TW201337031A - Apparatus and method for applying a voltage across a plurality of silicon rods in a CVD-reactor - Google Patents

Abstract

An Apparatus and method for applying a voltage across a plurality of silicon rods in a CVD-reactor are provided. The outputs of the second transformers of the second current supply unit are each connected with the several silicon rods in the series connection. The number of the several silicon rods is at least the same with the number of the silicon rods connected with each of the first transformers of the first current supply. The third current supply unit comprises outputs which are parallel to the first and second transformers. The short circuit device includes a line connecting the outer ends of the series connection, in which at least one resistor or the secondary side of a transformer and a switch is provided. The control unit is connected to at least an ammeter for measuring a flow of current through the resistor or to a voltmeter for measuring a voltage at the primary side of the transformer.

Description

Apparatus for applying voltage to each core in a CVD reactor and method thereof

The present invention relates to a method and apparatus for applying a voltage to a plurality of tantalum or parallel tantalum rods in a CVD reactor.

In the field of semiconductor and photovoltaic technology, for example, in accordance with the method provided by Siemens, a high purity silicon rod is produced in a deposition reactor (also known as a CVD reactor). To this end, a thin silicon rod is first placed in the reactor and then deposited on the thin rod in the deposition process. During this process, the thin tamper is housed in clamping and contacting devices that maintain the desired orientation of the thin tamper while achieving electrical contact. Typically, every two thin tantalum rods are connected to each other at their free ends through a conductive bridge to form an electrical circuit by contacts located on the same side of the reactor. However, it is also possible to make electrical contact at the opposite ends of the thin rods, ie from above and below, in order to pass current through the thin rods. For the sake of brevity, either a pair of thin tantalum rods connected by a conductive bridge or a thin tantalum rod that is in contact at the opposite end, hereinafter referred to as a pry bar.

The enthalpy deposition temperature in the CVD reactor is about 1000 ° C, which is mainly used The resistance heating device of the crowbar is heated accordingly. However, considering the characteristics of yttrium as a negative temperature coefficient thermistor, it is necessary to first convert the bismuth rod into a conductive state at the beginning of the process. At this point, you need to consider the two parameters of voltage and temperature. The conductivity of germanium increases exponentially with increasing temperature. The resistor thus formed is fed with a power of P = U * U / R, which causes the temperature to rise. The increase in temperature causes the resistance to drop, causing further temperature rise. At the end of the process, the voltage must be reduced to prevent the rod from melting.

The crowbar initially has a higher resistance for the above reasons and the resistance decreases with increasing temperature, so it is necessary to first apply a higher initial voltage to the crowbar to induce an initial current, which is also referred to as crowbar ignition. After the initial heating is achieved by the current and the reduced resistance of the pry bar, the voltage can be reduced to the operating voltage. The temperature adjustment of the crowbar can then be further controlled primarily by current control.

In addition to this, the heating of the crucible rod can be further provided, in particular at the beginning of the heating, for example by preheating with a peripheral heating element or by preheating with a cooling medium in the reaction vessel jacket. Since these heating methods cause differences in the temperature of the crowbar, it is necessary to use other ignition voltages. Next, only the heating achieved with the cooling water is taken into consideration, since this heating method requires a higher voltage, that is, medium voltage ignition is required.

For example, the thin crucible rod is heated to about 130 ° C to 160 ° C with cooling water of the reaction vessel to achieve medium pressure ignition. The cooling effect of the cooling water on the electrode and the lower part of the thin rod is minimized. However, since the resistance of the crowbar at these temperatures is high, it is necessary to apply a voltage of 5 kV < U < 20 kV to each crowbar pair to achieve ignition.

A special ignition transformer is used to achieve high voltage. Ignition transformer Single or multi-stage solutions are available. Figure 1 is a schematic diagram of a two-stage solution (including transformer sets T1 and T2). For example, the controller described in DE 10 2010 020 740 A, DE 20 2004 014 812 A, US Pat. No. 7,279,811 A, or DE 20 2009 003 325 A can be used to reduce the voltage on the crowbar after ignition is completed. The choke described in DE 10 2010 020 740 A, which is hereby incorporated by reference in its entirety in its entirety, in its entirety, the disclosure of which is hereby incorporated by reference.

