JP2006060037A - Exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus wherein the purging time of a pellicle space of the space surrounded by a reticle carried in the exposure apparatus and a pellicle can be so shortened as to be able to shorten the carrying-in time of the reticle and as to improve the productivity of semiconductor devices. <P>SOLUTION: Feeding and exhausting nozzles 33, 34 for feeding and exhausting respectively an inert gas are so provided approximately or adhesively to one or more feeding ports a and to one or more exhausting ports b which are provided respectively in a pellicle frame 25 as to purge a pellicle space 20 via these feeding and exhausting ports, and as to apply a pressure nearly equal to the pressure of the pellicle space from the outside of a pellicle film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus that transfers an original pattern such as a mask or a reticle onto a photosensitive substrate such as a semiconductor wafer, and more particularly to an exposure apparatus that uses an original having a dust-proof pellicle.

  Conventionally, in the manufacturing process of semiconductor elements such as LSI or VLSI formed from ultrafine patterns, a circuit pattern drawn on an original plate such as a mask or reticle is reduced and projected onto a substrate such as a wafer coated with a photosensitive agent. A reduction type projection exposure apparatus for printing and forming is used. As the mounting density of semiconductor elements has increased, further miniaturization of patterns has been required, and at the same time as the development of resist processes, the miniaturization of exposure apparatuses has been addressed.

  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.

With respect to the exposure wavelength, a KrF excimer laser having an oscillation wavelength near 248 [nm] from an i line of 365 [nm] and an ArF excimer laser having an oscillation wavelength near 193 [nm] have recently been developed. Further, a fluorine (F ₂ ) excimer laser having an oscillation wavelength near 157 [nm] has been developed.

It is known that a deep ultraviolet ray, particularly a fluorine (F ₂ ) excimer laser having an oscillation wavelength near 157 [nm], has a plurality of oxygen (O ₂ ) absorption bands in the vicinity of the emission wavelength. Since the fluorine excimer laser has a short wavelength of 157 [nm], its application to an exposure apparatus is in progress, but the wavelength of 157 [nm] is generally in a wavelength region called vacuum ultraviolet. However, when light in this wavelength region is applied to an exposure apparatus, light absorption by oxygen is large, so that the atmosphere hardly transmits light and it is necessary to create an environment in which the oxygen concentration is sufficiently reduced.

According to Non-Patent Document 1 (“Photochemistry of Small Molecules” (Hideo Okabe, A Wiley-Interscience Publication, 1978, p. 178), the absorption coefficient of oxygen for light with a wavelength of 157 [nm] is about 190 [atm ^{− 1} cm ⁻¹ ], which means that when light having a wavelength of 157 [nm] passes through a gas having an oxygen concentration of 1 [%] at 1 atm, the transmittance per 1 [cm] is given by the following formula. It shows that there is only a required value of 0.150.
T = exp (−190 × 1 [cm] × 0.01 [atm]) = 0.150

Moreover, ozone absorbs the above-mentioned light to generate ozone (O ₃ ). This ozone further increases the light absorption and significantly reduces the transmittance, and various products resulting from ozone. Adheres to the surface of the optical element, reducing the efficiency of the optical system. In addition, the above-described light greatly absorbs not only oxygen but also moisture, so that the transmittance is significantly reduced.

Therefore, in the light path of the exposure light of the projection exposure apparatus that uses far ultraviolet rays, in particular, fluorine (F ₂ ) excimer laser light having a wavelength in the vicinity of 157 [nm], the transmittance of the exposure light and the uniformity of the transmittance are improved. In order to ensure this, a method has been adopted in which the oxygen concentration and water concentration present in the optical path are kept at a low level of several ppm order or less by means of purging with an inert gas such as nitrogen or helium.

In the case of the above-described conventional purge means, the illumination optical system and the projection optical system can be a sealed container, so that the internal purge can be performed relatively easily. In particular, the method of purging in the optical path near the reticle or wafer is the reticle. This is a problem because the wafer is a movable body of the exposure apparatus, and in the more recent mainstream step-and-scan type projection exposure apparatus, both the reticle and the wafer are scanned during exposure, and so on. It becomes a problem. Therefore, the entire reticle stage and wafer stage are enclosed by a casing, purged with an inert gas such as N _2, and a load lock mechanism is provided at the portion connecting the inside and outside of the exposure apparatus, so that the reticle and When loading a wafer, the load lock mechanism once shuts off the outside air, purges impurities in the load lock mechanism with an inert gas, and then loads the wafer into the exposure apparatus.

For example, FIG. 10 is a schematic cross-sectional view showing an example of a semiconductor exposure apparatus using a fluorine (F ₂ ) excimer laser as a light source and having a load lock mechanism. In FIG. 10, 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 onto a wafer, and 3 is mounted on a wafer in X, Y, Z, θ and tilt directions. A wafer stage to be driven, 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 fluorine (F ₂ ) as a light source. An excimer laser unit, 7 is a masking blade for shielding exposure light so that only the pattern area on the reticle is illuminated, 8 and 9 are cases for covering the exposure optical axes around the reticle stage 1 and the wafer stage 3, respectively, and 10 is a projection. He air conditioner to adjust the inside of the optical system 2 and the illumination optical system 4 to a predetermined He atmosphere, 11 and 12 inside the respective housing 8 and 9 given N ₂ Kiri N ₂ air conditioner for adjusting the air, 13 and 14 reticle load lock and wafer loadlock use when carried in each case 8 and 9 the reticle and the wafer, 15 and 16 each for carrying a reticle and wafer The reticle hand and the wafer hand, 17 is a reticle alignment mark used for reticle position adjustment, 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. If necessary, the entire apparatus is housed in an environmental chamber (not shown), and air controlled to a predetermined temperature is circulated in the environmental chamber to keep the temperature in the chamber constant.

  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 pattern surface of the reticle, thereby suppressing the frequency of occurrence of defects due to foreign matter transfer onto the wafer. Although it is impossible to prevent foreign matter from adhering to the surface of the pellicle and the blank surface of the reticle (opposite surface of the pattern surface), these surfaces are separated from the pattern surface by several millimeters, so they do not form an image on the wafer. Since the illuminance becomes uneven, the allowable size of the foreign matter becomes very large, and the occurrence frequency of defects is suppressed. In general, a reticle and a pellicle are bonded together in a clean environment by a pellicle bonding apparatus, and foreign substances are prevented from adhering to a pattern surface in the path to the exposure apparatus and the exposure apparatus thereafter. In addition, as the kind of pellicle film, for example, a so-called soft pellicle, which is a thin film having a thickness of about 1 to 2 μm mainly composed of nitrocellulose or the like, and a thickness of 100 made of fluorine-doped quartz or the like, for example. There is what is called a so-called hard pellicle, which is a glass material of about ˜800 μm.

  FIG. 11 is a schematic diagram showing the structure of this pellicle. The pellicle 24 is attached to the pattern surface side of the reticle 23 using an adhesive or the like. The pellicle 24 includes a pellicle frame 25 having a size that surrounds the reticle pattern, and a pellicle film 26 that transmits exposure light attached to one end face thereof. If the pellicle space, which is the space surrounded by the pellicle 24 and the reticle 23, is completely sealed, there is a problem that the pellicle swells or deforms due to an atmospheric pressure difference or an oxygen concentration difference inside and outside the pellicle space. Is provided with a vent hole 27 so that gas can flow inside and outside the pellicle space. In addition, 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 27.

