JP2011070009A - Degassing device for pellicle and degassing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce outgas from a pellicle and gas adsorbing onto the pellicle from the environment during storage. <P>SOLUTION: A degassing device for a pellicle is provided, including a chamber 3 holding a pellicle 1 inside, a gas inlet system 5 introducing an atmospheric gas into the chamber 3, and a controller 7 controlling the gas inlet system 5 so as to adjust the atmospheric gas to a required gas flow rate and required gas pressure and to introduce the gas into the chamber 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pellicle degassing apparatus and a degassing method for reducing outgas discharged from a pellicle and gas adsorbed from a storage environment.

  In the photolithography process, which is one of the manufacturing processes of semiconductor elements and liquid crystal display elements, a photomask is used as a circuit original plate, which is patterned on the glass plate surface by vapor deposition of chromium, molybdenum, silicon, and oxides and nitrides thereof. ing. The photomask is irradiated with light, and a circuit pattern is transferred onto a resist-coated silicon wafer or liquid crystal plate.

  However, if foreign matter adheres to the photomask during light irradiation, absorption, scattering, and diffraction of the irradiation light occur, and a circuit pattern different from the formed mask pattern is transferred onto the silicon wafer or liquid crystal plate. There is a problem that causes a decrease in the yield of products.

  Therefore, in the photomask manufacturing process, after the photomask is washed to make it free from foreign matter, the pattern is covered with a pellicle which is a so-called foreign matter protection jig that transmits light of a target wavelength to the photomask. Has been done.

  A conventional general pellicle is a frame made of a metal such as aluminum and its oxide, and an adhesive made of acrylic resin or fluoropolymer, and a membrane (pellicle film) made of cellulose or fluoropolymer adhered. The pellicle is bonded to the photomask with an adhesive made of acrylic resin or silicone resin.

  By the way, in recent years, in semiconductor elements such as LSI, as the pattern becomes finer, the exposure wavelength of lithography changes from g-line (436 nm) to i-line (365 nm), krF excimer laser (248 nm), ArF excimer laser (193 nm). The trend is toward shorter wavelengths.

  However, when the exposure wavelength is shortened, the irradiation energy increases, and the chemical reaction of various substances existing on the photomask and the pellicle or in the space surrounded by the photomask and the pellicle is promoted, so that a growing foreign substance Produces. Such a growth foreign material aggregated on a photomask and a pellicle is called a spider or haze and is regarded as a very problem from the viewpoint of patterning. In particular, in the excimer laser, oxygen present in the exposure atmosphere is changed to ozone, so that the oxidation reaction of various substances is promoted and the quality of the photomask is remarkably deteriorated.

  Therefore, conventionally, there has been proposed a technique for reducing the outgas from the pellicle member that may cause haze by providing a lower limit (Patent Document 1).

  An exposure apparatus having a unit capable of gas replacement of the entire photomask with pellicle and an exposure method therefor have been proposed. This exposure apparatus and exposure method is a method in which the space on the photomask and pellicle or the space surrounded by the photomask and pellicle is always purged with an inert gas even during exposure (Patent Document 2).

JP 2007-333910 A JP 2002-196478 A

  By the way, according to the technique described in Patent Document 1, since the outgas of the pellicle member itself is reduced, it becomes an effective means for suppressing haze, but in the process atmosphere when the pellicle member is stored in the photomask manufacturing process. Therefore, it is impossible to control the newly adsorbed gas component.

  In addition, in the technique described in Patent Document 2, it is difficult to completely replace a chemical substance having affinity and adsorptivity with a pellicle member or a photomask member with an inert purge gas, and the development and modification of the apparatus are costly. Therefore, it has not yet reached the practical range. As a result, the growing foreign matter on the photomask and the pellicle is not eradicated.

  Therefore, in order to remove the generated growth foreign matter, it is necessary to peel the pellicle from the photomask and clean the photomask.

  The above operations have a problem in that the production capacity in the manufacturing process of the semiconductor element and the liquid crystal display element is lowered, and further, the manufacturing cost is increased.

  The present invention has been made in view of the above circumstances, and a degassing device for a pellicle that reliably degass and reduces outgas generated from the pellicle member and adsorbed gas adsorbed from the environment when the pellicle member is stored, and its degassing. It aims to provide a method.

  In order to solve the above-described problems, the present invention requires a chamber for holding a pellicle therein, a gas introduction system for introducing an atmospheric gas into the chamber, and controlling the gas introduction system to thereby supply the atmospheric gas. A controller that adjusts the gas flow rate and the required gas pressure to introduce the gas into the chamber, heats the pellicle through the chamber that holds the pellicle inside, and absorbs gas out of the pellicle and gas adsorbed from the environment when the pellicle member is stored. This is a degassing device for a pellicle to be detached.

