JP5715210B2 - Substrate processing method - Google Patents

Description

The present invention relates to a substrate processing how, and more particularly how to process the substrate using plasma.

  In recent years, semiconductors have become increasingly highly integrated and form fine patterns, so that trace amounts of contaminants can affect the characteristics of the semiconductor. Above all, an ultra-clean surface is necessary for the development of such ultrafine devices. In order to realize this, it is necessary to remove various contaminants present on the substrate and to control the surface roughness.

  Among these contaminants, a natural oxide film generated on the substrate surface is formed by oxygen present in the atmosphere. FIG. 1 is a view showing an example of a substrate on which a natural oxide film is formed, and the natural oxide film C2 can be formed on the photoresist film C1 applied to the pattern b of silicon a. Even if the natural oxide film is completely removed, 5 to 20 cm grows after 24 hours.

  When an oxide film is formed on the gate, device characteristics are deteriorated and resistance is increased. When an oxide film is formed on the contact surface, the contact resistance is increased to hinder subsequent deposition of the conductor. As semiconductors are highly integrated, such oxide film removal is gradually recognized as an important factor. In particular, there is a method for effectively removing an oxide film by reducing damage of a substrate on which a pattern is formed. Required.

Korean Patent Publication No. 10-2011-0061334

The present invention provides a substrate processing how readily remove the oxide film formed on a substrate.

According to an embodiment of the present invention, there is provided a substrate processing method, comprising: supplying ozone to a discharge space; supplying a source gas to the discharge space; supplying a source gas to the discharge space; A second processing stage in which a gas is discharged into a plasma state, and the discharged source gas flows into the processing space to process the substrate, while the ozone passes through the discharge space. No power is applied to the induction coil surrounding the .

The first processing step may further include a step of supplying water vapor to the discharge space, and the water vapor flows into the processing space to process the substrate.

  According to the embodiment of the present invention, the natural oxide film or the chemical oxide film formed on the substrate is easily removed.

It is drawing which shows an example of the board | substrate with which the natural oxide film was formed. It is a top view which shows simply the substrate processing equipment by the embodiment of the present invention. 1 is a schematic view illustrating a substrate processing apparatus according to an embodiment of the present invention. 5 is a view illustrating a substrate processing apparatus according to another embodiment of the present invention. 5 is a view showing a substrate processing apparatus according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to the following embodiments. This embodiment is provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes of elements in the drawings are exaggerated to emphasize a clearer description.

  FIG. 2 is a plan view schematically showing a substrate processing facility according to an embodiment of the present invention.

  Referring to FIG. 2, the substrate processing facility 1 includes an equipment front end module (EFEM) 10 and a process processing chamber 20. The equipment front end module (EFEM) 10 and the process chamber 20 are arranged in one direction. Hereinafter, the direction in which the equipment front end module (EFEM) 10 and the process chamber 20 are arranged is defined as the first direction (X), and when viewed from above, the direction is perpendicular to the first direction (X). Is defined as being in the second direction (Y).

  The equipment front end module 10 is mounted in front of the process chamber 20 and transfers the substrate W between the carrier 16 containing the substrate and the process chamber 20. The equipment front end module 10 includes a load port 12 and a frame 14.

  The load port 12 is disposed in front of the frame 14, and a plurality of the load ports 12 are provided. The load ports 12 are arranged in a row according to the second direction 2 so as to be separated from each other. Carriers 16 (eg, cassettes, FOUPs, etc.) are each seated on load port 12. The carrier 16 stores a substrate W provided for the process and a substrate W that has been processed.

  The frame 14 is disposed between the load port 12 and the load lock chamber 22. A transfer robot 18 that transfers the substrate W between the load port 12 and the load lock chamber 22 is disposed inside the frame 14. The transfer robot 18 is movable in accordance with a transfer rail 19 provided in the second direction (Y).

  The process chamber 20 includes a load lock chamber 22, a transfer chamber 24, and a plurality of substrate processing apparatuses 30.

  The load lock chamber 22 is disposed between the transfer chamber 24 and the frame 14, and the substrate W provided for the process is transferred to the substrate processing apparatus 30 or the substrate W that has been processed is transferred to the carrier 16. Provide space to wait before being done. One or more load lock chambers 22 may be provided. According to the embodiment, two load lock chambers 22 are provided. One load lock chamber 22 contains a substrate W to be provided to the substrate processing apparatus 30 for process processing, and the other one of the load lock chambers 22 contains a substrate W that has been processed by the substrate processing apparatus 30. Can be stored.

