JPH06124998A - Plasma process equipment - Google Patents

Abstract

PURPOSE:To prevent the permeation of deposit on the rear of a semiconductor wafer substrate, by attracting an object to be processed on a protective ring having electrostatic chuck function, and attracting the object to be processed together with the protective ring on an electrode, with an electrostatic chuck. CONSTITUTION:An object 113 to be processed is fixed on a fixing stage 115 together with a protective ring 114, via the protective ring 114, by electrostatic force. A dipolar electrode is buried in the protective ring 114, and the object 113 to be processed can be fixed with the electrostatic chuck. After the object 113 to be processed is attracted on a stage 115 for fixing an object to be processed, by an applied voltage supplied from a DC power supply 106, the object is cut off from a conveying arm. The protective ring 114 is attracted and fixed on the stage 115 with the electrostatic chuck by applying an voltage from a DC power supply 107. An objecte to be processed 119 also is attracted and fixed with the electrostatic chuck.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a plasma processing apparatus. More specifically, high-frequency power is supplied between opposing electrodes provided in a depressurizable container, plasma is generated between the electrodes, and an object to be treated on the electrodes is treated with the plasma, and The above object to be processed relates to a plasma processing apparatus configured such that the electrode itself can be heated or cooled to control the temperature of the object to be processed.

[0002]

2. Description of the Related Art With the increase in the degree of integration of VLSI, the demand for semiconductor manufacturing equipment for realizing high performance, high reliability and high yield for extremely miniaturized devices has become even greater. There is.

In order to precisely control the dimensions of a fine element and to improve the characteristics and reliability of the element, not only the fine processing technology but also various materials (semiconductor wafer, It is very important to improve the quality of insulating materials and thin metal films. Therefore, in the VLSI manufacturing process, RIE (Reactive IonE)
tching) method, bias sputtering method, plasma CVD (Chemical Vapor Depos)
The weight of processes such as etching or thin film formation using discharge such as the ionization method has been increasing more and more.

In the semiconductor device manufacturing process, thin film formation,
Elemental technologies such as patterning, etching and ion implantation are required. With higher integration, wafers have larger diameters, design dimensions have become deep submicron, ultra-clean compatible, and development of low-temperature process technology capable of processing all processes at low temperatures of 500 ° C or lower is required.

[0005] The thin film forming technology requires metal, semiconductor,
This is to form a high-quality thin film on a fine pattern uniformly over a large area at a high speed regardless of the insulator at a low temperature without damaging or contaminating the underlying substrate.

Further, a demand for the patterning technique is that a fine pattern can be formed accurately and uniformly over a large area under the same exposure condition regardless of the material of the underlying substrate and the shape of the underlying step. Then, the development is performed without damaging or contaminating the base substrate.

Further, the requirement for etching technology is that the fine pattern is faithfully converted to the dimensions of the etching mask without causing a difference, and the etching is performed uniformly over a large area at a high speed.
Moreover, it is to process at a low temperature with a high selection ratio without damaging or contaminating the underlying substrate.

[0008] Further, the requirement for the ion implantation technique is that there is no charge-up of the wafer or metal contamination from the apparatus at all, and the underlying substrate is precisely and uniformly applied to a fine pattern area over a large area at a high speed. That is, high-concentration or low-concentration impurities are implanted at a low temperature at which the temperature of the substrate does not rise without damaging or contaminating. Then, after that, the impurities implanted by the low temperature heat treatment at 500 ° C. or less are completely activated.

In order to satisfy the requirements of these elemental technologies and realize a low temperature process, precise control of the flatness of the wafer and the surface temperature have become indispensable.
That is, it is important to realize the process in which the wafer holding accuracy and the surface temperature uniformity do not fluctuate when the process temperature is lowered, in order to realize the complete control of the process parameters. Therefore, the chucking method using an electrostatic chuck, which can bring the wafer into close contact with the sample stage by electrostatic force, is more effective than the conventional mechanical chucking method that cannot provide precise control functions such as uniformizing the surface temperature of the wafer and correcting flatness. It is needed.

When chucking a wafer, a backside full surface chuck is the basic idea of what an electrostatic chuck should be. This is because the heat flow between the wafer and the sample stage in heating / cooling the wafer, that is, the thermal resistance needs to be uniform. For this purpose, not only the wafer suction surface of the electrostatic chuck but also the back surface of the wafer itself must be completely free of microroughness.

