JP3958049B2 - Reticle with pellicle, device manufacturing related apparatus, exposure apparatus and device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionReticle with pellicle,Device manufacturing related equipment, Exposure apparatus andThe present invention relates to a device manufacturing method.
[0002]
[Prior art]
In a manufacturing process of a semiconductor element formed from an ultrafine pattern such as LSI or VLSI, a reduction type projection exposure apparatus that forms and burns a circuit pattern drawn on a mask onto a substrate coated with a photosensitive agent. in use. As the mounting density of semiconductor elements has increased, further refinement of the pattern line width has been demanded, and the resolution has been improved in response to the development of the resist process and the miniaturization of the exposure apparatus.
[0003]
As means for improving the resolution of the exposure apparatus, there are a method of changing the exposure wavelength to a shorter wavelength and a method of increasing the numerical aperture (NA) of the projection optical system.
[0004]
With regard to the exposure wavelength, the i-line at 365 nm has recently shifted to a KrF excimer laser having an oscillation wavelength near 248 nm and an ArF excimer laser having an oscillation wavelength near 193 nm. Furthermore, recently, fluorine (F) having an oscillation wavelength near 157 nm.₂) Excimer laser is being developed.
[0005]
Far ultraviolet rays, particularly ArF excimer lasers having a wavelength near 193 nm, and fluorine (F₂In the excimer laser, oxygen (O₂It is known that there are multiple absorption bands.
[0006]
For example, a wavelength of 157 nm of a fluorine excimer laser generally corresponds to a wavelength region called vacuum ultraviolet. In this wavelength region, light absorption by oxygen molecules is large, so that almost no light is transmitted in the atmosphere, and light can be transmitted only in an environment where the pressure is lowered to near vacuum and the oxygen concentration is sufficiently reduced. According to the document “Photochemistry of Small Molecules” (Hideo Okabe, AWiley-Interscience Publication, 1978, p. 178), the absorption coefficient of oxygen for light at a wavelength of 157 nm is about 190 atm.^-1cm^-1It is. This means that when light with a wavelength of 157 nm passes through a gas with an oxygen concentration of 1% at 1 atmosphere, the transmittance per cm is
T = exp (−190 × 1 cm × 0.01 atm) = 0.150
There is only.
[0007]
In addition, oxygen (O₃), And this ozone further increases light absorption and significantly reduces the transmittance. Furthermore, it is also known that various products resulting from the photochemical reaction of the laser adhere to the surface of the optical element, thereby reducing the light transmittance of the optical system.
[0008]
When the amount of light decreases, the time required for exposure becomes longer and the productivity decreases.
[0009]
Therefore, in order to ensure sufficient productivity, ArF excimer laser, fluorine (F₂) In the optical path of the exposure optical system of a projection exposure apparatus that uses far ultraviolet rays such as an excimer laser, the oxygen concentration in the optical path is lowered to a low level of several ppm order or less by a purge mechanism using an inert gas such as nitrogen. A way to suppress it is taken.
[0010]
In addition, a load lock mechanism is provided at a portion connecting the inside of the exposure apparatus to the outside, and when a reticle or wafer is carried into the exposure apparatus from the outside, the load lock mechanism is temporarily shut off from the outside air. The impurities were purged with an inert gas and then carried into the exposure apparatus.
[0011]
FIG. 1 shows fluorine (F₂FIG. 2 is a schematic cross-sectional view showing an example of a semiconductor exposure apparatus using an excimer laser as a light source and having a load lock mechanism.
[0012]
In FIG. 1, 1 is a reticle stage on which a reticle on which a pattern is drawn is mounted, 2 is a projection optical system for projecting a pattern on the reticle as an original onto a wafer as a photosensitive substrate, and 3 is an X, Y, A wafer stage driven in the Z, θ and tilt directions, 4 is an illumination optical system for irradiating illumination light onto the reticle, 5 is a drawing optical system for guiding light from the light source to the illumination optical system 4, and 6 is a light source. Fluorine (F₂) Excimer laser, 7 is a masking blade for shielding exposure light so that only the pattern area on the reticle is illuminated, 8 and 9 are housings for covering the exposure optical axes around the reticle stage 1 and the wafer stage 3, respectively. He air conditioners 11 and 12 that adjust the interiors of the projection optical system 2 and the illumination optical system 4 to a predetermined He atmosphere,₂N to adjust to atmosphere₂Air conditioners 13 and 14 are reticle load locks and wafer load locks used when carrying reticles and wafers into housings 8 and 9, respectively. Reference numerals 15 and 16 are reticle hands and wafer hands for carrying reticles and wafers, respectively. , 17 is a reticle alignment mark used to adjust the position of the reticle, 18 is a reticle storage for storing a plurality of reticles in the housing 8, and 19 is a pre-alignment unit for pre-aligning the wafer. Further, the entire apparatus is housed in an environmental chamber (not shown) as necessary, and the temperature in the chamber is controlled to be constant by circulating air controlled to a predetermined temperature in the environmental chamber.
[0013]
In general, a reticle is provided with a pattern protection device called a pellicle. This prevents foreign matter such as dust from adhering to the reticle pattern surface, thereby suppressing the frequency of occurrence of defects due to foreign matter transfer onto the wafer.
