JP2001257253A - Wafer processing device and method of manufacturing wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wafer processing device and a method of manufacturing a wafer that achieves excellent responsivity in addition to stable and precise control of a temperature of a processed wafer. SOLUTION: The wafer processing device having a processing chamber 9 for performing plasma processing on a wafer 1, a means 10 for generating plasma in the processing chamber 9, and a wafer stage 2 for placing the wafer 1, comprises refrigerant channels 15 which are disposed in the wafer stage 2 and have refrigerant flowing therein, and a plurality of heat exchangers 21 and 22 connected to the refrigerant channels 15. A temperature of the wafer 1 is controlled by the plurality of heat exchangers 21 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing semiconductors and the like, and is particularly suitable for a wafer processing apparatus and a wafer manufacturing method for controlling a wafer temperature during wafer processing.

[0002]

2. Description of the Related Art With the recent increase in the degree of integration of semiconductor devices, circuit patterns have been miniaturized, and the required processing dimensional accuracy has become increasingly strict. Becomes very important. For example, in an etching process that requires a high aspect ratio, a process of performing etching while protecting the side walls with an organic polymer to realize anisotropic etching is known, but the generation of the organic polymer varies with temperature. ,
If the temperature control of the wafer during processing is insufficient, the protective film on the side wall varies between wafers, and as a result, the reproducibility of the etched shape may be deteriorated.

As a method of coping with a rise in the temperature of a wafer during processing, a method of circulating a coolant controlled at a constant temperature by a temperature controller in a wafer stage in a recent semiconductor manufacturing line has been applied. When the capacity of the refrigerant is increased to some extent, even if there is a sudden heat input to the wafer, the heat capacity of the refrigerant is large and the temperature stability is good. It is difficult to control well, that is, it is difficult to control the temperature of the wafer stage with good responsiveness. As a method of controlling the temperature of the wafer stage with good responsiveness, there is known a method of loading a wafer as an object to be processed on an electrostatic chuck provided on a thermoelectric element on an electrode and processing the wafer. 4-87321.

[0004]

In the above prior art, since the thermoelectric element can be mounted only on a surface corresponding to the entire area of the back surface of the wafer at the maximum, the thermoelectric element is used in a process having a very large heat input. In such a case, the temperature of the wafer cannot be sufficiently controlled. Specifically, the current heat absorption of the thermoelectric element at present is about 4 W / cm ² at the maximum. However, for example, in a dry etching apparatus for an oxide film, heat input may be 5 W / cm ² or more. It is substantially impossible to arrange the thermoelectric element on the wafer stage so as to absorb the heat that is heated. Therefore, the temperature of the wafer being processed increases, which causes deterioration of the etching characteristics.

[0005] Further, since thermal stress is repeatedly applied to the thermoelectric element, the structure such as the bonding portion between the P-type semiconductor and the N-type semiconductor may be broken due to fatigue. Further, when the thermoelectric element is directly mounted on the back surface of the wafer stage as in the above-described conventional technique, it takes a great deal of time to replace the thermoelectric element, and the entire apparatus must be completely stopped during the replacement. The operation rate of the device will be greatly reduced.

An object of the present invention is to provide a wafer processing apparatus and a wafer manufacturing method which not only can stably and accurately control the temperature of a wafer during processing, but also have a high responsiveness.

Another object of the present invention is to enable operation without dew condensation on a pipe flowing into a wafer stage. It is another object of the present invention to reduce the thermal resistance between the wafer and the wafer stage, and to improve the temperature controllability of the wafer during processing. It is a further object of the present invention to provide a simpler structure.

It is an object of the present invention to solve at least one of the above problems or objects.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a processing chamber for performing plasma processing on a wafer, a means for generating plasma in the processing chamber, and a wafer processing apparatus having a wafer stage for loading a wafer. The apparatus includes a coolant flow path provided in the wafer stage and through which a coolant flows, and a plurality of heat exchangers connected to the coolant flow path, wherein the temperature of the wafer is controlled by the plurality of heat exchangers. is there.

