JPH10270429A - Plasma treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treating device which can form homogeneous plasma over a large area and can evenly treat a large-diameter sample. SOLUTION: A plurality of ring-like permanent magnets 11 having the same polarity in the peripheral direction are arranged on concentric circles on the atmosphere side of a second electrode 25 oppositely faced to a stage 26 on which an object 2 to be treated is placed so that the polarities of the magnets 11 which become adjacent to each other in the diametral direction may become opposite to each other. In addition, a chlorine gas and a sulfur hexafluoride gas are supplied to a plasma generating chamber 22.

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, and more particularly, to a plasma processing apparatus for forming a thin film on a surface of an object using plasma or etching the surface of the object. About.

[0002]

2. Description of the Related Art FIG. 5 is a schematic sectional view showing a conventional plasma processing apparatus described in, for example, JP-A-2-9452. In the figure, a vacuum vessel 101, a first electrode 103 on which an object to be etched 102 is mounted,
And a second electrode 104 disposed opposite to the first electrode 103.

An etching gas is introduced into the vacuum chamber 1 from a gas inlet 105 and exhausted from an exhaust port 106. A high frequency power supply 107 is connected to the first electrode 103 via a matching circuit 108. Further, a permanent magnet 109 is arranged on the atmosphere side of the second electrode 104. Further, in FIG. 5, a cooling mechanism 110 is connected to the first electrode 103. In FIG. 5, E represents an electric field, and B is a component of a magnetic field induced by the magnet 109, which is parallel to the first electrode 103.

Next, the operation of the plasma processing apparatus having the above configuration will be described. When an etching gas is introduced from the gas inlet 105 into the plasma chamber of the vacuum vessel 101, the high-frequency power applied to the first electrode 103 causes
Plasma is generated between the first electrode 103 and the second electrode 104.

The device shown in FIG. 5 aims at obtaining a high electron density even at a low pressure by magnetron discharge, and is set so that the magnetic flux density on the surface of the first electrode 103 becomes about 200 G.

At this time, in the sheath region (where the plasma is in contact with the first electrode 103), charged particles (electrons and ions) drift in the direction of E × B while performing cycloidal movement under the influence of the sheath electric field and magnetic field. To go.

As a result, electrons and neutral particles (atoms and molecules)
The probability of collision with the gas increases, and ionization is promoted, so that high-density plasma is generated even at a low pressure, and a high etching rate can be obtained. In this case, since the loss of plasma is reduced by the magnetic field generated by the permanent magnet 109, high-density plasma is maintained and the object to be processed 102 is etched.

On the other hand, in order to process a large-diameter workpiece having a size of 8 inches or 10 inches in recent years, it is necessary to generate a uniform plasma over a large area. However, in the above-described plasma processing apparatus, since the permanent magnet alone is arranged, the magnetic flux density in the horizontal (parallel between the electrodes) direction on the surface of the second electrode 104 is small at the center as shown in FIG. Therefore, it becomes difficult to form a magnetic field having a uniform intensity near the object to be processed.

For this reason, although there is a homogenizing effect by plasma diffusion, it is difficult to generate uniform plasma. FIG. 6 shows a diameter of 200 mm and a height of 50 mm.
In the case where permanent magnets having a surface magnetic flux density of 3 kG and all being uniform are provided, a second electrode 10 35 mm away from the magnet is provided.
It is a graph which shows the horizontal magnetic field distribution on four surfaces. The vertical axis represents the magnetic field strength in the horizontal direction: B⊥ (G), and the horizontal axis represents the distance from the center: r (mm).

Further, the magnetic field distribution on the surface of the object placed on the first electrode 103 becomes non-uniform. Since the motion of the charged particles is greatly affected by the magnetic field distribution, the flux of the charged particles incident on the surface of the object to be processed becomes non-uniform, reflecting the non-uniform magnetic field distribution. As a result, there is a problem that a charge density distribution on the surface of the object to be processed appears and the processed device is damaged.

In the case where adjacent magnets are arranged so that the polarities of the adjacent magnets are the same even when a plurality of permanent magnets are used, the magnetic field distribution becomes non-uniform as in the case where a single magnet as described above is arranged. Therefore, the uniformity of the plasma was insufficient even if the uniforming action by the diffusion of the plasma was taken into consideration.

Further, JP-A-2-9452 discloses that
As shown in the schematic cross-sectional configuration diagram of FIG. 7, it is disclosed that a plurality of bar-shaped permanent magnets are arranged with the polarities of adjacent magnets reversed. When the magnetism is alternately changed, the radial distribution of the transverse magnetic flux density B⊥ on the surface of the second electrode 104 has a waveform as shown in FIG.