[0014]
FIG. 2 is a schematic diagram showing the structure of a reticle with a pellicle. The pellicle 21 is attached to the pattern surface side of the reticle 20 using an adhesive or the like. The pellicle 21 includes a frame 22 having a size that surrounds the reticle pattern, and a pellicle film 23 that transmits exposure light attached to one end surface of the frame 22. In addition, if the space surrounded by the pellicle 21 and the reticle 20 (hereinafter referred to as the pellicle space) is completely sealed, a pellicle film may be inflated or dented due to a pressure difference or an oxygen concentration difference inside and outside the pellicle space. 22 is provided with a vent hole 24 so that gas can flow inside and outside the pellicle space. Further, a dust filter (not shown) is provided in the ventilation path in order to prevent external foreign matter from entering the pellicle space from the ventilation hole 24.
[0015]
FIG. 3 is a schematic diagram showing an example of a reticle transport path in the exposure apparatus shown in FIG.
[0016]
In FIG. 3, reference numeral 25 denotes a foreign substance inspection apparatus that measures the size and number of foreign substances such as dust adhering to the reticle surface and pellicle film surface. The reticle 20 is carried into a reticle load lock 13 serving as an entrance of the exposure apparatus manually or by a transport device (not shown). At this time, since the reticle and the pellicle are generally stuck outside the exposure apparatus, the pellicle 21 is already stuck on the reticle 20 to be carried. Next, the inside of the reticle load lock 13 is purged with an inert gas, and after an inert gas atmosphere equivalent to that of the housing 8 is obtained, the reticle hand 15 is used to either the reticle stage 1 or the reticle storage 18 or the foreign matter inspection device 25. The reticle 20 is conveyed.
[0017]
[Problems to be solved by the invention]
As described above, ultraviolet rays, particularly ArF excimer laser light and fluorine (F₂) In an exposure apparatus using an excimer laser beam as a light source, the absorption of exposure light by oxygen and moisture is large. Therefore, in order to obtain sufficient transmittance and stability, the oxygen and moisture concentrations in the optical path are reduced. In order to maintain the density, a load lock mechanism is provided in a portion connecting the inside and outside of the exposure apparatus. When a reticle or wafer is loaded from the outside, the load lock mechanism is temporarily shut off from the outside air. The impurities were purged with an inert gas and then carried into the exposure apparatus.
[0018]
However, a pellicle is affixed to the reticle carried into the load lock chamber, and the pellicle space is structured so that it can communicate with the outside air only through a relatively small ventilation hole. Even after reaching the gas concentration, it took a longer time to complete the replacement in the pellicle space, which was a factor that deteriorated productivity.
[0019]
Regarding such a problem, Japanese Patent Application Laid-Open No. 9-73167 discloses an invention in which a reticle and a pellicle are pasted together in an inert gas atmosphere, and the inside of the pellicle space is sealed with an inert gas having a concentration of 1% or less. Yes. However, as described above, the transmittance of light having a wavelength of 157 nm is only about 15% per 1 cm in an atmospheric gas having an oxygen concentration of 1%. At present, the air gap between the reticle and the pellicle film is about 6 mm. Even if this space is filled with a gas having an oxygen concentration of 0.1%, the transmittance of light having a wavelength of 157 nm in this space is as follows. Only 89.2%. On the other hand, the total spatial distance of the optical path from the light source of the exposure apparatus to the wafer exceeds at least 1 m. In order to secure 80% or more as the transmittance of a 1 m space, it is necessary to suppress the oxygen concentration to about 10 ppm or less in the entire optical path. Ideally, the target oxygen concentration is 1 ppm or less. An oxygen concentration of at least 1 to 100 ppm or less is also required for the pellicle space from the viewpoint of balance with other spaces and maintaining transmittance at the total space distance. Of course, the same applies to the moisture and carbon dioxide concentration.
[0020]
Moreover, the time required to replace the inert gas in the pellicle space when exchanging the reticle increases the standby time of the entire apparatus, which affects productivity. Therefore, it is desirable to replace the pellicle space with an inert gas in as short a time as possible. Further, due to the function of the pellicle, dust cannot be allowed to flow into the pellicle space during gas replacement. Japanese Patent Application Laid-Open No. 2001-133960 proposes that after the pellicle is attached, the inside of the pellicle space is replaced with an inert gas using the gas inlet and outlet holes provided in the pellicle frame. However, the method disclosed in Japanese Patent Application Laid-Open No. 2001-133960 has a drawback that the replacement time becomes longer due to the occurrence of stagnation in which the gas does not flow easily in the vicinity of the inflow hole or in the corner of the pellicle space.
[0021]
  The present invention has been made in view of the above background. For example,Surrounded by reticle, pellicle and pellicle frameReduce the non-uniformity and stagnation of the inert gas flow in the space,Replace the gas in the space with an inert gasThe purpose is to shorten the time.
[0022]
[Means for Solving the Problems]
  The first aspect of the present invention is:A reticle with a pellicle including a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle, wherein the pellicle frame includes first and second pellicle frame pieces facing each other The first and second pellicle frame pieces are each made of a porous material, and the reticle with the pellicle is arranged on the outside of the first pellicle frame piece, has a first opening, and the pellicle A first manifold having an inner width equal to an inner width of the frame, and an inert gas is supplied through the first opening, whereby the first pellicle frame piece and the first pellicle frame The space surrounded by the manifold is maintained at positive pressure,It is characterized by that.
