JP2016109318A - Light collection mirror type heating furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that in a conventional light collection mirror type heating furnace, it is difficult to attain both of cooling efficiency and downsizing of a device.SOLUTION: In a light collection mirror type heating furnace, light radiated from a light source is reflected by a reflection mirror to irradiate a heated object, and thereby the heated object is heated. The light source, and the reflection mirror and the heated object are sectioned by a wall having a window member having infrared permeability to be positioned to independently individual chambers. Light radiated to a heated object surface penetrates the window member having infrared permeability to irradiate the heated object.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heating furnace for use in material processing and the like, and relates to a condenser mirror heating furnace for heating with infrared rays.

As described in Patent Documents 1 to 3, as an apparatus for manufacturing a single crystal, heating is performed by collecting infrared rays toward a target sintered body such as aluminum oxide and a seed crystal. A condensing mirror type heating furnace is known.
Such a condensing mirror type heating furnace has a sintered body such as aluminum oxide and a seed crystal placed on a stage moving in the vertical direction, and a reflecting mirror made of a spheroid at a position surrounding the seed crystal in the horizontal direction. A light source such as a halogen lamp is installed at one focal point of the spheroid, and the sintered body and seed crystal are positioned at the other focal point of the spheroid.
Then, the infrared rays emitted from the light source are condensed and heated so as to focus on the sintered body and the seed crystal directly or through the reflecting surface of the reflecting mirror. It is a condenser mirror heating furnace that grows a single crystal by lowering.

Further, as described in Patent Document 4, a heated object base is placed at one focal point of a reflecting surface whose inner surface is a spheroidal surface, and a heater installed in the reflecting surface is used as a surface light source for radiation. It is known to heat an object to be heated on the object to be heated by reflecting the infrared ray directly and to the ellipsoidal surface.
Further, as described in Patent Document 5, as a heating furnace used for manufacturing a semiconductor, a resistance heating type furnace is known in which a silicon wafer is placed on a quartz board and heated from the quartz board. However, even if the heat source is infrared, a quartz board is inserted into the furnace, so the size of the furnace is large enough to heat a wafer larger than the wafer. Since it takes a long time to raise the temperature, one heating process cannot be performed in a short time.
Furthermore, when heating the wafer surface, a surface formed by installing a plurality of infrared lamps at a position vertically above the wafer facing the mounted wafer surface for the purpose of irradiating a range that can sufficiently cover the diameter of the wafer. There has also been known a heat treatment apparatus which is provided so as to be parallel to the wafer surface and heats the wafer surface by such an apparatus.

Further, Patent Document 6 discloses an apparatus that heats an object to be heated by providing a heater at the first focal point of the elliptical reflector and a heated object at the second focal point. A device that heats a heated object by reflecting the emitted infrared light by a reflecting mirror and irradiating the heated object is disclosed in Patent Document 8 in which infrared light is irradiated by a heater head composed of an infrared lamp and an elliptical mirror. Devices for heating the mounted parts are described respectively.
Further, Patent Document 9 describes a light heating apparatus in which the size of an effective light emitting region, which is a region where a flash lamp is disposed, is larger than that of a wafer.

JP 2007-145611 A Japanese Patent No. 3668738 WO2005 / 075713 JP 2008-107050 A JP 2000-223488 A JP-A-2005-294243 Japanese Patent Laid-Open No. 10-82589 Japanese Patent Laid-Open No. 5-205852 JP 2006-325441 A

In the conventional condensing mirror type heating furnace, an infrared light source is provided at one focal point of a concave surface, which is an elliptical mirror, the object to be heated is reflected from the light source to the concave surface and directly installed at the other focal point. Or it heats from the side.
In addition, as in the inventions described in Patent Documents 1 to 3, a structure in which a light source is provided at one focal point of the cut spheroid and a heated object is disposed at the other focal point is a common focal point. A circle formed from one focal point is formed around the heated object.
In the case of such a structure, heating is performed exclusively from 360 ° in the lateral direction with respect to the planar object to be heated. Therefore, when the object to be heated is installed horizontally, infrared rays are irradiated on the peripheral surface of the object to be heated. However, the amount of heat absorbed with respect to the plane is reduced. Even if the object to be heated is installed vertically or obliquely, both surfaces of the object to be heated are exclusively heated, and a specific one surface cannot be heated with high efficiency.

As a result, devices other than the object to be heated are also heated to a high temperature, so that an air cooling or water cooling cooling system for cooling the device becomes larger, resulting in energy and air required for cooling. And the facilities for supplying water must be enlarged. In particular, when air is flowed to cool the heating source, even if air flows in a relatively large volume space surrounded by a spheroid, a part of that air can directly touch the heating source and cool it. Therefore, efficient cooling was difficult.
Further, in the structure in which the object to be heated is installed in a place sandwiched between the ellipsoidal mirrors, in addition to the large equipment required for the cooling described above, the ellipsoidal mirror that is considerably larger than the size of the object to be heated is used. Therefore, there was a limit to downsizing the device.

