is provided to the process processor 100 in a down stream manner.

The process processor 100 may include a process chamber 110, a substrate support member 120, a lead 130, and a baffle 140.

The process chamber 110 is open at an upper portion thereof and provides a process space 111 in which a substrate processing process is performed. Exhaust holes 112 are formed at the bottom of the process chamber 110. Exhaust pipes 113 are coupled to the exhaust holes 112. The reaction by-products generated during the substrate processing and the process gas introduced into the process space are discharged to the outside through the exhaust holes 112 and the exhaust pipe 113. A pressure regulator (not shown) may be connected to the exhaust pipes 113, and the pressure inside the process chamber 110 may be adjusted by the pressure regulator (not shown). The process chamber 110 may be maintained at 500 mTorr to 2.5 Torr while the substrate process is performed.

The substrate support member 120 supports the substrate W in the process chamber 110. The substrate support member 120 includes a susceptor 121 and a support shaft 122. The susceptor 121 is provided in a disc shape, and the substrate W is placed on an upper surface thereof. The susceptor 121 may be one of an electrostatic chuck and a vacuum chuck. Inside the susceptor 121, a heating coil (not shown) and a cooling coil (not shown) may be provided. The heating coil heats the substrate W to a preset temperature. In an ashing process, the substrate temperature may be heated to about 200 ° C. The susceptor 121 may be provided of aluminum or a ceramic material so that the temperature is effectively transmitted to the substrate (W). The cooling coil forcibly cools the heated substrate (W). The board | substrate W in which process process is completed is cooled to the temperature required for normal temperature state or a next process process. The support shaft 122 has a cylindrical shape and supports the susceptor 121 at the bottom of the susceptor 121.

The lid 130 may have an inverted funnel shape with an open lower portion, and a diffusion space 131 for dispersing plasma is provided inside the lid 130. The lid 130 is coupled to an open upper portion of the process chamber 110 to seal the inside of the process chamber 110. An inlet 132 is formed at the center of the upper end of the lead 130. The inlet 132 is connected with the plasma generating unit 200. The plasma generated in the plasma generating unit 200 is introduced into the diffusion space 131 through the inlet 132 and diffused in the diffusion space 131.

The baffle 140 is disposed above the susceptor 121 to face the susceptor 121. The baffle 140 partitions the process space 111 and the diffusion space 131. Injection holes 141 are formed in the baffle 140, and components of the plasma are selectively transmitted from the diffusion space 131 to the process space 111 through the injection holes 141. The baffle 140 may be grounded to mainly transmit radical components of the plasma into the process space 111.

The plasma generating unit 200 is coupled to the lead 130 and generates plasma to provide the diffusion space 131. The plasma generation unit 200 includes a reaction chamber 210, a source gas supply member 220, a Faraday shield 230, a heat dissipation wall 240, and a plasma antenna 250.

The reaction chamber 210 has a cylindrical tube shape, and a space 211 in which plasma is generated is formed. The reaction chamber 210 has an open bottom, and the open bottom is connected to the inlet 132 of the lid 130. The inner diameter of the reaction chamber 210 may be maintained at 110mm to 130mm. According to an embodiment, the inner diameter of the reaction chamber 210 may be maintained at 120 mm. The inner diameter of the reaction chamber 210 requires a corresponding inner diameter as the substrate is largely cured. The reaction chamber 210 having an internal diameter of 60 mm is suitable for processing a 300 mm substrate, but is not suitable for processing a 450 mm substrate. In the present invention, by expanding the inner diameter of the reaction chamber 210, not only a 300 mm substrate but also a 450 mm substrate can be processed. The reaction chamber 210 may be provided of any one material of quartz, sapphire, and ceramic. The source gas supply member 220 is coupled to the top of the reaction chamber 210 and supplies a plasma source gas into the reaction chamber 210. For example, the plasma source gas may include at least one of nitrogen, oxygen, hydrogen, helium, neon. The plasma source gas may include nitrogen and hydrogen mixed in a proportion. The ratio of hydrogen and nitrogen can be any one of 9: 1, 8: 2, 7: 3, 6: 4, 5: 5, 4: 6, 3: 7, 2: 8, and 1: 9.

