JP2002293685A - Crystal manufacturing method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal manufacturing method and apparatus for manufacturing a single crystal having excellent optical characteristics with good reproducibility by more exactly controlling the face orientation grown by crystalline substance. SOLUTION: The crystal manufacturing method for growing the single crystal through a seed crystal from the raw material of the crystalline substance housed into a crucible has a step of setting the diameter of the seed crystal at a prescribed ratio to the diameter of the optical element manufactured from the seed single crystal to be grown and housing this seed crystal into the crucible and a step of detecting the temperature of the melting position of the seed crystal and the temperature of the melt respectively by detectors 132a and 132b and controlling a heater 136 or in turn the height of the crucible 100 across a controller 134, thereby melting a portion of the seed crystal and maintaining the unmelted part of the seed crystal at a prescribed length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to the production of crystalline materials, and more particularly to a method and apparatus for growing a single crystal from a raw material containing a crystalline material and a seed crystal in a crucible. INDUSTRIAL APPLICABILITY The present invention is suitable, for example, for producing fluorite suitable for various optical elements, lenses, window materials, prisms, and the like used in a wide wavelength range from the vacuum ultraviolet region to the far infrared region.

[0002]

2. Description of the Related Art In recent years, the demand for miniaturization and thinning of electronic equipment has increased the demand for miniaturization of semiconductor elements mounted on electronic equipment, and proposals have been made to increase the exposure resolution in order to satisfy such demands. There are various. Since shortening the wavelength of the exposure light source is an effective means for improving the resolution, in recent years, the exposure light source has been changed from a Kr-F excimer laser (wavelength: about 248 nm) to an Ar-F excimer laser (wavelength: about 193 nm). The practical use of F ₂ excimer laser (wavelength: about 157 nm) is also progressing. Since calcium fluoride single crystal (CaF ₂ ) has high transmittance (that is, internal transmittance) of light in such a wavelength range, it is most suitable as an optical material of an optical element such as a lens or a diffraction grating used in an exposure optical system. It is.

[0003] Single crystals of calcium fluoride have conventionally been
Manufactured by the crucible descent method (also known as the "Bridgeman method"). Such a method is a method in which a raw material of a crystalline substance is filled in a crucible, and the raw material melted by heating with a heater is crystallized by lowering and cooling the crucible. At this time, the plane orientation of the growing crystal was controlled by arranging a seed crystal at the lower part of the crucible as a starting point of the growth having the desired plane orientation. Since calcium fluoride single crystal has excellent optical characteristics (for example, low birefringence) in the crystal plane orientation (1 1 1) plane, the crystal is oriented to the (1 1 1) plane during its production. Using a seed crystal, the crystal is grown while being controlled to such a plane orientation.

[0004]

However, according to the conventional method and apparatus for producing a crystal, the plane orientation of a calcium fluoride single crystal cannot completely match the (11 1) plane, and high quality optical characteristics can be obtained. Could not be produced with good reproducibility.

As a result of the inventor's intensive study of the reason, the plane orientation of the growing calcium fluoride single crystal is controlled as follows.
Depending on the melting state of the seed crystal when the single crystal grows from the raw material, the size of the optical element manufactured from the single crystal, the size of the seed crystal relative to the area, the area, and the area where the seed crystal contacts the raw material I found that. That is, simply melting and cooling the raw material of calcium fluoride is not necessarily (1).
1 1) Does not grow from the surface. In order for the calcium fluoride raw material to grow from the (111) plane, it is necessary that the seed crystal is melted at a site in contact with the raw material (that is, the (111) plane). Depending on the state of the seed crystal at the time of growth (for example, it is not completely melted or completely melted), (11 1)
The plane does not become dominant. Further, if the size of the seed crystal is too small relative to the optical element manufactured from the single crystal, the optical characteristics of the optical element deteriorate. Furthermore, the raw material of calcium fluoride is typically in partial contact with the seed crystal at the bottom of the crucible, and if the growth of the single crystal starts from a portion that is not in contact with the seed crystal, the plane orientation of that portion is (1 1 1) It does not coincide with the plane.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide a new and useful crystal manufacturing method and apparatus which can solve such conventional problems.

More specifically, the present invention provides a method and apparatus for producing a single crystal having excellent optical characteristics with good reproducibility by more accurately controlling the plane orientation on which a crystalline substance grows. For illustrative purposes.

In order to achieve the above object, a crystal manufacturing method according to one aspect of the present invention is a crystal manufacturing method for growing a crystal from a raw material of a crystalline substance contained in a crucible via a seed crystal. By measuring the temperature in the vicinity of the crystal and controlling the temperature in the vicinity of the seed crystal based on the measurement result, a part of the seed crystal is melted and the unmelted portion of the seed crystal is maintained at a predetermined length. It is characterized by the following. In such a method, the seed crystal is partially melted by controlling the temperature near the seed crystal to maintain the length of the unmelted portion of the seed crystal at a predetermined length (for example, 10 mm or more). Thereby, it is possible to prevent the seed crystal from not being able to maintain the plane orientation of the single crystal without being melted or being completely melted. The control includes controlling the heating means for heating the crucible and controlling the position of the crucible. For example, the heating unit is controlled so that the temperature of the melting position of the storage unit for storing the seed crystal is maintained at the melting point, and the temperature of the storage unit at a position from the raw material is higher than the melting point.

According to another aspect of the present invention, there is provided a single crystal manufacturing method for growing a crystal from a raw material of a crystalline substance contained in a crucible via a seed crystal. The diameter of the growth surface of the seed crystal is set to a predetermined ratio with respect to the diameter of the optical element manufactured from the above, and the seed crystal is housed in the crucible. In such a method, by controlling the direct line of the growth surface of the single crystal with respect to the diameter of the optical element to a predetermined ratio (for example, 2% or more), the plane orientation of the single crystal is set with the seed crystal as the starting point of crystal growth. Control stably.

According to another aspect of the present invention, there is provided a method for producing a single crystal, comprising: growing a crystal from a raw material of a crystalline substance contained in a crucible via a seed crystal; The area of the seed crystal on the growth surface of the optical element to be formed is set at a predetermined ratio with respect to the area of the surface substantially perpendicular to the crystal growth direction, and the seed crystal is housed in the crucible. And In such a method, the surface orientation of the single crystal is stabilized by controlling the area of the growth surface of the seed crystal with respect to the area of the optical element to a predetermined ratio (for example, 0.04% or more) by using the seed crystal as a starting point of crystal growth. And control.

