JP4875565B2 - Cap for crucible of molecular beam source cell - Google Patents

Description

The present invention is used to form a thin film by generating and emitting a molecular beam by heating and evaporating a desired vapor deposition material (molecular beam material) in a vacuum, and colliding and depositing the molecular beam on a substrate. The present invention relates to a crucible cap for a molecular beam source cell.

  Molecular beam epitaxy equipment (MBE equipment) puts a substrate in an ultra-high vacuum and heats it, and puts the material to be deposited as raw materials in different crucibles, heats them with a heater, evaporates them, and irradiates the substrate as molecular beams This is a device for crystal growth.

FIG. 14 is a diagram showing a conventional example of such an MBE apparatus (see Patent Document 1). In the conventional MBE apparatus shown in FIG. 14, crucibles 10 and 20 and a substrate 33 are arranged in a vacuum vessel (not shown). The crucibles 10 and 20 are filled with the evaporation materials a and b, respectively. The crucibles 10 and 20 are heated by the heaters 15, 16, 25 and 26 to evaporate each evaporation material, and evaporated molecules are emitted from the openings 14 and 24 of the crucibles 10 and 20 as molecular beams toward the substrate 33. As a result, a thin film is formed on the substrate 33. In the conventional example of FIG. 14, the crucible 10 disposed on the left side of the figure is filled with a vapor deposition material a as a main component, and when it is heated, it evaporates and the molecular beam is directed from the opening 14 of the crucible 10 toward the substrate 33. To be released. On the other hand, the crucible 20 arranged on the right side of the figure is filled with the vapor deposition material b as a subcomponent, and when it is heated, it evaporates and a molecular beam is emitted from the opening 24 of the crucible 20 toward the substrate 33. At that time, since the cap (closing member for closing the opening) 31 having a plurality of throttle holes 32 formed in the opening of the crucible 20 is fitted, the amount of the evaporated molecules is reduced to a predetermined amount. Are emitted as molecular beams.
JP 2003-34591 A

  By the way, in the conventional MBE apparatus as described above, the opening of each of the crucibles 10 and 20 is disposed so as to face the center of the substrate 33, and the vapor deposition material is heated in each of the crucibles 10 and 20. The evaporated molecules generated by evaporation are formed on the substrate 33 because they are emitted as molecular beams from the openings 14 and 24 of the crucibles 10 and 20 as they are or limited to a predetermined amount by the throttle hole 32. There is a problem that the thickness of the thin film formed on the substrate becomes non-uniform so that only the central portion of the substrate 33 is large and small in the peripheral portion away from the center of the substrate. there were.

The present invention has been made paying attention to such problems of the prior art, and can improve the uniformity of the film thickness of the thin film formed on the substrate at low cost, and further allows the deposition of organic materials. Therefore, an object of the present invention is to provide a crucible cap for a molecular beam source cell that can be used not only for vapor deposition of inorganic materials that require high-temperature processes.

A crucible cap of a molecular beam source cell according to the present invention for solving the above-described problems is obtained by heating the evaporated molecular beam material filled in the crucible and evaporating molecules generated by evaporation. A crucible cap for a molecular beam source cell that emits as a molecular beam in the direction of the substrate to be vapor-deposited, having a protruding portion that protrudes from the opening toward the substrate when attached to the opening of the crucible. And having a depth of 6 mm or more in the direction of the central axis of the opening when attached to the opening of the crucible, and from a substantially central portion of the lower surface of the cap to a side surface not facing the substrate. A plurality of throttle holes extending substantially radially so as to be directed to each other, wherein the plurality of throttle holes are inclined within a range of 15 to 60 degrees with respect to a central axis direction of the crucible opening when attached to the crucible opening. Aperture There has been formed, it is characterized in.

In the crucible cap of the molecular beam source cell according to the present invention, it is preferable that the throttle hole is formed so that the inner diameter thereof gradually increases along the traveling direction of the evaporated molecules.

Further, in the crucible cap of the molecular beam source cell according to the present invention, the outer shape of the crucible cap is such that the area of the cross section perpendicular to the central axis of the opening of the crucible gradually increases along the traveling direction of the evaporated molecules. It is desirable that it is formed.