  FIG. 12 is a schematic diagram showing an example of the transport path of the reticle 23 in the exposure apparatus shown in FIG. In FIG. 12, reference numeral 90 denotes a foreign matter inspection apparatus that measures the size and number of foreign matters such as dust adhering to the surface of the reticle 23 and the surface of the pellicle 24. A reticle 23 with a pellicle 24 is carried into a reticle load lock 13 serving as an entrance of an exposure apparatus, either manually or by a transport device (not shown). Next, the interior of the reticle load lock chamber 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 apparatus 90. 23 is conveyed.

  At this time, if a pellicle is affixed to the reticle, the exposure light is absorbed at the time of exposure unless oxygen and moisture are sufficiently removed in the pellicle space. However, since the pellicle space has a structure that allows the outside air to flow only through the relatively small vent 27 (FIG. 11), the load lock chamber has a predetermined inertness in order to complete the replacement in the pellicle space. After reaching the gas concentration, a longer time is required and the productivity is greatly deteriorated.

  In order to solve this problem, for example, an invention described in Patent Document 1 (Japanese Patent Laid-Open No. 2001-230202) has been proposed. In the proposed fourth embodiment, vent holes are provided on two sides of the pellicle frame, and each of the vent holes is provided with an opening / closing lid that is energized by a spring from the inside of the pellicle frame to close the vent hole. Insert the leading edge of the air supply and exhaust pipes into the vent and push the open / close lid to the inside of the pellicle space. Insert the leading edge of the air supply and exhaust pipes into the pellicle space and supply inert gas from there. Thus, the purge in the pellicle space is efficiently performed and the replacement can be completed in a short time.

  However, in this proposal, since the leading end portions of the air supply pipe and the exhaust pipe are pressed against the open / close lid inside the pellicle space, that is, contacted and slid, foreign matter is generated in the pellicle space and the supplied inert gas is supplied. There is a problem that foreign matters are caused to flow and adhere to the pellicle pattern surface due to the flow of gas. In addition, when the leading end of the air supply pipe and exhaust pipe is inserted into the vent and the open / close lid is opened and when the lid is pulled out and closed, the outside of the pellicle space communicates with the inside, so that foreign matter enters the inside from the outside. May adhere to the pellicle pattern.

  On the other hand, Japanese Patent Application Laid-Open No. 2002-158153 proposes a method for efficiently purging the pellicle space while solving these problems. This is because a plurality of vent holes are provided on each of the two sides of the pellicle frame, and the movable supply nozzle and the discharge nozzle provided in the load lock chamber are brought into contact with each other so as to surround the vent hole on the side surface of the pellicle frame. An inert gas is supplied to and discharged. According to this proposal, since a dust removal filter can be attached to the vent hole, even if foreign matter is generated when the nozzle contacts the pellicle frame, it is removed by the dust removal filter. Does not occur.

  By the way, in the proposal by the above-mentioned patent document 1 and patent document 2, since the method of supplying and discharging the inert gas directly in the pellicle space is taken, the deformation and breakage of the pellicle due to the pressure fluctuation in the pellicle space are prevented. That is an important issue. For this reason, both proposals are equipped with a displacement measuring device that measures the displacement of the pellicle surface, and controls the amount of inert gas supplied or discharged so that the deformation of the pellicle is within a predetermined range based on the amount of displacement. is doing. That is, the pressure in the pellicle space is controlled to be substantially equal to the outer pressure. In order to efficiently purge the pellicle space in this state, it is disclosed in Patent Document 2 that the positive pressure on the supply side and the negative pressure on the exhaust side are distributed around the pressure outside the pellicle space. Has been. It can easily be seen that maximizing the difference between the supply side pressure and the exhaust side pressure maximizes the purge efficiency and shortens the purge time. Regarding the pressure outside the pellicle space, it is disclosed in Patent Document 1 that the pressure is from 0.1 Pa to slightly higher than atmospheric pressure, and in Patent Document 2, there is no detailed description. Is considered to be almost atmospheric pressure. If the pressure outside the pellicle space is approximately 1 atm, the negative pressure on the exhaust side is limited to 0.5 to 0 atm, so the positive pressure on the supply side is 1.5 to 2 atm. Barometric pressure becomes the limit. That is, when the pressure outside the pellicle space is approximately 1 atm, the pressure difference between the supply side pressure and the exhaust side pressure and the pellicle space is 0.5 to 1 atm in order to prevent deformation and breakage of the pellicle. Since it is the limit, the flow resistance of the dust removal filter may be large, and there is a problem that the flow rate of the inert gas cannot be increased so much and the replacement time is long.

  On the other hand, the invention described in Patent Document 3 (Japanese Patent Laid-Open No. 2001-267200) has been proposed in order to solve this problem. This is because a plurality of vent holes are provided on each of the two sides of the pellicle frame, and the pellicle frame is driven by the pellicle frame abutting portion having the same shape as the pellicle frame which is the end surface of the third chamber provided in the load lock chamber. When contacted, the vent on one side communicates with the first chamber, the vent on the other side communicates with the second chamber, the pellicle surface faces the third chamber, and the reticle enters the fourth chamber. It comes to face. Further, the third chamber is provided with a displacement measuring device for measuring the displacement near the center of the pellicle surface. In this state, the first chamber is pressurized with an inert gas and the second chamber is depressurized, so that the inert gas is forced to flow in and out through the vent hole in the pellicle space, while the pellicle surface is The pressure in the third chamber is controlled so that the displacement of the pellicle surface does not change so as not to bend and break due to an increase in the internal pressure of the space.

However, in this proposal, the first chamber and the second chamber are separated without directly communicating with each other, and the inert gas passes through the vent hole with a filter from the first chamber to the pellicle space and from the pellicle space to the second chamber. It is assumed that it flows. That is, if there is a gap between the partition wall partitioning the first chamber and the second chamber and the side surface of the pellicle frame, the first chamber and the second chamber communicate with each other, and the inflow of inert gas into the pellicle space Remarkably lowered, it becomes difficult to efficiently purge the target pellicle space. Therefore, it is very important how to eliminate the gap between the partition wall partitioning the first chamber and the second chamber and the side surface of the pellicle frame, but this proposal does not disclose that point. Actually, since the outer tolerance of the current pellicle frame is about ± 0.5 mm, it is not allowed to leave the gap as it is. Therefore, for example, it is conceivable to absorb the gap with an elastic body such as rubber, but there is a problem that large foreign matter is generated and adheres to the pellicle surface or the like by contact and sliding. Although it is conceivable to close the gap with a movable body, there is a problem that the mechanism becomes complicated, the driving time increases, and the productivity is deteriorated. In addition, it is conceivable to tighten the outer tolerance of the pellicle frame to eliminate almost all the gaps, but there is a problem that the cost of the pellicle rises and a complicated mechanism is required because it is set by fitting. . Thus, in this proposal, since it is necessary to divide and seal the first chamber, the second chamber, and the third chamber using a three-dimensional pellicle frame, these problems occur.
“Photochemistry of Small Molecules” (Hideo Okabe, A Wiley-Interscience Publication, 1978, p. 178) JP 2001-230202 A JP 2002-158153 A JP 2001-267200 A

  The present invention has been made in view of the above-described problems. In an exposure apparatus that transfers a pattern of an original having a pellicle to a photosensitive substrate, the transmittance of exposure light in a gap between the original and the pellicle film in the exposure apparatus. It is another object of the present invention to provide an exposure apparatus that can ensure uniformity of transmittance and perform high-precision printing.