Thus, since a plurality of heat exchangers are connected to the refrigerant flow path, on the one hand, it responds stably to a sudden change in the amount of heat input, and on the other hand, it responds to the wafer with good responsiveness as necessary. If the temperature is controlled, the temperature of the wafer can be controlled with sufficient responsiveness even in a process with a large heat input.

The present invention also provides a wafer processing apparatus having a processing chamber for performing plasma processing on a wafer, a means for generating the plasma in the processing chamber, and a wafer stage on which the wafer is loaded. A refrigerant flow path through which the refrigerant flows, a first heat exchanger having a container that is connected to the refrigerant flow path and stores the refrigerant, and is connected in series with the first heat exchanger, and is disposed immediately before the refrigerant flows into the wafer stage. And a second heat exchanger.

Thus, the first heat exchanger having the container for storing the refrigerant allows the second heat exchanger to prevent the temperature of the refrigerant from rising rapidly even when the amount of heat input to the wafer changes. Since the temperature of the refrigerant immediately before flowing into the wafer can be controlled, not only the temperature of the wafer during the plasma processing can be controlled with good stability but also with good responsiveness.

Further, the present invention provides a refrigerant flow path provided on the wafer stage, through which a refrigerant circulates, a first heat exchanger having a container connected to the refrigerant flow path for storing the refrigerant, and a series of the first heat exchanger. And a second heat exchanger having a thermoelectric element arranged to heat and cool the refrigerant.

Further, in the above-mentioned apparatus, it is desirable from the viewpoint of dew condensation that the pipe through which the refrigerant flows in the refrigerant flow path is vacuum-insulated.

Further, in the above, it is desirable to introduce a cooling gas to a position on the wafer stage which is to be the back surface of the wafer and to subject the wafer to plasma processing.

Further, in the above, the wafer stage is made of a conductive material, and comprises a dielectric film provided on the surface of the wafer stage, and means for giving a potential difference between the wafer stage and the wafer. It is desirable to fix the wafer by the electrostatic force of the charge stored between the film and the wafer.

Further, the present invention is a wafer manufacturing method for loading a wafer on a wafer stage and performing plasma processing on the wafer while controlling the temperature immediately before the coolant flows into the wafer stage. The temperature of the wafer stage is controlled in relation to the measurement result.

Further, in the above, it is desirable that the temperature control immediately before is performed based on the procedure of the plasma processing applied to the wafer.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 3 show a first embodiment of the present invention, and FIG. 1 is a sectional view of an example in which the first embodiment of the present invention is applied to a plasma processing apparatus. FIG. 2 is an enlarged sectional view of the inside of a heat exchanger using the thermoelectric element of the first embodiment, and FIG. 3 is a perspective view of the heat exchanger of FIG.

A wafer stage 2 on which a wafer 1 being processed is mounted is fixed on a flange 5 tightened by bolts 4 via an O-ring 3. The wafer 1 is mounted on the wafer stage 2, and the wafer 1 is exposed to the plasma 6 to perform an etching process on the wafer surface. 7 is wafer 1
Is a guide for preventing the wafer stage 2 from shifting from the wafer stage 2. Reference numeral 8 denotes a high-frequency power supply for applying a high-frequency voltage to a disk-shaped electrode 10 provided inside the vacuum chamber 9, and generates a plasma 6 in the vacuum chamber 9 by applying a high-frequency voltage to the electrode 10. .

Numeral 11 denotes a gas pipe for introducing a processing gas into the vacuum chamber. Numeral 13 denotes a turbo-molecular pump for evacuating the vacuum chamber. 9 can be set arbitrarily. Since the wafer 1 being processed is heated by the heat input from the plasma 6, it is necessary to measure and adjust the temperature of the wafer 1 being processed in order to realize an etching process with good reproducibility.