Furthermore, the crucible cap of the molecular beam source cell according to the present invention is preferably integrally formed of a ceramic material.

  According to the present invention, a cap having a thickness of at least about 6 mm in the central axis direction of the opening is disposed in the opening of the crucible, and the central axis of the opening of the crucible is disposed inside the cap. A plurality of throttle holes inclined by about 15 to 60 degrees with respect to the direction in the direction from the approximate center of the bottom of the cap toward the outer periphery of the opening of the crucible or in the vicinity thereof (for example, the substrate to be deposited (particularly the periphery thereof) (In the direction toward the surface), it is formed so as to be substantially radial. Therefore, according to the present invention, the evaporated molecules are emitted as molecular beams in the direction of the substrate from the apertures of the cap, but the apertures of the crucibles (opposite the deposition target substrate), respectively. Is formed so as to be inclined by about 15 to 60 degrees with respect to the central axis of the substrate, so that the molecular beam is directed in the direction of the peripheral portion away from the central portion of the substrate (about 15 to 60 degrees with respect to the substrate surface). Only in a tilted direction). Actually, since the molecular beam travels while diffusing, not only the peripheral portion of the substrate but also the central portion is irradiated almost uniformly. Therefore, according to the present invention, it is possible to prevent the inconvenience that the thickness of the thin film deposited on the substrate is increased only in the central portion of the substrate and the peripheral portion is reduced, and the entire thin film formed on the substrate is prevented. The film thickness uniformity can be improved.

  In particular, in the present invention, when the inner diameter of the throttle hole of the cap is formed so as to gradually expand along the traveling direction of the evaporated molecules, the molecular beam emitted from the throttle hole is the inner diameter of the throttle hole. Since it progresses while expanding along the shape, the uniformity of the film thickness of the thin film formed on the substrate can be further improved.

  In the present invention, the outer shape of the cap is formed such that the area of a cross section perpendicular to the central axis of the opening gradually increases along the traveling direction of the evaporated molecules. The cap can be easily attached even when the vicinity of the lower part of the opening of the crucible is formed in a tapered shape whose inner diameter gradually increases toward the substrate.

  Furthermore, in the present invention, when the cap is integrally formed of a known heat-resistant ceramic material, the cap can be manufactured at a very low cost and only for the vapor deposition of an organic material. In addition, an effect is obtained that it can be used for vapor deposition of inorganic materials that require heating the crucible to a high temperature.

  The best mode for carrying out the present invention is a mode as described in Example 1 below.

  FIG. 1 (a) is a side sectional view showing a crucible used in the molecular beam source cell according to Example 1 of the present invention, and FIG. 1 (b) is a crucible shown in FIG. FIG. 2 (a) is a plan view showing a cap 2 arranged in the opening of the crucible of FIG. 1, FIG. 2 (b) is a side sectional view of the cap 2, and FIG. 2 (c). FIG. 3A is a perspective view showing the cap 2 obliquely from above, and FIG. 3B is a perspective view showing the cap 2 obliquely from below.

  1 (a) and 1 (b), 1 is a bottomed, substantially cylindrical crucible, 1a is an opening of the crucible 1, and 1b is formed with an inner diameter in the vicinity of the opening 1a of the crucible 1 smaller than other portions. The tie-down part. In the first embodiment, the crucible 1 is arranged in a vacuum vessel (not shown) so that the opening 1a faces the deposition target substrate (not shown). In the first embodiment, the lower vicinity 1c of the opening 1a of the crucible 1 is formed in a tapered shape whose inner diameter gradually increases upward in the figure.

  2A, 2B, and 2C, reference numeral 2 denotes a cap that is placed in the opening 1a of the crucible 1 and is integrally formed of, for example, a ceramic material, and 2a is formed substantially radially inside the cap 2. The plurality of throttle holes 2b are common holes formed in the bottom 2c of the cap 2 so as to be continuous with the illustrated lower portion of each throttle hole 2a. In the first embodiment, the evaporated molecules generated by heating and evaporating the molecular beam material in the crucible 1 pass through the common hole 2b of the cap 2 and the respective constricted holes 2a. Is emitted toward the substrate.

