JP2012256608A - Target substance supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the temperature of a target substance in a target substance supply device supplying the target substance to a plasma generation chamber of an LPP type EUV light source device.SOLUTION: A target substance supply device includes: a liquefaction chamber 108 for cooling and liquefying a target substance supplied from the exterior; a nozzle 102 for ejecting the target substance liquefied in the liquefaction chamber 108; a rod 109 for controlling a temperature of the target substance in the liquefaction chamber 108; a cooler 110; a heater 111; a temperature sensor 112; a temperature control part 113; a rod 114 for controlling the temperature of the target substance in the nozzle 102; a cooler 115; a heater 116; a temperature sensor 117; and a temperature control part 118.

Description

  The present invention relates to a target material in a plasma generation chamber of an LPP (laser produced plasma) type extreme ultraviolet light source device that generates extreme ultra violet (EUV) light by irradiating the target material with a laser beam. The present invention relates to a target material supply device that supplies

  In recent years, along with the miniaturization of semiconductor processes, the miniaturization of optical lithography is rapidly progressing, and in the next generation, fine processing of 100 to 70 nm and further fine processing of 50 nm or less are required. Therefore, for example, in order to meet the demand for fine processing of 50 nm or less, it is expected to develop an exposure apparatus that combines an EUV light source having a wavelength of about 13 nm and a reduced projection reflective optics.

  As an EUV light source, an LPP (laser produced plasma) light source (hereinafter also referred to as an “LPP type EUV light source device”) using plasma generated by irradiating a target with a laser beam, and by discharge There are three types: a DPP (discharge produced plasma) light source using generated plasma and an SR (synchrotron radiation) light source using orbital radiation. Among these, since the LPP light source can considerably increase the plasma density, extremely high luminance close to that of black body radiation can be obtained, and light emission only in a necessary wavelength band is possible by selecting a target material. Because it is a point light source with a typical angular distribution, there is no structure such as an electrode around the light source, and it is possible to secure a very large collection solid angle of 2πsterad. It is considered to be a powerful light source for required EUV lithography.

  FIG. 6 is a view for explaining the principle of generation of LPP EUV light. The EUV light source device shown in FIG. 6 includes a laser oscillator 901, a condensing optical system 902 such as a condensing lens, a target supply device 903, a target nozzle 904, and an EUV condensing mirror 905. The laser oscillator 901 is a laser light source that pulsates a laser beam for exciting a target material. The condensing lens 902 condenses the laser beam emitted from the laser oscillator 901 at a predetermined position. The target supply device 903 supplies the target material to the target nozzle 904, and the target nozzle 904 jets the supplied target material to a predetermined position.

By irradiating the target material ejected from the target nozzle 904 with a laser beam, the target material is excited to generate plasma, and various wavelength components are emitted therefrom.
The EUV collector mirror 905 has a concave reflecting surface that reflects and collects light emitted from the plasma. In order to selectively reflect a predetermined wavelength component (for example, around 13.5 nm), for example, a film (Mo / Si multilayer film) in which molybdenum and silicon are alternately stacked is formed on the reflecting surface. . As a result, a predetermined wavelength component emitted from the plasma is output as output EUV light to an exposure apparatus or the like.

In the case where a gaseous substance such as xenon (Xe) is used as the target material at room temperature, a mechanism for liquefying the target material by pressurizing and cooling the target material may be provided on the upstream side of the target nozzle 904 (for example, , See Patent Document 1 below).
Patent Document 1 discloses a target supply system for supplying a liquid plasma target material, which includes a supply source for supplying a target material in a gas state and a heat exchanger for lowering the gas temperature for liquefaction. A supply system, an input end that receives liquid from the target supply system, an output end, and a narrow throat between them, a nozzle that discharges liquid droplets through the output end, and heats the liquid droplets to generate EUV radiation An LPP type EUV light source including a laser beam source for irradiating a liquid droplet with a laser beam is published.

  Further, by providing a piezo element in the target nozzle 904 and ejecting a liquid target material while vibrating the target nozzle 904, a droplet of the target material can be formed.

  On the other hand, the following Non-Patent Document 1 describes that when droplets of liquid argon or liquid oxygen are injected into a low-pressure gas from a nozzle, they are solidified in a jet state before being converted into droplets. This is presumably because the jet surface rapidly vaporizes due to a sudden drop in ambient pressure, and the jet freezes due to the latent heat of vaporization. Such solidification of the droplets is not preferable for obtaining stable EUV light. Therefore, conventionally, in the LPP type EUV light source device, solidification of droplets has been performed.