As can be seen from FIG. 8, B⊥ is not uniform in the radial direction, but the position of the peak can be controlled by changing the magnet interval and the like. When plasma is generated in this magnetic field configuration, the plasma spreads even to the weak magnetic field, so that the plasma can be homogenized, and the loss can be reduced compared to the case without a magnet. .

[0014] However, for example, when a plurality parallel arrangement a rod-shaped permanent magnet as shown in FIG. 7, B _1, B
_Two magnetic fields are formed. Therefore, in the region (A) near the object to be processed, the electric field E and the magnetic field B ₁ cause the E × B drift to penetrate the paper, and in the region (B), the electric field E
And the magnetic field B ₂ causes the plasma to drift in the opposite direction and to be unevenly distributed.

Considering the movement of charged particles in the sheath portion on the surface of the second electrode 104, as shown in the explanatory view of FIG. 9, the drift direction between adjacent magnets due to the E × B drift (see FIG. 9). (Indicated by an arrow), and a portion having a high plasma density is formed in the drift direction, so that the portion represented by the inclined portion has a high density. As described above, in the case of the parallel arrangement, the plasma density tends to be non-uniform, and therefore, the uniformity of the etching rate is also deteriorated. This is a fundamental problem of the parallel arrangement.

On the other hand, FIG.
1 is a schematic configuration diagram illustrating a conventional plasma processing apparatus in which a plasma generation chamber and a processing chamber disclosed in Japanese Patent No. 8182 are separately provided. In the figure, a processing chamber 121 includes a main valve 131.
The diffusion pump 132 and the auxiliary rotary pump 133 are interposed
Is evacuated. Above the processing chamber 121, a plasma generation chamber 122 is provided. Plasma generation chamber 12
2, the counter electrodes 118 and 119 are grounded, and the counter electrode 11 having a plurality of holes 20 is provided between the counter electrode 11 and the processing chamber 121.
9 is used as a partition. The source gas cylinder 134 is connected to the gas introduction pipe 115.

Next, the operation of the plasma processing apparatus having the above structure will be described. When an etching gas is introduced into the plasma generation chamber 122 from the gas introduction pipe 115, the gas is exhausted from the plasma generation chamber 122 through the processing chamber 122 by a vacuum pump. At this time, the plasma generation chamber 122
Due to the conductance of the hole 20 provided between the plasma generation chamber 122 and the processing chamber 121, a pressure difference occurs between the plasma generation chamber 122 and the processing chamber 121.

According to the specific numerical values shown in the conventional example, the diameter of the holes is 0.1 to 0.8 mm, the number of holes is 7, the effective exhaust speed of the exhaust system is 1000 L / sec, and the flow rate of the raw material gas is 50 to
Under the conditions of 100 cc / min, the pressure of the plasma generation chamber 122 is 1 to 5 × 10 ⁻¹ Torr, and the pressure of the processing chamber is 1 × 1.
0 ^-3 Torr or less.

Next, when high-frequency power is supplied from the high-frequency power supply 117 to the counter electrodes 118 and 119, plasma is generated in the plasma generation chamber 122. The plasma passes through the hole 120 and etches the workpiece 102 placed on the table 126 installed in the processing chamber 121.

In the plasma processing apparatus configured as described above,
In this case, the plasma generation chamber 1
The plasma density generated at 22 is at most 5 × 10⁸(Pieces/
cm ^Three) To 5 × 10⁹(Pcs / cm^Three)Met. one
On the other hand, the processing speed of the processing target 102 is incident on the processing target 102.
To some extent the plasma density. Therefore, generate
If the plasma density is limited, high-density plasma
The processing target cannot be processed at high speed because it cannot be guided to the processing chamber 121.
Was impossible to manage. In addition, parallel plate type high circumference
The pressure of the plasma generation chamber 122 at which the wave discharge is maintained is:
Since it is about 0.1 Torr, in a higher vacuum atmosphere
There is a problem that the object cannot be processed.

[0021]

The conventional plasma processing apparatus is configured as described above. For example, when a single magnet is provided as shown in FIG. 5, the magnetic flux density is one outward from the center. And the uniform magnetic field distribution cannot be formed, so that the plasma density becomes non-uniform.

When a plurality of magnets are arranged in parallel with alternating polarities as shown in FIG. 7, the drift direction differs between adjacent magnets, and a portion having a high plasma density is formed in the drift direction. As a result, the plasma density becomes non-uniform. For this reason, there is a problem that a large-area workpiece cannot be uniformly etched.

Further, in a plasma processing apparatus configured as shown in FIG. 10 in which a plasma generation chamber and a processing chamber are separated, the plasma density generated in the plasma generation chamber is low, and high-density plasma is supplied to the processing chamber. I ca n’t lead,
Cannot process at high speed. In addition, there is a problem that when the plasma density is to be increased, the object cannot be processed in a high vacuum atmosphere.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and provides a plasma processing apparatus capable of forming a uniform plasma over a large area and uniformly processing a large-diameter workpiece. With the goal. Still another object is to provide a plasma processing apparatus capable of increasing the density of plasma generated in a plasma generation chamber and performing high-speed processing in a high vacuum atmosphere. further,
A third object is to provide a plasma processing apparatus capable of generating uniform and high-density plasma over a large area and performing uniform high-speed processing of a large-diameter workpiece in a high vacuum atmosphere.

