Plasma processing system and plasma processing method

Abstract

To provide a plasma processing system and a plasma processing method capable of suppressing deposition of a solid product in a pump for sucking a gas discharged from a gas discharge source.SOLUTION: A plasma processing device 1 includes: a first pipe body 11 into which a gas discharged from a film forming device 3 flows from one end side in a pipe axis direction; an etchant supply unit 51 that supplies an etchant gas into the first pipe body 11; a second pipe body 12 whose one end portion in the pipe axis direction is connected to the other end portion in the pipe axis direction of the first pipe body 11 and into which the gas and the etchant gas flow from the first pipe body 11; and a plasma generation unit 13 that generates plasma in the second pipe body 12 by generating a high-frequency electromagnetic field in the second pipe body 12 in a state where the gas and the etchant gas are present in the second pipe body 12. Then, a plasma-treated gas present in the second pipe body 12 is sucked by a pump 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plasma processing system and a plasma processing method.

Background Art

[0002] In a semiconductor manufacturing apparatus that performs processes such as film formation and etching, an exhaust pump for exhausting the gas discharged from the chamber to the outside has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when an exhaust pump as described in Patent Document 1 is used in a semiconductor manufacturing apparatus, a solid product generated from a substance contained in the gas discharged from the chamber, or a solid product generated in the chamber and then discharged may accumulate inside the exhaust pump, and there is a risk that the exhaust performance of the exhaust pump may deteriorate. Therefore, an apparatus or method for suppressing the deposition of components contained in the gas discharged from the chamber into the exhaust pump has been demanded.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a plasma processing system and a plasma processing method capable of suppressing the deposition of solid products in a pump that sucks gas discharged from a gas discharge source.

Means for Solving the Problems

[0006] To achieve the above object, a plasma processing system according to the present invention is A plasma processing system interposed between a gas discharge source that discharges gas and a pump that sucks the gas, and performs plasma processing on the gas discharged from the gas discharge source, a first tubular body that is tubular and into which the gas discharged from the gas discharge source flows from one end side in the tube axis direction, an etchant supply unit that supplies an etchant gas into the first tubular body, a second tubular body that is tubular and has one end portion in the tube axis direction connected to the other end portion in the tube axis direction of the first tubular body, and into which the gas and the etchant gas flow from the first tubular body, a plasma generation unit that generates plasma in the second tubular body by generating a high-frequency electromagnetic field in the second tubular body while the gas and the etchant gas are present in the second tubular body, and the plasma-treated gas present in the second tubular body is sucked by the pump from the other end side in the tube axis direction of the second tubular body.

Advantages of the Invention

[0007] According to the present invention, the gas discharged from the gas discharge source is mixed with the etchant gas inside the first tubular body and flows into the second tubular body, and after plasma processing is performed on the gas and the etchant gas inside the second tubular body, it is sucked by the pump. As a result, the substances contained in the gas discharged from the gas discharge source are decomposed in the plasma inside the second tubular body and changed into substances that are less likely to form solid products, and then are sucked by the pump, so that the deposition of solid products in the pump can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The plasma processing apparatus according to the present invention is interposed between a gas discharge source that discharges gas and a pump that sucks gas, and performs plasma processing on the gas discharged from the gas discharge source. This plasma processing apparatus is tubular, and includes a first tubular body into which the gas discharged from the gas discharge source flows from one end side in the tube axis direction, an etchant supply unit that supplies etchant gas into the first tubular body, and a second tubular body that is tubular and has one end portion in the tube axis direction connected to the other end portion in the tube axis direction of the first tubular body, and into which the gas and the etchant gas flow from the first tubular body, and a plasma generation unit that generates plasma in the second tubular body by applying a high-frequency electromagnetic field to the gas and the etchant gas supplied into the second tubular body. Then, the gas after plasma processing existing in the second tubular body is sucked by the pump from the other end side in the tube axis direction of the second tubular body.

