JP3089925B2 - Plasma processing apparatus and plasma processing method using the apparatus - 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 and a plasma processing method using the apparatus, and more particularly, to a plasma processing apparatus and apparatus for performing plasma processing such as etching and thin film formation on a sample. And a plasma processing method using the same.

[0002]

2. Description of the Related Art In recent years, a plasma is generated by supplying a high frequency or the like into a vacuum vessel under a reduced pressure to generate a gas discharge, and the plasma is irradiated onto a sample surface to perform processing such as etching and thin film formation. The method of performing and the apparatus
Research and development are being actively pursued as indispensable for the production of highly integrated semiconductor elements and the like.

As such an apparatus, a parallel plate type reactive ion etching (RIE; Reactive I
on Etching) apparatus, a parallel plate type sputtering apparatus, a magnetron RIE apparatus using a high frequency and a magnetic field, and the like. Further, as a device capable of generating highly active plasma in a low gas pressure region by using a microwave and a magnetic field, a magnetic field microwave plasma processing device and an electron cyclotron resonance excitation (ECR: Electron C
(Yclotron Resonance) Plasma processing equipment is particularly promising in the future.

[0004] When plasma treatment is performed on a sample surface using the above-described various devices, in particular, members exposed to plasma, such as a reaction vessel, an anti-adhesion plate, a target, and an electrode for power introduction, receive heat by receiving plasma irradiation. As the number of samples processed increases, the temperature of the member gradually increases. This causes a problem that the plasma processing speed and the etching selectivity change. For example, in an oxide film etching apparatus, a gas such as CF ₄ is used as an etching gas, and C, which is a decomposition product, usually adheres to the plasma generation chamber. The amount of C deposited depends on the temperature, and decreases as the temperature of the member increases. For this reason, under continuous processing conditions, the amount of C attached to the plasma generation chamber member decreases, and instead, the amount of C attached to the sample increases, and the etching rate of the sample decreases.

In order to solve the above problem, a plasma etching method for controlling the temperature of a member exposed to plasma to a constant value using a heat medium (Japanese Patent Laid-Open No. 4-256316).
Also, a plasma processing apparatus in which the inner wall of a reaction vessel is covered with a member that generates the Peltier effect (Japanese Patent Laid-Open No. 4-209528) has been proposed.

[0006]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Laid-Open No. 4-2
In the method described in Japanese Patent No. 56316, for example, the plasma generation chamber has a double structure, a heating medium of about 80 ° C. is circulated therebetween, the plasma generation chamber is maintained at a set temperature, and the etching rate and the selectivity are kept constant. Trying to.

However, in such temperature control by circulation of the heat medium, the temperature of the wall of the plasma generation chamber is saturated because the heat transport amount of the heat medium is smaller than the heat generated in the plasma generation chamber. When the temperature of the heat medium is set low so as to be a preferable temperature condition for the plasma processing, it takes time until the temperature of the inner wall is saturated, and during this time, the plasma processing speed changes. On the other hand,
If the temperature of the heat medium is set to be slightly higher so that the temperature of the inner wall becomes a favorable temperature condition for plasma processing as soon as possible, the temperature of the inner wall gradually increases even after the temperature of the inner wall becomes a favorable temperature condition for plasma processing. However, there has been a problem that the saturation temperature becomes higher than expected, and favorable plasma processing conditions cannot be obtained.

[0008] Similar problems have also been encountered with constituent members in a reaction vessel, such as a target of a sputtering apparatus.

In the plasma processing apparatus described in Japanese Patent Application Laid-Open No. 4-209528, the inner wall of the reaction vessel is covered with a member generating the Peltier effect, and the endothermic reaction of the member causes the reaction during the plasma processing. Although the vessel is cooled, the temperature of the inner wall of the reaction vessel is not accurately controlled to a desired set temperature,
Again, there was a problem that it was difficult to maintain the temperature of the reaction vessel at a desired temperature.

[0010] Also, in the case of a ground electrode in a parallel plate type RIE apparatus, the temperature of the lower surface of the ground electrode may fluctuate by 20 ° C or more, and in this case, there is a problem that reproducibility of the process cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to quickly set and maintain the temperature of a portion exposed to plasma to a desired temperature suitable for processing and to make the plasma processing speed constant. It is an object of the present invention to provide a plasma processing apparatus capable of improving the reproducibility of an etching process and a plasma processing method using the apparatus.