  The pellicle degassing apparatus according to the present invention has a heat source for heating the chamber, and includes a heating means for controlling the gas temperature of the pellicle and the atmospheric gas in the chamber by the control command of the controller or itself. In addition, it is configured to degas outgas from the pellicle and gas adsorbed from the environment during storage.

  A pellicle holding jig for holding the pellicle is accommodated in the chamber. The pellicle holding jig has a plurality of shelves on which the pellicle is placed, and a ventilation window is formed in each shelf.

  The gas introduction system includes a gas feed pipe for sending atmospheric gas into the chamber, and a gas flow rate of the atmosphere gas that is installed in the gas feed pipe and flows through the gas feed pipe under the control command of the controller. And a gas introduction unit for controlling the gas pressure, and an atmosphere gas having a stable gas flow rate and gas pressure is supplied from the gas introduction unit to the chamber.

  In the pellicle degassing apparatus according to the present invention, a gas exhaust system for exhausting atmospheric gas in the chamber is connected to the chamber. This gas exhaust system includes a gas exhaust pipe for exhausting atmospheric gas in the chamber to the outside, and a gas flow rate and gas pressure of the atmospheric gas installed in the gas exhaust pipe and exhausted under the control command of the controller. A gas exhaust unit to be controlled, and the atmosphere exhaust gas having a stable gas flow rate and gas pressure is exhausted to the outside from the gas exhaust unit.

  The pellicle degassing apparatus according to the present invention is provided with a filter in the gas feed pipe on the downstream side of the gas introduction unit to remove foreign substances and chemical pollutants existing in the atmospheric gas. .

  Next, the pellicle degassing method according to the present invention is supplied in the holding step of holding the pellicle in the chamber, the gas supply step of supplying atmospheric gas into the chamber holding the pellicle, and the gas supply step. And after the atmosphere gas is replaced in the chamber, the pellicle in the chamber and the heating step for controlling the atmosphere gas to have a predetermined temperature are included, and the outgas from the pellicle and the gas adsorbed from the environment during storage This is a method of degassing.

  In the gas supply step, foreign substances and chemical contaminants present in the atmospheric gas are removed, and the gas is supplied into the chamber holding the pellicle.

  The atmosphere gas is characterized by being an inert gas such as N2 and rare gas, an active gas such as O2 and H2O, and air.

  In this degassing method of the pellicle, the atmospheric gas supplied into the chamber holding the pellicle is controlled to have a required gas flow rate and gas pressure, while the atmospheric gas in the chamber is externally supplied at the required flow rate and pressure. It is characterized by exhausting.

  Also, in the degassing method of the pellicle, a pellicle holding jig in which the pellicle is placed on each shelf provided with a ventilation window is accommodated in the chamber, and the space between the pellicle and the shelf is set to be in a ventable state. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the degassing apparatus and degassing method of a pellicle which can reduce the outgas from a pellicle and the gas adsorb | sucked from an environment at the time of pellicle member storage can be provided.

The block diagram which shows one Embodiment of the degassing apparatus of the pellicle which concerns on this invention. The figure which shows the example of 1 structure of a pellicle. The figure which shows the example of 1 structure of a pellicle holding jig.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of a pellicle degassing apparatus according to the present invention.

  The pellicle degassing apparatus includes a chamber 3 that houses a pellicle holding jig 2 that holds the pellicle 1, a heating device 4 for heating the chamber 3, a gas introduction system 5, a gas exhaust system 6, and the like. It comprises a heating device 4, a gas introduction system 5, and a controller 7 that controls the gas exhaust system 6.

  The chamber 3 has a structure capable of holding the pellicle holding jig 2 holding the pellicle 1. For example, a holding base is provided in the chamber 3 or a holding frame for holding the pellicle holding jig 2 is provided. The chamber 3 is preferably made of metal or quartz from the viewpoint of not emitting gas from the chamber itself and not promoting the deterioration strength.

  The chamber 3 is provided with an intake port 3a and an exhaust port 3b. It is desirable to provide the intake port 3a of the chamber 3 so as to be positioned below the exhaust port 3b.

  A gas introduction system 5 is connected to the inlet 3 a side of the chamber 3. The gas introduction system 5 includes a gas feed pipe 51 connected to the intake port 3 a, a gas introduction unit 52 that is installed in the gas feed pipe 51 and introduces atmospheric gas, and foreign substances in the atmospheric gas received from the gas introduction unit 52. And a filter 53 that removes chemical contaminants and supplies them into the chamber 3.

