JPH11243079A - Plasma treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment equipment, capable of preventing reaching to an excitation region of dust flying up from a pressure regulating valve which is installed to an exhaust pipe or from the interior wall of the exhaust pipe. SOLUTION: This plasma treatment equipment has a chamber 1, which has an exhaust port 11 and the inside of which is supplied with a reactive gas, a table 2, which is installed into the chamber and in which a semiconductor wafer U is mounted on the top face, a pair of electrodes 3, 5 for exciting the reactive gas and changing it into plasma, an exhaust pump 13 having an exhaust pipe 12 connected to the exhaust port for decompressing the inside of the chamber, a pressure regulating valve 14 for regulating pressure in the chamber decompressed by the exhaust pump 13 mounted on the exhaust pipe 12, and a dust diffusion preventing member 15, which is set up between the excitation region 10 of the reactive gas by the electrodes and the exhaust port, to which the exhaust pipe 12 is connected, in a state which isolates these excitation region 10 and exhaust port, and in which vent holes 17a... are formed at places displaced from the exhaust port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for converting a reactive gas into plasma to plasma-treat an object to be processed.

[0002]

2. Description of the Related Art Microfabrication plays an important role in, for example, a process for manufacturing an VLSI, and an etching technique is used as the microfabrication. That is,
The above-described etching technique is used as a method of transferring a fine photoresist pattern transferred by photolithography to a semiconductor wafer or a glass substrate for liquid crystal as an object to be processed.

[0003] There are two types of etching techniques, dry etching and wet etching. In recent years, dry etching that can realize anisotropic etching by selecting etching conditions has attracted attention.

The structure of a general apparatus used for dry etching has a chamber for holding an object to be processed, a reactive gas for etching is introduced into the chamber, and the reactive gas is supplied to a high frequency or a micro-wave. Excited by a wave to generate plasma, active species such as halogen radicals and ions are generated, and etching is performed by a reaction between the active species and a substrate disposed in the etching chamber.

[0005] An exhaust port is formed in the chamber, and a suction pump is connected to the exhaust port through an exhaust pipe to reduce the pressure in the chamber. The exhaust pipe is provided with a pressure regulating valve, and the pressure in the chamber is regulated by controlling the opening of the pressure regulating valve.

In the plasma processing apparatus having such a configuration, the reactive gas in the chamber is exhausted from the exhaust pipe, and various components contained in the exhaust gas chemically react to form a product. It is inevitable that the product adheres mainly to the pressure regulating valve. In addition to the pressure regulating valve, it adheres to the inner wall of the exhaust pipe.

[0007] When the amount of the product adhering to the pressure regulating valve or the like becomes a predetermined amount or more, the product is separated into dust by a gas flow or the like generated in the exhaust pipe. The dust separated from the pressure control valve or the like is usually discharged from the exhaust pipe by a gas flow generated in the exhaust pipe.

However, if turbulence is generated by the gas flowing through the exhaust pipe colliding with the pressure regulating valve, the dust rises without being exhausted from the exhaust pipe, returns to the plasma region in the chamber, and returns to the workpiece. They may adhere and cause processing defects. It should be noted that the cause of dust soaring can be considered in various other ways.

In order to prevent such processing defects,
The work of disassembling the pressure control valve from the exhaust pipe and cleaning and removing the products adhering to the pressure control valve and the inner wall of the exhaust pipe must be performed frequently, leading to a decrease in productivity and complicating work. There are things.

[0010]

As described above, in the conventional plasma processing apparatus, an impurity component such as a reaction product contained in the exhaust gas contains a pressure regulating valve provided in the exhaust pipe or an inner wall of the exhaust pipe. When the dust adheres to the surface and peels off due to an increase in the amount of the dust, the dust returns to the plasma region in the chamber under the influence of a gas flow flowing through the exhaust pipe.
In some cases, it adheres to the object to be processed and causes defective products.

An object of the present invention is to provide a plasma processing apparatus capable of preventing dust separated from a pressure control valve or the like from returning to a plasma region and adhering to an object to be processed.

[0012]

According to a first aspect of the present invention, there is provided a plasma processing apparatus for plasma-treating an object to be processed by converting a reactive gas into a plasma. A chamber, a table provided in the chamber, on which an object to be processed is placed, an excitation means for exciting the reactive gas to produce plasma, and an exhaust connected to an exhaust port of the chamber An exhaust means for reducing the pressure in the chamber, and an exhaust port provided between the excitation area of the reactive gas by the excitation means and an exhaust port to which the exhaust pipe is connected; And a member having a ventilation hole formed at a different position.