[0012]

FIG. 1 is a graph showing heat transfer coefficients of various types and refrigerants (heat mediums). As is clear from FIG. 1, the heat transfer coefficient of the liquid phase is larger than that of the gas phase, and the boiling heat transfer is larger than the natural convection and forced convection of the liquid phase. Thus, heat can be transferred very efficiently in the direct evaporative cooling (boiling heat transfer) system.

When the liquid phase and the gas phase of one substance are in thermal equilibrium and coexist, the temperatures of the two phases can be kept constant near the boiling point.

The present inventors have paid attention to the point that the heat transfer amount can be increased in the direct evaporative cooling system and that the constant temperature can be accurately maintained near the boiling point.

That is, in order to solve the above-mentioned problems, a plasma processing apparatus (1) according to the present invention includes a reaction vessel for processing a sample therein, and a plasma processing apparatus (1) provided inside at least a part of a peripheral wall of the reaction vessel. A constant temperature medium chamber, a liquefaction chamber communicating with the constant temperature medium chamber, heating means for heating the medium sealed in the constant temperature medium chamber, and cooling for liquefying the vaporized medium in the constant temperature medium chamber. Means.

As a material for the peripheral wall of the reaction vessel, it is necessary to use a plasma-resistant material having good thermal conductivity.

The constant temperature medium chamber may be of a closed chamber type capable of withstanding atmospheric pressure or higher, or may be provided with an expansion chamber 11i in a liquefaction chamber 11e formed in the peripheral wall of the reaction vessel 16 as shown in FIG. May be connected so that the pressure of the constant temperature medium chamber 11a can be controlled.

As the medium, it is necessary to select a medium which does not easily react with the material of the peripheral wall of the reaction vessel and has a boiling point near an optimum temperature for the target plasma treatment. And the like.

A heater is an example of the heating means. This heater is preferably disposed at a position soaked in a constant temperature medium in the constant temperature medium chamber.

A cooling pipe is an example of the cooling means.

Further, a plasma processing apparatus (2) according to the present invention.
Is a reaction vessel for processing a sample therein, a component disposed in the reaction vessel, a constant temperature medium chamber provided in at least a part of the component, and a constant temperature medium chamber. It is characterized by comprising a communicating liquefaction chamber, heating means for heating the medium sealed in the constant temperature medium chamber, and cooling means for liquefying the medium vaporized in the constant temperature medium chamber.

The constituent members include members other than the sample which is exposed to the plasma in the reaction vessel, that is, a metal or insulating material deposition plate, a target (metal or insulating material) used in a plasma sputtering apparatus or the like. Irrespective of the product) or an electrode in a parallel plate type plasma processing apparatus.

It is necessary to use a plasma-resistant material having good thermal conductivity as the material of the constituent members.

Further, in the plasma processing method according to the present invention, using the above-described plasma processing apparatus (1) or (2), the medium sealed in the constant temperature medium chamber is heated to a temperature near the boiling point of the medium using the heating means. The method is characterized in that the sample is processed by generating plasma in the reaction vessel while heating and cooling and liquefying the medium vaporized in the constant temperature medium chamber using the cooling means.

[0025]

According to the plasma processing apparatus (1) having the above structure,
A medium having a boiling point near the desired processing temperature is sealed in the constant temperature medium chamber, and the medium is heated to near the boiling point of the medium by the heating means in advance, so that the peripheral wall receives plasma irradiation during plasma processing. When heated, a large amount of heat is taken from the surrounding wall by the latent heat of evaporation of the direct evaporation method. On the other hand, the medium boils and vaporizes, and the vaporized medium is liquefied using the cooling means, and the temperature of the medium is maintained at a constant temperature near the boiling point. As a result, the peripheral wall becomes a desired temperature suitable for the processing in a short time and becomes stable at the desired temperature even if the number of times of the processing is repeated, so that the plasma processing speed is kept constant.

Further, according to the plasma processing apparatus (2) having the above configuration, the constituent members are maintained at a constant temperature by receiving substantially the same action as the peripheral wall of the reaction vessel in the plasma processing apparatus (1).

