JP4288090B2 - Induction heating coil unit, semiconductor heat treatment apparatus and heat treatment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating coil unit, a semiconductor heat treatment apparatus, and a heat treatment method, and more particularly to an induction heating coil unit, a semiconductor heat treatment apparatus, and a heat treatment method that are suitable when a vacuum chamber is used in a heat treatment tank.
[0002]
[Prior art]
In general, in a semiconductor manufacturing process, a substrate such as a semiconductor wafer is subjected to a heat treatment such as oxidation, diffusion, or annealing. Usually, for heat treatment, the substrate is placed in a process tube and heated in a chamber. At that time, the inside of the chamber is in a vacuum state. The reason why the substrate is heat-treated in vacuum is that the adhesion of the film formed on the surface of the substrate is increased, the quality of the crystal is improved, and the like.
[0003]
As such an apparatus and method, a resistance heating type and a lamp heating type are widely used. However, the two types of heating methods have advantages and disadvantages in terms of uniform heating and rapid temperature increase, respectively. In recent years, in particular, with the increase in the diameter of semiconductor wafers, a technology capable of both uniform heating and high-speed temperature rise has been devised from the viewpoint of throughput in a single wafer type apparatus and quality maintenance in a batch type apparatus.
As such a device, there is a device described in Patent Document 1. The vacuum heat treatment apparatus of Patent Document 1 uses an induction heating coil as a heating source, and uses an induction heating body and a conductive heating body as heat generation sources.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-290864
[Problems to be solved by the invention]
However, the vacuum heat treatment apparatus described in Patent Document 1 mainly causes an induction heating coil as a heating source to be disposed in the vacuum chamber, which may cause contamination. In addition, as an example, an induction heating coil is provided outside the vacuum chamber, but in this case, the induction heating body and the conductive heating body, which are heat sources, also face the outside of the vacuum chamber. Therefore, heating may become unstable. Further, when a heating source is disposed outside the vacuum chamber and an induction heating body or a conduction heating body is to be disposed within the vacuum chamber, each of the divided surfaces is thin and light-transmitting as a shielding plate. Things are needed. In this case, for example, if the shielding plate is a quartz plate, it may break when the vacuum chamber is evacuated. Further, when the shielding plate is of a vacuum withstand voltage, for example, thick, there is a problem that the induction heating body cannot be heated sufficiently.
[0006]
In the present invention, even if the induction heating coil that can solve the above problems and cause contamination is arranged outside the vacuum chamber and the heat source is arranged inside the vacuum chamber, a sufficient heating temperature and temperature rise can be achieved. It is an object of the present invention to provide an induction heating coil unit, a semiconductor heat treatment apparatus, and a heat treatment method capable of obtaining speed.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an induction heating coil unit according to the present invention is an induction heating coil unit serving as a lid of a vacuum chamber, and includes a case in which a boundary surface with the vacuum chamber is shielded by a shielding plate. In the case, an induction heating coil disposed in the vicinity of the shielding plate, an air vent duct , a resin for covering the excess space in the case, and the shielding plate and the induction heating coil are disposed. When the inside of the case is set to a negative pressure via the air vent duct, the shielding plate is in close contact with the heat insulating material .
[0008]
In the induction heating coil unit configured as described above, the shielding plate may be a quartz plate .
[0009]
Further, the semiconductor heat treatment apparatus according to the present invention includes a case in which a boundary surface with a vacuum chamber is shielded by a shielding plate, and an induction heating coil disposed in the vicinity of the shielding plate inside the case, an air A vent duct , a resin covering the excess space in the case, and a heat insulating material disposed between the shielding plate and the induction heating coil are provided, and the inside of the case is set to a negative pressure via the air vent duct. In this case, the shield plate includes an induction heating coil unit configured to be in close contact with the heat insulating material, the susceptor is provided in the vacuum chamber close to the shield plate, and a semiconductor wafer is provided below the susceptor. It is characterized by.
[0010]
In the semiconductor heat treatment apparatus configured as described above, the shielding plate is preferably a quartz plate .
[0011]
In order to achieve the above object, a semiconductor heat treatment method according to the present invention is a heat treatment method in a semiconductor heat treatment apparatus having a structure in which a lid provided with an induction heating coil unit and a vacuum chamber are each shielded by a shielding plate, The induction heating coil that evacuates the internal space of the lid and the vacuum chamber, and has an internal space of the lid that is more negative than the internal space of the vacuum chamber, and includes an induction heating coil, a resin, and a heat insulating material. The semiconductor wafer is heat-treated after the shielding plate is brought into close contact with the heat insulating material in the unit .