According to the heating device in which a plurality of infrared lamps are installed vertically above the wafer, facing the surface of the mounted wafer or the like, the wafer can be heated relatively uniformly. Gas supply means to be provided above the wafer for supplying gas to the surface for processing cannot be provided opposite to the wafer surface without inhibiting infrared irradiation.
Moreover, in order to heat uniformly, it was necessary to make the installation surface of the infrared lamp larger than the object to be heated. For this reason, in particular, most of the energy radiated from the infrared lamp installed at the peripheral portion of the heating device is not irradiated to the object to be heated, and the members around the object to be heated are also heated. In addition, the heating of the object to be heated affects not only the radiation from the infrared lamp but also the heating by conduction from the heated peripheral member, so that the heating temperature of the object to be heated is controlled. Becomes difficult. Furthermore, in order to perform control more accurately, it is necessary to enlarge the internal space of the heating furnace, and as a result, the entire heating furnace becomes larger than necessary.
Further, if the unit comprising the infrared lamp and the reflector and the object to be heated are provided in one space, the object to be heated will be installed in a larger space, and the contamination by the fine particles in the space will be increased accordingly. When it is necessary to heat in a specific atmosphere, a large amount of gas is required. In addition, since it is necessary to cool the unit and, on the contrary, the object to be heated needs to be heated quickly, the temperature control that contradicts the unit and the object to be heated may be required.
In order to reduce the size of the reflecting mirror, it is sometimes required to make the reflecting mirror smaller in curvature or to arrange an infrared lamp in the immediate vicinity of the reflecting mirror surface.
Further, in the means for making the light emitting area larger than the wafer, it is considered that the larger the light emitting area is, and the farther the light emitting area is from the wafer, the more uniformly the wafer can be heated. Since the size is increased and necessary power and cooling capacity are increased, efficient heating cannot be performed.

1. A condenser mirror type heating furnace for heating the object to be heated by reflecting the light emitted from the light source with a reflecting mirror and irradiating the object to be heated,
The light source, the reflector and the object to be heated are located in separate and separate chambers separated by a wall having an infrared transparent window member;
A condensing mirror type heating furnace in which light irradiated on the surface of an object to be heated is transmitted to the window member that is transparent to infrared rays and irradiated on the object to be heated.
2. 2. The condensing mirror type heating furnace according to 1, wherein the reflecting mirror is a concave mirror, and the diameter of the surface facing the reflecting mirror in the space for storing the object to be heated during heating is larger than the diameter of the opening. .
3. 3. The condensing mirror type heating furnace according to 1 or 2, wherein a hole is provided near the light source mounting portion of the reflecting mirror, and cooling air is supplied from the hole into the reflecting mirror.
4). The condensing according to any one of 1 to 3, wherein a hole is provided in the bottom of the reflecting mirror farthest from the object to be heated, a hood surrounding the reflecting mirror is provided, and an exhaust device is provided in the hood to cool the reflecting mirror and the light source. Mirror heating furnace.
5. 5. The condensing mirror heating furnace according to any one of 1 to 4, wherein the infrared transmissive window member functions as a concave lens or a convex lens.
6). 6. The condensing mirror type heating furnace according to any one of 1 to 5, wherein an infrared focal point formed by reflection is not located on the surface of the object to be heated.
7). The condensing mirror system heating furnace in any one of 1-6 which provides another reflecting mirror on both sides of a to-be-heated material with respect to the said reflecting mirror.
8). The reflecting mirror is a condensing mirror heating furnace according to any one of 1 to 7, in which a glass material is used as a substrate and an infrared reflecting layer is provided on an inner surface thereof.
9. The condensing mirror type heating furnace according to any one of 1 to 8, wherein a lens made of an infrared transmitting material is provided at an opening of the reflecting mirror.
10. The condensing mirror system heating furnace in any one of 1-9 which provided the gas jet nozzle facing the to-be-heated material surface so that the to-be-heated material surface might become a specific atmosphere.
11. The light source and the reflecting mirror are provided in a room where the window facing the opening of the reflecting mirror is infrared transmissive, and the object to be heated is placed in a room whose surface on the light source and reflecting mirror side is an infrared transmissive window member. The condensing mirror system heating furnace in any one of 1-10 provided.
12 Between the window of the chamber provided with the light source and the reflector and the window of the chamber provided with the object to be heated, a gas flow path is provided between the two infrared transmissive window members. 12. The condensing mirror heating furnace according to 11, wherein a gas jet opening communicating with the gas flow path is provided in an indoor window member provided with the object to be heated.
13. The chamber provided with the article to be heated is the condensing mirror type heating furnace according to any one of 1 to 12, wherein the entire surface is made of quartz.
14 The condensing mirror type heating furnace according to any one of 1 to 13, which is for an object to be heated having a diameter of 50 mm or less.