  A gas exhaust system 6 is connected to the exhaust port 3 b of the chamber 3. The gas exhaust system 6 includes a gas exhaust pipe 61 connected to the exhaust port 3 b and a gas exhaust unit 62 that is installed in the gas exhaust pipe 61 and exhausts atmospheric gas from the chamber 3.

  The controller 7 monitors and controls the flow rate, atmospheric pressure, and temperature of the atmospheric gas introduced into the chamber 3. The controller 7 controls the gas introduction unit 52 and the gas exhaust unit 62, introduces a desired atmospheric gas flow rate into the chamber 3, and controls the inside of the chamber 3 to have a desired gas pressure. Further, the controller 7 has a role of variably controlling the gas temperature in the chamber 3 and thus the temperature of the pellicle 1 via the heating device 4.

FIG. 2 is a diagram illustrating a configuration example of the pellicle 1.
The pellicle 1 is obtained by attaching a membrane (pellicle film) 1b with an adhesive 1c to two frames 1a and 1a arranged at a predetermined interval. The pellicle 1 is affixed to a photomask with an adhesive 1d applied to the surface of the pellicle frame 1a, 1a opposite to the membrane 1b.

FIG. 3 is a view showing a configuration example of the pellicle holding jig 2 and is housed in the chamber 3.
The pellicle holding jig 2 includes a plurality of shelves 2b,... For holding the pellicle 1 in a frame structure frame 2a having a box-shaped outer shape extending in the vertical direction, and each shelf 2b,. A vent window 2d is opened in the bottom plate 2c which plays a role.

  The pellicle holding jig 2 may be one in which a wall plate material is attached to a necessary outer surface portion of the frame structure frame 2a, and a ventilation window 2d is opened in these wall plate materials.

  Further, when the ventilation window 2d is formed on the bottom plate 2c that plays the role of a shelf, for example, leg portions having a predetermined height are attached to the four corners of the bottom of the pellicle holding jig 2, and the ventilation window 2d formed on the bottom plate 2c is used. The structure should allow sufficient ventilation.

  The pellicle holding jig 2 is preferably made of metal or quartz from the viewpoint of preventing gas from being emitted from the holding jig itself and not promoting the deterioration strength of the pellicle holding jig 2 itself.

Further, returning to FIG. 1, the components of the degassing device for the pellicle will be described in detail.
The internal space 3c of the chamber 3 needs to be filled with an atmospheric gas having a desired flow rate, atmospheric pressure, and temperature. The atmospheric gas is an inert gas such as N2 or a rare gas, an active gas such as O2 or H2O, air, or a mixed gas thereof. Note that the type and mixing ratio of the mixed gas, the flow rate, the pressure, and the temperature can be appropriately selected as necessary depending on the constituent members of the target pellicle 1.

  Although not shown, the controller 7 receives measurement values from a flow meter, a pressure gauge, etc. installed at an appropriate position of the gas introduction pipe 51 on the gas introduction unit 52 output side. Based on the above, the gas introduction unit 52 is controlled so that the atmospheric gas introduced into the chamber 3 is adjusted to the set flow rate and the set pressure. The atmospheric gas having the set flow rate and set pressure is introduced into the chamber 3 through the filter 53 and the intake port 3a. The controller 7 can control the gas exhaust unit 62 to exhaust the atmospheric gas having a predetermined flow rate and pressure from the internal space 3 c in the chamber 3 to the outside of the chamber 3 via the gas exhaust pipe 61.

  Further, the controller 7 controls the heating device 4 based on a measured value of a thermometer (not shown) installed in the heating device 4 or the chamber 3 and a preset temperature, and the internal space 3 c in the chamber 3 is controlled. The atmospheric gas can be heated to a set temperature.

  The control of the atmospheric gas temperature in the chamber 3 may be adjusted based on a control command from the controller 7 so that the heating device 4 itself takes in the atmospheric gas temperature in the internal space 3c of the chamber 3 and becomes the set temperature. . As a heat source of the heating device 4, a heating wire heater is used, but a heat source such as a lamp heater may be used.

Next, a method for degassing the pellicle 1 will be described.
The pellicle 1 is mounted on the shelf 2 b of the pellicle holding jig 2 and held in the chamber 3. At this time, the gas introduction system 5 and the gas exhaust system 6 are connected to the chamber 3 and are in a state of receiving a control instruction from the controller 7.