It is also important that the sample stage should be placed in a completely dust-free condition. Grasping anything other than the backside of the wafer not only causes cross contamination and dust generation but also causes nonuniformity of the surface temperature of the wafer. It is clear that the conventional method of chucking a wafer by a mechanical clamp method always causes cross contamination and dust generation because the periphery of the wafer must be suppressed. This is because, for example, the clamp itself becomes a source of metal contamination on the wafer, or scratches the surface of the wafer to become a dust generation source.

The traces of the clamps on the wafer surface may change the film composition and film internal stress in the wafer surface in a certain thin film forming process, or may cause film peeling in the subsequent process to cause a dust generation source. become. Furthermore, the film thickness distribution and the temperature distribution are non-uniform around the clamp, which causes exposure failure and etching non-uniformity during patterning. It also causes the warp of the wafer and induces crystal defects.

In order to avoid such an influence of clamping around the wafer, in the current process, the number of steps of removing the thin film around the wafer by the peripheral exposure technique for each etching step is increased. There is.
Further, regarding the thermal history of the wafer process, a temperature processing cycle is adopted in which a sharp temperature difference does not occur in the wafer itself during the process so that crystal defects are not induced around the wafer during the process.

Therefore, the processing time of the total process of the wafer becomes very long. Also, the chucking method using vacuum adsorption can be used for wafer transfer and fixing at atmospheric pressure, but it cannot be used for elemental processes in vacuum such as dry etching that uses plasma, which will become the mainstream in the future.

As described above, the conventional chucking method using mechanical clamps or vacuum suction not only cannot control the temperature uniformity on the back surface of the wafer with high precision, but also can be used in the semiconductor manufacturing equipment. It is not optimal for cleaning and ultra-cleaning of the wafer surface. However, a ceramics electrostatic chuck that can adhere the back surface of the wafer to the sample stage by electrostatic force is indispensable not only to improve the uniformity of the wafer surface temperature but also to maintain the ultra-clean semiconductor manufacturing equipment. is there.

In recent years, many examples have been reported in which an electrostatic chuck is used in a semiconductor manufacturing apparatus to which plasma is applied.

However, in the electrostatic chuck used in the current plasma process, plasma resistance, heat resistance, thermal response, thermal uniformity, gas releasing property of the ceramic material, and ceramic resistance to the in-situ chamber cleaning gas. ON for corrosive and chucking
/ OFF cuts the insulation life of the ceramic material, high-speed chucking function, removal function of dust deposits on the chuck surface or removal of deposits of reaction by-products during the process, and prevention of wraparound of deposits on the backside of the semiconductor wafer substrate. The situation is that it is not carried out sufficiently.

The problem that occurs in the plasma processing apparatus using the electrostatic chuck according to the prior art will be specifically described by taking the case of growing a silicon thin film by the bias sputtering technique as an example.

FIG. 8 is a schematic diagram of a dual frequency excitation plasma process apparatus. The feature of this device is 1000 l / se
For example, an argon (Ar) gas is supplied to the decompressible container 401 to which a vacuum exhaust device 402 having an evacuation speed of c is connected via a gas introduction port 403 at several cc / min to 10 cc / min.
It is possible to set and introduce in the range of 00 cc / min. At this time, the pressure in the container 401 is several mT.
It is held at orr to 100 mTorr. Plasma
For example, the high frequency power supply 404 of 100 MHz supplies high frequency power in the range of several watts to 500 watts between the opposing electrodes 410 provided in the container 401, and the container 40
It can be generated by efficiently discharging the Ar gas introduced into the chamber 1. The formation of the Si thin film is
Silicon (S) that holds argon ions (Ar ions) generated by the plasma in the upper electrode 412 by utilizing the potential difference generated between the plasma and the target 411.
i) It hits against the target of 411 and the target 411 is sputtered by the kinetic energy. The Si atoms ejected by the sputtering come to the surface of the semiconductor wafer substrate 416 held by the lower electrode 417 and are adsorbed to the semiconductor wafer substrate 416 by utilizing the potential difference generated between the plasma and the semiconductor wafer substrate 416. , Single crystal S
i grow a thin film. Target potential is DC power supply 4
The target value 411 can be set to an arbitrary value, and in practice, the target 411 can be efficiently sputtered by setting the value to several V to 1000V.