The condenser mirror type heating furnace of the present invention is provided with a light source and a reflecting mirror, reflects light emitted from the light source to the reflecting mirror, and finally irradiates the surface of the object to be heated from a vertical direction. Is based on a condenser mirror type heating furnace for heating an object to be heated.
At this time, the chamber in which the light source and the reflecting mirror are provided and the chamber in which the object to be heated are arranged are separate chambers that are independent and do not communicate with each other. For this reason, when the object to be heated is taken in and out of the condenser mirror type heating furnace, the light source and the reflecting mirror are not exposed to the outside air. In addition, since the object to be heated is also separated from the room where the light source and the condenser mirror are located, the heat treatment can be performed in a cleaner environment, and when heating in a specific atmosphere, It is not necessary to place the light source and the reflecting mirror in the atmosphere, and the atmosphere can be realized with a smaller amount of gas.
During heating, not only the object to be heated but also the condenser mirror is heated. When a cooling gas is circulated to cool the condenser mirror, the object to be heated is simultaneously cooled. There is no gas circulation. Therefore, the object to be heated can be heated in any atmosphere including under vacuum.

  In addition, the present invention reflects the infrared rays generated from the light source on the conventional spheroid and does not have a structure of a device for heating from the side around the object to be heated. There is no device for heating on the side of. As a result, the state of the object to be heated can be confirmed from the side of the apparatus, and the operating status of the CVD furnace and the single crystal growing apparatus can be grasped even during heating.

Furthermore, the infrared transmissive window member can be a flat plate member, but can also be provided with a concave surface and / or a convex surface. In that case, it functions as a concave lens or a convex lens, On the other hand, it is possible to irradiate with more appropriate infrared intensity and distribution. Moreover, in order to reduce the size of the reflecting mirror, it is required to make the reflecting mirror smaller in curvature or to place an infrared lamp in the immediate vicinity of the reflecting mirror surface. However, by providing a concave lens or a convex lens, It becomes possible to increase the curvature or to provide an infrared lamp away from the reflecting mirror surface. As a result, the light emitted from the infrared lamp can be used effectively for heating, and the infrared lamp can have a smaller output.
And it is possible to uniformly heat a particularly required portion of the surface of the object to be heated, and it is also possible to irradiate the surface of the object to be heated more uniformly without focusing the light. .

  When the object to be heated is small and the apparatus is downsized accordingly, the output of the infrared lamp can be reduced, and the size of the reflecting mirror is also reduced. However, if the energy required for heating the object to be heated itself does not change, the density of energy received by the object to be heated itself does not change or rather increases.

The surface to be heated may be formed and installed such that the surface to be heated is horizontal, but the surface to be heated of the object to be heated may be placed in a non-horizontal state.
In this heating furnace, a light source for heating is positioned above the object to be heated and the surface of the object to be heated is heated from above, so that a large space can be formed on the side of the object to be heated. For this reason, it is possible to provide a measuring means such as temperature or a control means on the side, and to flow a cooling gas. In addition, it is possible to effectively utilize the space around the object to be heated by installing means for transferring the object to be heated in the space provided on the side, and the object to be heated is introduced into the apparatus. A series of operations from the stage to the stage of taking it out of the apparatus can be performed more efficiently.
For example, when a CVD furnace is used, a gas can be applied from the side surface of the object to be heated to be processed by CVD, and a high-quality thin film can be formed by CVD on the heated object to be heated. it can.

In addition to the uniform heating of the object to be heated by such a mechanism, the light source usually emits light by heating the filament, and the filament is not completely a point light source. It can be seen that the mirror focus may or may not be strictly focused.
When light is irradiated in a so-called defocused state that is not focused, the image of the filament is not formed on the object to be heated. If it does so, the irradiation unevenness of the light which reflected the shape of the filament on the to-be-heated object will not arise, and also in this point, it becomes possible to heat the to-be-heated object surface more uniformly.
For example, when a spheroid is used as a reflecting mirror and a light source is placed at one focal point, the infrared ray generated from the light source is focused on the other focal point, but the object to be heated is the other focal point. Without putting it in the position, put it in another position where the focus has been removed. Thereby, the surface of the object to be heated is more uniformly irradiated with infrared rays, and as a result, the surface is heated uniformly.
In addition, by installing a concave lens or a member having a convex lens function between the reflecting mirror and the object to be heated, and adjusting the position of the focal point of the infrared rays or not focusing, Similarly, infrared rays can be uniformly irradiated on the surface of the object to be heated.

  According to the present invention, the object to be heated is heated uniformly, and the light source exists above the object to be heated. Therefore, a space can be provided on the side and the lower side of the object to be heated. Thus, operations such as introduction of gas, arrangement and operation of processing / moving jigs, movement of an object to be heated, detection and control of temperature / gas supply amount, and the like can be performed.

  Furthermore, it is not necessary to rotate the object to be heated such as a wafer, and even if a gas (main gas, support gas) is applied to the wafer to be heated in the room where the object to be heated is provided, Since only the object to be heated is heated, deposits on the inner wall of the quartz tube due to gas decomposition can be reduced.

