JP3083745B2 - Plasma processing equipment - Google Patents

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 such as dry etching, sputtering, and plasma CVD, and more particularly to a high frequency induction type plasma processing apparatus.

[0002]

2. Description of the Related Art In recent years, in response to miniaturization of semiconductor devices,
In dry etching technology, in order to realize processing with a high aspect ratio, etc., and in plasma CVD technology, in order to realize embedding with a high aspect ratio, plasma processing in a higher vacuum is required.

For example, in the case of dry etching, when high-density plasma is generated in a high vacuum, the probability that ions collide with neutral gas particles and the like in an ion sheath formed on the substrate surface decreases. The directionality of the ions is aligned toward the substrate, and the ionization degree is high, so that the ratio of the ion flux reaching the substrate to the incident particle flux of the neutral radical increases. Therefore, the etching anisotropy is enhanced, and processing with a high aspect ratio becomes possible.

In the case of plasma CVD,
When high-density plasma is generated in a high vacuum, a fine pattern is buried and a flattening effect is obtained by a sputtering effect of ions, so that a high aspect ratio can be buried.

As one of plasma processing apparatuses capable of generating high-density plasma in a high vacuum, a high-frequency induction system in which plasma is generated in a vacuum vessel by applying a high-frequency voltage to a planar vortex discharge coil is used. 2. Description of the Related Art Plasma processing apparatuses are known. This type of plasma processing apparatus generates a high-frequency magnetic field in a vacuum vessel, generates an induced electric field in the vacuum vessel by the high-frequency magnetic field, accelerates electrons, and generates plasma. For example, high-density plasma can be generated even in a high vacuum, and a sufficient processing speed can be obtained.

FIG. 10 shows an example of a high frequency induction type plasma processing apparatus. 10, while introducing suitable gas into the vacuum chamber 1 was evacuated, while the vacuum chamber 1 maintained an appropriate pressure, the discharge coil high-frequency power supply 2 is adhered to the high-frequency voltage to the dielectric plate 3 plane When the voltage is applied to the spiral discharge coil 4, plasma is generated in the vacuum vessel 1, and etching, deposition, and the like are performed on the substrate 6 placed on the electrode 5.
Plasma treatment such as surface modification can be performed. At this time, as shown in FIG. 10, by applying a high-frequency voltage to the electrode 5 from the electrode high-frequency power supply 7, the ion energy reaching the substrate 6 can be controlled.

[0007]

However, FIG.
In the conventional method shown in the above, as the processing is repeated,
There is a problem that the temperature of the dielectric plate 3 rises due to the heating by the high-energy ions colliding with the dielectric plate 3, the adhesion between the discharge coil 4 and the dielectric plate 3 is detached, and the discharge coil 4 is deformed. From experiments, it has been found that the temperature of the dielectric plate 3 rises to 200 ° C. when discharging is performed continuously for 1 hour using Ar gas.

[0008] Therefore, as shown in FIG. 11, bonding the discharge coil 4 to the ceramic plate or a glass plate 15, it has been considered to provide a ceramic plate or a glass plate 15 on the dielectric plate 3, heating This causes a problem that the ceramic plate or the glass plate 15 breaks due to the expansion of the discharge coil 4.

When the discharge coil 4 is deformed, the distribution of the plasma density in the vacuum vessel 1 changes, and the in-plane uniformity of the process deteriorates. In addition, a ceramic plate or a glass plate 1
When the wire 5 is broken, not only the deformation of the discharge coil 4 but also an abnormal discharge in the air may be caused.

The present invention has been made in view of the above-described conventional problems, and has as its object to provide a plasma processing apparatus that stably fixes a discharge coil and does not generate abnormal discharge in the atmosphere.