Inside the upper electrode, a permanent magnet 414 of several hundred to several thousand Gauss is provided to increase the plasma density on the surface of the target 411. Further, the potential of the semiconductor wafer substrate 416 can be set by changing the high frequency power of the high frequency power supply 407 of 40 MHz, and this can be arbitrarily set within an appropriate positive value to negative value. This makes it possible to irradiate the surface of the Si thin film with Ar ions at an optimum ion energy.
This allows the ion irradiation energy to be set accurately and with good controllability regardless of whether the semiconductor wafer substrate 416 is made of a conductive material or an insulating material. In addition, the lower electrode 41
A DC power source is also connected to 7, so that a DC voltage can be directly applied to the semiconductor wafer substrate.

The Si target 411 is the upper electrode 41.
2 is held by using an electrostatic chuck. The attraction voltage of this electrostatic chuck can be applied by a DC power supply 406. The semiconductor wafer substrate 416 is held on the lower electrode 417 by using an electrostatic chuck. The attraction voltage of the electrostatic chuck can be applied by the DC power supply 409.

On the upper electrode 412 side, a coolant material (for example, cooling water) flows into the upper electrode interior 415 so that the temperature of the Si target itself does not rise during sputtering. A heater 419 is provided on the lower electrode 417 side to maintain the substrate temperature at an appropriate temperature. The heater section 420 has a vacuum exhaust port 42.
1 is provided so that the filament 418 can be evacuated so as not to be oxidized. The filament 418 can heat the electrode 419 integrated with the lower electrode 417 by radiant heating.

However, the above conventional technique has the following problems.

First, in the plasma process, since the ceramic material (for example, alumina ceramics (Al ₂ O ₃ )) forming the electrostatic chuck is exposed to plasma during the process, the surface of the semiconductor wafer substrate is exposed. There is a problem that the ceramic component adheres and the process parameters cannot be completely controlled, resulting in deterioration of high performance, high speed, and high reliability of the device. Any ceramic material will be sputtered when exposed to ions having a high ion irradiation energy of 40 eV or more. For example, in a relatively high energy ion irradiation process such as metal sputtering or reactive ion etching (RIE) which requires an ion irradiation energy of 40 eV or more, sputtering of ceramics occurs.

However, the ion irradiation energy is 40 eV.
Low temperature (eg, 250 ° C.) epitaxial growth by silicon sputtering and halogen-based gas (eg, fluorine (F), chlorine (Cl), bromine (B
In a low ion energy ion irradiation process such as in-situ chamber cleaning using (r) or the like), sputtering of ceramics does not occur. However,
When the ceramics are exposed to plasma while being heated to a high temperature, the ceramics are likely to be sputtered even by irradiation with low ion energy of 40 eV or less, so that there is a problem that contamination of the semiconductor wafer substrate cannot be avoided.

Further, in a ceramic electrostatic chuck that requires heating or cooling, the insulation resistance of the ceramic changes greatly depending on the temperature, so that the attraction force of the semiconductor wafer substrate deteriorates at a certain operating temperature. There is. In order to improve the attractive force of the ceramic electrostatic chuck, for example, we tried a method of mixing a few percent of metal oxide into alumina ceramics, but even in this case, the ceramics are kept in a heated state and exposed to plasma. Then, there is a problem that the metal oxide is sputtered by argon ions and contaminates the semiconductor wafer substrate. Further, since the metal oxide is mixed in the ceramics, conversely, there is a problem that the insulation resistance of the ceramics decreases due to the temperature rise and the adsorption force decreases. The insulation resistance of ceramics has a resistivity of 10 ⁹ to 1 with respect to the operating temperature.
It is necessary to set so that the insulation resistance is optimum within the range of 0 ¹⁵ Ωcm.

When heating a semiconductor wafer substrate,
Since the method of heating the sample stage is radiant heating by a filament, a large amount of filament heating power is required to bring the surface of the semiconductor wafer substrate to an arbitrary set temperature, which causes a problem of poor thermal response. . Further, when the sample stage is heated by such a method, there are problems such as non-uniformity of temperature on the surface of the semiconductor wafer substrate and deterioration of life of the filament. Further, the upper electrode side needs to be sufficiently cooled so that the temperature of the target itself does not rise during the plasma process. This upper electrode is cooled by cooling water via the electrode of the electrostatic chuck. In such a case, if the lower electrode is not heated, the upper electrode can be sufficiently cooled, but if the lower electrode is, for example, 500 ° C.
When heated to a certain degree, the upper electrode is also heated by the radiant heat, so that there is a problem that there is no sufficient cooling effect.