  The transfer chamber 24 is disposed behind the load lock chamber 22 in the first direction (X), and has a polygonal body 25 when viewed from above. A load lock chamber 22 and a plurality of substrate processing apparatuses 30 are arranged outside the main body 25 according to the periphery of the main body 25. According to an embodiment, the transfer chamber 24 has a hexagonal body when viewed from above. A load lock chamber 22 is disposed on each of two side walls adjacent to the equipment front end module 10, and a substrate processing apparatus 30 is disposed on the remaining side walls. A passage (not shown) through which the substrate W enters and exits is formed on each side wall of the main body 25. The passage provides a space for the substrate W to enter and exit between the transfer chamber 24 and the load lock chamber 22 or between the transfer chamber 24 and the substrate processing apparatus 30. Each passage is provided with a door (not shown) for opening and closing the passage. The transfer chamber 24 can be provided in various shapes depending on the required process module.

  A transfer robot 26 is disposed inside the transfer chamber 24. The transfer robot 26 transfers the unprocessed substrate W waiting in the load lock chamber 22 to the substrate processing apparatus 30, or transfers the substrate W that has been processed by the substrate processing apparatus 30 to the load lock chamber 22. The transfer robot 26 can sequentially provide the substrates W to the substrate processing apparatus 30.

  The substrate processing apparatus 30 performs a process by supplying a plasma state gas to the substrate. Plasma gas can be used in various ways in semiconductor manufacturing processes. Hereinafter, the substrate processing apparatus 30 has been described as performing an ashing process. However, the present invention is not limited to this, and may be applied to various processes using a plasma gas, such as an etching process and a deposition process. obtain.

  FIG. 3 is a schematic view illustrating a substrate processing apparatus according to an embodiment of the present invention.

  Referring to FIG. 3, the substrate processing apparatus 30 includes a process processing unit 100, a plasma generation unit 200, and a gas supply unit 300. The process processing unit 100 provides a space where the processing of the substrate W is performed, and the plasma generation unit 200 generates plasma used in the processing process of the substrate W, and the plasma is transferred to the substrate W in a downstream (Down Stream) system. Supply. The gas supply unit 300 supplies a gas for generating plasma to the plasma generation unit 200. Hereinafter, each configuration will be described in detail.

  The process processing unit 100 includes a process chamber 110, a susceptor 140, and a shower head 150.

  The process chamber 110 provides a processing space TS where the processing of the substrate W is performed. The process chamber 110 has a body 120 and a sealing cover 130. The upper surface of the body 120 is opened, and a space is formed inside. An opening (not shown) through which the substrate W enters and exits is formed on the side wall of the body 120, and the opening is opened and closed by an opening / closing member such as a slit door (not shown). The opening / closing member closes the opening while the processing of the substrate W is performed in the process chamber 110, and opens when the substrate W is loaded into the process chamber 110 and unloaded from the process chamber 110. Open. An exhaust hole 121 is formed in the lower wall of the body 120. The exhaust hole 121 is connected to the exhaust line 170. The internal pressure of the process chamber 110 is adjusted through the exhaust line 170, and the reaction product generated in the process is discharged to the outside of the process chamber 110.

  The sealing cover 130 is coupled to the upper wall of the body 120 and covers the open upper surface of the body 120 to seal the inside of the body 120. The upper end of the hermetic cover 130 is connected to the plasma supply unit 200. A guide space DS is formed in the hermetic cover 130. The plasma flowing in by the plasma supply unit 200 is diffused in the induction space DS and moves to the shower head 150.

  The susceptor 140 is positioned in the processing space TS and supports the substrate W. The susceptor 140 may be provided with an electrostatic static chuck that attracts the substrate W by electrostatic force. A lift hole (not shown) may be formed in the susceptor 140. Each lift hole is provided with a lift pin (not shown). The lift pins move up and down along the lift holes when the substrate W is loaded / unloaded onto the susceptor 140. A heater 141 may be provided inside the susceptor 140. The heater 141 heats the substrate W to maintain the process temperature.

  The shower head 150 is coupled to the upper wall of the body 120 between the body 120 and the sealing cover 130. The shower head 150 is provided in a disc shape and is disposed in parallel with the upper surface of the susceptor 140. The shower head 150 is provided with a flat surface facing the susceptor 140. The shower head 150 may be provided in a larger area than the substrate W. A hole 151 is formed in the shower head 150. The plasma gas diffused in the induction space DS is supplied to the substrate W through the hole 151.

  The plasma generator 200 is located at the upper part of the process chamber 110 and discharges the gas to generate plasma gas. The plasma generator 200 includes a reactor 211, a gas injection port 212, an induction coil 215, and a power source 217.

  The reactor 211 has a cylindrical shape, and an upper surface and a lower surface are opened to form a space inside. The interior of the reactor 211 is provided to a discharge space ES where gas is discharged.

