KR20040075561A - System Of Heating Wafer And Method Of Operating The Same - Google Patents

Abstract

PURPOSE: A wafer heating system and an operating method thereof are provided to heat uniformly a wafer and enhance the efficiency in a thermal process by performing an inductive heating method using eddy current. CONSTITUTION: A wafer is arranged on a reactor(110). A plurality of coils(120) are wound around an outer wall of the reactor. A generator(130) is connected to the coils. The reactor is formed with one of a furnace type reactor and a batch type reactor. The coils wound around the outer wall of the reactor are formed with two or more coils. A conducting plate is installed in the inside of the reactor. A control unit controls operations of the generator.

Description

Wafer heating system and operating method thereof {System Of Heating Wafer And Method Of Operating The Same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus and a method of operating the same, and more particularly, to an apparatus for controlling a temperature of a wafer and a method of operating the same.

The manufacturing process of the semiconductor device is largely divided into a photo process, an etching process, a deposition process and a thin film process according to the type. In this case, the deposition process and / or the thin film process generally consists of a chemical reaction involving a thermal process. The thermal process increases the reaction rate of the chemical reaction, or serves to supply the minimum energy, that is, the activation energy that can occur.

This increase in reaction rate increases the manufacturing productivity of the semiconductor device in terms of cost, but can cause thermal damage to the product if excessively long lasting. In particular, the thermal process performed at high temperature causes problems such as poor wiring caused by melting aluminum or the like, structural collapse due to melting of the interlayer insulating film, diffusion of impurity regions and thus short channel effect.

In order to minimize the problem of the thermal process, it is required to heat the inside of the reactor in which the substrate is placed to the required process temperature, but to minimize the total amount of thermal energy applied to the substrate. In order to minimize the total amount of thermal energy, a method of reducing the time for heating the substrate, that is, a method of heating the substrate quickly is required.

Rapid heating of the substrate is a particularly important problem in molecular layer epitaxy (MLE) technology. Rapidly changing the temperature of the substrate in the MLE is an important technical task required to form a high quality epitaxial layer, together with the problem of reducing the total amount of thermal energy as described above.

Typically, MLE systems employ a method of heating a single wafer with a ramp. In this way, multiple wafers cannot be processed at the same time, resulting in poor productivity. MLE systems, on the other hand, can also use quartz furnaces or batch type reactors that can handle multiple wafers. However, since the quartz furnace or batch reactor has a large heat capacity of its own, the heating method using the lamp cannot change the temperature of the substrate rapidly. Accordingly, when using the MLE system according to the prior art, it is difficult to form a good epitaxial layer.

The technical problem to be achieved by the present invention is to provide a wafer heating system that can quickly heat the temperature of the wafer.

Another object of the present invention is to provide a method of operating a wafer heating system for rapidly heating a temperature of a wafer.

1 is a view for explaining a eddy current caused by a change in the magnetic flux flux.

2 is a schematic view illustrating a wafer heating system and a method of operating the wafer heating system according to an exemplary embodiment of the present invention.

3 and 4 are cross-sectional views illustrating a wafer heating system according to embodiments of the present invention.

In order to achieve the above technical problem, the present invention provides a system for heating a wafer using eddy currents. The system includes a reactor in which a wafer is placed, a coil wound on an outer wall of the reactor, and a generator connected to the coil.

According to one embodiment of the present invention, the reactor is either a furnace type or a batch type capable of loading multiple wafers.

Preferably at least two coils are wound around the outer wall of the reactor. In addition, a conductor plate in contact with the wafer may be further disposed in the reactor.

According to a preferred embodiment of the present invention, the generator may be further attached to a controller for controlling the operation. In addition, the generator is preferably a radio wave alternator.

In order to achieve the above another technical problem, the present invention provides a method for operating a wafer heating system having a reactor in which a wafer is disposed and a coil wound around an outer wall of the reactor in an induction heating method. That is, the method includes heating the wafer by varying the density of the magnetic flux of flux generated by the current flowing through the coil.

As a method of changing the density of the magnetic flux flux, a method of changing the strength and direction of the current flowing through the coil may be used. That is, the heating of the wafer uses an eddy current induced by a change in density of the magnetic flux. The eddy currents generate Joule's heat in the wafer or conductors in contact with the wafer, and the induced current is used to heat the wafer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

1 is a view for explaining a eddy current caused by a change in the magnetic flux flux.

Referring to FIG. 1, when a magnetic field passing through a conductor changes, an eddy current is induced in the conductor. That is, as shown in Figure 1, by increasing the magnetic field at a right angle to the conductor plate to increase the eddy current to the left to generate a eddy current in the conductor plate to the direction of the magnetic field. The eddy current is formed in the direction of preventing the change of the magnetic field as the vector amount. That is, when the strength and direction of the magnetic field passing through the conductor plate change, eddy currents are generated in a direction that prevents the change.