  FIG. 7 is a schematic diagram showing a conventional LPP type EUV light source device capable of preventing solidification of a jet and generating droplets. The LPP type EUV light source device shown in FIG. 7 includes a droplet generation chamber 910, a piezo driver 916, a plasma generation chamber 930 in which plasma is generated to generate EUV light, and a liquid of a target material in the plasma generation chamber 930. A laser light source 931 that generates laser light L2 for irradiating a droplet, a lens 932 that guides the laser light L2 emitted from the laser light source 931 to a laser light irradiation point 933, and a control unit 935 are included. The droplet generation chamber 910 and the plasma generation chamber 930 are connected through an opening 910 a provided in the droplet generation chamber 910.

  The droplet generation chamber 910 is provided with a nozzle 912 provided with a piezo element 913, a buffer gas introduction path 914 for introducing a buffer gas, and an exhaust pump 915. In addition, a piezo driver 916 that generates a drive signal supplied to the piezo element 913 is connected to the piezo element 913.

  On the upstream side of the nozzle 912, a liquefaction chamber 918 to which a target material (for example, Xe) is supplied from the outside via a target material introduction path 917 is disposed. A cooling end 919 a that is one end of a rod 919 for cooling the liquefying chamber 918 is connected to the liquefying chamber 918. The other end of the rod 919 is connected to a cooling device 920 (for example, a pulse tube refrigerator, liquid nitrogen, etc.). The rod 919 is provided with a heater 921 for finely adjusting the temperature of the rod 919. Further, the liquefaction chamber 918 is provided with a temperature sensor 922 (for example, a thermocouple), and the cooling device 920, the heater 921, and the temperature sensor 922 are connected to the temperature control unit 923. The temperature control unit 923 uses the temperature sensor 922 to monitor the temperature of the liquefaction chamber 918 and drives the cooling device 920 to cool the liquefaction chamber 918, thereby generating EUV light from the target material in the liquefaction chamber 918. Cool down to a temperature suitable for Further, the temperature control unit 923 can finely adjust the temperature of the target material in the liquefaction chamber 918 by appropriately driving the heater 921 and finely adjusting the temperature of the rod 919.

  The target material supplied from the outside is introduced into the liquefaction chamber 918 via the target material introduction path 917 and is cooled and liquefied in the liquefaction chamber 918 as indicated by the dotted line in the figure. The liquefied target material is ejected from the nozzle 912 into the droplet generation chamber 910.

  The piezo element 913 expands and contracts based on the drive signal supplied from the piezo driver 916, thereby giving the nozzle 912 vibration of a predetermined frequency f. Thus, by disturbing the flow (target jet) of the target material ejected from the nozzle 912 via the nozzle 912, the droplet 911 of the target material that is repeatedly dropped can be generated. That is, when the velocity of the target jet is v, the wavelength of vibration generated in the target jet is λ (λ = v / f), and the diameter of the target jet is d, for example, λ / d = 4. When satisfying 51), ideal droplets of uniform size are formed. The disturbance frequency f generated in the target jet is called the Rayleigh frequency. Actually, when λ / d = about 3 to 8, droplets of almost uniform size are formed. Since the velocity v of a target jet ejected from a nozzle generally used in an EUV light source apparatus is about 20 m / s to 30 m / s, it is given to the nozzle when forming a droplet having a diameter of about 10 μm to 100 μm. The power frequency is about several tens of kHz to several hundreds of kHz. Hereinafter, the number of droplets generated per second in this way is referred to as a droplet generation frequency or simply a generation frequency.

  The buffer gas introduction path 914 is provided for introducing an inert gas such as helium gas (He) or nitrogen gas (N 2) as a buffer gas. Here, when a substance that is in a gaseous state at normal temperature and pressure, such as xenon (Xe), is used as a liquid target, the target substance ejected from the nozzle is frozen in the high vacuum chamber as described above. In order to inhibit droplet formation, it must be avoided. Therefore, a buffer gas is introduced into the droplet generation chamber 910 so that the pressure near the nozzle 912 is equal to or higher than the saturated vapor pressure of the target material. Since this buffer gas is also introduced into the plasma generation chamber 930 through the opening 910a, it is desirable to use a gas that absorbs relatively little EUV light as described above.

