JPH11335833A - Substrate heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of films grown on a substrate by providing the substrate heater with a magnetic field erasing means for erasing a first magnetic field on at least one surface side of the substrate by generating a second magnetic field in the direction reverse from the direction of the first magnetic field generated by energization to a heating means for heating the substrate. SOLUTION: When a power source is connected to a point A and a point C and energization is executed, the currents in the directions reverse from each other flow in the two conductive patterns like from the point A to the point B in, for example, the conductive pattern 28a and from the point B' to the point C in the conductive pattern 28b. Consequently, the magnetic field generated by the current flowing in the conductive pattern 28a and the magnetic field generated by the current flowing in the conductive pattern 28b are reversed in the directions from each other and the former is negated by the latter on the periphery of the side where the film deposition of the substrate is executed. Then, the intermittent generation of the magnetic fields on the periphery of the substrate and the consequent bending of the loci of electron beams and the hindrance of the observation of the substrate surface by electron beam diffraction do not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a substrate heating apparatus used in a vacuum processing apparatus.

[0002]

2. Description of the Related Art Recently, in a vacuum processing apparatus such as a molecular beam epitaxy growth apparatus (hereinafter referred to as "MBE apparatus"),
2. Description of the Related Art Filming and other processing on a substrate such as silicon (Si) or gallium arsenide (GaAs) are actively performed. FIG. 5 is a diagram illustrating a configuration of a general MBE device. As shown in the figure, the MBE apparatus includes a growth chamber for actually performing crystal growth, and a spare chamber for allowing a substrate to be taken in and out while maintaining the degree of vacuum in the growth chamber. The growth chamber includes a substrate heating apparatus 100 for supporting and heating the substrate, a molecular beam source 142 for irradiating molecules or atoms onto the substrate to grow crystals, and an in-situ observation of the substrate surface by reflection high-energy electron diffraction (RHEED). Equipment.
Here, the equipment for observation by RHEED is an electron gun 144 that makes an accelerated electron beam incident on the substrate surface at a small irradiation angle.
And a screen (fluorescent plate) 146 for observing the diffraction pattern of the electron beam scattered on the substrate surface.

FIG. 6 shows an MBE including a substrate heating apparatus 100.
It is sectional drawing which shows a part of apparatus. 6, a substrate holder 106 is a member that holds a molybdenum block (hereinafter, referred to as “MOB”) 104 to which the substrate 102 is attached. The substrate holder 106 is attached to a hollow rotary shaft 114 rotatable about its main axis so as to be integrated in the rotation direction.

A heater support 112 is disposed on the inner peripheral side of the hollow rotary shaft 114. The heater support 114 supports the heater 124 at its tip. The heater 124 is an MOB held by the substrate holder 106.
A means for heating 104, usually a MOB 10
4 is arranged parallel to the lower surface, and consequently also to the substrate 102. FIG. 7 is a top view of the heater 124. FIG. 7A shows a heater 124a in which a conductive pattern 128a made of a tantalum sheet is provided on a tantalum plate 126a using a pyrolytic boron nitride (pBN) glass 130.
As shown in FIG. 8, the pBN glass 130 is provided with a groove for supporting the tantalum sheet 128a on the side surface of the block-shaped pBN glass. FIG.
(A) is an example of a heater different from that shown in FIG.
This shows a heater 124b in which a conductive pattern made of a tantalum wire 128b is provided on an N insulating plate 126b.

[0005] As shown in FIG.
0, the thermocouple 108 supported by the protection tube 110
Is further provided. The protection tube 110 is arranged along the main axis of the hollow rotary shaft 114, and has a spring receiving ring 120 at a lower portion thereof. The spring receiving ring 120 receives a force toward the MOB 104 from a spring 122 disposed around one end of the protective tube 110. Therefore, thermocouple 108
Are constantly pressed and in contact with the lower surface of the MOB 104.

