JPH1131699A - Thermal treatment device and thermal treatment receptacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable maintaining the hermeticity of connecting parts, even if thermal treatment at a high temperature is performed. SOLUTION: A thermal treatment device 10 is provided with at least a heater 11, a hermetic thermal treatment receptacle 13 and a vacuum substitution chamber 15. The thermal treatment receptacle 13 and the vacuum substitution chamber 15 are connected via a connecting part 17. The thermal treatment receptacle 13 is provided with a transparent heater 13a and a non-transparent heating rays scattering part 13b. The heating rays scattering part 13b is formed on the side of the thermal treatment receptacle to be connected to the vacuum substitution chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a heat treatment apparatus, and more particularly to the structure of a heat treatment vessel suitable for use as a furnace core tube.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor device, various heat treatments such as an annealing treatment for activating the implanted ions and a surface oxidation are performed after the ion implantation. For example, 80
0 to 1000 ° C., which is a treatment at a considerably high temperature. The apparatus for performing such a heat treatment is required to have a structure that can be vacuum-substituted in order to purify the atmosphere gas in the apparatus and to prevent impurities from being mixed into an object to be processed.
A heat treatment apparatus having such a structure is also being used. FIG. 2 shows a main part of a heat treatment apparatus capable of vacuum replacement. FIG. 2 (A) is a diagram schematically showing a central portion of a furnace body of the apparatus, which is shown by a cross-section. The heat treatment apparatus 50 includes a heat treatment vessel 51 which is usually made of transparent quartz.
Is located between the furnace core tube, the vacuum replacement chamber 53, and the core tube 51 and the vacuum replacement chamber 53, and shuts off or opens the atmosphere in the furnace core tube 51 and the atmosphere in the vacuum replacement chamber 53. Connecting section 52 including an air lock valve 55 (also referred to as a gate valve or a vacuum valve) for
7 are provided. The vacuum replacement chamber 53 is provided with a first connection port 59 for evacuation, and the furnace core tube is provided with a second connection port 61 for introducing and discharging gas. FIG. 2B is a schematic enlarged view showing the periphery of a connection portion 52 between the furnace core tube 51 and the vacuum replacement chamber 53, and is shown by a cut section. Referring to FIG. 2 (B), a portion that needs to be hermetically sealed, for example, between the furnace core tube 51 and an air lock valve 55 (hereinafter, also simply referred to as a valve), or between the valve 55 and the vacuum replacement chamber 53. An O-ring 63 is provided in the middle or the like. This O-ring 63 is made of resin here,
It is attached to the valve 55 in advance.

The heat treatment is performed as follows. First,
After an object to be subjected to heat treatment (such as a semiconductor substrate) is installed in the vacuum replacement chamber 53, the inside of the vacuum replacement chamber 53 is evacuated. Thereafter, the air lock valve 55 is opened and the object to be processed is moved to the center of the furnace core tube 51 and installed. Thereafter, the object to be processed is heated by the heater 57 through the furnace core tube 51.

[0004]

By such a heat treatment, the heated furnace core tube 51 has a high temperature and emits heat rays. The heat rays are emitted in all directions, and some of the heat rays enter the inside of the wall of the furnace core tube 51 and propagate through the furnace core tube 51. Since the furnace core tube 51 is made of quartz having a high refractive index, the heat rays entering the inside of the wall are propagated by repeating total reflection, and are provided between the furnace core tube 51 and the valve 55. It reaches the vicinity of the ring 63 (FIG. 2B). O-ring 6
No. 3 is made of resin, and even if an O-ring made of Viton, which is excellent in heat resistance, cannot withstand heat exceeding 200 ° C., it shrinks or deforms and becomes airtight. I will lose. Further, even within the allowable temperature range, the life of the O-ring is shortened by long-time heating. Further, even if the distance between the heater 57 and the O-ring 63 is as large as possible, the O-ring 63 is directly heated by the heat rays confined in the quartz of the furnace core tube 51 and propagated. Even if the periphery of the O-ring 63 is cooled with water or the like, the cooling effect is difficult to reach because the O-ring 63 made of resin and the furnace core tube 51 made of quartz have very low thermal conductivity. As described above, in the heat treatment apparatus 50, the connection portion 52 between the furnace core tube 51 having a high temperature and the airlock valve 55 having a lower temperature than the furnace core tube 51 is airtight because the cooling thereof is insufficient. The O-ring 63 for connection to the battery is degraded by heat, loses its airtightness, and loses long-term reliability. As a result, there have been problems such as insufficient heat treatment, inferior product quality, and frequent replacement of the O-ring.

