JP4560660B2 - Semiconductor heat treatment apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor heat treatment apparatus and method, and more particularly, to a single wafer type semiconductor heat treatment apparatus and method for performing rapid heat treatment.
[0002]
[Prior art]
Conventionally, in a single wafer type semiconductor heat treatment apparatus, since it is necessary to rapidly heat a semiconductor wafer in a short time, a cold wall type lamp annealing apparatus with good temperature rise has been mainly used. However, the lamp annealing apparatus has poor temperature uniformity at the time of temperature rise, and with the increase in the diameter of the semiconductor wafer, the temperature distribution in the semiconductor wafer tends to be non-uniform and affected by thermal stress. There is a problem that slip occurs. The lamp annealing apparatus also has problems such as high power consumption and short lamp life.
[0003]
On the other hand, the invention listed in Patent Document 1 is of a hot wall type with good temperature uniformity. According to Patent Document 1, when heating the radiant heat source, NoboriAtsushisei is poor, using the long life, low power consumption resistance heating element. The susceptor, which is a radiant heat source, can be kept at a high temperature by always energizing the resistance heating element. Thereby, since the reaction chamber can be maintained at a high temperature, the above-described poor temperature rise property can be compensated. In addition, when a semiconductor wafer is inserted into or pulled out from a reaction chamber held at a high temperature, a temperature difference occurs between the side inserted first in the reaction chamber and the side inserted later. The temperature difference generated in this case is improved by placing the semiconductor wafer on a transfer jig so that it can be inserted into or extracted from the reaction chamber at a high speed.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-176822
[Problems to be solved by the invention]
However, in the above-described apparatus, it is necessary to take out the semiconductor wafer after heating from the reaction chamber and cool it in another apparatus. In addition, a space for installing a cooling device is required. Furthermore, since the resistance heating element always transmits power, there is a problem that wasteful power is consumed. For this reason, in the conventional apparatus, the apparatus with favorable temperature raising / lowering property, good temperature uniformity, and low power consumption was not realizable.
[0006]
In the present invention, the above problems are solved, temperature uniformity is good, high-speed temperature rise and temperature drop is possible, and the temperature distribution of the semiconductor wafer is good even at the time of temperature drop, and power consumption and cooling gas consumption are reduced. An object of the present invention is to provide an inexpensive semiconductor heat treatment apparatus and method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor heat treatment apparatus according to the present invention is a single wafer type semiconductor heat treatment apparatus, in which a process tube capable of horizontally installing a semiconductor wafer and a cross-sectional shape covering the process tube are made into an ellipse. A susceptor made of a conductor, and an induction heating coil that covers the susceptor while providing a gap so that the winding shape is similar to the susceptor and the spacing between the susceptor is constant, and upper and lower surfaces of the process tube A space partitioned by the partition is provided between the susceptor and an air supply / exhaust duct communicating with each of the partitioned spaces, and an air supply / exhaust port of the duct is provided above the process tube. It is characterized by being set point-symmetrically on the lower surface . In such a case, the wall surface of the susceptor facing the planar portion of the semiconductor wafer may be parallel to the planar portion of the semiconductor wafer.
[0008]
The semiconductor wafer may be arranged at a central position in the process tube so that the distance from the upper and lower surfaces of the semiconductor wafer to the susceptor is equal.
[0010]
Further, the semiconductor heat treatment method according to the present invention includes a process tube, a susceptor having an elliptical cross-sectional shape covering the process tube, and an induction heating having a winding shape similar to the susceptor arranged to cover the susceptor. A heat treatment method using a single-wafer type semiconductor heat treatment apparatus having a coil, wherein the semiconductor wafer is horizontally disposed in the process tube, and the gap between the susceptor and the gap is constant. A step of heating the semiconductor wafer by transmitting power to the induction heating coil and heating the susceptor, and a supply / exhaust duct provided on the upper and lower surfaces of the process tube and communicating with each of the spaces partitioned by the partition to face the two flat portions of the wall and is the semiconductor wafer process tube interior of the semiconductor wafer via The wall surface, the cooling gas is blown to the opposite direction of flow in both wall surfaces, and having a step of performing cooling of the semiconductor wafer. In this case, it is preferable to adjust the supply amount of the cooling gas so as to equalize the heat dissipation amount of the semiconductor wafer.