[0006] The protective tube 110 is hollow, and the lead wire of the thermocouple 108 and the lead wire of the heater 124 are connected to a PID temperature controller for controlling the temperature of the heater through the hollow portions. The PID temperature controller performs PID control (Proportional integral) based on the output signal of the thermocouple 108.
and Derivative control) to adjust the amount of current supplied to the heater 124. The reason for using the PID temperature controller in this way is that the quality of the film grown on the substrate greatly depends on the substrate temperature at that time, and in order to improve the film quality, the temperature of the substrate 102 is extremely strictly controlled. It is necessary.

[0007] When a film is formed on a substrate in the MBE apparatus or other processing is performed, an in-situ observation of the substrate surface by RHEED is performed. For example, in the case of heat treatment of the substrate performed before film formation to remove the oxide film on the substrate surface, in-situ observation of the substrate surface is performed to confirm the completion of the oxide film removal. This is because if the heat treatment is not stopped at the time of completion of the oxide film removal, the surface of the substrate is roughened, and the quality of the film grown on the substrate is deteriorated thereafter. For example, in a substrate made of gallium arsenide (GaAs), G
The decomposition of a and As occurs, and a desired rearrangement pattern cannot be obtained even if a crystal is grown on the substrate thereafter. The in-situ observation of the substrate surface is performed by irradiating the substrate with an electron beam from an electron gun for RHEED and observing the diffraction pattern of the electron beam scattered on the substrate surface with the above-mentioned screen (fluorescent plate). While the oxide film is on the substrate surface, a ring-shaped pattern, which is an amorphous or polycrystalline diffraction pattern, is observed on the screen. On the other hand, when the oxide film is removed, a superlattice structure, which is a rearrangement pattern peculiar to the single crystal surface, appears on the screen. Therefore, when the super lattice structure appears, it is determined that the oxide film has been removed from the substrate surface, and the oxide film removing step is terminated.

[0008]

However, in the conventional vacuum processing apparatus described above, a large current of about 10 A flows intermittently through the heater because the PID temperature controller controls the temperature of the heater. In situ observations were often hindered. That is, the current flowing through the heater intermittently generates a magnetic field 134 near the surface of the substrate 102 as schematically shown in FIG. Bending, resulting in RHEE
D makes accurate observations impossible. For this reason, when removing the oxide film from the substrate, there has been a problem that the end point of the oxide film removal cannot be accurately detected and the substrate surface may be roughened. Also, when a film is formed on a substrate, there is a problem that it is difficult to obtain a high quality film because the arrangement of surface atoms in the growing film cannot be clearly observed. When the temperature is controlled using the PID temperature controller, the current flows through the heater at a cycle of about 0.1 Hz, so that the probability of obstructing the observation by RHEED is high, and the above problem is extremely serious.

Further, the above-described vacuum processing apparatus has a problem that the thermocouple is easily broken. Usually, the substrate 102
Is rotated together with the MOB 104 by applying rotational power to the hollow rotary shaft 114 shown in FIG. This is for forming a uniform film on the substrate surface. on the other hand,
The thermocouple 108 is formed at the tip of a lead wire 136 extending from the protective tube 110 as shown in FIG. 10A, and is generally not rotated for reasons such as to prevent twisting of the lead wire. It is. As described above, the thermocouple 108 is pressed against the lower surface of the MOB 104 by the force of the spring 122 shown in FIG. Therefore, when the MOB 104 rotates, a rotational torque is applied to the thermocouple 108 and the lead wire 136. As a result, as shown in FIG. 10B, the lead wire 136 goes out of the protective tube 110. It was easy to break in the position.

When the thermocouple is cut as described above,
After the growth chamber is once returned to the atmospheric pressure, the growth chamber is depressurized again after the thermocouple is replaced. Here, in order to reduce the growth chamber to a required pressure, for example, 10 ^-10 Torr, it takes a very long period of about two weeks, so that the thermocouple exchange greatly affects the production efficiency. The problem of fragile pairs was also very serious. In order to solve the above problem, it is conceivable that the thermocouple is not directly contacted with the MOB.
In this case, an error of 20 to 30 ° C. occurs in the measured temperature, and it becomes impossible to precisely control the substrate temperature.
As a result, the quality of the film deteriorates, so that the problem cannot be solved properly.