According to another aspect of the present invention, there is provided a crucible comprising: a first storage section for storing a raw material of a crystalline substance; and a second substantially cylindrical storage for storing a seed crystal for growing a single crystal from the raw material. Part, and the raw material stored in the first storage part is disposed between the first and second storage parts, and is connected to the seed crystal in a region equal to or smaller than the diameter of the second storage part. And an introduction part that enables The introduction portion has the same shape or a different shape as the seed crystal. According to such a crucible, the introduction section limits the starting point of the growth of the raw material to the seed crystal plane.

According to still another aspect of the present invention, there is provided a method for producing a crystal, wherein the single crystal is grown using the above-mentioned crucible.
According to such a crystal manufacturing method, since the crystal can be grown only from the seed crystal, the plane orientation of the crystal to be grown can be matched with the plane orientation of the seed crystal. The crystalline substance is made of, for example, calcium fluoride. However, the present invention does not exclude other materials such as potassium fluoride and magnesium fluoride.

According to another aspect of the present invention, there is provided a crystal manufacturing apparatus comprising: a crucible having a seed crystal storage section for storing a raw material of a crystalline substance and storing a seed crystal for growing a crystal from the raw material; Through the crucible, a heating device that heats the raw material and the seed crystal, a temperature measuring device that measures the temperature of the seed crystal storage unit, and a temperature around the seed crystal based on the measurement result of the temperature measuring device. And a control device for controlling. Such an apparatus has the same operation as any of the above-described methods.

According to still another aspect of the present invention, there is provided a crystal manufacturing apparatus, wherein the seed crystal is so formed as to maintain the seed crystal at a predetermined ratio with respect to the diameter of the single crystal to be grown in the growth direction. The above-mentioned crucible stored in the storage section of No. 2,
A heating device disposed around the crucible to heat the crucible; and a heating device for growing the single crystal from the raw material so as to maintain an unmelted portion of the seed crystal at a predetermined length. And a temperature control mechanism for controlling the temperature at the melting position of the seed crystal to the melting point of the seed crystal. Such a crystal manufacturing apparatus maintains both the operation of the above-described crucible and the operation of the above-described crystal manufacturing method.

An optical element according to still another aspect of the present invention is manufactured from the crystal obtained from the above-described crystal manufacturing method, crucible and crystal manufacturing apparatus. Such optical elements are, for example, lenses,
Includes diffraction gratings, optical films and composites thereof, such as lenses, multi-lenses, lens arrays, lenticular lenses, fly-eye lenses, aspheric lenses, diffraction gratings, binary-optics elements and composites thereof.

An exposure apparatus according to still another aspect of the present invention utilizes ultraviolet light, far ultraviolet light, and vacuum ultraviolet light as an exposure body, and receives the exposure light via an optical system including the above-described optical element. The object to be processed is exposed by irradiating the object to be processed. Such an exposure apparatus has the same function as the optical element.

According to still another aspect of the present invention, there is provided a device manufacturing method, wherein the object to be processed is projected and exposed by using the above-described exposure apparatus, and a predetermined process is performed on the object to be projected and exposed. And steps. The claims of the device manufacturing method having the same operation as that of the above-described exposure apparatus extend to the device itself as an intermediate and final product. Such a device is, for example, LS
Includes semiconductor chips such as I and VLSI, CCDs, LCDs, magnetic sensors, thin-film magnetic heads, and the like.

A further object or other feature of the present invention is that
The present invention will be clarified by preferred embodiments described below with reference to the accompanying drawings.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor has described calcium fluoride (C
A large number of calcium fluoride crystals were produced by changing the production conditions during the production of aF ₂ ) crystals, and the optical characteristics (connection rate between seed crystal and raw material, birefringence) were measured.

The apparatus 1 and the method 1000 for producing calcium fluoride crystals of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, and each component may be replaced as long as the object of the present invention is achieved. For example, the method of cooling the molten raw material is not limited to the crucible lowering method mentioned in the conventional technology, a method of fixing the crucible and raising the heater, a method of gradually decreasing the heater output, and any other known method. It may be a method. FIG. 2 shows a flowchart of a method 1000 for producing calcium fluoride of the present invention.

First, a raw material for synthesizing high-purity calcium fluoride is prepared as a raw material. A synthetic raw material of high-purity calcium fluoride is produced by reacting calcium carbonate (CaCO ₃ ) and hydrofluoric acid (HF) as shown in the following chemical formula 1. The present invention does not exclude a method of removing impurities (for example, SiO ₂ ) by treating a raw calcium fluoride with hydrogen fluoride, but high-purity calcium fluoride is a powder unlike the raw stone and has a bulk density. (About 10 to about 20μ
And) very small and preferred.

[0022]

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It is preferable that the calcium fluoride synthesized by the above reaction is dried and then calcined to remove water. The calcium fluoride raw material obtained by the above synthesis is desirably vacuum-packed so as not to be exposed to the atmosphere as much as possible in order to prevent absorption of moisture.

Next, the calcium fluoride raw material and the scavenger are mixed (step 1100). In addition, when mixing a calcium fluoride raw material and a scavenger, it is preferable to put a calcium fluoride raw material and a scavenger in a mixing container, and to rotate and ensure uniform mixing.

As the scavenger, zinc fluoride, cadmium fluoride, manganese fluoride, bismuth fluoride, sodium fluoride, lithium fluoride, etc., which are more easily combined with oxygen than the fluoride to be grown, and are easily decomposed and evaporated. Is desirable. A substance which reacts with the oxide mixed in the fluoride raw material to become an oxide which is easily vaporized is selected. In particular, zinc fluoride is desirable.

For example, as shown in the following chemical formula 2, zinc fluoride (ZnF ₂ ) scavenger is calcium oxide (CaO) generated by the presence of moisture with respect to CaF ₂ .
Is reduced to CaF _{2 as} shown in the following chemical formula 3.

[0027]

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[0028]

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The more water, the more scavenger is required, while the unused scavenger residue becomes an impurity for the calcium fluoride crystals. For this reason, it is preferable to reduce the amounts of moisture and scavenger. The amount of the scavenger added in the present embodiment is:
It is 0.05 mol% or more and 5.00 mol% or less, and more preferably 0.1 to 1.0 mol%. If the amount of addition is large, the homogeneity of the refractive index, the internal transmittance, and the laser durability are reduced due to the residual scavenger.