[0025]

According to one aspect of the plasma processing apparatus according to the present invention, a processing chamber in which a first electrode on which an object to be processed is placed is placed in a vacuum vessel; A plasma generation chamber having a second electrode disposed opposite to the first electrode in the container, provided between the processing chamber and the plasma generation chamber, and communicating from the plasma generation chamber to the processing chamber; A plasma processing apparatus comprising: a partition plate having holes to be processed; and supplying chlorine gas and sulfur hexafluoride gas to the plasma generation chamber to perform the surface treatment of the workpiece.

As described above, when the chlorine gas and the sulfur hexafluoride gas are supplied to the plasma generation chamber in the plasma processing apparatus in which the inside of the vacuum chamber is divided into the plasma generation chamber and the processing chamber by the partition plate, the plasma generation is performed. Due to the pressure difference generated between the chamber and the processing chamber, highly directional plasma toward the object to be processed is generated. Thus, it is possible to give the highly isotropic sulfur hexafluoride gas directionality toward the object to be processed. As a result, even when a highly reactive sulfur hexafluoride gas is used, anisotropic etching in the depth direction of the object can be realized.

Preferably, the chlorine gas is supplied constantly, and the sulfur hexafluoride gas is supplied in a pulsed manner. Thus, by supplying the sulfur hexafluoride gas in a pulsed manner, when the sulfur hexafluoride gas is supplied, the pressure in the plasma generation chamber temporarily increases, and the pressure between the plasma generation chamber and the processing chamber is increased. The difference can be further increased.
As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

Next, in another aspect of the plasma processing apparatus according to the present invention, in a vacuum chamber, a processing chamber in which a first electrode on which an object to be processed is placed is disposed; A plasma generation chamber having a second electrode opposed to the first electrode; and a hole provided between the processing chamber and the plasma generation chamber, and communicating with the processing chamber from the plasma generation chamber. A plasma processing apparatus comprising: a chlorine plate supplied to the plasma generation chamber; and a sulfur hexafluoride gas supplied to the processing chamber, thereby performing a surface treatment of the object to be processed. .

As described above, by supplying chlorine gas to the plasma generation chamber and supplying sulfur hexafluoride gas to the processing chamber, the sulfur hexafluoride gas is a negative gas. When the sulfur gas is supplied, the plasma discharge becomes unstable. However, since the chlorine gas is supplied to the plasma generation chamber, the plasma discharge can be performed in a stable state, and the surface of the object to be processed is stabilized. Processing can be performed.

Preferably, the supply of the chlorine gas and the supply of the sulfur hexafluoride gas are performed in a pulsed manner. As described above, by supplying the chlorine gas and the sulfur hexafluoride gas in a pulsed manner, when the chlorine gas and the sulfur hexafluoride gas are supplied, the pressure of the plasma generation chamber is temporarily reduced. And the pressure difference between the plasma generation chamber and the processing chamber can be further increased. As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

Next, in still another aspect of the plasma processing apparatus according to the present invention, there is provided a processing chamber in which a first electrode on which an object to be processed is placed is placed in a vacuum vessel;
A plasma generation chamber having a second electrode disposed opposite to the first electrode in the vacuum vessel, and a plasma generation chamber provided between the processing chamber and the plasma generation chamber; And a partition plate having holes communicating with the plasma processing chamber, wherein a sulfur hexafluoride gas is supplied to the plasma generation chamber, and a chlorine gas is supplied to the processing chamber, whereby the surface treatment of the object to be processed is performed. Are doing.

As described above, by supplying sulfur hexafluoride gas to the plasma generation chamber and supplying chlorine gas to the processing chamber, conventionally, when sulfur hexafluoride gas is turned into plasma, a polymer of S is generated. Therefore, the polymer adheres to the inner wall of the processing chamber, and the adhered polymer adheres as dust during or after the etching of the object to be processed. Therefore, there is a problem in performing fine processing of the object to be processed. However, such a problem hardly occurs.

When sulfur hexafluoride gas is discharged in the plasma generation chamber, a polymer film is formed. However, since the pressure in the plasma generation chamber is higher than the pressure in the processing chamber, the polymer film diffuses to the wall of the plasma generation chamber. Never. As a result, the polymer film does not adhere to the walls of the processing chamber and does not fall down onto the object as dust, so that extremely clean etching of the object can be realized.

