JP4609991B2 - Solid material vaporizer - Google Patents

Description

  The present invention relates to a solid raw material vaporizer, and more particularly to a solid raw material vaporizer in which the side shape of a raw material container is devised.

In manufacturing a semiconductor device, a method of vaporizing a solid material and depositing a thin film or the like is often employed. For example, it is required to deposit thin films (several nm to several μm) of various materials such as W, Al, Cu, Ta, TaN, TiN, SiO ₂ , SiOC, and SiN with good coverage.

  For example, when manufacturing a semiconductor device, it may be necessary to form a barrier metal with a thin and uniform film thickness using a solid material. This specific example will be described below.

  That is, Cu (copper) wiring is introduced to reduce the wiring resistance of the semiconductor device. However, when forming a Cu wiring in a semiconductor device, the element characteristics deteriorate due to the diffusion of Cu into Si, the workability deteriorates due to poor adhesion to the insulating film, and the oxide is oxidized without forming a passive oxide film. Therefore, it is necessary to solve problems such as deterioration of wiring characteristics due to the progress to the inside. As one means for solving these problems, a barrier metal is provided at the interface between Cu and the wiring interlayer film. As the barrier metal, a single layer film or a multilayer film such as Ta or TaN is used, and a sputtering method is conventionally used as the film formation method.

  The barrier metal is indispensable for forming the Cu wiring as described above, and there is a minimum film thickness for solving the above problems. On the other hand, since the barrier metal having a high specific resistance increases the resistance of the Cu wiring, it is necessary to make the thickness of the barrier metal as thin as possible from the viewpoint of increasing the speed of the element. It is desirable to deposit.

  A chemical vapor deposition (CVD) method is known as a method suitable for such a requirement. In the chemical vapor deposition method, when a solid material having a low vapor pressure is used, it is common to increase the vapor pressure by heating in order to ensure a sufficient amount for film growth.

FIG. 9 is a schematic view illustrating a conventional solid material vaporizer. 9A is a schematic longitudinal cross-sectional view of the solid raw material vaporizer, and FIG. 9B is a schematic cross-sectional view taken along line AA ′ of FIG. 9A.
The conventional solid material vaporizer 1000 includes a material container 110 that houses the solid material 100, a gas inlet 120 that is supplied into the material container 110, and a gas outlet 130. The solid material 100 in the material container 110 is heated and vaporized by the heater 140 provided around the material container 110. Then, a mixed gas of the carrier gas supplied from the gas inlet 120 into the raw material container 110 and the vaporized gas is supplied from the gas outlet 130 into a heat treatment apparatus (not shown).

  As shown in the figure, the cross-sectional shape of the raw material container 110 along the line A-A ′ is circular.

  The present inventor conducted an experiment on the course of consumption of a solid material in a conventional solid material vaporizer.

  FIG. 10 is a schematic view illustrating an intermediate process in which a solid material is consumed in a conventional solid material vaporizer.

  FIG. 10A is a schematic view illustrating the course of consumption of a solid material having a low vapor pressure. As shown in the figure, according to this conventional solid material vaporizer 1000, it was found that the solid material 100 having a low vapor pressure is preferentially consumed from the vicinity of the side wall of the material container 110. That is, it has been found that a temperature gradient occurs between the portion of the solid material 100 in the vicinity of the heater 140 and the central portion of the solid material 100 in terms of heat conduction. In the case of a solid raw material having a low vapor pressure, the raw material partial pressure in the container is originally low, so that it is not easily affected by a reduction in the raw material partial pressure caused by the carrier gas.

  As a result, when the solid raw material 100 is further consumed and does not come into contact with the raw material container 110, the solid raw material 100 becomes difficult to be heated and is not vaporized, and there is a problem that generation of vaporized gas becomes unstable.

  That is, when vaporizing a solid raw material having a low vapor pressure in a conventional solid raw material vaporizer, the vaporization rate is slow because the thermal conductivity in the solid raw material is low, and the solid raw material is not consumed uniformly throughout the entire area, so that vaporized gas is generated. Was unstable.