Accordingly, the present invention provides a substrate heating apparatus in which a magnetic field does not affect the substrate surface, and also provides a substrate heating apparatus which can accurately measure the substrate temperature and has temperature measuring means with few failures. Accordingly, it is an object to improve the quality of a film grown on a substrate in a vacuum processing apparatus.

[0012]

In order to solve the above-mentioned problems, a substrate heating apparatus according to the present invention includes a heating means for heating a substrate supported in a vacuum processing apparatus by energizing a conductive portion; Magnetic field erasing means for erasing the first magnetic field on at least one side of the substrate by generating a second magnetic field opposite to the first magnetic field generated by energizing the heating means. Here, the magnetic field erasing means is
By providing a magnetic field erasing conductive part capable of supplying a current in a direction parallel to and opposite to the current supplied to the conductive part of the heating means, by applying a current to the magnetic field erasing conductive part, the first A second magnetic field opposite to the magnetic field can be easily generated. Further, the conductive part for magnetic field erasing has the same shape as the conductive part of the heating means, and is arranged at a position where the conductive part of the heating means is moved in parallel to the normal direction of the surface of the substrate. Then, the first magnetic field can be erased on the entire surface of the substrate.

Further, the substrate heating apparatus according to the present invention comprises a heating means for heating a substrate supported in a vacuum processing apparatus by energizing a conductive portion, and a soft magnetic member disposed between the substrate and the heating means. And the soft magnetic member prevents a magnetic field generated by energizing the heating means from reaching the substrate. In such a substrate heating device, the lines of magnetic force generated by the heating means are caught by the soft magnetic member and cannot reach a certain side of the substrate. Further, the above-described substrate heating apparatus erases the first magnetic field on at least one side of the substrate by generating a second magnetic field opposite to the first magnetic field generated by energizing the heating means. The magnetic field erasing means may be further provided. In such a substrate heating apparatus, even when the substrate is heated to a temperature higher than the Curie temperature of the soft magnetic member, the magnetic field on the substrate surface can be effectively erased by the magnetic field erasing means.

Further, the substrate heating apparatus according to the present invention comprises a substrate holding means capable of rotating and holding a substrate in a vacuum processing apparatus for heating, a temperature measuring means for measuring the temperature of the substrate holding means, and a substrate holding means. A torque interrupting means for preventing rotation torque from being transmitted from the substrate holding means to the temperature measuring means by making contact with the means so as to make relative movement and contacting with the temperature measuring means so as to make relative movement impossible. In such a substrate heating device, while the heat of the substrate holding means is transmitted to the temperature measuring means via the torque interrupting means, the torque interrupting means performs relative movement with the substrate holding means, so that the rotation of the substrate holding means is performed. The movement is not transmitted to the torque shut-off means and thus to the temperature measuring means.

Here, if the torque interrupting means is made of a metal material, the heat transfer coefficient from the substrate holding means to the temperature measuring means is improved, and the temperature measuring accuracy can be improved. Further, if the torque cutoff means is elastically contacted with the temperature measurement means, the torque cutoff means can maintain contact with the temperature measurement means against the frictional force received from the rotating substrate holding means, Further, it is possible to manufacture a torque interrupting unit that reliably contacts the temperature measuring unit even when processing the torque interrupting unit without requiring very strict shape accuracy.

Further, if the torque interrupting means has an annular portion fitted to the outer periphery of the supporting means for supporting the temperature measuring means, the torque interrupting means can be easily attached to the temperature measuring means. Further, if the supporting means and the annular portion have a rotation preventing irregular portion for preventing the annular portion from rotating with respect to the supporting means by contact with each other, the rotation of the substrate holding means also rotates the torque interrupting means. However, it is possible to reliably prevent a situation in which the rotation relative to the temperature measurement unit is caused. In particular, if the rotation preventing deformed portion is a flat surface, it is possible to obtain a rotation preventing deformed portion that reliably prevents relative rotation between the torque cutoff means and the temperature measuring means by a simple processing step. In addition, the mounting of the torque interrupting means to the temperature measuring means is not hindered.

