JPH042768A - Plasma electron beam heating apparatus - Google Patents

Abstract

PURPOSE:To allow large electric current to flow stably and uniformly from a vessel to a cooling member to easily control heat transmitting performance by combining the conductive vessel for the material to be heated with the recessed part of a cone-shaped conductive cooling member so as to leave a space between the vessel and the bottom part of the recessed part. CONSTITUTION:The plasma electron beams 15 from the electron gun 8 of hollow cathode irradiate the material 7 to be heated in the heat-resisting conductive vessel 6 disposed in contact with a water cooled copper hearth 5 of conductive cooling member so that the material is heated and evaporated. In this apparatus, the recessed part 26 in which the cross section becomes smaller in the direction of depth is formed in the hearth 5, and the vessel 6 is fitted in it, and the top end of the vessel 6 is hitted with a wooden hammer to be pressed enough. In this case, such a constitution is made that the vessel 6 does not reach the bottom of the recessed part 26 so that a spare space 17 is left. Thus, the vessel and the hearth are brought into contact with a part 18 of outer side wall of the vessel 6 where a large uniform contact pressure is given with the result that a good electrical and thermal conductivity is given between them.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to heating, melting, and degassing of materials, particularly for hollow cathodes used for heating evaporation sources in vacuum evaporation equipment, ion blating equipment, etc. The present invention relates to a plasma electron beam heating device.

[Prior Art] A configuration for heating an evaporation source using a conventional hollow cathode plasma electron beam heating device in an ion blating device is schematically shown in Fig. 1θ. In the figure,
(1) is a vacuum chamber equipped with a vacuum exhaust port (2), (3) is a substrate holder provided above the vacuum chamber (1), (4) is a substrate attached to the bottom surface of the substrate holder (3), (23) is a cooling hearth disposed inside the vacuum chamber (1) and facing the substrate (4); (22) is a recess (25) in the cooling hearth (23);
A heat-resistant conductive container (7) is placed inside the container (22
) is the material to be heated housed within the chamber.

Further, (8) is a hollow cathode electron gun, (9) is a hollow cathode, (20) is an auxiliary anode, and (10) is a DC power supply provided between the hollow cathode electron gun (8) and the cooling hearth (23). , (1)) indicate a high frequency generator, and (12) (12) indicate a high frequency bypass capacitor, respectively. High frequency generator (1)) and high frequency bypass capacitor (12)
(12) is connected in parallel with the DC power supply (lO). (
13) is a DC power supply for substrate bias, and (14) is a shutter (19) which is a variable resistor.

The material to be heated (7) is evaporated by the plasma electron beam (15) generated by supplying Ar gas to the hollow cathode electron gun (8) and applying voltage.
) A thin film of the heated material (7) is formed on the surface of the heated material (7).

An enlarged sectional view of the combination of the container (22) and the cooling hearth (23) is shown in Figure 1). As another conventional example, the first
FIG. 2 shows a cross-sectional view of an example in which the conductive container (22) is combined with the cooling block (24).

In either case, a voltage is applied to the plasma electron beam (1
5) is irradiated onto the material to be heated (7), the container (22
) and the cooling hearth (23) or cooling block (24) to ensure electrical and thermal continuity between the container (2
2) and to ensure continuity from the hollow cathode (9) to the cooling hearth (23) or cooling block (24) via the heated material (7) and container (22). It is.

In this case, the current flows from the hollow electrode (9) via the plasma electron beam (15) via the container (22) to the cooling hearth (23) or cooling block (24).

[Problem to be solved by the invention]

However, with the conventional type, it is difficult to obtain sufficient contact pressure between the container (22) and the cooling hearth (23) or the cooling block (24), which tends to cause poor conduction, and the generation of electric discharge is not certain. Ta. Furthermore, even if a discharge were to occur, there was a problem that sufficient current could not be passed through the cooling hearth (23) or the cooling block (24).
) and the cooling hearth (23) - At first glance, it seems as if the outer surface of the container (22) and the inner surface of the recess (25) of the cooling hearth (23) are in contact over a wide area, but in reality both are in contact. Due to the fine irregularities on the surface, the actual contact area is very small and the contact resistance is high. Therefore, in order to reduce the contact resistance by crushing the unevenness and increasing the substantial contact area, conventionally, after fitting the container (22) into the recess (25) of the cooling hearth (23), the container (22)
) with the edge of the cooling hearth (23) as shown by arrow a in the figure.
The contact pressure between the container (22) and the cooling part (23) was increased by hammering the cooling part (23) towards the container (22).