  FIG. 10B is a schematic view illustrating the course of the consumption of the solid material having a high vapor pressure in the conventional solid material vaporizer. As shown in the figure, it was found that the solid raw material 100 having a high vapor pressure is preferentially consumed in the portion where the carrier gas hits. That is, it was found that the solid raw material 100 having a high vapor pressure is vaporized even at a relatively low temperature, and thus is not significantly affected by the temperature gradient in the solid raw material 100 and depends on the partial pressure of the solid raw material. Therefore, it is preferentially consumed from the portion where the raw material partial pressure is lowered by the carrier gas.

  That is, in the conventional solid material vaporizer, when vaporizing a solid material having a high vapor pressure, the generation of vaporized gas was unstable because the partial pressure of the solid material was not uniform throughout the entire area.

Moreover, in order to solve such a problem, a solid material vaporizer that has been devised to increase the surface area of the solid material in the material container has also been proposed (see, for example, Patent Document 1). In this proposal, the solid raw material is formed into a film, the back surface thereof is covered with a non-reactive support object, and the other surface is exposed to the atmosphere to form a sublimation surface.
Japanese Patent Laid-Open No. 10-025576

However, it takes time to form a solid raw material in the form of a film, cover the back surface with a non-reactive support object, and expose the other surface to the atmosphere to form a sublimation surface.
That is, in the conventional solid raw material vaporizer, the supply of vaporized gas becomes unstable due to temperature difference and pressure difference in the solid raw material, and the heat transfer efficiency of the heater and the gas efficiency of the carrier gas Therefore, the problem was that the vapor pressure of the solid raw material was not increased efficiently.
Further, if the solid raw material is heated too much, problems such as decomposition of the solid raw material occur, so there is an upper limit on the heating temperature, and there is a problem that the solid raw material cannot be supplied sufficiently.

  This invention is made | formed based on recognition of this subject, The objective is to provide the solid raw material vaporizer which can supply vaporized gas stably efficiently.

In order to achieve the above object, according to one aspect of the present invention,
A raw material container for containing a solid raw material;
A gas inlet for introducing gas into the raw material container;
A gas outlet for discharging gas from the raw material container;
With
A solid raw material vaporizer is provided in which the side wall of the internal space of the raw material container has a portion protruding inward.

According to another aspect of the present invention,
A raw material container for containing a solid raw material;
A gas inlet for introducing gas into the raw material container;
A gas outlet for discharging gas from the raw material container;
A heater provided around the raw material container;
With
The internal space of the raw material container has a substantially columnar shape,
A side wall of the internal space has a portion protruding inward, and a solid material vaporizer is provided.

In these solid raw material vaporizers, the outer periphery of the horizontal cross section of the internal space can be longer than the outer periphery of a circle having an area equal to the area of the cross section.
Moreover, the part protruded toward the inside may be formed in a curved shape.

Further, the portion protruding toward the inside is continuous in the vertical direction of the container,
It said side wall has a projecting portion to a plurality of said inner, between them, have a protruding part towards the outside,
Near the center of the upper surface of the internal space, either the gas inlet or the gas outlet is provided,
One of the gas inlet and the gas outlet may be provided toward a space formed by the portion protruding toward the outside .
Moreover, the part protruded toward the said outer side shall protrude in a curved surface shape.

Further, the portion protruding toward the inside is continuous in the vertical direction of the container,
The side wall is provided with a plurality of portions protruding toward the outside,
Near the center of the upper surface of the internal space, either the gas inlet or the gas outlet is provided,
One of the gas inlet and the gas outlet may be provided toward each of the spaces formed by the plurality of portions protruding toward the outside.

  ADVANTAGE OF THE INVENTION According to this invention, the solid raw material vaporization apparatus which can vaporize a solid raw material efficiently and can supply vaporization gas stably can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view illustrating a cross-sectional structure in a vertical direction of a solid material vaporizer according to an embodiment of the present invention.
The solid raw material vaporizer 1 of the present embodiment includes a raw material container 11 that houses the solid raw material 10, a gas inlet 12 that is supplied into the raw material container 11, and a gas outlet 13. Also in the solid raw material vaporizer 1 of the present embodiment, the solid raw material 10 in the raw material container 11 is heated and vaporized by the heater 14 provided around the raw material container 11. Then, the mixed gas of the carrier gas and the vaporized gas supplied from the gas inlet 12 into the raw material container 11 is supplied from the gas outlet 13 into a heat treatment apparatus (not shown).