The Faraday shield 230 is provided to surround the reaction chamber 210. As shown in FIG. 3, the Faraday shield 230 has a hollow cylinder shape with open top and bottom. A plurality of openings 231 are formed at the side of the Faraday shield 230. The opening 231 may have a slit shape extending in the vertical direction. The top and bottom of the opening 231 can be rounded. A plurality of openings 231 having the above-described shape are spaced apart along the side surface of the Faraday shield 230. Faraday shield 230 may be provided with a conductive material. Faraday shield 230 may be provided with a copper material. Faraday shield 230 is grounded. The plasma antenna 250 to which the high frequency power is applied may generate a capacitively coupled plasma together with an inductively coupled plasma. The Faraday shield 230 electrically shorts the axial electric field generated by the plasma antenna 250 to suppress the generation of capacitively coupled plasma. As a result, an inductively coupled plasma may be generated in the reaction chamber 210. In addition, the Faraday shield 230 electrically shorts the axial electric field generated by the plasma antenna 250 to suppress sputtering. As a result, internal damage and particle generation of the reaction chamber 210 due to sputtering can be suppressed.

The heat dissipation wall 240 is molded on the outer surface of the reaction chamber 210 so that the Faraday shield 230 is not exposed to the outside. The heat dissipation wall 240 is formed to a predetermined thickness and is attached to the outer side of the reaction chamber 210 along the circumference of the reaction chamber 210. The heat dissipation wall 240 is provided in the openings 231 of the Faraday shield 230. The heat dissipation wall 240 is provided of a material having high thermal conductivity. The heat dissipation wall 240 may be provided of a ceramic material. Ceramic-based materials have excellent heat dissipation effect because they have higher thermal conductivity and thermal expansion coefficient than quartz or sapphire. The heat dissipation wall 240 cools the reaction chamber 240 by dissipating heat generated inside the reaction chamber 210 to the outside during the plasma generation process.

The plasma antenna 250 is wound around the heat dissipation wall 240 a plurality of times. The plasma antenna 250 is an inductively coupled plasma (ICP) antenna and has a coil shape. The plasma antenna 250 has a contact surface 251 in contact with the heat dissipation wall 240. Since the contact surface 251 is provided in a flat plane, an area in which the plasma antenna 250 is in contact with the heat dissipation wall 240 may be widened. The contact surface 251 improves heat transfer efficiency between the plasma antenna 250 and the heat dissipation wall 240. The plasma antenna 250 may have a rectangular cross section, and one surface 251 may be in contact with the heat dissipation wall 240. The cooling passage 252 is formed inside the plasma antenna 240. The cooling fluid supplied from the cooling fluid supply unit (not shown) circulates through the cooling passage 252. The cooling fluid may be provided in a liquid state or a gaseous state. The heat of the cooling fluid circulating in the cooling passage 252 is transferred to the heat dissipation wall 240 to cool the reaction chamber 210.

The plasma antenna 250 includes a power coil 254 and mutual induct coils 255 and 256. The power coil 254 may be wound around the center of the reaction chamber 210 a plurality of times along the length direction of the reaction chamber 210. A high frequency power supply 261 is connected to one end of the power coil 254, and the other end of the power coil 254 is grounded. When a high frequency current is applied to the power coil 254 from the high frequency power supply 261, a magnetic field is formed in the internal space 211 of the reaction chamber 210, and an induction electric field is formed inside the reaction chamber 210 by the magnetic field. do. The plasma source gas supplied from the source gas supply member 220 to the process chamber 210 is converted into a plasma state by obtaining energy required for ionization from an induction electric field. In this case, the generated plasma may have a bell-shaped distribution that is vertically symmetrical with respect to the center portion along the longitudinal direction of the reaction chamber 210.

The mutual inductance coils 255 and 256 are located adjacent to the power coil 254 and regulate the plasma spatial distribution in the reaction chamber 210 through mutual induction with the power coil 254. The mutual inductance coils 255 and 256 may include an upper coil 255 and a lower coil 256. The upper coil 255 is wound a plurality of times in the reaction chamber 210 at the top of the power coil 254. The upper coil 255 is grounded at one end. The other end of the upper coil 255 may be connected by a grounded end and the switch 262 to be electrically connected or short-circuited. When both ends of the upper coil 255 are electrically connected by the switch 262, no mutual induction action occurs in the upper coil 255. On the other hand, when one end and the other end of the upper coil 255 is electrically shorted, the mutual induction action occurs in the complementary coil 255. The lower coil 256 is wound several times in the reaction chamber 210 under the power coil 254. One end of the lower coil 256 is grounded. The other end of the lower coil 256 may be connected by a grounded end and a switch 263 to be electrically connected or short-circuited. When both ends of the lower coil 256 are electrically connected by the switch 263, the mutual induction action does not occur in the lower coil 256. On the other hand, if one end and the other end of the lower coil 256 is electrically shorted, mutual induction action occurs in the lower coil 256. The mutual induction action refers to a phenomenon in which an electric field is formed in the lower coil 256 or the upper coil 255 by a magnetic field formed by the power coil 254, and a magnetic field is formed by the formed electric field. By mutual induction, the magnetic field formed by the power coil 254, the magnetic field formed by the upper coil 255, and the magnetic field formed by the lower coil 256 are complemented, and react by mutual complementary magnetic fields. The spatial distribution of the plasma is controlled in the chamber 210. The spatial distribution control of the plasma increases the amount of plasma in the region where the magnetic field is formed.