Preferably, the chlorine gas is supplied constantly, and the sulfur hexafluoride gas is supplied in a pulsed manner.
Thus, by supplying the sulfur hexafluoride gas in a pulsed manner, when the sulfur hexafluoride gas is supplied, the pressure in the plasma generation chamber temporarily increases, and the pressure between the plasma generation chamber and the processing chamber is increased. The difference can be further increased. As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

In still another aspect of the plasma processing apparatus according to the present invention, the plasma processing apparatus includes a processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum vessel; A plasma generation chamber having a second electrode opposed to the first electrode, and a partition provided between the processing chamber and the plasma generation chamber and having a hole communicating from the plasma generation chamber to the processing chamber. A plasma processing apparatus comprising: a plate; and supplying chlorine gas and oxygen gas to the plasma generation chamber to perform the surface treatment of the workpiece.

As described above, when the chlorine gas and the oxygen gas are supplied to the plasma generation chamber, in a structure having the plasma generation chamber and the processing chamber, the plasma generation is performed by the pressure difference between the plasma generation chamber and the processing chamber. Since the plasma generated in the chamber is transported to the processing chamber, the plasma reaches the bottom inside the fine pattern of the object to be processed. As a result, the etching characteristics are the same in the fine pattern and the region other than the fine pattern, whereby the microloading effect, which has conventionally been a problem, can be reduced, and the workpiece can be etched accurately.

In still another aspect of the plasma processing apparatus according to the present invention, in a vacuum chamber, a processing chamber in which a first electrode on which an object to be processed is placed is arranged, and in the vacuum chamber, A plasma generation chamber having a second electrode opposed to the first electrode, and a partition provided between the processing chamber and the plasma generation chamber and having a hole communicating from the plasma generation chamber to the processing chamber. A plasma processing apparatus comprising: a plate; an oxygen gas supplied to the plasma generation chamber; and a chlorine gas supplied to the processing chamber.
In this way, by supplying oxygen gas to the plasma generation chamber, chlorine gas, which is a process gas, does not generate plasma. Therefore, generation of dust, contamination, and the like in the plasma generation chamber are prevented, and accuracy is improved. It becomes possible to perform a high etching process on an object to be processed.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plasma processing apparatus according to the present invention will be described below with reference to the drawings, taking an etching apparatus as an example.

[First Embodiment] FIG. 1 is a sectional view showing a schematic configuration of a plasma dry etching apparatus according to a first embodiment of the present invention. A processing chamber 21 is provided in the vacuum chamber 1. A stage 26 constituting a first electrode on which the object 2 is placed is provided in the processing chamber 21. The stage 26 includes a high-frequency power source 2
8 supplies high frequency power. Further, a plasma generation chamber 22 is provided in the vacuum vessel 1 with a partition plate 24 interposed between the processing chamber 21 and the processing chamber 21. The partition plate 24 has a plurality of holes 24a.

The etching gas is supplied from the gas introduction pipe 15 to the plasma generation chamber 22. The etching gas supplied to the plasma generation chamber 22 is guided to the processing chamber 21 through a hole 24 a provided in the partition plate 24. Thereafter, the air is exhausted from the exhaust port 16 to the outside. In order to discharge the etching gas to the outside, the processing chamber 21 is evacuated by a vacuum pump (not shown). The processing chamber 21 is maintained at a higher vacuum than the plasma generation chamber 22.

A second electrode 25 is attached to the plasma generation chamber 22 at a position facing the partition plate 24, and a high-frequency power supply 27 supplies high-frequency power to the second electrode 25. Further, a ring-shaped permanent magnet 11 is disposed on the atmosphere side of the second electrode 25.

Next, in the plasma dry etching apparatus having the above configuration, the etching gas introduced into the plasma generating chamber 22 is exhausted from the hole 24 a of the partition plate 24, passes through the processing chamber 21, and is exhausted from the exhaust port 16.

At this time, when high-frequency power is applied to the second electrode 25 of the plasma generation chamber 22, when the permanent magnet 11 disposed in the vicinity of the second electrode 25 creates a magnetic field and an electric field, E ×
Ionization is promoted by the B drift, and high-density plasma is generated. The plasma generated in the plasma generation chamber 22 is
The workpiece 2 transported from the hole 24a of the partition plate 24 to the processing chamber 21 and placed on the stage 26 is etched.

The configuration of the apparatus for performing etching corresponding to a large-diameter workpiece will be described below using specific numerical values. Three ring-shaped permanent magnets 11 are arranged concentrically on the atmosphere side of the second electrode 25 of the plasma generation chamber 22. As a result, in the vicinity of the second electrode 25, E due to an electric field and a magnetic field formed near the electrode 25.
× B drift occurs, but no uneven distribution of plasma occurs.
This is because the permanent magnets are arranged in a ring shape. Of the magnetic fields formed near the second electrode 25, the second
This is because the magnetic field component of the electrode 25 in the circumferential direction is zero. Therefore, uniform plasma can be generated over a large area.