However, since the contact surface between the container (22) and the cooling hearth (23) is wide, the force is dispersed and sufficient contact pressure cannot be obtained, and a part of the bottom of the container (22) is not cooled. Hearth (2
When the bottom of the recess (25) in 3) is reached, no further container (22
) does not advance, so there is a drawback that sufficient contact pressure cannot be obtained. In addition, there is also the disadvantage that sometimes the conductive portions tend to be uneven, resulting in non-uniform current distribution.

Furthermore, as the container (22) is repeatedly heated and cooled,
There is also a drawback that the concave portion (25) of the cooling hearth (23) expands due to thermal expansion of the container (22), creating a gap between the cooling hearth (23) and the container (22), resulting in poor conduction.

In addition, in the conventional example shown in FIG. 12, the contact pressure between the container (22) and the cooling block (24) depends on the own weight of the container (22), so the material of the container (22) has a high specific gravity. It was necessary to select. Or, in order to increase the weight, it is necessary to thicken the walls of the container (22).
In this case, there are problems such as a reduction in the storage capacity of the material to be heated (7). In addition, even if a container with a specific cavity density and a wall thickness is used as described above, conduction defects are likely to occur, so the probability of discharge occurring is low, or even if discharge occurs, the current may not flow sufficiently. The disadvantage was that it occurred frequently.

In addition, in any of the above conventional examples, the contact surface between the container (22) and the cooling hearth (23) or the cooling block (24) is constant, and the contact pressure tends to be uneven. 22) and the cooling hearth (23) or the cooling block (24) is difficult to control.

The present invention was made in view of the above problems, and in order to reliably evaporate a desired amount of heated material at a constant rate, a large current is reliably and uniformly passed from a conductive heat-resistant container to a conductive cooling member. It is an object of the present invention to provide a hollow cathode plasma electron beam heating device that can reliably generate stable discharge by allowing the discharge to flow and by making it easy to control the heat transfer characteristics.

[Means to solve the problem]

The above purpose is to irradiate a plasma electron beam from a hollow cathode electron gun onto a material to be heated in a heat-resistant conductive container placed in contact with a conductive cooling member to heat and evaporate the material. In the heating device, a concave portion whose cross-sectional area gradually decreases in the depth direction is formed in the conductive cooling member, and when the conductive container is combined with the conductive cooling member, the conductive cooling member and the The contact surface with the conductive container is at least a part of the outer surface of the side wall of the conductive container, and the conductive container is configured to form a preliminary space between the bottom of the conductive container and the bottom of the recess. A plasma electron beam heating device characterized by the In the plasma electron beam heating device for evaporation, a recess whose cross-sectional area gradually decreases in a depth direction is formed in the conductive cooling member, and the conductive container is formed to fit into the recess. , when the conductive cooling member and the conductive container are combined, a conductive spacer is inserted between the side wall surface of the recess and the surface of the conductive container opposing thereto. The plasma is characterized in that the member and the conductive container are in contact with each other via the conductive spacer, and a preliminary space is formed between the bottom of the conductive container and the bottom of the recess. This is accomplished by an electron beam heating device.

[Function] In the plasma electron beam heating device configured as described above, when the plasma electron beam is irradiated from the hollow cathode electron gun toward the material to be heated in the heat-resistant conductive container, the plasma electron beam is emitted from the conductive container. A large current flows reliably and uniformly through the conductive cooling member, and heat conduction is also performed reliably, so that discharge is reliable and stable evaporation from the material to be heated is reliably obtained.

〔Example〕

Next, examples will be described with reference to the drawings.

FIG. 1 shows the overall configuration when a first embodiment of the combination of a conductive cooling member and a heat-resistant conductive container according to the present invention is applied to an ion blasting device. (5) is a water-cooled copper hearth, and (6) is a heat-resistant conductive container fitted into a mortar-shaped recess (26) of the water-cooled copper hearth (5), and is made of molybdenum (MO).

Granular magnesium fluoride (MgFt) is contained therein as a material to be heated (7). As shown in the figure, when the water-cooled copper hearth (5) and the conductive container (6) are fitted together and the upper end of the conductive container (6) is sufficiently pressurized by hitting it with a mallet, the conductive container (6) does not reach the bottom of the recess (26), leaving a spare space (17).