In particular, DE 10 2010 020 740 A, which is hereby incorporated by reference, describes a device and a method for the stepwise application of different voltages to thin sputum rods in a CVD reactor. The device described in the present case has a circuit in which a plurality of crowbars (usually pairs of crowbars) serving as resistors can be inserted in series; and a first one for applying different voltages to each of the crowbars in the series circuit Second and third current supply units. The first and second current supply units have a plurality of transformers. The first current supply unit is configured such that each of the crowbars (crowbar pairs) is assigned a transformer having a first open circuit voltage and a first short circuit current. The second current supply unit is configured to distribute a transformer having a second open circuit voltage and a second short circuit current for each of the two crowbars (the pair of crowbars), wherein the second open circuit voltage is lower than the first open circuit voltage, and the second short circuit The current is higher than the first short circuit current. The third current supply unit has a terminal connected to an end of the series circuit of the crowbar, wherein the third current supply unit is configured to provide a short circuit current higher than the second transformer in a voltage range lower than an open circuit voltage of the second transformer Current.

If current flows through the transformer of the first current supply unit, and the corresponding choke limits the voltage, it switches to the second current supply unit. A choke connected to the second current supply unit limits the current and causes the voltage on the secondary side to decrease again Thereafter, it is switchable to the thyristor controller of the third current supply unit.

In order to provide overvoltage protection for the third current supply unit, in particular its thyristor controller, it has heretofore been practiced to embed a grounding switch when applying voltages by the first and second current supply units so as to be at the end of the series circuit The upper rod is grounded. Since a circular connection or mesh (mesh, 4 crowbar pairs + ground connection) is then closed, the change in the secondary voltage of the transformer causes other secondary voltages to change. These voltages are limited by the choke to 25% of the open circuit voltage, so that the voltage on the rods that are not electrically conductive (the rods are usually not fired at the same time, but one after the other) is not enough to achieve a conductive state. Current is still flowing through the transformers that are not yet electrically conductive because current flows through other conductive rods and shorting devices. It can be seen that this configuration scheme has the danger that not all the crowbars can ignite, thereby affecting the deposition process.

In view of the above, it is an object of the present invention to provide an apparatus and method for igniting individual rods in a CVD reactor that reliably ignites all of the rods in a simple and economical manner.

The solution to achieve the above object of the present invention is the device described in claim 1 and the method described in claim 8 of the patent application. Other designs of the invention are referred to the dependent items.

In particular, the means for applying a voltage to a plurality of crowbars in a CVD reactor has a series circuit in which a plurality of pluton rods can be inserted as resistors. road. The device further includes at least one first current supply unit, at least one second current supply unit, at least one third current supply unit, at least one short circuit device, and at least one for controlling the first, second and third current supplies The unit and the control unit that can control the short circuit device. The shorting device is adapted to connect and ground the outer ends of the series circuit in a controlled manner. The first current supply unit has a plurality of first transformers, and the output ends of the first transformers are respectively connected to at least one rod of the series circuit. The second current supply unit has a plurality of second transformers, and the output ends of the second transformers are respectively connected to a plurality of crowbars in the series circuit, and the crowbars connected by the output ends of the second transformers And the number is at least equal to the number of crowbars respectively connected to the respective output ends of the first transformers, and the output ends of the second transformers are connected in parallel with the output terminals of the one or more of the first transformers Connected to the crowbars in the series circuit. The third current supply unit has an output connected to the tandem rods, and the outputs of the third current supply unit are connected in parallel with the first and second transformers. The shorting device has a line connecting the outer ends of the series circuit, the circuit is provided with at least one resistor, or a secondary side of a transformer, and at least one switch is provided. The control unit is coupled to at least one ammeter for measuring the current flowing through the resistor or a voltmeter for measuring the voltage on the primary side of the transformer. As mentioned previously, the device can achieve medium pressure ignition for the crowbar. The provision of a secondary side of the resistor or transformer prevents a simple mesh connection of the pry bar through the line of the shorting device and causes problems in the course of operation. The ignition state of the rods can be known by current measurement or voltage measurement.