In general machinery, the eddy current is accepted as an undesirable phenomenon because it absorbs energy to heat the conductor, but the present invention uses induction heating by the eddy current. The induction heating occurs in the conductor and has an advantage of enabling uniform heating without disturbing phenomenon.

2 is a schematic view illustrating a wafer heating system and a method of operating the wafer heating system according to an exemplary embodiment of the present invention. 3 is a cross-sectional view illustrating a wafer heating system according to an exemplary embodiment of the present invention.

2 and 3, a wafer heating system according to a preferred embodiment of the present invention includes a reactor 110 in which a wafer 100 is placed, coils 120 winding the reactor 110, and the coils ( And a generator 130 connected to 120.

The reactor 110 is preferably a quartz furnace or a batch type reactor capable of processing several wafers 100. In this case, the coil 120 is preferably wound around the outer wall of the reactor 110 a plurality of times. The coil 120 is connected to the generator 130 using predetermined electrical connection means. The generator 130 is preferably a radio frequency alternating current generator (RF AC generator). The generator 130, a controller 135 for controlling the operation of the generator 130 may be further attached. The controller 135 is preferably a computer including a user interface.

The generator 130 generates an alternating current under the control of the controller 135. The paths through which the generated alternating current flows are the coils 120 wound around the outer wall of the reactor 110. In this case, the coils 120 form a solenoid, and the current passing through the coils 120 generates a magnetic field inside the reactor 110.

On the other hand, since the current passing through the coil 120 is an alternating current whose magnitude and / or direction changes with time, the density of the magnetic flux flux passing through the reactor 110 continuously changes with time. As such, when the density of the magnetic flux flux changes, a eddy current is generated in the wafer 100 inside the reactor 110 in a direction of preventing the magnetic flux. The eddy current generates Joule's heat proportional to the resistance of the wafer 100 itself.

Induction heating by the eddy current is used to heat the wafer 100. As described in FIG. 1, induction heating by the eddy current makes it possible to uniformly heat the wafer 100 without disturbing phenomenon. In addition, since the induction heating occurs in the conductor, the reactor 110 having a large heat capacity is not heated in the induction heating. Accordingly, the wafer 100 can be heated quickly and uniformly. Likewise, when cooling, the reactor 110 does not need to be cooled, so that cooling can be performed more quickly.

Meanwhile, another embodiment using the conductive plate 140 in contact with the wafer 100 is possible to perform the induction heating more efficiently. 4 shows an embodiment of the present invention using the conductive plate 140 for such efficient induction heating. As shown in FIG. 4, the conductive plate 140 contacts the bottom surface of the wafer 100.

The relationship between the induction heating and the resistance value ρ _c of the conductive plate 140 and the magnitude J of the eddy current is proportional to ρ _c J ² . Therefore, it is desirable to make the conductive plate 140 made of a material having a resistance value for optimizing such a relation and maximizing the magnitude of the eddy current formed therein.

The above-described wafer heating system can form high quality epitaxial layers, especially when applied to molecular layer epitaxy techniques that require rapid control of the temperature of the wafer.

The wafer heating system according to the present invention heats the wafer using induction heating by eddy currents. Accordingly, it is possible to heat uniformly while minimizing unnecessary heating, thereby performing a necessary thermal process while minimizing thermal burden on the wafer. As a result, it can be applied to the production of excellent semiconductor devices. In particular, when applied to the molecular layer epitaxial technique, etc., a high quality epitaxial layer can be formed.

Claims (10)

A reactor in which the wafer is placed; A coil wound around the outer wall of the reactor; And And a generator coupled to the coil. The method of claim 1, The reactor is a wafer heating system, characterized in that the furnace (furnace) type or batch type. The method of claim 1, And at least two coils winding the outer wall of the reactor. The method of claim 1, And a conductor plate in contact with the wafer is further disposed in the reactor. The method of claim 1, And a controller for controlling the operation of the generator. The method of claim 1, The generator is a wafer heating system, characterized in that the radio wave alternator. In the method of operating a wafer heating system comprising a reactor in which a wafer is disposed and a coil wound around the outer wall of the reactor, And operating the wafer by varying the density of the magnetic flux flux generated by the current flowing through the coil. The method of claim 7, wherein The method of changing the density of the magnetic flux flux is a method of operating the wafer heating system, characterized in that for changing the strength and direction of the current flowing through the coil. The method of claim 7, wherein The heating of the wafer is a method of operating a wafer heating system, characterized in that using the eddy current (eddy current) induced by the change in density of the magnetic flux flux. The method of claim 9, The eddy current generates Joule's heat in the wafer or a conductor in contact with the wafer, and the induced current is used to heat the wafer.