In order to maintain the stability, reproducibility and reliability of the process and to completely control the process parameters, the process chamber is not exposed to the atmosphere, and after each process is completed or after several lots are processed, in- in situ
Therefore, it is necessary to perform cleaning using a halogen-based gas, for example. In the conventional holding method for adsorbing a semiconductor wafer substrate by an electrostatic chuck, when the target material adheres to the ceramic surface having a few pores in the electrostatic chuck portion, even if the in-situ chamber cleaning process by plasma is performed. There is a problem that the deposits cannot be removed sufficiently. Further, if the cleaning time is lengthened to completely remove the deposits, the ceramic itself is corroded, the thickness of the insulating film is reduced, and the dielectric strength is deteriorated. If the adhered matter remains without being removed, the flatness at that portion deteriorates and the suction force also deteriorates.

Further, in the production factory, one electrostatic chuck chucks about 1,000,000 times in one year. In order to maintain process stability, reproducibility, and reliability, an electrostatic chuck that can withstand this number of chucking times is required. In reality, the chuck surface is worn every time chucking occurs, and there is a problem that the dielectric strength is deteriorated by a strong electric field.

In order to shorten the TAT of the total process and the processing time of each process, a high speed chucking function that shortens the adsorption / desorption time of the electrostatic chuck is required. The function of directly mechanically holding and carrying the periphery of the semiconductor wafer substrate causes a problem that the front and back of the semiconductor wafer substrate are rubbed and dust is generated. Also,
The generated dust is brought into the process chamber together with the semiconductor wafer substrate and adheres to the attraction surface of the electrostatic chuck, which causes a problem that the semiconductor wafer substrate is not attracted to the sample stage.

Further, when the periphery of the semiconductor wafer substrate is exposed to the plasma, there is a problem that sputtered Si atoms go around and adhere to the back surface of the semiconductor wafer substrate. Further, if the semiconductor wafer substrate is attached to the back surface and the process proceeds to the next step, the semiconductor wafer substrate will not be attracted to the attraction surface of the electrostatic chuck. Even if the semiconductor wafer substrate is attracted to the attracting surface of the electrostatic chuck, the problem that the uniformity of the surface temperature is deteriorated occurs.

The pin terminals for applying a voltage to the target Si and the semiconductor wafer substrate are in contact with the back surface of the target Si and the semiconductor wafer substrate. In order to maintain airtightness, this pin terminal is connected to ceramics and metal by using, for example, EB welding (electron beam welding). Such a connection method has a problem that when the semiconductor wafer substrate is heated, the pin terminal portion causes nonuniformity of temperature on the surface of the semiconductor wafer substrate.

In order to generate a high density plasma between the opposing electrodes, high frequency power must be efficiently introduced between the opposing electrodes. Since the distance between the matching circuit and each of the electrodes facing each other is long, the reactance component becomes larger as the frequency becomes higher, and there is a problem that high-frequency power is not efficiently introduced between the facing electrodes to cause a loss. Further, since this reactance component is large, it is difficult to adjust the matching circuit to eliminate the reflected wave.

In addition, a metal electrode plate (for example, tantalum or molypden which is a refractory metal) for exciting plasma or adsorbing an object to be processed, which is embedded in each of the electrodes facing each other, is , Which has a thickness of several millimeters, not only the structure of the electrode itself becomes large, but also the efficiency of heating or cooling the object to be processed deteriorates, and the uniform heating property also deteriorates, and further, it is buried. There is a problem that the insulating film peels off due to the difference in thermal expansion coefficient between the metal electrode plate and the insulating film.

The above problems have been found by the present inventor.

[0036]

SUMMARY OF THE INVENTION The present invention is directed to an electrode made of an insulating material (for example, a ceramic material) and provided in a container capable of depressurizing and having an electrostatic chuck function facing each other. Heat resistance, thermal responsiveness, soaking property, insulation life is good, and corrosion resistance of ceramics against in-situ chamber cleaning gas is good, and there is no wraparound of deposits on the back surface of the semiconductor wafer substrate, Another object of the present invention is to provide a plasma processing apparatus capable of absorbing / desorbing an electrostatic chuck at high speed.

[0037]

In the plasma processing apparatus of the present invention, high frequency power is supplied to opposing electrodes provided in a depressurizable container to generate plasma between the electrodes so that the plasma is generated between the electrodes. In a plasma processing apparatus configured to process an object to be processed with the plasma, it is possible to completely control process parameters even when the object to be processed is heated or cooled at a certain optimum temperature in the container. The electrode for plasma excitation and the heater material for heating or cooling the object to be processed are embedded in the same ceramic insulator, and the electrode is composed of the ceramic insulator and has an electrostatic chuck function. The object to be treated is adsorbed on the protection ring equipped with the Characterized in that was.

