JPS6376864A - Vapor deposited film forming device - Google Patents

Abstract

PURPOSE:To provide a titled device which can increase the rate of evaporation per time and is capable of forming vapor-deposited films at a high speed by heating a vapor deposition material put together with a heat insulating material into a crucible by an electron beam so that the vapor-deposited film can be formed on a substrate surface. CONSTITUTION:A filament 8 projects the electron beam 7 toward the crucible 6 when the filament is energized by a power supply 3. The vapor deposition material 2 and the heat insulating material 10 in the crucible 6 are heated by the beam 7 and the temps. thereof are increased while the transfer and reception of the heat between each are executed according to the respective physical values. The heat insulating material 10 is heated to the high temp. earlier than the vapor deposition material 2 while said material absorbs the energy of the beam 7 together with the vapor deposition material, if the heat capacity of; for example, the heat insulating material 10 is smaller than the heat capacity of the vapor deposition material 2. As a result, a temp. gradient is generated between the heat insulating material 10 and the vapor deposition material 2 and the transfer of the heat from the material 10 to the material 2 arises. The material 2 is, therefore, efficiently evaporated by the low energy of the beam 7 and in addition, the growing speed of the vapor deposited film is increased to a remarkably high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vapor deposition film forming apparatus for heating a vapor deposition material with an electron beam to form a vapor deposition film on a substrate surface.

[Conventional technology]

2. Description of the Related Art In the manufacturing process of semiconductor devices, a deposition film forming apparatus is used to deposit electrode materials and the like on the surface of a substrate. When such vapor deposition film forming apparatuses are roughly classified according to the method of heating the vapor deposition material, there are those that use a resistance heating method, those that use a high frequency heating method, and those that use an electron beam heating method.

An apparatus for forming a deposited film using the resistance heating method is shown in the configuration diagram of FIG. 4, for example. A desired metal such as aluminum is placed as a vapor deposition material 2 on a boat portion of a heater 1 made of metal such as tungsten, tantalum, or molybdenum. This heater 1 is connected to a power source 3 and is energized.

When energized by the power source 3, the heater 1 generates Joule heat J,
As a result, the vapor deposition material 2 is heated by 8 tubes and its temperature rises. When the temperature of the vapor deposition material 2 exceeds a predetermined value, evaporation begins, and a vapor deposition film J is formed on the surface of a substrate (not shown).

Although a vapor deposition film forming apparatus using a high frequency heating method is not shown in the drawings, this device heats the vapor deposition material using high frequency power. Also with this method, when the temperature of the vapor deposition material reaches a predetermined value or higher, evaporation starts, and a vapor deposition film is formed on the surface of the substrate (not shown).

On the other hand, an apparatus for forming a deposited film using the electron beam heating method is shown in the configuration diagram of FIG. 5, for example. A recess is formed in the upper surface of the box 5 which functions as a cooling device, and this recess has a shape of 6. A desired metal or the like is placed in the crucible 6 as a vapor deposition material 2, and therefore the vapor deposition material 2 is cooled by cooling water 9 via the crucible 6.

Note that this cooling is performed to prevent the crucible 6 from melting and to suppress the reaction between the material of the crucible 6 (for example, copper) and the material of the vapor deposition material 2 (for example, aluminum). The filament 8 is used to generate the electron beam 7, and power is supplied to the filament 8 from the power source 3.

When power is supplied from the power source 3 to the filament 8, an electron beam 7 is generated, and the vapor deposition material 2 contained in the crucible 6 is irradiated with the electron beam 7. Then, the vapor deposition material 2 is heated by the energy of the electron beam 7, and its temperature increases. When the temperature of the vapor deposition 'vJ2 rises and exceeds a predetermined value, evaporation begins, thereby forming a vapor deposited film on the surface of a substrate (not shown).

[Problem that the invention seeks to solve]

However, these conventional devices have various problems as shown below.