[0011]

A plasma processing apparatus according to the present invention comprises a high-frequency power supply and a planar vortex discharge coil, and applies a high-frequency voltage to the discharge coil by the high-frequency power supply to form a vacuum through a dielectric plate. A plasma processing apparatus for generating a high-frequency magnetic field in a container, accelerating electrons by an induced electric field by the high-frequency magnetic field, generating plasma in a vacuum container, and processing a substrate, wherein a ceramic plate is provided on the dielectric plate.
And the flat-plate spiral discharge coil is provided in a discharge coil fixing groove formed in the ceramic plate ,
Even if the temperature of the dielectric plate rises due to heating by high-energy ions colliding with the dielectric plate, the close contact between the discharge coil and the ceramic plate is not impaired, and the discharge coil is not deformed. In addition, even if the discharge coil expands due to an increase in temperature, the ceramic plate is unlikely to crack because the discharge coil and the ceramic plate are not bonded.

The ceramic plate has a thickness of 5 mm or less,
It is preferable to use a free-cutting ceramic having an area of 350 cm ² or less. In consideration of power efficiency, the thickness of the ceramic plate on which the discharge coil fixing groove is formed is preferably thin. This is the case, for example, in J. Hopwood, "Planar RF induction
plasma coupling efficiency ", Plasma Souces Sci.Te
chnol. 3 (1994), pp. 460-464.
If the area of the ceramic plate is 350 cm ² or less, the material of the ceramic plate is an inexpensive free-cutting ceramic having a thickness of 5 cm.
It has been confirmed that the ceramic plate does not crack even if it is less than mm. Therefore, the area of the ceramic plate is 3
In the case of 50 cm ² or less, the material of the ceramic plate is made of free-cutting ceramic and the thickness thereof is set to 5 mm or less, whereby a low-cost and excellent power efficiency plasma processing apparatus can be provided.

Preferably, a flat heater is provided between the ceramic plate and the dielectric plate. By doing so,
The temperature of the dielectric plate can be stabilized, dust can be prevented, and the maintenance cycle can be improved.

Further, the planar spiral discharge coil may be provided on a glass plate provided with a discharge coil fixing groove. Thus, the same effect can be obtained when a glass plate is used instead of a ceramic plate. Also, in the case of a glass plate, a thickness of 5 mm or less can provide a plasma processing apparatus excellent in power efficiency, and a similar effect can be obtained by providing a planar heater between the glass plate and the dielectric plate. Can be

Further, the glass plate between the tabular volute discharge coil, a discharge coil fixing groove is formed and arranged into a plurality of divided the machinable ceramic board, machinable ceramic plate and the dielectric plate Alternatively, by providing a ceramic plate, even if the temperature of the dielectric plate rises due to heating by high-energy ions colliding with the dielectric plate, the adhesion between the discharge coil and the free-cutting ceramic plate is not impaired, and the discharge coil is not damaged. In addition to the above-described effect of not being deformed, even if the free-cutting ceramic plate is divided, the glass plate or the ceramic plate is provided, so that abnormal discharge does not occur in the atmosphere.

Also, when the total area of the plurality of divided free-cutting ceramic plates is greater than 350 cm ² , the thickness of each free-cutting ceramic plate is 5 mm or less, and By setting the area of the plate to 350 cm ² or less and the thickness of the glass plate or ceramic plate to 5 mm or less, cracking of the free-cutting ceramic plate can be prevented in the same manner as described above, and inexpensive and excellent in power efficiency. A processing device can be provided and a similar effect can be obtained by providing a planar heater between the glass or ceramic plate and the dielectric plate.

In the above configuration, when the second ceramic plate or the glass plate is provided above the flat spiral discharge coil, the discharge coil and the ceramic plate or the glass plate provided with the discharge coil fixing groove can be separated. Since the adhesion is further increased, the deformation of the discharge coil can be more effectively prevented. If a part or all of the planar vortex discharge coil is a multiple vortex, a plasma processing apparatus having excellent matching characteristics can be provided.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a plasma processing apparatus according to the present invention will be described with reference to FIGS.

