JP2002252215A - Plasma processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve capability of controlling temperature. SOLUTION: In the plasma processing equipment, a holding member 5 for an object to be processed and a wall 30 made of insulator or semiconductor face each other, sandwiching a plasma processing space 3a in a vacuum chamber 3. The plasma processing equipment comprises: first temperature control means 5d, 5g capable of controlling the temperature of the holding member 5; a heat conducting member 40 attached to the wall 40 via a gap filler 73 from the opposite side of the plasma processing space 3a; and second temperature control means 71, 72 capable of controlling the temperature of the heat conducting member 40. Thus, temperature control capability is easily improved.

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 a plasma etcher, a plasma CVD, and a plasma asher, and more particularly to a plasma processing apparatus suitable for performing a plasma processing in a high-precision manufacturing process such as an IC or an LCD. Related to the device.

[0002]

2. Description of the Related Art In each of two basic plasma processing apparatuses shown in FIG. 8, a holder for a workpiece and a dielectric wall are opposed to each other with a plasma processing space interposed in a vacuum chamber.
The plasma excitation energy is supplied from the outside to the inside plasma processing space through the wall. For this purpose, a vacuum chamber in which a chamber upper lid 1 that can be opened and closed with respect to the chamber main body 3 in which a plasma processing space 3a is formed is provided, and the vacuum chamber is provided on the inner bottom of the chamber main body 3 and supported by a support 5a or the like. A holding part 5 for holding a processing object 4 to be processed, and a plasma which is usually mounted on the chamber top lid 1 so as to be located between the chamber top lid 1 and the chamber main body 3 and is provided with the chamber top lid 1 closed It has an opposing wall 2 made of an insulator that opposes the object holding surface of the holder 5 with the processing space 3a interposed therebetween.

[0003] The holding portion 5 has a holding surface, such as an upper surface, which is suitable for the object to be processed 4 and is flattened, for example, in order to hold the object to be processed 4 mounted and / or biased. If so, an electrostatic chuck or the like is also provided there. An exhaust port 3b is formed at an appropriate position on the bottom wall or side wall of the chamber main body 3 to evacuate the plasma processing space 3a in the vacuum chamber, and a variable valve 6a and a vacuum pump 6 Are linked. Further, an RF cable 9a for introducing a high frequency for plasma excitation from the RF power source 8
Further, a gas pipe for supplying a gas for plasma processing from a gas supply unit (not shown), an opening / closing gate (not shown) for carrying in / out the workpiece 4 and the like are also provided.
Then, under the control of a controller (not shown) composed of an electronic circuit such as a microprocessor system, vacuum pressure control, gas flow rate control, and the like suitable for forming the plasma 7 are performed in accordance with a so-called recipe that defines the procedure and contents of the plasma processing. It is performed automatically.

[0004] Of these two examples, the one shown in FIG. 8 (a) is a basic device of the capacitive coupling type. In this case, the upper surface of the opposing wall 2, that is, the back surface of the opposing wall 2 which is not opposed to the holding portion 5. , A conductive plate 9z is spread, and an RF cable 9a is connected to the conductive plate 9z. In contrast, FIG.
(B) is a basic device of the inductive coupling system. In this case, a coil 9 is routed on the upper surface of the opposing wall 2 and an RF cable 9a is connected thereto.

Further, the plasma processing apparatus shown in FIG.
As disclosed in Japanese Patent Application Laid-Open No. 10-294307, the plasma generation space 21 and the plasma processing space 3a are disclosed.
Are separated from each other in an adjacent state, and the plasma generation space 21 is formed on the opposing wall 20 by engraving or the like and is dispersed. On the upper surface side and the rear surface side of the opposing wall 20, in addition to the coil 9, a magnet 22 for sealing electrons is provided, and a plasma gas supply path 23 is also formed. A conductive plate 10 on which a processing gas supply port 11 and a plasma jet port 12 are formed is provided on the lower surface side and the opposite surface side of the opposing wall 20. Then, the plasma 7 is generated in the plasma generation space 21 and sent to the plasma processing space 3a from many small plasma jet ports 12.

Further, any of the plasma processing apparatuses (FIG. 8)
(A), FIG. 8 (b), and FIG. 9), in order to release heat from the holding unit 5 and to make it possible to adjust the temperature, the holding unit 5 is provided with heat radiating means (first temperature adjusting means and first temperature adjusting means). Adjustment device)
Is added. Specifically, a liquid flow path 5g for circulating the cooling liquid is formed inside the holding unit 5, a cooling device 53 for supplying the cooling liquid is installed outside the vacuum chamber, and both are connected to the pipe 5d. So that the coolant can flow back and forth between them. When etching is performed, heat is generally radiated in such a manner. On the other hand, when film formation (CVD) is performed, the temperature is often adjusted using a heating device.