[0011]
[Action]
As described above, a process tube in which a semiconductor wafer can be installed horizontally, a susceptor having an elliptical cross-sectional shape covering the process tube, and an induction heating coil having a similar shape covering the susceptor, As a result, since the induction heating coils are arranged in the same shape along the susceptor, the uniformity of the temperature distribution on the inner surface of the wafer is improved, and the input power for heating the susceptor can be reduced.
Further, by making the wall surface of the susceptor and the planar portion of the semiconductor wafer parallel, the distance between the surface of the semiconductor wafer and the wall surface of the susceptor of the radiant heat source becomes equal.
[0012]
Further, the semiconductor wafer is arranged at a central position in the process tube, and the distance from the upper and lower surfaces of the semiconductor wafer to the susceptor is equal to each other, so that the upper and lower plane portions and the susceptor of the semiconductor wafer are equal. And the radiant heat is uniformly transmitted to the upper and lower surfaces of the semiconductor wafer.
[0013]
In addition, a space is provided between the upper and lower surfaces of the process tube and the susceptor, and air supply / exhaust ducts communicating with the space are respectively provided. By setting the point symmetry at, the cooling gas can flow in the opposite direction above and below the semiconductor wafer.
[0014]
That is, the cooling gas is flown in the opposite direction on one side and the other side of the heated semiconductor wafer on the wall of the process tube that houses the semiconductor wafer, with the process tube as a boundary. Since the heat absorption is performed from the supply side to the exhaust side, the temperature gradient increases as it goes to the exhaust side, but the temperature gradient is made constant by supplying the cooling gas in the reverse flow on the opposite surface of the semiconductor wafer. be able to.
The cooling gas supplied to the upper and lower spaces of the process tube can be adjusted according to the balance of the heat radiation amount of the wafer.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments according to the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of an embodiment according to the present invention, FIG. 2 is a transverse sectional view, and FIG. 3 is a partial sectional perspective view.
[0016]
The basic configuration of this embodiment includes a process tube 12 in which the wafer 10 can be housed, a susceptor 14 that covers the process tube 12, and an induction heating coil 16 that surrounds the susceptor 14.
[0017]
The semiconductor heat treatment apparatus of this example is a single wafer type. The process tube 12 in which the wafer 10 is housed is preferably made of quartz, and is a box having a rectangular shape in both front and plane, in which a semiconductor wafer having a circular or rectangular shape is housed, and carries the wafer 10. The side is open. The opening is covered after the wafer 10 is transferred. In addition, an inlet 11 for injecting an inert gas or a reactive gas is provided on the opposite surface of the opening to prevent the wafer 10 from reacting with impurities during heat treatment. Further, inside the process tube 12, there is provided a support portion 20 for holding the wafer 10 horizontally in the center position inside the process tube 12.
[0018]
The process tube 12 is a radiant heat source while providing a cooling gas passing space for passing a cooling gas when the wafer 10 is cooled outside the wall surface facing the flat portion of the wafer 10. Decorated in susceptor 14. As shown in FIG. 2, the susceptor 14 has an oval (track type) cross-sectional shape, and the sides facing the plane portion of the wafer 10 are parallel to each other. In addition, the parallel plane and the plane of the wafer 10 are equidistant from each of the upper and lower planes of the wafer 10. Thereby, since the distance between the wafer 10 and the radiant heat source becomes equal throughout, the radiant heat is evenly transmitted to the wafer 10 and the wafer 10 can be uniformly heated from both sides.
[0019]
The outer periphery of the susceptor 14 has a similar shape and is provided with an induction heating coil 16 surrounding the susceptor 14. In addition, the induction heating coil 16 is preferably arranged so as to have an equal interval from any point of the susceptor 14. Thereby, the magnetic flux density affecting the susceptor can be equalized.