  The exhaust pump 915 maintains the inside of the droplet generation chamber 910 at a desired degree of vacuum and discharges the evaporated gas evaporated from the surface of the generated droplet 911 to the outside.

  An exhaust pump 934 is provided in the plasma generation chamber 930. The exhaust pump 934 externally removes unnecessary substances such as evaporative gas evaporated from the surface of the droplet 911 introduced into the plasma generation chamber 930 through the opening 910 a and buffer gas leaked from the droplet generation chamber 910. The inside of the plasma generation chamber 930 is maintained at a desired degree of vacuum (for example, 1 Pa or less).

  The laser light L2 emitted from the laser light source 931 is collected by the lens 932, and irradiates the laser light irradiation point 933 in the plasma generation chamber 930 at a predetermined repetition operating frequency (for example, 10 kHz). In the plasma generation chamber 930, when the droplet 911 is irradiated with the laser beam L2 when passing through the laser beam irradiation point 933, the target material is turned into plasma and EUV light is emitted. The EUV light generated in this way is guided to an exposure apparatus or the like by, for example, a reflective optical system on which a Mo—Si film is formed.

  The control unit 935 controls the droplet generation frequency of the piezo driver 916 according to the diameter of the nozzle 912, the jetting speed of the target material, and the like.

US Pat. No. 6,324,256 (FIG. 3) Tanimoto, “Cryogenic Experimental Device for Production of Solid Pellets”, Proceedings of the 7th Symposium on Fusion Technology), 1972, p. 267-272

  In recent years, it has been found that in order to obtain stable EUV light, it is necessary to control the temperature of the droplet 911 within a relatively narrow temperature range. This is because if the target temperature at the time of ejecting the target material from the nozzle is high, the positional stability of the jet after ejection, and consequently the stability of the droplets, becomes unstable. Ideally, a temperature just above the freezing point where the target material does not freeze in the flow path is desirable. Conventionally, however, the temperature of the target material is controlled in the liquefaction chamber 918 as shown in FIG. Therefore, the temperature of the nozzle 912 located downstream of the liquefaction chamber 918 rises due to the influence of the buffer gas, and the temperature of the droplet 911 ejected from the nozzle 912 becomes higher than the temperature suitable for generating EUV light. The position and trajectory of the droplet 911 are not stable, and stable EUV light cannot be obtained.

  In order to prevent this, it is conceivable to control the temperature of the target material in the liquefaction chamber 918 to a lower limit temperature that does not freeze. However, even in such a case, since the target material exiting from the liquefaction chamber 918 passes through the nozzle 912, the temperature of the droplet 911 cannot be stabilized, and stable EUV light cannot be obtained. In addition, in order to set the temperature of the droplet 911 to a desired temperature, it is necessary to control the temperature of the target material in the liquefaction chamber 918 to a temperature just below the lower limit at which the target material does not freeze. As a result, the droplet 911 may not be ejected from the nozzle 912.

  Accordingly, in view of the above points, an object of the present invention is to stabilize the temperature of the target material supplied to the plasma generation chamber in the target material supply device that supplies the target material to the plasma generation chamber of the LPP type EUV light source device. And

  In order to solve the above-described problem, a target material supply device according to one aspect of the present invention is a target material supply device that supplies a target material to a plasma generation chamber of an extreme ultraviolet light source device of a laser-generated plasma method. A liquefaction chamber for cooling and liquefying the supplied target material, a nozzle for ejecting the liquefied target material in the liquefaction chamber, controlling the temperature of the target material in the liquefaction chamber, and the target material in the nozzle Temperature control means for controlling the temperature of the.

  According to the present invention, the temperature of the target material supplied to the plasma generation chamber can be stabilized. This makes it possible to obtain stable EUV light.

It is a schematic diagram which shows the structure of the EUV light source device using the target material supply apparatus which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the EUV light source device using the target material supply apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the structure of the EUV light source device using the target material supply apparatus which concerns on the 3rd Embodiment of this invention. It is a schematic diagram which shows the structure of the EUV light source device using the target material supply apparatus which concerns on the 4th Embodiment of this invention. It is a schematic diagram which shows the structure of the EUV light source device using the target material supply apparatus which concerns on the 5th Embodiment of this invention. It is a figure for demonstrating the EUV light production | generation principle of an LPP type EUV light source device. It is a schematic diagram which shows the structure of the conventional EUV light source device.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.
FIG. 1 is a schematic diagram showing a configuration of an LPP EUV light source apparatus using a target material supply apparatus according to the first embodiment of the present invention. This EUV light source apparatus includes a droplet generation chamber 100, a piezo driver 106, a plasma generation chamber 130 in which plasma generation for generating EUV light is performed, and a laser that irradiates a target material droplet in the plasma generation chamber 130. A laser light source 131 that generates light L 1, a lens 132 that guides the laser light L 1 emitted from the laser light source 131 to a laser light irradiation point 133, and a control unit 135 are included. The droplet generation chamber 100 and the plasma generation chamber 130 are connected through an opening 100 a provided in the droplet generation chamber 100.