[0007]

As described above, in the conventional plasma processing apparatus, the temperature of the holding section for holding the object to be processed is adjusted, so that a large change in temperature or disturbance of the temperature distribution is caused. In the plasma treatment to prevent the fineness and precision of the plasma processing from being impaired.
However, since the object to be processed is carried in and out and cannot be fixed to the holding unit, and the plasma processing is performed in a vacuum atmosphere, the temperature of the object is directly adjusted. However, since the temperature of the object to be processed is indirectly adjusted by directly controlling the temperature of the holding unit, the ability to adjust the temperature of the object to be processed is limited.

[0008] By the way, demands for finer processing and higher precision in plasma processing are becoming stricter, and there is also a demand for power-up for improving processing efficiency and expanding a variable range of plasma density. In order to meet these demands, it is important to increase the temperature control ability for the object to be processed. Therefore, under the constraint that the temperature of the object to be processed cannot be directly controlled, the technical issue is how to modify the device structure etc. in order to increase the temperature control capability for the object to be processed. Becomes The present invention has been made to solve such a problem, and has as its object to realize a plasma processing apparatus having a high temperature control ability.

[0009]

Means for Solving the Problems First to third solving means invented to solve such problems are as follows.
The configuration and operation and effect will be described below.

[First Solution] According to a first aspect of the present invention, there is provided a plasma processing apparatus, comprising: a vacuum chamber having a plasma processing space formed therein; A holding portion that is provided or formed and holds an object to be processed, and an insulator or semiconductor wall that is provided in addition to or incorporated in the vacuum chamber and faces the holding portion across the plasma processing space. In the plasma processing apparatus provided with, the first temperature control means for performing one or both of the heat radiation from the holding portion and the heating thereof to control the temperature, and the opposite of the plasma processing space with respect to the wall A heat transfer member attached in a deployed state from the side, that is, the front surface and the back surface of the wall, which are not in contact with the plasma processing space, with a gap filling material interposed therebetween over the entire surface or a part thereof Has a second temperature adjusting means for enabling the temperature controller performs either or both of the heat radiation and heat thereto from the heat transfer member, is that.

Here, the term "opposite" means that the vacuum chamber should oppose when establishing a vacuum atmosphere necessary for plasma formation, and when the plasma processing is not performed, for example, at the time of maintenance work or an object to be processed. At the time of loading and unloading, it may or may not face each other.

In the plasma processing apparatus of the first solution, the temperature of the heat transfer member is directly adjusted by the second temperature adjusting means, and the temperature of the heat transfer member is spread on the wall with a gap filler therebetween. Because of the wearing, the heat transfer is performed well over a wide range, so that the temperature of the wall is appropriately adjusted. Accordingly, radiant heat from the wall to the object to be treated, etc., does not fluctuate significantly and becomes stable. Its distribution is also more uniform. Accordingly, the temperature of the holding portion is adjusted by the first temperature adjusting means, and the temperature of the object to be processed is indirectly adjusted from the holding portion side, and the temperature of the heat transfer member is adjusted by the second temperature adjusting means. Since the temperature of the object to be processed is also indirectly controlled from the wall side, the temperature control ability is improved even with only indirect means.

In addition, even if such a second temperature control means is added, it is not directly added to the wall but is added to the heat transfer member and combined, so that the second temperature control means is in direct contact with the plasma processing space. Walls having few degrees of freedom such as materials and shapes and generally having many restrictions on design and processing do not have to be complicated, so that manufacturing is easy and cost increase is suppressed. Therefore, according to the present invention, it is possible to easily and easily realize a plasma processing apparatus having a high temperature control ability.

[Second Solution] The plasma processing apparatus according to the second solution is the plasma processing apparatus according to the first solution, wherein the heat transfer is performed by the plasma processing apparatus. The member is composed of a plurality of members, which are stacked, and a gap filler is interposed between them.

In the plasma processing apparatus according to the second aspect, since the heat transfer member is divided into a plurality of parts, the degree of freedom in designing the member selection, the shape, and the like is increased, and the processing means and the assembling procedure are improved. The range of choices also expands. Moreover, since the gap filler is interposed between the heat transfer members even when the heat transfer members are divided in this manner, a decrease in the heat transfer capability is avoided or sufficiently reduced. Therefore, according to the present invention, it is possible to realize a plasma processing apparatus having a high temperature control ability and easy to manufacture.

[Third Solution] A plasma processing apparatus according to a third solution is the plasma processing apparatus according to the second solution, wherein the plurality of plasma processing apparatuses are different from each other. Among the heat transfer members, the one closer to the wall has a coefficient of thermal expansion closer to the coefficient of thermal expansion of the wall than the one farther from the wall, and the one of the plurality of heat transfer members farther from the wall is closer to the wall. It has higher thermal conductivity than the closer one.