[0010] As shown in FIG. 1, the plasma processing system 100 according to the present embodiment is used together with a film forming apparatus 3 and a pump 4. The film forming apparatus 3 is a film forming apparatus such as a CVD (Chemical Vapor Deposition) apparatus or a sputtering apparatus, and is a gas discharge source that discharges the source gas introduced into a film forming chamber (not shown) for film forming through an exhaust pipe L1 led out of the film forming chamber. The film forming apparatus 3 includes, for example, a CVD apparatus that introduces SiH4 gas and O2 gas into the film forming chamber and forms a SiO2 film on a wafer (not shown) disposed in the film forming chamber. In this case, the film forming apparatus 3 discharges the SiH4 gas, O2 gas, and SiO2 particles existing in the film forming chamber to the outside of the film forming chamber through the exhaust pipe L1.

[0011] The pump 4 is a dry pump such as a turbo molecular pump, a cryopump, etc. The pump 4 sucks the processed gas discharged from the film forming apparatus 3 and plasma - processed by the plasma processing system 100, and exhausts it to the exhaust pipe L2. The other end of the exhaust pipe L2 opposite to the end connected to the pump 4 is connected to the decontamination facility 5 for removing harmful substances contained in the gas, and the gas from which the harmful substances have been removed by the decontamination facility 5 is discharged outside the decontamination facility 5 through the exhaust pipe L3.

[0012] The plasma processing system includes a plasma processing apparatus 1, a trap unit 2 disposed downstream of the plasma processing apparatus 1, an etchant supply unit 51, and a dilution gas supply unit 52. The plasma processing apparatus 1 includes a first pipe body 11, a second pipe body 12, a plasma generation unit 13, and pipe body connection parts 14, 15, 16. As shown in FIGS. 2 and 3, the first pipe body 11 is tubular, and the gas discharged from the film forming apparatus 3 on one end side in the direction of the pipe axis J1, that is, the +Z direction side, flows inside. Further, the first pipe body 11 has a tubular main part 111 and outer flange parts 112, 113 that project away from the pipe axis J1 along the direction orthogonal to the pipe axis J1 from both ends in the Z - axis direction of the main part 111. In the first pipe body 11, gas introduction parts 181, 182 for introducing the etchant gas and the dilution gas inside, and flow rate adjustment parts 171, 172 for adjusting the flow rates of the etchant gas and the dilution gas flowing through the gas introduction parts 181, 182 are arranged. The flow rate adjustment parts 171, 172 are, for example, mass flow controllers. The end of the first pipe body 11 on the +Z direction side is connected via the pipe body connection part 14 to the end of the exhaust pipe L1 opposite to the film forming apparatus 3 side. The pipe body connection part 14 includes an annular sealing member (not shown) interposed between the +Z - direction side surface of the outer flange part 112 of the first pipe body 11 shown in FIGS. 2 and 3 and the end of the exhaust pipe L1, and a holder (not shown) that holds the outer flange part 112 of the first pipe body 11 and the end of the exhaust pipe L1 in a state where they are in contact with each other via the sealing member.

[0013] Returning to FIG. 1, the etchant supply unit 51 supplies etchant gas into the second pipe body 12. Examples of the etchant gas include gases containing at least one of NF3, CF4, and COF2. The etchant supply unit 51 includes a gas storage unit 511 that stores the etchant gas, and a supply pipe 512 through which the etchant gas is supplied from the gas storage unit 511. The end of the supply pipe 512 on the side opposite to the gas storage unit 511 side is connected to the aforementioned gas introduction unit 181 via a flow rate adjustment unit 171.

[0014] The dilution gas supply unit 52 supplies a dilution gas for diluting the etchant gas into the second pipe body 12. Examples of the dilution gas include N2. The dilution gas supply unit 52 includes a gas storage unit 521 that stores the dilution gas, and a supply pipe 522 through which the dilution gas is supplied from the gas storage unit 521. The end of the supply pipe 522 on the side opposite to the gas storage unit 521 side is connected to the aforementioned gas introduction unit 182 via a flow rate adjustment unit 172.