Further, the support means and the annular portion may have a falling-off preventing deformed portion for preventing the annular member from falling off from the support means by coming into contact with each other. In particular, if the falling-off preventing deformed portion is a groove provided on the support means and a convex portion provided on the annular portion and can be inserted into the groove, the deforming portion for preventing falling off can be easily processed in this case as well. It can be obtained by the process, and furthermore, the ease of mounting the torque cutoff means to the temperature measurement means is not hindered.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the substrate heating apparatus according to the present invention will be described in more detail with reference to the drawings and the like. In the following description, substantially the same parts and members as those of the above-described conventional device are denoted by the same reference numerals, and redundant description will be omitted.

(First Embodiment) First, a first embodiment of the substrate heating apparatus according to the present invention will be described. The first embodiment of the present invention is characterized in that, as heaters for heating the MOB, two conductive patterns having the same shape and arranged in parallel to each other are used, and currents in opposite directions are supplied to the respective conductive patterns.

FIG. 1 is a perspective view showing two conductive patterns 28a and 28b used in the present embodiment. The two conductive patterns 28a and 28b are both tantalum sheets having the same shape as the conductive pattern 128a shown in FIG. 7A, and are arranged on a tantalum plate 126a as in a conventional substrate heating device. Conductive pattern 28a
2 and 28b are attached to the tantalum plate 126a using the pBN glass 30 shown in FIG.

The pBN glass 30 is a conventional pBN glass shown in FIG.
It is equivalent to BN glass 130, but pBN glass 1
The pBN glass 30 has two sets of grooves 30a and 30b for supporting the conductive patterns 28a and 28b, respectively, while the 30 has only one set of grooves 130a for supporting one conductive pattern on its side. They differ in that they have on their side. The conductive pattern 28a is supported by the groove 30a of the pBN glass 30 so that the MOB 10
4 near and parallel to the lower surface, in other words, the substrate 1
02 is arranged in parallel to the surface on which the film is formed. on the other hand,
The conductive pattern 28b is formed in the groove 30b of the pBN glass 30.
That is, the conductive pattern 28a is supported at a position parallel-moved by a predetermined distance in a direction away from the substrate 102 along the normal line of the upper surface of the substrate 102. The conductive patterns 28a and 28b arranged as described above are connected to each other by spot welding at points B and B 'shown in FIG.

In the conductive pattern configured as described above, power is connected to points A and C in FIG. In this case, for example, in the conductive pattern 28a, A
In the conductive pattern 28b, currents flowing in opposite directions flow from the point B to the point B, and from the point B 'to the point C in the conductive pattern 28b. As a result, the directions of the magnetic field generated by the current flowing through the conductive pattern 28a and the magnetic field generated by the current flowing through the conductive pattern 28b are opposite to each other around the surface of the substrate 102 on which the film is formed. Canceled by

Therefore, in the substrate heating apparatus according to the present embodiment, the magnetic field is generated intermittently around the substrate, and the trajectory of the electron beam is bent, thereby obstructing the observation of the substrate surface by electron beam diffraction. Absent. Moreover, in the present embodiment, since the conductive pattern 28a has the same shape as the conductive pattern 128a used in the conventional device, it is different from the conventional device in that the substrate is uniformly heated. The above problem is solved without any inferiority. Further, since the conductive pattern 28b provided to cancel the magnetic field has the same shape as the conductive pattern 28a, the manufacture thereof is extremely easy. The substrate heating apparatus of this embodiment differs from the conventional apparatus in that conductive patterns 28a and 28b and pBN glass 30 are used in place of conductive pattern 128 and pBN glass 130. 6 is substantially the same as the conventional device described in FIG.