In FIG. 1, the gas is evacuated while introducing an appropriate gas into the vacuum vessel 1, and while maintaining the inside of the vacuum vessel 1 at an appropriate pressure, a high-frequency voltage is applied by a high-frequency power supply 2 for a discharge coil to fix the discharge coil. When applied to a planar vortex discharge coil 4 provided on a 5 mm thick ceramic (alumina) plate 8 provided with a groove 9, plasma is generated in the vacuum vessel 1 and placed on the electrode 5. Plasma processing such as etching, deposition, and surface modification can be performed on the substrate 6. At this time, as shown in FIG. 1, by applying a high-frequency voltage to the electrode 5 from the electrode high-frequency power supply 7, the ion energy reaching the substrate 6 can be controlled. In addition, 3 is a dielectric plate.

The substrate 6 with a silicon oxide film having a thickness of 500 nm is subjected to gas type and its flow rate, pressure, high-frequency power applied to a flat thin discharge coil, and high-frequency power applied to an electrode by C ₄ , respectively.
F ₈ / H ₂ = 50/15 sccm, 10 mTorr, 1
When a plurality of wafers were continuously etched under the conditions of 000 W and 300 W, the temperature of the dielectric board 3 increased due to heating by high energy ions colliding with the dielectric board 3, and the temperature of the dielectric board 3 reached 200 ° C. at the tenth wafer. . However, the discharge coil 4
There was no loss of the adhesion between the discharge coil 4 and the ceramic plate 8, and the discharge coil 4 was not deformed. In addition, despite the expansion of the discharge coil 4 due to the rise in temperature, no cracking of the ceramic plate 8 occurred.

In the above-described first embodiment, an example has been described in which alumina is used as the material of the ceramic plate 8, but other materials such as zirconia may be used. In particular, if the area of the ceramic plate 8 is 350 cm ² or less, the material of the ceramic plate 8 is an inexpensive free-cutting ceramic having a thickness of 5 cm.
It has been confirmed that, even when the thickness is not more than mm, cracking of the ceramic plate 8 does not occur. Therefore, when the area of the ceramic plate 8 is 350 cm ² or less, the material of the ceramic plate 8 is made of a free-cutting ceramic, so that it is possible to provide a plasma processing apparatus which is inexpensive and has excellent power efficiency.

Further, as shown in FIG.
A flat heater 10 may be provided between the dielectric plate 3 and the dielectric plate 3. In this case, the temperature of the dielectric plate 3 can be stabilized, dust can be prevented, a maintenance cycle can be increased, and reproducibility can be improved.

[0023] Examples of commonly known free-cutting ceramics include "Macerite" of Mitsui Mining Materials Co., Ltd. and "Photoveil" of Sumikin Hoton Ceramics Co., Ltd.

Next, a second embodiment of the plasma processing apparatus of the present invention will be described with reference to FIGS.

In FIG. 3, exhaust is performed while introducing an appropriate gas into the vacuum vessel 1, and while maintaining the inside of the vacuum vessel 1 at an appropriate pressure, a high frequency voltage is applied by the high frequency power supply 2 for the discharge coil to fix the discharge coil. When the voltage is applied to the planar vortex discharge coil 4 provided on the glass plate 11 having a thickness of 5 mm and provided with the groove 9, plasma is generated in the vacuum vessel 1 and the electrode 5
Plasma processing such as etching, deposition, and surface modification can be performed on the substrate 6 placed thereon. At this time, as shown in FIG.
By applying a high frequency voltage, the ion energy reaching the substrate 6 can be controlled. In addition, 3 is a dielectric plate.

