JPS6369967A - Deposited film forming device - Google Patents

Abstract

PURPOSE:To provide a deposited film forming device which can suppress the heat loss from a vapor deposition material, by interposing a heat insulating member between a vapor deposition material and the inside surface of a crucible contg. said material. CONSTITUTION:An electron beam 7 generated when a filament 8 is energized by a power supply 3 is projected to the vapor deposition material 2 and the heat generated by the material 2 is transferred to the heat insulating member 10 to increase the temp. of the material 2 and the member 10. Since the heat transfer between the member 10 and the crucible 6 is small, the heat loss can be kept low; therefore, the material 2 can be efficiently heated by the beam 7. As a result, the formation of the vapor deposited film on the substrate surface is executable at a high speed. Since the member 10 can house a relatively large amt. of the material 2, the vapor deposition amt. per time is increased.

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 heat due to Joule heat, thereby heating the vapor deposition material 2 and increasing its temperature. When the temperature of the vapor deposition material 2 exceeds a predetermined value, evaporation begins, thereby forming a vapor deposition film 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 forms a crucible 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 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 material 2 rises and exceeds a predetermined value, evaporation begins, thereby forming a vapor deposition film on the surface of a substrate (not shown).

(Problems to be Solved by the Invention) 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 due to the small capacity of the boat to accommodate the deposition material, which makes it impractical for thick film formation.

Furthermore, the equipment using high-frequency heating is expensive, leading to an increase in the cost of manufactured products (semiconductor devices, etc.).

On the other hand, electron beam heating can increase the amount of vapor deposition per one time, and therefore can be effectively applied not only to the formation of thin films but also to the formation of thick films. However, in the conventional vapor deposition film forming apparatus using electron beam heating, the vapor deposition material is cooled through a crucible, so a sufficient amount of vapor cannot be evaporated per unit time, and therefore the formation rate of the vapor deposition 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 rate is low, the time required for deposition increases 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 amount of vapor per vapor deposition and form a vapor deposited film at high speed.

[Means for Solving the Problems] The 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 must include a heat insulating member between the inner surface of the crucible and the vapor deposition material. It is characterized in that it is provided in an interposed manner.

[Effect]

Since the vapor deposition film forming apparatus according to the present invention is constructed as described above, the heat insulating member functions to contain a relatively large amount of vapor deposition material therein, and prevents heat from the vapor deposition material from being transmitted to the crucible. work to prevent it.

〔Example〕

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

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

The difference from the conventional apparatus shown in FIG. 4 is that a heat insulating member 10 is fitted into a crucible 6 having a concave cross section, and the vapor deposition material 2 is contained therein. For example, copper is used as the material for the crucible 6, and boron nitride is used as the material for the heat insulating member 10, for example.

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

When the filament 8 is energized from the power source 3, an electron beam 7 is generated, and the vapor deposition material 2 is irradiated with the electron beam 7. For this reason, the vapor deposition material 2 generates heat due to the energy of the electron beam 7, and this heat is transmitted to the heat insulating member 10, so that the temperatures of both the vapor deposition material 2 and the heat insulating member 10 rise. However, since the heat conduction between the heat insulating member 10 and the crucible 6 is small, the heat loss can be suppressed to a low level, and therefore the vapor deposition material 2 is efficiently heated by the electron beam 7. As a result, the vapor deposition material 2
can be efficiently evaporated, so that a deposited film can be formed on the surface of a substrate (not shown) at high speed.

At the same time, since the heat insulating member 10 fitted in the crucible 6 can contain a relatively large amount of the vapor deposition material 2, the amount of vapor deposition per time can be increased. Therefore, not only one film but also a thick film can be formed at high speed.

FIG. 2 is a perspective view showing some examples of heat retaining members according to the present invention. If the heat insulating member 10 is constructed as a housing structure as shown in FIG. As shown in FIG. 2B, by providing a protrusion 10a protruding from the bottom surface inside the casing, the uniformity of the temperature distribution of the vapor deposition material 2 can be improved. Therefore, it is possible to further reduce heat loss and increase the deposition rate. By forming a plurality of protrusions 10b as shown in FIG. 3C, the uniformity of temperature distribution can be further improved. Further, as shown in FIG. 2D, a flat plate-shaped protrusion 10G may be formed from the side surface of the cylindrical body forming the heat insulating member 10.