In the plasma processing apparatus of the third solution, the temperature becomes uniform over a wide range due to the presence of the heat transfer member having high thermal conductivity, and the thermal expansion coefficient is close to the wall. Since the heat transfer member is arranged and the difference between the deformation amount of the heat transfer member and the deformation amount of the wall with respect to the temperature change is small, the uniformity of the temperature distribution can be achieved without giving undesired thermal distortion to the wall. Can be increased. Therefore, according to the present invention, it is possible to realize a plasma processing apparatus having a higher temperature control ability and easier to manufacture.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments for implementing the plasma processing apparatus of the present invention achieved by the above-described solution will be described. These embodiments have been devised in view of the fact that each of the conventional plasma processing apparatuses described above has advantages and disadvantages in terms of generation and supply of plasma.

That is, the capacitive coupling type apparatus shown in FIG. 8A has an advantage that a uniform plasma can be easily obtained over a wide range, but has a disadvantage that it is difficult to increase the plasma density due to a limitation in energy input. In addition, the inductive coupling type apparatus shown in FIG. 8B has an advantage that the plasma density is increased by increasing the high-frequency power, while the disadvantage is that the uniformity of the plasma is impaired when the energy input is increased. is there. In contrast, the separation / dispersion type apparatus shown in FIG. 9 does not have these disadvantages and has both advantages. Specifically, not only can the plasma density be variably controlled over a wide range from low density to high density, but even in this case, the uniformity of the plasma is ensured.

However, the separation-dispersion type apparatus also has an unsolved problem that it is difficult to improve the energy use efficiency. That is, since the generated plasma is not immediately subjected to the plasma processing, a relatively large proportion of the high-density plasma is consumed on the wall of the plasma generation space or the like. In order to achieve this, a high-output power supply had to be used for the high-frequency power supply. Therefore, it is important to make further efforts so that high-density plasma can be supplied without impairing the uniformity of the plasma and energy efficiency is improved.

The plasma processing apparatus according to the first embodiment of the present invention is the plasma processing apparatus according to the above-described means, wherein the wall is directly opposed to the holding portion, and the opposite surface is provided. And a coil to which high frequency can be applied is housed in the protrusion. That is, apart from the plasma processing space and the gas such as plasma in the plasma processing space and the workpiece to be dynamically carried in for the plasma processing, the wall is directly connected to the holding portion without any other solids. At least a portion of the wall facing the holding portion is formed with a projection protruding into the plasma processing space in a dispersed manner or the like, and the projection has a high frequency generated by a first high frequency power supply. That is, a coil that can be applied is contained.

Here, the above-mentioned "dispersion etc." means not only literal dispersal of being scattered in a point-like manner, but also cases of being divided so as not to be close to each other,
When a plurality of or a mixture of them are distributed in a line, a broken line, a straight line, a curved line, etc.
Polygonal and spiral shapes are concentric or non-concentric, and a large number of them are arranged side by side or formed widely alone. However, since they protrude to the last, the total area of the protruding portions does not exceed the total area of the base portions and the basal surfaces that do not protrude.

In the plasma processing apparatus of such an embodiment, the high frequency applied to the coil is radiated to the plasma processing space or the like through the protruding portion of the wall. Since it is provided as if it were inserted into the space, high-frequency radiant energy is injected into the plasma processing space at a high rate. In general, even if only the protrusions are locally thinned, the strength and rigidity of the entire wall are not largely lost and can be easily reinforced with a backing or the like. Energy efficiency can be improved.

Thus, high-density plasma can be efficiently formed in the plasma processing space. Even in such a case, since the coil is arranged in a state of being dispersed and the like together with the projecting portion and facing the object to be processed, the distribution of energy input becomes uniform when designing the projecting portion and the like. Due to such considerations, the plasma density becomes sufficiently homogeneous over the entire range even if the surface of the object to be processed is wide. Therefore, according to this embodiment, it is possible to realize a plasma processing apparatus capable of efficiently supplying high-quality plasma and having a high temperature control ability.

A plasma processing apparatus according to a second embodiment is the plasma processing apparatus according to the above-described embodiment, wherein the heat transfer member is made of a conductor, and can apply a high frequency by a second high frequency power supply. It has become. Alternatively, the heat transfer member or the wall is made of a semiconductor, so that a high frequency can be applied by the second high frequency power supply.

In the plasma processing apparatus of such an embodiment, in addition to energy input by inductive coupling through a coil, energy input by capacitive coupling through a conductor or a wall can be used. In the capacitive coupling method, although the amount of energy input is limited, it is easy to obtain uniformity. By adding this, the plasma density can be further increased without impairing the uniformity. Therefore, according to this embodiment, it is possible to realize a plasma processing apparatus capable of efficiently supplying higher quality plasma and having a high temperature control ability.