The mixture of the calcium fluoride powder and the scavenger thus obtained is subjected to a purification treatment (step 1200). The purification process involves impurities (eg,
This is a step of purifying calcium fluoride by removing carbonic acid, and includes actions of dehydration, scavenging reaction, removal of scavenger products, melting and solidification. In the refining process, the mixture is placed in a crucible of a refining furnace.

Thereafter, the heater is energized to heat the mixture in the crucible to perform dehydration.

As described above, dehydration is also performed during the purification process in step 1200. At the temperature at which the reaction has been completed, the purification furnace is evacuated to a vacuum by an evacuation system, and then the calcium fluoride raw material is completely melted. Subsequently, the crucible is lowered, and the molten calcium fluoride raw material is gradually cooled to grow crystals.

The purpose of this step is to increase the bulk density, and does not require temperature control as in the single crystal growth step (step 1300) described later. Therefore, the resulting crystal may be polycrystalline or may have grain boundaries. Good. The upper part of the crystal thus obtained, that is, the part that has crystallized last with time is removed. Since this portion is a portion where impurities are likely to collect (ie, segregate), removing this portion removes impurities that adversely affect the characteristics. Again, this crystal is put into a crucible, and a series of steps of melting, crystallization, and removal of the upper portion are repeated a plurality of times.

Next, a single crystal growth process is performed on the purified calcium fluoride crystal (step 130).
0). The single crystal growth step is a step of growing a single crystal of calcium fluoride to improve the quality of the crystal (that is, to arrange a lattice arrangement). In this step, (Step 1 described later)
A seed crystal whose diameter is set to a predetermined ratio with respect to the diameter of the optical element manufactured from the grown single crystal (described by 500) is set in a storage portion below the crucible, and a part of the seed crystal is melted. At the same time, a single crystal is grown while maintaining the unmelted portion of the seed crystal at a predetermined length. An appropriate growth method is selected according to the size of the crystal and the purpose of use. The purified crystal is placed in a crucible housed in a chamber of a crystal growth furnace 1 described later with reference to FIG.

After that, the heater is energized and the calcium fluoride raw material (crystal) in the crucible is heated to about 1390-1450 ° C.
Heat to a degree to completely melt the calcium fluoride crystals. Thereafter, the crucible is gradually lowered at a rate of 0.1 to 5.0 mm / h (pass through a predetermined temperature gradient), and the melted calcium fluoride crystal is gradually cooled to form a single crystal based on the seed crystal. Grow.

Subsequently, the fluoride single crystal that has grown is heat-treated in an annealing furnace (annealing step) (step 14).
00). The annealing step is a step of subjecting the grown calcium fluoride single crystal to a heat treatment to remove distortion causing crystal breakage. The grown single crystal is placed in a crucible housed in a chamber of an annealing furnace.

In the annealing step, the crucible is uniformly heated to about 900 ° C. to about 1000 ° C. to remove the distortion of the calcium fluoride crystal in a solid state. Heating temperature about 1140 ° C
This is not preferable because it causes a structural change or the like. The heating time is about 20 hours or more, more preferably about 20 to about 30 hours. In the annealing step, dislocations of the crystal are reduced by annealing. Thereafter, the temperature of the calcium fluoride crystal is returned to room temperature while maintaining the state in which the distortion has disappeared. The fluoride single crystal thus obtained has an oxygen content of 25 ppm or less, water, iron (Fe),
Undesirable impurities such as nickel (Ni) and chromium (Cr) can each be reduced to 10 ppm or less. The refractive index homogeneity (homogeneity) measurement and the birefringence (strain) measurement of the fluoride single crystal obtained by the above steps were performed. Refractive index homogeneity is determined from transmitted wavefront and surface accuracy measurements by an interferometer, and birefringence is measured by a high-precision strainmeter.

Thereafter, the calcium fluoride crystal is formed into a required optical element (step 1500). Optical elements include lenses, diffraction gratings, optical films and composites thereof, such as lenses, multi-lenses, lens arrays, lenticular lenses, fly-eye lenses, aspheric lenses,
Includes diffraction gratings, binary optics elements and composites thereof. The optical element includes an optical sensor (for example, for focus control) in addition to a single lens or the like. If necessary, an antireflection film may be provided on the surface of the fluoride crystal optical article. As the antireflection film, magnesium fluoride, aluminum oxide, or tantalum oxide is preferably used, and these can be formed by vapor deposition by resistance heating, electron beam vapor deposition, sputtering, or the like. Since the optical element obtained by the present invention has few crystal defects, the adhesion of the antireflection film is excellent. In polishing for forming required optical article shapes (convex lens, concave lens, disk shape, plate shape, etc.), partial surface accuracy is reduced due to low dislocation density in calcium fluoride crystal. Is extremely small, and high-precision machining is possible with an allowable value or less.

By combining the lenses thus obtained in various ways, a projection optical system and an illumination optical system suitable for an excimer laser, particularly an ArF excimer laser and an F ₂ excimer laser can be constructed. And an excimer laser light source,
An exposure system for photolithography can be configured by combining an optical system having a lens made of a calcium fluoride crystal obtained by the production method of the present invention and a stage capable of moving a substrate.

FIG. 1 is a schematic sectional view of a crystal manufacturing apparatus (here, a crystal growth furnace) 1 used in step 1300 described above. The crystal manufacturing apparatus 1 melts the raw material in the crucible 100 and then cools the raw material to grow the crystal. In the apparatus 1, the substantially cylindrical crucible 100 supported so as to be able to move up and down by the crucible elevating unit 120 is housed in a furnace chamber 160 defined by a substantially cylindrical housing 150 and a heat insulating member 140, and a temperature control mechanism 130 is provided. Crucible 1
00 is heated from around the cylindrical surface. In addition, the device 1
An exhaust unit (not shown) for maintaining the furnace chamber 160 in a reduced pressure or vacuum environment is provided.

The crucible 100 is made of a crystalline material (in this embodiment,
A raw material 180 (calcium fluoride) is stored. Calcium fluoride (thermal conductivity at 1500 ° C. 3 W / m ° C.) is used as the crystalline substance 180, and the crucible 100 is made of carbon (150 ° C.).
If the thermal conductivity at 0 ° C. is 50 W / m ° C.), the difference in the thermal conductivity is 10 times or more.