(Modification of First Embodiment) In the above description, the case where the conductive patterns 28a and 28b are electrically connected at the points B and B 'in FIG. 1 has been described. They need not necessarily be connected to each other. In the substrate heating apparatus of the present embodiment, it is only necessary to obtain two currents flowing in parallel and in opposite directions. Therefore, the two conductive patterns are insulated from each other and are connected to independent power sources, respectively. You may. In this case, even when the distance between the two conductive patterns is large, each conductive pattern is so arranged that the magnetic field around the substrate caused by each conductive pattern has substantially the same intensity. There is an advantage that the amount of current to the power supply can be adjusted independently. The shape of the conductive pattern 28b is not necessarily the shape of the conductive pattern 28b.
It does not need to be the same as a. For example, when the observation by RHEED is performed only at the central portion of the substrate where the temperature is relatively uniform for reasons such as improvement in reproducibility, the shape of the conductive pattern 28b is changed so that the magnetic field is canceled only at the central portion of the substrate. May be.

(Second Embodiment) Next, a second embodiment of the substrate heating apparatus according to the present invention will be described. The substrate heating apparatus of the present embodiment prevents the magnetic field generated in the heater from reaching the substrate by arranging the soft magnetic material in the MOB. FIG. 3A is a partial cross-sectional view of the MOB 4 used in the present embodiment, and FIG.
FIG. 4 is a diagram schematically illustrating a locus of an electron beam 132 around an OB and a state of a magnetic field 134. As shown in FIG.
The MOB 4 used in this embodiment includes a flat soft magnetic body 38 therein. As the soft magnetic body 38, a permalloy alloy (FeNi), a sendust alloy (FeA)
1Si) or a material having a large saturation magnetic flux density such as a Mn-Zn ferrite magnetic material. The soft magnetic body 38 is
It is preferable that the substrate has a shape larger in area than the substrate 102 attached on the MOB 4.

In the MOB having the above configuration, FIG.
As shown in (b), since the soft magnetic body 38 is located between the heater 124 and the substrate 102, the lines of magnetic force 134 generated by the heater 124 preferentially pass through the soft magnetic body 38 having a higher magnetic permeability than the surroundings. The magnetic field does not reach the substrate 102 because it passes through and returns to the heater 124. For example, in the case where a magnetic field of 500 gauss is measured on the upper surface of the MOB of the conventional apparatus, if a permalloy-based alloy having a thickness of 3 mm is used as the soft magnetic body 38, the magnetic field does not reach the substrate surface. Therefore, even when the heater 124 is energized, the trajectory of the electron beam 132 irradiated on the surface of the substrate 102 is prevented from being bent, and the observation of the substrate surface becomes impossible. In particular, when a metal soft magnetic material is used as the soft magnetic material 38, it is possible to make the temperature distribution of the MOB 4 uniform, and thereby promote the uniformization of the substrate temperature. The substrate heating apparatus according to the present embodiment is different from the conventional apparatus in that the MOB 4 is provided with the soft magnetic material 38 as described above, but the other configuration is the same as the conventional apparatus described with reference to FIG. It is substantially the same as the device described above.

(Modification of Second Embodiment) The case where the soft magnetic body 38 on the flat plate is arranged inside the MOB 4 has been described above, but the soft magnetic body 38 is provided between the heater 124 and the substrate 102. Since the effect of the present invention can be obtained if it is located, the arrangement position and shape are not limited to those described above. For example, the soft magnetic material may be formed of a hollow block, and the heater 124 may be arranged in the hollow portion. Also, instead of attaching the soft magnetic material to the MOB,
For example, it may be attached to the substrate holder 106. In addition, the present embodiment is combined with the first embodiment of the present invention, that is, a soft magnetic material is arranged between the heater 124 and the substrate 102, and the heater is formed of two conductive patterns arranged in parallel, Currents in opposite directions may be applied to the conductive patterns. This makes it possible to more effectively prevent the magnetic field from reaching the substrate surface. Further, even when the MOB is heated to a temperature equal to or higher than the Curie temperature of the soft magnetic body 38, the two conductive patterns arranged in parallel cancel each other out of the magnetic field generated by each other. The range of use can be expanded.