The substrate 6 having a silicon oxide film having a thickness of 500 nm is subjected to gas species, its flow rate, pressure, high-frequency power applied to a flat thin discharge coil, and high-frequency power applied to an electrode by C _4.
F ₈ / H ₂ = 50/15 sccm, 10 mTorr, 1
When a plurality of wafers were continuously etched under the conditions of 000 W and 300 W, the temperature of the dielectric board 3 increased due to heating by high energy ions colliding with the dielectric board 3, and the temperature of the dielectric board 3 reached 200 ° C. at the tenth wafer. . However, the discharge coil 4
The adhesion between the glass plate 11 and the discharge coil 4 was not damaged. In addition, despite the expansion of the discharge coil 4 due to the rise in temperature, no cracks occurred in the glass plate 11.

In the second embodiment, the case where the glass plate 11 is arranged in contact with the dielectric plate 3 has been described. However, as shown in FIG. In this case, the temperature of the dielectric plate 3 can be stabilized, dust can be prevented, a maintenance cycle can be increased, and reproducibility can be improved.

Next, a third embodiment of the plasma processing apparatus of the present invention will be described with reference to FIGS.

In FIG. 5, exhaust is performed while introducing an appropriate gas into the vacuum vessel 1, and while maintaining the inside of the vacuum vessel 1 at an appropriate pressure, a high frequency voltage is applied by the high frequency power supply 2 for the discharge coil to fix the discharge coil. When applied to the planar vortex discharge coil 4 provided on the 5 mm thick free-cutting ceramic plate 12 provided with the groove 9, plasma is generated in the vacuum vessel 1 and placed on the electrode 5. Plasma processing such as etching, deposition, and surface modification can be performed on the substrate 6 thus etched. At this time, as shown in FIG. 5, by applying a high-frequency voltage to the electrode 5 from the electrode high-frequency power source 7, the ion energy reaching the substrate 6 can be controlled. In addition, 3 is a dielectric plate. The free-cutting ceramic plate 12 is divided into four parts as shown in FIG. 6, and the area of each free-cutting ceramic plate is 350 cm ² or less. Further, a glass plate or a ceramic plate 13 is provided between the free-cutting ceramic plate 12 and the dielectric plate 3.

The substrate 6 having a silicon oxide film with a thickness of 500 nm is subjected to gas type, its flow rate, pressure, high-frequency power applied to a flat thin discharge coil, and high-frequency power applied to an electrode by C _4.
F ₈ / H ₂ = 50/15 sccm, 10 mTorr, 1
When a plurality of wafers were continuously etched under the conditions of 000 W and 300 W, the temperature of the dielectric board 3 increased due to heating by high energy ions colliding with the dielectric board 3, and the temperature of the dielectric board 3 reached 200 ° C. at the tenth wafer. . However, the discharge coil 4
There was no loss in the close contact between the substrate and the free-cutting ceramic plate 12, and the discharge coil 4 was not deformed.
Further, despite the expansion of the discharge coil 4 due to the rise in temperature, no cracking of the free-cutting ceramic plate 12 occurred.
Further, since the glass plate or the ceramic plate 13 is provided between the free-cutting ceramic plate 12 and the dielectric plate 3, abnormal discharge occurs in the atmosphere despite the fact that the free-cutting ceramic plate 12 is divided. I never did.

[0031] If the area of the free-cutting ceramic plate is greater than 350 cm ^2, it is easy cracking of machinable ceramic plate is generated, also, the area of the free-cutting ceramic plate is equal to or 350 cm ² or less, a thickness Is not more than 5 mm, no cracking of the free-cutting ceramic plate occurs.
Therefore, by setting the area of each of the divided free-cutting ceramic plates to 350 cm ² or less, it is possible to prevent cracking of each of the free-cutting ceramic plates and to configure an inexpensive and power-efficient plasma processing apparatus. Was completed. Also,
As shown in FIG. 7, a planar heater 10 may be provided between the glass plate or ceramic plate 13 and the dielectric plate 3, in which case the temperature of the dielectric plate 3 is stabilized, dust is prevented, and the maintenance cycle is increased. And reproducibility can be improved.