Further, according to the plasma processing method having the above-described structure, by using a medium having a boiling point near a desired processing temperature as the medium, the peripheral wall or the constituent member is heated by receiving plasma irradiation during the plasma processing. Even
A large amount of heat is taken from the peripheral wall or the constituent members by the latent heat of evaporation of the direct evaporation method. The medium boils and vaporizes, and is cooled and liquefied by the cooling means,
The temperature of the medium is kept constant near the boiling point. As a result, the peripheral wall or the constituent members are set to a desired temperature suitable for processing in a short time, and are stabilized at the desired temperature even if the number of times of processing is repeated, and the plasma processing speed is maintained constant.

[0028]

Examples and Comparative Examples Hereinafter, examples and comparative examples of a plasma processing apparatus according to the present invention and a plasma processing method using the apparatus will be described with reference to the drawings.

[Embodiment 1] FIG. 3 shows an EC according to Embodiment 1.
FIG. 2 is a schematic sectional view of a plasma processing apparatus using R,
In the figure, reference numeral 10 denotes a plasma processing apparatus, and reference numeral 16 denotes a reaction vessel. The reaction vessel 16 constitutes a plasma generation chamber 11 and a sample chamber 13, and a peripheral wall 11w of the plasma generation chamber 11 has a double structure so that a medium in a liquid state leaves a gas layer therein. Enclosed, the liquid layer accommodating portion of the medium is a constant temperature medium chamber 11a, and the gas layer accommodating portion of the medium is a liquefaction chamber 11e. A heater 11f is provided below the constant temperature medium chamber 11a so as to be immersed in the medium, and the medium is heated by the heater 11f. Further, a cooling pipe 11 through which cooling water set at a predetermined temperature of, for example, 20 ° C. flows through the liquefaction chamber 11e.
h is disposed, and the vaporized medium is liquefied by the cooling pipe 11h. Further, a bellows type expansion chamber 11i is connected to the liquefaction chamber 11e via a pipe 11j, and the expansion chamber 11i mitigates a pressure rise due to evaporation and vaporization of the medium, and the constant temperature medium chamber 11a and the liquefaction chamber 11e. Pressure is adjusted.

A microwave inlet 11c sealed with a quartz glass plate 11b is formed at the center of the upper wall of the plasma generation chamber 11, and a plasma extraction window is provided at a position facing the microwave inlet 11c at the center of the lower wall. 11
d is formed. A waveguide 1 having the other end connected to a microwave oscillator (not shown) at a microwave inlet 11c.
2 is connected to one end, and a sample chamber 13 is provided facing the plasma extraction window 11d. Further, an excitation coil 14 is disposed concentrically with the plasma generation chamber 11 and the waveguide 12 connected thereto so as to surround them over one end thereof.

On the other hand, a sample table 15 for mounting the sample S is provided in the sample chamber 13 at a position facing the plasma extraction window 11d, and a lower wall of the sample chamber 13 is connected to an exhaust device (not shown). Exhaust port 13a is formed.
In the figure, 11 g indicates a gas supply system connected to the plasma generation chamber 11, and 13 g indicates a gas supply system connected to the sample chamber 13.

As the medium, it is necessary to use a medium having a boiling point near the temperature suitable for plasma treatment. In this case, the medium is inert, does not react with metals, has no electric conductivity, and is nonflammable and does not deteriorate. Table 1 is a fluorine-based inert liquid fluorinate (trade name of 3M, an organic compound having only a CF structure) having excellent properties.
Was used and the boiling point was 215 ° C.

[0033]

[Table 1]

The plasma processing apparatus 1 configured as described above
In the case of performing plasma processing on the surface of the sample S using 0, the medium in the constant temperature medium chamber 11a is first heated to a temperature slightly lower than the boiling point of the medium, for example, about 210 ° C., using the heater 11f. The temperature of the wall 11w is set near a temperature suitable for plasma processing. In addition, water of about 20 ° C. is passed through the cooling pipe 11h. Thereafter, the insides of the plasma generation chamber 11 and the sample chamber 13 are set to a predetermined degree of vacuum,
Gas supply system 11 in plasma generation chamber 11 or sample chamber 13
g or a gas supply system 13g to supply a gas so as to obtain a required gas pressure, and generate a magnetic field required for electron cyclotron resonance excitation by the excitation coil 14 while the microwaves enter the plasma generation chamber 11 through the microwave introduction port 11c. Is introduced and the gas is resonantly excited using the plasma generation chamber 11 as a cavity resonator to generate plasma. The generated plasma is applied to the sample chamber 1 formed by the exciting coil 14.
The diverging magnetic field whose magnetic flux density decreases toward the third side is projected onto the sample S and around the sample S in the sample chamber 13, and the surface of the sample S is subjected to plasma processing.