According to a second aspect of the present invention, in the first aspect of the present invention, the member is provided over an entire length between an inner peripheral surface of the chamber and an outer peripheral surface of the table, and the vent hole is formed at least in the air hole. It is characterized in that it is formed at a position substantially 180 degrees shifted from the exhaust port in the circumferential direction.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the member is provided with a plurality of the ventilation holes, the suction force of the exhaust means acting in the chamber in a circumferential direction of the chamber. Are formed in a substantially uniform arrangement.

According to a fourth aspect of the present invention, there is provided a plasma processing apparatus for plasma-treating an object to be processed by converting a reactive gas into plasma, a chamber having an exhaust port and the inside of the chamber being supplied with the reactive gas, A table on which the object to be processed is mounted on the upper surface, excitation means for exciting the reactive gas to produce plasma, and an exhaust pipe connected to an exhaust port of the chamber. Exhaust means for decompressing the inside of the chamber, and a ventilation hole provided between an excitation area of the reactive gas by the excitation means and an exhaust port to which the exhaust pipe is connected and having a smaller inner diameter than the exhaust port And a member formed with

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the member is detachably provided at the exhaust port. According to the invention of claim 1, the reactive gas in the chamber can be exhausted through the vent hole,
The dust generated from the pressure regulating valve collides with the dust diffusion preventing member because the vent hole is displaced from the exhaust port, and is prevented from diffusing into the plasma region through the vent hole.

According to the second aspect of the present invention, the dust diffusion preventing member is provided with a ventilation hole at least at a position shifted by about 180 degrees in the circumferential direction from the exhaust port, so that the exhaust gas discharged from the exhaust port is provided. Since the gas flows over the entire circumference in the circumferential direction of the chamber, the accumulation of dust in the gas flow path formed by the dust diffusion preventing member is prevented.

According to the third aspect of the present invention, the suction force of the exhaust means acting in the chamber is made substantially uniform in the circumferential direction of the chamber, so that the gas flow in the excitation region can be made substantially uniform. .

According to the fourth aspect of the present invention, since the inner diameter of the ventilation hole formed in the dust diffusion preventing member is made smaller than the inner diameter of the exhaust port, dust generated from the pressure regulating valve can pass through the ventilation hole. And the amount returning to the excitation region after passing through can be reduced. According to the fifth aspect of the present invention, the dust diffusion preventing member can be removed from the exhaust port to facilitate cleaning.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the present invention. In the drawings, reference numeral 1 denotes a chamber of a plasma processing apparatus for etching a semiconductor wafer W as an object to be processed, for example. The chamber 1 has a circular cross section, and a table 2 having a circular cross section whose outer dimensions are smaller than the inner diameter of the chamber 1 is disposed inside. The semiconductor wafer W is mounted on the upper surface of the table 2.

On the upper part of the table 2, a disk-like lower electrode 3 slightly smaller in diameter than the sectional shape of the table 2 is provided.
Is buried. This lower electrode 3 is connected to a high frequency power supply 4 as an excitation means.

An upper electrode 5 is disposed in the chamber 1 so as to face the upper surface of the table 2 at a predetermined interval. The upper electrode 5 has a disk 6 having a hollow circular shape (preferably larger in diameter than the table 2), one end connected to the upper surface of the disk 6, and the other end connected to the chamber. 1 and a supply pipe 7 projecting airtight from the upper wall to the outside.

A plurality of outflow holes 8 are formed in the lower surface of the disk portion 6 of the upper electrode 5. The other end of the supply pipe 7 communicates with a supply source of a reactive gas for etching (not shown). Therefore, the reactive gas supplied from the supply source is ejected from the outlet 8 toward the semiconductor wafer W.

When a high-frequency voltage is applied to the lower electrode 3 by a high-frequency power supply 4, a discharge is ignited between the lower electrode 3 and the upper electrode 5. As a result, the reactive gas supplied to the space 10 between these electrodes 3 and 5 (this space is referred to as an excitation region 10) is excited and turned into plasma to form an active species. The semiconductor wafer W mounted on the lower electrode 3 is etched.