In each of the above embodiments, if the second ceramic plate or the glass plate is provided above the flat spiral discharge coil, the ceramic plate or the glass plate provided with the discharge coil and the discharge coil fixing groove is provided. Therefore, the deformation of the discharge coil can be more effectively prevented. An example in which this configuration is applied to the first embodiment is shown in FIG. 8 as a fourth embodiment. In FIG. 8, reference numeral 14 denotes a second ceramic plate or a glass plate.
If a part or all of the planar vortex discharge coil is a multiple vortex, a plasma processing apparatus having excellent matching characteristics can be provided. FIG. 9 shows the configuration of a free-cutting ceramic plate 12 according to the fifth embodiment in the case where multiple spiral coils are used as the planar spiral discharge coil.

In the third and fifth embodiments, an example has been described in which the number of divisions of the free-cutting ceramic plate is four, but the number of divisions is not limited to four.

[0034]

According to the plasma processing apparatus of the present invention, as apparent from the above description , the ceramic plate is placed on the dielectric plate.
And the flat-plate vortex discharge coil is provided on the ceramic plate on which the discharge coil fixing groove is formed, so even if the temperature of the dielectric plate rises due to heating by high energy ions colliding with the dielectric plate, Since the adhesion between the discharge coil and the ceramic plate is not impaired, the discharge coil is not deformed, and even if the discharge coil expands due to an increase in temperature, the discharge coil and the ceramic plate are not bonded. This has the effect that cracking of the ceramic plate hardly occurs.

Further, by using a free-cutting ceramic as the material of the ceramic plate and setting its thickness to 5 mm or less, it is possible to provide a plasma processing apparatus which is inexpensive and excellent in power efficiency.

Further, by providing a planar heater between the ceramic plate and the dielectric plate, the temperature of the dielectric plate can be stabilized, dust can be prevented, and the maintenance cycle can be improved.

A similar effect can be obtained when a glass plate is used in place of a ceramic plate, and a plasma processing apparatus excellent in power efficiency can be provided by setting the thickness of the glass plate to 5 mm or less. The same effect can be obtained by providing a planar heater between the glass plate and the dielectric plate.

Further, the glass plate between the tabular volute discharge coil, a discharge coil fixing groove is formed and arranged into a plurality of divided the machinable ceramic board, machinable ceramic plate and the dielectric plate Alternatively, if a ceramic plate is provided, the same effect as described above can be obtained, and even if the free-cutting ceramic plate is divided, abnormal discharge does not occur in the atmosphere because the glass plate or the ceramic plate is provided.

When the total area of the plurality of divided free-cutting ceramic plates is larger than 350 cm ² , the thickness of each free-cutting ceramic plate is 5 mm or less, and each free-cutting ceramic plate has a thickness of 5 mm or less. By setting the area of the plate to 350 cm ² or less and the thickness of the glass plate or ceramic plate to 5 mm or less, cracking of the free-cutting ceramic plate can be prevented in the same manner as described above, and inexpensive and excellent in power efficiency. A processing device can be provided and a similar effect can be obtained by providing a planar heater between the glass or ceramic plate and the dielectric plate.

In the above arrangement, when a second ceramic plate or a glass plate is provided above the flat spiral discharge coil, the discharge coil and the ceramic plate or the glass plate provided with the discharge coil fixing groove can be separated. Since the adhesion is further increased, the deformation of the discharge coil can be more effectively prevented.

If a part or all of the planar vortex discharge coil is a multiple vortex, a plasma processing apparatus having excellent matching characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a modified configuration example of the plasma processing apparatus of the embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a modified configuration example of the plasma processing apparatus of the embodiment.

FIG. 5 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a third embodiment of the present invention.

FIG. 6 is a plan view showing a configuration of a free-cutting ceramic plate in the plasma processing apparatus of the embodiment.

FIG. 7 is a cross-sectional view showing a modified configuration example of the plasma processing apparatus of the embodiment.

FIG. 8 is a sectional view illustrating a configuration of a plasma processing apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a plan view showing a configuration of a free-cutting ceramic plate in a plasma processing apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a schematic configuration of a conventional plasma processing apparatus.