(Third Embodiment) Next, a third embodiment of the substrate heating apparatus according to the present invention will be described. The third embodiment of the present invention is characterized in that a means for preventing a rotating torque from being applied to a thermocouple from a rotating MOB is provided. FIG. 4 is a perspective view showing the thermocouple, the protection tube of the thermocouple, and the protection cap used in the present embodiment. The protection tube 10 is an insulating tube made of ceramics, and has two flat portions 10b parallel to each other on the outer peripheral surface of the distal end portion. The flat portion 10b has a length of 5 mm from the tip of the protection tube 10 and is provided in parallel with a hole in the protection tube through which a thermocouple made of tungsten / rhenium (W / Re) passes. Further, the rear end of the flat portion 10b has a width of 0.5 m.
A groove 10d having a depth of 0.2 mm and a depth of 0.2 mm is provided by grinding with a dicer.

The protective cap 40 is installed on the protective tube 10, and a part of the protective cap 40 is brought into contact with the thermocouple 8, and another part is brought into contact with the lower surface of the MOB 104.
It is a member that enables heat conduction from the thermocouple 04 to the thermocouple 8.
The protective cap 40 is made of a high melting point metal, for example, 0.3 m thick.
It is obtained by cutting out a tungsten plate of m. The protection cap 40 includes an annular portion 40a,
It also has two flat portions 40b, some of which also serve as annular portions 40a, and a flat contact portion 40c extending forward from the flat portion 40b.

When the protective cap 40 is attached to the protective tube 10, the annular portion 40 is a portion that partially or entirely fits on the outer peripheral surface of the distal end of the protective tube 10. Two flat portions 40
b are provided so as to face each other, and are portions that respectively overlap the two flat portions 10b of the protection tube when the protection cap 40 is attached to the protection tube 10. The flat plate portion 40b is, together with the flat portion 10b, a protective cap 4
0 constitutes a rotation-preventing deformed portion for preventing rotation with respect to the protection tube 10. Further, a projection 40 d formed by bending a part of the flat portion 40 b toward the inside of the protective cap 40 is provided at the tip of the flat portion 40 b. The protrusion 40d is located in a groove 10d provided in the protection tube 10 when the protection cap 40 is attached to the protection tube 10. The protrusion 40d and the groove 1
Od forms a deformed portion that prevents the protective cap 40 from falling off the protective tube 10.

As is apparent from FIG.
Ob protrudes rearward from the annular portion 40a. When the protection cap 40 is attached to the protection tube 10, the flat portion 40b can be wider than the annular portion 40a at the projecting portion, thereby facilitating the attachment of the protection cap 40 to the protection tube 10.

The contact portion 40c is in contact with the thermocouple 8 on its inner surface, and has a MOB 10
4 is a portion that comes into contact with the lower surface. The contact portion 40c has a folded portion between the contact portion 40c and the flat portion 40b, and is bent such that the interval between the tip portions is smaller than the diameter of the thermocouple 8. Due to the presence of the folded portion, the contact portion 40c has elasticity to bend inside the protective cap. Therefore,
The contact portion 40c reliably contacts the thermocouple 8 without forming the protective cap 40 with particularly high precision. Also, the contact portion 4
Even when a force is applied to MOC from MOB 104, contact portion 40 does not separate from the thermocouple.

The protection tube 10 is a protection tube 110 of a conventional device.
In the same manner as described above, a force in the direction toward the MOB 104 is received from the spring 122. Therefore, the protective cap 40 is also attached to the spring 12.
2 is received via the protective tube 10, whereby the tip of the contact portion 40c always contacts the lower surface of the MOB 104 at a predetermined pressure. Here, the predetermined pressure refers to a pressure at which the MOB 104 and the protective cap 40 come into sliding contact with each other.