[0023]
  According to a preferred embodiment of the present invention,A second manifold disposed outside the second pellicle frame piece, having a second opening, and having an inner width equal to the inner width of the pellicle frame; As a result of the gas being discharged, the space surrounded by the second pellicle frame piece and the second manifold is maintained at a negative pressure.It is preferable.
[0024]
  According to a second aspect of the present invention, there is provided a device manufacturing related apparatus, a support means for supporting a reticle with a pellicle, which includes a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle. Supply means for supplying an inert gas into a space surrounded by the reticle, the pellicle and the pellicle frame of the reticle with the pellicle supported by the support means, and the pellicle frames are mutually connected The first and second pellicle frame pieces are opposed to each other, each of the first and second pellicle frame pieces is made of a porous material, and the reticle with the pellicle is disposed outside the first pellicle frame piece. And a first manifold having a first opening and an inner width equal to the inner width of the pellicle frame, wherein an inert gas is supplied through the first opening. Thus, the space surrounded by the first pellicle frame piece and the first manifold is maintained at a positive pressure, and the supply means passes through the first opening and the reticle and the first manifold. An inert gas is supplied into a space surrounded by the pellicle and the pellicle frame.
[0025]
  According to a preferred embodiment of the present invention,The apparatus further includes discharge means for discharging gas from the space surrounded by the reticle, the pellicle, and the pellicle frame, and the reticle with the pellicle is disposed outside the second pellicle frame piece, The second pellicle frame piece has an opening and a second manifold having an inner width equal to the inner width of the pellicle frame, and gas is discharged through the second opening. And the space surrounded by the second manifold is maintained at a negative pressure, and the discharge means is surrounded by the reticle, the pellicle, and the pellicle frame through the second opening. Exhaust gas from inside the space,It is preferable.
[0026]
  According to a preferred embodiment of the present invention,It can be configured as any one of a storage for storing a reticle with a pellicle, an inspection apparatus for inspecting a reticle with a pellicle, and a transport box for transporting a reticle with a pellicle.
[0027]
  A third aspect of the present invention is an exposure apparatus that exposes a substrate through a reticle with a pellicle, and includes a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle A support means for supporting the reticle; and a supply means for supplying an inert gas into a space surrounded by the reticle, the pellicle and the pellicle frame of the reticle with the pellicle supported by the support means. The pellicle frame includes first and second pellicle frame pieces facing each other, each of the first and second pellicle frame pieces is made of a porous material, and the reticle with the pellicle includes the first pellicle frame piece. And a first manifold having a first opening and having an inner width equal to the inner width of the pellicle frame, the first manifold being disposed outside the pellicle frame piece, By supplying the inert gas, the space surrounded by the first pellicle frame piece and the first manifold is maintained at a positive pressure, and the supply means includes the first opening. An inert gas is supplied into a space surrounded by the reticle, the pellicle, and the pellicle frame through
[0028]
  According to a preferred embodiment of the present invention,The apparatus further includes discharge means for discharging gas from the space surrounded by the reticle, the pellicle, and the pellicle frame, and the reticle with the pellicle is disposed outside the second pellicle frame piece, The second pellicle frame piece has an opening and a second manifold having an inner width equal to the inner width of the pellicle frame, and gas is discharged through the second opening. And the space surrounded by the second manifold is maintained at a negative pressure, and the discharge means is surrounded by the reticle, the pellicle, and the pellicle frame through the second opening. Exhaust gas from inside the space,It is preferable.
[0029]
  According to a fourth aspect of the present invention, there is provided a device manufacturing method, comprising: exposing a substrate through a reticle with a pellicle using the exposure apparatus described above; and developing the exposed substrate. And
[0037]
DETAILED DESCRIPTION OF THE INVENTION
An exposure apparatus according to a preferred embodiment of the present invention uses, for example, ultraviolet light as exposure light, replaces the inside of the exposure apparatus with an inert gas, and projects a mask pattern onto a photosensitive substrate through a projection optical system. Relates to the device. Examples of the ultraviolet light as the exposure light include deep ultraviolet light, particularly ArF excimer laser light having a wavelength of about 193 nm, and fluorine (F₂Excimer laser light or the like is suitable.
[0038]
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0039]
[First Embodiment]
4 to 6 are diagrams showing a schematic configuration of the purge mechanism (gas replacement device) according to the first embodiment of the present invention. This purge mechanism is a mechanism for purging the pellicle space with an inert gas, and can be applied to any exposure apparatus that uses a reticle with a pellicle, for example, a reticle storage (reticle stocker), a reticle inspection apparatus, a reticle. It can also be applied to a transport box or the like. That is, the present invention can be applied to various device manufacturing related apparatuses that use, handle, or inspect a reticle with a pellicle.
[0040]
The airtight chamber 26 shown in FIGS. 4 to 6 can correspond to, for example, the housing 8 that stores the reticle stage 1 and the reticle storage 18 in FIG. 1 or the reticle load lock 13. An inert gas is introduced through the inert gas supply port 27, and the inert gas is discharged through the inert gas discharge port 28, whereby the inside of the hermetic chamber 26 is purged (replaced) with the inert gas.