The plasma processing apparatus according to the third embodiment is the same as the plasma processing apparatus according to the second embodiment, except that a gas flow path is dispersed in the conductor or at a junction between the conductor and the wall. And the gas flow path is incorporated in the middle of a gas supply path from outside the vacuum chamber to the plasma processing space.

In the plasma processing apparatus of such an embodiment, since the gas flow path is formed by utilizing the conductor provided on the wall, the gas flow path may be dispersed. In addition, the structure of the wall can be prevented from becoming complicated.
In addition, a wall made of an insulator or a semiconductor, which is often brittle, is difficult to perform complicated processing, whereas a conductor made of metal or the like is generally easy to be processed. Thus, even if the gas flow path is dispersed and the like, the complicated gas piping and processing are not required or reduced so that the supply of the processing gas toward the plasma density is performed in addition to the distribution of the plasma density. . Therefore, according to this embodiment, a plasma processing apparatus that can efficiently supply higher quality plasma and has high temperature control capability can be easily realized.

A fourth embodiment of the present invention is the plasma processing apparatus according to the above-described embodiment, wherein the holding section is capable of applying a high frequency by a third high-frequency power supply. Thereby, appropriate anisotropy can be given to the plasma processing.

A fifth embodiment of the present invention is the plasma processing apparatus according to the above-described embodiment, wherein the coil is divided into a plurality of parts and arranged concentrically, and the distribution of high frequency to them is varied. A variable distribution means is provided. This makes it possible to dynamically adjust the distribution state of the energy input, and to further improve the uniformity of the plasma density.

Specific embodiments for carrying out the plasma processing apparatus of the present invention achieved by the above-described means and embodiments will be described with reference to the following first to third embodiments. The first embodiment shown in FIGS. 1 to 5 embodies the above-described first solution and the first to fifth embodiments, and the second embodiment shown in FIG. The second and third solving means and the second embodiment described above are embodied, and the third embodiment shown in FIG. 7 is a modified example thereof. In the drawings, the same reference numerals are given to the same components as those in the related art, so that the overlapping description will be omitted, and the following description will focus on the differences from the related art.

[0032]

First Embodiment A first embodiment of the plasma processing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the entire structure, FIG. 2 is a longitudinal sectional view of a main part including a wall and a holding part, that is, a peripheral part of a plasma processing space, and FIG. FIG. 4 shows an example of the distribution varying means.

This plasma processing apparatus is different from the conventional apparatus in that the opposed wall 2 and the opposed wall 20 are replaced with the opposed wall 30.
Is installed, and a pipe 71 is connected to a cooling device 70 (second temperature control device) to enable temperature control by heat radiation.
A heat transfer member 40 connected so as to be able to receive a coolant through (second temperature control means) is also introduced. In addition to the coil 9, the heat transfer member 40 is made of a conductor to apply a high frequency. That the distribution variable means 9 is connected to the RF cable 9a.
0 is an interposed connection.

The opposing wall 30 is formed by milling or perforating an insulating plate such as alumina or aluminum nitride. The opposing wall 30 has a concentric circle on the surface facing the plasma processing space 3a, that is, the surface facing the holding portion 5. Several linear protrusions 31 arranged in a shape are formed. Further, a large number of small through holes 63 are formed so as to avoid the projecting portions 31, and the plasma processing gas supplied to the plasma processing space 3 a via the small through holes 63 and the plasma 7 generated by the excitation thereof are confined. The distance between the inner and outer protruding portions 31 is set to be sufficiently large so that the width is not larger than the width of the protruding portion 31.
Such an opposing wall 30 is different from the opposing wall 2 in that the opposing surface is uneven, and the opposing wall 30 in which the recessed-side plasma generation space 21 is dispersed and the like in that the protrusions 31 are dispersed and the like. It is different from the wall 20. The difference is that the conductive plate 10 is not attached to the facing surface and the facing surface directly faces the workpiece holding surface of the holding unit 5.

A groove 32 for accommodating the coil 9 is formed concentrically on the upper and lower surfaces of the opposing wall 30 so as to correspond to the protruding portion 31. The groove 32 is deeply carved into the protrusion 31 so that the coil 9 is accommodated inside the protrusion 31. Further, the wall thickness of the protruding portion 31 is made considerably thinner than the plate thickness of the opposing wall 30, so that the distance between the coil 9 and the plasma processing space 3a is shortened in each step as compared with the related art. In order to reinforce the strength and rigidity of the opposed wall 30 reduced by the formation of the groove 32, a padding may be inserted into the groove 32,
In this example, the heat transfer member 40 is fixed to the upper and lower surfaces of the opposing wall 30 in a developed state, so that the opposing wall 30 has sufficient strength and rigidity to withstand vacuum pressure.

