JP6047433B2 - Deposition source crucible - Google Patents

Description

  The present invention relates to a vapor deposition source crucible used to heat a vapor deposition material to melt and evaporate it and deposit the evaporated molecules on a substrate surface to grow a thin film.

  FIG. 6 is a cross-sectional view showing a molecular beam source cell used in a thin film forming apparatus for forming a thin film on a substrate surface in a conventional vacuum chamber. In this molecular beam source cell, a deposition material a is accommodated in a bottomed cylindrical crucible 3 made of a thermally and chemically highly stable material, and the deposition material a is disposed outside the crucible 3. The heated electric heater 5 is used to melt and evaporate the vapor deposition material, and the generated evaporated molecules are discharged from the discharge port 4 and deposited on the substrate (see Patent Document 1). The heating temperature of the heater 5 that heats the crucible 3 from its outer periphery is controlled based on the output from the thermocouple 7 that measures the temperature at one or a plurality of positions such as the center of the bottom of the crucible 3. ing.

JP 2005-82833 A

  By the way, in the crucible 3 of the conventional molecular beam source cell as shown in FIG. 6 described above, the inside of the crucible 3 is heated by the heater 5 installed outside the crucible 3. As in the temperature distribution indicated by the dotted line, the vapor deposition material in the peripheral portion in the crucible 3 close to the heater 5 sufficiently increases the temperature within a relatively short time, whereas in the crucible 3 away from the heater 5 The temperature of the vapor deposition material in the central portion does not readily rise, and uneven temperature rise has occurred particularly between the peripheral side and the central side in the crucible 3.

  Therefore, especially when depositing non-metallic materials with low thermal conductivity, such as organic substances, and when using large crucibles in recent years, it takes a long time until the temperature of the entire deposition material in the crucible becomes uniform. There is a problem that the waiting time of the time is required, the waiting time is rate-determining, and the operating rate of the thin film forming apparatus is lowered. There is also a problem that a part of the vapor deposition material evaporates during the long waiting time described above, and the utilization efficiency of the vapor deposition material is reduced. Furthermore, in the vapor deposition material in the high temperature portion in the crucible 3 where the above-described temperature rise unevenness has occurred, the evaporation rate may be reduced due to material deterioration, and the like. There has also been a problem of deterioration of the quality of the thin film.

  The present invention has been made paying attention to such problems of the prior art, and prevents the deposition material in the crucible from being unevenly heated so that the deposition material in the crucible does not become uneven when heated by the heater. Shortens the waiting time until the temperature rises evenly, thereby improving the operating rate of the thin film forming equipment, improving the utilization efficiency of the vapor deposition material, and preventing the deterioration of the quality of the thin film formed on the substrate An object of the present invention is to provide a vapor deposition source crucible that can be used.

  A vapor deposition source crucible according to the present invention for solving such a problem is a vapor deposition source crucible for heating an internal vapor deposition material by heat from a heater disposed outside, and the inner wall surfaces of the crucibles are mutually connected. A plurality of linear metal rods or thin lines that connect the opposing portions are arranged so as to intersect with each other in a plan view and also intersect with each other in a side view.

  Further, in the vapor deposition source crucible according to the present invention, a plurality of metal rods, thin wires, or strips connecting the mutually facing portions of the inner wall surface of the crucible cross each other in a plan view, and in the vertical direction. You may arrange | position so that height may mutually differ.

  Further, in the vapor deposition source crucible according to the present invention, the one or more metal rods, thin wires or strips are arranged only in a region from a substantially central portion to a bottom portion in the vertical direction in the crucible. There may be.

  In the vapor deposition source crucible according to the present invention, the one or more metal bars, thin wires, or strips are fixedly or detachably disposed with respect to the inner wall surface of the crucible.