FIG. 4 shows a plasma processing apparatus 1 according to the first embodiment.
7 is a graph showing a result of performing an etching process on a silicon oxide film formed on the surface of a sample S and examining a change over time in an etching rate of the silicon oxide film by the above-described method using 0. 4, a plasma processing method described in JP-A-4-256316 was conducted as a comparative example in which the temperature of the plasma generation chamber was controlled with flowing water at about 80 ° C. as a comparative example. The results obtained by subjecting the formed silicon oxide film to an etching treatment and examining the change over time in the etching rate are shown.

The etching conditions were such that the microwave power was 1.5 kW, the pressure in the sample chamber 13 was 5 mTorr, and the flow rate of the etching gas (mixed gas of CF ₄ and CHF ₃ ) was 50 sccm. The vertical axis in the graph indicates the relative etching rate when the etching rate of the silicon oxide film for the first processed sample S is 1.0.

As apparent from FIG. 4, when the etching method using the plasma processing apparatus 10 according to the embodiment is used, the relative etching rate of the silicon oxide film is almost 1.0, ie, about 1.0, until the number of processed silicon oxide films reaches 40. There was no change, and there was almost no change over time in the etching rate. On the other hand, in the case of the etching method according to the comparative example, the number of processed wafers gradually decreases until the tenth wafer, and becomes as low as about 0.8 after the tenth wafer. Changes with time.
As described above, the medium enclosed in the constant temperature medium chamber 11a is preliminarily heated and the medium vaporized in the constant temperature medium chamber 11a is liquefied, so that the peripheral wall 11 of the plasma generation chamber 11 is liquefied.
The temperature of w was adjusted to be constant near a temperature suitable for the plasma processing, and the amount of C adhering to the sample S was reduced, so that the plasma processing speed could be maintained at a constant rate.

Next, the silicon oxide film having the resist pattern formed on the surface of the sample S is etched under the same etching conditions as in FIG. 4, and this process is performed on 40 samples S. Over time, the selectivity to resist (etching rate of silicon oxide film / etching rate of resist film) was examined. The results are shown in FIG. Here, the vertical axis indicates the relative selectivity when the resist selectivity for the first processed number of samples S is 1.0.

As is clear from FIG. 5, in the embodiment, the relative selection ratio hardly changed to about 1.0 until the number of processed sheets was 40, and the resist selection ratio hardly changed with time. However, in the conventional example, the relative selection ratio gradually increases as the number of processed sheets increases and reaches a large value of about 1.8 at the tenth sheet, and thereafter gradually increases. doing. As described above, by preheating the medium sealed in the constant temperature medium chamber 11a and liquefying the vaporized medium in the constant temperature medium chamber 11a,
By reducing the amount of C attached to the sample S, the resist-to-resist selectivity of the sample S could be kept almost constant.

FIG. 6 is a graph showing the results obtained by subjecting 80 samples S to the same etching treatment as in FIG. 4 and examining the change over time in the number of particles.

As is apparent from FIG. 6, in the example, the number of particles was maintained at a small value, and the number of particles hardly changed with time. On the other hand, in the conventional example, the number of particles increases gradually until the number of processed particles reaches the 20th, increases rapidly to about 100 at the 25th, and thereafter increases substantially to about 40, and further increases to about 40. Even after the sudden increase to about 180 on the first sheet, the value is considerably large, and the number of particles changes with time.
Such a change is caused by the temperature change of the surrounding wall 11w that occurs with the on-off of the plasma and the surrounding wall 11w.
It is considered that the reaction products attached to w easily peel off, and that when the film thickness of the reaction products exceeds a certain level, a large amount of the reaction products peels off due to its own weight and the number of particles increases suddenly. Can be As described above, by preheating the medium sealed in the constant temperature medium chamber 11a and liquefying the vaporized medium in the constant temperature medium chamber 11a,
The temperature of the peripheral wall 11w is adjusted to be constant irrespective of the on-off state of the plasma to prevent the reaction products from being separated due to the temperature change of the peripheral wall 11w, and to prevent the number of particles from increasing due to an increase in the number of processed substrates. Was completed.