At the time of the spreading, a gap filler 73 made of an adhesive or an elastic film is interposed between the opposing wall 30 and the heat transfer member 40, so that there is no or little gap with poor heat transfer. It has become something. As the gap filling material 73, an organic adhesive having excellent heat resistance and heat conductivity, a thin film of silicon rubber, or the like is suitable. Heat transfer member 40 and opposed wall 30
The fixation may be performed only by adhesion, only by fixed attachment using a fastening tool or a locking tool, or a combination thereof.

The heat transfer member 40 is made of a good conductor as in the case of the conventional conductive plate 9z, and an RF power source 42 (second high frequency power source) outside the vacuum chamber for enabling high frequency application.
An RF cable 41 extending from the terminal is connected. Also,
The heat transfer member 40 also differs from the conductive plate 9z in that a liquid flow path 72 (second temperature adjusting means) is formed inside. The liquid flow path 72 is formed so as to extend almost all over the heat transfer member 40, and a pipe 71 is connected to the liquid flow path 72,
The cooling liquid supplied from the cooling device 70 outside the vacuum chamber loops through the liquid flow path 72 and then returns. The cooling device 70 may be the same as or different from the conventional cooling device 53, and the pipe 71 may be the same as or different from the conventional pipe 5d.

Further, the heat transfer member 40 has a point where a gas pipe 61 extending from a gas supply unit 60 outside the vacuum chamber is connected to supply various plasma processing gases, and a gas flow path 62 is formed. That the conductive plate 9
different from z. The gas flow path 62 is formed by a groove that is easy to process. In order to allow the gas pipe 61 and the small through-hole 63 to communicate with each other in a state where the heat transfer member 40 is mounted on the opposing wall 30, the gas flow path 62 is formed in a concentric shape or a net shape. It is stretched. Such a gas flow path 62 is formed by dispersing or the like at a joint between the heat transfer member 40 made of a conductor and the opposed wall 30 made of an insulator, and serves as a gas supply path from outside the vacuum chamber to the plasma processing space 3a. It is built in the middle.

Each coil 9 is also made of a good conductor that can serve as an antenna, and an RF power supply 8 (first high-frequency power supply) and a matcher 8 outside the vacuum chamber to enable high-frequency application.
An RF cable 9a extending from a is connected, and a variable distribution means 90 is interposed where the RF cable 9a branches and reaches each coil 9. The distribution variable means 90 is provided in the same number as the coils 9 or one less. It is sufficient if the impedance can be changed according to the control of the controller. For example, a magnetic core 92 is put out (see FIG. 4A) into an air-core coil portion 91 connected in series in the middle of the RF cable 9a. 4
(Refer to (b)).

An RF cable 5b extending from an RF power supply 51 (third high-frequency power supply) outside the vacuum chamber is also connected to the holding unit 5 in order to apply a high frequency for giving anisotropy to the plasma processing. In order to function the electrostatic chuck 5f attached to the processing object holding surface, an electrostatic voltage applying cable 5c extending from the high voltage power supply 52 outside the vacuum chamber is connected, and the heat of the processing object 4 and the holding unit 5 is connected. A thin tube 5 extending from a gas supply unit 54 outside the vacuum chamber and supplying a heat transfer medium such as helium to improve the transfer.
e is connected. As in the conventional example, the holding section 5 also has a liquid flow path 5g formed therein and a pipe 5
d is connected and connected (first temperature control means), and the cooling liquid is supplied from the cooling device 53 (first temperature control device) outside the vacuum chamber to the liquid flow path 5g via the pipe 5d. ing.

The mode of use and operation of the plasma processing apparatus of the first embodiment will be described with reference to the drawings. FIG. 5 is a graph showing a change in the temperature of the opposing wall 30. The solid line graph is for the device of the present invention, while the broken line graph is for the conventional device shown for comparison. In addition, carry-in and carry-out of the workpiece 4 (see Japanese Patent Application Laid-Open No. 10-329061).
And chucking thereof (see JP-A-2000-3953, etc.), distribution of high-frequency power using the distribution variable means 90 (see JP-A-2000-58296, etc.), control of a plasma process according to a recipe, for example, vacuum The control of the pressure, the control of the gas supply, and the control of the applied voltage from the RF power supply 51 to the holding unit 5 (see Japanese Patent Application Laid-Open No. 10-294307) will not be described. However, the description will focus on the temperature control.