A process of processing a substrate using the substrate processing apparatus according to the present invention described above will be described. 1 and 2, the plasma source gas is supplied into the reaction chamber 210 from the source gas supply member 220. When a current is supplied from the high frequency power supply 261 to the plasma antenna 250, a magnetic field is formed in the reaction chamber 210. The formed magnetic field forms an induction electric field inside the reaction chamber 210. The plasma source gas is converted into a plasma state by the induced magnetic field. Among the magnetic field components formed by the plasma antenna 250, the axial electric field of the reaction chamber 210 is electrically shorted by the Faraday shielder 230. As a result, the capacitively coupled plasma generation can be suppressed in the reaction chamber 210, and the inductively coupled plasma can be generated. Heat generated in the process of generating plasma is transferred to the reaction chamber 210. Heat transferred to the reaction chamber 210 is discharged to the outside through the heat dissipation wall 240. While the high frequency current is applied to the plasma antenna 250, the cooling fluid circulates through the cooling passage 252 formed inside the plasma antenna 250. Heat of the circulating cooling fluid is transferred to the heat dissipation wall 240 to cool the heat dissipation wall 240. By the heat dissipation by the heat dissipation wall 240 and cooling of the heat dissipation wall 240 by the cooling fluid, the reaction chamber 210 may be protected from heat generated in the process of forming plasma. The formed plasma is supplied to the process chamber 110 and provided for substrate processing.

4 is a graph comparing substrate processing results.

Referring to FIG. 4, the substrate treatment was performed at the same process pressure, plasma source gas, and process time. Substrate treatment results shown in the graph are performed under a process pressure of 650 mTorr, a plasma source gas containing 3500 sccm H2 and 4200 sccm N2, and a process time of 30 seconds. The X axis of the graph represents the number of tests, and the test was performed four times in total. In each test, the same number of substrates were processed. The Y axis of the graph represents the average ashing rate of the substrates. Graph I (A) shows the ashing rate of the substrate subjected to the process treatment using the substrate processing apparatus of the present invention, and graph II (B) shows the ashing rate of the substrate subjected to the process treatment using the apparatus to be compared. . The device to be compared is a device having an inner diameter of 60 mm in the process chamber, a Faraday shielder and a heat dissipation wall not provided, and a contact surface of the plasma antenna not provided in a plane. Referring to the graph of FIG. 4, graph I (A) shows a constant ashing rate of each test at about 2500 mW / min. On the other hand, graph II (B) shows an ashing rate of 3750 kV / min in test 1, an ashing rate of about 2500 kV / min in tests 2 and 3 and an ashing rate of 1250 kV / min in test 4. The results shown in graph II (B) show that the ashing rate is not uniform according to the substrate to be processed, and the ashing rate decreases as the number of substrates to be processed increases. Through the graphs I (A) and II (B), when the substrate is processed using the substrate processing apparatus of the present invention, the ashing rate appears uniformly and there is a large difference in the ashing rate even if the number of substrates to be processed is increased. It can be seen that it does not occur.

5 is a cross-sectional view showing a plasma antenna according to another embodiment of the present invention. Referring to FIG. 5, unlike the plasma antenna of FIG. 2, the plasma antenna 250 has a semicircular cross section. The flat inner surface 251 of the plasma antenna 250 is provided as a contact surface in contact with the heat dissipation wall 240. As such, the shape of the plasma antenna 250 may be variously modified in a range in which the contact surface 251 is provided in a flat plane.