First, although resistance heating can perform vapor deposition at a relatively high speed, the amount of vapor deposition per time is small. This is because the capacity of the boat to hold the vapor deposition material is small, and for this reason it is not suitable for the purpose of forming a thick vaporized film.In addition, the equipment using high frequency heating is expensive; Therefore, the loss of manufactured products (semiconductor devices, etc.) increases by 1 to 10%.

On the other hand, with electron beam heating, it is possible to increase the amount of evaporation per cycle, and therefore it is possible to form not only a relatively thin evaporated film but also a thick film with a thickness of 1μ or more. It can also be effectively applied in any case. However, with conventional vapor deposition film forming equipment using electron beam heating,
Since the vapor deposition material is cooled through the crucible, a sufficient amount of vapor cannot be evaporated per unit time, and therefore the formation rate of the vapor deposited film is slow. Furthermore, if the electron beam is made to have high energy to generate heat that exceeds cooling, droplets will come out from the evaporation material in the crucible.

Furthermore, if the deposition film is formed at a low rate, the time required for deposition becomes longer as the thickness of the film increases, resulting in an increase in the temperature of the substrate during deposition. When the temperature of the substrate rises, minute irregularities appear in the vapor deposited film formed on the substrate, causing so-called "cloudiness" and making it impossible to obtain a good film.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vapor deposited film forming apparatus that can increase the vapor deposition ω per time and form a vapor deposited film at high speed.

(Means for Solving the Problems) A vapor deposited film forming apparatus according to the present invention is an apparatus that heats a vapor deposition material contained in a crucible with an electron beam, and the crucible includes a heat insulating material mixed with the vapor deposition material. It is characterized by being contained.

(Function) Since the vapor deposition film forming apparatus according to the present invention is configured as described above, the vapor deposition material contained in the crucible and the heat insulating material mixed therein are simultaneously heated by an electron beam, and are heated according to their respective physical property values. Since it works to store heat ω and to exchange heat between them, it effectively injects the energy of the electron beam into the deposit.

〔Example〕

Hereinafter, some embodiments of the present invention will be described with reference to FIGS. 1 and 2 of the accompanying drawings. In addition, in the description of the drawings, the same elements are given the same reference numerals and redundant description will be omitted.

FIG. 1 is a block diagram of a vapor deposition film forming apparatus according to the present invention.

This is different from the conventional apparatus shown in FIG. 5 in that a heat insulating material 10 is housed in a crucible 6 having a concave cross section and mixed with the vapor deposition material 2. As the material for the crucible 6, for example, copper is used, and as the material for the heat insulating material 10, for example, a high boiling point inorganic compound such as boron nitride or a high boiling point inorganic material such as carbon is used.

Next, the operation of the apparatus of the above embodiment will be explained.

When the filament 8 is energized from the power source 3,
Filament 8 directs electron beam 7 toward crucible 6 . Here, since the heat insulating material 10 is housed in the crucible 6 mixed with the vapor deposition material 2, the vapor deposition material 2 and the heat insulating material 10 are heated by the electron beam 7, and their respective physical properties (for example, specific heat value, heat (conductivity value, etc.), the temperature rises while transferring heat to and from each other.

At this time, for example, if the heat capacity of the heat insulating material 10 is smaller than that of the vapor deposition material 2, the heat insulating material 10 absorbs the energy of the electron beam 7 together with the vapor deposition material 2, and is heated to a high temperature faster than the vapor deposition material 2.

As a result, a temperature gradient occurs between the heat insulating material 10 and the vapor deposition material 2, and heat is transferred from the heat insulating material 10 to the vapor deposition material 2. That is, in the above case, the insulation II 10 acts as an effective heat collector.

Next, for example, if the thermal conductivity value of the heat insulating material 10 is larger than that of the vapor deposition material 2, the heat insulating material 10 absorbs the energy of the electron beam 7 together with the vapor deposition material 2, and the temperature rises, and the crucible is heated. The energy of the electron beam 7 that is irradiated with a partial intensity variation within the electron beam 6 is flattened in the form of thermal conductivity.