Compared with the first transformers, the second transformers are preferably separately and more A large number or a double number of crowbars are connected in series. Thereby, the number of transformers in the second current supply unit can be made smaller than the number of transformers in the first current supply unit, and the cost of the second voltage supply device can be reduced and/or the volume thereof can be reduced. In addition, the output of the third current supply unit is preferably connected to the outer end of the series circuit of the rods through the thyristor controller.

To simplify the necessary protection techniques, the first and/or second transformers in series with adjacent masts are reverse wound. This allows the outer ends of the tandem rods to be at a potential.

According to a preferred embodiment, the steepness of the current-voltage characteristic curve of the transformer of the first current supply unit is greater than the transformer of the second current supply unit, and the steepness of the current-voltage characteristic curve of the transformer of the second current supply unit Greater than the third current supply unit. This makes it easy to adjust the temperature-dependent resistance changes of the pry bar. That is, the specific resistance of the crowbar first drops rapidly with increasing temperature, and then shifts to saturation. The different current-voltage characteristics of the current supply units reflect the above conditions by their different distributions.

To prevent overloading of the current supply units, the control unit is capable of switching between the current supply units based on current flowing through the first or second transformers and possibly through the resistors. Thereby, switching between different voltages as needed is simply achieved, wherein the current flowing through the resistor can indicate the ignition state of the crowbar.

In an embodiment equipped with a transformer, the control unit is capable of applying a voltage to the primary side of the transformer based on the voltage on the primary side of the transformer. Take this The asymmetry in the line can be compensated to help ignite the rods.

According to a method for applying a voltage to a plurality of tandem rods in a CVD reactor, a plurality of first transformers are used to apply a first voltage to the crucible rod, and a plurality of second transformers are used to apply a second voltage to the crucible rod, wherein the The two voltages are lower than the first voltage, and a third voltage is applied to the rods by a current supply unit, and the third voltage is lower than the second voltage. During the application of the first and the second voltage, the outer ends of the series circuit formed by the crowbars are connected by a circuit provided with a resistor or a secondary side of the transformer, and are connected by a switch The ground can be turned off to measure the current flowing through the resistor or the voltage on the primary side of the transformer. The application of such different voltages is at least partially affected by the measurements. The term "first voltage" as used herein refers to the average effective value measured over the period of time during which the voltage is applied by the first transformer. The second voltage is used herein to mean the average effective value measured during the period in which the voltage is applied by the second transformer. As the crowbars heat up, the current induced by the first voltage and/or the second voltage can cause the voltage to drop over the entire time period and the current rises. The third voltage is used herein to refer to the average effective value measured during the period in which the voltage is applied by the current supply unit. As the crowbars heat up, the voltage may drop over the entire time period and the current may continue to rise.

The method can achieve reliable medium voltage ignition and achieve temperature rise in the deposition reactor by resistance heating of the crucible rod. A resistor or transformer disposed in a line connecting the outer ends of the series circuit formed by the crowbars prevents a simple mesh connection phenomenon and related problems such as individual crowbar points. The fire failed.

Preferably, the third voltage is applied to all of the tandem rods, and the first and/or second voltages are applied to the individual or groups of the rods. The first voltage can be applied to each of the rods, and the second voltage can be applied to the two tantalum rods in series.

To prevent overloading of the first and second transformers, currents flowing through the bars are measured and at least one switching operation between different voltages is controlled based on the measured current.

In an embodiment equipped with a transformer, a voltage is applied to the primary side of the transformer based on the measured voltage on the primary side of the transformer to compensate for the asymmetry.

A different number of tantalum rods in series can be configured in the deposition reactor. The aforementioned circuits can also be used in multiple applications in the reactor.

1‧‧‧矽棒对

3‧‧‧ Thin rod

4‧‧‧Connected Bridge

6‧‧‧Electrode mechanism

7‧‧‧ bottom

10‧‧‧Circuit layout/device

12‧‧‧First current supply unit

14‧‧‧Second current supply unit / second current supply device

16‧‧‧ Third current supply unit / third current supply device

21‧‧‧Transformers

22‧‧‧Transformers

23‧‧‧Transformers

24‧‧‧Transformers

26‧‧‧Current

27‧‧‧Current

28‧‧‧Current

29‧‧‧Current

31‧‧‧Transformers

32‧‧‧Transformers

34‧‧‧Current

35‧‧‧Current

40‧‧‧Short device

42‧‧‧ lines

44‧‧‧Resistors

46‧‧‧Ammonia

48‧‧‧First switch

49‧‧‧Second switch

54‧‧‧Transformers

56‧‧ voltmeter

58‧‧‧Double switch

S1‧‧‧矽棒

S2‧‧‧矽

S3‧‧‧矽

S4‧‧‧矽

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of a crowbar pair arrangement in a CVD reactor, with and without deposition of germanium.