[0041]
The reticle support base 29 is arranged in the reticle transport path in the housing 8 of FIG. 1, and the reticle 20 to which the pellicle 21 is attached is a reticle hand (for example, 15 in FIG. 3) or an airtight chamber 26. It is placed while being positioned at a predetermined position on the support base 29 by a transfer robot (not shown) provided manually or manually. The support base 29 may be provided with a suction groove for sucking and fixing the reticle as required.
[0042]
In this embodiment, the pellicle frame 30 includes four pellicle frame pieces 30a to 30d. The pellicle frame pieces 30a and 30b are made of a porous material (for example, graphite or selephite), and the pellicle frame pieces 30c and 30d are made of a non-porous material. 4 to 6, the pellicle frame piece 30a is used as a gas supply side (gas inflow portion), and the pellicle frame piece 30b is used as a gas discharge side (gas outflow portion), and they are arranged at opposing positions (sides). Has been. Manifolds 31a and 31b are attached to the pellicle frame pieces 30a and 30b, respectively. The width of the space in the manifolds 31a and 31b (the vertical width in FIG. 6) is preferably substantially the same as the width in the pellicle space 100 (the vertical width in FIG. 6). Thereby, the stagnation of the flow of gas can be reduced effectively.
[0043]
In the vicinity of the manifold 31a, an inert gas supply joint 33a is provided to supply an inert gas into a pellicle space (a space defined by the reticle 20, the pellicle frame 30, and the pellicle film 21) 100 as a gas replacement space. In addition, an inert gas discharge joint 33b is provided in the vicinity of the manifold 31b to discharge gas from the pellicle space 100. The drive mechanisms 34a and 34b move the inert gas discharge joints 33a and 33b closer to or away from the manifolds 31a and 31b. In order to ensure a tightness, that is, in order to prevent inflow and outflow of gas through the contact portion between the manifolds 31a and 31b and the inert gas discharge joints 33a and 33b, the manifolds 31a and 31b have O-rings 32 respectively. Is provided.
[0044]
FIG. 5 schematically shows a state in which the inert gas is allowed to flow into the pellicle space 100 with the inert gas supply joint 33a and the inert gas recovery joint 33b in close contact with the manifolds 31a and 31b by the drive mechanisms 34a and 34b, respectively. FIG.
[0045]
FIG. 6 is a view of FIG. 5 as viewed from below, and shows the positional relationship between the reticle 20, the pellicle frame pieces 30a to 30d, the gas supply joint 33a, and the gas discharge joint 33b.
[0046]
In FIG. 6, pellicle frame pieces 30a and 30b made of a porous material are provided on the left and right sides of the pellicle frame, and gas is supplied to the manifolds 31a and 31b and the manifold 31a for pressurizing and depressurizing the pellicle space 100. An inert gas supply joint 33a for discharging gas and an inert gas discharge joint 33b for discharging gas from the manifold 31b are provided. The inert gas supply joint 33a communicates with a path 35a for supplying an inert gas, and a positive pressure regulator 36a for adjusting the inside of the manifold 31a to a desired positive pressure is provided in the path 35a. . The inert gas discharge joint 33b communicates with a gas discharge path 35b, and a negative pressure regulator 36b for adjusting the inside of the manifold 31b to a desired negative pressure is provided in the path 35b.
[0047]
The positive pressure regulator 36a, the path 35a, the inert gas supply joint 33a, the inert gas discharge joint 33b, the path 35b, and the negative pressure regulator 36b flow into the pellicle space 100 and mix with a gas such as oxygen in the pellicle space 100. It can function as a gas control mechanism that controls the flow of the inert gas flowing out from the pellicle space 100.
[0048]
Next, a process of purging the pellicle space 100 with an inert gas will be described with reference to FIGS.
[0049]
First, the reticle 20 to which the pellicle 21 is attached is positioned and placed at a predetermined position on the reticle support base 29 by a reticle hand, a transport robot, or manually (not shown).
[0050]
The inert gas supply joint 33a and the inert gas discharge joint 33b are configured to press the inner sides of the O-rings 32a and 32b against the manifolds 31a and 31b attached to the pellicle frame pieces 30a and 30b of the porous material by the drive mechanism 34. Connected. The supply joint 33a and the discharge joint 33b are connected to an inert gas supply device and an inert gas suction device (not shown) via a supply path 35a and a discharge path 35b, respectively, and inert gas is supplied into the pellicle space 100. Simultaneously with the blowing, the gas in the pellicle space 100 is sucked and discharged to the outside of the airtight chamber 26.
[0051]
Since the blown inert gas passes through the pellicle frame piece 30a of the porous material, the flow rate from the pellicle frame piece 30a toward the opposite pellicle frame piece 30b is maintained with a very uniform flow rate per unit area. Flowing. The inert gas is discharged to the outside of the pellicle space 100 while maintaining homogeneity by the pellicle frame piece 30b made of a porous material for discharge. As a result, the mixture is efficiently mixed with oxygen, moisture and other impurities existing in the pellicle space without causing stagnation of the flow, and is discharged to the outside through the discharge manifold 31b provided on the porous pellicle frame piece 30b on the discharge side. The gas replacement is completed in a short time in the pellicle space.