The thermocouple 14 is used to measure the temperature of the wafer.
Is used to monitor the temperature of the flange 5. What should be actually measured is the temperature of the wafer 1. However, if the correlation between the temperature at the position measured by the thermocouple 14 and the temperature of the wafer 1 is obtained in advance, the wafer temperature can be predicted without directly measuring the temperature of the wafer. It is. A coolant channel 15 is provided in the wafer stage, and a coolant controlled at a constant temperature is flowed by a heat exchanger outside the vacuum chamber, and the wafer stage is cooled. Two through holes through which a coolant flows into the wafer stage are provided below the flange 5, one of which is a coolant inflow hole 16 and the other is a coolant outflow through hole 17.
It is. Piping 2 tightened with bolts 19 through O-rings 18 in both inflow through hole 16 and outflow through hole 17
0 and 28 are connected, and their opposite ends are connected to a refrigerant outlet 23 of the second heat exchanger 21 and a refrigerant return port 24 of the first heat exchanger 22. Further, the same pipe 26 as that connected to the lower part of the flange is also connected to the refrigerant inlet 25 of the second heat exchanger 21,
This opposite end is connected to the refrigerant outlet 27 of the first heat exchanger. The pipes 20, 26, and 28 have a configuration in which a pipe 29 for a refrigerant flow path is built in a hollow pipe, and the hollow portion is further connected to vacuum pumps 32, 33 via valves 30, 31, and is evacuated. . This is to prevent dew condensation around the refrigerant flow pipe when the refrigerant temperature is low.

The configuration of the first heat exchanger 22 will be described. The first heat exchanger stores the refrigerant 34 in the container 35, cools the refrigerant 34 by the refrigerator 36, heats the refrigerant 34 by the heater 37, and discharges the refrigerant 34 from the refrigerant outlet 27 by the pump 38. The cooling capacity of the refrigerator 36 is 3 kW.
Also has a heating capacity of 3 kW. This value is a standard value as a capability of the temperature controller of the wafer stage for the etching apparatus, but is a value to be appropriately selected depending on use conditions.

The first heat exchanger has a large heat capacity because the refrigerant contains a large amount of refrigerant in the container. Therefore, even if the amount of heat input to the wafer changes, if the refrigerant is circulating, the first heat exchanger will be abrupt. The temperature of the wafer can be kept constant without increasing the temperature of the coolant. However, it is difficult to control the temperature of the wafer with good responsiveness due to the large heat capacity. To control with good responsiveness, the second heat exchanger 21 is provided.

The refrigerant inlet 25 of the second heat exchanger 21 is connected to the refrigerant outlet 27 of the first heat exchanger 22,
Refrigerant flows into the container. The coolant outlet 23 on the opposite side is connected to the through hole 16 so that the flange 5 flows in, and sends the coolant cooled by the second heat exchanger to the wafer stage 2.

As shown in FIG. 3, the second heat exchanger has a rectangular parallelepiped structure surrounded on all sides by side plates, and the refrigerant flows in from the lower pipe 26 and flows out from the upper pipe 28. Three
9 is a pipe for evacuating the inside by a vacuum pump 33 connected via a valve 31. Reference numeral 40 denotes a current introduction terminal for applying a DC voltage to the internal thermoelectric element. Inside the second heat exchanger 21, a container 41 for cooling the refrigerant is incorporated, and around the container 41, a thermoelectric element in which an N-type semiconductor element 42 and a P-type semiconductor element 43 are connected in series is provided. It is in contact via the heat transfer plate 44. The thermoelectric element is connected to an external DC power supply 45 via a current introduction terminal 40, and heats and cools the electric heating plate 44 by changing the polarity of the applied voltage. The heating and cooling capabilities of the thermoelectric element are controlled by controlling the power applied to the thermoelectric element. As a method of controlling the temperature of the wafer, the temperature of the flange 5 is measured by a thermometer 46 connected to the thermocouple 14, the temperature of the wafer is predicted by the processing of a computer 47, and the DC power supply 45 It is good to control the output. That is, the temperature during the processing of the wafer is feedback-controlled.