[0015] As shown in Fig. 2, the second pipe body 12 is tubular, and one end in the direction of the pipe axis J2, that is, the end on the +Z direction side, is connected to the other end in the direction of the pipe axis J2 of the first pipe body 11, that is, the end on the -Z direction side. Gas and etchant gas flow into the second pipe body 12 from the first pipe body 11. Here, the pipe axis J2 of the second pipe body 12 is arranged to coincide with the pipe axis J1 of the first pipe body 11. The second pipe body 12 includes a tubular main part 121, an introduction part 122 which is tubular and is continuously and integrally connected to the end on the +Z direction side of the main part 121 to introduce gas and etchant gas from the first pipe body 11 into the main part 121, and a discharge part 123 which is continuously and integrally connected to the end on the -Z direction side of the main part 121 to discharge the gas after plasma treatment from the main part 121 to the pump 4. Further, the second pipe body 12 has outer flange parts 124 and 125 that project in a direction away from the pipe axis J1 along a direction orthogonal to the pipe axis J2 from the end on the +Z direction side of the introduction part 122 and the end on the -Z direction side of the discharge part 123, respectively. The end on the +Z direction side of the second pipe body 12 is connected to the end on the -Z direction side of the first pipe body 11 via a pipe connection part 15. The pipe connection part 15 includes an annular sealing member 153 interposed between the surface on the -Z direction side of the outer flange part 113 of the first pipe body 11 and the surface on the +Z direction side of the outer flange part 124 of the second pipe body 12, and holders 151 and 152 that hold the outer flange part 113 of the first pipe body 11 and the outer flange part 124 of the second pipe body 12 in a state where the outer flange part 113 of the first pipe body 11 and the outer flange part 124 of the second pipe body 12 are in contact with each other via the sealing member 153. Also, as shown in Fig. 1, the end on the -Z direction side of the second pipe body 12 is connected to the end of an introduction pipe 23 (to be described later) of the trap unit 2 via a pipe connection part 16. The pipe connection part 16 includes an annular sealing member (not shown) interposed between the surface on the -Z direction side of the outer flange part 125 of the second pipe body 12 shown in Figs. 2 and 3 and the end of the introduction pipe 23, and a holder (not shown) that holds the outer flange part 125 of the second pipe body 12 and the end of the introduction pipe 23 in a state where the outer flange part 125 of the second pipe body 12 and the end of the introduction pipe 23 are in contact with each other via the sealing member.

[0016] The plasma generation unit 13 generates plasma in the second pipe body 12 by generating a high-frequency electromagnetic field in the second pipe body 12 while gas and an etchant gas are present in the second pipe body 12. The plasma generation unit 13 includes a high-frequency power source 133 that generates high-frequency power, an induction coil 131 that is electrically connected to the high-frequency power source 133 and is arranged to surround the second pipe body 12, and a permanent magnet 132 that faces the outer wall of the second pipe body 12 and is arranged inside the induction coil 131. With gas and an etchant gas present in the second pipe body 12, the high-frequency power generated by the high-frequency power source 133 is supplied to the induction coil 131, thereby generating a high-frequency electromagnetic field in the second pipe body 12. The high-frequency power source 133 supplies alternating current power with a high frequency (for example, a frequency of 13.56 MHz) to the induction coil 131. Further, the plasma generation unit 13 includes a coil support portion 135 that supports the induction coil 131, a protection member 134 interposed between the outer wall of the second pipe body 12 and the permanent magnet 132, a base plate 138 to which the high-frequency power source 133 is mounted, a fixing member 137 for fixing the base plate 138 to the first pipe body 11 and the second pipe body 12, and a housing 136 in which the induction coil 131 and the permanent magnet 132 are arranged inside and fixed to the high-frequency power source 133. The permanent magnet 132 is arranged to increase the density of the plasma generated in the second pipe body 12 and to suppress the diffusion of the plasma to the side wall of the second pipe body 12 due to the magnetic field confinement effect caused by the magnetic field generated by the permanent magnet 132.

[0017] Returning to FIG. 1, the trap unit 2 is interposed between the end of the second pipe body 12 on the side opposite to the first pipe body 11 and the pump 4, and adsorbs the solid products contained in the gas discharged from the second pipe body 12. The trap unit 2 includes a housing 21, a trap portion 22 disposed inside the housing 21 for adsorbing the solid products contained in the gas flowing into the housing 21 from the second pipe body 12, and a cooling portion 25 for cooling the trap portion 22. Further, the trap unit 2 includes an introduction pipe 23 for introducing the gas after plasma treatment discharged from the second pipe body 12 into the housing 21, and a discharge pipe 24 communicating with the inside of the housing 21 and connected to the pump 4. The housing 21 has a box shape, and the end of the second pipe body 12 on the side opposite to the first pipe body 11 is connected to a first through hole 21a formed through a part of the peripheral wall via the introduction pipe 23, and the gas discharged from a second through hole 21b formed at a position different from the first through hole 21a in the peripheral wall is sucked by the pump 4 through the discharge pipe 24.