Figure 2 is a schematic illustration of a circuit layout for applying different voltages to a crucible in a CVD reactor.

Figure 3 is a graph of current-voltage characteristics of the different current supply units shown in Figure 2, showing typical current-voltage variations of a rod in a CVD reactor prior to the onset of tantalum deposition.

4 is a schematic illustration of an alternate circuit layout for applying different voltages to a crucible in a CVD reactor.

The invention will now be described with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view schematically showing a configuration of a pair of crowbars in a CVD reactor. For the sake of clarity, only two pairs of crowbars 1 are shown side by side in the same plane. A CVD reactor can accommodate a plurality of such pairs of crucible rods, and the pair of crucible rods may also be oppositely disposed in a plane. There are usually four to twenty-four such pairs of pry bars in a CVD reactor. Of course, the number of crowbar pairs 1 can also be increased or decreased.

The two pairs of rods 1 shown in Fig. 1 are composed of two thin rods 3 and a connecting bridge 4. The crowbar pair on the right in Figure 1 is in an initial configuration before vapor deposition. The left scorpion pair is in a configuration after the vapor deposition of the ruthenium into the thin ruthenium rod, which is indicated by a broken line in the left 矽 rod pair.

These thin tantalum rods are disposed in the electrode mechanism 6 on the bottom 7 of the CVD reactor in a conventional manner. The connecting bridges 4 of the pair of crowbars 1 connect the free ends of the thin crowbars 3 together. The connecting bridges 4 are likewise constructed of tantalum and preferably have electrical properties such as the thin tantalum bars 3. In particular, the connecting bridges 4 can be made of thin tantalum rods and connected in a suitable manner to the free ends of the thin pry bars 3 arranged in the arrangement shown in FIG.

Based on such a pry bar pairing arrangement, the electrical contact of the thin pry bar 3 can be achieved only by the electrode mechanism 6 on the bottom 7 of the CVD reactor. For ease of description As described above, the pair of crowbars shown in Fig. 1 or the thin crowbars to which the electrodes are connected at both ends are hereinafter referred to as crowbars.

2 is a schematic illustration of a circuit layout 10 for applying different voltages to the crucible bars S1 through S4, which may be disposed in a CVD reactor not shown in the manner shown in FIG.

The circuit layout 10 shown in FIG. 2 is used for four crowbars S1 to S4, and can also be used for not four crowbars. Currently, the number of crowbars in a single circuit layout 10 is preferably four, several times four or six. One, or several times six. Thus, a corresponding number of circuit layouts 10 can be provided depending on the number of crowbars in the CVD reactor. The rods S1 to S4 are connected in series to each other.

The circuit layout 10 has a first current supply unit 12, a second current supply unit 14, a third current supply unit 16, and a control unit not shown.

The first current supply unit 12 is composed of a total of four transformers 21 to 24, and the primary side of the transformers can be connected to a single-phase AC voltage of, for example, 400 volts by means of respective chokes 26 to 29 and switches not shown. The transformers 21 to 24 have on their secondary sides an open circuit voltage of, for example, about 8000 volts and a short circuit current of, for example, about six amps. FIG. 3 shows an exemplary current-voltage characteristic diagram K1 of the transformers 21 to 24. As shown in the figure, the transformers 21 to 24 all have a sharply decreasing current-voltage characteristic curve, that is, the voltage on the secondary side rapidly decreases as the current increases. The medium voltage ignition voltage is usually 5 KV to 20 KV.