The seed crystal 104 of the crucible 100 is stored in a storage section 100a provided in the lower part 102. The seed crystal 104 (that is, a crystal used as a seed when growing a large single crystal having a certain crystal orientation) is oriented in an arbitrary direction (in this embodiment, the (11 1) plane is oriented to the raw material side). T) By arranging the crystal in the storage section 100a, the crystal plane orientation to be grown can be controlled. That is, the plane orientation of the entire crystal to be grown is determined mainly by where the portion of the growth region is dominant in terms of heat capacity, so that the plane orientation can be aligned with the seed crystal 104.

The crucible 100 is connected to the crucible support bar 110 at the lower part 102 and is installed at the center of the furnace chamber 160. The crucible 100 is made of a material that does not react with the melt and has a low impurity content, for example, carbon, platinum, quartz glass, boron nitride, and the like, in order to dissolve, hold, and grow crystals of the raw material 180 of the crystalline substance. Preferably. In the present embodiment, graphite or platinum is used as the material of the crucible 100.

The crucible support rod 110 penetrates the bottom of the casing 150 and reaches the furnace chamber 160 at the top. Crucible support rod 110
Supports the crucible 100 and the weight of the melt in the crucible 100 and is driven by the crucible elevating unit 120 to move the crucible 100 up and down. The crucible elevating unit 120 includes a motor 122 connected to the crucible support rod 110 and a power supply 12 for energizing the motor 122.
4 and a control device 126 for controlling the power supply 124. The control device 126 controls the energization of the motor 122 by the power supply 124 so that the crucible 100
The temperature of the crucible 100 can be gradually lowered by moving from the heating region 36 to the non-heating region. When performing crystal growth, the crucible 100 is lowered at a speed of about 0.1 mm to 5 mm per hour.

The temperature control mechanism 130 includes the temperature detector 13
2, composed of a control device 134, a heater 136, and a power supply 138; a raw material 180 in the crucible 100;
The temperature of the seed crystal 104 and the temperature of the furnace chamber 160 stored in the furnace are controlled.

The temperature detector 132 is connected to a storage unit 10 described later.
0a, a detector 132a for detecting the temperature of the melting position of the seed crystal 104, and (the raw material 180 and the seed crystal 14).
It is a thermometer such as a thermocouple having a detector 132b for detecting the temperature of the melt 180a (0 is melted and mixed). Strictly speaking, the detector 132a detects the melting position 1 of the seed crystal 104.
The temperature of the melting position 104b is measured through the outer surface of the housing portion 100a. The detector 132b is installed on the upper outer surface of the storage unit 100a, and measures the temperature of the melt 180a via the outer surface. It is assumed that control device 134 knows in advance the relationship between the temperature inside storage portion 100a and the temperature on the outer surface, such as the temperature on the outer surface being about 10 ° C. higher. Each measured temperature is output to the controller 134.

The controller 134 controls the heater 136 via the power supply 138 based on the temperature data received from the temperature detector 132. Specifically, the heater 136 is controlled so that the temperature at the melting position 104b is set to the melting point temperature of the raw material 180 and the temperature of the melt 180a is set to a temperature higher than the melting point.
Alternatively, the control device 134 controls the crucible elevating unit 120 to control the height of the crucible 100, or controls a cooling unit (not shown) that cools only the bottom of the storage unit 100a to control the melting position 104b. The temperature may be controlled.

The heater 136 is energized by a power supply 138, and energization of the heater 136 by the power supply 138 is controlled by a controller 138. The heater 136 is arranged in a ring shape facing the crucible 100, heats the raw material 180 together with the crucible 100, and melts the raw material 180. The heater 136 of this embodiment heats the crucible 100 with a uniform heating force along the vertical direction of the crucible 100. In this embodiment, each heater component is made of carbon or molybdenum.

The temperature of the raw material 180 in the crucible 100 and the temperature in the furnace chamber 160 are controlled by the temperature control mechanism 13 described above.
0, any control means known in the art can be applied, and the details are omitted here.

The heat insulating member 140 is disposed close to the inner surface of the furnace chamber 160 so as to surround the heater 136.
The heat insulating member 140 is made of graphite whose inner surface is well polished, and protects the inner surface of the housing 150 from the heat of the heater 136. The housing 150 is used for the furnace chamber 160 during crystal growth.
The inside atmosphere is shielded from the outside air, and a reduced pressure or vacuum environment in the furnace chamber 160 is maintained.

[0051]

【Example】

Embodiment 1 First, high-purity calcium fluoride as a raw material 180 is produced. After reacting calcium carbonate and hydrofluoric acid to form powdered calcium fluoride, zinc fluoride as a scavenger is added at 0.7% by weight to calcium fluoride, and mixed until both are uniform. .

Next, this mixture was placed in a crucible of a refining furnace, heated to 1360 ° C., and then cooled to obtain a high-purity calcium fluoride as a raw material 180.

Next, the raw material 180 was put in the crucible 100 of the single crystal growth furnace shown in FIG. As a scavenger, zinc fluoride was added to crucible 100 in an amount of 0.1% by weight of calcium fluoride as raw material 180.

The seed crystal 104 stored in the storage part 100a of the crucible 100 has a length of 50 mm with the (11 1) plane facing the inside of the crucible 100 (raw material 180), and the shape of the seed crystal 104 is cylindrical. Shape. The seed crystal 104 has the diameter of the optical element manufactured from the grown single crystal and the seed crystal 1.
The ratio of the diameter (the diameter of the seed crystal / the diameter of the crystal to be grown) on the growth surface of No. 04 is 1%, 1.5%, 2.2%,
Those that were 10% and 30% were used.

FIG. 3 is a schematic diagram of the vicinity of the junction between the seed crystal 104 and the melt 108 a of the raw material 180 and the seed crystal 104.
3A shows a temperature distribution (FIG. 3B) in which the vertical axis represents the height of the unmelted portion 104a of the seed crystal 104 and the horizontal axis represents the temperature. FIG.
Referring to, the growth of a single crystal starts from a melting position 104b which is a junction between the unmelted portion 104a of the seed crystal 104 and the melt portion 180a. That is, the melting position 104b is the raw material 18
The solidification point (melting point) or position G is 0. In this embodiment,
The temperature control near the seed crystal 104 is performed precisely, and the melting position 1
The temperature of 04b was fixed at approximately the melting point (for example, 1400 ° C.). The temperature measurement position is the melting position 104b (seed crystal 104
15 mm from the lower part of the unmelted portion 104a).

The inside of the furnace chamber 160 is provided by an exhaust unit (not shown).
The degree of vacuum was set to 8 × 10 ⁻² Pa. After the temperature of the furnace chamber 160 was raised from room temperature to 1360 ° C. by the heater 136, the degree of vacuum in the furnace chamber 160 was maintained at 2.7 × 10 ⁻⁴ Pa and the temperature at 1360 ° C. for 11 hours.