In order to solve the above problems, the exposure apparatus of the present invention comprises:
An exposure apparatus for transferring a pattern of an original plate having a pellicle comprising a pellicle film and a pellicle frame having one or more supply ports and one or more discharge ports to a photosensitive substrate,
A supply nozzle for supplying an inert gas opposite to the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging gas opposite to the discharge port;
A nozzle proximity mechanism for bringing the discharge nozzle close to or close to the discharge port;
Surrounding means for enclosing at least the outside of the pellicle film of the original plate;
Means for supplying an inert gas into the surrounding means;
Means for discharging gas from within the surrounding means;
Controlling at least one of the pressure of the inert gas supplied to the supply nozzle and the pressure of the gas discharged from the discharge nozzle, and the pressure of the inert gas supplied into the surrounding means and the pressure of the gas discharged from the surrounding means Pressure control means to
It is characterized by having.

  Here, the surrounding means is, for example, a load lock chamber having one or more doors and a pellicle pressurizing chamber that forms a sealed space outside the pellicle membrane. The pressure control means preferably controls the gas pressures so that the pressure difference between the inside and the outside of the pellicle membrane is the same or substantially the same. The gas pressure control includes means for detecting the pressure outside the pellicle film and the pressure or pressure difference in the supply nozzle and the discharge nozzle, and the pressure outside the pellicle film, the supply nozzle and the discharge nozzle Although the absolute value of the pressure difference with each of them may be controlled to be the same or substantially the same, the deformation of the pellicle film is detected and each gas pressure is controlled so that the deformation is minimized. You may do it.

  The total flow resistance of the supply port of the pellicle frame and the total flow resistance of the supply port of the surrounding means are the same or substantially the same, and the total flow resistance of the discharge port of the pellicle frame and the discharge of the surrounding means It is preferable that the total amount of the outlet channel resistance is the same or substantially the same. In this case, the supply port of the pellicle frame and the supply port of the surrounding means are connected to a common supply path, and the discharge port of the pellicle frame and the discharge port of the surrounding means are connected to a common discharge path. There is an advantage that a pressure sensor and a deformation sensor are not required, and only one gas supply system and exhaust system are required. A better result can be expected when the volume of the pellicle pressurizing chamber and the volume of the space surrounded by the pellicle frame, the pellicle film and the original plate are the same or substantially the same.

  According to the present invention, the purge time of the space surrounded by the reticle and the pellicle when loading the reticle having the pellicle can be greatly shortened, the reticle loading time is shortened, the productivity is improved, and the reticle and the pellicle are surrounded. Therefore, it is possible to ensure the transmittance of the exposure light and the uniformity of the transmittance in the open space, and to perform highly accurate printing.

An exposure apparatus according to a preferred first embodiment of the present invention includes:
In an exposure apparatus that uses ultraviolet light as exposure light and irradiates a photosensitive substrate with a pattern of an original through a projection optical system,
The original plate is provided with a pellicle composed of a pellicle film and a pellicle frame,
The pellicle frame has one or more supply ports and one or more discharge ports,
The exposure apparatus is provided with a load lock chamber having one or more doors,
The load lock chamber includes a means for supplying an inert gas and a means for discharging the gas.
Inside the load lock chamber,
A supply nozzle for supplying an inert gas facing the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging the gas opposite to the discharge port;
A nozzle proximity mechanism for bringing the discharge nozzle close to or close to the discharge port;
Means for detecting a pressure difference between the supply nozzle and the load lock chamber;
Means for detecting the pressure difference in the discharge nozzle and the load lock chamber,
The exposure apparatus includes
Control means for controlling the pressure of the inert gas supplied to the load lock chamber or the pressure of the discharged gas;
Control means for controlling the pressure of the inert gas supplied to the supply nozzle and the pressure of the gas discharged from the discharge nozzle is provided.

An exposure apparatus according to a preferred second embodiment of the present invention includes:
In an exposure apparatus that uses ultraviolet light as exposure light and irradiates a photosensitive substrate with a pattern of an original through a projection optical system,
The original plate is provided with a pellicle composed of a pellicle film and a pellicle frame,
The pellicle frame has one or more supply ports and one or more discharge ports,
The exposure apparatus is provided with a load lock chamber having one or more doors,
The load lock chamber includes a means for supplying an inert gas and a means for discharging the gas.
Inside the load lock chamber,
A supply nozzle for supplying an inert gas facing the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging the gas opposite to the discharge port;
A nozzle proximity mechanism for bringing the discharge nozzle close to or close to the discharge port;
Means for detecting a pressure difference between the supply nozzle and the load lock chamber;
Means for detecting a pressure difference between the discharge nozzle and the load lock chamber;
Means for detecting the amount of displacement of the pellicle membrane;
The exposure apparatus includes
Control means for controlling the pressure of the inert gas supplied to the load lock chamber or the pressure of the discharged gas;
Control means for controlling the pressure of the inert gas supplied to the supply nozzle or the pressure of the gas discharged from the discharge nozzle is provided.

An exposure apparatus according to a preferred third embodiment of the present invention includes:
In an exposure apparatus that uses ultraviolet light as exposure light and irradiates a photosensitive substrate with a pattern of an original through a projection optical system,
The original plate is provided with a pellicle composed of a pellicle film and a pellicle frame,
The pellicle frame has one or more supply ports and one or more discharge ports,
The exposure apparatus includes
Providing a pellicle pressurizing chamber in close contact with the pellicle frame;
The pellicle pressurizing chamber has means for supplying an inert gas and means for discharging the gas;
Means for detecting the amount of displacement of the pellicle film,
The exposure apparatus includes
A supply nozzle for supplying an inert gas facing the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging the gas opposite to the discharge port;
A nozzle proximity mechanism for bringing the discharge nozzle close to or close to the discharge port;
Means for detecting a pressure difference between the supply nozzle and the pellicle pressurizing chamber;
A means for detecting a pressure difference in the discharge nozzle and the pellicle pressurizing chamber;
Control means for controlling the pressure of the inert gas supplied to the pellicle pressurizing chamber or the pressure of the discharged gas;
Control means for controlling the pressure of the inert gas supplied to the supply nozzle or the pressure of the gas discharged from the discharge nozzle is provided.

An exposure apparatus according to a preferred fourth embodiment of the present invention includes:
In an exposure apparatus that uses ultraviolet light as exposure light and irradiates a photosensitive substrate with a pattern of an original through a projection optical system,
The original plate is provided with a pellicle composed of a pellicle film and a pellicle frame,
The pellicle frame has one or more supply ports and one or more discharge ports,
The exposure apparatus includes
Providing a pellicle pressurizing chamber in close contact with the pellicle frame;
In the pellicle pressurizing chamber,
With one or more supply ports and one or more discharge ports,
The total amount of channel resistance of the supply port of the pellicle frame and the total amount of channel resistance of the supply port of the pellicle pressurizing chamber are substantially the same,
The total amount of channel resistance at the outlet of the pellicle frame and the total amount of channel resistance at the outlet of the pellicle pressurizing chamber are substantially the same,
A supply nozzle for supplying an inert gas close to or in close proximity to the supply port of the pellicle pressurizing chamber;
A discharge nozzle for discharging an inert gas close to or in close proximity to the discharge port of the pellicle pressurizing chamber;
The exposure apparatus includes
A supply nozzle for supplying an inert gas facing the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging the gas opposite to the discharge port;
A nozzle proximity mechanism is provided for bringing the discharge nozzle close to or close to the discharge port;
Control means for controlling the pressure of the inert gas supplied to the supply nozzle or the pressure of the gas discharged from the discharge nozzle is provided.