Examples of the solid raw material 10 include powdered pentadimethylamino tantalum (Ta [N (CH ₃ ) ₂ ] ₅ : PDMAT). When this material is vaporized and supplied onto the substrate simultaneously or alternately with ammonia (NH ₃ ), a thin film of TaN (titanium nitride) can be formed.

  FIG. 2 is a schematic view illustrating the cross-sectional structure in the horizontal direction of the solid material vaporizer according to this embodiment. That is, this figure shows a cross-sectional structure taken along the line A-A 'of the solid material vaporizer shown in FIG.

  As shown in FIG. 2, the side wall of the raw material container 11 has a star shape and has a plurality of portions 11 </ b> R protruding inward. Between the portions 11R protruding toward the inside, a portion 11P protruding toward the outside is provided. Moreover, the cross-sectional shape of the container 11 illustrated in FIG. 2 is substantially symmetrical with respect to the center point 11C of the container.

  The outer periphery of the cross section of the side wall of the raw material container 11 is larger than the circumference of a circle having the same area. Therefore, the side wall area of the raw material container 11 in the embodiment of the present invention is larger in the area of the container side wall than the cylindrical container having the same bottom area and the same height as the raw material container 11.

  As described above, the plurality of inwardly protruding portions 11R are provided on the side wall of the raw material container 11, and the outer periphery of the cross section of the side wall is made larger than the circumference of a circle having the same area. The area of the side wall is increased. That is, the contact area of the solid raw material 10 in the raw material container 11 to the side wall of the raw material container 11 is increased. Thereby, since the heating area of the solid raw material 10 by the heater 14 provided around the raw material container 11 is increased, heat conduction to the solid raw material 10 is increased. As a result, the solid raw material 10 is heated in a large area with the same heater heat amount, and the amount of vaporization increases. That is, the supply amount of the vaporized gas can be increased.

  That is, according to the solid raw material vaporizer of this embodiment, the solid raw material is devised by devising the shape of the side wall so that the outer periphery of the horizontal cross section of the raw material container 11 is larger than the circumference of a circle having the same area. The facing area with respect to 10 heaters can be increased, and the supply amount of vaporized gas can be increased. Further, since the supply amount of the vaporized gas is increased, there is no possibility of causing a shortage of vaporized gas in the heat treatment apparatus.

  That is, since the vaporized gas can be stably supplied into the heat treatment apparatus, a uniform thin film can be deposited on the semiconductor substrate.

  As a result, for example, deterioration of device characteristics due to diffusion of Cu into Si, deterioration of workability due to poor adhesion to the insulating film, and oxidation progresses to the inside without forming a passive oxide film. Therefore, it is possible to form a highly reliable barrier metal that can prevent the deterioration of wiring characteristics due to the above.

  Hereinafter, other specific examples of the solid raw material vaporizer of the present invention will be described.

First, some specific examples regarding the shape of the side wall of the raw material container 11 will be described.
FIG. 3 is a schematic view illustrating a horizontal sectional structure of a solid material vaporizer as a second specific example of the invention. That is, FIG. 3 corresponds to the horizontal cross-sectional structure taken along the line AA ′ of the solid raw material vaporizer shown in FIG.
As shown in the drawing, the cross section taken along the line AA ′ of the raw material container 11 in this specific example also has a plurality of portions 11R protruding toward the inside. A portion 11P protruding outward is provided between the portions 11R protruding inward. Compared with the cross-sectional structure described above with reference to FIG. 2, the outer periphery of the cross section in this specific example, that is, the side wall, has a shape that combines arcs, and round concave portions 11 </ b> R and convex portions 11 </ b> P are alternately continuous. Yes.

  Also in this example, since the outer periphery of the cross section of the raw material container 11 is larger than the circumference of a circle having the same area, the same effect as that obtained in the above-described embodiment can be obtained.

  Furthermore, in this embodiment, since the outer periphery of the cross section is rounded, there is little possibility of disturbing or preventing the gas flow. Further, since the portion 11P that protrudes outward is formed in a curved surface shape, there is no possibility that gas flows in the corner near the tip. As a result, the efficiency of gas convection and the efficiency of heat convection due to the heating of the heater can be improved, the temperature difference and pressure difference in the solid raw material 10 can be reduced, and the supply amount of vaporized gas can be increased efficiently. .