[0038]

In the present invention, the electrodes for plasma excitation and the heater material capable of heating or cooling the object to be processed are embedded in the same ceramic insulator as the opposing electrodes in the depressurizable container. Therefore, even if the object to be processed is kept at a certain temperature, the uniform heat distribution of the surface of the object to be processed is very good, and complete control of the process parameters can be realized. Further, since the heat conduction to the object to be processed is good, the object to be processed can be heated or cooled with a small amount of electric power,
A system with low power consumption can be realized.

Further, since the embedding pattern of the heater material adopts a non-induction type embedding method which does not generate electromagnetic waves, electromagnetic waves are not generated from the object fixing stage even when the object is heated or cooled, Even when plasma is generated, it is possible to generate and maintain a uniform plasma without disturbance of the electromagnetic field, complete control of process parameters is possible, and it is possible to improve reliability and yield.

Further, in order to protect the workpiece fixing stage from plasma, the workpiece is fixed on the protective ring, and the protective ring and the workpiece are put together on the workpiece fixing stage by an electrostatic chuck. Since it is fixed, it is possible to prevent the breakdown voltage from deteriorating, which causes deposits of spatter to adhere to the workpiece fixing stage and reduces the attractive force of the electrostatic chuck. Since it is set higher than the surface of the object to be processed so that it can enter the plasma, it is possible to prevent the deposits from wrapping around to the back surface of the object and stabilize the electrostatic chuck function of the object fixing stage for a long time. It can be operated and maintenance requires only regular replacement of the protective ring,
It is possible to realize a plasma processing apparatus with a high operation rate that enables maintenance-free processing of the workpiece fixing stage.

When the object to be processed is released from the object fixing stage having the electrostatic chuck function, the object to be processed is placed on the object rather than being directly held by the transfer arm and moved. Since the protection ring is held by the transfer arm so that it can be moved mechanically, high-speed chucking is possible and the processing time of the process can be shortened.

Further, since the insulation resistance of the protection ring is set to be smaller than that of the object fixing stage, heat conduction from the object fixing stage to the object is improved, and the temperature uniformity of the surface of the object is uniform. Since it can be efficiently controlled and ions and electrons escape to the outside through a protection ring with low insulation resistance even during plasma generation, the workpiece fixing stage does not become charged, and it is manufactured on the surface of the workpiece. For example, it is possible to prevent the dielectric breakdown of the insulating film and to manufacture an LSI that operates stably at high speed, so that it is possible to improve reliability and yield.

The conductor for introducing the high frequency power of the electrodes facing each other has, for example, a radius of 10 mm and a length of 5 from the periphery of the back surface of the electrode in order to reduce the reactance component to 1 ohm or less.
Since about 16 0 mm metal conductors were drawn out and connected to the matching circuit, for example, even at a high frequency of 200 MHz, a large high frequency power can be efficiently introduced between the opposing electrodes, and a high density plasma can be generated. It is possible to generate plasma, and it is possible to realize a plasma processing apparatus corresponding to a low temperature process capable of completely controlling process parameters even when an object to be processed is heated to a relatively low temperature.

Although the electrodes facing each other are heated or cooled differently, the electrodes are made up of exactly the same components, for example, a workpiece fixing stage and a protection ring. Since it can be done by using the arm mechanism, not only can the size of the container be made compact, but the number of replacement parts for maintenance can be reduced, so the cost of the device can be lowered, high performance, and multifunctional. A mass production factory with the equipment installed can be realized.

As for the thickness of the metal electrode plate for exciting the plasma embedded in the electrodes facing each other, since a high frequency current due to the skin effect flows on the surface of the conductor, a film having only this skin thickness is used. Thickness is enough. For example, when the frequency is 200 MHz and the buried metal electrode plate is made of tungsten, the skin thickness is 8.18 μm, and thus the thickness of the metal plate needs to be about three times the skin thickness. . Since the metal plate embedded in the electrode is very thin in this way, the electrode itself can be formed with a very thin structure, and heat can be efficiently transferred to the object to be processed. The soaking property of the surface is improved, and a plasma processing apparatus with high process stability and reliability can be realized.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic diagram of a dual frequency excitation type bias sputtering apparatus showing an embodiment of the present invention.
The features of this device have already been described in detail in the prior art and will not be described. Here, the features of the present invention will be described in detail.