According to the above-described embodiment, when ultraviolet light is used as the exposure light, the space surrounded by the reticle and pellicle when the reticle is carried in the exposure apparatus using ultraviolet light, particularly fluorine (F ₂ ) excimer laser light. The purge time can be greatly shortened, the reticle loading time is shortened, the productivity is improved, the exposure light transmittance and the uniformity of the transmittance in the space surrounded by the reticle and pellicle can be ensured, and high-precision printing is achieved. It can be carried out.

Embodiments of the present invention will be described below with reference to the drawings.
[First embodiment]
1 and 2 are diagrams showing a first embodiment of the present invention. FIG. 1 is a plan view showing a purge mechanism for purging the pellicle space with an inert gas, and shows the load lock chamber 13 in FIG. FIG. 2 is a cross-sectional view taken along AA in FIG. An external door 28 is provided on the outside air side of the load lock chamber 13, and an internal door 29 is provided on the reticle purge chamber 21 (housing 8 in FIG. 10) side. When the reticle 23 is carried in, the inner door 29 is closed, the outer door 28 is opened, and the reticle is placed on the four support tables 30 provided in the load lock chamber 13 by the reticle conveying means (not shown). After positioning 23 and retracting the reticle conveying means, the external door 28 is closed. FIG. 2 shows this state. It is also possible to separately provide a positioning mechanism for positioning the reticle 23 on the support base more precisely, thereby making it possible to more precisely align the nozzle and the pellicle frame, which will be described later, and to leak inert gas. Can be minimized. Further, the support base 30 may be provided with a suction groove as necessary so that the reticle can be fixed by vacuum suction after positioning of the reticle is completed.

  A pellicle 24 is affixed to the reticle 23 in advance before being carried into the exposure apparatus. The pellicle 24 includes a pellicle frame 25 and a pellicle film 26. The pellicle film 26 is a so-called soft pellicle or hard pellicle. The pellicle frame 25 is provided with a plurality of supply ports a and a plurality of discharge ports b for supplying and discharging an inert gas. Dust filters 31 and 32 are provided outside all the supply ports a and the discharge ports b. Is provided. In addition, the total amount of the channel resistance at all the supply ports a and the total amount of the channel resistance at all the discharge ports b including the channel resistances of the dust removal filters 31 and 32 are substantially the same.

  A supply nozzle 33 and a supply nozzle proximity mechanism 34 are arranged at a fixed interval from the supply port a, and a discharge nozzle 35 and a discharge nozzle proximity mechanism 36 are arranged at a fixed interval from the discharge port b. The supply nozzle proximity mechanism 34 and the discharge nozzle proximity mechanism 36 have a guide and a drive unit that are movable in at least one direction. As shown in FIG. 3, the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are the end surfaces of the pellicle frame. Close and close to align at a predetermined position.

  An inert gas supply device 40 is connected to the supply nozzle 33 via a supply path 39, and a pressure adjusting device 41 and a valve 42 for adjusting the supply pressure of the inert gas are provided in the supply path 39. Controlled by the control unit 53. The pressure sensor 47 is connected to the pressure propagation paths 48 and 49 so as to detect the pressure in the supply nozzle 37 and the pressure in the load lock chamber 13 or the pressure difference between them, and the supply is based on the pressure in the load lock chamber. The relative pressure value in the nozzle 37 is sent to the control unit 53. Further, an inert gas suction device 44 is connected to the discharge nozzle 35 via a discharge path 43, and a pressure adjusting device 45 and a valve 46 for adjusting the discharge pressure of the inert gas are provided in the middle of the discharge path 43. Provided and controlled by the control unit 53. The pressure sensor 50 is connected to the pressure propagation paths 51 and 52 so as to detect both pressures in the discharge nozzle 35 and the load lock chamber 13 or a pressure difference therebetween, and the pressure in the load lock chamber is used as a reference. The relative pressure value in the discharge nozzle 38 is sent to the control unit 53.

  As shown in FIG. 3, after the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are brought into close contact with the end surface of the pellicle frame of the loaded reticle 23, the control unit 53 opens the valves 42 and 46, and further the pressure adjusting device 41, The relative pressure value in the supply nozzle 37 is gradually increased while controlling the absolute value of the relative pressure value with respect to the load lock chamber 13 in the supply nozzle 37 and the discharge nozzle 38 to be within an allowable value. The relative pressure value in the discharge nozzle 38 is gradually lowered. At this time, the total amount of flow path resistance at the supply port a and the discharge port b is almost the same, that is, the pressure loss at the supply port a and the supply port b is almost the same. 37 and the pressure in the discharge nozzle 38 are approximately intermediate values, and are controlled so as to substantially match the pressure in the load lock chamber 13. Accordingly, there is almost no pressure difference between the pellicle space 20 and the load lock chamber 13, and the pellicle space 26 is hardly deformed and the inert gas is forcibly supplied to the pellicle space 20. Since it is forcibly discharged after being mixed with the air in 20, the concentration of the exposure light absorbing material such as oxygen and moisture gradually decreases. Note that the control unit 53 uses the control theory based on feedback such as open loop or PID so that the adjustment amount of the pressure adjusting devices 41 and 45 is adjusted so that the pressure values detected by the pressure sensors 47 and 50 are within a predetermined range. I have control. Of course, the arrangement of the pressure sensors 47 and 50 is not limited to this, and the pressure sensors 47 and 50 can be directly provided in the nozzle or the hermetic chamber, whereby the pressure propagation paths 48, 49, 51 and 52 can be omitted, and the pressure response time is further shortened. Therefore, it is more advantageous in terms of pressure control.

  On the other hand, an inert gas supply device 55 is connected to the load lock chamber 13 via a supply path 54. A pressure adjusting device 56 and a valve 57 for adjusting the supply pressure of the inert gas are provided in the middle of the supply path 54. Is provided and connected to the control unit 53. The inert gas supplied from the supply path 54 is uniformly supplied to the load lock chamber 13 through the perforated plate 62. Further, an inert gas suction device 59 is connected to the load lock chamber 13 via a discharge path 58, and a pressure adjusting device 60 and a valve 61 for adjusting the discharge pressure of the inert gas are provided in the middle of the discharge path 58. Provided and connected to the control unit 53. The inert gas discharged from the discharge path 58 is uniformly discharged from the load lock chamber 13 through the perforated plate 63. Further, a pressure sensor 64 for measuring the pressure value in the load lock chamber 13 is provided, and a detection signal thereof is sent to the control unit 53. If the pressure sensor 47 or the pressure sensor 50 detects the pressure value in the load lock chamber 13, they can be used instead of the pressure sensor 64. Until the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are brought into close contact with the end surface of the pellicle frame of the loaded reticle 23, the supply of the inert gas from the supply path 54 and the discharge from the discharge path 58 are performed by using the valves 57 and 61. Since it is in a closed and stopped state, the inside of the load lock chamber 13 is almost at atmospheric pressure until this point. As described above, the control unit 53 opens the valves 42 and 46 and starts controlling the supply pressure of the supply nozzle 33 and the discharge pressure of the discharge nozzle 35. Thereafter, the supply pressure of the supply path 54 is controlled by the pressure adjusting device 56 so that the pressure in the load lock chamber 13 is increased to a specified value (for example, 2 atmospheres), and the discharge pressure from the discharge path 58 is controlled by the pressure adjusting device 60. To control. As a result, the inside of the load lock chamber 13 reaches a specified pressure, and the inert gas is supplied and mixed with the original air and discharged, so that the concentration of the exposure light absorbing material such as oxygen and moisture decreases. To go.