Each of the transformers 21 to 24 is assigned to one of the rods S1 to S4, and the output terminals on the secondary side of the transformers 21 to 24 are respectively connected to the opposite ends of one of the rods S1 to S4. Therefore, each of the transformers 21 to 24 can pass through the series A bar of the rods S1 to S4 applies a voltage of about 8000 volts. Wherein, the secondary windings of the transformers 21 and 23 are reversely wound with respect to the secondary windings of the transformers 22 and 24, such that the transformers 22 and 24 and the primary side of the primary side and the secondary side of the series tantalum rod are reversely wound. The secondary side reverse wound transformers 21 and 23 alternately appear. Specifically, the transformers 21 to 24 are wound in some manner and connected to the crowbars S1 to S4 so that when the voltages are applied to the crowbars S1 to S4 through the transformers 21 to 24, the crowbars S1 and S4 are connected in series to each other. The outer ends are at the lowest level.

The second current supply unit 14 is formed by two transformers 31, 32, the primary side of which can be connected to a single-phase AC voltage of, for example, 400 volts by means of respective chokes 34, 35 and switches not shown. The transformers 31, 32 have on their secondary side an open circuit voltage of, for example, about 4000 volts and a short circuit current of, for example, twenty amps. FIG. 3 shows a current-voltage characteristic diagram K2 of the transformers 31, 32. As shown, the current-voltage characteristic curves of the transformers 31, 32 are less steep than the transformers 21 to 24 of the first current supply unit 12.

Each of the transformers 31, 32 is assigned two of the crowbars S1 to S4, and the output ends on the secondary side of the transformers 31, 32 are respectively connected to the adjacent crowbars of the tandem rods S1 to S4. The opposite ends of a set of crowbars are connected. Therefore, each of the transformers 31, 32 can apply a voltage of about 2000 volts through one of the tandem rods S1 to S4 (the tandem rods are mainly used as a reactor). Among them, the secondary sides of the transformers 31, 32 are reversely wound. Specifically, the transformers 31, 32 are wound in some manner and connected to the boring bars S1 to S4 such that when voltages are applied to the boring bars S1 to S4 through the transformers 31, 32, the series of stalks S1 and S4 are connected. Outer end They are all at the lowest size.

The third current supply unit 16 is any controllable short-circuit current that can lower the open circuit voltage of the transformers 31, 32 of the second current supply unit 14 and cause the current to be higher than the transformers 31, 32 of the second current supply unit 14. Current supply device. In this embodiment, the third current supply unit 16 can, for example, set the voltage at its output to 2500 volts to 50 volts and the current to 10 amps to 3400 amps, for example, with a thyristor controller. And turning off the third current supply unit. FIG. 3 shows a current-voltage characteristic diagram K3 of the third current supply device 16. As shown, the steepness of the current-voltage characteristic of the third current supply device is less than the transformer of the second current supply device 14.

The third current supply device is connected to the tandem rods S1, S2, S3, and S4 in a manner such that the voltage of the third current supply device decreases along the tandem rods S1 to S4, that is, The third current supply device is connected to the outer ends of the crowbars S1 to S4 of the crowbars connected in series.

The outer ends of the rods S1 to S4 are connected by a short-circuiting device 40. The short circuit device has a line 42, a resistor 44, an ammeter 46, a first switch 48, and a second switch 49. The first switch can be coupled to the second switch.

Line 42 connects the outer ends of the rods S1 to S4 together. Resistor 44 is in series with ammeter 46 in line 42. Switch 48 employs a configuration that can open or close line 42 with switch 49 disposed between the shorted line and ground to achieve grounding.

The unillustrated control device is adapted to transmit the first, second and third electricity The flow supply units 12, 14 and 16 sequentially and selectively apply voltages to the rods S1 to S4. The transformers 21 to 24 of the first current supply unit 12 and the transformers 31, 32 of the second current supply unit 14 can be turned on and off individually, in groups or together. Furthermore, the control device is capable of manipulating the shorting device during operation of the first and second current supply units 12, 14 (i.e., closing or opening the switches 48, 49), thereby placing the crowbars S1 to S4 The outer end is grounded. This can achieve the purpose of providing protection for the third current supply unit.

In the case of medium voltage ignition, in particular, a voltage is first applied to the transformers 21 to 24 of the first current supply unit 12. If current flows through the transformers 21 to 24 of the first current supply unit 12 and the respective chokes 36 to 29 limit the voltage, the switches are switched to the transformers 31, 32 of the second current supply unit 14. The chokes 34, 35 connected to the transformers limit the current and cause the voltage on the secondary side to decrease again, and then switch to the thyristor controller of the third current supply unit 16. The shorting device is closed during operation of the first and second current supply units 12, 14 and is open when the third current supply unit is operating. The short-circuiting device can also be disconnected during operation of the second current supply unit 14.