The upper and lower electrodes facing each other, which are provided in the depressurizable container 101, are respectively the workpiece fixing stage 11
5, 121 and the protective rings 114, 120, and are made of the same components, although the heating or cooling method is different. The object to be processed 113 is
The protective ring 114 and the protective ring 114 are fixed to the fixed stage 115 by electrostatic force via the protective ring 114. A bipolar electrode is embedded in the protection ring 114, and a DC voltage is applied from a transfer arm (not shown), so that the workpiece 113 can be fixed by an electrostatic chuck.

After the workpiece 113 is attracted to the workpiece fixing stage 115 by the applied voltage supplied from the DC power source 106, the transfer arm is cut off and the protective ring 114 is opened by the applied voltage from the DC power source 107. Adsorption to the workpiece fixing stage 115 by an electrostatic chuck,
It is supposed to be fixed. Further, the object to be processed 119 is also adsorbed and fixed to the object to be processed fixing stage 121 together with the protection ring 120 by an electrostatic chuck by the above method. The replacement of the object to be processed 119 is performed by protecting the object to be processed 119 with an electrostatic chuck.
It is designed to be held by the transfer arm while being adsorbed on the. The insulating films of the workpiece fixing stage 115 and the protective ring 114 may be made of exactly the same material, but in order to prevent the workpiece fixing stage 115 from being charged, the insulating resistance of the protective ring 114 is It is desirable to use a material that is lower than the insulation resistance of the workpiece fixing stage 115.

Further, only the heater material 123 for heating the object 119 is embedded in the object fixing stage 121 on the lower electrode side, but the object 119 is cooled to a low temperature of 0 ° C. or less. Therefore, in addition to the heater material 123, a pipe through which the refrigerant gas flows may be embedded.
Note that the cooling pipe itself may be heated. Since it is only necessary to consider cooling the object 113 on the upper electrode side, not only the cooling water but also any other cooling gas having a cooling effect may be provided in the embedded cooling pipe. Absent.

On the upper electrode side, a permanent magnet in the range of several hundred Gauss to several thousand Gauss is formed inside the electrode in order to generate a high density plasma in order to increase the sputtering speed of the workpiece 113. Although provided, this permanent magnet
It does not necessarily have to be provided inside the upper electrode, and may be provided on both sides between opposing electrodes, or a permanent magnet may be provided outside the container 101 so that a parallel magnetic field can be created between the opposing electrodes. I do not care. Further, although this permanent magnet is fixed so as not to move, it may be provided with a mechanism for rotating so that the plasma density becomes uniform between the opposing electrodes. Further, although the permanent magnet is provided only on the upper electrode side, the permanent magnet may be provided on the lower electrode side. At this time, it goes without saying that a cooling mechanism is provided so that the magnetic flux density of the permanent magnet does not decrease when the lower electrode is heated. A permanent magnet is used to increase the plasma density, but any other magnet may be used as long as it can generate a parallel magnetic field between the opposing electrodes.

FIG. 2 shows a heater material 2 for heating the metal plate electrode 206 for plasma excitation and the object 119 to be processed.
2 is a schematic diagram showing a state in which 02 is embedded in an insulator 201. FIG. In this example, the heater material 202 has a non-induction type embedding pattern so that electromagnetic waves are not generated.
The heater can be divided into two zones and heated in order to efficiently adjust the surface temperature of the center and the periphery of the object to be processed 119 and improve the heat uniformity. That is,
One zone controls between terminals 203a and 203b and the other controls terminals 203b and 20b.
It can be controlled between 3c. In addition, in order to improve the soaking property, even if the heater does not have two heating zones,
More zones may be provided. Heater material 20
As the wire 2, a wire-like material is embedded in the insulator 201, but if the material to be processed 119 can have good thermal uniformity and good thermal conductivity, it may have another shape (for example, a plate or a tube). It doesn't matter.

FIG. 3 is a schematic view showing a state where the metal plate electrode 206 for plasma excitation is embedded in the insulator 201. The insulating film 205 on the metal plate electrode 206 may have a thickness in the range of 100 to 300 μm. As shown in the figure, the terminal 207 for introducing high-frequency power has a structure in which it is drawn from the periphery of the back surface of the electrode, so that it can pass a large amount of high-frequency current even when used at a high frequency, and consumes power. In order to prevent the reactance component from increasing, for example, dozens can be withdrawn so that the reactance component becomes 1 ohm or less. Note that the number of lead terminals may be small at the frequency used. In addition, in this example, a terminal having a diameter of 10 mm was embedded in the insulator 201. However, if there is no problem in coating the metal plate electrode 206 with the insulating film, one having a large diameter may be embedded. Thereby, the number of terminals may be reduced. Further, the buried metal plate electrode 206 exemplifies a plate-like one in this example, but if the self-bias and the plasma density do not change as compared with those containing the plate-like electrode, for example, An electrode having small holes may be used on the plate, or a strip-shaped electrode may be used.