Next, the crucible 100 was lowered at a speed of 2 mm / h to grow calcium fluoride. The rate of temperature decrease at this time corresponds to about 100 ° C./h.

Next, the grown calcium fluoride and zinc fluoride as a scavenger were put into a crucible of an annealing furnace in an amount of 0.1% by weight based on the calcium fluoride. Evacuate the furnace and raise the temperature of the crucible from room temperature to 900 ° C.
After the temperature was raised at a rate of ° C / h, the crucible was kept at 900 ° C for 20 hours. Thereafter, the temperature was lowered at 6 ° C./h and cooled to room temperature.
This operation was repeated 20 times.

The seed connection ratio (%) of the calcium fluoride crystal produced in the first embodiment (number of calcium fluoride crystals having an upper surface of (11 1) plane / number of trials) and birefringence ( (Strain) (nm / cm) was measured. The average of the measurement results is shown in Table 1 below.

[0060]

[Table 1]

From the above results, it is clear that the use of the optical element manufactured from the grown single crystal in which the ratio of the diameter of the seed crystal to the diameter of the seed crystal is 2% or more provides high reproducibility and high quality fluoridation with little distortion. It can be seen that a calcium single crystal is obtained.

Although the ratio of the diameter of the optical element manufactured from the grown single crystal to the diameter of the growth surface of the cylindrical seed crystal has been described above, it is substantially perpendicular to the direction in which the crystal of the optical element has grown. The ratio between the area on the plane and the area on the growth plane of the seed crystal may be defined, and the same effect as in the case of defining the diameter can be obtained. If the seed crystal is not cylindrical, for example, if it is shaped like a rectangular parallelepiped, it is better to determine the ratio by area. In this case, if the ratio of the area of the seed crystal on the growth surface to the area on the surface substantially perpendicular to the crystal growth direction of the optical element is 0.04% or more, the reproducibility is improved and the distortion is improved. And a high-quality calcium fluoride single crystal having a small number of particles can be obtained.

[0063]

Embodiment 2 First, high-purity calcium fluoride as a raw material 180 is produced. In this embodiment, since the raw material 180 is generated in the same process as in the first embodiment, the description is omitted.

Next, the raw material 180 was put into the crucible 100 of the single crystal growth furnace shown in FIG. As a scavenger, zinc fluoride was added to crucible 100 in an amount of 0.1% by weight of calcium fluoride as raw material 180.

The seed crystal 104 accommodated in the accommodating portion 100a of the crucible 100 is manufactured from a grown single crystal having a length of 50 mm with the (11 1) plane facing the inside of the crucible 100 (raw material 180). Of the optical element and seed crystal 1
A seed crystal 104 having a diameter ratio of 04 (diameter of seed crystal / diameter of crystal to be grown) of 5% was used.

Referring to FIG. 3, in this embodiment, the temperature control near the seed crystal 104 is performed precisely, and the melting position 104b
Was fixed at 1400 ° C. The melting position 104b, which is the temperature measurement position, was 5 mm below the unmelted portion 104a of the seed crystal 104.

The inside of the furnace chamber 160 is provided by an exhaust unit (not shown).
The degree of vacuum was set to 8 × 10 ⁻² Pa. After the temperature of the furnace chamber 160 was raised from room temperature to 1360 ° C. by the heater 136, the degree of vacuum in the furnace chamber 160 was maintained at 2.7 × 10 ⁻⁴ Pa and the temperature at 1360 ° C. for 11 hours.

Next, the crucible 100 was lowered at a speed of 2 mm / h to grow calcium fluoride. The rate of temperature decrease at this time corresponds to about 100 ° C./h.

Next, the grown calcium fluoride and zinc fluoride as a scavenger were put into the crucible of the annealing furnace in an amount of 0.1% by weight based on the calcium fluoride. Evacuate the furnace and raise the temperature of the crucible from room temperature to 900 ° C.
After the temperature was raised at a rate of ° C / h, the crucible was kept at 900 ° C for 20 hours. Thereafter, the temperature was lowered at 6 ° C./h and cooled to room temperature.
This operation was repeated 20 times.

[0070]

Embodiment 3 First, high-purity calcium fluoride as a raw material 180 is produced. In this embodiment, since the raw material 180 is generated in the same process as in the first embodiment, the description is omitted.

Next, the raw material 180 was put into the crucible 100 of the single crystal growth furnace shown in FIG. As a scavenger, zinc fluoride was added to crucible 100 in an amount of 0.1% by weight of calcium fluoride as raw material 180.

The seed crystal 104 accommodated in the accommodating portion 100a of the crucible 100 is manufactured from a single crystal grown to have a length of 100 mm with the (111) plane facing the inside of the crucible 100 (raw material 180). The seed crystal 104 having a ratio of the diameter of the optical element to be formed and the diameter of the seed crystal 104 (diameter of the seed crystal / diameter of the crystal to be grown) of 5% was used.

Referring to FIG. 3, in this embodiment, the temperature control near the seed crystal 104 is precisely performed, and the melting position 104b
Was fixed at 1400 ° C. The melting position 104b, which is the temperature measurement position, was 20 mm below the unmelted portion 104a of the seed crystal 104.

The inside of the furnace chamber 160 is provided by an exhaust unit (not shown).
The degree of vacuum was set to 8 × 10 ⁻² Pa. Then after raising the furnace chamber 160 temperature to 1360 ° C. from room temperature by the heater 136 and held for 11 hours the degree of vacuum in the furnace chamber 160 2.7 × 10 ^-4 Pa, the temperature of 1360 ° C..

Next, the crucible 100 was lowered at a speed of 2 mm / h to grow calcium fluoride. The rate of temperature decrease at this time corresponds to about 100 ° C./h.

Next, the grown calcium fluoride and zinc fluoride as a scavenger were put into the crucible of the annealing furnace in an amount of 0.1% by weight based on the calcium fluoride. Evacuate the furnace and raise the temperature of the crucible from room temperature to 900 ° C.
After the temperature was raised at a rate of ° C / h, the crucible was kept at 900 ° C for 20 hours. Thereafter, the temperature was lowered at 6 ° C./h and cooled to room temperature.
This operation was repeated 20 times.

[0077]

Embodiment 4 First, high-purity calcium fluoride as a raw material 180 is produced. In this embodiment, since the raw material 180 is generated in the same process as in the first embodiment, the description is omitted.