Prior to supplying the reactive gas to the chamber 1, the pressure in the chamber 1 is reduced to a predetermined degree of vacuum.
That is, an exhaust port 11 is formed at the bottom of the chamber 1 at a portion between the outer peripheral surface of the table 2 and the inner peripheral surface of the chamber 1. One end of an exhaust pipe 12 is connected to the exhaust port 11. The other end of the exhaust pipe 12 is the exhaust pump 1
3 is connected. Therefore, the exhaust pump 13
Is operated, the inside of the chamber 1 is depressurized.

A pressure regulating valve 14 is provided inside one end of the exhaust pipe 12. The opening of the pressure adjusting valve 14 is adjusted by a driving unit (not shown) according to the supply amount of the reactive gas supplied from the supply pipe 7. Thereby, the inside of the chamber 1 is controlled to a predetermined pressure.

In the present embodiment, a ring-shaped dust diffusion barrier for separating the excitation region 10 from the exhaust port 11 is provided between the excitation region 10 and the exhaust port 11, in this embodiment, on the outer peripheral surface of the table 2. A member 15 is provided at a predetermined interval from the inner bottom surface of the chamber 1. As a result, the above-described tape is placed between the lower surface of the dust diffusion preventing member 15 and the inner bottom surface of the chamber 1.
An annular flow path 16 along the entire outer peripheral surface of the cable 2 is formed separately from the excitation region 10.

The dust diffusion preventing member 15 has a plurality of, and in this embodiment, five rectangular ventilation holes 17 communicating with the excitation region 10 and the flow path 16 as shown in FIG.
a to 17e are exhaust ports 10 formed at the bottom of the chamber 1.
And the position is shifted.

That is, one of the five ventilation holes 17a
Is provided at a position shifted from the exhaust port 10 by about 180 degrees in the circumferential direction of the chamber 1, and two of the remaining four vent holes 17 b and 17 c are clockwise and counterclockwise from the exhaust port 10. And the other two ventilation holes 17d and 17e are respectively about 3 clockwise and counterclockwise from the exhaust port 10 respectively.
It is provided at a position shifted by 6 degrees.

Next, the operation of the plasma processing apparatus having the above configuration will be described. When the unprocessed semiconductor wafer W is placed on the upper surface of the table 3, the exhaust pump 13 is operated to reduce the pressure in the chamber 1 to a predetermined pressure. Then
A reactive gas for etching is supplied from a supply tube 7 of the upper electrode 5, and the reactive gas is supplied to the excitation region 10 from an outlet 8 of the disk 6.

At the same time as the supply of the reactive gas, the high-frequency power supply 4 is operated to ignite a discharge between the lower electrode 3 and the upper electrode 5. The discharge excites the reactive gas supplied to the discharge region 10, so that the reactive gas is turned into plasma and the semiconductor wafer W on the table 3 is etched.

In etching the semiconductor wafer W,
By controlling the opening of the pressure regulating valve 14, the chamber 1
Since the suction force of the exhaust pump 13 acting inside is also controlled,
The pressure in the chamber 1 is kept constant. That is, while the reactive gas is supplied from the upper electrode 5 to the excitation region 10, the amount of the reactive gas from the excitation region 10 discharged through the exhaust pipe 12 by the exhaust pump 13 is controlled by the pressure regulating valve 1.
The pressure in the chamber 1 is controlled by adjusting the pressure in the chamber 4.

By continuing such an operation, various components contained in the reactive gas undergo a chemical reaction, and a product of the chemical reaction adheres and accumulates on the inner surface of the pressure regulating valve 14 and the exhaust pipe 12. When the amount of the adhered product increases, the product is separated from the pressure control valve 14 and the like to become dust d. Usually, the dust d is discharged together with the reactive gas discharged from the exhaust pipe 12, and the flow of the reactive gas is controlled by the pressure regulating valve 14.
When the turbulence is caused by the opening / closing of the nozzle and the like, it may soar upward from the exhaust port 11 as shown in FIG.

The dust d rising upward from the exhaust port 11 is provided with ventilation holes 17a to 17e formed in the dust diffusion preventing member 15, which is a member provided in a state where the excitation region 10 and the exhaust port 11 are separated from each other. Through the excitation region 10
And may adhere to the semiconductor wafer W. However, the ventilation holes 17a to 17e are formed at positions shifted from the exhaust port 11 in the circumferential direction of the table 2.