  In addition, since less energy is used and less energy is consumed for heating the reflecting surface or the like, the cooling system can be made smaller and the entire apparatus can be made smaller. Moreover, according to the condenser mirror heating furnace of the present invention, the light source is installed in a relatively narrow space in the annular reflecting surface. However, when air is introduced into the annular reflecting surface, the light source is efficiently brought into contact with the air. Can be cooled.

  Note that an infrared lamp can be used as the light source, and infrared light can be used as the light. However, the light is not limited to infrared light, and may be any light that heats the object to be heated by irradiating the object to be heated. Good. Further, the light source for emitting such light is not limited to the infrared lamp.

Schematic of the condenser mirror type heating furnace of the present invention Outline of the condenser mirror type heating furnace of the present invention Detailed view of the condenser mirror type heating furnace of the present invention Detailed view of the condenser mirror type heating furnace of the present invention Detailed view of the condenser mirror type heating furnace of the present invention Partial enlarged view of the condenser mirror type heating furnace of the present invention

Hereinafter, the present invention will be described with reference to the drawings in the case where the light source is an infrared lamp and the light is infrared. Even when other light sources or other lights are employed, the structure of the present invention can be employed.
Depending on the physical properties and materials of the object to be heated, there are those that can be heated by light other than infrared rays. In this case, the light used in the present invention includes light other than infrared rays.

<Condenser mirror heating furnace>
The condenser mirror type heating furnace of the present invention includes a light source that emits energy for heating such as infrared rays, and a reflecting mirror that reflects infrared rays emitted from the light sources and irradiates infrared rays toward an object to be heated. , And an object to be heated, which is isolated from the reflecting mirror and the light source so as not to communicate with each other and includes an infrared transmissive window member for transmitting infrared rays.
The object to be heated to be heated by the condensing mirror type heating furnace of the present invention is an object that is processed by normal heating such as glass, semiconductor material, metal, ceramic, resin and the like. It can also be used for a part of manufacturing processes such as LSI and MEMS.
Specifically, it can be used as an apparatus involving heating, such as a vapor deposition apparatus, a CVD furnace, or a single crystal manufacturing apparatus.

(light source)
The light source used in the present invention needs to be able to generate infrared rays to the extent that it can be used for heating, and is a known light source depending on the size of the object to be heated, the reflecting mirror, and the target heating temperature. The type of the light source can be determined as appropriate from the above. An infrared lamp is generally used as the lamp, but is not limited thereto, and a light source that can be used in a heating furnace that performs heating with light can be arbitrarily used.

(Reflector)
The reflecting mirror used in the present invention may be made of a known material, and has a structure that occupies a known reflectivity, such as a metal substrate itself or a metal substrate provided with another metal layer as a reflecting surface. Can be adopted. In addition, a reflective mirror can be obtained by forming a known infrared reflective film on a glassy reflective mirror substrate.
Further, it may be manufactured by a manufacturing method such as cutting out from a block of metal or the like, but it may be manufactured by dividing the block into a plurality of blocks and assembling these blocks.
The reflecting mirror is a concave reflecting mirror having a spheroid shape on the inner surface, and a light source can be arranged at one focal point, but other than a spheroid shape such as a rotating paraboloid or a spherical surface. The shape of the light source may be determined, and the arrangement of the light sources can be arbitrarily determined.
For example, in the case of a spherical mirror, since the focal point is not focused on the surface of the object to be heated provided at a position different from the light source at any position, it is more uniform than when there is a focal point. The object to be heated can be heated.
The size of the reflecting mirror is selected depending on the size of the object to be heated. However, heating is performed with the object to be heated placed on the stage, and a sufficient amount is stored in the chamber containing the object to be heated. Since it is necessary to heat in a gaseous atmosphere, it is preferable that the surface on the reflecting mirror side of the chamber containing the object to be heated is larger than the opening of the concave reflecting mirror.

(Subject to be heated)
An object to be heated to be processed in the condensing mirror type heating furnace in the present invention is a thing that requires a heating process of a semiconductor element, a wafer, or the like.
Although the size of the object to be heated is determined to some extent depending on its use, in the present invention, an object to be heated of an arbitrary size can be processed. However, the diameter is preferably 50 mm or less, more preferably 30 mm or less, and particularly preferably 15 mm or less.
And as a shape of a to-be-heated object, the surface to which light is irradiated should just be a plane, and the plane which is not a plane in the range which does not deviate from the objective of this invention may be sufficient.
According to the condenser mirror type heating furnace of the present invention, the temperature of the object to be heated can be heated to 1300 ° C. or more after a few seconds from the start of heating, and the rate of heat treatment of the object to be heated can be improved. .
The chamber in which the object to be heated is placed needs to be formed of an infrared transparent material on the reflecting mirror side surface. When the material is formed of an infrared transmitting material, the material serves as a window portion to transmit infrared light irradiated from the reflecting mirror, and the object to be heated can be irradiated with infrared light.
Further, considering that the surface of the object to be heated is treated in a specific atmosphere, when the atmosphere has a property such as particularly high reactivity, for example, a material other than the infrared transmitting material is to be heated. If it is used even in a part of the chamber in which the material is disposed, the material may cause corrosion or the like. At this time, all the materials constituting the room are required to have heat resistance and corrosion resistance, and the room is preferably made of quartz. When quartz or the like is used, it is difficult to join quartz or the like by bonding, welding, or the like, and therefore, members made of quartz can be joined together by, for example, a sealing member such as an O-ring while the joining portion is hermetically sealed. . Furthermore, when using the O-ring, it is necessary to sufficiently separate the portion where the O-ring is used from the optical path of the infrared so that the O-ring itself does not hit the infrared rays and cause deterioration.