In this embodiment, conductive vacuum grease is applied thinly between the heat transfer plate 44 and the container 41 in order to secure heat conduction between the heat transfer plate 44 and the container 41. For example, a method of securing heat conduction by, for example, pressing down on the substrate may be used. In any case, care should be taken to ensure that the heat transfer between the heat transfer plate and the container is sufficiently ensured by some means. A pipe 49 is buried inside the heat transfer plate 48 on the opposite side of the thermoelectric element from the side in contact with the container, and circulates water 51 for releasing heat absorbed from the refrigerant to flow the temperature of the thermoelectric element. Preventing the rise. In this embodiment, water is used for cooling the heat transfer plate. However, air may be blown into the pipe for air cooling, or a refrigerant other than water may be used. In addition,
50 is a 0 ring.

Although the number of thermoelectric elements and the connection method are not described in detail in this embodiment, the number of thermoelectric elements corresponding to the required cooling capacity may be connected in series or in parallel. Good. However, when connected in parallel, there is a merit that the operation can be continued without losing the entire cooling capacity even in the event that one thermoelectric element fails. In this case, if the thermoelectric element that failed when the operation of the apparatus was stopped for other reasons is replaced and repaired, the operation rate of the apparatus is not reduced.

A first heat exchanger having a container for storing a refrigerant and a second heat exchanger for heating and cooling the refrigerant by a thermoelectric element are arranged just before the second heat exchanger flows into the wafer stage. In the wafer stage configured to be connected in series as described above, since the first heat exchanger is equipped with a container for storing the refrigerant, the heat capacity of the refrigerant is somewhat large and the heat input to the wafer increases rapidly. In this case, not only the temperature is stable, but also the temperature of the coolant flowing into the wafer stage can be changed with good responsiveness by controlling the power supplied to the thermoelectric element.

Further, since the second heat exchanger provided with the thermoelectric element is connected to the wafer stage via a pipe, even if it breaks down, it can be easily replaced, and the operation of only the first heat exchanger can be performed. Accordingly, the operation of the processing apparatus can be performed, so that a decrease in the operation rate of the apparatus can be prevented.

Further, the control of the electric power supplied to the thermoelectric element is extremely controllable if the feedback control is performed in connection with the result of measuring the temperature of the wafer or a portion where the temperature of the wafer can be predicted or based on the result. The wafer stage can be excellent in quality. Further, since the pipe through which the refrigerant flows is arranged in a vacuum, no condensation occurs even when the low-temperature refrigerant is circulated.

An example of an etching process which can be realized by using the wafer processing apparatus according to the first embodiment will be described. FIG. 8A is a cross-sectional view of a gate electrode of a conventional semiconductor memory, in which 80 is a silicon substrate, 81 is an insulating oxide film, 82 is polysilicon serving as an electrode, and 83 is metal connected to wiring. Silicide. However, it is necessary to increase the current density flowing through the gate electrode in order to increase the density and speed of the device, and a metal having a lower resistance than the metal silicide has been used instead of the metal silicide. For example, FIG. 8B is a cross-sectional view of a structure that is replaced with a conventional gate electrode structure, and includes an insulating oxide film 81, polysilicon 84, and a metal silicide 8.
5. It has a structure of metal 86. Here, the metal silicide 85 is used to secure the adhesion between the polysilicon 84 and the metal 86.