By making the induction heating coil 16 similar to the susceptor 14, the distance between the susceptor 14 and the induction heating coil 16 is constant, and the magnetic flux during power transmission uniformly affects the susceptor 14. The susceptor 14 can be heated uniformly. Further, by adopting an induction heating method for heating the susceptor 14, the temperature of the wafer 10 can be raised at a rate of temperature increase of about 10 times (about 1000 ° C./min) compared to the conventional resistance heating method. Therefore, it is not necessary to always transmit power to the induction heating coil 16. Further, since the induction heating coil itself does not generate heat when the temperature is lowered, the susceptor 14 is not further heated by radiant heat of the heating body after power transmission is cut off, and is about 10 times (about 500 ° C.) as compared with the resistor heating system. / Min).
[0020]
In the cooling gas passage space provided between the susceptor 14 and the two wall surfaces which are the wall surfaces of the process tube 12 described above and which are the upper and lower surfaces of the process tube 12 facing the planar portion of the wafer 10, A pair of ducts 18 are provided for supplying or exhausting cooling gas. In addition, the cooling gas delivery space provided above and below the process tube 12 is partitioned up and down by a partition 13 made of a heat insulating material or the like. For this reason, it becomes possible to send the cooling gas having a different flow direction and the cooling gas having different properties at the top and bottom of the process tube 12.
[0021]
In the embodiment having the above-described configuration, the wafer 10 is transferred from the opening of the process tube 12, installed on the support unit 20, and then the opening is covered. After sealing the process tube 12, the inside of the process tube 12 is evacuated. Thereafter, an inert gas or a reactive gas such as H 2 O gas or Ar is fed from an inlet 11 for injecting an inert gas or a reactive gas, whereby the air existing in the process tube 12 and the inert gas or reactive gas are contained. Replace with. Thereby, the wafer 10 can be prevented from combining with impurities during the heat treatment.
[0022]
After the above operation is completed, arbitrary power is supplied to the induction heating coil 16. The induction heating coil 16 to which power is applied generates magnetic flux. The generated magnetic flux generates an eddy current inside the susceptor 14 which is a conductor. Thereby, the susceptor 14 is heated. The heated susceptor 14 generates radiant heat and heats the wafer 10.
[0023]
After the wafer 10 is heat-treated, the power supply to the induction heating coil 16 is stopped.
Cooling gas is supplied from the duct 18a and the duct 18c to the cooling gas passage space. The cooling gas supplied from the duct 18a is exhausted from the duct 18b, and the cooling gas supplied from the duct 18c is exhausted from the duct 18d. At this time, the supplied cooling gas rises in temperature by absorbing radiant heat from the susceptor 14 and the wafer 10 as it proceeds to the exhaust side. For this reason, the temperature gradient of the cooling gas rises from the supply side to the exhaust side. However, since the cooling gas is sent in the opposite direction in the upper and lower spaces with the process tube 12 as a boundary, the temperature gradient of the cooling gas in each cooling gas delivery space is as shown in FIG. For this reason, on average, the temperature gradient of the cooling gas passing through the upper and lower sides uniformly cools the wafer 10 that is the object to be cooled. At this time, the amount of cooling gas supplied is preferably about 500 l / min.
[0024]
As described above, the susceptor 14 that covers the process tube 12 is of a track type, and the wall surface of the susceptor 14 that faces the planar portion of the wafer 10 is parallel to the planar portion of the wafer 10. Since the plane portions of the susceptor 14 are substantially equidistant, the wafer 10 can be heated uniformly. Further, by making the induction heating coil 16 similar to the susceptor 14, the distance between the susceptor 14 and the induction heating coil 16 is constant, and the susceptor 14 can be heated uniformly. Further, the induction heating has high thermal efficiency because the object to be heated itself generates heat, and heat loss is small because no heat is generated except for the object to be heated. The wafer 10 is arranged at a central position inside the process tube 12 so that the distances from the upper and lower surfaces of the wafer 10 to the susceptor 14 are equal to each other. Since the distance to the susceptor 14 is equal on the surface, the radiant heat is evenly transmitted to the upper and lower surfaces of the wafer 10 and the wafer 10 can be heated uniformly.
[0025]
Furthermore, by providing a cooling gas passing space between the upper and lower portions of the process tube 12 and the susceptor 14, it is possible to send the cooling gas in the opposite direction to the upper and lower portions of the process tube 12.