The structure of the condensing mirror type heating furnace of the present invention will be described below with reference to the drawings.
FIG. 1A shows a main part of a condenser mirror type heating furnace of the present invention, in which infrared rays emitted from a light source 1 are reflected by a surrounding reflecting mirror 2 and directed toward an object to be heated 4 located therebelow. Irradiate.
Here, the space 3 in which the unit including the light source 1 and the reflecting mirror 2 is installed and the space 5 in which the object to be heated 4 are installed are separated from each other by dividing the space by the wall 6. They do not communicate and form independent chambers.

In FIG. 1A, a window member 7 is provided on the wall 6. For this reason, even if the spaces 3 and 5 are independent, the infrared rays for heating the article to be heated 4 are irradiated through the window member 7. Here, the window member 7 is a material that transmits infrared rays, and quartz or the like can be used.
The object to be heated is placed on the stage 8 and is accurately placed at a predetermined position for heating, and is placed at that position at least during heating.
The stage 8 is supported by a support 9, and an object to be heated introduced from the outside of the heating furnace is optionally transferred by a transfer means such as an arm provided in a space sealed with respect to the outside of the heating furnace. It passes by opening and closing the chamber and is placed on the stage inside the heating furnace.
Further, if necessary, the support 9 is positioned in the vertical and horizontal directions.

  Further, as shown in the figure, during heating, for example, by rotating the support, the object to be heated can be rotated about the axis that coincides with the optical axis of the infrared rays. At this time, the center of the heated surface of the object to be heated may coincide with the rotation axis, or for the purpose of heating the object to be heated more uniformly, the center of the heated surface and the rotation axis do not coincide with each other. You may rotate using the axis | shaft which eccentrically heated the thing as a rotating shaft. Further, the rotating shaft itself can be rotated using a planetary gear or the like.

In addition, instead of moving the object to be heated up and down by the support as described above and installing it at the position during heating, the object to be heated is moved only from one of the left and right directions to the horizontal direction in FIG. 1A. Thus, it is possible to place the object to be heated from the heating furnace by placing it in the heating position and moving it in the left-right direction after heating.
Moreover, the infrared irradiation intensity | strength etc. to a to-be-heated material can be adjusted by moving an infrared lamp and a reflecting mirror up and down integrally.

In the present invention, when operating the condensing mirror type heating furnace, it is necessary to cool the light source and the reflecting mirror in some cases.
As a cooling method, it is possible to adopt two types of cooling, such as air cooling with a gas such as air, and water cooling with a liquid such as water, or a means using both of them.
For example, as air cooling, means for injecting air from one or more of the nozzles N to the light source and the reflecting mirror, as water cooling, although not shown, a jacket that circulates water or the like on the back side that is not the reflecting surface of the reflecting mirror, It is possible to employ means for providing a flow path or the like and cooling from the back side of the condenser mirror.

Further, a hole 11 is provided in the vicinity of the light source mounting portion of the reflecting mirror, a fan is provided in the hole 11, or an air supply pipe from the fan is connected to the hole, and air is supplied into the reflecting mirror to supply the reflecting mirror and the light source. Can be cooled.
Furthermore, a hole is provided at the bottom of the reflecting mirror, that is, where the extension line connecting the object to be heated and the light source intersects the reflecting mirror, and the gas flow generated by an exhaust device such as a fan provided outside the reflecting mirror By forming from the opening toward the hole, the inner and outer surfaces of the reflecting mirror and the light source can be cooled.
Among these means, rational means and cooling conditions can be adopted in consideration of the heating temperature by the condenser mirror type heating furnace, the operation interval, and the like.

In the present invention, the light source, the reflecting mirror, and the object to be heated are distinguished from each other by a wall having an infrared transmissive window member and are located in separate independent chambers. For this reason, a chamber for storing the light source and the reflecting mirror is provided, and at least a wall facing the object to be heated is provided with an infrared transmissive window. On the other hand, the chamber for storing the object to be heated includes at least a wall facing the light source and the reflecting mirror side by an infrared transmissive window.
When a gas for processing or the like flows from the heated surface side of the object to be heated toward the heated surface, a member constituting the gas flow path or an opening for flowing the gas toward the heated surface is configured. All the members to be made need to be composed of infrared transmissive members.
In addition, the atmosphere of the chamber having the light source and the reflecting mirror and the atmosphere having the object to be heated are completely independent, and these spaces do not communicate with each other. Even in the case of the lower side, both chambers can be operated in completely different atmospheres, for example, air is blown for cooling in the rear side or reflector side chamber.
When the heating source and reflector and the object to be heated are installed in one room, when the object to be heated is taken in and out, when the type of gas to be supplied is changed, when the room is evacuated, etc. The space to be changed, that is, the size of the chamber is large, so it takes a long time to change the condition, and it is necessary to enlarge the device more than necessary in all respects, such as the vacuum pump and the amount of atmospheric gas used. Arise.
However, according to the present invention, these points can be eliminated and the heating process can be performed more efficiently.