  The controller 7 controls the gas introduction unit 52 and the gas exhaust unit 62 to control the gas flow rate and the gas pressure of the atmospheric gas introduced into the gas feed pipe 51 so as to become the set values. Introduce. Further, the controller 7 or the heating device 4 controls the atmospheric gas in the internal space 3 c of the chamber 3 to a set temperature.

  Then, by executing the control operation as described above, the internal space 3c of the chamber 3 is sufficiently replaced with the atmospheric gas, and when the internal space 3c of the chamber 3 is heated by the heating device 4, the pellicle 1 is Heated.

  Here, when the pellicle 1 is heated, the outgas of the pellicle member and the gas adsorbed from the environment during storage of the pellicle member are degassed. The degassing is exhausted out of the chamber 3 via the exhaust port 3 b and the gas exhaust pipe 61 according to the control of the gas exhaust unit 62.

  When degassing is performed, the atmospheric gas in the internal space 3c of the chamber 3 may be always introduced and evacuated. For example, after introducing the atmospheric gas into the chamber 3, After the pellicle 1 is sufficiently heated, the atmospheric gas in the chamber 3 may be exhausted.

  In addition, as the degassing process, there are a case where a series of processes of introduction, heating, and exhaust of atmospheric gas are performed once within a predetermined processing time and a plurality of times within the processing time. It is preferable to perform the process a plurality of times because the atmospheric gas in contact with the pellicle 1 is not contaminated by the degassing of the pellicle 1.

Examples of the present invention will be described below.
The pellicle 1 left in the photomask process is set on the pellicle holding jig 2 and accommodated in the chamber 3. At this time, if the gas introduction system 5 and the gas exhaust system 6 are not connected to the chamber 3, the gas introduction system 5 and the gas exhaust system 6 are connected to the chamber 3 to complete the preparation.

  The controller 7 controls the gas introduction unit 52, for example, takes in room temperature and a flow rate of 1 L / min due to room air and introduces them into the filter 53, and introduces air in a state free of foreign substances and chemical contaminants into the chamber 3. Then, the air is made to flow, and the heating device 4 is heated for 5 hours so that the internal space 3c of the chamber 3 becomes 40 ° C.

  After that, the pellicle 1 was taken out from the pellicle holding jig 2, heated at 80 ° C. for 30 minutes with an analysis sampler, the generated gas was adsorbed on an adsorption tube, and analyzed by a heat desorption type GC / MS method. The total of volatile organic substances was 2.9 ug.

  As in the first embodiment, the pellicle 1 left in the photomask process is set on the pellicle holding jig 2 and accommodated in the chamber 3, and then the gas introduction system 5 and the gas exhaust system 6 are connected to the chamber 3. .

  The controller 7 controls the gas introduction unit 52, for example, takes room temperature and flow rate of 1 L / min by room air, introduces it into the filter 53, introduces air without foreign matter or chemical contaminants into the chamber 3, and flows the air for a while. After that, the inlet 3a and the outlet 3b of the chamber 3 are closed, and the chamber 3 is sealed.

  In the above state, after heating for 10 minutes so that the internal space 3c of the chamber 3 becomes 40 ° C. with the heating device 4, the intake port 3a and the exhaust port 3b of the chamber 3 are opened and air is allowed to flow for a while. Then, the chamber 3 is closed again. And it heated again for 10 minutes with the heating apparatus 4 so that the internal space 3c of the chamber 3 might be 40 degreeC. Thereafter, this series of operations was repeated, and the total was repeated 28 times.

  Thereafter, the pellicle 1 was taken out from the pellicle holding jig 2, heated at 80 ° C. for 30 minutes with an analysis sampler, the generated gas was adsorbed on an adsorption tube, and analyzed by a heat desorption type GC / MS method. The total of volatile organic substances was 1.8 ug.

Comparative Example 1

  As in Examples 1 and 2, the pellicle 1 left in the photomask process was heated with an analysis sampler at 80 ° C. for 30 minutes, and the generated gas was adsorbed on an adsorption tube, and the heat-desorption GC / MS method was used. Upon analysis, the total amount of volatile organic substances was 6.3 ug.

Therefore, when the above examples and comparative examples are summarized, the amount of volatile organic substances generated per pellicle as shown in FIG. 4 was obtained.

Therefore, according to the embodiments and examples as described above, the pellicle 1 is held in the chamber 3, and the ambient gas is supplied from the gas introduction system 5 under the control instruction from the controller 7. After the pressure is adjusted and introduced into the chamber 3, the heating device 4 heats the inside of the chamber 3 under the control command of the controller 7, so outgas generated from the pellicle member of the pellicle 1 In addition, the adsorbed gas to be adsorbed can be surely degassed. In addition, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the scope of the invention.