[0052]
Since the porous material hardly allows gas to pass through if there is no pressure difference between the two sides of the porous material, even if the supply joint 33a and the discharge joint 33b are removed from the manifolds 31a and 31b after replacement with an inert gas, the reticle 20 with a pellicle remains. During a short period of time before being transferred to the stage, the pellicle space 100 exhibits the same behavior as the sealed space, and the concentration of the inert gas in the pellicle space 100 is maintained. In addition, since the porous material as the pellicle frame sides 30a and 30b also serves as a filter, the inflow of dust into the pellicle space 100 can be prevented. However, a filter for preventing particles or preventing chemical contamination may be separately provided in a path for supplying gas to the porous pellicle frame piece 30a.
[0053]
The inert gas supply joint 33a and the inert gas discharge joint 33b as shown in FIGS. 4 to 6 may be arranged in the reticle storage 18 (see FIG. 1). As a result, for the reticle that is carried from the outside into the exposure apparatus and is temporarily stored in the reticle storage 18 without being used for exposure, the inert gas purge in the pellicle space is not performed in the reticle load lock chamber 13. After the reticle is loaded into a predetermined slot in which the joint of the reticle storage 18 is disposed, it is possible to perform an inert gas purge in the pellicle space in the storage. As a result, it is possible to secure a sufficient purge time to reduce the inert gas concentration in the pellicle space to a low level in advance, and to further reduce or eliminate the inert gas purge time in the reticle load lock chamber 13. is there.
[0054]
Of course, the place where the purge mechanism including the inert gas supply joint and the inert gas discharge joint is arranged is not limited to the reticle stage, the reticle storage, and the reticle load lock chamber. It can be placed at various locations, such as in a reticle transport path within a sealed chamber. By placing the purge mechanism in the transport path, it is not necessary to transport the purge mechanism to the purge mechanism outside the transport path, so that it is possible to shorten the transport time of the entire exposure apparatus and improve productivity. There is an advantage that can be. In addition, the location of the purge mechanism is not limited to any one, and the purge mechanism is arranged at multiple locations to automatically select the inert gas purge at the optimal location according to the reticle usage plan. It is also possible to implement.
[0055]
[Second Embodiment]
7 and 8 are diagrams showing a schematic configuration of the purge mechanism (gas replacement device) according to the second embodiment of the present invention. Of these, FIG. 7 is a schematic sectional view of the purge mechanism as viewed from the side, and FIG. 8 is a view of FIG. 7 as viewed from below. This purge mechanism is a mechanism for purging the pellicle space with an inert gas, and can be applied to any exposure apparatus that uses a reticle with a pellicle, for example, a reticle storage (reticle stocker), a reticle inspection apparatus, a reticle. It can also be applied to a transport box or the like. That is, the present invention can be applied to various device manufacturing related apparatuses that use, handle, or inspect a reticle with a pellicle. Note that the same reference numerals are assigned to the same components as those in the first embodiment. Further, matters not particularly mentioned in this embodiment are the same as those in the first embodiment.
[0056]
In the first embodiment, the pellicle frame is partially (2 out of 4 sides) made of a porous material, and the space in the manifold connected to the pellicle frame is pressurized and depressurized to form the pellicle space. An inert gas is introduced to discharge the gas in the pellicle space. On the other hand, in this embodiment, the entire pellicle frame is made of a porous material, and the inert gas supply side (inflow side) is pressurized while the outflow side is not depressurized. That is, in this embodiment, the inert gas is supplied into the pellicle space through a very small part (inflow part) of the pellicle frame, and the inert gas is discharged from the pellicle space through the other most part (outflow part) of the pellicle frame. To do.
[0057]
Hereinafter, it will be described in more detail with reference to FIGS. In this embodiment, an inert gas supply joint 33a is connected via an O-ring 32a to a manifold 31a provided at a part (inflow part) of the pellicle frame 30 by a drive mechanism 34a. Then, after the inert gas supply joint 33a is connected, the pressurized inert gas is fed into the pellicle space 100 through the inert gas supply joint 33a. As shown in FIG. 8, the inert gas supply manifold 31 a is attached to a part of the pole (inflow part) of the pellicle frame 30. Therefore, when the inside of the manifold 31a is pressurized with an inert gas, only the part of the pellicle frame 30 functions as an inert gas inflow part 30e, and the other part of the pellicle frame serves as an inert gas outflow part. It functions as 30f.
[0058]
The inert gas that has passed through the inflow portion 30 e of the pellicle frame 30 flows radially toward the outflow portion 30 f of the pellicle frame 30. From the outflow part 30f, an inert gas flows out of the pellicle frame at a constant flow rate per area due to the nature of the porous material. The outflowing gas is discharged out of the hermetic chamber 26 through the inert gas discharge line 28 together with other gases in the hermetic chamber 26.
[0059]
Since the porous material has high piping resistance, it is necessary to give a certain pressure difference to both sides of the porous material in order to allow gas to permeate. However, in this embodiment, since the outside of the porous material 30f on the gas discharge side is atmospheric pressure, unless the pressure in the pellicle space 100 is made higher than the atmospheric pressure by the pressure difference or more, the porous material is gas. Does not penetrate. On the other hand, the pressure resistance performance of the pellicle film 21 is low. Therefore, in this embodiment, nitrogen is caused to flow into the pellicle space with a small pressure difference by increasing the area of the porous material constituting the outflow portion 30f.