[0012]
[Action]
Since the induction heating coil unit is used as a lid and the boundary surface with the vacuum chamber is shielded by the shielding plate, the induction heating coil is disposed outside the vacuum chamber. Therefore, the cause of contamination in the vacuum chamber can be suppressed. In addition, by using a quartz plate as the shielding plate, the light transmittance is good. Further, by providing a heat insulating material between the shielding plate and the induction heating coil, it is possible to prevent the insulation coating of the induction heating coil from being spilled by radiant heat from the induction heating body provided in the vacuum chamber. can do. By providing an air vent duct in the case of the shielded lid, the lid side can be evacuated according to the degree of vacuum on the vacuum chamber side. Therefore, an excessive burden is not imposed on quartz as a shielding plate. For this reason, even if quartz is a thin plate, there is no possibility of cracking.
[0013]
By providing the lid that performs the above operation in the vacuum chamber and using the semiconductor heat treatment apparatus, the induction heating coil is not disposed in the vacuum chamber, and contamination can be suppressed. In addition, since both the lid and the vacuum chamber can be evacuated, there is no risk that the quartz will be broken under the influence of atmospheric pressure even if the shielding quartz is a thin plate. . Furthermore, by using quartz as a thin plate, the induction heating body can be sufficiently induction heated even if the induction heating coil is provided on the lid body side and the induction heating body is provided on the vacuum chamber side. Furthermore, since the induction heating body is provided in the vacuum chamber, when the semiconductor wafer is heated, the space interposed between the semiconductor wafer and the induction heating body can be reduced. Uniform radiation heating can be performed.
[0014]
In the case of vacuuming as described above, the quartz is bent by its own weight when the apparatus is enlarged by making the internal space on the lid side have a negative pressure than the internal space on the vacuum chamber side. Can be prevented.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of an induction heating coil unit, a semiconductor heat treatment apparatus, and a heat treatment method according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of the induction heating coil unit according to the first embodiment. The basic configuration of the induction heating coil unit 10 of the present embodiment includes a casing 12 serving as an exterior, an induction heating coil 14 disposed inside the casing 12 as a heating source, and a resin 18 filled in the casing 12. Consists of.
[0016]
The casing 12 is a cylindrical container made of a material such as stainless steel, which is relatively excellent in corrosion resistance and heat resistance, and is inexpensive to manufacture, and has a flange at the opening. Further, a groove 19 is formed over the entire circumference of the flange.
[0017]
The induction heating coil 14 is formed of a material having excellent electrical conductivity such as copper and having a low manufacturing cost. The induction heating coil 14 is formed in a tubular shape in order to prevent the coil itself from overheating, and allows cooling water, a coolant, or a cooling gas to pass through (for example, a water-cooled copper pipe). . Since the induction heating coil 14 is a heating source, it is desirable that the induction heating coil 14 be disposed in the vicinity of the opening of the casing 12, and the arrangement shape should be a so-called Baumkuchen type so as to be concentric with the casing 12. The material of the casing 12 is not limited to stainless steel as long as the inside can be evacuated.
[0018]
Positioning of the induction heating coil is facilitated if the induction heating coil is placed after filling an epoxy resin 18 such as a thermosetting resin in a portion of the casing 12 which becomes an extra space. The epoxy resin 18 serves to insulate the surface of the induction heating coil 14, and fills the surplus space to prevent air from entering the induction heating coil unit 10.
[0019]
The opening of the casing 12 is shielded by a quartz plate 22 which is a light transmission type shielding plate and has excellent heat resistance. At this time, the groove portion 19 is provided with an O-ring 20 that performs a sealing effect.
[0020]
In the above configuration, a slight gap is provided between the quartz plate 22 and the induction heating coil 14. The gap is provided with a heat insulating material 21 made of powder such as alumina, a paste containing powder, or a plate material formed of alumina or the like. The heat insulating material 21 prevents dripping of the resin 18 covering the surface of the induction heating coil 14 due to the radiant heat when the induction heating body 26 described later is heated by the induction heating coil 14. Further, the heat insulating member 21 also serves to prevent the heat-induced heating member 26 emits an induction heating coil 14 is water-cooled copper tube ends up absorbed, thereby lowering the temperature of the induction heating body 26.