[0018] It is assumed that the film forming apparatus 3 according to the present embodiment is a CVD apparatus for forming a SiO2 thin film using, for example, SiH4 gas and O2 gas. Further, it is assumed that the etchant supply unit 51 supplies NF3 gas and the dilution gas supply unit 52 supplies N2 gas. In this case, from the film forming apparatus 3, SiO2 particles are discharged to the first pipe body 11 through the exhaust pipe L1 together with SiH4 gas and O2 gas. Then, inside the second pipe body 12, the gas containing SiH4 gas, O2 gas, and SiO2 particles flowing in from the exhaust pipe L1 is mixed with NF3 gas supplied from the etchant supply unit 51 and N2 gas supplied from the dilution gas supply unit 52 inside the first pipe body 11 and then flows into the second pipe body 12. Then, inside the second pipe body 12, SiH4 and SiO2 particles are decomposed by fluorine radicals present in the plasma, and the substances contained in the gas change to SiF4, O2, and N2 in which solid products are difficult to generate. Then, the gas containing SiF4, O2, and N2 flows into the trap unit 2. The trap unit 2 further removes the SiO2 particles contained in the gas by adsorbing the SiO2 particles contained in the inflowing gas to the trap portion 22. Then, the gas discharged from the trap unit 2 is sucked by the pump 4.

[0019] As described above, according to the plasma processing system 100 according to the present embodiment, the gas discharged from the film forming apparatus 3 is mixed with the etchant gas inside the first pipe body 11 and flows into the second pipe body 12, and the gas and the etchant gas are subjected to plasma processing inside the second pipe body 12, and then sucked by the pump 4. Thereby, the substances contained in the gas discharged from the film forming apparatus 3 are decomposed in the plasma inside the second pipe body 12 to change into substances that are less likely to generate solid products, and then sucked by the pump 4, so that the deposition of solid products in the pump 4 can be suppressed. Further, the deposition of solid products on the inner walls of the exhaust pipe L1 from the film forming apparatus 3 to the pump 4, the first pipe body 11, and the exhaust pipe L2 after the pump 4 can also be suppressed.

[0020] In addition, the plasma generation unit 13 according to the present embodiment has a permanent magnet 132 disposed inside the induction coil 131 and facing the outer wall of the second pipe body 12. Thereby, the density of the plasma generated inside the second pipe body 12 can be increased, so that the density of the radicals of the elements constituting the substances contained in the etchant gas present in the plasma can be increased. Therefore, the efficiency of the plasma processing for the gas flowing from the first pipe body 11 into the second pipe body 12 can be increased.

[0021] Furthermore, the plasma processing system 100 according to the present embodiment includes a trap unit 2 interposed between the second pipe body 12 and the pump 4 and adsorbing the solid products contained in the gas discharged from the second pipe body 12. Thereby, the solid products contained in the gas discharged from the second pipe body 12 are removed, so that the deposition of solid products in the pump 4 can be suppressed.

[0022] As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the configurations of the above-described embodiments. The plasma generation unit may generate, for example, microwaves. In this case, the second pipe body 12 may have a dielectric window disposed on its side wall. Then, the plasma generation unit may generate plasma inside the second pipe body 12 by introducing microwaves into the inside of the second pipe body 12 through the dielectric window in a state where the gas discharged from the film forming apparatus 3 and the etchant gas are present inside the second pipe body 12.

[0023] In the embodiment, an example in which the gas discharge source is the film forming apparatus 3 has been described. However, the present invention is not limited to this, and other types of apparatuses that discharge gas including a solid generation unit such as an etching apparatus may be used.

[0024] As described above, the embodiments and modified examples of the present invention have been explained. However, the present invention is not limited to these. The present invention includes those in which the embodiments and modified examples are appropriately combined, and those in which appropriate changes are made thereto.