6 is a cross-sectional view illustrating a substrate processing apparatus according to another embodiment of the present invention. Referring to FIG. 6, the internal space 311 of the reaction chamber 310 is provided as a space in which a substrate processing process is performed, as well as a plasma generating space in which plasma is generated. The susceptor 315 supports the substrate W in the reaction chamber 310. The source gas supply member 320 is connected to the upper wall of the reaction chamber 310, and the plasma source gas is supplied into the reaction chamber 310 through the source gas supply member 320. An exhaust hole 312 is formed in the lower wall of the reaction chamber 310, and reaction by-products and process gas are discharged to the outside through the exhaust hole 312 and the exhaust pipe 313. The Faraday shield 330 is provided to surround the reaction chamber 310. The Faraday shield 330 may have the same shape as the Faraday shield 230 shown in FIG. 3. The heat dissipation wall 340 is molded on the outer surface of the reaction chamber 210 so that the Faraday shield 330 is not exposed to the outside. The heat dissipation wall 240 may be provided as a ceramic material, and discharges heat generated during plasma generation to the outside of the reaction chamber 310. The plasma antenna 350 is provided to be wound on the heat dissipation wall 340 a plurality of times. One end of the plasma antenna 350 is connected to the high frequency power supply 355 and the other end is grounded. A magnetic field is formed in the plasma antenna 350 by the high frequency current applied from the high frequency power source 355, and the magnetic field forms an induction electric field in the reaction chamber 310. The induction electric field is provided as energy for converting the plasma source gas into the plasma state. The contact surface 351 of the plasma antenna 350 in contact with the heat dissipation wall 340 is provided in a flat plane. The contact surface 351 increases the contact area between the heat dissipation wall 340 and the plasma antenna 350. Due to the increased contact area, the heat of the cooling fluid circulating in the cooling channel 352 formed inside the plasma antenna 350 is effectively transferred to the heat dissipation wall 340, thereby increasing the cooling efficiency of the reaction chamber 310. .

In the above-described embodiment, the ashing treatment using plasma has been described as an example. However, the present invention is not limited thereto and may be applied to various process treatments using plasma, for example, an etching process and a deposition process.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

100: process processing unit 200: plasma generating unit
210: reaction chamber 220: source gas supply member
230: Faraday shield 240: heat dissipation wall
250: plasma antenna

Claims (15)

A reaction chamber in which a space in which plasma is generated is formed;
A Faraday shield having a hollow cylindrical shape with an open top and bottom, formed with a plurality of openings on a side thereof, and provided to surround the reaction chamber;
A heat dissipation wall molded on an outer surface of the reaction chamber so that the Faraday shield is not exposed to the outside; And
And a coil-shaped plasma antenna wound around the heat dissipation wall a plurality of times. The method of claim 1,
The heat generating wall is a plasma generating unit provided with a ceramic material. The method of claim 1,
The plasma antenna has a contact surface in contact with the heat dissipation wall,
And said contact surface is a flat plane. The method of claim 3, wherein
And a cooling passage through which a cooling fluid flows inside the plasma antenna. The method of claim 3, wherein
The plasma antenna
A power coil to which power is applied;
And a mutual inductance coil positioned adjacent to the power coil, the mutual inductance coil adjusting the plasma spatial distribution in the reaction chamber through mutual induction with the power coil. In the apparatus for processing a substrate using a plasma,
A reaction chamber in which a space in which plasma is generated is formed;
A Faraday shield having a hollow cylindrical shape with an open top and bottom, formed with a plurality of openings on a side thereof, and provided to surround the reaction chamber;
A heat dissipation wall molded on an outer surface of the reaction chamber so that the Faraday shield is not exposed to the outside; And
And a coiled plasma antenna wound around the heat dissipation wall a plurality of times. The method according to claim 6,
A process chamber connected to the reaction chamber and supplied with plasma generated in the reaction chamber;
And a substrate support member positioned inside the process chamber and supporting the substrate. The method according to claim 6,
And a substrate support member positioned inside the reaction chamber and supporting the substrate. The method according to claim 6,
The inner diameter of the reaction chamber is 110mm to 130mm substrate processing apparatus. The method according to any one of claims 6 to 9,
The heat dissipation wall is a substrate processing apparatus provided with a ceramic material. The method according to any one of claims 6 to 9,
The plasma antenna has a contact surface in contact with the heat dissipation wall,
And the contact surface is a flat plane. A method of treating a substrate using the apparatus of any one of claims 6 to 9,
Supplying a plasma source gas into the reaction chamber,
Applying a high frequency current to the plasma antenna to form an electric field inside the reaction chamber,
Providing the plasma source gas excited to the plasma state by the electric field to the substrate,
The axial electric field of the reaction chamber of the electric field formed in the plasma antenna is electrically shorted by the Faraday shielder,
The heat transfer to the reaction chamber in the process of generating the plasma is discharged to the outside through the heat dissipation wall. 13. The method of claim 12,
While the high frequency current is applied, a cooling fluid is supplied to the cooling flow path formed inside the plasma antenna,
And heat of the cooling fluid is transferred to the heat dissipation wall to cool the heat dissipation wall. 13. The method of claim 12,
The plasma source gas includes a hydrogen and nitrogen mixed in a predetermined ratio. 13. The method of claim 12,
And a process pressure at which the plasma processes the substrate is 500 mTorr to 2.5 Torr.

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