Moreover, both contact at a part of the outer surface of the side wall of the conductive container (6). This contact portion is indicated by (18). Other configurations are the first
Since this is common to the conventional example shown in the θ diagram, the same parts are given the same reference numerals.

FIG. 2 shows an enlarged sectional view of the conductive container (6), and FIG. 3 shows an enlarged sectional view of the water-cooled copper hearth (5).

The conductive container is mortar-shaped, and in Fig. 2, d =
62.5+am, e = 47ffim, h = 3
1n+s, t = 8mm.

θ,=14'. Concave part (26) of water-cooled copper hearth (5)
) It is mortar-shaped, and D = 60 mm in Fig. 3.
, E = 46+sm, F = 75mm, H = 2
8. I = 63mm.

θ2=14°. The conductive container (6) is placed in a water-cooled copper lotus (
When fitted into the recess (26) of 5), the conductive container (6)
A preliminary space (17) between the bottom of the recess (26) and the bottom of the recess (26).
occurs, and the height of the space is G = 2 mm.

Contact part (1) between the conductive container (6) and the water-cooled copper hearth (5)
8) is limited to a portion of the outer surface of the side wall of the conductive container (6) that fits into the recess (26) of the water-cooled copper hearth (5).

The operation of the apparatus configured as described above will be explained below with reference to FIG.

The inside of the vacuum chamber Tll is evacuated to 10-” Torr or less, and argon (Ar) gas is pumped into the hollow cathode electron gun (8) at 20-” Torr or less.
When the pressure inside the vacuum chamber (1) reaches 0.01 to 0.05 Torr, the hollow cathode electron gun (8), water-cooled copper hearth (5) and auxiliary anode (2o) are introduced at a flow rate of 0 to 3005 CCM. During this period, a voltage is generated by superimposing a high frequency voltage from a high frequency generator fil) on a DC voltage from a DC power source (lO). In this way, the Ar gas in the hollow cathode (9) excited by the superimposed high-frequency voltage is ionized and becomes plasma, and due to the action of the DC voltage, the ions in the plasma impact the inner wall of the hollow cathode and form a plasma. becomes incandescent, and the electrons in the plasma become a plasma electron beam (16) (15) from the opening at the tip of the hollow cathode and reach the auxiliary anode (
20) and the material to be heated [7) [MgFz]. Conductivity between the conductive container (6) and the water-cooled copper hearth (5) is ensured at the contact portion (18) by sufficient contact pressure, so that the tip of the hollow cathode (9) and the heated material (
7) and the conductive container (6). After the discharge starts, when the current value of the plasma electron beam is increased, the current flows from the conductive container (6) to the water-cooled copper hearth (5).
) flowed smoothly. The time until stable discharge starts is 1
minutes to several 10 minutes.

When the temperature of the material to be heated (7) and the conductive container (6) increases, the contact pressure at the contact portion (18) between the container (6) and the water-cooled copper hearth (5) increases due to thermal expansion of the container (6). However, as the temperature rises, the contact between the two surfaces becomes more reliable, reducing the contact resistance and allowing a larger current to flow.

In this example, a discharge current of 300 A or more could be stably passed through the water-cooled copper hearth (5) at a discharge voltage of 25 to 35 V. In addition, during ion blating, the material to be heated (
After preheating in step 7), the pressure inside the vacuum chamber is 3 to 7 x 10-
The discharge current was set at 80 to 160 A at Torr, and the MgF 2 of the material to be heated could be stably evaporated at a voltage of 28 to 38 V.

After the evaporation has stabilized, open the shutter (14) and release the substrate (
4) When MgF2 was vapor-deposited on top of the container (
The distance from the opening of 6) to the substrate (4) is 390 to 43
0+am, the deposition rate of MgF2 onto the substrate (4) is 120-130 nm/ll with a power of 5-6 Kw.
It was l1n.

When evaporation is completed and setting is performed for the next evaporation, if necessary, move the water-cooled copper hearth (5) to the container (6).
Even after repeated attachment and detachment operations, no inconvenience occurred.

As shown in Figure 1, the container (6) is connected to the water-cooled copper hearth (
When it is fitted into the recess (26) of 5) and press-fitted from above using a mallet, the contact portion (18) is limited to a part of the outer surface of the side wall of the container (6). Therefore, if the force applied from above is the same, the contact pressure increases in inverse proportion to the contact area, and the pressure distribution tends to be uniform in the contact area (18).