[0021]
Further, an air vent duct 16 for evacuating the internal space of the induction heating coil unit 10 to an extent equal to or higher than the internal vacuum degree of the vacuum chamber 24 described later faces the gap provided with the heat insulating material 21.
The semiconductor heat treatment apparatus according to the present embodiment may be configured as shown in FIGS. In other words, the induction heating coil unit 10 and the vacuum chamber 24 provided with the induction heating coil unit 10 as a lid are configured with the quartz plates 22 as respective boundary surfaces.
[0022]
The vacuum chamber 24 is not particularly limited in shape and material, but may be configured as follows, for example.
The vacuum chamber 24 is a cylindrical container formed of stainless steel or the like, which is the same material as the casing 12, and has an opening with a flange similar to the casing 12. The cylindrical portion is provided with a transfer gate 38 for loading or unloading the semiconductor wafer 28 and the like, and an air vent duct 40 for evacuating the inside of the vacuum chamber 24.
[0023]
Inside the vacuum chamber 24 is a support portion for supporting an induction heating body 26 formed by coating silicon carbide on graphite or carbon (carbon), which is one of carbon allotropes, in the vicinity of the quartz plate 22. 32 is provided to support the induction heating body 26 horizontally at at least three points.
[0024]
Further, a wafer support 30 that horizontally supports the semiconductor wafer 28 at at least three points is connected to a cylinder rotation shaft 42 that is provided at the bottom of the vacuum chamber 24 and that can be freely extended and retracted.
A flange surface along the opening surface of the vacuum chamber 24 and in close contact with the quartz plate 22 is provided with a groove portion 19 similar to the flange of the casing 12 and an O-ring 20 that provides a sealing effect.
[0025]
A vacuum pump 44 or the like may be used as the evacuation means of the semiconductor heat treatment apparatus 1 having the above configuration. Specifically, one port of the pressure hose 36 or the like may be connected to the suction side of the vacuum pump 44 and the other port may be connected to the air vent ducts 16 and 40. The vacuum pump 44 does not need to be vacuumed from one place for one pump, but vacuums many places simultaneously by means such as branching the pressure hose 36 in the middle. You can also.
[0026]
In the semiconductor heat treatment apparatus 1 configured as described above, as preparation for heat treatment, first, the semiconductor wafer 28 is carried from the transfer gate 38 to the wafer support portion 30 inside the vacuum chamber 24 and arranged. At this time, the wafer support 30 is lowered to the position indicated by the two-dot chain line in FIG. After carrying in the semiconductor wafer 28, the transfer gate 38 is closed, the cylinder rotating shaft 42 is extended, and the wafer support 30 is moved to the heating position.
[0027]
Thereafter, the vacuum pump 44 is turned on, and the induction heating coil unit 10 and the vacuum chamber 24 are evacuated through the air vent ducts 16 and 40 and the pressure hose 36. The evacuation is preferably performed such that the induction heating coil unit 10 has a negative pressure (high vacuum) as compared with the vacuum chamber 24. As a result, even if the quartz plate 22 is a thin plate, there is no possibility that the quartz plate 22 is bent due to its own weight when the quartz plate 22 is enlarged with an increase in the diameter of the semiconductor wafer 28. In addition, after evacuation, a vacuum state may be maintained by a check valve (not shown) or the like.
[0028]
In the above state, the O-ring 20 is sandwiched between the quartz plate 22, the induction heating coil unit 10, and the vacuum chamber 24, and is brought into close contact while being crushed, thereby sealing the joint surface.
[0029]
When preparation for heat treatment is completed as described above, necessary power is supplied to the induction heating coil 14 to heat the induction heating body 26. At the same time, cooling water or the like is flowed into the induction heating coil 14 to prevent self heating. The heated induction heating body 26 generates heat by the action of eddy current, heats the semiconductor wafer 28 by the radiant heat, and performs processing such as film formation. At this time, by providing the heat insulating material 21 between the induction heating coil 14 and the quartz plate 22, it is possible to prevent the resin 18 that insulates the induction heating coil 14 from being overheated and dripping. .