When a high frequency is applied from the RF power source 8 to the coil 9 via the RF cable 9a, an electromagnetic wave or the like is radiated from the coil 9 and the plasma 7 in the plasma processing space 3a is irradiated.
Since the inductive coupling between the gas and the coil 9 is established, electric power is supplied from the coil 9 to the plasma processing space 3a. At this time, the wall of the intervening protrusion 31 is thinner than before, and the plasma processing space 3a surrounding the protrusion 31 and the coil 9 also comes in three directions and occupies a wider angle than before. The input of the plasma excitation energy is performed more efficiently than before. Moreover, the protrusion 31 and the coil 9
Are concentrically divided and distributed, and the power distribution to each coil 9 is dynamically adjusted using the distribution varying means 90. Therefore, even if the plasma 7 has a high density, It is distributed uniformly over the entire upper surface of the object 4.

Also, the RF cable 41
When a high frequency is applied to the heat transfer member 40 via the heat transfer member 40, the heat transfer member 40 made of a conductive material and the plasma 7 in the plasma processing space 3a are applied.
Since the capacitive coupling is established between the gas and the gas and the displacement current flows through the opposing wall 30, electric power is also supplied from the heat transfer member 40 to the plasma processing space 3a. Since the heat transfer member 40 is widely spread on the upper surface of the opposing wall 30, power transmission by capacitive coupling does not impair the uniformity of the plasma density.
The density of the plasma 7 is further increased. Thus, in this plasma processing apparatus, in addition to energy input by efficient inductive coupling alone, energy input by capacitive coupling is also performed, so that plasma is generated and formed in the plasma processing space. Even with this, it is possible to supply plasma with higher density than before. In addition, uniformity of the plasma is ensured, so that high-quality plasma is efficiently supplied.

In addition, when such plasma processing is intermittently repeated, the temperature of the opposing wall 30 rises during processing and decreases at rest, and the temperature difference depends on the processing contents. In the case of etching a silicon wafer, there was conventionally about 100 ° C. (ΔT in FIG. 5).
1). On the other hand, in the plasma processing apparatus of the first embodiment, the heat of the opposing wall 30 is efficiently transmitted to the heat transfer member 40 through the gap filling material 73, and the heat transfer member 40 , The temperature change of the opposing wall 30 is considerably smaller than in the prior art, and falls within about 10 ° C. (see ΔT2 in FIG. 5). At the same time, the temperature of the holding unit 5 is adjusted in the same manner as in the related art.

In this way, if the energy input amount is the same, of course, even when the energy input amount is increased to supply high-density plasma, the temperature of the opposing wall 30 is more stable than before, and Since the temperature is also stable, the temperature of the processing object 4 is stable on both sides. As a result, even if the processing of the object to be processed is further miniaturized and highly accurate, appropriate plasma processing can be efficiently performed.

[0046]

SECOND EMBODIMENT FIG. 6 is a longitudinal sectional view of a main part including a wall and a heat transfer member, that is, a plasma processing apparatus of the present invention showing the vicinity of a second temperature control means is different from that of the first embodiment described above. This is because another heat transfer member 74 is interposed between the heat transfer member 40 and the opposing wall 30 and that the RF cable 41 is connected to the opposing wall 30 instead of the heat transfer member 40. It is. In FIG. 6, illustration of the RF cable 9a, the gas pipe 61, and the like is omitted.

Since application of a high frequency by the RF power supply 42 is performed on the opposing wall 30, the opposing wall 30 is made of a semiconductor such as silicon or SiC. The electric resistivity is desirably 2 Ωcm or more. Also, the heat transfer member 4
0 is made of a conductor such as a metal as described above,
The heat transfer member 74 is made of a semiconductor such as silicon or SiC similarly to the facing wall 30. Further, the opposing wall 30 and the heat transfer member 7
4, a gap filler 73 is interposed between the heat transfer member 40 and the heat transfer member 74.

In this case, the plurality of heat transfer members 40 and 74 are fixed in a state of being stacked on the opposing wall 30, and when the opposing wall 30 faces the holding portion 5, the heat transfer member 74 is The heat transfer member 40 is closer to the opposed wall 30 than the heat transfer member 40, and the heat transfer member 40 is farther from the opposed wall 30 than the heat transfer member 74.
Also, while the heat transfer member 74 and the opposing wall 30 having the same material have the same coefficient of thermal expansion, the heat transfer member 40 and the opposing wall 30 having different materials also have different coefficients of thermal expansion. It is customary. Further, in general, the heat transfer member 40 made of a conductor has higher thermal conductivity than the heat transfer member 74 made of an insulator.

When each member expands and contracts in response to a change in temperature, the amount of expansion and contraction differs between the opposite wall 30 and the heat transfer member 40 having different coefficients of thermal expansion. In the case of tying, it is necessary to design the opposed wall 30 and the heat transfer member 40 in consideration of the undesired bimetal-like thermal deformation. In addition, the heat transfer member 74 is
0 and the opposing wall 30, the expansion and contraction of the heat transfer member 40 has no effect on the deformation of the opposing wall 30, or is greatly reduced.