FIG. 11 is a cross-sectional view illustrating a schematic configuration of another conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 High frequency power supply for discharge coil 3 Dielectric plate 4 Flat spiral discharge coil 5 Electrode 6 Substrate 8 Ceramic plate 9 Discharge coil fixing groove 10 Flat heater 11 Glass plate 12 Free-cutting ceramic plate divided into a plurality 13 glass plate or ceramic plate 14 second ceramic plate or glass plate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/205 H01L 21/205 21/3065 21/31 C 21/31 21/302 B (58) Field surveyed (Int.Cl. . ^7, DB name) H05H 1/46 C23C 16/50 C23F 4/00 H01L 21/3065

Claims (12)

(57) [Claims] 1. A high-frequency power supply and a planar vortex discharge coil are provided, and a high-frequency voltage is applied to the discharge coil by the high-frequency power supply to generate a high-frequency magnetic field in a vacuum vessel through a dielectric plate. A plasma processing apparatus for processing a substrate by accelerating electrons by an induced electric field and generating plasma in a vacuum vessel, wherein a ceramic is disposed on the dielectric plate.
A ceramic plate is provided and formed on the ceramic plate.
The flat spiral discharge coil is provided in the discharge coil fixing groove.
A plasma processing apparatus. 2. The plasma processing according to claim 1, wherein the thickness of the ceramic plate is 5 mm or less, the area of the ceramic plate is 350 cm ² or less, and the material of the ceramic plate is a free-cutting ceramic. apparatus. 3. The plasma processing apparatus according to claim 1, wherein a planar heater is provided between the ceramic plate and the dielectric plate. 4. A high-frequency power supply and a planar vortex discharge coil, and a high-frequency power supply applies a high-frequency voltage to the discharge coil to generate a high-frequency magnetic field in a vacuum vessel through a dielectric plate. A plasma processing apparatus for processing a substrate by accelerating electrons by an induced electric field and generating plasma in a vacuum vessel, wherein a glass plate is provided on the dielectric plate.
And a discharge coil formed on the glass plate.
A plasma processing apparatus characterized in that the planar vortex discharge coil is provided in a groove for fixing a nozzle . 5. The plasma processing apparatus according to claim 4, wherein the thickness of the glass plate is 5 mm or less. 6. The plasma processing apparatus according to claim 4, wherein a planar heater is provided between the glass plate and the dielectric plate. 7. A high-frequency power supply and a planar vortex discharge coil are provided, and a high-frequency voltage is applied to the discharge coil by the high-frequency power supply to generate a high-frequency magnetic field in a vacuum vessel through a dielectric plate. A plasma processing apparatus for processing a substrate by accelerating electrons with an induced electric field and generating plasma in a vacuum vessel, wherein a flat vortex discharge coil is formed into a plurality of discharge coil fixing grooves and divided. On a free-cutting ceramic plate.
A plasma processing apparatus, wherein a glass plate or a ceramic plate is provided between the dielectric plate and the dielectric plate. 8. The total area of the plurality of divided free-cutting ceramic plates is greater than 350 cm ² , the thickness of each free-cutting ceramic plate is 5 mm or less, and the area of each free-cutting ceramic plate is The plasma processing apparatus according to claim 7, wherein is less than or equal to 350 cm ² . 9. The glass or ceramic plate having a thickness of 5
The plasma processing apparatus according to claim 7, wherein the diameter is equal to or less than mm. 10. The plasma processing apparatus according to claim 7, wherein a planar heater is provided between the glass plate or the ceramic plate and the dielectric plate. 11. A second coiled coil above the planar vortex discharge coil.
8. The plasma processing apparatus according to claim 1, wherein said ceramic plate or glass plate is provided. 12. The plasma processing apparatus according to claim 1, wherein a part or the whole of the planar spiral discharge coil has a multiple spiral shape.