Next, the raw material 180 was put into the crucible 100 of the single crystal growth furnace shown in FIG. As a scavenger, zinc fluoride was added to crucible 100 in an amount of 0.1% by weight of calcium fluoride as raw material 180.

This embodiment uses a crucible 100 having the same shape as that of the first embodiment, except for the structure of the lower portion 102 of the crucible 100. Referring to FIG. 4, the crucible 100 includes a seed crystal 104.
Is stored in the storage section 100a of the lower part 101. Storage unit 10
0a has an introduction portion 100 having the same shape as the seed crystal 104;
b is formed so as to be continuous with the inner surface of the crucible 100, and the diameter of the introduction portion 100b is smaller than the diameter of the storage portion 100a. As a result, dislocations of the crystal (a kind of lattice defect, a series of displacements of atoms along a line (dislocation line) in the crystal) and the like can be significantly reduced. Therefore, when the crystal plane orientation (11 1) plane is used as the growth starting point, the dislocation of the crystal can be reduced by making the diameter of the introduction part 100b smaller than the diameter of the storage part 100a. Thus, a calcium fluoride single crystal having excellent optical characteristics can be manufactured with high yield.

The seed crystal 104 accommodated in the accommodating portion 100a of the crucible 100 has a length of 300 mm with the (111) plane facing the inside of the crucible 100 (raw material 180), and the diameter and seed of the crystal to be grown. Seed crystal 104 having a diameter ratio of crystal 104 (diameter of seed crystal / diameter of crystal to be grown) of 5% was used.

Referring to FIG. 3, in this embodiment, the temperature control near the seed crystal 104 is performed precisely,
Was fixed at 1400 ° C. The temperature was measured at a position 20 mm below the unmelted portion 104a of the seed crystal 104.

The inside of the furnace chamber 160 is provided by an exhaust unit (not shown).
The degree of vacuum was set to 8 × 10 ⁻² Pa. Then, after the temperature of the furnace chamber 160 was raised from room temperature to 1360 ° C. by the heater 136, the degree of vacuum in the furnace chamber 160 was maintained at 2.7 × 10 ⁻⁴ Pa and the temperature was 1360 ° C. for 11 hours.

Next, the crucible 100 was lowered at a speed of 2 mm / h to grow calcium fluoride. The rate of temperature decrease at this time corresponds to about 100 ° C./h.

Next, the grown calcium fluoride and zinc fluoride as a scavenger were put in a crucible of an annealing furnace in an amount of 0.1% by weight based on the calcium fluoride. Evacuate the furnace and raise the temperature of the crucible from room temperature to 900 ° C.
After the temperature was raised at a rate of ° C / h, the crucible was kept at 900 ° C for 20 hours. Thereafter, the temperature was lowered at 6 ° C./h and cooled to room temperature.
This operation was repeated 20 times.

[0085]

Embodiment 5 First, high-purity calcium fluoride to be a raw material 180 is produced. In this embodiment, since the raw material 180 is generated in the same process as in the first embodiment, the description is omitted.

Next, the raw material 180 was put in the crucible 100 of the single crystal growth furnace shown in FIG. As a scavenger, zinc fluoride was added to crucible 100 in an amount of 0.1% by weight of calcium fluoride as raw material 180.

This embodiment uses a crucible 100 having the same shape as that of the first embodiment, except for the structure of the lower portion 102 of the crucible 100. Referring to FIG. 5, the crucible 100 includes a seed crystal 104.
Is stored in the storage section 100a of the lower part 101. Storage unit 10
0a has an introduction portion 10 having a shape different from that of the seed crystal 104;
0c is formed so as to be continuous with the inner surface of the crucible 100, and the diameter at each height of the introduction portion 100c is
0a.

The reason why the introduction portion is formed into a shape other than the cylindrical shape, for example, a shape 100c in FIG. 5 will be described below. FIG. 6 is a diagram for explaining the principle of Ostwald ripping, and reference numeral 100c denotes an introduction portion between the crucible 100 and the storage portion 100a. Reference numeral 300 denotes a main growth portion from the seed crystal 104, and reference numerals 300a and 300b denote portions where growth starts in the middle of the introduction portion 100c, that is, growth portions other than the seed crystal 104. Ostwal
The principle of d ripping is that a crystal having a large radius of curvature and a small surface free energy growing from the seed crystal 104 absorbs a crystal having a small surface radius and a large surface free energy growing from other than the seed crystal.
Since the crystal grown from other than the seed crystal proceeds in only one direction, the crystal grown from 300a or 300b stops growing to some extent by the zigzag-shaped introduction portion 100c as shown in FIG. Growth part 300
It is absorbed by. Therefore, the crystal plane orientation (1
11) When the surface is used as the starting point of growth, 300a or 300
Since there is no crystal that continues to grow from the portion b, and the crystal grows from the main growth portion 300 having the (11 1) plane orientation, the yield of calcium fluoride single crystal having excellent optical characteristics over the whole is obtained. Can be manufactured well.

The seed crystal 104 housed in the housing part 100a of the crucible 100 has a length of 300 mm with the (1,1,1) plane facing the inside of the crucible 100 (raw material 180), and is a single crystal grown. A seed crystal 104 having a ratio (diameter of the seed crystal / diameter of the crystal to be grown) of 5% of the diameter of the optical element and the diameter of the seed crystal 104 was used.

Referring to FIG. 3, in this embodiment, the temperature control near the seed crystal 104 is performed precisely, and the melting position 104b
Was fixed at 1400 ° C. The temperature was measured at a position 20 mm below the unmelted portion 104a of the seed crystal 104.

The inside of the furnace chamber 160 is provided by an exhaust unit (not shown).
The degree of vacuum was set to 8 × 10 ⁻² Pa. Then, after the temperature of the furnace chamber 160 was raised from room temperature to 1360 ° C. by the heater 136, the degree of vacuum in the furnace chamber 160 was maintained at 2.7 × 10 ⁻⁴ Pa and the temperature was 1360 ° C. for 11 hours.

Next, the crucible 100 was lowered at a speed of 2 mm / h to grow calcium fluoride. The rate of temperature decrease at this time corresponds to about 100 ° C./h.

Next, the grown calcium fluoride and zinc fluoride as a scavenger were put in a crucible of an annealing furnace in an amount of 0.1% by weight based on the calcium fluoride. Evacuate the furnace and raise the temperature of the crucible from room temperature to 900 ° C.
After the temperature was raised at a rate of ° C / h, the crucible was kept at 900 ° C for 20 hours. Thereafter, the temperature was lowered at 6 ° C./h and cooled to room temperature.
This operation was repeated 20 times.