The shape of the heat insulating member 10 is not limited to that shown in FIG. 2, and may be configured as a rectangular housing, for example. In addition, heat insulation member 1
The material of 0 is not limited to boron nitride, but also alumina,
Various materials such as silicon nitride, carbon, silicon carbide, tantalum, molybdenum, and platinum can be used.

In order to confirm the effects of the present invention explained above, the present inventors
The following experiment was conducted. First, a heat insulating member having the shape shown in FIG. 2(b) was manufactured using Volonty 1 to Ride.

Here, the outer diameter of the heat insulating member is 24.51rIMφ, the height is 10m, and the outer diameter of the central protrusion is 10IrIIriφ.
, the height was closed at 10#. In addition, this heat insulating member has an inner diameter of 2
The crucible was fitted into a crucible having a diameter of 5 mm and a depth of 10 m, and contained 1 cc (2.7 Y) of aluminum as a vapor deposition material. Then, an electron beam is irradiated with the energy of 3 films w, and 20
Aluminum was deposited on a silicon substrate at a distance of cm.

As a result, a 10 μm thick vapor deposition film was formed on the surface of the silicon substrate at a rate of 2.5 μm/min.

Further, the inventor conducted an experiment similar to the above using a heat insulating member having the shape shown in FIG. 2(a).

However, the outer diameter of the heat insulating member, the energy of the electron beam, etc. were the same as in the above experiment.

Furthermore, the present inventor conducted an experiment using a vapor deposition film forming apparatus using the conventional resistance heating method shown in FIG. 4, and a similar vapor deposition film forming apparatus using the conventional electron beam heating method shown in FIG. We conducted an experiment.

The results of the above four experiments are shown in FIG. As is clear from the figure, if a heat retaining member is used, the deposition rate can be increased while increasing the amount of deposition m, and if a heat retaining member with a protrusion is used, the deposition rate can be further increased. Note that when using a heat insulating member without protrusions (as shown in FIG. 2 (a)), clouding appeared on the surface of the deposited film;
This is considered to be because the aluminum crystallized due to the high temperature of the substrate. That is, by using a heat insulating member with protrusions, the deposition time can be shortened, and the temperature of the substrate surface can be kept below 100° C., so that no clouding occurs. However, if a heat insulating member without protrusions is used, the deposition time becomes longer, and the temperature of the substrate surface increases from 200'C to 250'C.
℃, aluminum crystallizes.

Therefore, it can be seen that the one using a heat insulating member without a protrusion is particularly suitable for forming a thin film at high speed, and the one using a heat insulating member with a protrusion is particularly suitable for forming a thick film.

〔Effect of the invention〕

As described above in detail, according to the present invention, since the heat insulating member is interposed between the inner surface of the crucible and the vapor deposition material,
A relatively large amount of vapor deposition material can be contained in the heat insulating member, and heat loss from the vapor deposition material can be suppressed, so
This has the effect of increasing the amount of vapor deposition per one time and allowing high-speed vapor deposition.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a vapor deposited film forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of several examples of heat insulating members used in the apparatus of the present invention, and FIG. 3 is a conventional apparatus and the present invention. FIG. 4 is a block diagram of a conventional device using a resistance heating method, and FIG. 5 is a block diagram of a conventional device using an electron beam heating method. 1... Heater, 2... Vapor deposition material, 3... Power supply, 6...
... Crucible, 7... Electron beam, 8... Filament, 10... Heat retention member, 108-10G... Projection. 1.0a (a) (b) Perspective view of the heat retaining member according to the present invention.FIG. 2

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, a heat insulating member is interposed between the inner surface of the crucible and the vapor deposition material. A vapor deposition film forming apparatus characterized in that it is provided with 2. The vapor deposited film forming apparatus according to claim 1, wherein the heat insulating member is a casing fitted into the crucible, and the vapor deposition material is contained in the casing. 3. The vapor deposition film forming apparatus according to claim 2, wherein one or more protrusions are formed on the inner surface of the casing. 4. The vapor deposited film forming apparatus according to claim 1, wherein the heat insulating member is provided in the crucible so as to be freely inserted into and removed from the crucible.