  In the present invention, one or a plurality of metal (including alloy) rods, thin wires, or strips are arranged so as to connect the inner wall surface of the crucible and the substantially central portion in the horizontal direction in the crucible. Therefore, the heat of the heater from the outside of the crucible is in contact with or joined to the inner wall surface of the crucible, and only the vapor deposition material on the inner wall surface side in the crucible is made of a metal rod, thin wire or strip with high thermal conductivity. In addition, it is efficiently transmitted to the vapor deposition material on the substantially central portion side, and the entire vapor deposition material in the crucible is heated uniformly and uniformly, so that the temperature of the entire vapor deposition material in the crucible rises evenly. The waiting time until it is warmed is greatly reduced than before. Therefore, according to the present invention, the waiting time until the temperature of the entire vapor deposition material in the crucible is uniformly raised is greatly reduced, and as a result, the operating rate of the thin film forming apparatus can be greatly improved. Therefore, it is possible to improve the utilization efficiency of the vapor deposition material without evaporating the vapor deposition material during the conventional long standby time, and further, it is heated to the high temperature in the crucible during the conventional long standby time. It is also possible to effectively prevent the deterioration of the vapor deposition material in the portion and the deterioration of the quality of the thin film formed on the substrate.

  Further, in the present invention, a plurality of metal bars, thin wires, or strips are crossed with each other in plan view so as to connect the mutually facing portions of the inner wall surface of the crucible, and the height in the vertical direction is When arranged differently from each other, a plurality of metal rods, fine wires, or strips can be stretched around the crucible in a so-called lattice pattern or mesh pattern. This makes it possible to reliably raise the temperature of the entire vapor deposition material in the crucible evenly without uneven temperature rise.

  Further, in the present invention, when the one or more metal rods, thin wires or strips are arranged only in the region from the substantially central portion to the bottom in the vertical direction in the crucible, in most cases In this case, the vapor deposition material is accommodated in the crucible in the region from the substantially central portion to the bottom in the vertical direction of the crucible, so that in most cases, the entire vapor deposition material in the crucible is heated uniformly. In addition, since a metal rod, a thin wire or a strip-like body is not disposed in the region from the substantially central portion in the vertical direction in the crucible to the upper discharge port, the vapor deposition material in the crucible is heated, When evaporated and the evaporated molecules move in the direction of the discharge port, an effect is obtained that the metal rod, thin wire or strip does not hinder the smooth movement.

  Furthermore, in the present invention, when the metal rod, thin wire, or strip is fixedly disposed on the inner wall surface of the crucible, for example, by welding, the metal rod, thin wire, or strip is placed in the crucible. The apparatus can be operated stably without worrying about dropping off, and the heat from the inner wall surface can be reliably transmitted to the entire crucible. On the other hand, in the present invention, when the metal rod, thin wire or strip is detachably disposed on the inner wall surface of the crucible, the metal rod, thin wire or strip can be easily removed from the crucible. As a result, crucible maintenance can be performed very easily.

(A) And (b) is the side view and front view which respectively show the external appearance of the vapor deposition source crucible which concerns on one Embodiment of this invention. (A) And (b) is the sectional side view and sectional drawing seen from the front of the vapor deposition source crucible of FIG. 1, respectively, (c) is the top view of the vapor deposition source crucible of FIG. It is a figure for demonstrating the content of the experiment which this inventor performed in order to confirm the effect of this embodiment. It is a figure for demonstrating the experimental result which this inventor performed in order to confirm the effect of this embodiment. (A) And (b) is a figure for demonstrating the vapor deposition source crucible which concerns on other embodiment of this invention, respectively. It is sectional drawing which shows the molecular beam source cell used for the thin film forming apparatus for forming a thin film on the substrate surface in the conventional vacuum chamber.

  Next, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are a side view and a front view showing the appearance of a vapor deposition source crucible according to an embodiment of the present invention, respectively, and FIGS. 2A and 2B are side sectional views of the present embodiment, respectively. Sectional view seen from the front, (c) is a plan view of the present embodiment.

