JPH04109524U - plasma generator - Google Patents

Abstract

(57) [Summary] [Purpose] O in contact with a quartz plate heated by plasma
Prevents ring deterioration due to heat. [Structure] A processing chamber 3 is formed by a processing chamber container 23 and a quartz plate 46 that airtightly closes the upper surface of the processing chamber container, and a plasma plasma is connected to a waveguide unit 4 that introduces microwaves into the processing chamber. The generator includes a donut-shaped holder plate 33 with the quartz plate 46 attached to the processing chamber side, and a donut-shaped presser plate 43 attached to the holder plate.
A sealing O-ring 44 is provided between the holder plate and the quartz plate, a required number of ventilation holes 48 are provided in the holding plate to communicate the inner circumferential surface and the outer circumferential surface, and the quartz plate is supplied from above. The cooling gas is allowed to flow out from the ventilation hole, and a cooling pipe 41 is provided in the holder plate along the periphery of the quartz plate. Cooling gas flows along the surface of the quartz plate and flows out through the ventilation holes to cool the quartz plate, and further cools the O-ring by flowing a refrigerant through the cooling pipe. By cooling the quartz plate and the O-ring, the O-ring is prevented from overheating and deterioration due to heat is suppressed.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention generates plasma by introducing microwaves into the wafer processing chamber. A cooling structure for a plasma generator, particularly a quartz plate defining a processing chamber of the plasma generator. It is related to construction.

0002

[Conventional technology]

One type of semiconductor manufacturing equipment uses plasma to process the surface of wafers. There is also a method in which plasma generation is performed by introducing microwaves into the wafer processing chamber.

0003 FIG. 2 shows the entire microwave plasma generator.

0004 A microwave generation unit 2 is provided on the upper part of the frame 1. A wafer processing chamber 3 is provided below the cut 2. The microwave generation unit The microwave generated in the chamber 2 is transmitted to the wafer processing chamber 3 by a waveguide unit 4. It's like being guided.

[0005] The waveguide unit 4 includes a waveguide 5 having a flat cross section, a matching device 6, and a circular cross section. It consists of a circular waveguide 7 etc. having a planar shape.

[0006] A conventional plasma generator will be explained with reference to FIG.

[0007] A lower container 9 is provided on the base 8, and a ring plate 10 is connected to the lower container 9. A hole reflecting plate 11 is provided, a trunk ring 12 is provided on the ring plate 10, and the trunk ring 12 is provided on the ring plate 10. A quartz plate 13 is attached to the ring 12. Moreover, a waveguide is provided at the upper end of the body ring 12. Said circular waveguide 7 of unit 4 is installed. The lower container 9 and the ring The joints, such as the joint with the rate 10 and the joint between the quartz plate 13 and the body ring 12, are heat-resistant. O-rings 14, 15, 16 are provided, and the inside of the processing chamber 3 is airtight. Ru. Further, a required number of reaction gas introduction holes 18 are bored around the body ring 12, as shown in FIG. The reaction gas is supplied from a reaction gas supply source (not shown).

[0008] The base 8 is provided with a wafer mounting table 19, and the wafer mounting table 19 is used for processing. A wafer 20 to be processed is placed thereon.

[0009] Microwaves are guided into the processing chamber 3 via the waveguide unit 5 . Guidance The input microwave excites the reaction gas supplied into the processing chamber 3, Plasma is generated between the lower surface of the quartz plate 13 and the upper surface of the reflecting plate 11. This occurrence The neutral active species of the plasma that has passed through the porous reflector 11 causes the wafer to C20 surface treatment is performed.

0010

[Problem that the idea aims to solve]

As mentioned above, in order to make the processing chamber 3 airtight, the quartz plate 13 and the body ring 12 are joined together. An O-ring is provided at the joint between the quartz plate 13 and other components such as the quartz plate 13. Said The quartz plate 13 defines the processing chamber 3, and when the microwave passes through the quartz plate 13, the dielectric The temperature rises due to heat generation due to body loss and heating due to collisions of electrons and ions from the plasma. It becomes warm. For this reason, the O-ring 14 is heated by the quartz plate 13 and deteriorates.