As described above, in the plasma processing method using the plasma processing apparatus 10 according to the first embodiment,
By using a medium having a boiling point near the temperature suitable for the plasma processing, even if the peripheral wall 11w is heated by receiving plasma irradiation during the plasma processing, a large amount of heat is generated from the peripheral wall 11w by the evaporation latent heat of the direct evaporation method. Be deprived. The medium boils and evaporates, and is cooled and liquefied by the cooling water flowing through the cooling pipe 11h, so that the temperature of the medium is maintained at a constant temperature near the boiling point. As a result, the temperature of the peripheral wall 11w can be set to a temperature suitable for plasma processing in a short time, and the temperature of the peripheral wall 11w can be stably maintained at a desired temperature even if the number of times of processing is increased. The etching rate and the selectivity can be kept constant by reducing the amount of deposition of the decomposition products of the etching gas.

Further, since the temperature of the peripheral wall 11w of the plasma generation chamber 11 is kept constant irrespective of the on-off state of the plasma, separation of the reaction product due to a change in the temperature of the peripheral wall 11w is prevented, and particles are not generated. Generation can be prevented.

In this embodiment, the case where a part of the peripheral wall of the reaction vessel 16, that is, the peripheral wall 11w of the plasma generation chamber 11 has a double structure has been described as an example. The entire peripheral wall of the container 16 may have a double structure.

In this embodiment, the case where the constant temperature medium chamber 11a and the liquefaction chamber 11e are integrally formed has been described as an example. However, in another embodiment, the constant temperature medium chamber 11a and the liquefaction chamber 11e are formed integrally. It may be formed separately and communicated.

Further, in this embodiment, the case where Fluorinert FC-70 (trade name of 3M Co., USA) is used as the medium has been described as an example. In addition, various florinates (trade name of US 3M) FC-7 shown in Table 1
_{2 (C 6 F 14),} FC-84 (C 7 F 16), FC-7
_{7, FC-75 (C 8} H 18), FC-40, FC-4
3, FC-71, water, perchlorethylene (CCl ₂ =
CCl ₂ ), trichloroethylene (CHCl = CCl
₂ ), 1.1.1-Various media such as trichloroethane (CCl ₃ CH ₃ ) which hardly reacts with the constituent material of the peripheral wall 11 w of the plasma generation chamber 11 can be used. What is necessary is just to select and use the medium which has.

In this embodiment, the case where the heater 11f is provided as the medium heating means has been described as an example. However, in another embodiment, another infrared lamp or the like is provided as the heating means. You may.

Further, in this embodiment, the case where the cooling pipe 11h is provided as a cooling means for the vaporized medium has been described as an example. However, in another embodiment, other cooling shrouds or the like are provided as the cooling means. It may be provided.

In this embodiment, the plasma processing apparatus 10
Is a plasma processing apparatus using ECR, but in another embodiment, a plasma processing apparatus using a magnetic field microwave that does not use ECR may be used.

[Embodiment 2] FIG. 7 is a sectional view schematically showing a parallel plate type bias sputtering apparatus according to a second embodiment.
Reference numeral 6 denotes a reaction vessel. A target electrode 21 is provided on the upper portion of the reaction vessel 26. The target electrode 21 has a double structure, in which a medium in a liquid state is sealed so as to leave a gas layer, and a liquid layer is sealed. The accommodation part is a constant temperature medium chamber 21a, and the gas layer accommodation part of the medium is a liquefaction chamber 21e. Constant temperature medium room 2
A heater 21f is provided under the medium 1a so as to be immersed in the medium, and the medium is heated by the heater 21f. In the liquefaction chamber 21e, for example, a cooling pipe 21h through which cooling water set at a predetermined temperature flows is disposed, and the vaporized medium is liquefied by the cooling pipe 21h. Further, a bellows type expansion chamber 21i is connected to the liquefaction chamber 21e through a pipe 21j, and the expansion chamber 21i reduces a rise in pressure due to the evaporation of the medium, and the constant temperature medium chamber 21a and the liquefaction chamber 21e.
Pressure is adjusted. The target 25 is held on the lower surface of the target electrode 21.