[0026]
With respect to the heated wafer 10, a cooling gas is allowed to flow in the opposite direction to the wall surface of the process tube 12 that houses the wafer 10, with the wafer 10 as a boundary, on one side surface and the other side surface. As a result, the temperature gradient accompanying the endothermic action of the cooling gas is reversed up and down the process tube 12. For this reason, when both are averaged, the wafer 10 can be cooled uniformly. Further, the wafer 10 can be uniformly cooled by adjusting the supply amount of the cooling gas in accordance with the heat radiation amount of the wafer 10.
Further, by using the induction heating coil 16 as the heating device, the wafer 10 can be rapidly heated and cooled quickly.
[0027]
In the above embodiment, the process tube 12 has a rectangular shape, both front and plane, but may be a track type having the same shape as the susceptor 14. In the embodiment, the duct 18a and the duct 18c are on the cooling gas supply side, but the duct 18b and the duct 18d may be on the supply side.
In addition, although the supply amount of the cooling gas is set to about 500 l / min, the present invention is not limited to this and may be adjusted so that the temperature distribution of the wafer 10 is good.
[0028]
【The invention's effect】
By providing a process tube having a rectangular cross-section that can horizontally embed a semiconductor wafer, a susceptor having an oval side cross-sectional shape covering the process tube, and an induction heating coil having a similar shape covering the susceptor The uniformity of the temperature distribution inside the wafer is improved, and the input power when heating the susceptor can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a semiconductor heat treatment apparatus according to the present invention.
FIG. 2 is a cross-sectional view of a semiconductor heat treatment apparatus according to the present invention.
FIG. 3 is a partial cross-sectional perspective view of a semiconductor heat treatment apparatus according to the present invention.
FIG. 4 is a diagram showing a temperature gradient of a cooling gas in the semiconductor heat treatment method according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ......... Wafer, 11 ......... Inlet, 12 ......... Process tube, 13 ......... Partition, 14 ......... Susceptor, 16 ...... Induction heating coil, 18 (18a, 18b, 18c, 18d) ……… duct, 20 ……… supporting part.

Claims (5)

A single-wafer semiconductor heat treatment apparatus, a process tube capable of horizontally mounting a semiconductor wafer, a susceptor made of a conductor having an elliptical cross-sectional shape covering the process tube, and a winding shape similar to the susceptor And an induction heating coil that covers the susceptor while providing a gap so that the distance from the susceptor is constant ,
Between the upper and lower surfaces of the process tube and the susceptor, a space that is partitioned vertically by a partition and a supply / exhaust duct that communicates with each of the partitioned spaces are provided, and a supply / exhaust port of the duct Is set to be point-symmetric on the upper and lower surfaces of the process tube.   The semiconductor heat treatment apparatus according to claim 1, wherein a wall surface of the susceptor facing the planar portion of the semiconductor wafer is parallel to the planar portion of the semiconductor wafer.   The semiconductor heat treatment apparatus according to claim 2, wherein the semiconductor wafer is disposed at a central position in the process tube, and the distance from the upper and lower surfaces of the semiconductor wafer to the susceptor is equal. By a single-wafer semiconductor heat treatment apparatus having a process tube, a susceptor having an elliptical cross-sectional shape covering the process tube, and an induction heating coil having a winding shape similar to the susceptor arranged to cover the susceptor A heat treatment method comprising:
Horizontally installing the semiconductor wafer in the process tube;
Heating the semiconductor wafer by transmitting power to the induction heating coil disposed with a gap that is constant with the susceptor to heat the susceptor;
It is a wall surface of the process tube, which is provided on the upper and lower surfaces of the process tube, and communicates with each of the spaces partitioned by the partition and communicates with each of the spaces, and is provided on two planar portions of the semiconductor wafer. And a step of cooling the semiconductor wafer by blowing a cooling gas to opposite walls so as to flow in opposite directions on both wall surfaces. 5. The semiconductor heat treatment method according to claim 4 , wherein a supply amount of the cooling gas is adjusted so as to equalize a heat dissipation amount of the semiconductor wafer.

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