That is, in the above case, the heat insulating material 10 has the effect of dispersing the energy of the electron beam 7 all around the vapor deposition material 2 and injecting it into the vapor deposition material 2, thereby making the heating uniform.

Note that since the material of the heat insulating material 10 can be selected to have a boiling point higher than that of the vapor deposition material 2, contamination by the heat insulating material 10 will not occur when the vapor deposition material 2 is heated to form a vapor deposited film thereof. -Also, in the explanation of the effects of the above embodiments, two different effects were described as being independent, but in reality they often act in combination. The degree of these combinations can be adjusted to suit the purpose by appropriately setting the difference in physical property values between the vapor deposition material 2 and the heat insulating material 10.

As a result, not only can the deposition material 2 be efficiently evaporated with low energy of the electron beam, but also the growth rate of the deposited film can be dramatically increased. Furthermore, since the energy of the electron beam is dispersed by the heat insulating material 10 and injected into the evaporation material 2, even if the heating power of the electron beam is increased, the evaporation material 2 will not be scattered as in the prior art. Never. In addition, by forming a film in a short time using high-speed evaporation, it is possible to suppress the rise in substrate temperature during evaporation using an electron beam, so that the substrate does not become cloudy.
will not occur.

At the same time, since the crucible 6 can contain a relatively large amount of vapor deposition material 2 mixed with the heat insulating material 10, it is possible to increase the amount of vapor deposition per one time, and therefore, it is possible to increase the amount of vapor deposition per time. can be obtained quickly.

FIG. 2 is a perspective view with a part of the crucible 6 cut away to show some examples of the heat insulating material 10 according to the present invention. In the example shown in FIG. Even when the vapor deposition material 2 melts and the heat insulating material 10a floats in the recessed part 6, the heat insulating material 1 occupies the liquid surface.
The area of 0a can be minimized. As a result, since the area occupied by the vapor deposition material 2 on the liquid surface can be increased, the effective evaporation area of the vapor deposition material 2 from the liquid surface can be increased, and therefore the film growth rate can be increased by one. In addition, the heat insulating material 10a
By making it spherical, the area in which the heat insulating material 10a contacts the inner wall of the crucible 6 can be made small, and the heat loss escaping from the heat insulating material 10a to the crucible 6 can be reduced. Furthermore, since the heat insulating material 10a is covered with a curved surface, it has special effects such as not interfering with the flow of the vapor deposition material 2 within the crucible 6.

In the example shown in FIG. 2(b), the heat insulating material 10b has a hexahedral shape. Therefore, manufacturing is easy, and the position of the heat insulating material 10b in the crucible 6 can be stably set. Note that the portion of the heat insulating material 10b that contacts the inner wall of the crucible 6 may be shaped into an arc to match the curvature of the crucible 6.

Although only one heat insulating material 10a is shown in the examples of FIGS. 2(a) and 2(b), a plurality of heat insulating materials 10a may be placed in the crucible 6.

Further, the shape of the heat insulating material 10 is not limited to that shown in FIG. 2, and may be, for example, tetrahedral or pellet-shaped. Further, the material of the heat insulating material 10a, 'Job is not limited to boron nitride, but may also be a high boiling point inorganic compound such as aluminum oxide, silicon nitride, silicon carbide, or a high boiling point inorganic material such as carbon, tungsten, tantalum, molybdenum, or platinum. Can be used.

Although not shown in the figure, a heat insulating member is placed inside the recess of the crucible 6, the inner surface of the heat insulating member is formed into a recess, and the heat insulating material 10 mixed with the vapor deposition material 2 is housed in the inner recess of the heat insulating member. You can also. According to this, since the vapor deposition material 2 and the heat insulating material 10 do not directly contact the crucible 6, heat loss due to water cooling of the crucible 6 is reduced, and therefore heating of the vapor deposition material 2 and the heat insulating material 10 by the electron beam is effective. This can be done in a specific manner.