FIG. 4 shows electrode terminals 208a and 208b for applying a voltage to the object to be processed 119, and electrode terminals 210a and 210b for adhering the protection ring 215 to the object fixing stage 121 by the electrostatic chuck.
It is a schematic diagram which shows the position and structure of the electrodes 211a and 211b.

The electrodes 209a and 209b are exposed on the peripheral surface of the workpiece fixing stage 121, and the back surface electrode of the protection ring 215 is in contact with the electrodes 209a and 209b.

The electrodes 211a and 211b are embedded in the insulator of the workpiece fixing stage 121, and the protection ring 215 can be attracted and fixed by an electrostatic chuck. The electrodes 209a and 209b have a structure in which the metal electrode surface is embedded around the object fixing stage 121 with the metal electrode surface exposed, but a voltage is applied to the object 119 via the protection ring 215. Other methods may be used as long as they can be supplied.

FIG. 5 shows electrodes 213a and 213b for applying a voltage to the object 119 to be processed in the protective ring 215 and an electrode 214a for adsorbing the object 119 to the object to be processed 119 to the protective ring 215 by an electrostatic chuck via a transfer arm. 214
It is a schematic diagram which shows the position and structure of b. Electrodes 212a, 2
12b is the object 11 to be processed of the object fixing stage 121.
9 is an electrode in contact with electrodes 209a and 209b (FIG. 4) for applying a voltage to 9.

In the above embodiment, the case where the bias sputtering apparatus is used has been described.
Using plasma, for example, RIE technology, plasma CV
It goes without saying that the same effect can be expected by using D technology, CVD or etching technology using ECR, reactive bias sputtering technology, or the like. Although the Si substrate is used as the object to be processed, a compound semiconductor or a material other than the semiconductor may be used.

Further, in FIG. 6, the film-shaped heater 504 in which the heating part is in one zone is shown as the first insulating film 5.
It is a schematic diagram which shows the electrode structure when it embeds in 01. The metal film-shaped heater material 504 is adhered by sandwiching a second insulating film 503 (eg, aluminum nitride (AlN)) on a metal plate electrode 502 (eg, tungsten (W)) for plasma excitation. is there. In this adhesion method, first, for example, a plasma spraying method is used to coat the back surface of the metal plate electrode 502 for plasma excitation with a second insulating film 503 of several tens of microns, and then the same plasma spraying method is continued. The metal that becomes the heater at (for example, N
iCr) is coated on the insulating film 503 in the range of several tens to several hundreds of microns. Lead-out terminals 505a, 505b, 505C, 505d, 5 for heating the metal film-shaped heater material 504.
No. 05e is provided with one terminal at the center and four terminals at the periphery, and is configured so that a current flows evenly through the metal film to improve the thermal uniformity of the object to be processed.

Further, FIG. 7 shows that the heaters 604, 6 in the form of metal films are divided into three zones in the heating section.
It is a schematic diagram which shows the electrode structure when 06 and 608 are embedded in the 1st insulating film 601. The method of making this electrode is the same as that described in FIG. First, the second insulating film 6 is formed on the back surface of the metal plate electrode 602 for plasma excitation.
03 using, for example, a plasma spraying method, and then using the same spraying method, metal films 604, 606, and 608 to be heating heaters are successively applied to the second insulating film in the range of several tens of microns to several hundreds of microns. This is done by coating on 603. Two lead terminals for heating the metal film heater are provided for each zone. The heater is divided into three zones in order to control the heating temperature in each zone to make the surface temperature of the object to be treated uniform.

The material of the metal film heater may be different from the material of the metal plate electrode for plasma excitation, but it is preferably the same material and the thermal expansion with the first insulating film. It suffices if the coefficients are almost the same or close. Further, in order to improve the temperature uniformity of the surface temperature of the object to be treated, the material of the metal film heater in the three zones may be completely different materials. Even in the case of a metal film heater in one zone, the thickness of the metal film is made different between the central portion and the peripheral portion in order to make the surface temperature of the object to be treated uniform. Alternatively, films having different film qualities may be stacked.