  The droplet generation chamber 100 is provided with a nozzle 102 provided with a piezo element 103, a buffer gas introduction path 104 for introducing a buffer gas, and an exhaust pump 105. In addition, a piezo driver 106 that generates a drive signal supplied to the piezo element 103 is connected to the piezo element 103.

  A liquefaction chamber 108 to which a target material (for example, Xe) is supplied from the outside via a target material introduction path 107 is disposed on the upstream side of the nozzle 102. A cooling end 109 a that is one end of a rod 109 for cooling the liquefaction chamber 108 is connected to the liquefaction chamber 108. The other end of the rod 109 is connected to a cooling device 110 (for example, a pulse tube refrigerator, liquid nitrogen, etc.). The rod 109 is provided with a heater 111 for finely adjusting the temperature of the rod 109. Further, the liquefaction chamber 108 is provided with a temperature sensor 112 (for example, a thermocouple), and the cooling device 110, the heater 111, and the temperature sensor 112 are connected to the temperature control unit 113.

  The temperature controller 113 drives the cooling device 110 while monitoring the temperature of the liquefaction chamber 108 using the temperature sensor 112 to cool the liquefaction chamber 108, thereby generating EUV light from the target material in the liquefaction chamber 108. Cool down to a temperature suitable for Furthermore, the temperature control unit 113 can finely adjust the temperature of the target material in the liquefaction chamber 108 by appropriately driving the heater 111 and finely adjusting the temperature of the rod 109.

  The nozzle 102 is connected to a cooling end 114 a that is one end of a rod 114 for cooling the nozzle 102. The other end of the rod 114 is connected to a cooling device 115 (for example, a pulse tube refrigerator, liquid nitrogen, etc.). The rod 114 is provided with a heater 116 for finely adjusting the temperature of the rod 114. Further, the nozzle 102 is provided with a temperature sensor 117 (for example, a thermocouple), and the cooling device 115, the heater 116, and the temperature sensor 117 are connected to the temperature control unit 118.

  The temperature control unit 118 uses the temperature sensor 117 to monitor the temperature of the nozzle 102 and drives the cooling device 115 to cool the nozzle 102, thereby making the target material in the nozzle 102 suitable for generating EUV light. Cool to temperature. Furthermore, the temperature control unit 118 can finely adjust the temperature of the target material in the nozzle 102 by appropriately driving the heater 116 and finely adjusting the temperature of the rod 114.

  The target material supplied from the outside is introduced into the liquefaction chamber 108 through the target material introduction path 107 as shown by the dotted line in the figure, and is cooled and liquefied in the liquefaction chamber 108. The liquefied target material is injected into the droplet generation chamber 100 from the nozzle 102.

  The piezo element 103 gives a vibration of a predetermined frequency f to the nozzle 102 by expanding and contracting based on a drive signal supplied from the piezo driver 106. Thus, by disturbing the flow of the target material ejected from the nozzle 102 (target jet flow) via the nozzle 102, the droplet 101 of the target material that is repeatedly dropped can be generated. That is, when the velocity of the target jet is v, the wavelength of vibration generated in the target jet is λ (λ = v / f), and the diameter of the target jet is d, for example, λ / d = 4. When satisfying 51), ideal droplets of uniform size are formed. The disturbance frequency f generated in the target jet is called the Rayleigh frequency. Actually, when λ / d = about 3 to 8, droplets of almost uniform size are formed. Since the velocity v of a target jet ejected from a nozzle generally used in an EUV light source apparatus is about 20 m / s to 30 m / s, it is given to the nozzle when forming a droplet having a diameter of about 10 μm to 100 μm. The power frequency is about several tens of kHz to several hundreds of kHz. Hereinafter, the number of droplets generated per second in this way is referred to as a droplet generation frequency or simply a generation frequency.

