JPH0730441B2 - Coil for vapor deposition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition coil used as an evaporation source heater during vapor deposition.

[0002]

2. Description of the Related Art Generally, a vapor deposition coil of this type is used for vapor deposition of aluminum, for example, in manufacturing a semiconductor device. In this case, the evaporation coil is used as an evaporation source heater for evaporating aluminum disposed inside the coil, and the material of the coil itself is formed of a heat-resistant metal such as tungsten, molybdenum, or tantalum. . In the vapor deposition method,
When vapor deposition is performed using the vapor deposition coil described above, the coil is energized to heat and vaporize the vapor deposition material loaded in the coil.

However, when the amount of aluminum is large, the contact time with the hot water is long and the corrosion is correspondingly large, and the conventional vapor deposition coil can withstand repeated use of 0.5 g or more at one time. It was limited to 3 to 4 times. Also, when the coil is heated to a high temperature and used for a long time, the coil sags, and the sag does not return even after cooling the coil, and the sagging further increases due to repeated use. there were.

If the amount of sagging is too large, the evaporation becomes non-uniform, and therefore the vapor deposition on the object to be vapor-deposited becomes non-uniform, so that it becomes unusable. Further, when the coil is deformed, it becomes difficult to load the evaporation material. From this point as well, there is a strong demand for a coil with as little sag as possible.

From the above points, it has been attempted to add various additives to the heat-resistant alloy to reduce the sagging of the coil for the vapor deposition coil, and Japanese Patent Publication No. 54-15257.
By coarsening the crystal grains as shown in, it is recognized that the repeated use can be extended to a minimum of 5 times, a maximum of 18 times, and an average of 11 times.

[0006]

There are two types of conventional vapor deposition coils, one having a straight rod shape using a stranded wire (shown in FIG. 3) and the other having a coil shape. In the latter coil-shaped vapor deposition coil, the coil shape includes a horizontal coil shape (shown in FIG. 4), a basket type (shown in FIG. 5), and a hanging type (shown in FIGS. 6 and 7). A single wire or a stranded wire is generally used. The amount of aluminum that can be vapor-deposited using these vapor-deposition coils is 0.1 to 0.3 (g / g).
Times) and an extremely small amount. Therefore, it is necessary to deposit a relatively large amount of aluminum of about 2 to 5 (g / cycle) with one deposition of these vapor deposition coils, for example, a vapor-deposited aluminum vapor-deposited plastic for a magnetic shield used in a computer or the like. It cannot be applied to shielding plates. This also applies to the vapor deposition coil disclosed in Japanese Patent Publication No. 54-15257. That is, conventionally, no consideration has been given to a vapor deposition coil capable of vapor depositing a large amount of aluminum.

According to the consideration of the inventors, the following phenomenon was observed in the above-mentioned vapor deposition coil. That is, in a vacuum vapor deposition furnace, 2 to 5 aluminum is placed in the tungsten coil.
(G / time) When loaded and energized to start aluminum vapor deposition,
First, the tungsten coil begins to generate heat, then the aluminum melts, and then the aluminum spreads by capillary action throughout the coil and becomes vapor to evaporate.

In this case, in any of the shapes shown in FIGS. 3 to 7, if the amount of molten aluminum increases, the molten aluminum drops from the gaps between the coils and a predetermined amount of vapor deposition cannot be obtained. On the contrary, when the coil pitch gap of the coils having the shapes shown in FIGS. 4 to 7 is reduced, the pitch gap is filled with the molten aluminum, the resistance is lowered, the temperature is lowered, and the aluminum is not evaporated. Therefore, the amount of aluminum vapor deposited once is 0.1 to 0.3 (g
/ Times) and can be used only within that range. Even with a straight rod-shaped vapor deposition coil, the amount of drop is large and the desired amount of evaporation cannot be obtained as in the above case.

It was also found that the bottom of the coil was gradually corroded and thinned every time vapor deposition was repeated. When this phenomenon occurs, the aluminum melt runs out,
It was also found that the current density at the bottom of the coil rises and the temperature of the coil rises abnormally, eventually leading to wire breakage.

An object of the present invention is to provide a vapor deposition coil capable of mitigating corrosion of the coil bottom portion and preventing abnormal heat generation, prolonging the life for repeated use and evaporating more aluminum in a single vapor deposition. It is to be.