In addition to these, as shown in FIG. 1B, for example, air is sucked by a pipe connected by providing an air suction hole in the vicinity of the location where the light source is provided in the reflecting mirror. On the other hand, for example, by sealing the opening 10 of the reflecting mirror with an infrared transmitting material, and providing one or more air introduction holes obliquely in the opening of the reflecting mirror, and sucking air from the suction port, Air can be introduced from the introduction hole so as to form a swirling flow along the reflecting surface of the reflecting mirror.
In this case, the air introduced into the reflecting mirror efficiently cools the reflecting mirror, so that the force required for air suction can be kept to a minimum.

In the condenser mirror type heating furnace of FIG. 1C, a convex lens made of an infrared transmitting material is provided in the opening 10 of the reflecting mirror.
In this regard, when the object to be heated is irradiated with infrared rays by the condenser mirror heating furnace of the present invention, for example, the reflecting mirror is made of a spheroid, the light source is placed at one focus, and the other focus is covered. By providing a heated object, it is possible to focus on the surface of the object to be heated.
Further, depending on the positional relationship between the infrared lamp and the reflecting mirror, a concave lens can be provided in the opening 10 of the reflecting mirror instead of the above convex lens.

However, since the light source is usually composed of a light bulb provided with an internal coil, when the object to be heated has a focus, it means that an image of the coil appears on the surface of the object to be heated. In such a state, the surface of the object to be heated is never heated uniformly, and therefore it is required to employ a means for uniformly heating the surface of the object to be heated, for example.
Further, if the focal point is not positioned on the surface of the object to be heated, heating can be performed more uniformly.

The condenser mirror type heating furnace of FIG. 1C is an example in which a convex lens is provided in the opening 10 to perform correction so that infrared rays are evenly irradiated on the surface of the object to be heated. Of course, a spherical lens or an aspherical lens may be used, a concave lens may be adopted instead of the convex lens, and a Fresnel lens may be used. The lens used in this manner can be selected according to the position of the light source, the shape of the mirror, the distance to the surface of the object to be heated, and the like.
In the example of FIG. 1C, in order to provide a lens at the opening of the reflecting mirror, it is sometimes necessary to provide a structure for cooling with air as shown in FIG. 1B.

FIG. 1D is intended to correct in order to make the infrared irradiation intensity on the surface of the object to be heated more uniform as in FIG. 1C.
Although FIG. 1D shows an example in which the window member provided in the chamber for storing the object to be heated is a concave lens, it may be a convex lens as in FIG. 1C, and may be a spherical lens or an aspherical lens.

The example shown in FIG. 2 is an example based on A, B and D in FIG.
In FIG. 2A, a hood 21 is provided so as to cover the reflecting mirror 2, and fins are installed as exhaust devices in an opening provided on the upper surface of the hood 21. Try to drain. As a result, the bottom of the concave surface of the reflecting mirror 2, that is, the extension line connecting the object to be heated and the light source is a point where the reflecting mirror intersects, and through the hole provided in the position closest to the fin F, and the reflecting mirror 2 and the hood Air or the like is sucked from the outside of the reflecting mirror 2 and the hood 21 through the gap provided between the two.
Then, a flow that flows along the inner surface and the outer surface of the reflecting mirror 2 and a flow that flows around the light source 1 are generated. By such a flow, the reflecting mirror 2 and the light source 1 are cooled.
Further, when the specific gas is circulated in the space 5 in order to place the heated object 4 in a specific atmosphere, for example, the gas is formed on the wall that divides the space 5 so as to circulate the upper surface of the heated object 4. The gas g can be supplied and discharged by providing an inflow hole and an outflow hole.

The example shown in B of FIG. 2 is an example relating to an apparatus when the object to be heated 4 is conveyed from outside the apparatus, processed under heating conditions, and the processed object to be heated 4 is conveyed outside the apparatus.
The stage 8 on which the object to be heated 4 is placed has a structure that moves up and down together with the support 9, and the object to be heated 4 is placed on the stage 8 with the stage 8 moving downward. Thereafter, the stage 8 is raised and heat-treated in a state where it is fixed at a predetermined position.
After the heat treatment is completed, the stage 8 is lowered again, and the heated object to be heated is taken out and transported outside the apparatus.