Resistor 44 in line 42 prevents a simple mesh connection from occurring through masts S1 through S4 and line 42. Otherwise, such mesh grounding may prevent all of the crowbars S1 to S4 from reliably igniting because changes in the secondary voltage of one transformer cause other secondary voltages to change. Such changes occur, for example, due to the ignition of one of the rods S1 to S4. However, these voltages are limited by the choke to 25% of the open circuit voltage, so the voltage on the crowbar is not yet conductive or Not enough to achieve the conductive state of the corresponding crowbar. Current is still flowing through the transformers that are not yet electrically conductive because current flows through other conductive rods and shorting devices.

The resistor 44 in the line 42 solves the above problem, wherein the resistor is limited to a voltage that does not exceed the allowable voltage of the thyristor controller of the third current supply unit. The ammeter 46 is used to monitor the current flowing through the shorting device 40, whereby it is possible to check whether the ignition is successfully applied to all of the crowbars S1 to S4. Otherwise, there is a danger that the sluice fluid controller will be over-voltage due to the disconnection of the short-circuit device (the transformer cannot be driven by the unfired squib) (the transformer is in an unloaded state), which may cause serious material loss.

4 is a schematic diagram of an alternative circuit layout 10 for applying different voltages to the boring bars S1 to S4, wherein the same or similar elements in FIG. 4 as in FIG. 2 use the same component symbols.

The circuit layout 10 also has a first current supply unit 12, a second current supply unit 14, a third current supply unit 16, a short circuit device 40, and a control unit not shown. The alternative circuit layout 10 shown in FIG. 4 is identical to the circuit layout shown in FIG. 2 except for the short circuit device 40. To avoid repetition, the first to third current supply units 12, 14, and 16 herein refer to the previous related description.

In the embodiment shown in FIG. 4, the short circuit device has a line 42, a transformer 54, a voltmeter 56, a first switch 48, and a second switch 49. Line 42 also connects the outer ends of the rods S1 to S4 together, with the secondary side of transformer 54 being arranged in series in line 42. Performing a primary side voltage measurement on the transformer 54 (here a dual weight measurement is performed so that a path can always be measured in a manner independent of the supply voltage), The current is caused to cause a voltage drop to be recorded in a positive direction or a negative direction.

Subsequently, the transformer can operate in the short-circuiting device 42 in the forward or reverse direction according to the measurement to compensate for the asymmetrical condition. This can be achieved by using dual switches 58 (independent switching contacts that can be latched to each other) that connect the primary side terminal of transformer 54 with a single phase alternating voltage of, for example, 400 volts.

This load-independent additional voltage can assist in the ignition characteristics during operation of the first and second current supply units 12, 14. At the same time, a maximum voltage that prevents damage to the thyristor controller of the third current supply unit can also be defined.

Compensating for the asymmetry at the end of operation of the first current supply unit 12 requires a different, generally smaller, voltage than compensating for the asymmetry during operation of the second current supply unit 14. This can be compensated for by the transformer 54 having a number of voltage tap-offs that are also bipolarly turnable. As an alternative, the primary voltage of the additional transformer can also be adjusted.

The present invention has been described in detail by way of preferred embodiments thereof, and the invention is not limited to the specific embodiments described above. In particular, the present invention is not limited to the numerical values given in terms of the number of components, voltage values, and current values.