[0011] In the microwave plasma generator described above, the means for cooling the quartz plate 13 is particularly The O-ring 14 was not provided, and the O-ring 14 was replaced as appropriate based on the state of deterioration.

0012 However, this heat-resistant O-ring 14 is very expensive and must be replaced frequently. If the There was a problem in that the operating rate decreased.

[0013] In view of this situation, the present invention is designed to cool the quartz plate and delay the deterioration of the O-ring. The aim is to reduce running costs and improve operating rates.

[0014]

[Means to solve the problem]

The present invention uses a processing chamber container and a quartz plate that airtightly closes the upper surface of the processing chamber container. A processing chamber is formed, and a waveguide unit for introducing microwaves into the processing chamber is connected. In the plasma generator, a donut-shaped holder with the quartz plate attached to the processing chamber side was used. by the holder plate and the donut-shaped presser plate attached to the holder plate. A sealing O-ring is provided between the holder plate and the quartz plate, and the A required number of ventilation holes are provided on the quartz plate to communicate the inner circumferential surface and the outer circumferential surface, and For example, an inert cooling gas such as nitrogen or argon is supplied from the ventilation hole. It is designed to allow water to flow out, and a cooling pipe is installed in the holder plate around the quartz plate. It was placed along the line.

[0015]

[Effect]

Cooling gas supplied from above the quartz plate is discharged from around the top surface of the quartz plate. By doing so, the cooling gas flows along the entire top surface of the quartz plate, effectively cooling the quartz plate. do. By cooling the quartz plate, heating of the O-ring in contact with the quartz plate is prevented, and furthermore, By circulating a refrigerant through the cooling pipe, the O-ring can be cooled, reducing the possibility of deterioration due to heating of the O-ring. This can prevent

[0016]

【Example】

Hereinafter, one embodiment of the present invention will be described based on the drawings.

[0017] In FIG. 1, the wafer placement table is omitted. A donner is placed at the upper end of the processing chamber container 23. The top cover 24 in the form of a disk is airtightly attached, and a ring is formed on the top surface of the top cover 24 concentrically with the top cover 24. The seat 25 is fixed airtight. A cylindrical space holder 26 is installed on the lower surface of the upper lid 24. Install. The space holder 26 has a flange 27 at its lower end that projects toward the center. There is. The inner diameters of the space holder 26, the upper lid 24, and the ring seat 25 are the same diameter. A spacer 28 is attached to the cylindrical surface formed by the space holder 26, the upper cover 24, and the ring seat 25. , 29, 30, and 31. The spacers 28, 29, 30, 31 are The lengths in the axial direction are different. Moreover, the spacers 28, 29, 30, 31 The stacked length in the axial direction is slightly lower than the upper end surface of the ring seat 25. So Then, place the porous reflector 32 between the spacers and the spacer and the quartz plate holder plate 3. 3 or between the spacer and the collar 27.

[0018] The holder plate 33 having substantially the same shape as the ring seat 25 is fixed to the upper surface of the ring seat 25. wear it. A stepped portion 34 for holding the quartz plate 46 is formed on the inner diameter side of the holder plate 33. Furthermore, a groove 35 is carved in the bottom surface of the stepped portion 34.

[0019] An annular groove 36 is carved on the bottom surface of the holder plate 33, and the annular groove 36 and the holder plate A required number of communication holes 37 communicating with the inner circumferential surface of the seat 33 are bored along the radial direction. Further, a guide hole 38 bored from the outer peripheral surface side of the holder plate 33 is communicated with the annular groove 36. The guide hole 38 is connected to a reaction gas supply source (not shown) via a supply pipe 39. are doing.

[0020] O-rings are provided on the upper surface of the ring seat 25 and on the inner and outer diameter sides of the ring groove 36, respectively. rings 40, 40 are provided to airtightly seal the annular groove 36.

[0021] A cooling pipe 41 is buried on the upper surface of the holder plate 33 and along the stepped portion 34. Ru. Further, a seal 42 is provided between the cooling pipe 41 and the stepped portion 34.

[0022] The quartz plate 46 has its circumferential end fitted into the stepped portion 34, and the quartz plate 46 has its peripheral end fitted into the stepped portion 34, and It is held between a presser plate 43 fixed to the upper surface and a holder plate 33. . Further, in the groove 35, there is an O-ring 44 for sealing, and a synthetic resin clip for holding the quartz plate. The cushion ring 45 is buried, and the upper peripheral edge of the quartz plate 46 and the presser plate 43 are A cushion ring 47 is interposed between them.