Next, the surface magnetic field strength of the ring-shaped permanent magnet 11 is 3000 gauss, the distance between the ring-shaped permanent magnets 11 is 50 mm, the distance from the ring-shaped permanent magnet 11 to the second electrode 25 is 40 mm. The distance between the electrode 25 and the partition plate 24 is set to 80 mm.

The volume of the plasma generating chamber 22 is 10 liters, the volume of the processing chamber 21 is 50 liters, the effective evacuation speed is 100 liters / second, and the total area of the holes 24a of the partition plate 24 is about 7.0 cm ² . Configure. Using Cl ₂ gas as the etching gas, the pressure of the plasma generation chamber is set to 5 mT.
When set to orr, the pressure in the processing chamber 21 is about 1 mTorr.
r atmosphere. When discharge is performed in this state, the plasma density in the plasma generation chamber 22 becomes 5 × 10 ⁹ (pieces / c).
m ³ ) to about 5 × 10 ¹⁰ (pieces / cm ³ ), which is about one digit higher than that without a magnetic field. Further, the processing chamber 21 is kept in a high vacuum, and a fine pattern can be formed.

When the polysilicon material of the gate circuit in the semiconductor manufacturing was etched using the plasma dry etching apparatus configured as described above, the workpiece 2 having a size of 6 inches was etched at an etching rate of 100 nm.
/ Min, and a uniformity of 5%.

Although not shown, the uniformity of the etching rate can be further improved by arranging a cylindrical permanent magnet at the center of the concentric circle of the ring-shaped permanent magnet 11. In this case, the uniformity of the magnetic field can be adjusted by setting the surface magnetic field strength of the cylindrical permanent magnet to be higher or lower than 300 gauss of the surface magnetic field strength of the ring-shaped permanent magnet. As a result, uniform plasma is generated in the plasma generation chamber, so that uniform etching is performed.

Further, using the above device size and the surface magnetic field strength of the ring-shaped permanent magnet 11, the plasma generation chamber 2
2, a magnetic field intensity of 100 Gauss or more and 20 Gauss or less near the stage 26 of the processing chamber 21 are formed. as a result,
In the vicinity of the electrode 25 of the plasma generation chamber 22, the generation of plasma is promoted by the high magnetic field, and the high-density plasma is maintained. Becomes possible.

[Second Embodiment] Next, a plasma processing apparatus according to a second embodiment will be described. In the second embodiment, the chlorine dry gas and the sulfur hexafluoride gas are supplied to the plasma generation chamber 22 in the plasma dry etching apparatus described with reference to FIG.

Here, in the conventional plasma etching apparatus shown in FIG. 5, when etching is performed using sulfur hexafluoride gas or when etching is performed with sulfur hexafluoride gas added to chlorine gas. The etching rate is higher than when etching is performed only with chlorine gas.

This is because sulfur hexafluoride gas has higher reactivity with Si than chlorine gas. However, as described above, since sulfur hexafluoride gas has high reactivity, etching progresses isotropically, and there is a drawback that etching cannot be performed anisotropically in the vertical direction according to a mask pattern of a fine pattern. . Therefore, the object 2
Was cooled to about −100 ° C. to suppress chemical etching, thereby realizing vertical processing of polysilicon or the like.

However, since the above-described plasma dry etching apparatus has the plasma generation chamber 22 and the processing chamber 21, the direction toward the workpiece 2 due to the pressure difference between the plasma generation chamber 22 and the processing chamber 21. Since the etching of the processing object 2 is performed using the highly-reactive plasma,
Anisotropy can be given to the sulfur hexafluoride gas, and anisotropic etching can be realized for the processing target 2.

Here, referring to FIG. 2, the polysilicon and the photoresist film when the ratio of sulfur hexafluoride gas is gradually increased when the total flow rate of chlorine gas and sulfur hexafluoride gas is 70 sccm The relationship between the etching speeds will be described. In FIG. 2, the horizontal axis indicates the ratio of the sulfur hexafluoride gas to the total flow rate in%, and the vertical axis indicates the etching rate of polysilicon. As is clear from FIG. 2, it can be seen that as the proportion of the sulfur hexafluoride gas is increased, the etching speed for polysilicon can be gradually increased. At this time, an anisotropic etching shape was obtained.

[Third Embodiment] Next, a plasma processing apparatus according to a third embodiment will be described. In the third embodiment, the chlorine dry gas and the sulfur hexafluoride gas are supplied to the plasma generation chamber 22 in a pulsed manner in the plasma dry etching apparatus according to the second embodiment. The pulsed supply method is realized by using a pulse valve.

Here, the graph shown in FIG. 3 shows the plasma generation chamber 22 by the pulsed etching gas.
7 shows a result of calculating a pressure change between the pressure and the processing chamber 21 under ideal gas, isentropy, and one-dimensional flow.