The seed connection ratio (%) of the calcium fluoride crystals manufactured in the second to fifth embodiments (the upper surface has the plane orientation (11)
1) The number of calcium fluoride crystals that are planes / the number of trials), birefringence (strain) (nm / cm), and seed crystal 10
4 was measured for the unmelted portion 104a. The average of the measurement results is shown in Table 2 below.

[0095]

[Table 2]

From the above, it was found that when the length of the unmelted portion of the seed crystal was 10 mm or more, a high-quality calcium fluoride single crystal with little distortion could be obtained with good reproducibility.

Hereinafter, an exemplary exposure apparatus 700 of the present invention will be described with reference to FIG. Here, FIG. 7 is a schematic sectional view of an exemplary exposure apparatus 700 of the present invention. The exposure apparatus 700 includes, as shown in FIG.
, Mask 720, projection optical system 730, plate 7
40 and a stage 745. Exposure apparatus 700
Is a scanning projection exposure apparatus that exposes a circuit pattern formed on a mask 720 to a plate 740 by a step-and-repeat method or a step-and-scan method.

The illumination device 710 illuminates the mask 720 on which a transfer circuit pattern is formed, and has a light source section 712 and an illumination optical system 714.

The light source section 712 uses, for example, a laser as a light source. The laser is a 193 nm wavelength Ar
F excimer laser, KrF excimer laser with a wavelength of about 248 nm, may be used, such as F ₂ excimer laser with a wavelength of approximately 157 nm, the kind of laser is not limited to an excimer laser, for example, may be used YAG laser However, the number of lasers is not limited. When a laser is used for the light source unit 712, it is preferable to use a light beam shaping optical system for shaping a parallel light beam from a laser light source into a desired beam shape, and an incoherent optical system for making a coherent laser beam incoherent. . The light source that can be used for the light source unit 712 is not limited to a laser, and one or more lamps such as a mercury lamp and a xenon lamp can also be used.

The illumination optical system 714 illuminates the mask 720 and includes a lens, a mirror, a light integrator, a stop, and the like. For example, a condenser lens, a fly-eye lens, an aperture stop, a condenser lens, a slit, and an imaging optical system are arranged in this order. Illumination optical system 7
14 can be used regardless of on-axis light or off-axis light. The light integrator includes a fly-eye lens, an integrator formed by stacking two sets of cylindrical lens array (or lenticular lenses) plates, and the like, but may be replaced with an optical rod or a diffraction element. An optical element manufactured from the potassium fluoride crystal of the present invention can be used for an optical element such as a lens of the illumination optical system 714.

A circuit pattern (or image) to be transferred is formed on the mask 720, and is supported and driven by a mask stage (not shown). The diffracted light emitted from the mask 720 passes through the projection optical system 730 and is projected on the plate 740. The plate 740 is an object to be processed such as a wafer or a liquid crystal substrate, and is coated with a resist. Mask 72
0 and the plate 740 have a conjugate relationship. In the case of a scanning type projection exposure apparatus, the pattern of the mask 720 is scanned by scanning the mask 720 and the plate 740.
Transfer onto 40. In the case of a stepper (step-and-repeat exposure type exposure apparatus), exposure is performed with the mask 720 and the plate 740 kept stationary.

The projection optical system 730 includes an optical system including only a plurality of lens elements, an optical system including a plurality of lens elements and at least one concave mirror (catadioptric optical system), and a plurality of lens elements and at least one concave mirror. An optical system having a diffractive optical element such as a kinoform, an all-mirror optical system, or the like can be used. When chromatic aberration needs to be corrected, a plurality of lens elements made of glass materials having mutually different dispersion values (Abbe values) may be used, or a diffractive optical element may be configured to cause dispersion in a direction opposite to that of the lens element. I do. An optical element manufactured from the calcium fluoride crystal of the present invention can be used for an optical element such as a lens of the projection optical system 730.

The plate 740 is coated with a photoresist. The photoresist application step includes a pretreatment, an adhesion improver application process, a photoresist application process, and a pre-bake process. Pretreatment includes washing, drying and the like. The adhesion improver application treatment is a surface modification (that is, hydrophobicity treatment by applying a surfactant) treatment for improving the adhesion between the photoresist and the base, and the HMDS (Hexam
An organic film such as ethyl-disilazane is coated or steamed. Prebaking is a baking (firing) step, but is softer than that after development, and removes the solvent.

The stage 745 supports the plate 740. The stage 745 may employ any structure known in the art, and thus a detailed description of the structure and operation will be omitted. For example, the stage 745 can move the plate 740 in the X and Y directions using a linear motor. The mask 720 and the plate 740 are synchronously scanned, for example, and the positions of the stage 745 and a mask stage (not shown) are monitored by, for example, a laser interferometer, and both are driven at a constant speed ratio. The stage 745 is provided, for example, on a stage base supported on a floor or the like via a damper, and the mask stage and the projection optical system 730 are, for example, a lens barrel base mounted on a floor or the like base frame. It is provided on a lens barrel base (not shown) supported above via a damper or the like.

In the exposure, the light beam emitted from the light source 712 illuminates the mask 720 with, for example, Koehler illumination by the illumination optical system 714. Light that passes through the mask 720 and reflects the mask pattern is imaged on the plate 740 by the projection optical system 730. The illumination optical system 714 and the projection optical system 730 used by the exposure apparatus 700 transmit the ultraviolet light, the far ultraviolet light, and the vacuum ultraviolet light with high transmittance, including the optical element manufactured from the calcium fluoride crystal according to the present invention. Therefore, devices (semiconductor elements, LCD elements, imaging elements (such as CCDs), thin-film magnetic heads, etc.) can be provided with high throughput and economical efficiency.