  A gas injection port 212 is coupled to the upper end of the reactor 211. The gas injection port 212 is connected to the gas supply unit 300 and supplied with gas. An induction space IS is formed on the bottom surface of the gas injection port 212. The induction space IS has a reverse funnel shape and communicates with the discharge space ES. The gas flowing into the induction space IS is diffused and provided to the discharge space ES.

  The induction coil 215 is wound around the reactor 211 a plurality of times along the periphery of the reactor 211. One end of the induction coil 215 is connected to the power source 217, and the other end is grounded. The power source 217 applies high frequency power or microwave power to the induction coil 215.

  The gas supply unit 300 supplies gas to the discharge space ES. The gas supply unit 300 includes a first gas supply line 310, a second gas supply line 320, a source gas storage unit 330, a steam generation unit 340, and a pure water supply line 350.

The first gas supply line 310 has one end connected to the gas injection port 212 and the other end connected to the source gas storage unit 330. The first gas supply line 310 supplies the source gas stored in the source gas storage unit 330 to the discharge space ES. The source gas may include at least one of NH ₃ , O ₂ , N ₂ , H ₃ , and NF ₃ CH ₄ . The source gas storage unit 330 can include a plurality of storage units 331, 332, 333,. In this case, the end of the first gas supply line 310 may be branched into a plurality of parts and connected to the storage units 331, 332, 333,. In contrast, the source gas may be provided as a mixed gas in which the above-described gases are mixed and stored in one storage unit.

  The second gas supply line 320 is branched from the first gas supply line 310, and one end is connected to the first gas supply line 310. A steam generator 340 is installed on the second gas supply line 320. The steam generating unit 340 is connected to a pure water supply line 350, and pure water (DI-water) is supplied from the pure water supply line 350. The steam generation unit 340 heats pure water to change the state to a steam state, and supplies the generated water vapor to the second gas supply line 320.

  A first valve 361 is installed in the first gas supply line 310 in a section between the point where the second gas supply line 320 branches from the first gas supply line 310 and the source gas storage unit 330. The first valve 361 opens and closes the first gas supply line 310 to adjust the supply of source gas.

  A second valve 362 is installed in the second gas supply line 320. The second valve 362 opens and closes the second gas supply line 320 to adjust the supply of water vapor.

  Hereinafter, a method for processing a substrate using the above-described substrate processing apparatus will be described.

  As shown in FIG. 1, the substrate processing method removes the photoresist C1 on which the oxide film C2 is formed. The substrate processing method includes a first processing stage and a second processing stage. The susceptor 140 may be maintained at a temperature of about 350 ° C. or lower by heating the heater 141 while the first processing stage and the second processing stage are performed.

  In the first processing stage, water vapor is supplied to the discharge space ES, and the water vapor flows into the processing space TS to process the substrate W. Pure water is supplied to the steam generator 340 through the pure water supply line 350. The steam generator 340 heats pure water to generate a steam state, and the steam is supplied to the discharge space ES through the second gas supply line 320 and the first gas supply line 310 in order.

  Electric power is applied from the power source 217 to the induction coil 215 while the water vapor passes through the discharge space ES. The applied electric power forms an induction electric field in the discharge space ES, and the water vapor obtains energy necessary for ionization from the induction electric field and is discharged into a plasma state. The discharged water vapor has hydroxide ions and hydrogen ion active species, and the oxygen content is minimized. The discharged water vapor is provided to the processing space TS to primarily process the photoresist film C1 and the oxide film C2.

  In contrast, it is possible that no power is applied to the induction coil 215 while water vapor passes through the discharge space ES. The water vapor flows through the processing space TS to primarily process the photoresist film C1 and the oxide film C2.

  The second treatment stage supplies the source gas to the discharge space ES after the primary stage. Electric power is applied from the power source 217 to the induction coil 215 while the source gas passes through the discharge space ES. The source gas is discharged into a plasma state by the applied power. The discharged source gas flows into the processing space TS and secondarily processes the photoresist film C1 and the oxide film C2.

  The photoresist film C1 on which the oxide film C2 is formed can be removed from the substrate W through the first processing stage and the second processing stage described above.

  FIG. 4 is a view showing a substrate processing apparatus according to another embodiment of the present invention.

  Referring to FIG. 4, the substrate processing apparatus 30 ′ is provided in the same manner as the above-described substrate processing apparatus 30 except for the gas supply unit 400. Unlike the embodiment of FIG. 3, an ozone generator 440 is connected to the second gas supply line 420. The ozone generator 440 generates ozone and supplies it to the second gas supply line 420.

  The substrate processing method according to the embodiment of the present invention supplies ozone generated by the ozone generator 440 to the discharge space ES through the second gas supply line 420 and the first gas supply line 410.