  Thus, according to this specific example, the shape of the side surface is devised so that the outer periphery of the cross section of the raw material container 11 is larger than the circumference of a circle having the same area, and in particular, the side wall has a rounded shape. By doing this, while increasing the heating area of the solid raw material 10, the supply amount of vaporization gas can be increased efficiently.

4 to 6 are schematic views illustrating the cross-sectional structure in the horizontal direction of the solid material vaporizer according to the third to fifth specific examples of the present invention. That is, this figure also shows a cross-sectional structure taken along line AA ′ of FIG.
Also in the specific example shown in FIG. 4, a plurality of portions 11 </ b> R protruding toward the inside are provided on the side wall of the container 11. And the big roundness is given to the part 11P which protruded toward the outer side provided among these. By securing a large space for the portion 11P projecting outward, an effect of preventing gas retention can be expected.

Also in the specific example shown in FIG. 5, a plurality of portions 11 </ b> R protruding toward the inside are provided on the side wall of the container 11. And between these part 11R which protruded toward the inner side, the part 11P which protruded toward the rectangular outer side is provided. By making the portion 11P protruding outwards into a rectangle, the area of the side wall can be further increased, and heat introduction from an external heater can be promoted.
Also in the specific example shown in FIG. 6, a plurality of portions 11 </ b> R protruding toward the inside are provided on the side wall of the container 11. A portion 11P protruding outward is provided between the portions 11R protruding inward. And each of the part 11P which protruded toward the outer side is formed of the some small convex part 11S. If it does in this way, the area of the side wall of the container 11 can further be expanded, and the heat introduction from an external heater can further be accelerated | stimulated.
In any of the specific examples shown in FIG. 4 to FIG. 9 described above, the outer periphery of the cross section in the horizontal direction of the raw material container 11 is larger than the circumference of a circle having the same area, and thus obtained in the above-described embodiment. The same effect as the effect can be obtained.

  Moreover, since the increase amount of vaporization is proportional to the outer periphery length / bottom area of the raw material container 11, in the case of the same bottom area, vaporization amount increases, so that outer periphery length is long. Therefore, since the outer peripheral lengths of the examples given in this example are all longer than the outer peripheral lengths in the above-described embodiments, the amount of vaporization can be further increased.

  However, if the side wall of the raw material container 11 has an excessively complicated shape, the maintainability of the apparatus may be reduced. Therefore, depending on the type of the solid raw material, various shapes may be used as long as those skilled in the art can easily perform maintenance and the like.

Next, a specific example in which the arrangement and quantity of the gas inlet 12 and the gas outlet 13 are devised will be described.
7 and 8 are schematic views illustrating the cross-sectional structure in the horizontal direction of the solid material vaporizers of the sixth and seventh specific examples of the present invention. That is, these drawings show a cross-sectional structure taken along line AA ′ of FIG.
In the case of the specific example shown in FIG. 7, one gas inlet 12 is provided at the center of the raw material container 11, and the gas outlets 13 are provided at the convex portions 11 </ b> P around the raw material container 11. As described above, by providing the gas inlet 12 and the gas outlet 13 so as to be substantially symmetrical with respect to the center of the raw material container 11, the gas flows symmetrically with respect to the center of the raw material container 11. Is consumed not symmetrically from one direction but symmetrically. As a result, the vaporization rate of the solid raw material 10 is also stabilized, and the vaporized gas can be supplied stably.

Further, by providing a plurality of gas outlets 13, the conductance of the gas flow in the solid raw material 10 increases, and the vaporization efficiency increases. That is, since the heat by the heater is transmitted not only by heat conduction but also by the gas flow effect, the vaporization rate of the solid raw material 10 can be increased.
Furthermore, by providing the gas outlets 13 in each of the convex portions 11P, it is possible to suppress the retention of gas in the convex portions 11P and the disturbance of the flow.