  1 and 2, 11 is a bottomed cylindrical crucible having an electric heater (not shown) arranged on its outer peripheral surface, 11a is the inner wall surface of the crucible 11, 11b is the bottom of the crucible 11, and 12, 13 are the above-mentioned A metal rod 14 made of, for example, stainless steel disposed in the crucible 11 is an outlet that is formed above the crucible 11 and discharges evaporated molecules in the direction of the substrate (not shown).

  In the present embodiment, the respective metal rods 12 and 13 are fixed by welding their respective end portions to respective recesses or holes formed in mutually opposing portions of the inner wall surface 11 a of the crucible 11. That is, the end portions of the metal rods 12 and 13 are respectively recessed portions or holes on the surfaces of the inner wall surface 11a facing each other such that the metal rods 12 and 13 extend in the radial direction of the plane of the crucible 11. Are welded to each. Further, the metal rods 12 and the metal rods 13 are substantially perpendicular to each other when viewed from the plane (see FIG. 2C), and have different vertical heights when viewed from the side. (See FIGS. 2A and 2B).

  As described above, in the present embodiment, the metal rods 12 and 13 are connected to each other on the inner wall surface 11a of the crucible 11 so as to be substantially orthogonal to each other in plan view and in the vertical direction. Are welded and fixed to the inner wall surface 11a of the crucible 11 so that their heights are different from each other. Therefore, according to the present embodiment, since the plurality of metal rods 12 and 13 are stretched in a substantially lattice shape in the crucible 11, a heater (not shown) arranged outside the crucible 11 is shown. ) Can be evenly transmitted to the entire vapor deposition material in the crucible 11, and the entire vapor deposition material in the crucible 11 can be reliably heated without unevenness.

  The inventor conducted measurement experiments such as a waiting time until the entire vapor deposition material in the crucible 11 was heated uniformly to a predetermined temperature when the crucible 11 according to this embodiment was used. FIG. 3 shows the contents of this experiment. As shown in FIG. 3, thermocouples were provided in advance at a plurality of locations in the crucible, and the temperatures at the plurality of locations in the crucible during heating by the heater were measured.

  FIG. 4 is a diagram showing the experimental results. As shown in FIG. 4, when the crucible according to the present embodiment (represented as “current state” in FIG. 4) is used, the entire vapor deposition material in the crucible is heated up to the target temperature almost uniformly in 16 hours. . On the other hand, according to the results of experiments conducted by the present inventor using a conventional crucible, a waiting time of about 24 hours was required until the entire deposition material in the conventional crucible was heated up to the target temperature almost uniformly. . Therefore, by using the crucible according to the present embodiment, the waiting time can be shortened by about 30% or more compared to the conventional example.

  Next, FIG. 5 is a figure for demonstrating the example of the vapor deposition source crucible which concerns on other embodiment of this invention. In the example shown in FIG. 5 (a), the end portions of the metal rods 22 and 23 are welded to the respective portions of the inner wall surface 21a facing each other through the central axis C of the crucible 21 (this configuration is And substantially the same as the embodiment described above with reference to FIGS. In the example shown in FIG. 5A, the metal rods 22, 23 are only in the region from the substantially central portion to the bottom 21b in the vertical direction in the figure in the crucible 21 (see reference numeral A in FIG. 5A). However, they are arranged so as to be substantially orthogonal to each other in the horizontal view and so as not to overlap each other in the vertical direction in the figure, that is, so as to have a substantially lattice shape as a whole.

  Therefore, according to the example of FIG. 5A, in most cases, the portion where the vapor deposition material is accommodated in the crucible 21 is in the region from the substantially central portion in the vertical direction of the crucible 21 to the bottom portion 21b. Therefore, it is possible to raise the temperature of the entire vapor deposition material in the crucible 21 evenly in most cases. 5A, in the region from the substantially central portion of the crucible 21 in the vertical direction of the crucible 21 to the discharge port 24 (see symbol B in FIG. 5A), the metal rods 22, 23 is not disposed, the vapor deposition material in the crucible 21 is heated and evaporated to prevent the metal rods 22 and 23 from obstructing the smooth movement when the evaporated molecules move in the direction of the discharge port 24. The advantage is obtained.