  The buffer gas introduction path 104 is provided for introducing an inert gas such as helium gas (He) or nitrogen gas (N2) as a buffer gas. Here, when a substance that is in a gaseous state at normal temperature and pressure, such as xenon (Xe), is used as a liquid target, the target substance may be solidified as described above. must not. Therefore, a buffer gas is introduced into the droplet generation chamber 100 so that the pressure near the droplet is equal to or higher than the saturated vapor pressure of the target material. Since this buffer gas is also introduced into the plasma generation chamber 120 through the opening 100a, it is desirable to use a gas that absorbs relatively little EUV light as described above.

  The exhaust pump 105 maintains the inside of the droplet generation chamber 100 at a desired degree of vacuum and discharges the evaporated gas evaporated from the surface of the generated droplet 101 to the outside.

  An exhaust pump 134 is provided in the plasma generation chamber 130. The exhaust pump 134 removes unnecessary substances such as evaporative gas evaporated from the surface of the droplet 101 introduced into the plasma generation chamber 130 through the opening 100a and buffer gas leaked from the droplet generation chamber 100 from the outside. As a result, the plasma generation chamber 130 is maintained at a desired degree of vacuum (for example, 1 Pa or less).

The laser light L1 emitted from the laser light source 131 is collected by the lens 132 and irradiates the laser light irradiation point 133 in the plasma generation chamber 130 at a predetermined repetition operating frequency (for example, 10 kHz). In such a plasma generation chamber 130, when the droplet 101 is irradiated with the laser beam L1 when passing through the laser beam irradiation point 133, the target material is turned into plasma and EUV light is emitted. The EUV light generated in this way is guided to an exposure apparatus or the like by, for example, a reflective optical system on which a Mo—Si film is formed.
The control unit 135 controls the droplet generation frequency of the piezo driver 106 according to the diameter of the nozzle 102, the injection speed of the target material, and the like.

  As described above, according to the present embodiment, by using the rod 114, the cooling device 115, the temperature sensor 117, and the temperature control unit 118, the temperature of the target material in the nozzle 102 is decreased by cooling the nozzle 102. Can be controlled. Thereby, the temperature of the droplet 101 ejected from the nozzle 102 can be stabilized, and stable EUV light can be obtained. Further, by further using the heater 116, the temperature of the nozzle 102 can be finely adjusted, and the temperature of the target material in the nozzle 102 can be finely adjusted.

  In this embodiment, the temperature of the target material in the nozzle 102 is controlled by using a set of rods 114, a cooling device 115, a heater 116, a temperature sensor 117, and a temperature control unit 118. However, the temperature of the target material in the nozzle 102 may be controlled by using two or more sets of rods, a cooling device, a heater, a temperature sensor, and a temperature control unit. By doing so, it is possible to control the temperature of the target material in the nozzle 102 with higher accuracy.

Next, a second embodiment of the present invention will be described.
FIG. 2 is a schematic diagram showing a configuration of an LPP EUV light source apparatus using a target material supply apparatus according to the second embodiment of the present invention.

  In the present embodiment, a rod 119 having two cooling ends is included instead of the rods 109 and 114 in the first embodiment described above. A first cooling end 119 a of the rod 119 is connected to the liquefaction chamber 108, and a second cooling end 119 b of the rod 119 is connected to the nozzle 102. The third end of the rod 119 is connected to the cooling device 110. A heater 111 is provided in the vicinity of the cooling end 119a of the rod 119, and a heater 116 is provided in the vicinity of the cooling end 119b of the rod 119.

The cooling device 110, the heaters 111 and 116, and the temperature sensors 112 and 117 are connected to the temperature control unit 120.
The temperature controller 120 drives the cooling device 110 while monitoring the temperatures of the liquefaction chamber 108 and the nozzle 102 using the temperature sensors 112 and 117, thereby cooling the liquefaction chamber 108 and the nozzle 102. The target material in the nozzle 102 is cooled. Further, the temperature control unit 120 can finely adjust the temperature of the target material in the liquefaction chamber 108 by finely adjusting the temperature of the cooling end 119a of the rod 109 by appropriately driving the heater 111. Further, the temperature control unit 120 drives the heater 116 appropriately to finely adjust the temperature of the cooling end 119b of the rod 109 separately from the temperature of the cooling end 119a, thereby finely adjusting the temperature of the target material in the nozzle 102. Can be adjusted.