[0060]
Compared with the first embodiment in which gas is forced to flow out of the pellicle space by applying a negative pressure to the outside of the pellicle space, this embodiment allows the gas to flow into the pellicle space and out of the pellicle space. The flow rate of inert gas that can be produced is small. Also, in this embodiment, unlike the first embodiment, an inflow portion 30e (corresponding to the pellicle frame piece 30a of the first embodiment) through which an inert gas flows into the pellicle frame enters the pellicle space. Since the distance to the outflow part 30f (corresponding to the pellicle frame piece 30b in the first embodiment) through which the gas flows out is not uniform in all parts, the gas replacement time is longer than that in the first embodiment. Tend to be. However, according to this embodiment, there is no manifold on the outflow side, and the pellicle frame itself can be made of a single material. Therefore, this embodiment is superior to the first embodiment in that the purge mechanism is simple because the outflow side gas discharge mechanism is unnecessary, and that the manufacturing cost of the purge mechanism can be reduced. ing. Further, this embodiment is superior to the first embodiment in that the reticle with a pellicle is simple and easy to manufacture, and that the manufacturing cost of the reticle with a pellicle can be reduced.
[0061]
The disadvantage in the above embodiment is caused by, for example, manufacturing the entire pellicle frame with a porous material and leaving the gas outflow side open to the atmosphere. Therefore, in this embodiment, similarly to the first embodiment, the gas outflow side may be set to a negative pressure to increase the gas inflow / outflow amount, or the upper and lower sides of the pellicle frame shown in FIG. The material may be sealed with a sealing material, and a gas outflow manifold 31b may be provided on the left side as in the first embodiment, and the gas may be discharged under a negative pressure therein.
[0062]
[Third Embodiment]
9 to 11 are diagrams showing a schematic configuration of a purge mechanism (gas replacement device) according to a third embodiment of the present invention. More specifically, FIG. 9 is a schematic view of the purge mechanism as viewed from the lateral direction, and FIG. 10 is a diagram showing a state in which an inert gas is caused to flow in the pellicle space by the purge mechanism shown in FIG. FIG. 11 is a view of FIG. 10 as viewed from below. Note that the same reference numerals are assigned to the same components as those in the first embodiment. Further, matters not particularly mentioned in this embodiment are the same as those in the first embodiment.
[0063]
This embodiment is characterized in that porous members 30a and 30b are provided outside the pellicle frame 22 having the air holes 24, and manifolds 31a and 31b are provided outside thereof. More specifically, in this embodiment, vent holes 24 are provided on two opposite sides of the pellicle frame 22 made of a non-porous material, and porous members 31a and 31b are provided on the outer sides of the two sides, respectively. Furthermore, manifolds 31a and 31b are provided outside the two porous members 31a and 31b, respectively.
[0064]
Hereinafter, a process of purging the pellicle space 100 with an inert gas will be described with reference to FIGS.
[0065]
First, the reticle 20 to which the pellicle 21 is attached is positioned and placed at a predetermined position on the reticle support base 29 by a reticle hand, a transport robot, or manually (not shown).
[0066]
The inert gas supply joint 33a and the inert gas discharge joint 33b are connected by the drive mechanism 34 with the O-rings 32a and 32b sandwiched between the manifolds 31a and 31b attached to the porous members 30a and 30b. The supply joint 33a and the discharge joint 33b are connected to an inert gas supply device and an inert gas suction device (not shown) via a supply path 35a and a discharge path 35b, respectively, and inert gas is supplied into the pellicle space 100. Simultaneously with the blowing, the gas in the pellicle space 100 is sucked and discharged to the outside of the airtight chamber 26.
[0067]
Since the porous member hardly allows gas to pass through if there is no pressure difference between the spaces on both sides of the porous member, even if the supply joint 33a and the discharge joint 33b are removed from the manifolds 31a and 31b after the replacement with the inert gas, the reticle 20 with a pellicle remains on the stage. During a short period of time before being transported to the pellicle, the pellicle space 100 behaves in the same manner as the sealed space, and the gas concentration in the pellicle space 100 is maintained. Moreover, since the porous members 30a and 30b also serve as a filter, the inflow of dust into the pellicle space 100 can be prevented. However, a filter for preventing particles or preventing chemical contamination may be separately provided in a path for supplying gas to the porous member 30a.
[0068]
According to this embodiment, since a reticle with a pellicle can be manufactured by, for example, attaching a porous member to the outside of a pellicle frame having four sides having vent holes, a porous material and a non-porous material can be used. Compared to the first embodiment in which a pellicle frame composed of four sides is combined, manufacturing of a reticle with a pellicle is easier. That is, according to this embodiment, the manufacturing process of the pellicle frame is simplified.
[0069]
[Fourth Embodiment]
Next, an example in which the purge mechanism according to the present invention is applied to a light source lens system of an exposure apparatus will be described as a fourth embodiment of the present invention. FIG. 12 is a view schematically showing a part (light source lens system) of the exposure apparatus according to the fourth embodiment of the present invention. Note that the same reference numerals are assigned to the same components as those in the first embodiment. Further, matters not particularly mentioned in this embodiment are the same as those in the first embodiment.