In order to confirm the effects of the present invention explained above, the present inventors
The following experiment was conducted. First, use boron nitride to
A heat insulating material having the shape shown in Figure (a) was manufactured. Here, the diameter of the insulation material is 5mm, the inner diameter of the crucible is 25m, and the depth is 1mm.
It was set to 0m. Aluminum was used as the vapor deposition material, and 1 CC of granular aluminum with several layers in diameter was placed in a crucible together with a heat insulating material. Then, an electron beam was irradiated with a power of 3 KW, and aluminum was vapor-deposited on the silicon substrate at a distance of 20 cm.

As a result, an aluminum film with a thickness of 10 μm could be formed on the surface of the silicon substrate at a rate of 3 μTrL/min.

Furthermore, the present inventor has developed an aluminum 1 cum film forming apparatus using a conventional resistance heating method shown in FIG. 4 and a conventional electron beam heating method using no heat insulating material shown in FIG. A formation experiment was conducted and the results were compared with those obtained by a vapor deposition film forming apparatus using the heat insulating material according to the present invention.

An example of the above comparison results is shown in FIG. As is clear from the figure, by mixing the heat insulating material with the vapor deposition material as in the present invention, it is possible to increase the vapor deposition rate while increasing the amount of vapor 1 per vapor deposition. In addition, in the film formed by the electron beam heating method without using a heat insulating material according to the conventional technology, cloudiness appears on the surface of the film. This is considered to be because the substrate was heated to 200'C to 250'C during the long-time vapor deposition, which caused part of the aluminum film to crystallize. Since the film formed according to the present invention has a much faster growth rate, a thick film can be obtained by vapor deposition in a short time.

As a result, the radiant heat that the substrate receives from the crucible is drastically reduced, and the aluminum film does not crystallize, making it possible to form an excellent vapor deposition material without clouding.

(Effects of the Invention) As described in detail above, according to the present invention, since the crucible contains the moisturizing material mixed with the vapor deposition material,
It is possible to evaporate a relatively large amount of evaporated material contained in the crucible, and therefore the amount of evaporation m per time can be increased. Furthermore, since the energy of the electron beam is effectively injected into the vapor deposition material through the heat insulating material, there is an effect that vapor deposition can be performed at high speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a vapor deposition film forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective sectional view of several examples of heat insulating materials used in the apparatus of the present invention, and FIG. 3 is a diagram of a conventional apparatus and FIG. 4 is a diagram showing the experimental results using the apparatus of the present invention, FIG. 4 is a configuration diagram of a conventional apparatus using a resistance heating method, and FIG. 5 is a configuration diagram of a conventional apparatus using an electron beam heating method. 1... Heater, 2... Vapor deposition material, 3... Power supply, 6...
... Crucible, 7... Electron beam, 8... Filament, 10, 108.10b-... Heat insulating material. Patent Applicant Sumitomo Electric Industries Co., Ltd. Patent Attorney Yoshi Hase Printing Configuration diagram of the device of the present invention Figure 1 (a) (b) 10b Perspective view side 2 Figure 3 of the heat insulating member according to the present invention

Claims (1)

[Claims] 1. In a vapor deposition film forming apparatus that heats a vapor deposition material contained in a crucible with an electron beam to form a vapor deposition film on a substrate surface, the crucible contains a heat insulating material mixed with the vapor deposition material. A vapor deposition film forming apparatus characterized in that: 2. The vapor deposited film forming apparatus according to claim 1, wherein the boiling point of the heat insulating material is higher than the boiling point of the vapor deposition material. 3. The vapor deposited film forming apparatus according to claim 1, wherein the heat capacity of the heat insulating material is smaller than the heat capacity of the mixed vapor deposition material. 4. The heat insulating material is made of a high boiling point inorganic material such as carbon, tungsten, tantalum, molybdenum, platinum, or a high boiling point inorganic compound such as boron nitride, aluminum oxide, silicon nitride, silicon carbide, etc. The vapor deposition film forming apparatus described above.