JPH04109525U - plasma generator - Google Patents

Abstract

(57) [Summary] [Purpose] This is a plasma generator that generates plasma using microwaves, and the position of a quartz discharge plate can be changed. [Structure] A processing chamber 3 is formed by a processing chamber container 23 and a quartz discharge plate 13 that airtightly closes the upper surface of the processing chamber container.
In a plasma generation device in which microwaves are introduced into the processing chamber and plasma is generated on the side of the quartz discharge plate processing chamber, the quartz discharge plate 13 is connected to the processing chamber vessel via a quartz discharge plate holder plate 28. 23, and a ring seat can be interposed between the quartz discharge plate holder plate and the processing chamber container, and by selecting the presence or absence of the ring seat, the thickness of the ring seat, and the number of ring seats, the quartz discharge plate and the The distance between the wafer, that is, the plasma and the wafer is changed.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention generates plasma by introducing microwaves into the wafer processing chamber. Define a plasma generation device, especially a processing chamber of the plasma generation device, and process a wafer. The present invention relates to a structure for adjusting the position of a quartz discharge plate, which affects the state of the discharge plate.

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. 3 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 rectangular 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 discharge plate 13 is attached to the ring 12. Further, at the upper end of the trunk ring 12, a guide is provided. The circular waveguide 7 of the wavetube unit 4 is attached. The lower container 9 and phosphorus At the joints such as the joint with the quartz discharge plate 13 and the trunk ring 12, etc. is provided with heat-resistant O-rings 14, 15, and 16, and the inside of the processing chamber 3 is kept airtight. It has become. Further, a required number of reaction gas introduction holes 18 are bored around the body ring 12. and a reaction gas (not shown) is supplied.

[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 is reflected by the porous reflection plate 11, and is reflected by the quartz discharge plate 13. The reactive gas between the porous reflectors 11 is excited to generate plasma. Said porous reflection Even without the plate 11, it is possible to generate plasma by being reflected by the wafer 20. is not as stable as when a porous reflector is installed. However, the porous reflector 11 is made of metal. If possible, it is better not to have the porous reflector 11 in consideration of contamination from the inside. This occurred The surface treatment of the wafer 20 is performed by plasma.

0010

[Problem that the idea aims to solve]

When wafers are processed using plasma, the distance between the plasma and the wafer is long. When the temperature decreases, the ions disappear, and the etching becomes radical-based, causing the plasma and wafer to When the distance between the ion and the etchant becomes close, the etching mainly consists of ions. Therefore, the wafer and The distance to the plasma, that is, the distance between the wafer and the quartz discharge plate, depends on the processing state of the wafer. It has a big impact.

[0011] Therefore, in order to achieve the desired etching speed, uniformity of processing, etc., processing conditions must be For example, select the optimal quartz discharge plate and wafer according to the type of reaction gas, gas pressure, and gas flow rate. The distance from -ha must be selected.

0012 However, in the conventional plasma generator described above, it is difficult to adjust the position of the quartz discharge plate. The distance between the quartz discharge plate and the wafer can be changed according to the processing conditions. I couldn't let it go.

[0013] In view of these circumstances, the present invention has been developed to allow the position of the quartz discharge plate to be easily changed. This is what we are trying to do.

[0014]

[Means to solve the problem]

The present invention consists of a processing chamber container and a quartz discharge plate that airtightly closes the upper surface of the processing chamber container. A processing chamber is formed, and microwaves are introduced into the processing chamber to process the quartz discharge plate. In a plasma generator designed to generate plasma on the chamber side, the quartz discharge The plate is attached to the processing chamber container via a quartz discharge plate holder plate, and A ring seat can be interposed between the quartz discharge plate holder plate and the processing chamber container. It is characterized by:

[0015]

[Effect]

Cases with and without a ring seat interposed between the quartz discharge plate holder plate and the processing chamber container If the thickness of the ring seat is changed, or the number of ring seats is changed, the stone The distance between the discharge plate and the wafer changes, and the distance between the plasma and the wafer also changes. . Therefore, the distance between the plasma and the wafer can be determined by selecting the intervening ring seat and the mode of intervening ring seat. It becomes possible to bring the distance to an appropriate state.

