JPH0466662A - Vacuum vapor deposition apparatus - Google Patents

Abstract

PURPOSE:To surely and continuously recover a vapor deposited material stuck to a vapor recovering plate under liquefying, to enable continuous operation for long time and to provide a vacuum vapor depositing apparatus economically profitable by dividing the vapor recovering plate into plural zones and periodically varying temp. distribution at each zone. CONSTITUTION:Metal vapor 10 vaporized toward a different direction from a substrate in a vacuum vessel of the vacuum vapor depositing apparatus, is stuck to the vapor recovering plate 21 and the formed vapor deposited film 13 is heated, melted and recovered. The above vapor recovering plate 21 set symmetrically to right and left directions inclined from a upper part to a diagonal lower part of the substrate is divided into plural small area zones 22 toward a direction with a right angle to the inclining surface. In each zone 22, a heater is independently set and electric source output is periodically varied with control means so as to be possible to control at different temp. By periodically varying the temp. of heater according to recovering time, the temp. distribution in each zone 22 is varied to high temp. low temp. intermediate temp. high temp. Therefore, as the melting zone in the vapor deposited film 13 is shifted to the inclining direction in order, the vapor deposited film 13 stuck to the vapor recovering plate 21 can surely be recovered without detaching and falling down.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention is a vacuum evaporation apparatus using an electron beam heating method, in particular, which continuously collects evaporation substances adhering to surfaces other than the substrate and performs evaporation again. The present invention relates to a vacuum evaporation apparatus that can be used to improve the operating efficiency and economic efficiency of the apparatus.

(Prior Art) Conventionally, for example, in the development of semiconductor film forming processing, a thin film forming technique using vacuum evaporation has been adopted for boat fishing.

This thin film production technology vaporizes the deposition material in vacuum and deposits it on the substrate, and as a means for vaporizing the material, electron beams are particularly advantageous due to their technical simplicity and economical aspects in terms of generation and control. It is widely used because of this.

FIG. 5 schematically shows an example of a schematic configuration of a vacuum evaporation apparatus using such an electron beam heating method.

In FIG. 5, the vacuum chamber 1 is maintained at a predetermined degree of vacuum (10-' to 10-6 Torr) by an evacuation device (not shown).
is maintained. Inside the vacuum chamber 1, a steam enclosure 2 having a circumferential wall surface that is inclined to narrow from the top to the bottom is provided, and a crucible 4 containing a vapor deposition substance 3 is installed at the bottom of the vapor enclosure 2. A substrate 5 to be vapor-deposited is provided above it and supported by a support (not shown). Further, an electron gun 6 is disposed on one side of the crucible 4, and the vapor deposition material 3 is heated and evaporated by irradiating the vapor deposition material 3 with an electron beam 7 emitted from the electron gun 6 (electronic impact). to generate a steam stream 8. in this case,
A cooling vibrator 9 is embedded in the crucible 4 to prevent the crucible 4 through which cooling water is flowed during heating from becoming too high and melting.

Further, above the substrate 5, two vapor recovery plates 11 for recovering vapor flow 10 that evaporates in a direction different from that of the substrate 5 are arranged symmetrically so as to be inclined obliquely downward from the upper part of the substrate 5. and is supported by a support member (not shown).

Therefore, in a vacuum evaporation apparatus with such a configuration,
When the vapor deposition material 3 housed in the crucible 4 is irradiated with an electron beam 7 from an electron gun 6 to heat and evaporate the vapor deposition material 3, a vapor flow is generated and diffused, and a vapor flow 8 rises toward the substrate.
When collides with the substrate 5, a vapor deposited film 12 is formed on the substrate 5, and the vapor flow 1 evaporates in a direction different from the direction of the substrate 5.
0 collides with the vapor recovery plate 11, a vapor deposited film 13 is formed on the recovery plate 11. The vapor deposited film 13 formed on the vapor recovery plate 11 is melted and liquefied by uniformly heating the entire recovery plate 11 with a heat source (not shown) at a temperature higher than the melting point of the vapor deposition material. The liquid flows down along the slope of the lower surface of the steam container 2, and is collected into the crucible 4 along the wall surface of the steam enclosure container 2.