[0030]
Moreover, there exists a thing as shown in FIG. 3 as 2nd Embodiment of the semiconductor heat processing apparatus 1. FIG. Since the basic configuration of the semiconductor heat treatment apparatus 1 shown in FIG. 3 is the same as that of the first embodiment, a description thereof will be omitted. As a difference, in this embodiment, the casing 12 of the induction heating coil unit 10 has a shape in which a bottom plate is attached to a cylinder having an outer shape that fits the inner diameter of the vacuum chamber 24 and can be fitted into the vacuum chamber 24. The vacuum chamber 24 is configured such that a quartz plate 22 as a shielding plate is disposed at a position where the opening of the casing 12 is located. As a result, the inside of the vacuum chamber 24 is divided into two layers by the quartz plate 22. In this case, in order to fit the induction heating coil unit 10 to the vacuum chamber 24, the induction heating coil unit 10 is arranged inside the vacuum chamber 24, but each internal space is shielded by the quartz plate 22. Therefore, evacuation can be performed as a separate space.
Sealing among the induction heating coil unit 10, the quartz plate 22, and the vacuum chamber 24 is not shown, but can be performed by an O-ring as in the first embodiment.
[0031]
In the induction heating coil unit 10 and the semiconductor heat treatment apparatus 1 as described above, the induction heating coil unit 10 is used as a lid, and the boundary surface with the vacuum chamber is shielded by the quartz plate 22. It will be arranged outside the vacuum chamber 24, and the cause of contamination in the vacuum chamber 24 can be suppressed. Further, by providing a heat insulating material 21 between the quartz plate 22 and the induction heating coil 14, the induction heating coil 14 is fixed by radiant heat from the induction heating body 26 provided inside the vacuum chamber 24. It is possible to prevent the resin 18 having an insulating coating from dripping. In addition, the induction heating coil 14 is a water-cooled copper pipe or the like so as to prevent self overheating, so the temperature is relatively low. Therefore, it is possible to prevent the induction heating coil 14 from absorbing the heat of the induction heating body . By allowing the air vent duct 16 to face the space having the heat insulating material 21 to enable vacuuming, the induction heating coil unit 10 side can also be evacuated according to the degree of vacuum on the vacuum chamber 24 side. Therefore, an excessive burden is not imposed on the quartz plate 22. For this reason, there is no possibility of cracking even if the quartz plate 22 is a thin plate.
[0032]
Furthermore, by making the quartz plate 22 thin, the induction heating coil 14 that is a heating source and the induction heating body 26 that is a heat generation source are disposed in the induction heating coil unit 10 and the vacuum chamber 24, respectively. However, since each distance is comparatively close, sufficient induction heating can be performed.
[0033]
Further, by providing the induction heating coil unit 10 having the above-described function in the vacuum chamber 24 and using the semiconductor heat treatment apparatus 1, the induction heating coil 14 is not disposed in the vacuum chamber 24, and contamination is suppressed. be able to. In addition, since both the induction heating coil unit 10 and the vacuum chamber 24 can be evacuated, even if the quartz plate 22 that shields each is a thin plate, the quartz plate 22 has an atmospheric pressure or the like. There is no risk of cracking under the influence. Further, by making the quartz plate 22 a thin plate, the induction heating coil 26 is sufficiently induction heated even if the induction heating coil 14 is provided on the induction heating coil unit 10 side and the induction heating body 26 is provided on the vacuum chamber 24 side. can do. Furthermore, since the induction heating body 26 is provided inside the vacuum chamber 24, when the semiconductor wafer 28 is heated, the gap interposed between the semiconductor wafer 28 and the induction heating body 26 is reduced. Therefore, stable and uniform radiation heating can be performed.
[0034]
In the above-described evacuation, the quartz plate 22 becomes larger when the apparatus is enlarged by making the internal space on the induction heating coil unit 10 side have a negative pressure than the internal space on the vacuum chamber 24 side. It is possible to prevent bending due to its own weight.
[0035]
In the above embodiment, the spaces of the induction heating coil unit 10, the quartz plate 22, and the vacuum chamber 24 are sealed by O-rings, but other sealing means such as sheet packing may be used. good.
[0036]
In the embodiment, two vacuum pumps 44 are used as shown in FIG. 2 for evacuation, and the induction heating coil unit 10 and the vacuum chamber 24 are evacuated separately, as shown in FIG. Thus, vacuuming may be performed by a single vacuum pump. In this case, in order to give a difference in the degree of vacuum in each space, a valve (not shown) may be closed when the set pressure with the lower degree of vacuum is reached, and the other vacuuming is continued. Thereby, the installation cost and installation space of the vacuum pump 44 can be reduced.