[0016]

【Example】

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

[0017] Note that the wafer placement table is omitted in FIG.

[0018] A donut-shaped upper lid 24 is airtightly attached to the upper end of the processing chamber container 23. Ring seats 25, 26, and 27 are airtightly and removably fixed to the upper surface of 4 concentrically with the upper lid 24. do. A donut-shaped quartz discharge plate holder plate 28 is airtightly placed on the upper surface of the ring seat 27. and removably attached to the quartz discharge plate holder plate 28 and the quartz discharge plate holder. The quartz discharge plate is held down by the quartz discharge plate holding ring 29 attached to the top surface of the plate 28. Hold 13.

[0019] The upper lid 24 has a flange 28 at its lower end that protrudes toward the center. , the inner diameters of the ring seats 25, 26, 27 are the same diameter, and the inner diameters of the ring seats 25, 26, 27 are the same. , 27, a cylindrical space made of quartz is placed on the cylindrical surface formed by the quartz discharge plate holder plate 28. Fit the sensors 30, 31, 32, and 33.

[0020] The ring seats 25, 26, and 27 each have a different thickness and a fitting part that protrudes from the lower surface. A fitting recess is formed on the convex portion and the upper surface, and the fitting convex portion of the ring seats 25, 26, 27 and the ring seat 25 , 26 have the same shape. Further, a ring seat 2 is also provided on the upper surface of the upper lid 24. Recesses that fit with the fitting convex portions 5, 26, and 27 are formed, and the quartz discharge plate holder plate The lower surface of the plate 28 is formed with a protrusion that loosely fits into the fitting recess of the ring seat 27. Change The upper and lower surfaces of the upper lid 24 and the ring seats 25, 26, and 27 are respectively The O-ring 34 is buried, and the ring seats 25, 26, 27, quartz discharge plate Airtightness is maintained in the polymerized state of the holder plate 28.

[0021] An annular groove 35 is carved from the lower surface side at the step boundary of the quartz discharge plate holder plate 28. A guide hole 36 bored from the outer circumferential surface communicates with the annular groove 35. Also, the guide hole The section 36 is connected to a reaction gas supply source (not shown) via a supply pipe 37. The quartz beam The convex portion of the electric board holder plate 28 is provided with an inner peripheral surface of the convex portion at a required pitch along the circumference. A communication hole 38 communicating with the outer peripheral surface is bored.

[0022] The length of the cylindrical spacers 30, 31, 32, 33 in the axial direction is the same as that of the ring seat 25. , 26, 27, correspond to the thickness of the quartz discharge plate holder plate 28, and each cylinder A stepped portion 39 is formed at the upper end of the outer peripheral surface of the spacers 30, 31, 32, 33, and each The upper end surfaces of the cylindrical spacers 30, 31, 32, and 33 are formed in half along the circumference at the required pitch. A groove 40 extending in the radial direction is cut.

[0023] Thus, the inside of the processing chamber and the supply pipe 37 are connected to the groove 40, the stepped portion 39, and the communication hole 3. 8, communicated via annular groove 35 and guide hole 36.

[0024] A cooling pipe 41 is embedded around the opening of the quartz discharge plate holder plate 28, and the cooling pipe 41 is The cooling pipe 41 is connected to a cooling source (not shown).

[0025] The quartz discharge plate 13 includes a quartz discharge plate holder plate 28 and a quartz discharge plate holding ring. 29, the quartz discharge plate 13 and the quartz discharge plate holder plate 28 An O-ring 42 and a cushion ring 43 made of synthetic resin are interposed between the stones. A cushion ring 44 is interposed between the quartz discharge plate 13 and the quartz discharge plate holding ring 29. will be established.

[0026] The presser ring has a plurality of rings extending in the radial direction at a required pitch along the circumferential direction. A ventilation hole 45 is bored. In addition, a nitrogen gas supply pipe 46 is connected to the top surface of the circular waveguide 7. However, the nitrogen gas supply pipe 46 is connected to a nitrogen gas supply source (not shown).