  Thus, according to this embodiment, the target material in the liquefaction chamber 108 can be cooled and liquefied by using the rod 119, the cooling device 110, the temperature sensors 112 and 117, and the temperature control unit 120. The temperature of the target material in the nozzle 102 can be controlled. Thereby, the temperature of the droplet 101 ejected from the nozzle 102 can be stabilized, and stable EUV light can be obtained.

  In this embodiment, the rod 119 having two cooling ends is used, but a rod having three or more cooling ends may be used. When such a rod is used, one cooling end may be connected to the liquefaction chamber 108 and the other cooling end may be connected to the nozzle 102. By doing so, it is possible to control the temperature of the target material in the nozzle 102 with higher accuracy.

Next, a third embodiment of the present invention will be described.
FIG. 3 is a schematic diagram showing the configuration of an LPP EUV light source apparatus using a target material supply apparatus according to the third embodiment of the present invention.

  In the present embodiment, a rod 121 is included instead of the rod 114 in the first embodiment described above. The cooling end 121 a of the rod 121 is connected to the droplet generation chamber 100, and the other end of the rod 121 is connected to the cooling device 115. A heater 116 is provided in the vicinity of the cooling end 121 a of the rod 121.

  Further, in the first embodiment described above, the temperature sensor 117 is provided in the nozzle 102, but in this embodiment, the temperature sensor 117 is provided in the droplet generation chamber 100.

  The temperature controller 118 drives the cooling device 115 while monitoring the temperature of the droplet generation chamber 100 using the temperature sensor 117, and cools the buffer gas in the droplet generation chamber 100. By cooling the buffer gas in this way, the nozzle 102 is cooled, and the target material in the nozzle 102 is cooled. Furthermore, the temperature control unit 118 can finely adjust the temperature of the buffer gas in the droplet generation chamber 100 by appropriately driving the heater 116. Thus, the temperature of the nozzle 102 is finely adjusted by finely adjusting the temperature of the buffer gas. By finely adjusting the temperature of the nozzle 102 in this way, the temperature of the target material in the nozzle 102 is finely adjusted.

  As described above, according to the present embodiment, the temperature of the buffer gas in the droplet generation chamber 100 can be controlled by using the cooling device 115, the temperature sensor 117, the temperature control unit 118, and the rod 121. . By controlling the temperature of the buffer gas in this way, the temperature of the target material in the nozzle 102 can be stabilized via the nozzle 102, and stable EUV light can be obtained.

In the first embodiment described above, the cooling end 114a of the rod 114 and the temperature sensor 117 are connected to the nozzle 102 (see FIG. 1), and the opening for passing the rod 114 and the temperature sensor 117 are connected. It was necessary to provide the droplet generation chamber 100 with an opening for passing the wiring to be connected.
On the other hand, in the present embodiment, the cooling end 121 a of the rod 121 and the temperature sensor 117 are connected to the droplet generation chamber 100. Therefore, it is not necessary to provide an opening for passing the rod 121 and an opening for passing the wiring connected to the temperature sensor 117 in the droplet generation chamber 100, and the droplet generation chamber 100 can be simplified.

  In this embodiment, the two rods 109 and 121 are used. However, a rod having two cooling ends may be used like the rod 119 in the second embodiment described above. . When such a rod is used, one cooling end may be connected to the liquefaction chamber 108 and the other cooling end may be connected to the droplet generation chamber 100.

Next, a fourth embodiment of the present invention will be described.
FIG. 4 is a schematic diagram showing a configuration of an LPP EUV light source apparatus using a target material supply apparatus according to the fourth embodiment of the present invention.

  In the third embodiment described above, the temperature sensor 117 is provided in the droplet generation chamber 100 (see FIG. 3). On the other hand, in the present embodiment, the temperature sensor 117 is provided in the nozzle 102. Therefore, the temperature control unit 118 can cool the buffer gas in the droplet generation chamber 100 by driving the cooling device 115 while monitoring the temperature of the nozzle 102 using the temperature sensor 117. The temperature control unit 118 can finely adjust the temperature of the rod 121 and finely adjust the temperature of the buffer gas in the droplet generation chamber 100 by appropriately driving the heater 116. Thereby, the temperature of the target material in the nozzle 102 can be finely adjusted via the nozzle 102. By directly monitoring the temperature of the nozzle 102, it is possible to adjust the temperature more accurately than in the third embodiment.