  At this time, the control unit 53 supplies the pressure adjusting devices 41 and 45 while controlling the absolute values of the relative pressure values of the supply nozzle 37 and the discharge nozzle 38 with respect to the load lock chamber 13 to be within the allowable value. The relative pressure value in the nozzle inside 37 is increased and the relative pressure value in the discharge nozzle 38 is decreased. However, when the pressure in the load lock chamber 13 is 2 atm, for example, the discharge pressure from the discharge nozzle 35 is set to 0. When the pressure is reduced to 5 atmospheres, the differential pressure is 1.5 atmospheres, so the supply pressure to the supply nozzle 33 is increased to 3.5 atmospheres. If the pressure in the load lock chamber 13 remains at 1 atm, the differential pressure is 0.5 atm. Therefore, the differential pressure is three times as high as that, so that the inert gas supplied to the pellicle space 20 and discharged is discharged. The flow rate is greatly increased accordingly, and the purge time of the pellicle space 20 is greatly shortened.

  In this state, after a predetermined time required for purging obtained in advance in an experiment has elapsed, the control unit 53 uses the pressure adjusting devices 41 and 45 to cause the relative pressure values of the supply nozzle 37 and the discharge nozzle 38 to be relative to the load lock chamber 13. The relative pressure value in the supply nozzle 33 is decreased, the relative pressure value in the discharge nozzle 38 is increased, and the differential pressure between the two is zero. To control. Thereafter, or simultaneously, the pressure in the load lock chamber 13 is controlled to be the same as the pressure in the reticle purge chamber space 21. Then, the valves 42 and 46 are closed to stop the supply from the supply nozzle 33 and the discharge from the discharge nozzle 35, and the valves 57 and 61 are closed to supply the inert gas from the supply path 54 and discharge from the discharge path 58. To stop. Next, after the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are separated from the end surfaces of the pellicle frame, the inner door 29 is opened. The reticle 23 is carried from the load lock chamber 13 into the reticle purge chamber space 21 by the reticle hand 15 in the reticle purge chamber space 21, and the inner door 29 is closed. The reticle 23 is conveyed by the reticle hand 15 to either the reticle stage 1 or the reticle storage 18 or the foreign matter inspection apparatus 90.

  In the present embodiment, when the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are brought into close contact with the end surface of the pellicle frame of the loaded reticle 23, the supply nozzle proximity mechanism 34 and the discharge nozzle proximity mechanism 36 are positioned at predetermined positions. Although alignment is performed, it is more preferable to provide a sensor for measuring a gap between the end surfaces of the supply nozzle 33 and the discharge nozzle 35 and the end surface of the pellicle frame so as to bring them into close contact with each other more accurately. Alternatively, instead of measuring the gap, while supplying and discharging a fixed amount of inert gas from the supply nozzle 33 and the discharge nozzle 35, the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are driven closer to the end surface of the pellicle frame, and the pressure sensor By measuring the pressures in the supply nozzle 37 and the discharge nozzle 38 by 47 and 50 and determining the end of driving based on the pressure value or the amount of change in pressure, it is possible to align the positions more closely. Leakage can be reduced if the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are brought into close contact with the end surface of the pellicle frame, so that the pellicle space 20 can be efficiently replaced with an inert gas. However, since the pellicle frame 25 is attached to the reticle 23 with an adhesive, if the pellicle frame 25 is greatly deformed by applying a large force to the pellicle frame 25, the pellicle frame 25 may not be completely restored. It is desirable that the end face of the nozzle 35 is brought into close contact with the above-described alignment so as not to apply a force exceeding the allowable value to the end face of the pellicle frame. In particular, when the pellicle film 26 is a hard pellicle, since its thickness is about 0.8 mm, for example, the deformation sensitively affects the optical performance. It is desirable to make them close together. Therefore, one or a plurality of displacement meters that optically or electrically detect the deformation of the pellicle film 26, the pellicle frame 25, or the reticle 23 are provided, and the displacement is supplied so as to be less than a predetermined allowable value. It is desirable to control the positioning of the nozzle 33 and the discharge nozzle 35. Alternatively, leakage may be allowed to some extent, and the end surfaces of the supply nozzle 33 and the discharge nozzle 35 may be opposed to the end surfaces of the pellicle frame without providing close contact. However, the gap on the supply nozzle 33 side and the gap on the discharge nozzle 35 side are substantially the same, and the flow path resistance is substantially the same.

  In the above embodiment, the total amount of the channel resistance at all the supply ports a and the total amount of the channel resistance at all the discharge ports b including the channel resistances of the dust removal filters 31 and 32 are substantially the same. Even when the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are opposed to each other without being in close contact with the end surface of the pellicle frame, the gap between the two is made substantially the same, and the flow resistance is made almost the same. did. However, even when the flow path resistances on the supply side and the discharge side are different from each other, the pressure may be adjusted by giving a pressure difference between the supply nozzle 37 and the discharge nozzle 38 in accordance with the ratio. For example, when the flow path resistance on the supply side is high, the absolute value of the relative pressure value in the supply nozzle 37 is made larger than the absolute value of the relative pressure value in the discharge nozzle 38. To what extent the pellicle film 26 should not be deformed may be obtained in advance by experiments.

[Second Embodiment]
FIG. 4 is a diagram showing a second embodiment of the present invention. In the first embodiment, the pressure difference between the supply nozzle 33 and the discharge nozzle 35 and the load lock chamber 13 is measured, and the supply pressure and discharge pressure of the inert gas are controlled so that they are the same. However, in this embodiment, one or more displacement meters 65 for optically or electrically detecting deformation of the pellicle film 26, the pellicle frame 25, or the reticle 23 are provided instead. However, since the amount of deformation is the largest at the center of the pellicle film 26, it is desirable to provide a displacement meter 65 so as to measure the amount of deformation z at the center as shown in FIG. Then, the control unit 53 controls the relative pressure value with respect to the load lock chamber 13 in the supply nozzle 37 or the discharge nozzle 38 so that the displacement amount of the deformation amount z is not more than a predetermined allowable value. The relative pressure value inside the nozzle 37 is gradually increased, and the relative pressure value inside the discharge nozzle 38 is gradually lowered. At that time, when the load lock chamber 13 is pressurized by the pressure adjusting devices 56, 60, the pellicle space 20 is also pressurized so as not to deform the pellicle film 26.

  Alternatively, the controller 53 does not use the pressure sensor 47 or the pressure sensor 50, but gradually increases the pressure value in the supply nozzle 37 by the pressure adjustment device 41, and increases the pressure value in the discharge nozzle 38 by the pressure adjustment device 45. It is also possible to control the pressure value in the load lock chamber 13 so that the amount of displacement becomes lower than a predetermined allowable value at the same time as it is gradually lowered. At this time, the degree of increasing the pressure value in the supply nozzle 37 is greater than the degree of decreasing the pressure value in the discharge nozzle 38, so that the pressure values in the load lock chamber 13 and the pellicle space 20 become higher than the atmospheric pressure. Like that.