In addition, in order to provide another reflector with the object to be heated 4 sandwiched so that more energy emitted from the light source can be used for heating the object to be heated 4 by effectively using infrared rays emitted from the light source. The reflecting mirror 22 can be provided around the lower part of the article 4 to be heated. The shape of the reflecting mirror 22 is arbitrary, and the infrared rays irradiated from the light source are reflected by the reflecting mirror 22, and for example, the stage 8 can be heated. When the stage 8 is heated, the object to be heated 4 is heated by irradiating the upper surface with infrared rays, and is also heated from the lower surface of the object to be heated 4 by heat conduction from the heated stage 8. it can.
As the apparatus is used, the radiant heat emitted from the heated stage 8 is also reflected by the reflecting mirror 22 and can be used as energy for heating the stage 8 again.
Further, when such a reflecting mirror 22 is adopted and the stage 8 needs to be moved up and down, as shown in the figure, another member is provided so that the reflecting mirror 22 can be separated by a separation line L. The inner reflecting mirror portion can be moved up and down while being integrated with the stage 8 by being fixed to the support 9.

Furthermore, as shown in FIG. 2C, in the present invention, the entire shape of the reflecting mirror 2 may not be a spheroid, and for example, a cylindrical reflecting mirror is connected continuously to the reflecting mirror portion of the spheroid. Can be made. When the reflecting mirror 2 having such a structure is adopted, the infrared rays generated from the light source are guided by, for example, reflecting the inner surface of the reflecting mirror more than once to a place closer to the object to be heated. And infrared rays can be prevented from leaking in the other direction from between the reflecting mirror and the object to be heated, and heating can be performed more efficiently.
Thus, it is possible to make the heating furnace of the present invention by combining the structures shown in FIGS. 1 and 2 singly or in combination.

Such a heating furnace of the present invention will be described as a specific structure.
FIG. 3 shows a heating furnace before introducing an object to be heated. In this figure, a light source 1 that generates infrared rays is provided in a reflecting mirror 2, and a hood 21 is installed above the reflecting mirror 2. Around the base of the light source, a gap through which airflow can pass is provided between the reflecting mirror 2 and the light source 1. Further, a gap is provided also in a portion surrounding the reflecting mirror 2 so that airflow can be introduced into the hood 21 through this gap. Further, at the lower part of the reflecting mirror 2, a gap is provided between the outer edge of the reflecting mirror and a member that transmits infrared rays, such as a quartz plate facing the reflecting mirror, so that airflow can pass therethrough.
In such a configuration, when the heating furnace of the present invention is operated, air currents are introduced from the gaps by generating air currents toward the arrows shown in FIG. 3 by fins provided in the hood 21. Thus, the air flow cools the inner and outer surfaces of the reflecting mirror 2 and the light source 1.

In the heating furnace shown in FIG. 3, the object to be heated has not yet been introduced into the heating furnace.
In FIG. 3, the stage provided in the upper part of the support body 9 is located at the same height as the port P for introducing an object to be heated from the outside.
In this state, although not shown, an object to be heated such as a wafer passes through the port P and is placed on the stage 8 by an external transfer means.
On the stage 8, the object to be heated is fixed so as not to move on the moving stage by means not shown.

Next, as shown in FIG. 4, the stage 8 and the object to be heated 4 thereon are moved upward together with the support 9, and are positioned at the place where the heating is to be performed. At the position shown in FIG. 4, the infrared light emitted from the light source 1 is irradiated directly or reflected by the reflecting mirror 2 or the reflecting mirror 22 and heated to a predetermined temperature. It is supplied toward the surface of the object to be heated and heated by the heat of the surface of the object to be heated, and a layer made of a reaction with the surface of the object to be heated or a reaction product is laminated on the surface of the object to be heated.
The properties of the surface of the object to be heated at this time may be measured with various thermometers installed at arbitrary locations, or the formation status of the layers may be monitored and measured through the holes provided in the reflecting mirror 2 by the camera C. .

Up to this point, an example with one light source and one reflecting mirror has been described. For example, two or more sets of light sources and reflecting mirrors are prepared and arranged so that their optical axes are parallel, or If the optical axis is tilted by, for example, about 0 to 30 ° to heat the surface of the object to be heated, unevenness in the intensity of infrared rays applied to the surface of the object to be heated can be eliminated.
The shortest linear distance between the infrared lamp 1 and the center of the object to be heated for efficient heating and downsizing of the apparatus is 70 to 200 mm, and preferably 80 to 150 mm.
When this distance increases, efficient heating and downsizing become difficult, and when the distance is small, operation of the apparatus and uniform heating may be difficult.
Furthermore, the structures shown in these drawings can be employed individually or in combination.