Next, an embodiment of a device manufacturing method using the above-described exposure apparatus 700 will be described with reference to FIGS. FIG. 8 is a flowchart for explaining the manufacture of devices (semiconductor chips such as ICs and LSIs, LCDs, CCDs, etc.). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), the circuit of the device is designed. Step 2 (mask fabrication) forms a mask on which the designed circuit pattern is formed. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is referred to as a preprocess, and an actual circuit is formed on the wafer by lithography using the mask and the wafer. Step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer created in step 4, and includes an assembly process (dicing, bonding),
It includes steps such as a packaging step (chip encapsulation). In step 6 (inspection), inspections such as an operation check test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 9 is a detailed flowchart of the wafer process in Step 4. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the surface of the wafer. Step 13
In (electrode formation), electrodes are formed on the wafer by vapor deposition or the like. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the exposure apparatus 1 to expose a circuit pattern on the mask onto the wafer. Step 17 (development) develops the exposed wafer. Step 18 (etching) removes portions other than the developed resist image. Step 19
In (resist removal), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. According to the manufacturing method of this embodiment, it is possible to manufacture a device having higher quality than the conventional device.

According to the present invention, a single crystal having excellent characteristics can be grown with good reproducibility by using a seed crystal in which the diameter (ratio) and the unmelted portion are set in advance with respect to the diameter of the crystal to be grown. it can. In addition, by providing an introduction portion (having the same or different shape as the seed crystal) connecting the raw material in the crucible with the seed crystal storage portion, the main crystal that grows from the seed crystal starting from a source other than the seed crystal can be formed. It is possible to suppress the formation of a polycrystal by absorption and grow as a single crystal having a plane orientation of a seed crystal.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the invention.

[0110]

According to the method and apparatus for producing a crystal of the present invention, the melting state of a seed crystal when a single crystal is grown from a raw material,
Since the plane orientation of the single crystal can be controlled by controlling the size of the seed crystal relative to the size of the optical element manufactured from the single crystal and / or the area where the seed crystal contacts the raw material, excellent optical characteristics Can be produced with good reproducibility.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a crystal manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of a manufacturing process of optical calcium fluoride.

FIG. 3 is a block diagram showing the vicinity of a seed crystal and a diagram showing a temperature distribution near the seed crystal.

FIG. 4 is a schematic sectional view of a lower portion of a crucible according to a fourth embodiment of the present invention.

FIG. 5 is a schematic sectional view of a lower part of a crucible according to a fifth embodiment of the present invention.

FIG. 6 is a diagram for explaining the principle of Ostwald ripping.

FIG. 7 is a schematic sectional view of an exposure apparatus of the present invention.

FIG. 8 is a flowchart illustrating a device manufacturing method having an exposure step according to the present invention.

FIG. 9 is a detailed flowchart of step 4 shown in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crystal manufacturing apparatus 100 Crucible (crystal part) 100a Storage part 100b Introduction part 130 Temperature control mechanism

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 21/027 H01L 21/30 515D F-term (Reference) 4G077 AA02 BE02 CD02 ED01 EG01 EG18 EH06 MB04 MB23 MB33 5F046 CB10 CB12

Claims (20)

[Claims] 1. A crystal manufacturing method for growing a crystal from a raw material of a crystalline substance stored in a crucible via a seed crystal, wherein a temperature near the seed crystal is measured, and a temperature near the seed crystal is measured based on the measurement result. A crystal manufacturing method, wherein a part of the seed crystal is melted by controlling a temperature, and an unmelted portion of the seed crystal is maintained at a predetermined length. 2. The method according to claim 1, wherein the predetermined length is 10 mm or more. 3. A crystal manufacturing method for growing a crystal from a raw material of a crystalline substance contained in a crucible via a seed crystal, wherein the seed is formed with respect to the diameter of an optical element manufactured from the crystal to be grown. A method for producing a crystal, characterized in that the seed crystal is housed in the crucible with the diameter of the crystal growth surface being set at a predetermined ratio. 4. The method according to claim 3, wherein the predetermined ratio is 2% or more. 5. A crystal manufacturing method for growing a crystal from a raw material of a crystalline substance stored in a crucible via a seed crystal, wherein an optical element manufactured from the crystal to be grown is substantially oriented in the direction of crystal growth. A crystal manufacturing method, wherein the seed crystal is accommodated in the crucible with the area on the growth surface of the seed crystal set to a predetermined ratio with respect to the area on a vertical surface. 6. The method according to claim 5, wherein the predetermined ratio is 0.04% or more. 7. A first storage section for storing a raw material of a crystalline substance, a second storage section having a substantially cylindrical shape for storing a seed crystal for growing a crystal from the raw material, and the first and second storage sections. A crucible having an introduction portion disposed between storage portions, the introduction portion allowing the raw material stored in the first storage portion to be connected to the seed crystal in a region equal to or smaller than the diameter of the second storage portion. . 8. The crucible according to claim 7, wherein the introduction portion has the same shape as the seed crystal. 9. The crucible according to claim 7, wherein the introduction portion has a shape other than a cylindrical shape. 10. A crystal manufacturing method for growing the single crystal using the crucible according to claim 7. Description: 11. The method according to claim 1, wherein the crystalline substance is calcium fluoride. 12. An optical element manufactured from the crystal manufactured by the method for manufacturing a crystal according to claim 1. Description: 13. An optical element manufactured from the crystal manufactured using the crucible according to claim 7. Description: 14. A crucible having a seed crystal storage portion for storing a raw material of a crystalline substance and storing a seed crystal for growing a crystal from the raw material, and the raw material and the seed through the crucible. A crystal manufacturing apparatus, comprising: a heating device that heats a crystal; a temperature measuring device that measures the temperature of the seed crystal storage unit; and a control device that controls a temperature around the seed crystal based on a measurement result of the temperature measuring device. 15. The seed crystal is stored in the second storage part such that a diameter of the seed crystal with respect to a diameter of a plane perpendicular to a growth direction of the crystal to be grown is maintained at a predetermined ratio. A crucible according to any one of claims 7 to 9, a heating device disposed around the crucible and heating the crucible, and an unmelted portion of the seed crystal when growing the crystal from the raw material. A temperature control mechanism for controlling a temperature of a melting position of the seed crystal by the heating device to a melting point of the seed crystal in order to maintain a predetermined length. 16. An optical element manufactured from the crystal manufactured by using the crystal manufacturing apparatus according to claim 14. Description: 17. The optical element according to claim 12, which is one of a lens, a diffraction grating, an optical film, and a composite thereof. 18. An object using ultraviolet light, far ultraviolet light and vacuum ultraviolet light as an exposure object, and irradiating the exposure object with the exposure light via an optical system including the optical element according to claim 17. An exposure apparatus that exposes a processed object. 19. A device manufacturing method comprising: a step of projecting and exposing the object using the exposure apparatus according to claim 18; and a step of performing a predetermined process on the object subjected to the projection exposure. 20. A device manufactured from an object subjected to projection exposure using the exposure apparatus according to claim 18.