Here, the supply etching gas is a mixed gas of chlorine gas and sulfur hexafluoride gas, the supply gas temperature is normal temperature, the supply gas pressure is 1 atm, and the diameter of the gas introduction pipe 15 is 0.
5 mm, the volume of the plasma generation chamber 22 is 10 liters, the volume of the processing chamber 21 is 50 liters, and the effective evacuation speed is 1
000 liter / sec, the area of the hole 24a of the partition plate 24 is about 7.0 cm ² , and the pulse gas introduction condition is an ON time of 2 m.
sec and the repetition time is 500 msec.

As shown in FIG. 2, the pressure in the plasma generation chamber 22 is maintained in a range of 1 × 10 ⁻³ (Torr) or more. On the other hand, the pressure in the processing chamber 21 is 1 × 10 ⁻⁴ (T
orr), and a pressure difference between the plasma generation chamber 22 and the processing chamber 21 is about one digit.

The hole 24a of the partition plate 24 used for the calculation was used.
Area 7.0 cm ² corresponds to a total area provided about 200 holes with a diameter of 2 mm. In other words, a hole of 2 mm has a diameter of 20c.
By arranging them at appropriate intervals in the range of m, the plasma can be uniformly transported to the object to be processed having a size of 8 inches.
Further, vertical etching by plasma having a direction component perpendicular to the surface of the processing object and fine processing with a small microloading effect can be performed without deteriorating the degree of vacuum in the processing chamber 21. Therefore, a large-diameter workpiece can be uniformly etched.

[Fourth Embodiment] Next, a plasma processing apparatus according to a fourth embodiment will be described. In the fourth embodiment, in addition to the configuration of the plasma dry etching apparatus described with reference to FIG. 1, a gas supply pipe 23 is further provided for introducing an etching gas into the processing chamber 21.

Using the plasma dry etching apparatus having the above configuration, chlorine gas is supplied to the plasma generation chamber 22 and sulfur hexafluoride gas is supplied to the processing chamber 21. Here, in the second embodiment, the chlorine gas and the sulfur hexafluoride gas are to be supplied to the plasma generation chamber 22. However, when the addition ratio of the sulfur hexafluoride gas in the plasma generation chamber 22 increases, the plasma Discharge in the generation chamber 22 becomes unstable.

This is because sulfur hexafluoride gas is a negative gas. Therefore, as shown in this embodiment, the chlorine gas is supplied only to the plasma generation chamber 22, the generated plasma is transported to the processing chamber 21, and the hexafluoride supplied to the processing chamber 21 using this plasma. The sulfur gas is turned into plasma. As a result, stable discharge is performed in the plasma generation chamber 22, and it becomes possible to perform stable etching of the object 2.

In the present embodiment, as described in the third embodiment, the supply of the chlorine gas and the supply of the sulfur hexafluoride gas are performed in a pulsed manner, as described in the third embodiment. The same operation and effect as described above can be obtained.

[Fifth Embodiment] Next, a plasma processing apparatus according to a fifth embodiment will be described. In the fifth embodiment, the plasma dry etching apparatus described with reference to FIG. 4 is used to supply sulfur hexafluoride gas to the plasma generation chamber 22 and supply chlorine gas to the processing chamber 21. Generally, when a sulfur hexafluoride gas is converted into a plasma, a polymer of S is generated. Therefore, the processing chamber 22
This polymer adheres to the inner wall of the vacuum vessel 1. The adhered polymer adheres as dust on the workpiece 2 during or after etching, and thus has a problem in performing fine processing.

In the present embodiment, since the etching is performed by supplying the sulfur hexafluoride gas to the plasma generation chamber 22 and supplying the chlorine gas to the processing chamber 21, the above-described problem hardly occurs. That is, when sulfur hexafluoride gas is discharged in the plasma generation chamber 22, a polymer is generated. However, since the pressure of the plasma generation chamber 22 is higher by one digit than that of the processing chamber 21, the polymer is generated up to the wall of the plasma generation chamber 22. Does not spread.
As a result, the polymer does not adhere to the inner wall of the vacuum vessel 1 and does not fall down onto the object to be processed as dust, so that clean etching can be performed.

In this embodiment, the same operation and effects as those of the third embodiment can be obtained by supplying the etching gas in a pulsed manner as described in the third embodiment.

[Sixth Embodiment] Next, a plasma processing apparatus according to a sixth embodiment will be described. In the sixth embodiment, the chlorine dry gas and the oxygen gas are supplied to the plasma generation chamber 22 in the plasma dry etching apparatus described with reference to FIG. in this way,
Since the plasma is transported onto the processing target 2 using the pressure difference in the two-chamber structure having the plasma generation chamber 22 and the processing chamber 21, the plasma and the radicals reach the bottom inside the fine pattern. As a result, the conventional microloading effect when an etching gas of a mixture of chlorine gas and oxygen gas is used is suppressed, and the etching characteristics can be made the same in the fine pattern and in the region other than the fine pattern. As a result, a fine pattern can be etched with high precision.