  In any case, since the differential pressure between the supply nozzle 37 and the discharge nozzle 38 with respect to the pellicle space 20 can be increased, the flow rate of the inert gas supplied to and discharged from the pellicle space 20 is greatly increased, and the pellicle space 20 is purged. Time will be shortened. If the displacement of the pellicle film 26 is directly measured and controlled in this way, there may be a difference in the total amount of flow path resistance at the air supply port a and the exhaust port b, including individual differences. Even if the end face of the discharge nozzle 35 and the end face of the pellicle frame are not in close contact with each other and leakage occurs and there is a difference in the flow resistance, there is no problem, and the end face of the supply nozzle 33 and the discharge nozzle 35 and the end face of the pellicle frame are slightly There is a unique effect that there may be variations in the gaps when providing such gaps.

  In the above-described embodiment, an example in which the pellicle space 20 is purged in the load lock chamber 13 has been described. However, a place for arranging a mechanism for purging the pellicle space 20 including the supply nozzle 33 and the discharge nozzle 35 is provided. Is not limited to the load lock chamber 13. It can be provided in a reticle storage and a pellicle inspection machine, or can be provided as a dedicated room for pellicle purging in the reticle transport path in the reticle purge chamber space 21. In addition, it is not limited to any one place, but it is also possible to place multiple places and automatically select and carry out inert gas purging at the optimum place according to the reticle usage plan. .

  In the first and second embodiments, the supply nozzle 33 and the discharge nozzle 35 are connected to the load lock chamber 13 when facing the end surfaces of the pellicle frame with a slight gap therebetween. It is also possible to simplify the device configuration by eliminating the inert gas supply device 55 and the inert gas suction device 59. That is, the inert gas leaks from the supply nozzle 33 into the load lock chamber 13, while the gas in the load lock chamber 13 leaks into the discharge nozzle 35 and is discharged, so that the purge in the load lock chamber 13 is also performed. If the purge in the load lock chamber 13 is insufficient by itself, the inert gas is supplied by the supply nozzle 33 and the discharge nozzle 35 before or after the end surfaces of the supply nozzle 33 and the discharge nozzle 35 face the end surface of the pellicle frame. It is possible to sufficiently purge the load lock chamber 13 by supplying and discharging the gas.

[Third embodiment]
FIG. 5 is a diagram showing a third embodiment of the present invention. In the above-described embodiment, the purge efficiency of the pellicle space 20 is increased by pressurizing the entire load lock chamber 13, but in this embodiment, a pellicle pressurizing chamber 66 is provided instead and only the pellicle film 26 is added. I tried to press. That is, a pellicle pressurizing chamber 66 is provided in place of the support base 30 of the first and second embodiments, the loaded reticle 23 is positioned, and the lower surface of the pellicle frame 25 is above the pellicle pressurizing chamber 66. It is placed in contact with. At this time, the contact surface of the pellicle pressurizing chamber 66 has the same shape as that of the pellicle frame 25 and becomes a sealed space by being blocked by the pellicle film 26. The contact surface of the pellicle pressurizing chamber 66 may be an elastic body such as rubber or resin in order to improve sealing performance, or may be vacuum-sucked by providing a vacuum suction groove. An inert gas supply device 68 is connected to the pellicle pressurizing chamber 66 through a supply path 67. A pressure adjusting device 69 and a valve 70 for adjusting the supply pressure of the inert gas are provided in the supply path 67. Provided and connected to the control unit 53. An inert gas suction device 72 is connected via a discharge path 71, and a pressure adjusting device 73 and a valve 74 for adjusting the discharge pressure of the inert gas are provided in the middle of the discharge path 71. It is connected to the. As in the second embodiment, one or a plurality of displacement meters 65 for optically or electrically detecting the deformation of the pellicle film 26 are provided, and the control unit 53 has an allowable value with a predetermined amount of displacement. While controlling the relative pressure value of the supply nozzle 37 or the discharge nozzle 38 with respect to the pellicle pressurizing chamber 66, the relative pressure value of the supply nozzle 37 is gradually increased so that Gradually lower the relative pressure value. At this time, when the pellicle pressurizing chamber 66 is pressurized by the pressure adjusting devices 69 and 73, the pellicle space 20 is also pressurized so as not to deform the pellicle film 26.

Alternatively, the controller 53 does not use the pressure sensor 47 or the pressure sensor 50, but gradually increases the pressure value in the supply nozzle 37 by the pressure adjustment device 41, and increases the pressure value in the discharge nozzle 38 by the pressure adjustment device 45. It is also possible to control the pressure value in the pellicle pressurizing chamber 66 so that the amount of displacement is not more than a predetermined allowable value at the same time as it is gradually lowered. At this time, the degree of increasing the pressure value in the supply nozzle 37 is set higher than the degree of decreasing the pressure value in the discharge nozzle 38, so that the pressure values in the pellicle pressurizing chamber 66 and the pellicle space 20 are higher than the atmospheric pressure. To be.
In any case, since the differential pressure between the supply nozzle 37 and the discharge nozzle 38 with respect to the pellicle space 20 can be increased, the flow rate of the inert gas supplied to and discharged from the pellicle space 20 is greatly increased, and the pellicle space 20 is purged. Time will be shortened.

  Also in this embodiment, the place where the mechanism for purging the pellicle space 20 is disposed may be in the load lock chamber 13 or is not limited to the load lock chamber 13. In particular, in the case of arranging in a reticle storage for storing a large number of reticles or in a reticle transport path, a room for sealing around the reticle 23 becomes unnecessary, which is preferable because the space is reduced. However, in this case, since the pressure around the reticle 23 cannot be pressurized, the upper surface side of the reticle 23 is not pressurized and only the lower surface side is pressurized, and a differential pressure is generated. Therefore, the reticle 23 is peeled off from the pellicle frame 25. Receive. Since the pellicle frame 25 is affixed to the reticle 23 with an adhesive, there is a possibility that if the reticle 23 is largely deformed by applying a large force to the reticle 23, it cannot be completely restored. . Therefore, during the pressurization of the pellicle space 20, it is possible to increase the pressure by preventing the reticle 23 from being deformed by pressing the upper surface of the reticle with a reticle pressing mechanism (not shown), thereby further purging the pellicle space 20. There is an effect that time is shortened. Note that the reticle pressing mechanism may be structured so as to serve also as a reticle hand for transporting the reticle 23.

  In this embodiment, the displacement meter 65 is used to control the deformation of the pellicle film 26. However, the displacement meter 65 may not be used. That is, while measuring the pressure difference in the supply nozzle 33 and the discharge nozzle 35 and the pellicle pressurizing chamber 66 in FIG. 5 and controlling the supply pressure and discharge pressure of the inert gas so that they are the same, The relative pressure value in the supply nozzle 37 is gradually increased, and the relative pressure value in the discharge nozzle 38 is gradually decreased. At this time, since the pressure loss at the supply port a and the supply port b is substantially the same, the pellicle film 26 is hardly deformed. When the pellicle pressurizing chamber 66 is pressurized by the pressure adjusting devices 69 and 73, the pellicle space 20 is also pressurized, and the differential pressure between the supply nozzle 37 and the discharge nozzle 38 with respect to the pellicle space 20 can be increased. As a result, the flow rate of the inert gas supplied to the exhaust gas 20 is greatly increased, and the purge time of the pellicle space 20 is shortened.

  In this embodiment, as in the first embodiment, leakage is allowed to some extent, and the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are not brought into close contact with the end surface of the pellicle frame, but are allowed to face each other. Also good. At this time, when the displacement meter 65 is not used, the gap on the supply nozzle 33 side and the gap on the discharge nozzle 35 side are made substantially the same, and the flow path resistances are made almost the same.