  In the first embodiment, the cap 2 is formed so that its vertical thickness (thickness in the direction of the central axis A of the opening 1a of the crucible 1) is, for example, 8.6 mm. Therefore, in the first embodiment, the aperture 2a formed in the cap 2 has a length sufficient to give directivity to the molecular beam irradiated to the substrate.

  Further, in the first embodiment, the throttle hole 2a of the cap 2 is inclined by, for example, about 45 degrees with respect to the illustrated vertical direction of the cap 2 (the direction of the central axis A of the opening 1a of the crucible 1). Is formed. Further, in the first embodiment, a total of 12 throttle holes 2a are directed from the approximate center of the constricted portion 1b in the vicinity of the opening 1a of the crucible 1 toward the outer periphery of the opening 1a or in the vicinity thereof (on the deposition substrate). In a direction toward the peripheral part), it is formed substantially radially. That is, in the first embodiment, each of the throttle holes 2a extends from the common hole 3b of the cap 2 in an obliquely upward direction (a direction gradually approaching the outer periphery), and a part of the upper surface of the cap 2 ( Open to the side near the outer periphery.

  As described above, in Example 1, the evaporated molecules generated in the crucible 1 are given directivity so as to go to the peripheral part of the substrate instead of the central part of the substrate when passing through the throttle hole 2a. Released as a molecular beam. In the first embodiment, the inner diameters of the respective throttle holes 2a are all formed substantially the same. Further, in the first embodiment, the cap 2 has an outer diameter in the upward direction in the figure (corresponding to the substrate) so as to correspond to the tapered inner wall surface of the lower vicinity 1c of the opening 1a of the crucible 1. It is formed in a tapered shape that gradually expands along the direction (see FIG. 2B).

  As described above, in the first embodiment, the cap 2 having a thickness of, for example, 8.6 mm is disposed in the opening 1a of the crucible 1, and the cap 2 has a direction toward the substrate (the crucible 1 A plurality of apertures 2a are formed which are inclined by, for example, about 45 degrees with respect to the central axis A direction of the opening 1a. Therefore, in the first embodiment, the evaporated molecules generated by heating and evaporating the molecular beam material in the crucible 1 are given a predetermined length (giving directivity) in each throttle hole 2a in the cap 2. For example, a directivity is given not only to the center part of the substrate but also to the peripheral part of the substrate and emitted as a molecular beam (for example, Patent Document 1). The restriction hole 32 formed in the closing member 31 has a very short length, so that directivity cannot be given to the molecular beam). Therefore, according to the first embodiment, vapor deposition molecules (molecular beams) can be collided and deposited almost uniformly over the periphery and center of the substrate, and a thin film having a substantially uniform film thickness on the substrate surface. Can be formed. In the first embodiment, since the cap 2 is integrally formed of a known ceramic material, it can be manufactured at a very low cost and can withstand high temperatures such as 1,700 ° C. It can be used not only for the deposition of materials but also for the deposition of inorganic materials that require high temperature processes.

  In addition, this inventor is the case where the cap 2 is attached to the crucible 1 and a metal thin film such as Ag is formed on the substrate, and the case where the metal thin film is formed on the substrate without attaching the cap 2 (both are molecular beams) An experiment was conducted in which the film thickness distribution shape was measured and compared at a deposition rate of 0.5 mm / s). FIG. 4 is a graph showing the results. FIG. 4 shows film thickness distribution shapes when the cap 2 is used and when the cap 2 is not used. As shown in FIG. 4, when the cap 2 is not used, the film thickness becomes relatively abrupt as the distance from the cell center (the position where the central axis A of the opening 1a of the crucible 1 intersects the substrate) increases. When the cap 2 is used, the film thickness distribution decreases relatively slowly even when the distance from the cell center is increased (the film thickness distribution shape is improved from N = 3). ) Therefore, it was confirmed that the uniformity of the film thickness distribution of the thin film formed on the substrate can be improved by using the cap 2 of Example 1.