In order to realize the conventional electrode structure as shown in FIG. 8A, a polysilicon film and a metal silicide film are formed on an insulating oxide film and then a resist 8 is formed on the metal silicide.
7, a pattern was formed, and the metal silicide and polysilicon were etched into a desired pattern by controlling the wafer at a temperature of about room temperature using a gas mainly composed of chlorine gas. On the other hand, in FIG. 8B, after a film of polysilicon, metal silicide, and metal is formed on the insulating oxide film, a resist pattern is formed on the metal and etched.
However, a gas mainly containing sulfur hexafluoride is used for metal etching to lower the wafer temperature to a lower temperature (-10 ° C.).
Etching) is more efficient, and differs from the etching of metal silicide or polysilicon in the type of gas used and the temperature condition of the wafer. Therefore, in order to etch with a conventional device, after the metal etching is completed,
Before etching the metal silicide, a waiting time for raising the set temperature by about 10 ° C. is required.

An example according to the present embodiment will be described. The material of the wafer stage is aluminum, the material of the flange is stainless steel, and the total heat capacity is 6 kJ / K. Also,
The heat capacity of the refrigerant contained in all the containers and pipes of the first heat exchanger is 30 kJ / K. In this case, the heater of the first heat exchanger acts to heat the refrigerant, but the time required to heat the total heat capacity of 36 kJ / K at 3 kW is 120 seconds. That is, at least this time is a dead time that does not contribute to the actual etching, which causes a reduction in the processing capability of the apparatus. In contrast, when the second heat exchanger is provided as in the first embodiment, the refrigerant having a temperature of about 10 ° C. flowing out of the first heat exchanger is cooled to room temperature using the second heat exchanger. What is necessary is just to send the refrigerant whose temperature has been adjusted to a certain degree to the wafer stage.

In this embodiment, the container capacity of the second heat exchanger is 3 liters, the flow rate of the refrigerant is 3 liters per second, and the heat capacity of the refrigerant heated and cooled per unit time in the second heat exchanger is 5 liters. 0.4 kJ / K. Therefore, it takes only 5.4 seconds to heat it by the heating function (10 kW) of the second heat exchanger. This time has little effect on the whole process. That is, the processing capability of the apparatus can be utilized to the maximum.

In the above description, whether the set temperature of the first heat exchanger is raised by about 10 ° C. in the same manner as the set temperature of the second heat exchanger may be appropriately determined by a subsequent process. In addition, the stability of the apparatus is increased by setting the time for controlling the temperature of the refrigerant using the second heat exchanger to be shorter in the entire process, so that, for example, in the present embodiment, Conversely, in the first heat exchanger, the coolant is set to the temperature at which the metal silicide is etched, and only when the metal to be etched first is used, the temperature is adjusted to about 10 ° C. lower by using the second heat exchanger. But it is good.

Further, in the above-described process, an example in which three types of films of metal, metal silicide, and polysilicon are successively etched has been described. However, when the type of film to be etched changes, the plasma processing may be temporarily stopped. . That is,
In the above example, the difference in the set temperature was at most about 10 ° C. However, if the temperature difference is larger and it takes about several seconds in view of the capacity of the second heat exchanger, the plasma is once cut off and the wafer Set the stage temperature to the desired value.

In this method, since there is no heat input from the plasma while the temperature of the refrigerant is being controlled, the set temperature can be reached more quickly. Uncontrolled etching can be prevented from progressing while the temperature is being controlled. If the gas type needs to be changed, the gas can be completely replaced in the meantime.
And so on.

Although the above embodiment has been described as an example in which the gate electrode of the semiconductor memory is processed, the present invention is not limited to this and may be used for processing another structure made of another material.

In this embodiment, not only is the first heat exchanger provided with a container for storing the refrigerant but also the refrigerant can be actually heated and cooled. A container for simply storing the cooled refrigerant and a second heat exchanger having the same configuration as that of the first embodiment are connected in series, and the temperature of the refrigerant is all controlled by the second heat exchanger. But it is good. In this case, the cooling capacity of the first embodiment cannot be expected because the first heat exchanger is omitted, but the heat input to the wafer is rapidly increased by the heat capacity of the refrigerant stored in the container. Even if the temperature increases, the temperature of the refrigerant can be controlled relatively stably.