In addition, since the preliminary space (17) is provided, when the container (6) is press-fitted as in the conventional example, the bottom of the container (6) is in the recess (2).
6) The inconvenience of not being able to press-fit sufficiently because it gets stuck at the bottom is solved. Furthermore, by repeatedly using the container (6) and the water-cooled copper hearth (5), the recess (26)
Even if the container (6) expands, since the preliminary space (17) is provided, electrical and thermal conduction can be ensured by further press-fitting the container (6) with a mallet.

Also, looking at the heat conduction characteristics between the container (6) and the water-cooled copper hearth (5), assuming that the contact pressure is the same, the smaller the contact area of the contact part (18), the greater the amount of heat transferred by thermal conduction. Since the heating material (7) and the container (6) are heated less, the time required to heat the heated material (7) and the container (6) is shortened when the same electric power is input.

Next, a second embodiment will be described with reference to FIG. The conductive container (6
) and a water-cooled copper hearth (5), a conductive container (6) and a water-cooled copper hearth (5), the cross-sectional view of which is shown in FIG.
) was used in combination with Other configurations are common to the first embodiment.

In FIG. 4, parts having the same functions as those in FIGS. 1 to 3 are given the same reference numerals. The conductive container (6) in Fig. 4 is made of tungsten (W) and has a mortar-shaped side wall with two thicknesses, d = 62.5 mm, h =
31mm, t == 8mm, Δt = 1mm,
θ1=14°. The water-cooled copper hearth (5) is the same as that of the first embodiment shown in FIG. When the container (6) is fully press-fitted, the contact portion (18) is limited to a portion c = 14 mm, and the preliminary space ( 17) is G = 2m
It is m.

When the container (6) was filled with tablet-shaped zinc sulfide (Z, S) as a material to be heated for vapor deposition and irradiated and heated with a plasma electron beam under the same conditions as in the first example, ZnS was stabilized. I was able to evaporate it. The deposition rate of 2nS on the substrate (4) during evaporation was 90-130 at a power of 3-4KW.
It was nm/min. Other conditions are the same as in the first embodiment.

In this embodiment as well, the contact portion (1
It is clear that the electrical discharge occurred stably because the conductive container (6) and the water-cooled copper hearth (5) were securely contacted in step 8).

Furthermore, since the contact portion (18) of this embodiment is located at the upper part of the side wall of the container (6), cooling by heat conduction is efficiently performed at the upper part of the container (6). When the material to be heated (7) is irradiated with the plasma electron beam (15), the beam is also irradiated to the container (6), so especially when the evaporation temperature of the material to be heated (7) is high, ) It is necessary to efficiently cool the upper end part in order to prevent it from evaporating or melting, and the configuration of this embodiment is well suited for this purpose.

Next, a combination of a heat-resistant conductive container and a conductive cooling member will be described with respect to another embodiment. In either embodiment, the other configurations are the same as in the first embodiment. Also, second.
Parts that have the same functions as those in Figure 3 are given the same reference numerals. In all of the examples, sufficient contact pressure was obtained at the contact portion between the container and the cooling member when the container and the cooling member were press-fitted, so that reliable discharge was performed and the material to be heated was stably evaporated.

A sectional view of the configuration of the third embodiment is shown in FIG. The conductive container (6) is made of tantalum (Tal) and has a mortar-shaped bottom with a smaller mortar-shaped stand attached.

In the figure, the dimensions of the container (6) are d = 62.5 mm
, e”20mm, h+=33mm,
h2=7mm, t=6mm, θ1=14°. The water-cooling member is a water-cooled copper hearth (5) having a two-stage recess (26), and its dimensions are D = 60 mm, E =
20mm, F = 75mm, H+ = 28mn+
, H2 near 1) 1) ゜■ = 63mm, θ2 = 14
°. What is the container (6) and the water-cooled copper hearth (5)?
= 14mm and 02 = 5mrO, contact occurs at two locations, and two spare spaces (■) are also created. Spare space (17) is h2
=82, so both G=21)III+.

Similarly to the second embodiment, this embodiment can also efficiently cool the upper end of the container (6).