[0070]
The light source lens system includes optical elements such as a large number of lenses 37a to 37b and a mirror 38, and illuminates an illumination area on the reticle with laser light from the light source with uniform illuminance. These optical components are arranged inside the housing 39. The inside of the housing 39 is purged with an inert gas having a high concentration by an inert gas supply line 27 and an inert gas discharge line 28. However, when working with the housing 39 opened for maintenance or other reasons, the atmosphere flows into the housing 39, so that when the exposure apparatus is operated again, the interior of the housing 39 is replaced again from the atmosphere to an inert gas. There is a need to. However, when an optical component is arranged in the housing 39, for example, the space between the lenses 37a to 37c placed in the lens holding structure 40 is in a semi-sealed state. This is a place where gas does not flow easily and gas replacement is difficult.
[0071]
Therefore, in this embodiment, as in the first to third embodiments, a purge mechanism that supplies an inert gas to the replacement space through the porous material is incorporated in the lens holding structure 40.
[0072]
Specifically, in this embodiment, as shown in FIG. 12, a porous material 30a for supplying an inert gas is provided on the wall (for example, inside the wall) of the lens holding structure 40 to hold the lens. A part of the structure 40 is processed into a manifold shape, and a pressurized gas is sent through the inert gas supply path 35a, and the inert gas is supplied to the inter-lens space through the porous material 30a. Since the inert gas blown into the inter-lens space passes through the porous material 30a, it flows toward the opposite surface (left side in the figure) with high uniformity in the surface direction of the porous material 30a. Then, the gas in the inter-lens space is discharged out of the lens holding structure 40 through the discharge hole 41 provided in the facing surface. As a result, oxygen, moisture, and other impurities existing in the inter-lens space can be efficiently mixed with the inert gas without causing stagnation, and these can be discharged to the outside through the discharge port 41. This completes the gas replacement in the inter-lens space.
[0073]
Therefore, when the inert gas concentration in the replacement space (inter-lens space) has decreased due to maintenance or the like, it is possible to shorten the waiting time of the exposure apparatus until the inert gas concentration increases. In this example, the light source lens system has been described. However, the method of supplying the inert gas using the porous material is not limited to the light source lens system, but in any optical components such as a projection lens system and a measurement lens system and other mechanisms. It can be applied to purging non-replacement space.
[0074]
[Device manufacturing method]
Next, a semiconductor device manufacturing process using the above exposure apparatus will be described. FIG. 13 is a diagram showing a flow of an entire manufacturing process of a semiconductor device. In step 1 (circuit design), the semiconductor device circuit is designed. In step 2 (mask production), a mask is produced based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the mask and wafer. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these processes, the semiconductor device is completed and shipped (step 7).
[0075]
FIG. 14 shows a detailed flow of the wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern is transferred onto the wafer by the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.
[0076]
As described above, according to a preferred embodiment of the present invention, in a projection exposure apparatus using ultraviolet light such as a fluorine excimer laser as a light source, the inert gas purge in the pellicle space of the reticle with the pellicle carried into the apparatus Can be efficiently performed in a short time.
[0077]
In addition, even when the inert gas purge space is broken by maintenance or adjustment, it is possible to return to the required purge level in a short time, thereby reducing the waiting time of the apparatus.
[0078]
Thus, highly accurate and stable exposure amount control can be performed without impairing the productivity of the exposure apparatus, and a fine circuit pattern can be efficiently and stably projected onto the substrate.
[0079]
【The invention's effect】
  According to the present invention, for example,Surrounded by reticle, pellicle and pellicle frameReduce the non-uniformity and stagnation of the inert gas flow in the space,Replace the gas in the space with an inert gasTime can be shortened.
[Brief description of the drawings]
FIG. 1 is a view showing the schematic arrangement of an exposure apparatus according to a preferred embodiment of the present invention.
FIG. 2 is a schematic diagram showing the structure of a reticle with a pellicle.
3 is a schematic diagram showing an example of a reticle transport path in the exposure apparatus shown in FIG. 1. FIG.
FIG. 4 is a diagram showing a schematic configuration of a purge mechanism (gas replacement device) according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a schematic configuration of a purge mechanism (gas replacement device) according to the first embodiment of the present invention.
FIG. 6 is a diagram showing a schematic configuration of a purge mechanism (gas replacement device) according to the first embodiment of the present invention.
FIG. 7 is a diagram showing a schematic configuration of a purge mechanism (gas replacement device) according to a second embodiment of the present invention.
FIG. 8 is a diagram showing a schematic configuration of a purge mechanism (gas replacement device) according to a second embodiment of the present invention.
FIG. 9 is a diagram showing a schematic configuration (gas replacement device) of a purge mechanism according to a third embodiment of the present invention.
FIG. 10 is a diagram showing a schematic configuration (gas replacement device) of a purge mechanism according to a third embodiment of the present invention.
FIG. 11 is a diagram showing a schematic configuration (gas replacement device) of a purge mechanism according to a third embodiment of the present invention.
FIG. 12 is a drawing schematically showing a part (light source lens system) of an exposure apparatus according to a fourth embodiment of the present invention.
FIG. 13 is a diagram showing a flow of an entire manufacturing process of a semiconductor device.
FIG. 14 is a diagram showing a detailed flow of a wafer process.