As a result, the dust d rising upward from the exhaust port 11 does not immediately pass through the ventilation holes 17a to 17e and collides with the lower surface of the dust diffusion preventing member 15, so that the dust d adheres to the lower surface or exhausts. Since it is discharged from the tube 12, it hardly flows out to the excitation region 11 and adheres to the semiconductor wafer W.

One of the five ventilation holes 17a to 17e formed in the dust diffusion preventing member 15 is 17a.
Is formed at a position shifted from the exhaust port 11 by about 180 degrees in the circumferential direction. For this reason, the flow path 16
Since the reactive gas sucked into the exhaust port 11 is separated into the left and right from the vent hole 17a and is discharged from the exhaust port 11 to the exhaust pipe 12,
For example, even if the dust d enters the flow path 16, the dust d flows together with the reactive gas to the exhaust port 11 and is discharged from the exhaust pipe 12.

That is, one of the ventilation holes 17a to 17e formed in the dust diffusion preventing member 15 is
It is formed at a position shifted 180 degrees in the circumferential direction from the exhaust port 11. The reactive gas sucked into the flow path 16 from the exhaust port 17a flows in the left-right direction as shown by the arrow in FIG. 2 and merges with the reactive gas sucked from the other ventilation holes 17b to 17e to form the exhaust port 11 To

Therefore, about 180 circumferentially from the exhaust port 11
Since the vent hole 17a is formed at a position shifted by a degree, the reactive gas flows through the entire length of the flow path 16. Therefore, it is possible to prevent the dust d from accumulating in the flow path 16 and flowing out from the ventilation holes 17a to 17e to the excitation region 10 when the pressure in the chamber 1 fluctuates or when turbulence occurs.

Exhaust pump 13 acting on five air holes 17a to 17e formed in dust diffusion preventing member 15
Is larger at the ventilation holes 17d and 17e near the exhaust port 11 than at the ventilation holes 17a to 17c far from the ventilation holes 17d.

However, two vent holes 17d and 17e are formed on the side close to the exhaust port 11, that is, in a range of 90 degrees left and right around the exhaust port 11, and in the other range, three vent holes 17a to 17c are formed. Is formed, the reactive gas is almost uniformly sucked and discharged from the entire circumferential direction of the table 3, that is, from the excitation region 10.

As a result, the plasma density in the excitation region 10 becomes substantially uniform, so that the etching of the semiconductor wafer W can be performed substantially uniformly over the entire plate surface. If the allowable range of the uniformity of the plasma density is wide depending on the process conditions, only one of the vent holes 17a to 17e may be provided from the viewpoint of preventing dust d.

FIG. 3 shows a second embodiment of the present invention. In the following embodiments, the same parts as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, in order to prevent dust d from accumulating in the flow path 16,
For example, a pair of ventilation holes 21a, 21b
In this way, each vent hole 2
The reactive gas sucked from 1a and 21b surely separates right and left as shown by arrows in the figure, and flows through the flow path 16 with the flow rates of the left and right being substantially equalized. It is difficult to remain.

Although the vent holes 21a and 21b are not square holes but round holes, they may be square holes. In addition, approximately 18
The same effect can be obtained even if a plurality of ventilation holes are formed, not limited to two at the position of 0 degrees.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, similarly to the first embodiment, the dust diffusion preventing member 15 has five vent holes 22a to 22 made of round holes.
e are formed, but these vents 22a to 22e are set to different sizes.

That is, approximately 18 cm from the exhaust port 11 in the circumferential direction.
The vent hole 22a located at a position separated by 0 degrees is set to be the largest, and then a pair of vent holes 22b and 22c located approximately 108 degrees left and right from the exhaust port 11, and then a pair of vent holes 22d located 36 degrees. , 22e in order.

By changing the size of each of the ventilation holes 22a to 22e in this way, the suction force acting on each of the ventilation holes 22a to 22e is inversely proportional to the size of the ventilation hole. The amount of the reactive gas sucked into the passage 16 can be substantially equalized.

As a result, the distribution of the reactive gas in the excitation region 10 can be made substantially uniform, so that the etching of the semiconductor wafer W can be performed almost uniformly. FIG. 5 shows a fourth embodiment of the present invention. This embodiment is similar to the first embodiment in that the dust diffusion preventing member 15 is formed with five ventilation holes 23a to 23e of the same size. The arrangement angles are different. That is, the vent holes 23a are the same in that they are located at substantially 180 degrees in the circumferential direction from the exhaust port 11, but the vent holes 23b and 23c are
Formed at a position of 140 degrees left and right from the air hole 23d,
23e is different in that it is formed at a position 60 degrees to the left and right from the exhaust port 11 and that it is a round hole.