The condenser mirror type heating furnace shown in FIG. 5 is an application example of the condenser mirror type heating furnace shown in FIG. 4, and FIG. 6 is an enlarged view of the vicinity of the surface of the object to be heated in FIG.
This is an apparatus in which a gas g outlet 23 is provided in the window member 7 facing the object to be heated 4. At this time, the window member 7 is composed of two infrared transmissive members installed with a gap therebetween, and the gas g circulates through a distribution path provided between the two infrared transmissive members.
Since the flowing gas g is directly injected onto the surface of the object to be heated from the jet port facing the surface of the object 4 to be heated, the gas g is uniformly injected on the surface of the object to be heated, so that the atmosphere is uniform. For example, even when the gas g reacts with the surface of the article to be heated 4 under heating conditions to form a reaction film, a more uniform reaction film can be formed.
In addition, it is preferable that the nozzle 23 is provided with many fine holes from the point of performing a more uniform process.

Although not shown, the condensing mirror type heating furnace of the present invention has a structure supported by a support member in the frame cover like the known heating furnace, and houses the condensing mirror type heating furnace. Consists of a top plate, a front door, a side plate, a back plate, and a bottom plate, and an object to be heated is inserted and removed by opening and closing the front door. The top plate may be provided with an opening for inserting a long member such as a quartz tube used for producing a single crystal, and the top plate, the side plate, the back plate, and the bottom plate are provided with infrared lamps. Power supply cord, cooling water supply and discharge pipe, and an opening for passing the gas supply and discharge pipe for circulating the processing gas in the condenser mirror heating furnace, an infrared lamp, and When both the reflecting surfaces are cooled with cooling air, an opening through which a pipe for supplying and discharging the cooling air can be provided.
Furthermore, if a viewing window is provided in the frame cover, the heated object can be observed from outside the apparatus.
The frame cover containing the condenser mirror type heating furnace of the present invention can be installed on a gantry. Various devices for operating the heating furnace, such as a heating furnace power supply and controller, a radiator, a cooling water circulation device, a cooling air supply device, and a moving object moving device, may be installed on the gantry.

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Reflector 3 ... Space 4 ... Object to be heated 5 ... Space 6 ... Wall 7 ... Window member 8 ... Stage 9 ... Support 10 .. Opening 11... Hole 21... Hood 22 .. Reflector 23 .. Spout N ... Nozzle F ... Fin g ... Gas L ... Separation Line C ... Camera P ···port

Claims (14)

A condenser mirror type heating furnace for heating the object to be heated by reflecting the light emitted from the light source with a reflecting mirror and irradiating the object to be heated,
The light source, the reflector and the object to be heated are located in separate and separate chambers separated by a wall having an infrared transparent window member;
A condensing mirror type heating furnace in which light irradiated on the surface of an object to be heated is transmitted to the window member that is transparent to infrared rays and irradiated on the object to be heated.   The condensing mirror system according to claim 1, wherein the reflecting mirror is a concave mirror, and a diameter of a surface facing the reflecting mirror in a space for storing an object to be heated during heating is larger than a diameter of the opening. heating furnace.   The condensing mirror type heating furnace according to claim 1 or 2, wherein a hole is provided in the vicinity of the light source mounting portion of the reflecting mirror, and cooling air is supplied into the reflecting mirror through the hole.   A hole is provided in the bottom part of the reflecting mirror farthest from the object to be heated, a hood surrounding the reflecting mirror is provided, an exhaust device is provided in the hood, and the reflecting mirror and the light source are cooled. Condenser mirror type heating furnace.   The condensing mirror type heating furnace according to any one of claims 1 to 4, wherein the infrared transmissive window member functions as a concave lens or a convex lens.   The condensing mirror type heating furnace according to any one of claims 1 to 5, wherein an infrared focal point formed by reflection is not located on the surface of the object to be heated.   The condensing mirror type heating furnace according to claim 1, wherein another reflecting mirror is provided with an object to be heated sandwiched between the reflecting mirrors.   The condensing mirror type heating furnace according to any one of claims 1 to 7, wherein the reflecting mirror is made of a glass material as a substrate and an infrared reflecting layer is provided on an inner surface thereof.   The condensing mirror type heating furnace according to claim 1, wherein a lens made of an infrared transmitting material is provided in an opening of the reflecting mirror.   The condensing mirror system heating furnace in any one of Claims 1-9 which provided the gas jet nozzle facing this to-be-heated material surface so that the to-be-heated material surface might become a specific atmosphere.   The light source and the reflecting mirror are provided in a room where the window facing the opening of the reflecting mirror is infrared transmissive, and the object to be heated is placed in a room whose surface on the light source and reflecting mirror side is an infrared transmissive window member. The condensing mirror system heating furnace in any one of Claims 1-10 provided.   Between the window of the chamber provided with the light source and the reflector and the window of the chamber provided with the object to be heated, a gas flow path is provided between the two infrared transmissive window members. The condensing mirror type heating furnace according to claim 11, wherein a gas jet port communicating with the gas flow path is provided in an indoor window member provided with an object to be heated.   The condensing mirror type heating furnace according to any one of claims 1 to 12, wherein the chamber in which the object to be heated is provided is entirely made of quartz.   The condenser mirror heating furnace according to any one of claims 1 to 13, which is used for an object to be heated having a diameter of 50 mm or less.