The material of the first insulating film and the second insulating film is preferably an insulating film having the same coefficient of thermal expansion as that of the metal, considering the difference in coefficient of thermal expansion between the buried metal and the metal.
Insulating films made of different materials may be used. The electrode embedded in the first insulating film has a three-layer structure of a metal plate electrode / second insulating film / metal film electrode, but the difference in thermal expansion coefficient is relaxed. Any number of layers may be used as long as it is a method. Although a metal plate or a metal film is embedded in the first insulating film for the purpose of heating the object to be processed, when cooling is considered, instead of the metal plate, a metal plate A method of embedding a metal plate having a hollow inside so that a refrigerant material can flow therein may be used. Needless to say, when cooling, it is necessary to have a function of heating the electrode itself for cooling in order to keep the temperature at a constant temperature.

[0063]

According to the present invention, plasma resistance, heat resistance, thermal response, thermal uniformity, insulation life are good, and i
Provided is a plasma processing apparatus which has good corrosion resistance of ceramics to an n-situ chamber cleaning gas, does not wrap around a deposit on the back surface of a semiconductor wafer substrate, and is capable of absorbing and desorbing an electrostatic chuck at high speed. be able to.

[Brief description of drawings]

FIG. 1 is a schematic view of a dual frequency excitation type bias sputtering apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state where a metal plate electrode for plasma excitation and a heater material for heating an object to be processed are embedded in an insulator.

FIG. 3 is a schematic view showing a state where a metal plate electrode for plasma excitation is embedded in an insulator.

FIG. 4 is a schematic view showing positions and structures of electrode terminals for applying a voltage to an object to be processed and electrode terminals for adhering a protection ring to an object fixing stage by an electrostatic chuck, and electrodes.

FIG. 5 is a schematic view showing positions and structures of electrodes for applying a voltage to an object to be processed in the protection ring and electrodes for adhering the object to be processed to the protection ring by an electrostatic chuck via a transfer arm.

FIG. 6 is a schematic diagram showing an electrode structure when a film-shaped heater having a heating section in one zone is embedded in a first insulating film.

FIG. 7 is a schematic view showing an electrode structure when a metal film-shaped heater material having a heating section divided into three zones is embedded in a first insulating film.

FIG. 8 is a schematic view of a plasma processing apparatus with dual frequency excitation.

[Explanation of symbols]

106 DC power supply, 107 DC power supply, 113 processed object, 114,120 protective ring, 115,121 processed object fixing stage, 119 processed object, 121 processed object fixing stage, 123 heater material, 201 insulating material, 202 heater Material, 203a terminal, 203b terminal, 203c terminal, 205 insulating film, 206 metal plate electrode, 208a electrode terminal, 208b electrode terminal, 209a electrode, 209b electrode, 210a electrode terminal, 210b electrode terminal, 211a electrode, 211b electrode, 213a electrode , 213b electrode, 215 protection ring, 401 depressurizable container, 402 vacuum exhaust device, 403 gas inlet, 404 high frequency power supply, 405 DC power supply, 409 DC power supply, 410 electrode, 411 target, 412 upper electrode, 414 permanent Stone, 416 wafer substrate, 417 lower electrode, 418 filament, 419 heater (electrode), 420 heater part, 421 vacuum exhaust port, 501 first insulating film, 502 metal plate electrode, 503 second insulating film, 504 heating heater Material, 505a, 505b, 505C, 505d, 505e
Lead terminal, 601 first insulating film, 602 metal plate electrode, 603 second insulating film, 604, 606, 608 heating heater material.

Claims (5)

[Claims] 1. A plasma is generated between the electrodes by supplying high-frequency power between opposing electrodes provided in a depressurizable container, and an object to be treated between the electrodes is treated with the plasma. In the plasma processing apparatus configured as described above, adsorption means for statically fixing the object to be processed is provided to the opposing electrodes provided in the container, and the electrode itself is capable of heating or cooling temperature control. A plasma processing apparatus provided with means. 2. The object to be treated is attracted by electrostatic force to an opposing electrode embedded in an opposing electrode provided in the container, the opposing electrode having at least a surface formed of an insulator. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is configured. 3. The temperature control means is capable of being heated or cooled embedded in at least the same insulating material provided with at least the adsorption means, which is embedded in the opposing electrodes provided in the container. The plasma processing apparatus according to claim 1, wherein the resistor is configured to be temperature-controlled. 4. The object to be processed is conveyed while being adsorbed on an auxiliary ring formed of an insulator configured to be adsorbed by static electricity. Plasma processing equipment. 5. The plasma processing apparatus according to claim 4, wherein the auxiliary ring is configured to be attracted to the opposing electrodes provided in the container by electrostatic force.