As described above, the two ventilation holes 23b and 23c
By locating the gasses farther from the exhaust port 11 than in the first embodiment, it is possible to increase the arrangement density of the ventilation holes at a portion far from the exhaust port 11. Can be more evenly flowed over.

FIG. 6 shows a fifth embodiment of the present invention. In this embodiment, the number of round vent holes formed in the dust diffusion preventing member 15 is nine. That is, the exhaust port 1
A vent hole 24a is formed at a position shifted by 180 degrees in the circumferential direction from 1, and two vent holes 24b to 24e are formed on both sides of the vent hole 24a. Further, ventilation holes 24f and 24g were formed at 90 degrees left and right from the exhaust port 11, respectively, and ventilation holes 24h and 24i were formed at 45 degrees.

As described above, by increasing the density of the ventilation holes 24 a to 24 e formed in the portion far from the exhaust port 11, the flow of the reactive gas sucked from the excitation region 10 to the flow path 16, that is, the excitation region The distribution density of the reactive gas in 10 can be made even more uniform than in the other embodiments.

FIGS. 7 and 8 show a sixth embodiment of the present invention. In this embodiment, the chamber 1 has 18
Two exhaust ports 11 are formed at 0-degree intervals, and two dust holes 25 formed of round holes are formed in the dust diffusion preventing member 15 at positions 90 degrees in the circumferential direction from each exhaust port 11.

An exhaust pipe 12 is connected to each exhaust port 11.
Each of these exhaust pipes 12 is provided with a pressure regulating valve 14 as in the first embodiment. As described above, since the positions of the vent holes 25 and the exhaust ports 11 are shifted by 90 degrees in the circumferential direction, the duct d generated from the pressure regulating valve 14 and the inner wall of the exhaust pipe 12 is excited through the vent holes 25. Not only can it be prevented from flowing into the region 10, but also by connecting the exhaust pipes 12 each having the pressure regulating valve 14 to the two exhaust ports 11, the suction force generated in the two ventilation holes 25 can be substantially reduced. Since the reactive gas can be made uniform and the reactive gas sucked from the excitation region 10 can flow over the entire circumference of the flow path 16, accumulation of dust d in the flow path 16 can be prevented.

FIG. 9 shows a seventh embodiment of the present invention.
Four exhaust ports 11 are formed at 0-degree intervals, and each exhaust port 11 has an exhaust pipe 1 (not shown) with a built-in pressure regulating valve 14.
2 are respectively connected.

Four dust holes 26 formed of round holes are formed in the dust diffusion preventing member 15 at intervals of 90 degrees in the circumferential direction, and at positions shifted 45 degrees in the circumferential direction with respect to the exhaust ports 11.

As described above, by increasing the number of exhaust ports 11, the suction of the reactive gas from the excitation region 10 in the circumferential direction of the table 2 is made more uniform as compared with the sixth embodiment. be able to.

Although the cross-sectional shape of the chamber 1 is circular in the first to seventh embodiments, it may be rectangular instead of circular. In addition, since the case where the semiconductor wafer W is processed as the processing object has been described, the planar shape of the table 2 is circular. However, when the processing object is a glass substrate for liquid crystal, the planar shape of the table 2 is changed. It is better to make the shape rectangular in accordance with the shape of the glass substrate for liquid crystal. In this case, if the cross-sectional shape of the chamber 1 is made rectangular so as to correspond to the glass substrate for liquid crystal, it is possible to prevent the generation of useless space around the table 2.

FIGS. 10 and 11 show an eighth embodiment of the present invention. In this embodiment, the dust diffusion preventing member 15 is used.
In this modification, the dust diffusion preventing member 31 can be detachably fitted into the flow path 16 around the table 2 having a circular planar shape.

That is, the dust diffusion preventing member 31 is divided into, for example, four arc members 32 so as to be easily attached and detached. Each arc member 32 is formed in an inverted U-shaped cross section, and the upper surface thereof has the exhaust port 11 extending over the entire length in the circumferential direction.
Are formed in, for example, a zigzag pattern. For example, assuming that the diameter of the exhaust port 11 is R, the diameter r of the vent 27 is 2 to 5 mm.
It is set to about one-half the size.