A heater 24 is provided below the reaction vessel 26.
A sample stage electrode 24 in which a is provided is provided, and a sample S is mounted on the sample stage electrode 24. A gas supply system 23 g is provided on the side wall of the reaction vessel 26.
High frequency power supplies 22b and 24b are connected to the target electrode 21 and the sample stage electrode 24, respectively.

When an Al film is formed on the surface of the sample S using the parallel plate type bias sputtering apparatus 20 having the above structure and Al as the target 25, first, FC-43 having a boiling point of 174 ° C. is used as a medium. After sealing in the chamber 21a, the sample S is placed on the sample stage electrode 24 in the reaction vessel 26.
Is placed. Next, the constant temperature medium chamber 2 is
The medium in 1a is heated to a temperature slightly lower than the boiling point of the medium, for example, about 170 ° C., and the lower portion of the target electrode 21 is kept close to a temperature suitable for plasma processing. In addition, water of about 20 ° C. is passed through the cooling pipe 21h. Thereafter, the inside of the reaction vessel 26 is set to a predetermined degree of vacuum, and Ar gas is supplied through the gas supply system 23g so as to obtain a required gas pressure. Next, by applying a high-frequency electric field from the high-frequency power supplies 22b and 24b to the target electrode 21 and the sample stage electrode 24, Ar gas is turned into plasma, and a target 25 mainly made of Al is sputtered by Ar ions, and the sample S
An Al film is formed on the surface.

In the processing method using the parallel plate type bias sputtering apparatus 20 according to the second embodiment, the medium according to the first embodiment shown in FIG. Processing device 10
, The target electrode 21 can be maintained at a constant temperature by the substantially same effect as the peripheral wall 11w of the plasma generation chamber 11, local erosion (erosion) of the target 25 can be prevented, and the sputtering rate can be kept constant.

[Embodiment 3] FIG. 8 is a cross-sectional view schematically showing a parallel plate type RIE apparatus 30 according to a third embodiment, and shows a parallel plate type bias sputtering apparatus 20 according to the second embodiment shown in FIG. The description of the portions having the same configuration as that described above will be omitted, and only the differences will be described. The same components as those in the second embodiment are denoted by the same reference numerals.

In the figure, reference numeral 30 denotes a parallel plate type RIE apparatus;
Indicates a reaction vessel. An earth electrode 27 is provided on the upper portion of the reaction vessel 26. The earth electrode 27 has a double structure, in which a liquid medium is sealed so as to leave a gas layer. The accommodation part is a constant temperature medium chamber 27a, and the gas layer accommodation part of the medium is a liquefaction chamber 27e. A heater 27f is provided below the constant temperature medium chamber 27a so as to be immersed in the medium, and the medium is heated by the heater 27f. The liquefaction chamber 27e is provided with a cooling pipe 27h through which, for example, cooling water set at a predetermined temperature flows, so that the vaporized medium is liquefied by the cooling pipe 27h. Further, a bellows type expansion chamber 27i is connected to the liquefaction chamber 27e via a pipe 27j, and the expansion chamber 27i alleviates a rise in pressure due to evaporation of the medium, and the constant temperature medium chamber 27a and the liquefaction chamber 27e. Pressure is adjusted.

A sample stage electrode 34 is provided below the reaction vessel 26, and the sample S is mounted on the sample stage electrode 34. A high-frequency power supply 34b is connected to the sample stage electrode 34.

The parallel plate type RIE apparatus 30 according to the third embodiment.
In the case of using a medium having a boiling point near the temperature suitable for plasma processing, the same effect as that of the target electrode 21 in the parallel plate bias sputtering apparatus 20 according to the second embodiment can be obtained when etching the surface of the sample S. Thereby, the earth electrode 27 can be maintained at a constant temperature.
Accordingly, the amount of the decomposition product of the etching gas adhered to the surface of the sample S can be reduced, and the etching rate can be kept constant.

By setting the temperature change range of the ground electrode 27 to less than 20 ° C., the reproducibility of the process can be improved.

[0059]

As described above in detail, in the plasma processing apparatus (1) according to the present invention, a reaction vessel for processing a sample therein and at least a part of a peripheral wall of the reaction vessel are provided. A constant temperature medium chamber provided therein, a liquefaction chamber communicating with the constant temperature medium chamber, a heating means for heating a medium sealed in the constant temperature medium chamber, and a liquid medium for vaporizing the medium vaporized in the constant temperature medium chamber. The cooling means, the medium having a boiling point near the desired processing temperature is sealed in the constant temperature medium chamber, and the medium is heated in advance to a temperature near the boiling point of the medium by the heating means. Even if is heated by receiving plasma irradiation during the plasma processing, the temperature of the medium is kept constant near the boiling point. As a result, the peripheral wall can be set to a desired temperature suitable for processing in a short time, can be stably maintained at the desired temperature even if the number of times of processing is repeated, and the plasma processing speed can be maintained constant.