[0005] For this reason, in a heat treatment apparatus using an O-ring at the connection portion, it has been desired to develop a heat treatment device capable of maintaining the airtightness of the connection portion even when a high-temperature heat treatment is performed.

The inventors have conducted various researches and experiments. As a result, if the O-ring side portion of the heat treatment vessel such as a furnace tube is made of a material that does not easily transmit heat rays, the O-ring deteriorates. It has been found that this can be avoided, and the present invention has been achieved.

[0007]

Therefore, according to the present invention, at least a heater, a heat treatment container capable of hermetically sealing, and a vacuum replacement chamber are provided, and the heat treatment container and the vacuum replacement chamber are connected via a connecting portion. In the heat treatment apparatus, the heat treatment vessel includes a transparent heating section and an opaque heat ray scattering section formed continuously with the heating section, and the side of the heat treatment vessel connected to the vacuum replacement chamber is heated by a heat ray. It is characterized by being formed by a scattering portion.

When the heating part of the heat treatment apparatus is heated by the heater, heat rays are radiated from the heating part, and a part of the heat rays enters the wall of the heat treatment vessel and propagates while repeating total reflection. However, the propagating heat rays are scattered when they reach the opaque heat ray scattering section from the transparent heating section. Therefore, the heat ray does not propagate beyond the heat ray scattering part. Therefore, the heat does not reach the connection between the heat treatment vessel and the vacuum replacement chamber. For example, when a resin O-ring or the like is used to make the connection airtight, the heat may deteriorate the O-ring. It disappears and the airtightness of the connection can be maintained.

Preferably, the heating section and the heat ray scattering section are made of quartz, and the heating section and the heat ray scattering section are welded.

[0010] By using quartz as the material of the heating section and the heat ray scattering section, that is, the material of the heat treatment container, it is possible to prevent heat from reaching the connection section by heat conduction because quartz is a material having a relatively low thermal conductivity. Can be. Further, since the transparent heating portion and the opaque heat ray scattering portion can be easily welded, the forming process is also simplified.

[0011] Preferably, the heat ray scattering portion is formed by mixing bubbles in quartz.

Since the opaque heat ray scattering portion is formed by mixing bubbles in quartz, the inside of the wall of the heat ray scattering portion can be made opaque. The degree of the opacity is preferably such that the inside of the heat ray scattering portion having a thickness of 3 mm cannot be seen through the wall when viewed from the outside.
Thus, the heat rays that enter the heating section made of transparent quartz and propagate therethrough can be scattered by the heat ray scattering section made of opaque quartz containing bubbles.

It is preferable that the connecting portion includes an O-ring.

In a heat treatment apparatus having a structure in which an O-ring is included in a connection portion between the heat treatment vessel and the vacuum replacement chamber, heat rays propagating from the heat treatment vessel are scattered by the heat-ray scattering section so as to be scattered by the O-ring. Does not reach the heat. Therefore, even if a resinous O-ring is used, the O-ring is not likely to be degraded by heat. Further, as a heat treatment container that can be used without being limited to a heat treatment apparatus, the heat treatment container of the present invention has a transparent one end side. And a non-transparent heat-ray scattering portion at the other end formed continuously with the heating portion.