1‧‧‧矽棒对

3‧‧‧ Thin rod

4‧‧‧Connected Bridge

6‧‧‧Electrode mechanism

7‧‧‧ bottom

Claims (12)

A device (10) for applying a voltage to a plurality of crowbars (S1 to S4) in a CVD reactor, comprising: a series circuit, the crowbars (S1 to S4) being insertable as a resistor into the series circuit; at least one a first current supply unit (12); at least a second current supply unit (14); at least a third current supply unit (16); at least one short circuit device (40) adapted to be controlled in a controlled manner The outer ends of the series circuit are connected and grounded; and at least one control unit is configured to control the first current supply unit, the second current supply unit and the third current supply unit (12, 14, 16) and the short circuit device (40), wherein the first current supply unit (12) has a plurality of first transformers (21 to 24), and each of the output terminals of the first transformers is respectively connected to at least one of the crowbars (S1 to S4) a connection, wherein the second current supply unit (14) has a plurality of second transformers (31, 32), each of the output terminals of the second transformers being respectively connected to a plurality of crowbars in the series circuit, The number of the crowbars connected to the respective outputs of the second transformer is at least equal to The number of the crowbars (S1 to S4) respectively connected to the respective outputs of the first transformers (21 to 24), and the outputs of the second transformers are associated with one or more of the first transformers (S1 to S4) The output terminals are connected in parallel to the crowbars in the series circuit, wherein the third current supply unit (16) has an output connected to the series circuit, and the output of the third current supply unit is The first transformer and the second transformers are connected in parallel, Wherein the short circuit device (40) has a line connecting the outer ends of the series circuit, wherein the circuit is provided with at least one resistor (44), or a secondary side of a transformer (54), and at least one switch (48) And the control unit and at least one ammeter (46) for measuring the current flowing through the resistor (44) or a voltmeter for measuring the voltage on the primary side of the transformer (54) (56) )connection. The apparatus for applying a voltage to a plurality of crowbars in a CVD reactor as described in claim 1 is characterized in that the second transformers (31) are compared with the first transformers (21 to 24). , 32) are respectively connected in series with a larger number or a double number of the crowbars (S1 to S4). The apparatus for applying a voltage to a plurality of crowbars in a CVD reactor according to any one of the preceding claims, wherein the output end of the third current supply unit passes through the thyristor controller and the crowbars The series circuit of (S1 to S4) is connected. A device for applying a voltage to a plurality of crowbars in a CVD reactor according to any one of the preceding claims, characterized in that the first and/or the plurality of crowbars are connected in series with the adjacent crowbars The second transformer is reverse wound. A device for applying a voltage to a plurality of crowbars in a CVD reactor according to any one of the preceding claims, characterized in that the steepness of the current-voltage characteristic of the first current supply unit is greater than the second The current supply unit has a steeper current-voltage characteristic of the second current supply unit than the third current supply unit. A device for applying a voltage to a plurality of crowbars in a CVD reactor according to any one of the preceding claims, wherein the control unit is capable of flowing through the first transformers or the second transformers And a current that may flow through the resistor (44) switches between the first to the third current supply units. A device for applying a voltage to a plurality of crowbars in a CVD reactor according to any one of the preceding claims, wherein the control unit is capable of determining a measured voltage on a primary side of the transformer (54). Apply voltage to the primary side of the transformer. A method of applying a voltage to a plurality of tandem rods in a CVD reactor, comprising the steps of: sequentially applying a first voltage to the plurality of first rods to the plurality of rods; and applying a second voltage by using the plurality of second transformers Giving the crowbars, wherein the second voltage is lower than the first voltage; and applying a third voltage to the crowbars by using a current supply unit, wherein the third voltage is lower than the second voltage, and is applied In the first and the second voltage process, the outer ends of the series circuit formed by the crowbars are connected and grounded by a resistor or a line provided with a secondary side of a transformer, and the current flows through the The current of the resistor or the voltage on the primary side of the transformer is measured and, at least in part, the measured voltage is applied to the different voltages applied. A method of applying a voltage to a plurality of tandem crowbars in a CVD reactor as described in claim 8 is characterized in that the third voltage is applied to all of the tantalum rods connected in series. A method of applying a voltage to a plurality of tandem crowbars in a CVD reactor as described in claim 8 or claim 9, wherein the first voltage is applied to each of the crowbars, The second voltage is applied to the two tantalum rods in series. A method of applying a voltage to a plurality of tandem crowbars in a CVD reactor as described in any one of claims 8 to 10, characterized in that The current flowing through the crowbars is measured, and switching between different voltages is controlled based, at least in part, on the measured current. A method of applying a voltage to a plurality of tandem rods in a CVD reactor according to any one of claims 8 to 11, wherein a voltage is applied according to the measured voltage on the primary side of the transformer. The primary side of the transformer compensates for the asymmetry in the line.