The heat of the facing wall 30 is transferred to the gap filler 73.
Is efficiently transmitted to the heat transfer member 74 through
The heat transfer member 4 is efficiently interposed via another gap filler 73.
Since it is transmitted to 0, the temperature change of the opposing wall 30 is considerably smaller than in the conventional case. Furthermore, RF power supply 4
2 is applied to the opposing wall 30 via the opposing wall 30 and capacitively engages the plasma 7 in the plasma processing space 3a via the opposing wall 30.
And transmitted to the gas.

Thus, in this case, as in the case of the above-described first embodiment, a plasma having a higher density than in the prior art can be supplied uniformly, and the temperature of the opposing wall is stable even in such a case. As a result, the processing of the object to be processed can be performed with higher definition. Moreover, in this case, when designing the heat transfer member 40, it is not necessary to deeply consider the influence of thermal deformation on the opposing wall 30. Therefore, the heat transfer member 40 is designed at the heat radiation center, and the heat transfer member 74 is Manufacturing is facilitated by designing mainly with respect to 30, heat transfer member 40, ease of assembly, and the like.

[0052]

Third Embodiment The plasma processing apparatus of the present invention, in which the opposing surface of the opposing wall 30 is shown in FIG. 7, is different from that of the first embodiment in that the projection 31 and the coil 9 are substantially rectangular. That is the point. While the above-mentioned round opposed wall 30 is suitable when the object 4 is a disc-shaped silicon wafer or the like, the square opposed wall 30 is suitable when the object 4 is a rectangular liquid crystal panel or the like. ing. In addition, as the size of the substrate is increased, the number of the protruding portions 31 and the coils 9 which are concentrically divided is increased from two to four, and the number of the small through holes 63 is also increased.

[0053]

[Others] In each of the above-described embodiments, a case where etching important for cooling is performed is described as an example.
The cooling unit 70 is used to cool the holding unit 5 and the cooling unit 70 to cool the opposing wall 30.
When performing D), it is preferable to adjust the temperature using a heating device. In this case, if a heating wire is embedded in the liquid flow paths 5g and 72, the temperature can be adjusted without flowing the liquid. Further, either one of the cooling and the heating may be performed, but the temperature may be adjusted by providing both the cooling unit and the heating unit and switching them appropriately. In addition, the method of adjusting the temperature may be a simple method in which heat radiation and heating are continuously performed, or may be an on-off control or a feedback control.

Further, the holding portion 5 and the opposing wall 30 may be a pair of parallel flat plates as described above when the object to be processed is a flat substrate, but when the object to be processed is not flat. Is appropriately modified based on its shape. For example, when the workpiece is curved, the workpiece holding surface of the holding unit 5 is finished to a curved surface corresponding to the back surface shape or the like. On the other hand, the facing wall 30 may be similarly curved, may have a gentler curved surface, or may be a flat plate, depending on the process conditions and the like.

When the opposing wall 30 and the heat transfer member 74 are made of a semiconductor, the heat transfer member 40 may not be a conductor, for example, the same as or similar in properties to the opposing wall 30 like the heat transfer member 74. A semiconductor may be used. In that case, the RF cable 41 may be connected to the facing wall 30 or the heat transfer member 74. Not only the protrusion 31 of the opposing wall 30 but also the heat transfer member 40 and the heat transfer member 74 may be dispersed linearly or the like, or may be divided concentrically or the like. The number of divisions is also arbitrary.

JP-A-10-29 instead of the variable valve 6a
The pressure control may be performed using a movable wall as disclosed in JP-A-4307 and JP-A-2000-58298. The diameter of the through hole 63 is usually 0.5 mm to 1 mm.
It is about mm, but is not limited to this, and is not limited to a drilled hole or a round hole.

[0057]

As is apparent from the above description, in the plasma processing apparatus according to the first solution of the present invention, the temperature of the object to be processed is indirectly controlled from both sides. Moreover, at that time, by combining a heat transfer member with a gap filling material interposed in the wall, a plasma processing apparatus having a high temperature control ability and easy to manufacture can be realized. Has an advantageous effect.

Further, in the plasma processing apparatus according to the second solution of the present invention, the heat transfer member is divided without deteriorating the heat transfer ability, so that the plasma processing apparatus has a high temperature control ability. This has the advantageous effect of being able to achieve easier manufacturing and the like.

Further, the plasma processing apparatus according to the third solution of the present invention is a plasma processing apparatus having a higher temperature control ability by superimposing different heat transfer members, and further manufacturing and the like. There is an advantageous effect that an easy one can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall structure of a first embodiment of a plasma processing apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part including a wall and a holding part.