While ozone passes through the discharge space ES, power is applied from the power source 217 to the induction coil 215. Ozone is discharged into a plasma state by applying power. The discharged ozone is provided to the processing space TS to primarily process the photoresist film C1 and the oxide film C2. Ozone is decomposed into O and O ₂ in the process of being discharged into a plasma state, and these are combined again to generate O ₃ . O ₃ generates O and O ₃ through a reaction that is decomposed again into O and O ₂ . Since these remove organic contaminants by changing them into volatile compounds, they are effective in removing the photoresist C1 and the oxide film C2.

  In contrast, it is possible that no power is applied to the induction coil 215 while ozone passes through the discharge space ES. Ozone flows through the processing space TS and primarily processes the photoresist film C1 and the oxide film C2.

  When the treatment with ozone is completed, the source gas is supplied to the discharge space ES. While the source gas passes through the discharge space ES, power is applied from the power source 217 to the induction coil 215. The source gas is discharged into a plasma state by the applied power. The discharged source gas flows into the processing space TS and secondarily processes the photoresist film C1 and the oxide film C2.

  The photoresist film C1 on which the oxide film C2 is formed can be removed from the substrate W through the first processing stage and the second processing stage described above.

  FIG. 5 is a view showing a substrate processing apparatus according to another embodiment of the present invention.

  Referring to FIG. 5, unlike the above-described embodiment, a steam generator 540 and an ozone generator 560 are connected to the second gas supply line 520. The other end of the second gas supply line 520 is branched into two and connected to a steam generator 540 and an ozone generator 560, respectively.

  The steam generator 540 is connected to the pure water supply line 550 and heats the pure water supplied from the pure water supply line 550 to generate a vapor state. The water vapor is supplied to the discharge space ES through the second gas supply line 520 and the first gas supply line 510.

  The ozone generator 560 generates ozone, and the ozone is supplied to the discharge space ES through the second gas supply line 520 and the first gas supply line 510.

  Water vapor and ozone can be sequentially supplied to the discharge space ES. Unlike this, water vapor and ozone can be simultaneously supplied to the discharge space ES.

  Electric power is applied from the power source 217 to the induction coil 215 while water vapor and ozone pass through the discharge space ES. By applying electric power, water vapor and ozone are discharged into a plasma state. The discharged water vapor and ozone are provided to the processing space TS to primarily process the photoresist film C1 and the oxide film C2.

  In contrast, it is possible that no power is applied to the induction coil 215 while water vapor and ozone pass through the discharge space ES. Water vapor and ozone flow through the processing space TS to primarily process the photoresist film C1 and the oxide film C2.

  When the treatment with water vapor and ozone is completed, the source gas is supplied to the discharge space ES. While the source gas passes through the discharge space ES, power is applied from the power source 217 to the induction coil 215. The source gas is discharged into a plasma state by the applied power. The discharged source gas flows into the processing space TS and secondarily processes the photoresist film C1 and the oxide film C2.

  In the above-described embodiment, it has been described that the oxide film formed on the photoresist film is removed, but the oxide film that can be processed by the above-described method is not limited thereto. The substrate processing method can remove the oxide film formed in the pattern.

  The foregoing detailed description is merely illustrative of the invention. Also, the foregoing is intended to illustrate and describe the preferred embodiment of the present invention, and the present invention can be used in a variety of other combinations, modifications and environments. That is, changes or modifications can be made within the scope of the inventive concept disclosed in the present specification, the scope equivalent to the above-described disclosure, and / or the skill or knowledge of the industry. The above-described embodiments are for explaining the best state for embodying the technical idea of the present invention, and various modifications required in specific application fields and applications of the present invention are possible. Accordingly, the above detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other implementations.

30, 30 ', 30 "... substrate processing apparatus,
100 ... process processing part,
200 ... plasma generator,
300, 400, 500 ... gas supply unit,
310, 410, 510 ... first gas supply line,
320, 420, 520 ... second gas supply line,
330, 430, 530 ... source gas storage unit,
340, 540 ... steam generating part,
350, 550 ... pure water supply line,
440, 560 ... Ozone generator.

Claims (2)

Supplying ozone to the discharge space, and the ozone flows into the processing space to process the substrate;
Supplying a source gas into the discharge space, the source gas was discharged into a plasma state, it viewed including a second processing stage, the discharge is the source gas to process the substrate flows into the processing space,
A substrate processing method in which power is not applied to the induction coil surrounding the discharge space while the ozone passes through the discharge space . The first processing step includes
The substrate processing method according to claim 1 , further comprising: supplying water vapor to the discharge space, and processing the substrate by flowing the water vapor into the processing space.

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