  Further, in the example shown in FIG. 5B, in the crucible 31, in the illustrated vertical direction of the inner wall surface 31 a facing the portion 35 near the bottom portion 31 b of the inner wall surface 31 a and the portion 35 via the central axis C. For example, the ends of two metal rods 32 and 33 are welded and fixed to the portions 35 and 36, respectively, so as to connect the central portion 36. Thus, in the example shown in FIG. 5B as well, as in the example shown in FIG. 5A, the bottom 21b (or the part 35) from the substantially central portion 36 in the illustrated vertical direction in the crucible 31. The metal rods 32 and 33 are disposed only in the region up to (see the symbol A in FIG. 5B).

  Therefore, even in the example of FIG. 5B, in most cases, the portion in which the vapor deposition material is accommodated in the crucible 31 is from the substantially central portion 36 in the vertical direction of the illustration in the crucible 31 to the bottom 21b (or the above-described portion). Since it is in the region up to the portion 35) (see symbol A in FIG. 5B), in most cases, the entire vapor deposition material in the crucible 31 can be heated uniformly. Also in the example of FIG. 5B, a metal rod 32 is provided in the region from the substantially central portion 36 in the vertical direction of the crucible 31 to the discharge port 34 (see symbol B in FIG. 5B). , 33 are not disposed, the vapor deposition material in the crucible 31 is heated and evaporated to cause the metal rods 32, 33 to hinder the smooth movement when the evaporated molecules move in the direction of the discharge port 34. There is also a merit that it will disappear.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above, and various modifications and changes can be made. For example, in the above-described embodiment, the metal rods 12 and 13 are made of stainless steel. However, the material of the metal rods, thin wires, or strips in the present invention is not limited to this, and for example, copper, silver, Alternatively, various metal materials such as alloys can be used. Moreover, in the said embodiment, although the linear metal rod was shown as an example of a metal rod, a thin wire | line, or a strip | belt-shaped body, in this invention, it is not restricted to this, The metal curved by the complicated shape etc. You may make it arrange | position a manufacturing rod, a thin wire | line, or a strip | belt shaped object in a crucible. In the above embodiment, the plurality of metal rods are arranged in a crucible so as to form a substantially lattice shape as a whole by being substantially orthogonal to each other in plan view. However, the present invention is not limited to this. Instead, for example, a plurality of metal rods may be arranged in a crucible so that they cross each other at various angles in plan view and have a substantially net-like shape as a whole.

  Furthermore, in the above-described embodiment, each end of the metal rod is welded and fixed to the inner wall surface of the crucible. However, the present invention is not limited to this. For example, the inner wall surface of the crucible can be pressed and A metal thin wire or strip having a plurality of projecting portions formed so as to be elastically deformable in a direction protruding from the inner wall surface and a direction away from the inner wall surface, and a portion located on the center side in the horizontal direction in the crucible (In this case, during the insertion, the protruding portion abuts against and presses the inner wall surface of the crucible), or does not press the inner wall surface of the crucible at room temperature, but at a high temperature. A thin wire or strip made of shape memory alloy having a plurality of projecting portions formed so as to be deformable so as to press the inner wall surface of the crucible and a portion located on the center side in the horizontal direction of the crucible is detachable in the crucible. Insert (this If, contact with the inner wall surface of the projecting portion crucible in a high temperature during insertion, it may be pressed to) as.

11, 21, 31 Crucible 11a, 21a, 31a Inner wall surface 11b, 21b, 31b Bottom part 12, 13, 22, 23, 32, 33 Metal rod 14, 24, 34 Discharge port

Claims (1)

A vapor deposition source crucible for heating an internal vapor deposition material by heat from a heater arranged on the outside, and a plurality of linear metal rods or thin wires respectively connecting mutually facing portions of the inner wall surface of the crucible The vapor deposition source crucible is arranged so as to cross each other in a plan view and also cross in a side view .

Images