According to such a configuration, since the vent hole 27 is smaller than the exhaust port 11, at least a part of the exhaust port 11 does not need to be displaced from the exhaust port 11, and at least a part of the exhaust port 11 is a dust blocking member. 31 are covered by portions where the ventilation holes 27 are not formed.

Therefore, even if the dust d accumulated on the inner wall of the pressure regulating valve 14 or the exhaust pipe 12 flies for some reason, the dust d is generated at a probability corresponding to the degree to which the dust blocking member 31 covers the exhaust port 11. Blocking member 31
Collide with

Therefore, the size of the ventilation hole 27 formed in the dust blocking member 31 is made smaller than the size of the exhaust port 11 to prevent or reduce the dust d from flowing out to the excitation region 10. Can be.

By appropriately setting the size and pitch of the ventilation holes 27, the probability that the dust d will flow out of the ventilation holes 27 into the excitation region 10 can of course be set sufficiently low. .

FIG. 12 shows a ninth embodiment of the present invention. In this embodiment, a recess 35 communicating with the exhaust port 11 is formed along the circumferential direction of the chamber 1 around the table 2 at the bottom of the chamber 1.

The recess 35 and the exhaust port 11 are
It is closed by a dust diffusion preventing member 36, which is a member provided so as to separate the exhaust port 11 from the exhaust port 11. The dust diffusion preventing member 36 has a vent hole 2 at a position shifted from the exhaust port 11 and at a position facing the concave portion 35.
8 are formed.

According to such a configuration, the reactive gas supplied to the excitation region 10 is discharged from the ventilation hole 28 formed in the dust diffusion preventing member 36 to the exhaust pipe 12 through the exhaust port 11.

Conversely, when dust d accumulated on the pressure regulating valve 14 provided on the exhaust pipe 12 or on the inner wall of the exhaust pipe 12 flies for some reason such as turbulence, the dust d collides with the dust diffusion preventing member 36. Therefore, the gas is prevented from flowing out to the excitation region 10 through the ventilation hole 28.

The recess 35 is formed by the dust diffusion preventing member 36.
By covering the discharge port 11 and the discharge port 11, it is not necessary to form the flow path 16 around the table 2 as in each of the above-described embodiments. You don't have to do that. Moreover, the dust diffusion preventing member 36 needs to be provided only in a part of the table 2 in the circumferential direction, which is advantageous in terms of cost.

FIG. 13 shows a tenth embodiment of the present invention. This embodiment is a modification of the eighth embodiment shown in FIGS. 10 and 11, in which a taper portion 41 whose diameter is increased radially outward is formed at the upper end of the exhaust port 11. Have been. The taper section 41 has an excitation area 10 and an exhaust port 11.
A disc-shaped dust diffusion preventing member 42, which is a member provided in a state where the dust diffusion preventing member is separated, is detachably fitted.
In the dust diffusion preventing member 42, a plurality of vent holes 29 having a smaller diameter than the exhaust port 11, for example, about one-half to one-fifth, are provided in a peripheral portion corresponding to the taper portion 41.
Are formed at predetermined intervals in the circumferential direction.

According to such a configuration, the inner diameter of the ventilation hole 29 formed in the dust diffusion preventing member 42 is
Not only is it smaller than the inside diameter of 1,
The vent hole 29 is formed at a position corresponding to a taper portion 41 formed radially outward of the exhaust port 11.

Therefore, even if dust rises from the inner wall of the pressure regulating valve 14 or the exhaust pipe 12 due to the influence of turbulence or the like, most of the dust collides with a portion of the dust diffusion preventing member 42 where the vent hole 29 is not formed. Therefore, it hardly flows out of the excitation region 10 through the ventilation hole 29. In addition, the probability that the dust d passes through the ventilation holes 29 can be reduced depending on the size and the number of the ventilation holes 29.

Further, the dust diffusion preventing member 42 is connected to the exhaust port 1.
By being detachably provided on the device 1, it is not necessary to form the flow path 16 around the table 2, so that the dust d flying from the pressure regulating valve 14 and the like does not accumulate in the flow path 16. Further, the dust diffusion preventing member 42 can be removed from the exhaust port 11 to easily clean the dust d adhered to the exhaust port 11.

The present invention is not limited to the above embodiments, and it goes without saying that the present invention can be applied to not only etching but also CVD or ashing as plasma processing. Also, in the example in which the exhaust port 11 is provided on the side surface of the chamber 1 as shown in FIG. The same effect as in the embodiment can be obtained. Further, the means for exciting the reactive gas is not limited to a pair of upper and lower electrodes. For example, microwaves may be introduced into the chamber by a waveguide.