Next, a sectional view of the fourth embodiment is shown in FIG. The conductive container (6) of this example is made of molybdenum (MO) and has a mortar shape, and its dimensions are d=62.5 mm and e in the figure.
=46a+m, h = 33mm, t = 6+
mn, θ1=14°. The cooling member is a water-cooled copper hearth (5) having a mortar-shaped recess (26), and the dimensions are as follows.
D=60ma+, E=46a+m%F=75m
m, H=28mm, I=63n+m, θ2=1
It is 4°. When these are combined, use a heat-resistant, conductive, and flexible spacer, such as Figures 7A and 7B.
As shown in the figure, length 12 = 90mm, width w =
Flexible (
flexible) tungsten (w) spacer (2
1) around the outer periphery of the container (6) as shown in Fig. 8, and after fitting it into the recess (26) of the water-cooled copper hearth (5), use a mallet to tighten the upper end of the container (6). Push it in and press it in.

Because of the spacer (21), the container (6) and the recess (2
6), a preliminary space (17) given by G=Δt/sin θ1 is created. In this example, G=0.8
It is 3mm. Further, the contact portion (18) between the container (6) and the water-cooled copper hearth (5) is limited to the spacer (21).

Next, a fifth embodiment is shown in FIG. The present embodiment is an improvement on the conventional example shown in FIG. shaped recess (
26). In the figure, the dimensions of the container (6) are d = 62.5 mm, h r
= 33mm, h2 = 10mm, t=81)I
fl+, θ□=14°, water-cooled copper block (27)
The dimensions are F = 100a+m, I = 40mm,
H=10mm, E=201)II1), θ,=1
It is 4°. When the two are press-fitted together, as shown in the figure, a preliminary space (17) is created between the convex part on the bottom of the container (6) and the concave part (26) of the water-cooled copper block (27), and also in the concave part (26). It is structured so that it occurs in two places on the shoulder, and there is a spare space (17).

=H, so G = 2mm in both cases. Further, the contact portion (18) between the two is limited to a portion where c=8 mm.

Among the above embodiments, when the evaporation temperature of the material to be heated is high, it is necessary to efficiently cool the upper end of the container (6), so the embodiments shown in FIGS. 1, 4, and 8 is suitable. On the other hand, the evaporation temperature of the material to be heated is relatively low, and the container (6
) The embodiments shown in FIGS. 6 and 9 are suitable if it is better to raise the entire body to that relatively low temperature. This is because the amount of heat radiated through the contact portion (18) is small, so the time required for heating is shortened. Further, even if the area of the contact portion (18) is small, a large current can be passed if necessary.

Although each embodiment of the present invention has been described above, the present invention is of course not limited to these (and various modifications can be made based on the technical idea of the present invention).

For example, heat-resistant conductive containers and conductive spacers include tantalum, tungsten, molybdenum, graphite, and high-melting point metals such as niobium, rhenium, and hafnium.
Conductive high melting point compounds such as boron nitride, tantalum carbide, titanium carbide, tungsten carbide, zirconium carbide, tantalum boride, etc., or high melting point conductors containing these as main components can be used.

In addition, although a homogeneous spacer made of tungsten was used in the embodiment, instead, a spacer made of tungsten may be made of a material made of tungsten that is continuous or discontinuous in the thickness direction from the surface in contact with the conductive container to the surface in contact with the conductive cooling member. may change.

Further, a layer of a material used for a spacer may be formed on either or each surface where the conductive container and the conductive cooling member are in contact with each other.

Further, the contact portion between the conductive container and the conductive cooling member is not limited to a surface, but may be linear or dotted. The spacer also does not need to cover the entire circumference of the side wall of the container, and may be divided into a plurality of pieces and placed in a distributed manner.

For example, in the case where the contact portion between the conductive container and the conductive cooling member covers the entire circumference of a part of the side wall of the container as in the first embodiment, a through hole may be provided at the bottom of the recess of the cooling member, or a through hole may be provided at the bottom of the concave portion of the cooling member. It is preferable to provide a groove on the outer surface of the side wall extending from the bottom of the container to the top.

As a result, even if the container and cooling member are fitted together in the atmosphere using a mallet and then evacuated in a vacuum chamber, the fitting between the two will not loosen (the contact between the two will be improved). It can be made certain.

Further, as the hollow cathode electron gun, one without an auxiliary anode, or one using a magnetic field or electric field for converging or deflecting the plasma electron beam can also be used.

Further, as the material to be heated, any of conductors, semiconductors, and non-conductors such as nonmetals, dielectrics, and ceramics can be used.