  As described above, according to this embodiment, the temperature of the target material in the nozzle 102 can be stabilized with high accuracy by controlling the temperature of the buffer gas in the droplet generation chamber 100, and stable EUV light can be obtained. It is possible to obtain

Next, a fifth embodiment of the present invention will be described.
FIG. 5 is a schematic diagram showing a configuration of an LPP EUV light source device using a target material supply device according to a fifth embodiment of the present invention.

  In the present embodiment, instead of the cooling device 115, the heater 116, the temperature sensor 117, the temperature control unit 118, and the rod 121 in the third and fourth embodiments described above, a rod 122, a cooling device 123, A heater 124, a temperature sensor 125, and a temperature control unit 126 are included.

  The cooling end 122 a of the rod 122 is connected to the buffer gas introduction path 104, and the other end of the rod 122 is connected to the cooling device 123. A heater 124 is provided in the vicinity of the cooling end 122 a of the rod 122. Further, a temperature sensor 125 is provided in the buffer gas introduction path 104, and the cooling device 123, the heater 124, and the temperature sensor 125 are connected to the temperature control unit 126.

  The temperature controller 126 can cool the buffer gas in the buffer gas introduction path 104 by driving the cooling device 123 while monitoring the temperature of the buffer gas introduction path 104 using the temperature sensor 125. Further, the temperature control unit 126 can finely adjust the temperature of the buffer gas in the buffer gas introduction path 104 by finely adjusting the temperature of the rod 122 by appropriately driving the heater 124.

  Thus, according to this embodiment, the temperature of the buffer gas in the buffer gas introduction path 104 is controlled by using the rod 122, the cooling device 123, the heater 124, the temperature sensor 125, and the temperature control unit 126. Thus, the temperature of the target material in the nozzle 102 can be controlled to be stable, and stable EUV light can be obtained.

  In the third and fourth embodiments described above, the cooling end 121a of the rod 121 is connected to the droplet generation chamber 100 (see FIGS. 3 and 4). On the other hand, in the present embodiment, the cooling end 122 a of the rod 122 is connected to the buffer gas introduction path 104. Thus, in this embodiment, since the buffer gas can be cooled in the buffer gas introduction path 104, the cooling efficiency of the nozzle can be improved as compared with the third and fourth embodiments described above. .

Although the temperature sensor 125 is provided in the buffer gas introduction path 104 here, the temperature sensor 125 may be provided in the nozzle 102.
In this embodiment, the cooling device 115, the heater 116, the temperature sensor 117, the temperature control unit 118, and the rod 121 (see FIGS. 3 and 4) in the third and fourth embodiments may be further included. good.

  The present invention can be used in a target material supply device that supplies a target material to a plasma generation chamber of an LPP type EUV light source device used in an exposure apparatus or the like.

  100, 910 ... Droplet generation chamber, 101, 911 ... Droplet, 102, 912 ... Nozzle, 103, 913 ... Piezo element, 104, 914 ... Buffer gas introduction path, 105, 134, 915, 934 ... Exhaust pump, 106 , 916 ... Piezo driver, 107, 917 ... Target material introduction path, 108, 918 ... Liquefaction chamber, 109, 114, 119, 121, 122, 919 ... Rod, 110, 115, 920 ... Cooling device, 111, 116, 124 , 921 ... Heater, 112, 117, 125, 922 ... Temperature sensor, 113, 118, 120, 126, 923 ... Temperature controller, 130, 930 ... Plasma generation chamber, 131, 931 ... Laser light source, 132, 932 ... Lens 133, 933... Laser beam irradiation point, 135, 935... Controller, 901. 2 ... condenser lens, 903 ... target supply unit, 904 ... target nozzle, 905 ... EUV collector mirror

In order to solve the above-described problem, a target material supply device according to one aspect of the present invention is a target material supply device that supplies a target material to a plasma generation chamber of an extreme ultraviolet light source device of a laser-generated plasma method. A liquefaction chamber for liquefying the supplied target material; a first temperature control device for controlling the temperature of the target material in the liquefaction chamber; and a nozzle having an opening for ejecting the liquefied target material in the liquefaction chamber; And a second temperature control device for controlling the temperature of the target material in the nozzle .