In the case where heat is applied to only one end of the container and the influence of heat is not desired to be applied to the other end, for example, a member which is deteriorated by heat is provided at the other end. When one end is heated, the other end scatters heat rays by making one end side of the heat treatment container a transparent heating section and the other end side opaque to form a heat ray scattering section. There is no possibility that heat reaches the member provided on the end side.

Preferably, the heating section and the heat ray scattering section are made of quartz, and the heating section and the heat ray scattering section are welded to each other. Air bubbles are mixed in the heat ray scattering section with quartz. It is good to be formed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that the drawings merely schematically show the sizes, shapes, and arrangements of the components so that the invention can be understood, and therefore, the invention is not limited to the illustrated examples. In the drawings, hatching (hatched lines) showing a cross section is omitted except for a part for easy understanding of the drawings.

<Embodiment> As an embodiment, at least a heater, a heat treatment container capable of hermetically sealing,
A heat treatment apparatus having a vacuum replacement chamber and in which the heat treatment container and the vacuum replacement chamber are connected via a connection portion will be described with reference to FIG. FIG. 1A is a diagram schematically showing a heat treatment apparatus according to this embodiment, which is indicated by a cross section. FIG. 1B is an enlarged view schematically showing a connection portion between the heat treatment vessel and the vacuum replacement chamber of the heat treatment apparatus. This is also shown by a cut in section. FIG. 1C is a further enlarged view of an area A surrounded by a dotted line in FIG.

The heat treatment apparatus 10 includes a heater 11, a furnace tube as a heat treatment vessel 13, a vacuum replacement chamber 15, and an air lock valve 17a and an O-ring 17b as a connection 17 (FIG. 1). (A) and FIG. 1 (B)). The furnace core tube 13 has a heating part 13a made of transparent quartz and a heat ray scattering part 13b made of opaque quartz.
And the heating unit 13a and the heat ray scattering unit 13b
Are connected by welding to constitute one furnace core tube 13. In addition, the heat ray scattering portion 13b is made of quartz which is made opaque by including bubbles. Here, the thickness of the wall of the furnace core tube 13 is 3 mm, and the opacity is such that the inside cannot be seen at all through the wall when the heat ray scattering portion 13b is viewed from the outside. Thus, the heat-ray scattering portion 13b can have a structure in which the surface and the inside of the wall are not opaque and the inside and the inside are opaque, as in the case of frosted glass (see FIG. 1 (A)). )).

In the heat treatment apparatus 10, the furnace core tube 13 has a heat ray scattering portion 13b side airtightly connected to an air lock valve 17a via an O-ring 17b, and the opposite side of the air lock valve and a vacuum replacement chamber are also provided. Similarly, another O-ring 17
b (see FIG. 1B). The heating unit 1 is heated so as to heat the heating unit 13a of the furnace core tube 13.
A heater 11 is provided outside 3a. A first connection port 19 for evacuating the vacuum is formed in the vacuum replacement chamber 15, and a second connection port 21 for introducing and discharging gas into and from the furnace core tube 13 is provided.

In the heat treatment, first, an object to be subjected to a heat treatment (such as a semiconductor substrate) is set in the vacuum replacement chamber 15, and then the inside of the vacuum replacement chamber 15 is evacuated. Thereafter, the air lock valve 17a is opened and the object to be processed is heated by the heating unit 13
Move to a. Thereafter, the object to be processed is heated by the heater 11 via the furnace core tube 13.

Here, FIG. 1C is referred to. Arrow B in the figure represents a heat ray. The heating unit 13a heated to a high temperature emits heat rays. Then, a part of the heat ray enters the inside of the wall of the furnace core tube 13 and propagates through the transparent quartz with repeated total reflection. The heat ray scatters when it reaches the opaque heat ray scattering part 13b including bubbles. Therefore, the heat ray does not substantially reach the O-ring 17a in contact with the heat ray scattering section 13b (FIG. 1C). Further, since the furnace core tube 13 is formed using quartz, the thermal conductivity is low. As a result, the heat generated by the heat treatment is reduced to O
There is no danger of reaching the ring 17b, and even if an O-ring made of resin is used, deterioration due to heat can be prevented.