  DESCRIPTION OF SYMBOLS 1 ... Pellicle, 1a ... Pellicle frame (pellicle film), 1c, 1d ... Adhesive, 2 ... Pellicle holding jig, 2a ... Frame structure frame, 2b ... Shelf, 2d ... Ventilation window, 3 ... Chamber, 3a ... Intake port 3b ... exhaust port, 3c ... chamber internal space, 4 ... heating device, 5 ... gas introduction system, 6 ... gas exhaust system, 7 ... controller, 51 ... gas feed pipe, 52 ... gas introduction unit, 53 ... filter, 61 ... Gas exhaust pipe, 62 ... Gas exhaust unit.

Claims (14)

  A chamber for holding the pellicle inside, a gas introduction system for introducing atmospheric gas into the chamber, and controlling the gas introduction system to adjust the atmospheric gas to a required gas flow rate and a required gas pressure. A degassing device for a pellicle, comprising a controller to be introduced into the chamber. The pellicle degassing apparatus according to claim 1,
A pellicle degassing apparatus having a heat source for heating the chamber, and provided with heating means for controlling the temperature of the pellicle in the chamber and the atmospheric gas according to the control command of the controller or itself . The degassing apparatus for a pellicle according to claim 1 or 2,
A pellicle degassing apparatus, wherein a pellicle holding jig for holding the pellicle is accommodated in the chamber. The pellicle degassing apparatus according to claim 3,
2. The pellicle degassing apparatus according to claim 1, wherein the pellicle holding jig has a plurality of shelves on which the pellicle is placed, and a ventilation window is formed in each of the shelves. The degassing apparatus for a pellicle according to claim 1 or 2,
The gas introduction system includes a gas feed pipe for sending the atmospheric gas into the chamber and a gas feed pipe installed in the gas feed pipe and flowing through the gas feed pipe under the control command of the controller. A gas introduction unit for controlling the flow rate and gas pressure,
A degassing apparatus for a pellicle, wherein an atmospheric gas having a stable gas flow rate and gas pressure is supplied to the chamber from the gas introduction unit. The degassing apparatus for a pellicle according to claim 1 or 2,
A gas exhaust system for exhausting atmospheric gas in the chamber is connected to the chamber,
The gas exhaust system includes a gas exhaust pipe for exhausting the atmospheric gas in the chamber to the outside, a gas flow rate of the atmospheric gas installed in the gas exhaust pipe and exhausted under a control command of the controller, and A gas exhaust unit for controlling the gas pressure,
A degassing device for a pellicle, wherein atmospheric gas having a stable gas flow rate and gas pressure is exhausted from the gas exhaust unit to the outside. In the degassing apparatus of the pellicle according to any one of claims 1, 2, and 5,
A degassing apparatus for a pellicle, provided with a filter that is installed in the gas feed pipe on the downstream side of the gas introduction unit and removes foreign substances and chemical contaminants existing in the atmospheric gas. A holding step for holding the pellicle in the chamber; a gas supplying step for supplying atmospheric gas into the chamber holding the pellicle; and replacing the atmospheric gas supplied in the gas supplying step in the chamber, and then the chamber A pellicle in the inside and a heating step for controlling the atmospheric gas so as to have a predetermined temperature,
A method for degassing a pellicle, comprising degassing outgas from the pellicle and gas adsorbed from the environment during storage. The method for degassing a pellicle according to claim 8,
In the gas supply step, the foreign matter and chemical contaminants present in the atmospheric gas are removed and supplied to the pellicle holding chamber, and the pellicle degassing method. The method for degassing a pellicle according to claim 8 or 9,
The method for degassing a pellicle, wherein the atmospheric gas is an inert gas such as N2 or a rare gas, an active gas such as O2 or H2O, or air. The method for degassing a pellicle according to any one of claims 8 to 10,
A method for degassing a pellicle, characterized in that the atmospheric gas supplied into the chamber holding the pellicle is controlled to have a required gas flow rate and gas pressure. The method for degassing a pellicle according to any one of claims 8 to 10,
A method for degassing a pellicle, wherein the atmospheric gas in the chamber is exhausted outside at a required flow rate and pressure.   The supply of the atmospheric gas according to claim 11 and the external exhaust of the atmospheric gas according to claim 12 are repeated, and the inside of the chamber is replaced with a required atmosphere at an arbitrary timing. Pellicle degassing method. The method for degassing a pellicle according to claim 8,
The chamber accommodates a pellicle holding jig on which the pellicle is placed in each shelf provided with a ventilation window, and the space between the pellicle and the shelf is set in a state in which ventilation is possible. Pellicle degassing method.

Images