(Problem to be Solved by the Invention) However, in such a conventional vacuum evaporation apparatus, when the entire vapor recovery plate 11 is heated uniformly to melt the vapor deposited film 13, the vapor recovery plate 11 and the vapor deposition film 13 are first heated. Since the contact portion with the vapor-deposited film 13 melts, the vapor-deposited film peels off due to its own weight and falls, and cannot be properly collected into the crucible. In addition, even if the vapor deposited film does not peel off, if the surface tension and specific gravity of the vapor deposited substance are high or the wettability with the recovery plate is low, droplets due to melting of the substance adhered to the recovery plate may fall onto the slope of the vapor recovery plate. The droplets grow as they flow down, and if they exceed the falling weight limit, they will drop from the vapor recovery plate, making it impossible to continuously liquefy and recover the vapor, which poses a problem in that the device cannot be operated continuously for long periods of time.

SUMMARY OF THE INVENTION An object of the present invention is to provide an economically advantageous vacuum evaporation apparatus that can reliably and continuously liquefy and recover evaporated substances adhering to a vapor recovery plate, thereby enabling continuous operation for a long period of time.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the first invention, a crucible containing a vapor deposition material is disposed in a vacuum chamber, and the vapor deposition material is melted by irradiation with an electron beam. is heated and evaporated, and the metal vapor is deposited on a substrate provided above the crucible to form a vapor deposited film, and the metal vapor is deposited on a vapor recovery plate provided at a position different from the substrate in a direction different from the direction of the substrate. In a vacuum evaporation apparatus that deposits metal vapor to be evaporated on the surface and recovers the vaporized material by heating and melting the vapor, the vapor recovery plate is divided into a plurality of regions and each region is heated to a different temperature. A control means is provided for controlling the heating means and periodically changing the temperature distribution in each region.

Further, in the second invention, a crucible containing a vapor deposition material is disposed in a vacuum chamber, the vapor deposition material is heated and evaporated by irradiation with an electron beam, and the metal vapor is deposited on a substrate provided above the crucible. metal vapor that evaporates in a direction different from the direction of the substrate is deposited on a vapor recovery plate provided at a position different from the substrate, and this vapor deposition material is heated, melted, and recovered. In such a vacuum evaporation apparatus, the vapor recovery plate is arranged to face the lower surface of the vapor recovery plate at an appropriate distance, and the droplets formed by melting the vapor deposition material on the vapor recovery plate have a droplet diameter that is larger than the droplet diameter when the droplet weight is the falling limit weight. A mesh body having meshes with small intervals is provided.

(Function) In the vacuum evaporation apparatus according to the first invention, the regions divided by the vapor recovery plate are, for example, a high temperature region (temperature region above the melting point of the evaporation material and below the boiling point), a medium humidity region (a region with a temperature above the melting point of the evaporation material and below the boiling point of the evaporation material), Temperature range, for example, about 10 to 20 degrees lower than the melting point)
, low temperature region (e.g. 30 to 50 d below the melting point of the vapor deposition material)
By periodically controlling the heating means of each region as a low temperature region (e.g. low temperature region), even if only the deposited film in the high temperature region liquefies, the deposited film in other regions does not liquefy. This eliminates the possibility of the vapor separating from the vapor recovery plate and falling, allowing continuous liquefaction recovery.

In addition, in the vacuum evaporation apparatus according to the second aspect of the invention, even if a droplet generated by melting the vapor deposition material on the vapor recovery plate becomes larger than the falling limit weight and drops from the vapor recovery plate, the liquid droplet will not fall below the vapor recovery plate. Since the distance between the meshes of the mesh provided in the mesh is smaller than the droplet diameter, the droplets move along the slope of the mesh, making continuous liquefaction recovery possible.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing only the main part of the first embodiment of the present invention, that is, a steam recovery plate, and FIG. 2 is a sectional view taken along the line 1--2 in FIG. Note that the other configuration of the vacuum evaporation apparatus is the same as that shown in FIG. 5, so the explanation thereof will be omitted here.