Claims (7)

A target material supply device for supplying a target material to a plasma generation chamber of a laser-generated plasma type extreme ultraviolet light source device,
A liquefaction chamber for cooling and liquefying the target material supplied from outside;
A nozzle for ejecting the target material liquefied in the liquefaction chamber;
A temperature control means for controlling the temperature of the target material in the liquefaction chamber, and for controlling the temperature of the target material in the nozzle;
A target material supply apparatus comprising: The temperature control means includes first and second temperature control devices;
The first temperature control device comprises:
A first heat conducting member having one end connected to the liquefaction chamber;
A first cooling device connected to the other end of the first heat conducting member for cooling the first heat conducting member;
A first temperature sensor provided in the liquefaction chamber;
A first control unit for controlling the temperature of the target material in the liquefaction chamber by driving the first cooling device while monitoring the temperature of the liquefaction chamber using the first temperature sensor;
Have
The second temperature control device comprises:
A second heat conducting member having one end connected to the nozzle;
A second cooling device connected to the other end of the second heat conducting member for cooling the second heat conducting member;
A second temperature sensor provided in the nozzle;
A second control unit for controlling the temperature of the target material in the nozzle by driving the second cooling device while monitoring the temperature of the nozzle using the second temperature sensor;
The target material supply apparatus according to claim 1, comprising: The temperature control means is
A heat conducting member having a first end connected to the liquefaction chamber and a second end connected to the nozzle;
A cooling device connected to the third end of the heat conducting member for cooling the heat conducting member;
A first temperature sensor provided in the liquefaction chamber;
A second temperature sensor provided in the nozzle;
For controlling the temperature of the target material in the liquefaction chamber and the nozzle by driving the cooling device while monitoring the temperature of the liquefaction chamber and the nozzle using the first and second temperature sensors. A control unit;
The target material supply apparatus according to claim 1, comprising: The temperature control means further comprises first and second temperature fine adjustment devices for finely adjusting the temperatures of the first and second ends of the heat conducting member, respectively;
The controller finely adjusts the temperature of the target material in the liquefaction chamber by driving the first temperature fine adjustment device, and drives the second temperature fine adjustment device to drive the inside of the nozzle. The target material supply device according to claim 3, wherein the target material temperature is finely adjusted. A buffer gas for preventing the target material ejected from the nozzle from being solidified is filled, and has an opening through which the target material ejected from the nozzle can pass, and is connected to the plasma generation chamber through the opening. Further comprising a buffer gas chamber,
The temperature control means includes first and second temperature control devices;
The first temperature control device comprises:
A first heat conducting member having one end connected to the liquefaction chamber;
A first cooling device connected to the other end of the first heat conducting member for cooling the first heat conducting member;
A first temperature sensor provided in the liquefaction chamber;
A first control unit for controlling the temperature of the target material in the liquefaction chamber by driving the first cooling device while monitoring the temperature of the liquefaction chamber using the first temperature sensor;
Have
The second temperature control device comprises:
A second heat conducting member having one end connected to the buffer gas chamber;
A second cooling device connected to the other end of the second heat conducting member for cooling the second heat conducting member;
A second temperature sensor provided in the nozzle or the buffer gas chamber;
A second temperature controller for controlling the temperature of the target material in the nozzle by driving the second cooling device while monitoring the temperature of the nozzle or the buffer gas chamber using the second temperature sensor. A control unit;
The target material supply apparatus according to claim 1, comprising: The target material ejected from the nozzle is filled with a buffer gas for preventing freezing, and has an opening through which the target material ejected from the nozzle can pass, and is connected to the plasma generation chamber through the opening. Further comprising a buffer gas chamber,
The temperature control means includes first and second temperature control devices;
The first temperature control device comprises:
A first heat conducting member having one end connected to the liquefaction chamber;
A first cooling device connected to the other end of the first heat conducting member for cooling the first heat conducting member;
A first temperature sensor provided in the liquefaction chamber;
A first control unit for controlling the temperature of the target material in the liquefaction chamber by driving the first cooling device while monitoring the temperature of the liquefaction chamber using the first temperature sensor;
Have
The second temperature control device comprises:
A second heat conducting member having one end connected to a buffer gas introduction path for introducing buffer gas into the buffer gas chamber;
A second cooling device connected to the other end of the second heat conducting member for cooling the second heat conducting member;
A second temperature sensor provided in the nozzle or the buffer gas introduction path;
A second for controlling the temperature of the target material in the nozzle by driving the second cooling device while monitoring the temperature of the nozzle or the buffer gas introduction path using the second temperature sensor. A control unit of
The target material supply apparatus according to claim 1, comprising:   The target material supply apparatus according to any one of claims 1 to 6, further comprising means for applying a vibration having a predetermined frequency to the target material ejected from the nozzle.