  Next, FIG. 5 (a) is a side sectional view showing a crucible used in the molecular beam source cell according to Example 2 of the present invention, and FIG. 5 (b) shows a later-described cap on the crucible of FIG. 5 (a). FIG. 6 (a) is a plan view showing a cap disposed in the opening of the crucible in FIG. 5, FIG. 6 (b) is a side sectional view thereof, and FIG. 6 (c) is a sectional view thereof. FIG. 6 (d) is a side view (inner drawing hole is indicated by a broken line and a one-dot chain line), and FIG. 7 (a) is a perspective view showing a cap used in the second embodiment obliquely from above. FIG. 7B is a perspective view showing the cap obliquely from below.

  5-7, the same code | symbol is attached | subjected to the part which is common in FIGS. 1-3, and description is abbreviate | omitted. 5 to 7, reference numeral 3 denotes a cap which is disposed in the opening 1 a of the crucible 1 and is integrally formed of, for example, a ceramic material, 3 a is a plurality of throttle holes formed inside the cap 3, and 3 b is the cap 3. This is a common hole formed in the center of the bottom 3c and continuous with the illustrated lower part of each throttle hole 3a. In the second embodiment, the molecular beam generated by heating and evaporating the molecular beam material in the crucible 1 passes through the common hole 3b of the cap 3 and the respective constricted holes 3a. And discharged toward the substrate.

  In the second embodiment, the cap 3 is formed so that its vertical thickness (thickness in the direction of the central axis A of the opening 1a of the crucible 1) is 12.6 mm, for example. Therefore, in the second embodiment, each throttle hole 3a formed in the cap 3 has a predetermined length (sufficient to give directivity to the molecular beam emitted from the opening 1a of the crucible 1). Length) is secured. In the second embodiment, each throttle hole 3a of the cap 3 is inclined by, for example, about 45 degrees with respect to the illustrated vertical direction of the cap 3 (the direction of the central axis A of the opening 1a of the crucible 1). (See FIG. 6B). In the second embodiment, a total of twelve throttle holes 3a are formed substantially radially in the direction from the center of the constricted portion 1c of the crucible 1 toward the deposition target substrate. That is, in the second embodiment, each of the throttle holes 3a extends from the common hole 3b of the cap 3 in an obliquely upward direction (a direction gradually approaching the outer periphery), and the side surface of the upper portion of the cap 3 in the figure. 3d and a part of upper surface 3e are opened.

  As described above, in Example 2, the evaporated molecules generated in the crucible 1 are molecular beams that are given directivity so as to go to the peripheral part of the substrate instead of the central part of the substrate by the throttle hole 3a. Released. In the second embodiment, the inner diameters of the throttle holes 3a are all the same. Further, as shown in FIG. 6 (b), the lower part of the cap 3 shown in the figure has an outer diameter corresponding to the tapered inner wall surface of the lower vicinity 1c of the opening 1a of the crucible 1. It is formed in a tapered shape that gradually expands along the upward direction (the direction of the substrate).

  As described above, in the second embodiment, the cap 3 having a thickness of 12.6 mm, for example, is disposed in the opening 1a of the crucible 1, and the cap 3 has a substrate direction (opening of the crucible 1). A plurality of throttle holes 3a inclined by about 45 degrees, for example, with respect to the central axis A direction of the portion 1a are formed substantially radially. Therefore, in the second embodiment, the evaporated molecules generated by heating and evaporating the molecular beam material in the crucible 1 have a predetermined length (giving directivity) in each throttle hole 3a in the cap 3. (A sufficient length), the directivity is given to the peripheral portion of the substrate, not to the central portion of the substrate, and it is emitted as a molecular beam. Even if the molecular beam is given directivity in the direction of the peripheral part of the substrate in this way, in fact, the molecular beam gradually diffuses on the way to the substrate, so the molecular beam is only in the peripheral part of the substrate. It collides almost evenly in the center and accumulates. Therefore, according to the second embodiment, it is possible to deposit the vapor deposition molecules by colliding the molecular beam substantially uniformly with the peripheral portion and the central portion of the substrate, so that a thin film having a substantially uniform film thickness is formed on the substrate surface. can do. In the second embodiment, since the cap 3 can be integrally formed with a known ceramic material, it can be manufactured at a very low cost and can withstand high temperatures such as 1,700 ° C., so that only organic material is deposited. It can also be used for vapor deposition of inorganic materials that require high temperature processes.