[Seventh Embodiment] Next, a plasma processing apparatus according to a seventh embodiment will be described. In the seventh embodiment, an oxygen gas is supplied to the plasma generation chamber 22 and a chlorine gas is supplied to the processing chamber 21 using the plasma dry etching apparatus described with reference to FIG. As described above, since the plasma is not generated using the chlorine gas as the process gas, the plasma generation chamber 2 is not used.
2, it is possible to suppress the generation of dust and contamination, and it is possible to perform a highly accurate etching process on a fine pattern. In the above-described first to seventh embodiments, a parallel plate type plasma generator has been described as a type of generating plasma. However, the present invention is not necessarily limited to this type. For example, an inductive coupling type, an IPC type, an ECR type, a magnetron type The same operation and effect can be obtained by using a plasma generator of a system or the like.

Therefore, it should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0070]

According to one aspect of the plasma processing apparatus according to the present invention, in a plasma processing apparatus in which the inside of a vacuum vessel is divided into a plasma generation chamber and a processing chamber by a partition plate, chlorine is added to the plasma generation chamber. When the gas and the sulfur hexafluoride gas are supplied, a highly directional plasma toward the object to be processed is generated due to a pressure difference generated between the plasma generation chamber and the processing chamber. Thus, it is possible to give the highly isotropic sulfur hexafluoride gas directionality toward the object to be processed. As a result, even when a highly reactive sulfur hexafluoride gas is used, anisotropic etching in the depth direction of the object can be realized.

Preferably, the chlorine gas is supplied constantly, and the sulfur hexafluoride gas is supplied in a pulsed manner. Thus, by supplying the sulfur hexafluoride gas in a pulsed manner, when the sulfur hexafluoride gas is supplied, the pressure in the plasma generation chamber temporarily increases, and the pressure between the plasma generation chamber and the processing chamber is increased. The difference can be further increased.
As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

Next, according to another aspect of the plasma processing apparatus according to the present invention, chlorine gas is supplied to the plasma generation chamber and sulfur hexafluoride gas is supplied to the processing chamber.
When sulfur hexafluoride gas is a negative gas, the plasma discharge becomes unstable when sulfur hexafluoride gas is supplied to the plasma generation chamber, but chlorine gas is supplied to the plasma generation chamber. Can be performed in a stable state, and a stable surface treatment of the object can be performed.

Preferably, the supply of the chlorine gas and the supply of the sulfur hexafluoride gas are performed in a pulsed manner. As described above, by supplying the chlorine gas and the sulfur hexafluoride gas in a pulsed manner, when the chlorine gas and the sulfur hexafluoride gas are supplied, the pressure of the plasma generation chamber is temporarily reduced. And the pressure difference between the plasma generation chamber and the processing chamber can be further increased. As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

Next, according to still another aspect of the plasma processing apparatus according to the present invention, sulfur hexafluoride gas is supplied to the plasma generation chamber, and chlorine gas is supplied to the processing chamber, so that the conventional plasma processing apparatus can be used. Sulfur fluoride gas becomes S
Polymer is generated, the polymer adheres to the inner wall of the processing chamber, and the adhered polymer adheres as dust during or after the etching of the processing object. Although there was a problem in performing this, such a problem is less likely to occur.

When the sulfur hexafluoride gas is discharged in the plasma generation chamber, a polymer film is formed. However, since the pressure in the plasma generation chamber is higher than the pressure in the processing chamber, the polymer film is diffused to the wall of the plasma generation chamber. Never. As a result, the polymer film does not adhere to the walls of the processing chamber and does not fall down onto the object as dust, so that extremely clean etching of the object can be realized.

Preferably, the chlorine gas is supplied constantly, and the sulfur hexafluoride gas is supplied in a pulsed manner.
Thus, by supplying the sulfur hexafluoride gas in a pulsed manner, when the sulfur hexafluoride gas is supplied, the pressure in the plasma generation chamber temporarily increases, and the pressure between the plasma generation chamber and the processing chamber is increased. The difference can be further increased. As a result, the directionality from the plasma generation chamber toward the processing chamber is further increased, so that even when a highly reactive sulfur hexafluoride gas is added, it is possible to realize higher performance anisotropic etching. Become.