[0027] The action will be explained below.

[0028] A reaction gas is supplied from a reaction gas supply source (not shown) to the annular groove 35 through the supply pipe 37 and the guide hole 36. supply gas. The reaction gas fills the annular groove 35, and then each communication hole 38 and the stepped portion 3. 9, supplied to the processing chamber 3 via the groove 40.

[0029] The microwave generated by the microwave generation unit 2 is guided to the waveguide unit 4. and introduced into the processing chamber 3. The microwave is reflected by a wafer (not shown) The reactant gas is excited in the vicinity of the quartz discharge plate to generate plasma. This program The wafer is processed by the plasma, and the quartz discharge plate 13 is heated.

[0030] On the other hand, during operation, nitrogen is introduced into the circular waveguide 7 through the nitrogen gas supply pipe 46. Basic gas is supplied, and the nitrogen gas is exhausted to the outside through the ventilation hole 45. During this nitrogen gas distribution process, the nitrogen gas removes heat from the surface of the quartz discharge plate 13. Then, the quartz discharge plate 13 is cooled.

[0031] Further, the ventilation holes 45 are provided near the surface of the quartz discharge plate 13 and along the periphery thereof. Therefore, there is no stagnation in the flow of the nitrogen gas on the surface of the quartz discharge plate 13, and cooling is performed by the quartz discharge plate 13. This is effectively performed over the entire surface of the board 13.

[0032] Furthermore, a coolant such as water is made to flow through the cooling pipe 41, and the quartz discharge plate holder plate 2 8, the O-ring 42 is cooled.

[0033] Since the quartz discharge plate 13 itself is cooled with nitrogen gas, the quartz discharge plate 13 itself is cooled by nitrogen gas, so that the quartz discharge plate 13 itself is cooled by nitrogen gas, so that the quartz The heat transmitted from the discharge plate 46 can be suppressed, and the O-ring 42 itself can also be connected to the cooling pipe 4. 1 is cooled by a refrigerant flowing through it.

[0034] As mentioned above, the wafer processing condition depends on the distance between the plasma and the wafer, that is, the quartz It changes depending on the distance between the discharge plate 13 and the wafer. Therefore, the wafer processing conditions should be adjusted appropriately. In order to obtain the desired state, the position of the quartz discharge plate 13 may be changed.

[0035] In Fig. 1, three ring seats 25, 26, and 27 are stacked on top of each other. Quartz can be removed by removing any two or one of all of the seats 25, 26, and 27. The position of the discharge plate 13 can be changed in various ways. Also, turn the quartz discharge plate 13 upside down. It is also possible to attach the quartz discharge plate 13 and the wafer to a larger distance. can be set.

[0036] Therefore, by appropriately selecting the stacking of the rings 25, 26, and 27, the optimal way can be achieved. It becomes possible to enter the processing state.

[0037] In addition, the rings may have the same thickness, and the number of rings may be prepared as necessary. Bye.

[0038]

[Effect of the idea] As described above, according to the present invention, the distance between the quartz discharge plate and the wafer is changed. It is possible to set the appropriate edge according to the type of reaction gas, gas flow rate, gas pressure, etc. It is possible to obtain high etching speed and also improve etching uniformity. can.

[Brief explanation of drawings]

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

FIG. 2 is an enlarged view of part A in FIG. 1;

FIG. 3 is an overall view of a plasma generator in which the embodiment is implemented.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

3 Wafer processing room 13 Quartz discharge plate 23 Processing chamber container 25 Ring seat 26 Ring seat 27 Ring seat 28 Quartz discharge plate holder plate

Claims (1)

[Scope of utility model registration request] 1. A processing chamber is formed by a processing chamber container and a quartz discharge plate that airtightly closes the upper surface of the processing chamber container, and microwaves are introduced into the processing chamber to generate plasma on the side of the quartz discharge plate processing chamber. In the plasma generating apparatus configured to generate plasma, the quartz discharge plate is attached to the processing chamber container via a quartz discharge plate holder plate, and a ring is provided between the quartz discharge plate holder plate and the processing chamber container. A plasma generator characterized in that a seat can be inserted.