In the case of the specific example shown in FIG. 8, one gas outlet 13 is provided in the center of the raw material container 11, and the gas inlets 12 are provided in the convex portions 11 </ b> P around the raw material container 11. When the gas inlet 12 is provided in the convex portion 11P, the introduced gas is immediately received by the heat from the heater provided outside the side wall of the container 11 and heated. That is, it is advantageous in that the heat exchange efficiency is increased. The gas introduced from the gas inlet 12 is heated by receiving heat from the heater with high efficiency on the side wall of the convex portion 11P, and the solid raw material 10 is vaporized and discharged from a gas outlet 13 provided in the center of the container. . That is, vaporization of the solid raw material can be promoted and the amount of vaporized gas discharged can be increased.
Furthermore, also in this specific example, by providing the gas introduction port 12 in each of the convex portions 11P, it is possible to suppress the stagnation of gas in the convex portions 11P, the turbulence of the flow, and the like.

The embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples.
That is, even if a person skilled in the art has changed the design of the material, structure, shape, size, and arrangement of each component constituting the solid raw material vaporizer according to the present invention, it can be used as long as it has the gist of the present invention. Are included within the scope of the present invention.

It is a mimetic diagram which illustrates the section structure of the perpendicular direction of the solid source vaporizer concerning an embodiment of the invention. It is a schematic diagram which illustrates the cross-sectional structure of the horizontal direction of the solid raw material vaporization apparatus concerning embodiment of this invention. It is a schematic diagram which illustrates the cross-section of the horizontal direction of the solid raw material vaporizer as a 2nd example of this invention. It is a schematic diagram which illustrates the cross-section of the horizontal direction of the solid raw material vaporizer as a 3rd example of this invention. It is a schematic diagram which illustrates the cross-section of the horizontal direction of the solid raw material vaporization apparatus as the 4th example of this invention. It is a schematic diagram which illustrates the cross-sectional structure of the horizontal direction of the solid raw material vaporizer as a 5th example of this invention. It is a schematic diagram which illustrates the cross-sectional structure of the horizontal direction of the solid raw material vaporizer as a 6th example of this invention. It is a schematic diagram which illustrates the cross-section of the horizontal direction of the solid raw material vaporizer as a 7th example of this invention. It is a schematic diagram which illustrates the conventional solid raw material vaporizer. In the conventional solid raw material vaporizer, it is a schematic diagram which illustrates the middle course in which a solid raw material is consumed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid raw material vaporizer 10 Solid raw material 11 Raw material container 11P Convex part 11R Concave part 12 Gas inlet 13 Gas outlet 14 Heating heater 100 Solid raw material 1000 Solid raw material vaporizer 110 Raw material container 120 Gas inlet 130 Gas outlet 140 Heating heater

Claims (5)

A raw material container for containing a solid raw material;
A gas inlet for introducing gas into the raw material container;
A gas outlet for discharging gas from the raw material container;
With
The side wall of the internal space of the raw material container has a portion protruding inward, and the solid raw material vaporizer. A raw material container for containing a solid raw material;
A gas inlet for introducing gas into the raw material container;
A gas outlet for discharging gas from the raw material container;
A heater provided around the raw material container;
With
The internal space of the raw material container has a substantially columnar shape,
The side wall of the internal space has a portion protruding inward, and the solid raw material vaporizer.   The solid raw material vaporizer according to claim 1 or 2, wherein an outer periphery of a horizontal cross section of the internal space is longer than an outer periphery of a circle having an area equal to the area of the cross section. The portion protruding toward the inside is continuous in the vertical direction of the container,
The side wall has a plurality of portions protruding toward the inside, and a portion protruding toward the outside between them,
Near the center of the upper surface of the internal space, either the gas inlet or the gas outlet is provided,
The one of the gas inlet and the gas outlet is provided toward a space formed by the portion protruding toward the outer side, according to any one of claims 1 to 3. Solid raw material vaporizer. The portion protruding toward the inside is continuous in the vertical direction of the container,
The side wall has a plurality of portions protruding toward the inside, and a portion protruding toward the outside between them,
The side wall is provided with a plurality of portions protruding toward the outside,
Near the center of the upper surface of the internal space, either the gas inlet or the gas outlet is provided,
The one of the gas inlet and the gas outlet is respectively provided toward each of the spaces formed by the plurality of portions protruding toward the outside. The solid raw material vaporizer as described in any one.

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