[Fourth embodiment]
FIG. 6 is a diagram showing a fourth embodiment of the present invention. The pellicle pressurizing chamber 66 is provided with a supply port c and a discharge port d, and dust removing filters 77 and 78, and a supply nozzle 79 and a discharge nozzle 80 are provided in close contact with each other. At that time, the total amount of the channel resistance at the supply port c including the channel resistance of the dust filter 77 is substantially the same as that of the supply port a of the pellicle frame 25 and includes the channel resistance of the dust filter 78. The total amount of channel resistance at the outlet d is substantially the same as that of the outlet b of the pellicle frame 25. The supply nozzle 33 and the supply nozzle 79 are both connected to the supply path 39, and the discharge nozzle 35 and the discharge nozzle 80 are both connected to the discharge path 43.

  Then, as shown in FIG. 6, the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are brought into close contact with the end surface of the pellicle frame 25 of the loaded reticle 23, and the pressure values in the supply nozzles 37 and 81 are gradually increased by the pressure adjusting device 41. The pressure adjustment device 45 gradually lowers the pressure values in the discharge nozzles 38 and 82. At this time, since the total amount of flow path resistance at the supply port c and the discharge port d is substantially the same as that of the supply port a and the discharge port b of the pellicle frame 25, respectively, the pellicle space 20 and the pellicle pressurizing chamber 66 are used. Are almost the same, and the pellicle film 26 is hardly deformed. Then, the pressure value in the pellicle pressurizing chamber 66 and the pellicle space 20 is increased by making the pressure value in the supply nozzles 37 and 81 higher than the degree in which the pressure values in the discharge nozzles 38 and 82 are lowered. Be higher than atmospheric pressure. As a result, the differential pressure between the supply nozzle 37 and the discharge nozzle 38 with respect to the pellicle space 20 can be increased, so that the flow rate of the inert gas supplied to and discharged from the pellicle space 20 is greatly increased, and the purge time of the pellicle space 20 is increased. It will be shortened. Further, there is a need for a pressure sensor and a displacement meter, a single inert gas supply system and exhaust system are required, and the control is simplified.

  In the present embodiment, as in the first embodiment, leakage is allowed to some extent, and the end surfaces of the supply nozzle 33 and the discharge nozzle 35 are made to face each other with a slight gap without being in close contact with the end surface of the pellicle frame. Also good. In that case, the end face of the supply nozzle 79 is opposed to the supply port c without providing a slight gap, and the end face of the discharge nozzle 80 is provided to face the discharge port d without contacting the discharge port d. At that time, the gap between the supply nozzle 33 and the gap between the supply nozzle 79 are made substantially the same, the gap between the discharge nozzle 35 and the gap between the discharge nozzles 80 are made almost the same, and the flow path resistance is made almost the same.

  Also in the present embodiment, as in the third embodiment, there is a possibility that pressurization can be performed because there is a possibility that the reticle 23 cannot be completely restored if a large force is applied to the reticle 23 to greatly deform it. Therefore, during the pressurization of the pellicle space 20, it is possible to increase the pressure by preventing the reticle 23 from being deformed by pressing the upper surface of the reticle with a reticle pressing mechanism (not shown), thereby further purging the pellicle space 20. There is an effect that time is shortened. Further, the reticle pressing mechanism may have a structure that also serves as a reticle hand that conveys the reticle 23.

In the first to fourth embodiments described above, the pellicle space 20 is continuously purged until a predetermined time elapses. However, an impurity concentration that detects the impurity concentration in the inert gas is located in the middle of the inert gas discharge path 43. A sensor 75 is provided to detect the impurity concentration of the gas discharged from the pellicle space 20 by the discharge nozzle 35, and the purge is terminated when the impurity concentration is equal to or lower than a preset allowable value. In this way, it is possible to reliably replace the pellicle space 20 with a predetermined inert gas concentration, and there is an advantage that it is not necessary to increase the replacement time more than necessary in anticipation of safety. The impurity concentration sensor 75 includes, for example, one or both of an oxygen concentration sensor and a moisture concentration sensor. Further, if an atmospheric pressure ionization sensor that ionizes impurities such as H ₂ O, O ₂ , CO ₂ , and organic substances in an inert gas to detect impurities with high sensitivity, the total amount of impurities can be detected. Therefore, there is an advantage that the inert gas concentration can be detected more strictly.

  In the above embodiment, the inert gas supplied to the pellicle space 20 and the load lock chamber 13 or to the pellicle pressurizing chamber 66 uses a high-purity impurity having an impurity concentration of, for example, 1 ppm or less, thereby purging time. However, it is also possible to use an inert gas which is controlled not to have a high purity but to a concentration almost the same as the impurity concentration in the inert gas in the space of the reticle purge chamber 21 (housing 8). For example, when the oxygen concentration in the reticle purge chamber 21 space is 50 ppm, the oxygen concentration of the inert gas supplied to the pellicle space 20 and the load lock chamber 13 or the pellicle pressurizing chamber 66 is also controlled to approximately 50 ppm. That is, an oxygen supply device for mixing a small amount of oxygen is connected to the outlets of the inert gas supply devices 40, 55, and 68, and an oxygen concentration meter is connected thereafter, so that it always becomes 50 ppm. This is possible by controlling the amount of oxygen supplied from the oxygen supply device. When purging is performed in this manner, the impurity concentration in the pellicle space 20 and the load lock chamber 13 or the pellicle pressurizing chamber 66 and the reticle purge chamber space 21 becomes the same. When the load lock chamber 13 and the reticle purge chamber space 21 are communicated with each other, or when the reticle 23 is unloaded from the pellicle pressurizing chamber 66, it is possible to prevent the impurity concentration in the reticle purge chamber space 21 from fluctuating. There is a specific effect that the impurity concentration in the pellicle space 20 can be prevented from fluctuating and the exposure light absorption rate, that is, the exposure amount can be prevented from fluctuating.

  In the above embodiment, the dust filter of the pellicle frame 25 is provided outside the supply port a and the discharge port b. However, as shown in FIG. 7, the dust filter is provided inside the supply port a and the discharge port b. If provided, it is possible to increase the area where the supply nozzle 33 and the discharge nozzle 35 can be brought into close contact with each other. In addition, as shown in FIG. 8, it is desirable to provide a dust filter on the outside of the supply port a and the inside of the discharge port b because the dust filter can be prevented from being peeled off by the pressure of the inert gas. Further, as shown in FIG. 9, dust filters may be provided at two locations inside and outside the supply port a and the discharge port b, respectively, to improve the dust removal capability, or inside the supply port a and the discharge port b. May be filled. In addition, when the dust removal filter is provided outside the supply port a and the discharge port b as in the above-described embodiment, if the supply nozzle 33 and the discharge nozzle 35 can be brought into close contact with the end surface of the pellicle frame, Even the pellicle provided inside the supply port a and the discharge port b can be used as it is.

  In the above embodiment, the supply port a and the discharge port b of the pellicle frame 25 are provided on the two long sides of the pellicle frame 25, but may be provided on the two short sides. In addition, a supply nozzle and an exhaust nozzle may be arranged. Alternatively, it may be provided on all four sides of the pellicle frame 25. For example, a supply port a is additionally provided on the upper side of the pellicle frame 25 in FIG. 1, and a discharge port b is additionally provided on the lower side. Additional nozzles may be arranged. As a result, the supply amount and the exhaust amount of the inert gas can be doubled, and the purge time of the pellicle space 20 can be further shortened.