Furthermore, although the concave portion of the conductive cooling member is formed so that the cross-sectional area gradually decreases in the depth direction, there may be a portion in the middle or in the preliminary space where the cross-sectional area does not decrease, as shown in FIG. It is sufficient if the structure is such that the cross-sectional area of the structure is reduced.

[Effects of the Invention] Since the present invention has the above-described configuration, when a heat-resistant conductive container is press-fitted into the recess of the conductive cooling member, a uniform and large contact pressure is obtained, and the electrical connection between the two is reduced. Improves thermal conduction. Therefore, when a plasma electron beam is irradiated from the hollow cathode electron gun toward the material to be heated, a large current can be stably and uniformly passed from the conductive container to the conductive cooling member, and discharge generation is ensured. Even if the conductive container and the conductive cooling member are used repeatedly, the above effects remain unchanged. Furthermore, the cooling means for the conductive container can be easily controlled. Further, since the structure of the present invention is relatively simple, great effects can be obtained with low manufacturing costs.

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing the configuration when the first embodiment of the present invention is applied to an ion brating device, and Figs. 2 and 3 respectively show the conductive container and water-cooled copper of the first embodiment. 4 is a sectional view of the second embodiment, FIG. 5 is a sectional view of the third embodiment, FIG. 6 is a sectional view of the fourth embodiment,
7A and 7B are a plan view and a cross-sectional view of a spacer used in the fourth embodiment, FIG. 8 is a perspective view showing the spacer assembled with a conductive container, and FIG. 9 is a cross-sectional view of the fifth embodiment. Figure 1) is a diagram schematically showing the configuration when a combination of a conventional conductive container and a water-cooled copper hearth is applied to an ion brating device. FIG. 12 is a sectional view of a combination of a conventional conductive container and a water-cooled copper block. In the figure, 5)・・・・・・・・・・・・ 6)・・・・・・・・・・・・ 8)・・・・・・・・・・・・ 15 ・・・・・・・・・・・・・・・ 17 ・・・・・・・・・・・・ 18 ・・・・・・・・・・・・ Water-cooled copper hearth Conductive container Hollow cathode electron gun Plasma electron beam Reserve Air Indirect contact Water-cooled copper block Figure 4 Figure 8 Figure 27 Water-cooled copper block Figure 10

Claims (6)

[Claims] (1) Plasma electron beam heating in which the material to be heated in a heat-resistant conductive container placed in contact with a conductive cooling member is irradiated with a plasma electron beam from a hollow cathode electron gun to heat and evaporate the material. In the apparatus, a concave portion whose cross-sectional area gradually decreases in the depth direction is formed in the conductive cooling member, and when the conductive container is combined with the conductive cooling member, the conductive cooling member and the conductive The contact surface with the conductive container is at least a portion of the outer surface of the side wall of the conductive container, and the conductive container is configured to form a preliminary space between the bottom of the conductive container and the bottom of the recess. Characteristic plasma electron beam heating device. (2) Plasma electron beam heating in which the material to be heated in a heat-resistant conductive container placed in contact with a conductive cooling member is irradiated with a plasma electron beam from a hollow cathode electron gun to heat and evaporate the material. In the apparatus, a recess whose cross-sectional area gradually decreases in the depth direction is formed in the conductive cooling member, the conductive container is formed to fit in the recess, and the conductive cooling member and the conductive When combining the conductive cooling member and the conductive container, a conductive spacer is inserted between the side wall surface of the recess and the surface of the conductive container opposing thereto. A plasma electron beam heating device characterized in that the plasma electron beam heating device is configured to make contact via a conductive spacer and to form a preliminary space between the bottom of the conductive container and the bottom of the recess. (3) The conductive container and the conductive spacer are any one of a conductive high melting point material, a high melting point metal, and a conductive high melting point compound, or a high melting point conductor containing any of these as a main component. The plasma electron beam heating device according to (1) or (2). (4) The plasma electron beam heating device according to claim (3), wherein the conductive high melting point material is graphite. (5) The plasma electron beam heating device according to claim 3, wherein the high melting point metal is tungsten, tantalum, rhenium, molybdenum, niobium, or hafnium. (6) The plasma electron beam heating device according to (3), wherein the conductive high melting point compound is boron nitride, tantalum carbide, titanium carbide, tungsten carbide, zirconium carbide, or tantalum boride.