According to still another aspect of the plasma processing apparatus according to the present invention, by supplying chlorine gas and oxygen gas to the plasma generating chamber, the plasma processing chamber has a plasma generating chamber and a processing chamber. Due to the pressure difference between the generation chamber and the processing chamber, the plasma generated in the plasma generation chamber is transported to the processing chamber, so that plasma and radicals reach the bottom inside the fine pattern of the object to be processed. As a result, the etching characteristics are the same in the fine pattern and the region other than the fine pattern, whereby the microloading effect, which has conventionally been a problem, can be reduced, and the workpiece can be etched accurately.

According to still another aspect of the plasma processing apparatus according to the present invention, by supplying oxygen gas to the plasma generation chamber, the oxygen gas, which is the process gas, does not generate plasma. Generation of dust and contamination in the chamber can be prevented, and highly accurate etching of the object can be performed.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment and a sixth embodiment of the present invention;
FIG. 2 is a cross-sectional configuration view schematically showing a plasma dry etching apparatus used in the embodiment.

FIG. 2 is a diagram for explaining effects according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining effects in the second, fourth, and sixth embodiments of the present invention.

FIG. 4 is a sectional configuration view schematically showing a plasma dry etching apparatus used in Embodiments 4, 5, and 7 of the present invention.

FIG. 5 is a sectional view showing a plasma processing apparatus of a first conventional example.

6 is a diagram showing a plasma density of the plasma processing apparatus shown in FIG.

FIG. 7 is a schematic diagram showing a plasma drift state in a conventional example.

FIG. 8 shows a second conventional plasma processing apparatus.
FIG. 6 is a diagram showing a radial distribution of a lateral magnetic flux density B⊥ on the electrode surface of FIG.

FIG. 9 is an explanatory diagram for explaining drift of plasma in another conventional plasma processing apparatus.

FIG. 10 is a schematic configuration diagram showing a dry etching apparatus of a conventional plasma processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum container, 2 to-be-processed object, 11 permanent magnet, 15
Gas inlet tube, 16 exhaust port, 21 processing chamber, 22 plasma generation chamber, 24 partition plate, 24a hole, 25 second electrode, 26 stage, 27, 28 high frequency power supply.

Continued on the front page (72) Inventor Kenji Shintani 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (8)

[Claims] 1. A processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum vessel, and a second electrode disposed in the vacuum vessel so as to face the first electrode. A plasma processing apparatus, comprising: a plasma generation chamber having: a partition plate provided between the processing chamber and the plasma generation chamber, the partition plate having a hole communicating from the plasma generation chamber to the processing chamber. A plasma processing apparatus for performing a surface treatment of the object by supplying a chlorine gas and a sulfur hexafluoride gas to a plasma generation chamber. 2. The plasma processing apparatus according to claim 1, wherein the chlorine gas is supplied constantly, and the sulfur hexafluoride gas is supplied in a pulsed manner. 3. A processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum vessel, and a second electrode disposed in the vacuum vessel so as to face the first electrode. A plasma processing apparatus, comprising: a plasma generation chamber having: a partition plate provided between the processing chamber and the plasma generation chamber, the partition plate having a hole communicating from the plasma generation chamber to the processing chamber. A plasma processing apparatus for supplying a chlorine gas to a plasma generation chamber and supplying a sulfur hexafluoride gas to the processing chamber to perform a surface treatment on the object to be processed. 4. The plasma processing apparatus according to claim 3, wherein the supply of the chlorine gas and the supply of the sulfur hexafluoride gas are performed in a pulsed manner. 5. A processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum vessel, and a second electrode disposed in the vacuum vessel so as to face the first electrode. A plasma processing apparatus, comprising: a plasma generation chamber having: a partition plate provided between the processing chamber and the plasma generation chamber, the partition plate having a hole communicating from the plasma generation chamber to the processing chamber. A plasma processing apparatus for supplying a sulfur hexafluoride gas to a plasma generation chamber and supplying a chlorine gas to the processing chamber to perform a surface treatment on the object to be processed. 6. The plasma processing apparatus according to claim 5, wherein the supply of the sulfur hexafluoride gas and the supply of the chlorine gas are performed in a pulsed manner. 7. A processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum vessel, and a second electrode disposed in the vacuum vessel so as to face the first electrode. A plasma processing apparatus, comprising: a plasma generation chamber having; and a partition plate provided between the processing chamber and the plasma generation chamber and having a hole communicating with the processing chamber from the plasma generation chamber. A plasma processing apparatus for performing a surface treatment of the object to be processed by supplying chlorine gas and oxygen gas to a generation chamber. 8. A processing chamber in which a first electrode on which an object to be processed is placed is disposed in a vacuum container, and a second electrode disposed in the vacuum container so as to face the first electrode. A plasma processing apparatus, comprising: a plasma generation chamber having; and a partition plate provided between the processing chamber and the plasma generation chamber and having a hole communicating with the processing chamber from the plasma generation chamber. A plasma processing apparatus for supplying oxygen gas to a generation chamber and supplying chlorine gas to the processing chamber to perform surface treatment on the object to be processed.