[0011]

According to the present invention, two coil end portions are defined on both sides and end regions respectively surrounded by the coil end portions are provided, and between the two coil end portions. In a vapor deposition coil having a heat resistant metal coil part wound inwardly to surround a space and a foot end part drawn out from each of the end parts, one of the foot end parts is the one end part. A vapor deposition coil is obtained which extends across the region and has a mounting coil attached to at least one of the foot end portions.

Furthermore, according to the present invention, the wire diameter of the mounting coil is 0.5 mm to 2.0 mm, the length in the mounting direction of the coil is greater than or equal to the outer diameter of the vapor deposition coil, and 50
A vapor deposition coil is obtained which is characterized by being less than or equal to mm.

[0013]

Embodiments of the present invention will be described with reference to FIG.

The vapor deposition coil 1 as shown in FIG.
Two ring-shaped coil end portions 4, 4'on both sides thereof,
A coil portion 3 made of a heat-resistant metal and wound between the coil end portions 4 and 4 ′ so as to surround a space inside, and the coil end portions 4 and 4.
4 ', each of which is made up of foot ends 2, 2'. Further, the foot end portion 2 is attached to the upper clamp portion (not shown) and the foot end portion 2'is attached to the lower clamp portion (not shown) so that the coil 1 is set vertically. Further, a separately prepared mounting coil 5 is mounted on the foot end portion 2 '. As shown in FIG. 1 (b), the foot end portion 2 ′ of the coil portion 3 extends across the bottom region of the coil portion 3, and the mounting coil 4 extends across the bottom region of the coil portion 3. It is attached to the foot end 2 '.

If the coil pitch is too large, the molten aluminum will spill, and if it is too small, the molten aluminum will cause a pitch touch and the temperature will not rise. Therefore, a coil pitch of 5 mm is optimal.

In this state, an electric current is passed through the vapor deposition coil 1,
When the vapor deposition coil 1 is heated, aluminum begins to melt, the molten aluminum accumulates at the bottom of the vapor deposition coil 1 due to surface tension, and further flows into the gap of the mounting coil 5 due to the capillary phenomenon, and the foot end of the bottom of the vapor deposition coil 1 Stay near part 2 '. The temperature of the aluminum clogged at the bottom of the vapor deposition coil 1 does not rise sharply because the current density near the foot end 2'is distributed to the foot end 2'and the mounting coil 5. Therefore, the vapor deposition coil 1 can extend the time to break the foot 2'and can retain a large amount of aluminum. That is, as a result, with this configuration, the life of the vapor deposition coil 1 is increased,
In addition, a large amount of aluminum can be vapor-deposited.

Next, when the vapor deposition coil 1 of the present invention was used (sample 1), the amount of evaporation of aluminum, the amount of spontaneous fall, and the amount of aluminum remaining in the vapor deposition coil 1 were measured. Conventional vapor deposition coil (Sample 1 is the vapor deposition coil 1 excluding the mounting coil 5 and is referred to as Sample 2)
The amount of evaporation of aluminum, the amount of spontaneous fall of aluminum, and the amount of aluminum remaining in the vapor deposition coil 1 were measured, and the measured values of both were compared. The measurement procedure will be described below.

In the sample 1, first, the foot ends 2 and 2 '(electrode terminals) of the vapor deposition coil 1 were clamped, a 2.5 g aluminum rod was loaded on the sample 1 and the sample 2, and the current was applied in a vacuum furnace. A current of 100 amps was applied. 60 seconds after the vapor deposition coil 1 reached the maximum temperature, the weight of the aluminum adhering to the vapor deposition coil at the bottom of the coil, the weight of the aluminum that naturally melted and did not evaporate, and the amount of evaporation of aluminum. Was measured respectively. On the other hand, also in Sample 2, the measurement was performed under the same condition settings as described above.

The set values of the vapor deposition coil used in Sample 1 are as follows: the vapor deposition coil has an inner diameter of 10 mm and a coil pitch of 5 m.
m, height from the top of the coil to the bottom is 30 mm, the length of both foot ends is 70 mm, the diameter of one of the three twisted wires of the vapor deposition coil is 1 mm, and it is attached to the vapor deposition coil 1 separately. The set value of the mounting coil 5 is that the wire diameter is 1 mm,
Inner diameter 3 mm, coil pitch 2 mm, coil length 20
mm. On the other hand, the vapor deposition coil used in Sample 2 is obtained by removing the mounting coil 5 from the vapor deposition coil 1 of Sample 1, and the specific set values are the same as those of Sample 1. Below, Table 1
The measurement results are shown in.