[0073]

As described above, according to the present invention, the exhaust port is shifted between the excitation region to which the reactive gas is supplied and the exhaust port connected to the exhaust pipe formed in the chamber. A dust diffusion preventing member having a vent hole smaller than the position or the exhaust port is provided.

Therefore, even if dust adhering to the pressure regulating valve provided on the exhaust pipe rises without impairing the exhaust state of the reactive gas from the exhaust port, the dust passes through the vent hole. It can be prevented from flowing out to the excitation region and adhering to the object to be processed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the inside of a chamber showing a first embodiment of the present invention.

FIG. 2 is a plan view of the inside of the chamber.

FIG. 3 is a plan view showing the inside of a chamber according to a second embodiment of the present invention.

FIG. 4 is a plan view showing the inside of a chamber according to a third embodiment of the present invention.

FIG. 5 is a plan view showing the inside of a chamber according to a fourth embodiment of the present invention.

FIG. 6 is a plan view showing the inside of a chamber according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of the inside of a chamber showing a sixth embodiment of the present invention.

FIG. 8 is a plan view of the inside of the chamber.

FIG. 9 is a plan view showing the inside of a chamber according to a seventh embodiment of the present invention.

FIG. 10 is a sectional view of the inside of a chamber showing an eighth embodiment of the present invention.

FIG. 11 is a plan view of the inside of the chamber.

FIG. 12 is a sectional view of a chamber bottom showing a ninth embodiment of the present invention.

FIG. 13 is a sectional view of a chamber bottom showing a tenth embodiment of the present invention.

FIG. 14 is a sectional view of the inside of a chamber showing a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Chamber 2 ... Table 3 ... Lower electrode 4 ... High frequency power supply 5 ... Upper electrode 7 ... Supply pipe 8 ... Outflow hole 10 ... Excitation area 11 ... Exhaust port 12 ... Exhaust pipe 13 ... Exhaust pump 14 ... Pressure regulation valve 15 ... Dust diffusion preventing member 16 ... Flow paths 17a to 17f ... Vent holes

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaki Handa 6-6 Kita Industrial Park, Kitakami City, Iwate Prefecture Inside Iwate Toshiba Electronics Corporation (72) Inventor Masaru Ueashiki 6-6 Kita Industrial Park, Kitakami City, Iwate Prefecture No. Iwate Toshiba Electronics Co., Ltd.

Claims (5)

[Claims] 1. A plasma processing apparatus for plasma-treating an object to be processed by converting a reactive gas into plasma, comprising: a chamber having an exhaust port and the above-mentioned reactive gas being supplied therein; A table on which the object to be processed is placed; an exciting means for exciting the reactive gas to produce plasma; and an exhaust pipe connected to an exhaust port of the chamber, and the inside of the chamber is depressurized. An exhaust means, a member provided between the excitation area of the reactive gas by the excitation means and an exhaust port to which the exhaust pipe is connected, and having a vent formed at a position shifted from the exhaust port; A plasma processing apparatus comprising: 2. The member is provided over an entire length between an inner peripheral surface of the chamber and an outer peripheral surface of the table,
The vent hole is at least approximately 1 in the circumferential direction from the exhaust port.
2. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is formed at a position shifted by 80 degrees. 3. The member is characterized in that the plurality of ventilation holes are formed in such an arrangement that the suction force by the exhaust means acting in the chamber becomes substantially uniform in the circumferential direction of the chamber. Claim 1 or Claim 2
The plasma processing apparatus as described in the above. 4. A plasma processing apparatus for plasma-treating an object to be processed by converting a reactive gas into a plasma, comprising: a chamber having an exhaust port and the reactive gas being supplied therein; A table on which the object to be processed is placed; an exciting means for exciting the reactive gas to produce plasma; and an exhaust pipe connected to an exhaust port of the chamber, and the inside of the chamber is depressurized. A member that is provided between an exhaust unit and an exhaust port to which the exhaust pipe is connected, and that is provided between a region where the reactive gas is excited by the excitation unit and an exhaust port to which the exhaust pipe is connected; A plasma processing apparatus comprising: 5. The plasma processing apparatus according to claim 4, wherein said member is detachably provided at said exhaust port.