  Next, FIG. 8 is a side sectional view showing a cap used in the molecular beam source cell according to Embodiment 3 of the present invention. In the third embodiment, as shown in FIG. 8, the structure of the cap 4 disposed in the opening 1a of the crucible 1 is different from the first embodiment, and the other basic configuration is the first embodiment. It is the same. The cap 4 used in the third embodiment has an inner shape (inner wall surface) of a plurality of throttle holes 4a extending obliquely upward (and radially) in FIG. 8 from a common hole 4b formed at the center of the bottom portion 4c. However, it is not a straight shape like the throttle hole 2a of the first embodiment (see FIG. 2B), but is characterized in that it is formed in a tapered shape in which the inner diameter gradually increases along the traveling direction of the evaporated molecules. There is.

  In the third embodiment, since each throttle hole 4a is tapered as described above, evaporated molecules passing through each throttle hole 4a have directivity in the process of passing through each throttle hole 4a. Are simultaneously diffused along the tapered inner wall surface and emitted as molecular beams toward the substrate. Therefore, according to the third embodiment, molecular beams collide evenly with the substrate surface, and the uniformity of the film thickness of the thin film on the substrate can be further improved.

  Next, FIG. 9 is a side sectional view showing a cap used in the molecular beam source cell according to Embodiment 4 of the present invention. In the fourth embodiment, as shown in FIG. 9, the configuration of the cap 5 disposed in the opening 1a of the crucible 1 is different from the second embodiment, and the other basic configuration is the second embodiment. It is the same. The cap 5 used in the fourth embodiment has an inner shape (inner wall surface) of a plurality of throttle holes 5a extending obliquely upward (and radially) in FIG. 9 from a common hole 5b formed at the center of the bottom 5c. However, it is not a straight shape (see FIG. 6B) like the throttle hole 3a of the second embodiment, but is characterized in that it is formed in a tapered shape in which the inner diameter gradually increases along the traveling direction of the evaporated molecules. There is.

  In the fourth embodiment, since each throttle hole 5a is tapered as described above, the evaporated molecules passing through each throttle hole 5a have directivity in the process of passing through each throttle hole 5a. Are simultaneously diffused along the tapered inner wall surface and emitted as molecular beams toward the substrate. Therefore, according to the fourth embodiment, molecular beams collide evenly with the substrate surface, and the uniformity of the film thickness of the thin film on the substrate can be further improved.

  Next, FIG. 10 is a side sectional view showing a cap used in the molecular beam source cell according to Embodiment 5 of the present invention. In the fifth embodiment, as shown in FIG. 10, only the outer shape of the cap 6 arranged in the opening 1a of the crucible 1 is different from that of the first embodiment, and the other basic configuration is the first embodiment. It is the same. In the fifth embodiment, the outer shape of the cap 6 is formed in a cylindrical shape. This is because the shape of the lower portion (see 1c in FIG. 1) of the opening 1a of the crucible 1 to which the cap 6 is mounted is not a taper as shown in FIG. 1 but a straight cylindrical shape. Assuming the case, the outer shape of the cap 6 is formed so as to be adapted thereto. A plurality of throttle holes 6a are formed in the cap 6 so as to extend obliquely upward (and radially) in FIG. 10 from a common hole 6b formed in the center of the bottom 6c. The same as in the first embodiment. Therefore, the same effects as those of the first embodiment can be achieved by the fifth embodiment.