[0020]

[Table 1]

As can be seen from Table 1, the remaining amount of aluminum in the sample 1 using the vapor deposition coil 1 of the present invention is 0.1
At 5 g, the amount of evaporated aluminum was 2.35 g.

On the other hand, in the sample 2 using the conventional vapor deposition coil, after 20 seconds, aluminum dropped, the amount was 2.2 g, and the remaining amount of aluminum was 0.15.
The aluminum evaporation amount was 0.15 g. Thus, in Sample 2, aluminum was hardly evaporated.

Further, the coil setting conditions were the same as above, and the number of repetitions until disconnection was measured. As a result, Sample 1 was able to be used 8 times on average, 6 times at minimum, and 13 times at maximum for 10 coils. Sample 2
In the case of 10 coils, only the average of 3 to 4 times of evaporation could be performed, and thus it can be seen that Sample 1 is significantly improved in terms of the number of times of use.

As can be seen from the above measurement results, it is possible to evaporate about 2 g of aluminum in one shot, and the amount (0.1 to 0.3) that can be evaporated in one shot of the conventional case.
g) can be significantly improved, and the number of times of repeated use is also improved.

Although the vapor deposition coil 1 used in the embodiment of the present invention is made of tungsten, the present invention is not limited to tungsten, and a similar heat resistant metal coil such as molybdenum, tantalum, niobium, or titanium can be used. You can

The vapor deposition coil 1 of the present invention can be easily manufactured because the insertion coil 4 having a predetermined length is prepared and the attachment coil 5 is attached to one foot end portion 2'of the coil 1. it can.

[0027]

According to the present invention, the amount of aluminum vapor deposited once can be increased to 2 (g / hour) or more, and in the aluminum vapor-deposited plastic shield plate for magnetic shield used in computers etc. The shield property can be improved.

Further, since the molten aluminum which naturally falls becomes zero, a desired vapor deposition amount can be obtained. Since the bottom of the coil is reinforced by the mounting coil 5, even if the molten aluminum concentrates on the bottom of the coil, the effect of metal corrosion due to aluminum is mitigated. Therefore, the coil wire does not become thin and is not broken.

Further, since the current density at the foot end portion 2'diffuses into the mounting coil 5, the temperature of the aluminum clogged at the bottom of the vapor deposition coil 1 does not rise sharply. Therefore, abnormal heat generation at the bottom of the coil can be prevented, and the wire of the vapor deposition coil 1 does not become thin and is not broken.

[Brief description of drawings]

FIG. 1 (a) is a front view showing the structure of a vapor deposition coil used in the present invention, and FIG. 1 (b) is a top view of the vapor deposition coil of FIG. 1 (a).

FIG. 2 is a front view showing the structure of another vapor deposition coil used in the present invention.

FIG. 3 is a diagram showing a structure of a conventional vapor deposition coil.

FIG. 4 is a view showing the structure of another conventional vapor deposition coil.

FIG. 5 is a view showing the structure of another conventional vapor deposition coil.

FIG. 6 is a diagram showing the structure of another conventional vapor deposition coil.

FIG. 7 is a diagram showing the structure of another conventional vapor deposition coil.

[Explanation of symbols]

 1 vapor deposition coil 2, 2'foot end 3 coil part 4, 4 'coil end 5 mounting coil

Claims (2)

[Claims] 1. Winding is provided between the two coil end portions so as to enclose a space between the two coil end portions, the end regions being defined by the coil end portions and defining two coil end portions on both sides. In a vapor deposition coil having a heat-resistant metal coil portion and a foot end portion drawn out from each end portion, one of the foot end portions extends so as to cross the one end region. And a mounting coil attached to at least one of the foot end portions. 2. The vapor deposition coil according to claim 1,
The wire diameter of the mounting coil is 0.5 mm to 2.0 mm,
A vapor deposition coil, wherein the length of the coil in the mounting direction is equal to or greater than the outer diameter of the vapor deposition coil and equal to or less than 50 mm.