Further, the portion of the second connection port 21 of the furnace core tube 13 may be formed using opaque quartz. Second connection port 2
This is because there may be a member such as an O-ring for which an adverse effect due to heating must be avoided depending on the member connected to the first member.

[0024]

As is clear from the above description, in the heat treatment apparatus of the present invention, the heat treatment container has a transparent heating section and an opaque heat ray scattering section formed continuously with the heating section. The side of the heat treatment container connected to the vacuum replacement chamber is formed by a heat ray scattering part. For this reason, even if the heat ray radiated by heating the heating unit enters the inside of the container wall and propagates, the heat ray scattering unit can scatter the heat ray propagating from the heating unit. It does not propagate to the connection with the replacement chamber. Therefore, even if an O-ring made of, for example, resin is used for the connecting portion, there is no possibility that the O-ring is deteriorated by heat. Therefore, no matter how high the temperature of the heat treatment, the airtightness of the connection portion can be maintained. That is, the airtightness of the entire heat treatment apparatus can be maintained, and the heat treatment can be stably performed. Also,
Since the number of times of replacing the O-ring is reduced, the work can be rationalized.

Further, such a heat treatment vessel is not limited to use in a heat treatment apparatus, but may be used in a vessel that receives heat from a certain environment or a joint between a vessel that generates heat and another member. When it is necessary to avoid an increase in the temperature of the joined portion or other members joined due to propagation of the heat, it is suitable for use in the container.

[Brief description of the drawings]

FIG. 1A is a schematic cross-sectional view of a heat treatment apparatus according to an embodiment, FIG. 1B is a schematic cross-sectional view around a connection portion, and FIG. FIG. 3 is a schematic enlarged view of a part of the diagram shown in FIG.

FIG. 2A is a schematic cross-sectional view of a conventional heat treatment apparatus, and FIG. 2B is a schematic cross-sectional view around a connection portion.

[Explanation of symbols]

 10, 50: Heat treatment apparatus 11, 57: Heater 13, 51: Heat treatment vessel, furnace core tube 13a: Heating unit 13b: Heat ray scattering unit 15, 53: Vacuum replacement chamber 17, 52: Connection unit 17a, 55: Air lock Valve, valve 17b, 63: O-ring 19, 59: first connection port 21, 61: second connection port

Claims (7)

[Claims] 1. A heat treatment apparatus comprising at least a heater, a heat treatment container capable of hermetically sealing, and a vacuum replacement chamber, wherein the heat treatment container and the vacuum replacement chamber are connected via a connection portion. The heat treatment container includes a transparent heating unit and an opaque heat ray scattering unit formed continuously with the heating unit, and a side of the heat treatment container connected to the vacuum replacement chamber is formed by the heat ray scattering unit. A heat treatment apparatus, comprising: 2. The heat treatment apparatus according to claim 1, wherein the heating section and the heat ray scattering section are made of quartz, and the heating section and the heat ray scattering section are welded. Heat treatment equipment. 3. The heat treatment apparatus according to claim 2, wherein the heat ray scattering portion is formed by mixing bubbles in the quartz. 4. The heat treatment apparatus according to claim 1, wherein the connection portion includes an O-ring. 5. A heat treatment container capable of hermetically sealing, comprising: a transparent heating section on one end side; and an opaque heat ray scattering section on the other end side formed continuously with the heating section. 6. The heat treatment container according to claim 5, wherein the heating portion and the heat ray scattering portion are formed of quartz, and the heating portion and the heat ray scattering portion are welded. Heat treatment container. 7. The heat treatment container according to claim 6, wherein the heat ray scattering portion is formed by mixing bubbles in the quartz.