In the first embodiment, a plurality of small-area regions 22 are formed as a vapor recovery plate 21 in a direction perpendicular to the inclined surface, which is arranged symmetrically and inclined diagonally downward from above the substrate 5 in FIG. Each region 22 is provided with an independent heater (not shown) for heating the region. Furthermore, each independent heater can be controlled to different temperatures by periodically changing the power output by a control means (not shown).

In the steam recovery plate 21 having such a configuration, the temperature control conditions of the heaters in each area are set, for example, the high temperature area part 22a.
The temperature distribution is above the melting point and below the boiling point of the vapor deposition material, and the medium temperature region 22b is slightly lower than the melting point of the vapor deposition material, for example 10 to 2
When the heaters in each region are controlled by the control means so that the temperature distribution is about 0 degrees lower, and the temperature distribution in the low temperature region 22c is lower than the melting point of the vapor deposition material, for example, about 30 to 50 degrees, the vapor deposited film attached to the high temperature region 22a is It melts and liquefies and flows down the slope. In this case, the high temperature region 22a has a small elongated area divided in a direction perpendicular to the inclination direction, and the amount of vapor deposition in this region is small.
There is no possibility that the vapor-deposited film will peel off from the vapor recovery plate 21 due to its own weight and fall into the crucible, thereby disturbing the vapor-deposition state.

By changing the high temperature region 22a, medium temperature region 22b, and low temperature region 22c at a cycle according to the recovery time, the temperature distribution in each region changes from high temperature to low temperature to medium temperature to high temperature. Therefore, since the melted region of the vapor deposited film sequentially moves in the oblique direction, the vapor deposited film attached to the vapor recovery plate 21 can be reliably recovered without peeling off and falling.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a perspective view showing the main part, that is, the steam recovery section, in the second embodiment of the present invention, and FIG. 4 is a perspective view showing the I of FIG.
It is a partially enlarged view taken in section along the V-IV line. In addition,
The other configuration of the vacuum evaporation apparatus is the same as that shown in Fig. 5, so
The explanation thereof will be omitted here. In the second embodiment, a material is made of a material that is difficult to get wet with droplets of vapor deposition material or is made to face the lower surface of a vapor recovery plate 31 that is arranged symmetrically and inclined diagonally downward from above the substrate 5 in FIG. A mesh body 32 formed on the surface is provided.

In this case, the meshes 11 of the mesh body 32 are arranged at intervals smaller than the droplet diameter dcrtt when the droplets generated by melting the vapor-deposited substance on the vapor recovery plate 31 grow and reach the falling limit weight, and the The distance between the opposite sides of the collection plate 31 is equal to or larger than the droplet diameter dcrit. The reason for doing this is as follows.

(1) If the facing distance between the net body 32 and the vapor recovery plate 31 is smaller than the droplet diameter d crit, the droplets attached to the vapor recovery plate 31 will grow as they flow down along the inclined surface. In some cases, it touches the net 32 before it grows to d crit and becomes trapped between the net 32 and the steam recovery plate 31. In this case, depending on the conditions, the droplets may become stuck and become clogged, making it impossible to continuously collect the deposited material.

(2) Furthermore, if the facing distance between the mesh body 32 and the vapor recovery plate 31 is too large, the droplets will grow and leave the vapor recovery plate 31 beyond d crit. The velocity upon reaching the net becomes too high, and the droplets scatter when they fall onto the net, making it impossible to continuously collect the deposited material.

For the reasons (1) and (2) above, the facing distance between the net body 32 and the vapor recovery plate 31 is determined as d crit<L<3
If the spacing between the meshes of the mesh body 32 is set to about 1.5 mm, no clogging will occur, and even if droplets of the vapor deposition material adhering to the vapor recovery plate 31 fall onto the mesh body 32, the distance between the meshes of the mesh body 32 will be 1.
By setting d crit to be smaller than d crit , the droplet does not fall downward from the net body 32 due to the surface tension of the droplet.