The plasma processing apparatus (2) according to the present invention
Wherein a reaction container for processing a sample therein, a component disposed in the reaction container, a constant temperature medium chamber provided in at least a part of the component, A liquefaction chamber communicating with the medium chamber, heating means for heating the medium sealed in the constant temperature medium chamber, and cooling means for liquefying the medium vaporized in the constant temperature medium chamber; The constituent members can be maintained at a constant temperature by an effect substantially similar to that of the peripheral wall of the reaction vessel in the plasma processing apparatus (1).

Therefore, when the constituent member is the ground electrode of the parallel plate type RIE apparatus, the etching rate can be kept constant, and the temperature change range of the lower surface of the ground electrode becomes less than 20 ° C. Reproducibility can be improved.

Further, in the plasma processing method using the plasma processing apparatus (1) or (2) according to the present invention, the medium sealed in the constant temperature medium chamber is heated to a temperature near the boiling point of the medium by using the heating means. While heating,
The medium vaporized in the constant temperature medium chamber is cooled and liquefied using the cooling means, and the sample is processed by generating plasma in the reaction vessel, so that the temperature of the medium is kept constant near the boiling point, The peripheral wall or the constituent members can be set at a desired temperature suitable for processing in a short time, can be stably maintained at a desired temperature even if the number of times of processing is repeated, and the plasma processing speed can be maintained constant. .

[Brief description of the drawings]

FIG. 1 is a graph showing heat transfer coefficients of various refrigerants (heating media).

FIG. 2 is a schematic sectional view for explaining an arrangement position of an expansion chamber.

FIG. 3 is a sectional view schematically showing a first embodiment of the plasma processing apparatus according to the present invention.

FIG. 4 is a graph showing a change over time of an etching rate when the apparatus according to the first embodiment and the apparatus according to the related art are used.

FIG. 5 is a graph showing a change over time in a relative selectivity (to resist) when the apparatus according to the first embodiment and the apparatus according to the related art are used.

FIG. 6 is a graph showing the change over time in the number of particles when the device according to the first embodiment and the device according to the conventional example are used.

FIG. 7 is a sectional view schematically showing a parallel plate type bias sputtering apparatus according to a second embodiment.

FIG. 8 is a cross-sectional view schematically illustrating a parallel plate RIE apparatus according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plasma processing apparatus 11 Plasma generation chamber 11a, 21a, 27a Constant temperature medium chamber 11e, 21e, 27e Liquefaction chamber 11f, 21f, 27f Heater 11h, 21h, 27h Cooling pipe 11w Peripheral wall 20 Parallel plate type bias sputtering apparatus 21 Target electrode 27 Earth electrode 30 Parallel plate type RIE device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/205 H01L 21/205 21/3065 21/302 B

Claims (3)

(57) [Claims] A reaction vessel for processing a sample therein; a constant temperature medium chamber provided at least in a part of a peripheral wall of the reaction vessel; a liquefaction chamber communicating with the constant temperature medium chamber; A plasma processing apparatus, comprising: heating means for heating a medium sealed in a constant temperature medium chamber; and cooling means for liquefying a medium vaporized in the constant temperature medium chamber. 2. A reaction container for processing a sample therein, a constituent member disposed in the reaction container, a constant temperature medium chamber provided in at least a part of the constituent member,
A liquefaction chamber communicating with the constant temperature medium chamber, heating means for heating the medium sealed in the constant temperature medium chamber, and cooling means for liquefying the medium vaporized in the constant temperature medium chamber A plasma processing apparatus characterized by the above-mentioned. 3. The medium sealed in the constant temperature medium chamber is heated to a temperature near the boiling point of the medium using the heating means, and the medium vaporized in the constant temperature medium chamber is cooled using the cooling means. The plasma processing method using the plasma processing apparatus according to claim 1, wherein the sample is processed by generating plasma in the reaction vessel while liquefying.