  Next, FIG. 11 is a side sectional view showing a cap used in the molecular beam source cell according to Embodiment 6 of the present invention. In the sixth embodiment, as shown in FIG. 11, only the outer shape of the cap 7 disposed in the opening 1a of the crucible 1 is different from that of the second embodiment, and the other basic configuration is the second embodiment. It is the same. In the sixth embodiment, the outer shape of the cap 7 is formed in a cylindrical shape. This is because the shape of the vicinity of the lower part of the opening 1a of the crucible 1 to which the cap 7 is mounted (see 1c in FIG. 5) is not a tapered shape as shown in FIG. In this case, the outer shape of the cap 7 is formed so as to match it. A plurality of throttle holes 7a are formed in the cap 7 so as to extend obliquely upward (and radially) in FIG. 11 from a common hole 7b formed in the center of the bottom 7c. The same as in the second embodiment. Therefore, the same operational effects as those of the second embodiment can be achieved by the sixth embodiment.

  Next, FIG. 12 is a side sectional view showing a cap used in the molecular beam source cell according to Embodiment 7 of the present invention. In the seventh embodiment, as shown in FIG. 12, only the outer shape of the cap 8 arranged in the opening 1a of the crucible 1 is different from the third embodiment, and the other basic configuration is the third embodiment. It is the same. In the seventh embodiment, the outer shape of the cap 8 is formed in a cylindrical shape. This is because the shape of the vicinity of the lower part of the opening 1a of the crucible 1 to which the cap 8 is mounted (see 1c in FIG. 1) is not a tapered shape as shown in FIG. In this case, the outer shape of the cap 8 is formed so as to be adapted thereto. Note that the inner diameter of the cap 8 gradually increases along the traveling direction of the evaporated molecules from the common hole 8b formed in the center of the bottom portion 8c toward diagonally upward (and radially) in FIG. A plurality of aperture holes 8a to be formed are formed. This is the same as in the third embodiment. Therefore, the same operational effects as those of the third embodiment can be achieved by the seventh embodiment.

  Next, FIG. 13 is a side sectional view showing a cap used in the molecular beam source cell according to Example 8 of the present invention. In the eighth embodiment, as shown in FIG. 13, only the outer shape of the cap 9 arranged in the opening 1a of the crucible 1 is different from the fourth embodiment, and the other basic configuration is the fourth embodiment. It is the same. In the eighth embodiment, the outer shape of the cap 9 is formed in a cylindrical shape. This is because the shape of the vicinity of the lower part of the opening 1a of the crucible 1 to which the cap 9 is mounted (see 1c in FIG. 5) is not a tapered shape as shown in FIG. In this case, the outer shape of the cap 9 is formed so as to match it. Note that the inner diameter of the cap 9 gradually increases along the traveling direction of the evaporated molecules from the common hole 9b formed in the center of the bottom portion 9c toward diagonally upward (and radially) in FIG. A plurality of throttle holes 9a are formed. This is the same as in the fourth embodiment. Therefore, the same operational effects as those of the fourth embodiment can be achieved by the eighth embodiment.

  The embodiments of the present invention have been described above. However, the present invention and the constituent elements constituting the present invention are limited to those described as the respective embodiments and the respective elements constituting the respective embodiments, respectively. Various modifications and changes are possible. For example, in the first embodiment, an example in which the cap 2 is manufactured from a known ceramic material is shown. However, the first embodiment is not limited to this, and for example, the cap 2 is manufactured from a known metal material. Of course, it is also good.

  Moreover, in the said Examples 1-8, the thickness of the direction of the central axis A of the said opening part 1a of the caps 2, 3, 4, 5, 6, 7, 8, and 9 arrange | positioned at the opening part 1a of the crucible 1 is set. Although it was set to 8.6 mm (Example 1 etc.) or 12.6 mm (Example 2 etc.), in this invention, it is not restricted to these. That is, in the present invention, the cap is long enough to give sufficient directivity to the evaporated molecules passing through the throttle holes 2a, 3a, 4a, 5a, 6a, 7a, 8a, 9a. Therefore, the thickness of the cap may be any thickness as long as it has a thickness of about 6 mm or more. In addition, since the cap is intended to close the opening, the thickness of the cap should be kept in a common sense range and from the viewpoint of manufacturing cost, the cap in the present invention is too thick. The thickness should not be adopted (thickness that can secure a sufficient length for the evaporating molecules passing therethrough in the throttle hole is sufficient). The thickness of the cap in the invention may be formed so as to have a thickness of about 6 to 15 mm, and it is desirable.