FIG. 3 is a surface of the wall facing the holding unit.

FIG. 4 is an example of a distribution variable unit.

FIG. 5 is a graph showing a change in temperature of a wall.

FIG. 6 is a longitudinal sectional view of a main part including a wall and a heat transfer member in a second embodiment of the plasma processing apparatus of the present invention.

FIG. 7 is a surface of a wall of a third embodiment of the plasma processing apparatus according to the present invention, the surface facing a holding unit;

FIG. 8 shows an overall structure of a conventional plasma processing apparatus,
(A) is a basic capacitive coupling type, and (b) is a basic inductive coupling type.

9A and 9B show the structure of an existing apparatus obtained by improving a conventional plasma processing apparatus, wherein FIG. 9A is a longitudinal sectional view of a chamber portion, and FIG.
Is an enlarged view of a plasma generation space portion.

[Explanation of symbols]

Reference Signs List 1 chamber upper lid (vacuum chamber) 2 opposed wall (vacuum chamber) 3 chamber main body (vacuum chamber) 3a plasma processing space 3b exhaust port (suction port) 4 workpiece (substrate, silicon wafer, plastic film) 5 holder (vacuum) 5a Support 5b RF cable (means for applying high frequency to third high frequency power supply) 5c Cable (means for applying high voltage to electrostatic chuck) 5d Piping (supply path for coolant) Return path, first temperature control means 5e Narrow tube (heat transfer gas supply path / return path) 5f Electrostatic chuck (means for holding workpiece) 5g Liquid flow path (coolant circulating path, first temperature) Adjusting means) 6 Vacuum pump 6a Variable valve (variable throttle, pressure control mechanism, pressure control means) 7 Plasma 8 RF power supply (first high frequency power supply) 8a 9 coiler (antenna coil, inductive coupling means) 9a RF cable (high-frequency applying means to first high-frequency power supply) 9z conductive plate (capacitive coupling means) 10 conductive plate (partition between plasma processing space and plasma generation space) 11 Processing gas supply port 12 Plasma ejection port 20 Opposing wall (plasma generating mechanism, vacuum chamber) 21 Plasma generating space 22 Magnet (electronic sealing means) 23 Plasma gas supply path 30 Opposing wall (directly facing insulator or semiconductor) Wall of,
(Vacuum chamber) 31 Projection part 32 Groove (coil storage space) 40 Heat transfer member (in the case of a conductor, capacitive coupling means, far from a wall in a stacking member) 41 RF cable (means for applying high frequency to second high frequency power supply) 42 RF power supply (second high-frequency power supply) 51 RF power supply (third high-frequency power supply) 52 High-voltage power supply (power supply for electrostatic chuck) 53 Cooling device (chiller, liquid cooling device, first temperature control device) 54 Gas supply unit (heat transfer) Gas supply unit (gas supply source for plasma processing) 61 Gas pipe (gas supply path for plasma processing) 62 Gas flow path (gas supply path for plasma processing) 63 Small through hole (for plasma processing) Gas supply path) 70 Cooling device (chiller, liquid cooling device, second temperature control device) 71 Piping (coolant supply / return path, second temperature control means) 72 Liquid flow path ( (Circulating liquid circulation path, second temperature adjusting means) 73 Gap filling material (adhesive, elastic film) 74 Heat transfer member (one of a plurality of stacked members which is closer to the opposing wall) 90 Distribution variable means (adjustment of impedance distribution) Part)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H05H 1/46 H01L 21/302 BF Term (Reference) 4G075 AA24 AA30 AA63 BC04 BC06 CA02 CA03 CA25 CA47 CA65 EB01 FC11 FC15 4K030 FA01 FA03 FA04 GA02 KA08 KA22 KA23 KA26 KA30 KA46 LA15 5F004 BA20 BB13 BB25 BB29 BD01 BD04 CA04 5F045 AA08 BB08 EB02 EH02 EH11 EJ03 EJ04 EJ09 EM09

Claims (3)

[Claims] In a plasma processing apparatus in which a holding portion for an object to be processed and an insulator or semiconductor wall face each other across a plasma processing space in a vacuum chamber, a first temperature control of the holding portion is enabled. Temperature control means, a heat transfer member spread with a gap filler interposed from the opposite side of the plasma processing space with respect to the wall, and second temperature control means capable of controlling the temperature of the heat transfer member. A plasma processing apparatus comprising: 2. The plasma processing apparatus according to claim 1, wherein said heat transfer member comprises a plurality of heat transfer members stacked with a gap filler therebetween. 3. The plasma according to claim 2, wherein, of the plurality of heat transfer members, a member close to the wall has a thermal expansion coefficient close to that of the wall and far from the wall has a high thermal conductivity. Processing equipment.