In the present embodiment, the protection cap 40 is attached to the protection tube 10 as described above.
The heat of B104 is transmitted to the thermocouple through the protective cap 40 by heat conduction. Here, since the protective cap 40 is made of a metal material having a high thermal conductivity such as tungsten as described above, the thermocouple 8 can accurately measure the temperature of the MOB 104 regardless of the presence of the protective cap 40. Can be. On the other hand, when the MOB 104 is rotated to make the film growth on the substrate 102 uniform, the MO
Sliding occurs between B104 and the protective cap 40. Due to this slip, the rotational torque is not applied directly from the MOB 104 to the thermocouple 8, and the lead wire 36 of the thermocouple 8
Is prevented from being disconnected.

The substrate heating apparatus according to the present embodiment differs from the conventional apparatus in that the protective cap is used as described above and that the tip of the protective tube is specially processed to attach the protective cap. However, the other configuration is substantially the same as the conventional device described with reference to FIG.

[0036]

As described above in detail, according to the present invention, no magnetic field is generated around the surface of the substrate by energizing the substrate heating device, so that the substrate surface can be observed by the electron beam diffraction method. By observing the surface of the substrate accurately at all times, it was possible to grow a high-quality film on the substrate. Further, according to the present invention, without lowering the measurement accuracy of the temperature measuring means,
Since the failure of the temperature measuring means can be prevented, it is possible to improve the film production efficiency while maintaining the quality of the film grown on the substrate high.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a conductive pattern used in a first embodiment of the present invention.

FIG. 2 is a perspective view showing a pBN glass used in the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a MOB used in a second embodiment of the present invention, and a schematic diagram showing a trajectory and a magnetic field of an electron beam around the MOB.

FIG. 4 is a perspective view showing a thermocouple, a thermocouple protection tube and a protection cap used in a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a general MBE device.

FIG. 6 is a partial cross-sectional view including a substrate heating device of a conventional MBE device.

FIG. 7 is a top view of a heater used in a conventional substrate heating apparatus.

FIG. 8 shows the pB used in the heater shown in FIG.
It is a perspective view which shows N glass.

FIG. 9 is a diagram showing a magnetic field generated by a conventional substrate heating apparatus and a trajectory of an electron beam applied to a substrate.

FIG. 10 is a perspective view showing a thermocouple used in a conventional substrate heating device and its protection tube.

[Explanation of symbols]

 4 MOB 8 Thermocouple 10 Protective tube 10b Flat portion 10d Groove portion 28a, 28b Conductive pattern 30 pBN glass 36 Lead wire 38 Soft magnetic material 40 Protective cap 40a Annular portion 40b Plate portion 40c Contact portion 40d Projection portion 100 Substrate heating device

Claims (5)

[Claims] 1. A heating unit for heating a substrate supported in a vacuum processing apparatus by energizing a conductive unit, and a second magnetic field opposite to a first magnetic field generated by energizing the heating unit. And a magnetic field erasing means for erasing the first magnetic field on at least one surface side of the substrate by generating the substrate. 2. The magnetic field erasing means according to claim 1, wherein the magnetic field erasing means is a magnetic field erasing conductive part for supplying a current in a direction parallel and opposite to a current supplied to the conductive part of the heating means.
A substrate heating device according to claim 1. 3. A heating means for heating a substrate supported in a vacuum processing apparatus by energizing a conductive part, and a soft magnetic member disposed between the substrate and the heating means. The substrate heating device, wherein the member prevents a magnetic field generated by energizing the heating means from reaching the substrate. 4. By generating a second magnetic field in a direction opposite to the first magnetic field generated by energizing the heating means,
4. The substrate heating apparatus according to claim 3, further comprising a magnetic field erasing means for erasing the first magnetic field on at least one surface of the substrate. 5. A rotatable substrate holding means for holding and heating a substrate in a vacuum processing apparatus; a temperature measuring means for measuring a temperature of the substrate holding means; A substrate heating device, further comprising: a torque cutoff unit that prevents rotation torque from being transmitted from the substrate holding unit to the temperature measurement unit by contacting the temperature measurement unit with the temperature measurement unit in a relative motionless manner.