FIG. 4 shows an example of a control method different from the control method of the thermoelectric element of the first embodiment. In this embodiment, information from a thermometer 46 and information from a processing control device 53 for automatically operating an etching process are sent to a computer 52 for controlling a DC power supply 45 for supplying power to a thermoelectric element. . The computer 52 determines temperature information of a wafer to be set next based on information from the processing control device 53, for example, a procedure of plasma processing to be performed on the wafer, compares the temperature with the current temperature, and discharges the information from the second heat exchanger. A time delay between the coolant temperature to be performed and the wafer temperature is predicted, and the coolant temperature is adjusted in advance.

As a result, the temperature control of the wafer can be optimized, and the etching characteristics can be further improved.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, a wafer stage of the present invention is applied to the same plasma processing apparatus as in the first embodiment. A flange 55 is attached to a vacuum chamber 9 via an O-ring 54, and an insulating plate 56 is mounted on the flange 55. The first embodiment is different from the first embodiment in that a dielectric film 57 is attached to the surface of the wafer stage 58 and a wafer stage 58 having an electrostatic chuck function is fixed with bolts 59.

Further, a flange 55, an insulating plate 56,
A through hole 60 is provided in the wafer stage 58, and a pipe 62 is connected to the flange via a mass flow controller 61 for controlling the flow rate of helium gas supplied from a helium gas supply mechanism (not shown).

Further, a DC voltage can be applied to the wafer stage 58 from an external DC power supply 65 by a power supply rod 64 embedded in an insulating pipe 63 penetrating through the flange and the insulating plate. A high-frequency power supply 67 can be connected to a conducting wire 66 for supplying a high-frequency voltage. Reference numeral 68 denotes a coil for preventing high-frequency current from flowing into the DC power supply.
Is a blocking capacitor.

When a processing gas is introduced into the vacuum chamber and a negative voltage is applied to the wafer stage while plasma is generated by applying a high-frequency voltage to the electrodes, a potential difference is generated between the wafer stage and the wafer via the plasma. Since the polarization charge is generated in the dielectric film, the wafer is electrostatically adsorbed and fixed on the surface of the dielectric film. At this time, since a high frequency voltage is applied to the wafer stage, a bias voltage is generated on the wafer, and ions in the plasma can be effectively drawn in, so that etching can be performed more effectively. However, at the same time, the amount of heat input to the wafer increases, so the temperature rise of the wafer increases, so helium gas is injected between the back surface of the wafer and the dielectric film to effectively release the heat input to the wafer to the wafer stage. Introduce. By doing so, the thermal resistance to the wafer and the dielectric film, that is, the wafer stage is reduced, and the wafer can be cooled effectively.

In the above-described wafer stage, the thermal resistance between the wafer and the wafer stage is reduced, and the cooling efficiency of the wafer is increased. Therefore, the wafer temperature is more responsive and more controllable than in the first embodiment. Can be controlled.

FIG. 6 shows a third embodiment of the present invention. The present embodiment is different from the first embodiment in that instead of circulating the cooling water through the pipes in the heat transfer plate for cooling the thermoelectric elements in the second heat exchanger, the refrigerant discharged through the wafer stage is circulated. This is different from the second embodiment. Coolant outflow hole 1 for flange
7 is connected to a refrigerant inlet 70 provided on a side plate of the second heat exchanger, and a refrigerant outlet 71 provided on the side plate is connected to the first heat exchanger. Is connected to the refrigerant return port 24. These pipes have a hollow structure as in the first and second embodiments, and can be evacuated by a vacuum pump 73 connected via a valve 72.

In the wafer stage configured as described above, since equipment such as circulating water is not required for cooling the thermoelectric element, the configuration of the apparatus is simplified.