[Explanation of symbols]
1: reticle stage, 2: lens barrel, 3: wafer stage, 4: illumination optical system, 5: routing optical system, 6: F₂Laser, 7: Masking blade, 8, 9: Housing, 10, 11, 12: Air conditioner, 13: Reticle load lock, 14: Wafer load lock, 15: Reticle hand, 16: Wafer hand, 17: Reticle alignment mark , 18: reticle storage, 19: pre-alignment unit, 20: reticle, 21: pellicle, 22: pellicle frame, 23: pellicle membrane, 24: vent hole, 25: foreign substance inspection device, 26: airtight chamber or load lock chamber 27: inert gas supply line, 28: inert gas discharge line, 29: reticle support, 30: pellicle frame, 30a: porous material pellicle frame (gas supply side), 30b: porous material pellicle frame (gas Discharge side), 30c, 30d: non-porous pellicle frame, 30e: inflow portion, 30f: outflow portion, 31a: gas supply side manifold 31b: gas discharge manifold, 32: O-ring, 33a: inert gas supply joint, 33b: inert gas discharge joint, 34: drive mechanism, 35a: inert gas supply path, 35b: inert gas discharge port , 36a: positive pressure regulator, 36b: negative pressure regulator, 37a to 37c: light source lens system constituting lens, 38: light source lens system mirror, 39: light source lens system gas sealed casing, 40: light source lens system holding structure, 41 Inert gas outlet, 100: pellicle space

Claims (8)

A reticle with a pellicle, comprising a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle,
  The pellicle frame includes first and second pellicle frame pieces facing each other,
  The first and second pellicle frame pieces are each made of a porous material,
  The reticle with pellicle has a first manifold that is disposed outside the first pellicle frame piece, has a first opening, and has an inner width equal to the inner width of the pellicle frame, By supplying an inert gas through the first opening, the space surrounded by the first pellicle frame piece and the first manifold is maintained at a positive pressure.
A reticle with a pellicle characterized by this. A second manifold disposed outside the second pellicle frame piece, having a second opening, and having an inner width equal to the inner width of the pellicle frame; The space surrounded by the second pellicle frame piece and the second manifold is maintained at a negative pressure by discharging gas through
The reticle with a pellicle according to claim 1. Device manufacturing related equipment,
  A support means for supporting a reticle with a pellicle, including a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle;
  Supply means for supplying an inert gas into a space surrounded by the reticle, the pellicle and the pellicle frame of the reticle with the pellicle supported by the support means;
Have
  The pellicle frame includes first and second pellicle frame pieces facing each other,
  The first and second pellicle frame pieces are each made of a porous material,
  The reticle with the pellicle has a first manifold that is disposed outside the first pellicle frame piece, has a first opening, and has an inner width equal to the inner width of the pellicle frame, By supplying an inert gas through the first opening, a space surrounded by the first pellicle frame piece and the first manifold is maintained at a positive pressure.
  The supply means includes
  An inert gas is supplied into the space surrounded by the reticle, the pellicle, and the pellicle frame through the first opening.
Device manufacturing related apparatus characterized by the above. A discharge means for discharging gas from the space surrounded by the reticle, the pellicle and the pellicle frame;
  The reticle with a pellicle has a second manifold that is arranged outside the second pellicle frame piece, has a second opening, and has an inner width equal to the inner width of the pellicle frame, By exhausting gas through the second opening, the space surrounded by the second pellicle frame piece and the second manifold is maintained at a negative pressure,
  The discharge means discharges gas from the space surrounded by the reticle, the pellicle, and the pellicle frame through the second opening.
The device manufacturing related apparatus according to claim 3. 5. The storage device according to claim 3, wherein the storage device stores a reticle with a pellicle, an inspection device that inspects a reticle with a pellicle, and a transport box for transporting a reticle with a pellicle. Device manufacturing related equipment. An exposure apparatus that exposes a substrate through a reticle with a pellicle,
  A support means for supporting a reticle with a pellicle, including a reticle, a pellicle, and a pellicle frame disposed on the reticle and supporting the pellicle;
  Supply means for supplying an inert gas into a space surrounded by the reticle, the pellicle and the pellicle frame of the reticle with the pellicle supported by the support means;
Have
  The pellicle frame includes first and second pellicle frame pieces facing each other,
  The first and second pellicle frame pieces are each made of a porous material,
  The reticle with the pellicle has a first manifold that is disposed outside the first pellicle frame piece, has a first opening, and has an inner width equal to the inner width of the pellicle frame, By supplying an inert gas through the first opening, a space surrounded by the first pellicle frame piece and the first manifold is maintained at a positive pressure.
  The supply means includes
  An inert gas is supplied into the space surrounded by the reticle, the pellicle, and the pellicle frame through the first opening.
An exposure apparatus characterized by that. A discharge means for discharging gas from the space surrounded by the reticle, the pellicle and the pellicle frame;
  The reticle with a pellicle has a second manifold that is arranged outside the second pellicle frame piece, has a second opening, and has an inner width equal to the inner width of the pellicle frame, By exhausting gas through the second opening, the space surrounded by the second pellicle frame piece and the second manifold is maintained at a negative pressure,
  The discharge means discharges gas from the space surrounded by the reticle, the pellicle, and the pellicle frame through the second opening.
The exposure apparatus according to claim 6. Using the exposure apparatus according to claim 6 or 7 to expose a substrate through a reticle with a pellicle;
  Developing the exposed substrate; and
A device manufacturing method comprising:

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