  Moreover, in the said Examples 1-8, each aperture hole 2a, 3a, 4a, 5a, 6a, 7a, 8a, formed in the inside of the said cap 2,3,4,5,6,7,8,9, 9a is formed so as to be inclined by approximately 45 degrees with respect to the direction of the central axis A of the opening 1a from the approximate center of the constricted portion 1c of the crucible 1 toward the outer periphery of the opening 1a. However, the present invention is not limited to this, and it suffices that the molecular beam emission direction is not the center of the substrate but the peripheral portion of the substrate. What is necessary is just to form so that it may incline within the range of about 15-60 degrees (more desirably within the range of about 30-50 degrees) with respect to the central axis A direction of the said opening part 1a, and it is desirable.

(A) is a sectional side view showing a crucible used in the molecular beam source cell according to Example 1 of the present invention, and (b) is a sectional side view showing a state where a cap is attached to the crucible of (a). (A) is a top view which shows the cap used for the present Example 1, (b) is the sectional side view, (c) is the figure which shows the bottom face. (A) is a perspective view which shows the cap used for the present Example 1 from diagonally upward, (b) is a perspective view which shows the cap from diagonally downward. 6 is a graph for explaining the operational effects of the first embodiment. (A) is a sectional side view which shows the crucible used for the molecular beam source cell which concerns on Example 2 of this invention, (b) is a sectional side view which shows the state which mounted | wore the crucible of (a). (A) is a plan view showing a cap used in the second embodiment, (b) is a sectional side view thereof, (c) is a diagram showing a bottom surface thereof, (d) is a side view thereof (with an internal throttle hole). (Indicated by a dashed line and a dashed line). (A) is a perspective view which shows the cap used for the present Example 2 from diagonally upward, (b) is a perspective view which shows the cap from diagonally downward. The sectional side view which shows the cap used for Example 3 of this invention. The sectional side view which shows the cap used for Example 4 of this invention. The sectional side view which shows the cap used for Example 5 of this invention. Side sectional drawing which shows the cap used for Example 6 of this invention. The sectional side view which shows the cap used for Example 7 of this invention. The sectional side view which shows the cap used for Example 8 of this invention. The figure for demonstrating the conventional molecular beam source cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crucible 1a Opening part 1b Constriction part 1c The downward vicinity part of an opening part (constriction part and taper-shaped part)
2, 3, 4, 5, 6, 7, 8, 9 Cap 2a, 3a, 4a, 5a, 6a, 7a, 8a, 9a Restriction hole 2b, 3b, 4b, 5b, 6b, 7b, 8b, 9b Common hole 2c, 3c, 4c, 5c, 6c, 7c, 8c, 9c Cap bottom 3d Cap side surface 3e Cap top surface

Claims (4)

This is a crucible cap for a molecular beam source cell that releases evaporated molecules generated by heating and evaporation of the molecular beam material filled in the crucible as molecular beams from the opening of the crucible toward the deposition target substrate. And
Having a protruding portion that protrudes from the opening toward the substrate when attached to the opening of the crucible;
When attached to the opening of the crucible, it has a depth of 6 mm or more in the direction of the central axis of the opening, and extends from a substantially central portion of the lower surface of the cap to a side surface of the protruding portion that does not face the substrate. A plurality of squeezing holes extending radially, wherein a plurality of squeezing holes are formed that are inclined within a range of 15 to 60 degrees with respect to a central axis direction of the opening of the crucible when attached to the opening of the crucible. Being
A crucible cap for a molecular beam source cell. 2. The crucible cap for a molecular beam source cell according to claim 1, wherein the throttle hole is formed so that the inner diameter thereof gradually increases along the traveling direction of the evaporated molecules . 2. The outer shape according to claim 1, wherein the outer shape of the crucible is formed such that an area of a cross section perpendicular to the central axis of the opening of the crucible gradually increases along the traveling direction of the evaporated molecules. Cap for crucible of molecular beam source cell. 2. The crucible cap for a molecular beam source cell according to claim 1, wherein the whole is integrally formed of a ceramic material .

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