FIG. 7 shows a fourth embodiment of the present invention. In the present embodiment, unlike the third embodiment, the outflow through hole 17 of the flange 55 and the refrigerant inlet 70 of the second heat exchanger 21 are different.
And the refrigerant return port 2 of the first heat exchanger 22
A pipe 75 connecting the fourth and the refrigerant outlet 71 of the second heat exchanger
Are provided. The pipes 74, 75, 76 are provided with valves 77, 78, 79 for flowing and stopping the refrigerant, respectively.

When the heat input to the wafer is smaller than expected at first and the temperature control by the second heat exchanger is unnecessary,
When the refrigerant whose temperature rises and circulates in the wafer stage circulates in the second heat exchanger, the refrigerant that has been temperature-controlled by the first heat exchanger and has flowed out flows into the second heat exchanger before flowing into the wafer stage. In some cases, the temperature may increase due to heating at the portion. In such a case, if the valves 77 and 79 are closed and the valve 78 is opened to allow the refrigerant flowing out of the wafer stage to return directly to the first heat exchanger 22 without flowing into the second heat exchanger, Unnecessary rise in the temperature of the refrigerant before flowing into the wafer stage can be prevented. Of course, as described above, when it is necessary to control the temperature of the wafer by the second heat exchanger, the operation of the valve may be reversed.

In this wafer stage, the temperature control of the wafer using only the first heat exchanger and the temperature control of the wafer using the second heat exchanger together can be appropriately selected according to the amount of heat input to the wafer.

In the embodiment described above, the temperature of the wafer is not directly measured. For example, a through hole is provided in the flange and the wafer stage, and a fluorescent thermometer is embedded in the through hole. The temperature of the back surface of the wafer may be directly contacted, or a thermocouple may be directly contacted with the back surface of the wafer instead of the fluorescent thermometer.

Although the description has been made assuming that only one flow path for the refrigerant in the wafer stage flows, the flow path of the refrigerant is divided into two systems near the center and the outer periphery of the wafer stage. It is also good. In this case, for example, under normal temperature conditions, the temperature tends to increase near the outer periphery of the wafer. Therefore, it is preferable to apply the present invention only to cooling the refrigerant flowing through the outer flow path from the viewpoint of efficiency and the like. Further, if the present invention is applied to the temperature control of the refrigerant flowing in the flow path near the outer periphery and near the center, it is possible to set the temperatures near the center and the outside to different temperatures. Furthermore, although a plasma etching apparatus has been described as an application example of the present invention, the present invention can also be applied to a stage of another processing apparatus, for example, a CVD apparatus, an electronic drawing apparatus, a liquid crystal glass substrate processing apparatus, or the like.

[0055]

As described above, according to the present invention, it is possible to stably and accurately control the temperature of a wafer during processing, and to obtain a wafer processing apparatus and a wafer manufacturing method with good responsiveness. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment according to the present invention.

FIG. 2 is an enlarged sectional view of a second heat exchanger of FIG. 1;

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a block diagram showing a control method according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view of the first embodiment according to the present invention.

FIG. 6 is a cross-sectional view of the first embodiment according to the present invention.

FIG. 7 is a cross-sectional view of the first embodiment according to the present invention.

FIG. 8 is a sectional view showing an example of etching in an embodiment according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wafer 2 ... Wafer stage 5 ... Flange 6 ... Plasma 7 ... Guide 8 ... High frequency power supply 9 ... Vacuum chamber 11 ... Gas piping 13 ... Turbo molecular pump 14 ... Thermocouple 15 ... Refrigerant flow path 16 ... Inflow through hole 17 ... Outflow through-hole 20 ... Piping 21 ... Second heat exchanger 22 ... First heat exchanger 23 ... Refrigerant outlet 24 ... Refrigerant return port 25 ... Refrigerant inlet 26 ... Pipe 27 ... Refrigerant outlet 28 ... Pipe 29 ... piping 34 ... refrigerant 35 ... container 37 ... heater 70 ... refrigerant inlet 71 ... refrigerant outlet