Industrial Applicability

[0025] The present invention is suitable for suppressing the deposition of solid products on the exhaust pipes and pumps of semiconductor manufacturing apparatuses such as semiconductor film forming apparatuses and semiconductor etching apparatuses.

Explanation of Reference Numerals

[0026] 1: Plasma processing apparatus, 2: Trap unit, 3: Film forming apparatus, 4: Pump, 5: Decontamination equipment, 11: First pipe body, 12: Second pipe body, 13: Plasma generation part, 14, 15, 16: Pipe body connection part, 21, 136: Housing, 21a: First through hole, 21b: Second through hole, 22: Trap part, 23: Introduction pipe, 24: Discharge pipe, 25: Cooling part, 51: Etchant supply part, 52: Dilution gas supply part, 100: Plasma processing system, 111, 121: Main part, 112, 113, 124, 125: Outer flange part, 122: Introduction part, 123: Discharge part, 131: Induction coil, 132: Permanent magnet, 133: High frequency power source, 134: Protection member, 135: Coil support member, 137: Fixed member, 138: Base plate, 171, 172: Flow rate adjustment part, 181, 182: Gas introduction part, 511, 521: Gas storage part, 512, 522: Supply pipe, L1, L2, L3: Exhaust pipe

Claims

1. A plasma processing system interposed between a gas discharge source that discharges gas and a pump that sucks the gas, and performing plasma processing on the gas discharged from the gas discharge source, a first tubular body that is tubular and into which the gas discharged from the gas discharge source flows from one end side in the tube axis direction, an etchant supply unit that supplies an etchant gas into the first tubular body, a second tubular body that is tubular and has one end portion in the tube axis direction connected to the other end portion in the tube axis direction of the first tubular body, and into which the gas and the etchant gas flow from the first tubular body, a plasma generation unit that generates plasma in the second tubular body by generating a high-frequency electromagnetic field in the second tubular body while the gas and the etchant gas are present in the second tubular body, wherein the gas after the plasma processing present in the second tubular body is sucked by the pump from the other end side in the tube axis direction of the second tubular body, a plasma processing system.

2. The plasma generation unit includes a high-frequency power source that generates high-frequency power, and an induction coil that is electrically connected to the high-frequency power source, is arranged to surround the second tubular body, and generates a high-frequency electromagnetic field in the second tubular body by supplying the high-frequency power generated by the high-frequency power source while the second tubular body is filled with the gas and the etchant gas, and a permanent magnet that faces the outer wall of the second tubular body and is arranged inside the induction coil. The plasma processing system according to Claim 1.

3. further includes a trap unit that is interposed between the other end portion of the second tubular body and the pump and adsorbs solid products contained in the gas discharged from the second tubular body, wherein the trap unit is box-shaped, has the other end portion in the tube axis direction of the second tubular body connected to a first through hole formed through a part of the peripheral wall, and a housing from which the gas discharged from a second through hole formed at a position different from the first through hole in the peripheral wall is sucked by the pump, a trap portion that is arranged inside the housing and adsorbs solid products contained in the gas flowing into the housing from the second tubular body, and a cooling unit that cools the trap portion. The plasma processing system according to Claim 1 or 2.

4. The gas contains SiH ３ and The etchant gas is NF ３ , CF ４ and COF ２ and includes at least one of them. The plasma processing system according to Claim 1 or 2.

5. A plasma treatment method that is interposed between a gas discharge source that discharges gas and a pump that sucks the gas, and that performs plasma treatment on the gas discharged from the gas discharge source, a step of supplying an etchant gas into a first tubular body that is tubular and into which the gas discharged from the gas discharge source flows from one end side in the tube axis direction; a step of generating plasma in a second tubular body that is tubular and has one end portion in the tube axis direction connected to the other end portion of the first tubular body in the tube axis direction, by generating a high-frequency electromagnetic field in the second tubular body while the gas flowing in from the first tubular body and the etchant gas are present in the second tubular body; a step of sucking, by the pump, the gas after plasma treatment present in the second tubular body from the other end side in the tube axis direction of the second tubular body, and a plasma treatment method.

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