By providing the mesh body 32 having such a configuration so as to face the lower surface of the steam recovery plate, the following effects can be obtained.

That is, when the metal vapor rises in a direction different from the direction of the substrate, the metal vapor passes through the mesh of the net member 32 and adheres to the lower surface of the vapor recovery plate 31, and the attached substance is heated by a heating means (not shown) to become a liquid. state. As this liquid flows down along the slope of the vapor recovery plate 31, it becomes a droplet 33 and grows, and eventually the droplet 33 reaches the falling limit weight we.
When it becomes larger than rlt, it leaves the lower surface of the steam recovery plate 31 and falls onto the net body 32. However, the mesh spacing of this mesh body 32 is 1. is smaller than the droplet diameter d crtt when falling, so the surface tension of the droplet 33 causes the net 3
It will not fall downward from 2. Furthermore, since the contact area between the droplets 33 and the net 32 is small, and the net itself has low wettability with the droplets, the droplets 33 slide on the net 32 along its slope. , the deposited material can be rapidly and continuously recovered.

In each of the above embodiments, a case has been described in which the vapor deposition material adhering to the vapor recovery plate is collected into a crucible, but droplets flowing down along the slope of the vapor recovery plate are collected in a separately installed vapor recovery device. It may be collected.

[Effects of the Invention] As described above, according to the present invention, the vapor deposition material attached to the vapor recovery plate can be reliably and continuously liquefied and recovered and used for vapor deposition again, so that long-term continuous operation of the apparatus is possible. This makes it possible to provide an economically advantageous vacuum evaporation apparatus.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a vapor recovery plate in a first embodiment of the vacuum evaporation apparatus according to the present invention, and FIG. 2 is a perspective view of the vapor recovery plate shown in FIG.
3 is a perspective view showing a steam recovery section in the second embodiment of the present invention, and FIG. 4 is a sectional view taken along the line shown in FIG.
FIG. 5 is a partially enlarged cross-sectional view taken along line -IV, and is a schematic configuration diagram schematically showing an example of a conventional vacuum evaporation apparatus. DESCRIPTION OF SYMBOLS 1... Vacuum chamber, 2... Steam enclosure, 3... Vapor deposition substance, 4... Crucible, 5... Substrate, 6... Electron gun,
7...Electron beam, 8.10...Vapor flow, 21.3
1... Steam recovery plate, 32... Net body. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) A crucible containing a vapor deposition substance is placed in a vacuum chamber,
heating and evaporating the vapor deposition material by irradiation with an electron beam, and depositing the metal vapor on a substrate provided above the crucible to form a vapor deposition film; and a vapor recovery plate provided at a position different from the substrate. In a vacuum evaporation apparatus, the vapor recovery plate is divided into a plurality of regions, and the vapor recovery plate is divided into a plurality of regions. A vacuum evaporation apparatus characterized in that a heating means for heating regions to different temperatures is provided, and a control means is provided for controlling the heating means to periodically change the temperature distribution of each region. (2) A crucible containing a vapor deposition substance is placed in a vacuum chamber,
heating and evaporating the vapor deposition material by irradiation with an electron beam, and depositing the metal vapor on a substrate provided above the crucible to form a vapor deposition film; and a vapor recovery plate provided at a position different from the substrate. In a vacuum evaporation apparatus in which a metal vapor is deposited on a metal vapor that evaporates in a direction different from the direction of the substrate, and the vapor-deposited material is heated, melted, and recovered, an appropriate distance is provided on the lower surface of the vapor recovery plate. 1. A vacuum evaporation apparatus, characterized in that a net body is provided facing the vapor recovery plate and having a mesh having a smaller interval than the droplet diameter when the droplet generated by melting the vapor deposition substance on the vapor recovery plate has a fall limit weight.