As described above, according to the exposure apparatus of the present embodiment, in the exposure apparatus using ultraviolet rays, particularly fluorine (F ₂ ) excimer laser light, the purge time of the pellicle space when carrying the reticle can be significantly shortened. In addition to shortening the time to carry in the reticle and improving productivity, it is possible to obtain high transmittance of fluorine (F ₂ ) excimer laser light and temporal and spatial uniformity of transmittance within the screen. It was. This makes it possible to obtain a high illuminance of the exposure light that reaches the wafer, minimizing the illuminance unevenness in the screen, making it possible to perform projection exposure quickly and with high accuracy, and a fine circuit pattern. Can be projected well.

The exposure apparatus of the present invention is not limited, and is an exposure apparatus that transfers a pattern of an original to a photosensitive substrate via a projection optical system, and can be applied to a known one as long as the original has a pellicle.
However, the present invention is particularly suitable when applied to an exposure apparatus that uses ultraviolet light as exposure light. Moreover, the present invention is effective for ultraviolet (F ₂ ) excimer laser light having a wavelength near 157 [nm] in the vacuum ultraviolet region, among ultraviolet light.

[Fifth embodiment]
Next, a semiconductor device manufacturing process using this exposure apparatus will be described.
FIG. 13 shows a flow of manufacturing a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.).
In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask production), a mask on which the designed pattern is formed is produced.
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 wafer and the exposure apparatus provided with the prepared mask.
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. A semiconductor device is completed through these processes, and is shipped in Step 7.

  The wafer process in step 4 includes the following steps. An oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, an electrode formation step for forming electrodes on the wafer by vapor deposition, an ion implantation step for implanting ions on the wafer, and applying a photosensitive agent to the wafer The resist processing step, the exposure step for printing and exposing the circuit pattern onto the wafer after the resist processing step by the above-described exposure apparatus, the development step for developing the wafer exposed in the exposure step, and the etching for removing portions other than the resist image developed in the development step Step, resist stripping step to remove resist that is no longer needed after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

It is a schematic block diagram of the reticle load lock chamber of the projection exposure apparatus according to the first embodiment of the present invention. It is a figure which shows the cross section of the reticle load lock chamber of FIG. 1, and the structure of a gas supply and discharge system. FIG. 2 is a cross-sectional view of the reticle load lock chamber of FIG. 1 showing a pellicle space purge operation state. It is sectional drawing of the reticle load-lock chamber of the projection exposure apparatus which concerns on 2nd Example of this invention. It is sectional drawing of the pellicle space purge mechanism of the projection exposure apparatus which concerns on 3rd Example of this invention. It is sectional drawing of the pellicle space purge mechanism of the projection exposure apparatus which concerns on the 4th Example of this invention. It is a schematic block diagram of the pellicle stuck on the reticle. It is a schematic block diagram of the pellicle stuck on the reticle. It is a schematic block diagram of the pellicle stuck on the reticle. It is a schematic block diagram which shows the principal part of the step and scan type | mold projection exposure apparatus which is a prior art example and is also an example of the application object of this invention. It is a schematic block diagram which shows the prior art example of the pellicle stuck on the reticle. It is a schematic block diagram which shows the reticle conveyance path | route especially of the projection exposure apparatus with which this invention is applied preferably. It is a figure explaining the flow of the manufacturing process of a device.

Explanation of symbols

1: reticle stage, 2: lens barrel, 3: wafer stage, 4: illumination optical system, 5: routing optical system, 6: F ₂ laser unit, 7: masking blade, 8, 9: casing, 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: Pellicle space, 21: Reticle purge chamber, 23: Reticle, 24: Pellicle, 25: Pellicle frame, 26: Pellicle membrane, 27: Vent hole, 28: Outside door, 29: Inside door, 30: Support base, 31, 32: Dust filter, 33, 79: Supply nozzle, 34, 36: Nozzle proximity mechanism, 35, 80: Exhaust nozzle, 37, 81: In supply nozzle, 38, 8 2: inside the exhaust nozzle, 39, 54: supply path, 40, 55, 68: inert gas supply device, 41, 45, 56, 60, 69, 73: pressure adjusting device, 42, 46, 57, 61, 70 74, valve, 43, 58, 67, 71: discharge path, 44, 59, 72: inert gas suction device, 47, 50, 72: pressure sensor, 48, 49, 51, 52, 64: pressure propagation path 53: Control unit, 62, 63: Perforated plate, 65: Displacement meter, 66: Pellicle pressurizing chamber, 75: Impurity concentration sensor, 77, 78: Dust filter, 90: Foreign substance inspection device, a, c: Supply port , B, d: outlet

Claims (10)

An exposure apparatus for transferring a pattern of an original plate having a pellicle comprising a pellicle film and a pellicle frame having one or more supply ports and one or more discharge ports to a photosensitive substrate,
A supply nozzle for supplying an inert gas opposite to the supply port;
A nozzle proximity mechanism for bringing the supply nozzle close to or close to the supply port;
A discharge nozzle for discharging gas opposite to the discharge port;
A nozzle proximity mechanism for bringing the discharge nozzle close to or close to the discharge port;
Surrounding means for enclosing at least the outside of the pellicle film of the original plate;
Means for supplying an inert gas into the surrounding means;
Means for discharging gas from within the surrounding means;
Controlling at least one of the pressure of the inert gas supplied to the supply nozzle and the pressure of the gas discharged from the discharge nozzle, and the pressure of the inert gas supplied into the surrounding means and the pressure of the gas discharged from the surrounding means Pressure control means to
An exposure apparatus comprising:   2. The exposure apparatus according to claim 1, wherein the surrounding means is a load lock chamber having one or more doors.   2. The exposure apparatus according to claim 1, wherein the surrounding means is a pellicle pressurizing chamber that forms a sealed space on the pellicle film.   The exposure according to any one of claims 1 to 3, wherein the pressure control means controls the gas pressures so that the pressure difference between the inside and the outside of the pellicle film is the same or substantially the same. apparatus.   The pressure control means includes means for detecting a pressure outside the pellicle film and a pressure or a pressure difference in the supply nozzle and in the discharge nozzle, and a pressure outside the pellicle film and in the supply nozzle and the discharge 5. The exposure apparatus according to claim 4, wherein the gas pressures are controlled so that the absolute values of the pressure differences with the nozzles are the same or substantially the same.   The pressure control means includes means for detecting deformation of the pellicle film, and controls each gas pressure so that the deformation of the pellicle film is minimized. The exposure apparatus according to one.   The total amount of channel resistance of the supply port of the pellicle frame and the total amount of channel resistance of the supply port of the surrounding means are the same or substantially the same, and the total amount of channel resistance of the discharge port of the pellicle frame and the amount of the surrounding means The exposure apparatus according to claim 1, wherein the total amount of flow path resistance of the discharge port is the same or substantially the same.   The total amount of channel resistance of the supply port of the pellicle frame and the total amount of channel resistance of the supply port of the surrounding means are the same or substantially the same, and the total amount of channel resistance of the discharge port of the pellicle frame and the amount of the surrounding means The total amount of flow path resistance of the discharge port is the same or substantially the same, the supply port of the pellicle frame and the supply port of the surrounding means are in a common supply path, the discharge port of the pellicle frame and the discharge port of the surrounding means 4. The exposure apparatus according to claim 3, wherein and are connected to a common discharge path.   9. The exposure apparatus according to claim 8, wherein a volume of the pellicle pressurizing chamber and a volume of a space surrounded by the pellicle frame, the pellicle film, and the original plate are the same or substantially the same.   A device manufacturing method comprising: a step of exposing a substrate using the exposure apparatus according to claim 1; and a step of developing the exposed substrate.

Images