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shinichi Suzuki 6-16-16 Shinmachi, Ome-shi, Tokyo Inside the Device Development Center, Hitachi, Ltd. (72) Masanori Katsuyama 6--16 Shinmachi, Ome-shi, Tokyo 3 Hitachi, Ltd. Device Development Center (72) Inventor Ken Yoshioka 794, Higashi Toyoi, Kazamatsu, Kudamatsu City, Yamaguchi Prefecture Incorporated Hitachi, Ltd. 794, Higashi Toyoi, Katsumatsu, Katsumatsu, Yamaguchi Prefecture Inventor, Saburo Kanai Inside the Kasado Plant of Hitachi, Ltd. (72) Inventor Ryoji Nishio 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Inside of the Mechanical Research Laboratory, Hitachi, Ltd. (72) Tetsuto Usui 502, Kandate-cho, Tsuchiura-shi, Ibaraki Co., Ltd. Inside Hitachi Machinery Research Laboratory (72) Inventor Hiroki Kawada 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. (72) Inventor Kazuyuki Ikenaga 502 Kandachi-cho, Tsuchiura-shi, Ibaraki F-Term (Mechanical Research Laboratories) Hitachi Machinery Research Laboratories 5F004 BA04 BB13 BB25 BB26 CA04 CB12 5F031 CA02 HA16 HA38 HA39 JA01 JA46 MA32 NA05

Claims (8)

[Claims] A processing chamber for performing a plasma processing on a wafer;
In a wafer processing apparatus comprising: means for generating the plasma in the processing chamber; and a wafer stage on which the wafer is loaded, wherein a refrigerant flow path provided in the wafer stage and through which a refrigerant flows, is connected to the refrigerant flow path. With a plurality of heat exchangers,
The wafer processing apparatus according to claim 1, wherein the temperature of the wafer is controlled by the plurality of heat exchangers. 2. A processing chamber for performing plasma processing on a wafer,
In a wafer processing apparatus provided with a means for generating the plasma in the processing chamber and a wafer stage for loading the wafer, a refrigerant flow path provided in the wafer stage and through which a refrigerant flows; A first heat exchanger having a container for storing a refrigerant, and a second heat exchanger connected in series with the first heat exchanger and disposed immediately before the refrigerant flows into the wafer stage. A wafer processing apparatus characterized by the above-mentioned. 3. A wafer processing apparatus comprising: a processing chamber; means for generating plasma in the processing chamber; and a wafer stage on which the wafer is mounted. A first heat exchanger having a container that stores the refrigerant and is connected to the refrigerant flow path; a thermoelectric element that is connected in series with the first heat exchanger and that is arranged to heat and cool the refrigerant. And a second heat exchanger having: 4. The wafer processing apparatus according to claim 1, wherein a pipe through which the refrigerant flows in the refrigerant channel is vacuum-insulated. 5. A wafer according to claim 1, wherein a plasma is applied to the wafer by introducing a cooling gas into the wafer stage at a position to be a back surface of the wafer. Processing equipment. 6. The wafer stage according to claim 1, wherein the wafer stage is made of a conductive material, a dielectric film provided on a surface of the wafer stage, the wafer stage and the wafer. Means for providing a potential difference between the dielectric film and the wafer, wherein the wafer is fixed by electrostatic force of charges stored between the dielectric film and the wafer. 7. A wafer manufacturing method for loading a wafer on a wafer stage and performing plasma processing on the wafer while controlling the temperature immediately before the coolant flows into the wafer stage, wherein the temperature control immediately before the cooling is performed by the wafer Alternatively, the wafer manufacturing method is controlled in accordance with a result of measuring the temperature of the wafer stage. 8. The wafer manufacturing method according to claim 7, wherein the immediately preceding temperature control is performed based on a procedure of a plasma processing performed on the wafer.