[0037]
Furthermore, in the embodiment, the induction heating coil 14 is arranged in a balm Kuchen type, but may be in a distorted shape as long as the induction heating body 26 can be heated uniformly. Moreover, although the shape of the induction heating coil unit 10 and the vacuum chamber 24 is a cylindrical shape, it may be a rectangular shape or a polygonal shape as long as it is a preferable requirement and has the same effect. In the embodiment, the structure of the vacuum chamber 24 is specifically described. However, the structure is not limited to two examples in the embodiment, and the boundary with the induction heating coil unit 10 is not limited thereto. Any material can be used as long as the surface can be shielded by the quartz plate 22 and the inside can be evacuated.
[0038]
In the embodiment, the resin 18 is filled in the surplus space of the casing 12. However, the induction heating coil 14 may be merely covered with an insulating film.
The induction heating coil 14 may be divided into a plurality of zones. In that case, it is only necessary to be able to avoid the influence of mutual induction that occurs during the control of each coil. Thereby, the temperature of the induction heating body 26 can be controlled for each zone, and the temperature control of the semiconductor wafer 28 can be performed more precisely.
[0039]
【The invention's effect】
As described above, the induction heating coil unit of the present invention is an induction heating coil unit that serves as a lid of a vacuum chamber, and includes a case in which a boundary surface with the vacuum chamber is shielded by a shielding plate. Is an induction heating coil disposed in the vicinity of the shielding plate, an air vent duct , a resin covering the excess space in the case, and a heat insulating material disposed between the shielding plate and the induction heating coil. When the inside of the case is set to a negative pressure through the air vent duct, the shield plate is configured to be in close contact with the heat insulating material. Contamination can be suppressed without being disposed. In addition, since both the lid and the vacuum chamber can be evacuated, there is no risk that the quartz will be broken under the influence of atmospheric pressure even if the shielding quartz is a thin plate. . Furthermore, since the induction heating body is provided in the vacuum chamber, when the semiconductor wafer is heated, the space between the semiconductor wafer and the induction heating body can be narrowed, so that stable and uniform radiation heating is possible. Can do.
[Brief description of the drawings]
FIG. 1 shows a cross-sectional view of a first embodiment of an induction heating coil unit according to the present invention.
FIG. 2 is a diagram showing a configuration of a first embodiment of a semiconductor heat treatment apparatus according to the present invention.
FIG. 3 is a diagram showing a configuration of a second embodiment of a semiconductor heat treatment apparatus according to the present invention.
FIG. 4 is a diagram showing a configuration for performing evacuation in an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ......... Semiconductor heat processing apparatus, 10 ......... Induction heating coil unit, 12 ......... Casing, 14 ......... Induction heating coil, 16 ...... Air venting duct, 18 ......... Resin, 20 ......... O Ring, 22... Quartz plate, 24... Vacuum chamber, 26... Induction heater , 28.

Claims (5)

An induction heating coil unit serving as a lid of a vacuum chamber, comprising a case in which a boundary surface with the vacuum chamber is shielded by a shielding plate, and an induction disposed in the case in the vicinity of the shielding plate A heating coil, an air vent duct , a resin that covers excess space in the case, and a heat insulating material disposed between the shielding plate and the induction heating coil are provided, and the interior of the case is provided via the air vent duct. An induction heating coil unit , wherein the shielding plate is in close contact with the heat insulating material when a negative pressure is applied.   The induction heating coil unit according to claim 1, wherein the shielding plate is a quartz plate. A case in which a boundary surface with the vacuum chamber is shielded by a shielding plate is provided, and an induction heating coil disposed in the vicinity of the shielding plate, an air vent duct , and excess space in the case are covered inside the case. A resin and a heat insulating material disposed between the shielding plate and the induction heating coil are provided, and when the inside of the case is set to a negative pressure through the air vent duct, the shielding plate becomes the heat insulating material. A semiconductor heat treatment apparatus comprising: an induction heating coil unit configured to be in close contact; a susceptor provided in the vacuum chamber adjacent to the shielding plate; and a semiconductor wafer provided below the susceptor.   The semiconductor heat treatment apparatus according to claim 3, wherein the shielding plate is a quartz plate. A lid and a vacuum chamber comprising an induction heating coil unit, a heat treatment method in a semiconductor heat treatment apparatus having the structure are each shielded by the shielding plate, the evacuated interior space of the cover and the vacuum chamber, respectively, wherein The internal space of the lid is set to a negative pressure than the internal space of the vacuum chamber, and after the shielding plate is brought into close contact with the heat insulating material in the induction heating coil unit having the induction heating coil, resin, and heat insulating material , the semiconductor wafer The semiconductor heat processing method characterized by performing heat processing of this.

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