[0023] A plurality of ventilation holes 48 are bored in the holding plate 43 at a required pitch in the radial direction. ing. A circular waveguide 49 is fixed to the holding plate 43. The circular waveguide 4 A nitrogen gas supply pipe 50 is connected to the upper surface of 9, and the nitrogen gas supply pipe 50 is not shown. Connected to a nitrogen gas source.

[0024] The action will be explained below.

[0025] The microwave generated by the microwave generation unit 2 is guided to the waveguide unit 4. and introduced into the processing chamber 3. Through the supply pipe 39, the annular groove 36, and the communication hole 37 A reaction gas is supplied into the processing chamber 3. is supplied into the processing chamber 3 by the microwave. The reactant gas is excited, and plasma is formed between the lower surface of the quartz plate 46 and the upper surface of the reflecting plate 32. generate ma. Due to the neutral active species that passed through the porous reflector 32 of this plasma, A wafer (not shown) is then processed. The quartz plate 46 allows microwaves to pass through it. Heat is generated due to dielectric loss when It gets heated.

[0026] On the other hand, during operation, the inside of the circular waveguide 49 passes through the nitrogen gas supply pipe 50. Nitrogen gas at approximately room temperature is supplied, and the nitrogen gas is exhausted to the outside through the ventilation hole 48. Served. During this nitrogen gas distribution process, nitrogen gas flows from the surface of the quartz plate 46. The heat is removed and the quartz plate 46 is cooled.

[0027] Further, the ventilation holes 48 are provided near the surface of the quartz plate 46 and along the periphery thereof. There is no stagnation in the flow of the nitrogen gas, and cooling is effectively performed over the entire surface of the quartz plate 46. be exposed.

[0028] Furthermore, a refrigerant such as water is made to flow through the cooling pipe 41 through the holder plate 33. The O-ring 40 is cooled.

[0029] Since the quartz plate 46 itself is cooled with nitrogen gas, the O-ring 44 is exposed to plasma. In addition, the O-ring 44 itself also flows through the cooling pipe 41. It is cooled by a refrigerant.

[0030] By cooling the quartz plate 46 and cooling the O-ring 44 itself, the O-ring 44 is heated. This prevents deterioration of the O-ring 44 and extends its life.

[0031] Note that the reflective plate 32 is sandwiched between any of the spacers 28, 29, 30, and 31. By selecting the clamping point, the position of the reflector plate 32 can be changed. By changing the position of the reflector 32, the optimum wafer and reflection can be achieved according to the wafer processing conditions. It can be the distance of the shooting plate 32.

[0032]

[Effect of the idea]

As described above, according to the present invention, the flow of nitrogen gas without stagnation effectively The quartz plate can be cooled, and deterioration of the O-ring in contact with the quartz plate can be suppressed. Also, O By cooling the O-ring through a cooling pipe provided around the O-ring, the O-ring deterioration can be further suppressed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an overall view of a plasma generator in which the embodiment is implemented.

FIG. 3 is a sectional view showing a conventional example.

[Explanation of symbols]

2 Microwave generation unit 3 Processing room 4 Waveguide unit 23 Processing chamber container 33 Holder plate 43 Presser plate 46 Quartz plate 48 Ventilation hole

Claims (2)

[Scope of utility model registration request] 1. A plasma generation device in which a processing chamber is formed by a processing chamber container and a quartz plate that airtightly closes the upper surface of the processing chamber container, and a waveguide unit for introducing microwaves into the processing chamber is connected. In this step, the quartz plate is held between a donut-shaped holder plate attached to the processing chamber side and a donut-shaped holding plate attached to the holder plate, and a sealing O-ring is provided between the holder plate and the quartz plate; A plasma generating device characterized in that the presser plate is provided with a required number of ventilation holes that communicate the inner peripheral surface and the outer peripheral surface, and the cooling gas supplied from above the quartz plate is made to flow out from the ventilation holes. 2. The plasma generating device according to claim 1, wherein a cooling pipe is provided on the holder plate along the periphery of the quartz plate.