JPH01222669A - Thyratron driver - Google Patents

Abstract

PURPOSE:To reduce a jitter at the time of driving a thyratron by providing a DC power source for specifying the peak value of a pulse voltage to be superposed on a reverse bias voltage. CONSTITUTION:A thyratron driver 1 has a pulse generating DC power source 10, a pulse switch 11 for controlling a voltage supplying time from the source 10 on the basis of a firing pulse from a firing pulse generator, and a coupling capacitor 14 for introducing the supplied voltage to be superposed on a reverse bias voltage to the second grid 35 of a thyratron 34. The operation of the driver 1 inputs a firing pulse to the input of a hybrid circuit 12, applies a light source to a photocoupler 12a and switches a MOSFET 13. The supplying voltage of the source 10 is superposed through the capacitor 14 on a reverse bias voltage. This is supplied to the second grid 35. Accordingly the thyratron 34 is turned ON at the same timing to close a high voltage circuit, thereby starting the excitation of an oscillator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thyratron driver for driving a thyratron to control an excimer laser or the like.

[Conventional technology]

In recent years, the use of excimer lasers has rapidly expanded across a wide range of fields, including semiconductor link graphing, medicine, chemical synthesis, nuclear fusion, and uranium enrichment.

Excimer is a molecule that exists only in an excited state, and when this molecule dissociates, it emits ultraviolet pulse light. The oscillation wavelength of this pulse differs depending on the type of encapsulated dregs. (ArF-193w, KrF
248mm, XeCj 308mm)
The operation of the oscillation part of the excimer laser will be explained with reference to FIG. 2. In order to generate the excimer, the inside of the laser tube 20 must be heated with rare gas (Ar, Kr, etc.).

A mixture of Xe), halogen scum (F2. IC, Q), and buffer scum (He, Ne) is filled at 2 to 3 atm, and pre-ionized with ultraviolet rays by discharge in the secondary tl#i ionization cap 21. Then, by high voltage discharge between the main discharge electrodes 22, the rare dregs atoms and halogen atoms are combined in a slightly excited state. In the capacitance transfer type circuit shown in FIG. 2, the energy charged in the storage capacitor C124 is charged into the peaking capacitor 23 through the pre-ionization gap 21 when the thyratron driver CH 25 or rONJ enters the state. As charging progresses and the voltage between the main discharge electrodes 22 reaches a breaktown voltage, discharge begins between the main discharge electrodes 22 and laser oscillation is performed.

The stability of oscillation at this time completely depends on the operational reliability of the thyratron switch 25. Therefore, the operational reliability of the thyratrons and their drivers constituting the thyratrons 1 to 25 is important.

Generally, →Noriratron has an anode, a cathode, and a lid, and the anode has a high voltage (30 to 40 kv).
However, a bias voltage is always applied between the cathode and the grid, and a kind of open high voltage circuit is formed between the anode and the cathode. A thyratron driver is electrically coupled to the grid to determine the timing of operation of the thyratron. In order to ensure the operation of the thyratron switch, the ignition pulse voltage in this thyratron driver is required to rise quickly and accurately in timing.゛As shown in FIG. 3, a conventional thyratron driver of this type includes a DC power supply 30 for pulse generation, a capacitor 31 for charging and discharging the charge supplied from the power supply 30, and a charging and discharging system for the capacitor 31. (SeR switch 32 that determines the timing, and a pulse transformer 33)
It is connected to the second nigerid 35 of the heron 34. S.C.
The R switch 32 operates between a thyristor 32 (a) and a thyristor 32 (a) that operate based on input ignition pulses.
) and a switching transistor 32(b) that performs a switching action based on the operation timing of the switching transistor 32(b).

Now, 1 [/2 S
] width firing pulse is applied, the SCR switch 32
turns "ON" instantaneously, a large anode current passes through the capacitor 31, and as a result, the charge of the capacitor 31, which had been charged to a positive potential during the pulse pause time, is discharged. Since the rapid discharge of the capacitor 31 occurs through the primary winding of the pulse transformer 33, 1.~2 [μ
A positive pulse for driving cylinders l to ron with a width of s] is generated. This output pulse has been stepped up to about 1 [kv], is superimposed on the reverse bias voltage 36, and is supplied to the second nigerid 35 of the cylindrical circuit 34.

As a result, the SIRADO 1 controller 34 is driven and the high voltage circuit is closed.

In this way, conventionally, the SCRC system 32 cannot have a high withstand voltage, so the high voltage system for exciting the oscillation part of the excimer laser and the low voltage system for driving the Zyra 1 to Ron 34 are physically different. Therefore, the pulse transformer 33 becomes indispensable in the configuration of the Sila 1 to Ron switches.

[Problem to be solved by the invention]

However, the conventional Zyratron driver has a problem in that unexpected jitter occurs when the thyristor 32 (a) is turned on or when the pulse transformer 33 is electromagnetic induced. In addition, since the electromagnetic induction effect of pulse 1 to lance 33 is used, the pulse rise time is 150 to 50.
It also had the disadvantage of requiring 0 [nsl.

For this reason, in the past, not only did the laser light output fluctuate, but it was also difficult to shorten the pulse repetition period, and there was a certain limit to the accuracy improvement of this type of laser.

In view of the above-mentioned drawbacks, the technical problem of the present invention is to provide a thyratron switch for controlling an excimer laser, which reduces the jitter that occurs during thyra I-ron driving and significantly shortens the rise time of the driving pulse. It is an object of the present invention to provide a suitable thyratron driver.

[Means to solve the problem]

--6= According to the present invention, there is provided a DC power supply section that specifies the peak value of the pulse voltage superimposed on the reverse bias voltage of the thyratron, and an amplifier circuit that converts the input signal into an electric signal via a photocoupler and amplifies it. A thyratron driver comprising: a switching element that controls the DC power supply section based on an electric signal from the amplifier circuit and shapes the pulse voltage.

is obtained.

Further, according to the present invention, the insulating goo type FET is activated to convert the DC voltage into a pulse voltage, and the converted pulse voltage is applied to the reverse bias voltage of the thyratron via the capacitor. A thyratron driver is obtained which is characterized in that:

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the thyratron driver 1 according to the present embodiment includes a pulse generation DC power supply 10 and a voltage from the power supply 10 based on an ignition pulse input from an ignition pulse generation circuit (not shown). It has a pulse switch 411 that controls the supply time, and a coupling capacitor 14 that superimposes the supplied voltage with a reverse bias voltage and leads it to the second nigerid 35 of the thyratron 34.

Specifically, the pulse generation DC power supply 10 is a power supply that generates a positive polarity DC voltage of a value (approximately 1 [kv]) necessary for driving the thyratron 34, and the pulse generation DC power supply 10 is a power supply that generates a positive polarity DC voltage of a value (approximately 1 [kv]) necessary for driving the thyratron 34.
11. The pulse switch 411 has a photocoupler 21'(a> connected to an ignition pulse generation circuit (not shown) on the input side, and a photocoupler 12' connected to the photocoupler 12 on the output side).
It consists of a transistor amplifier circuit 12 (b) that converts the amount of light emitted from (a,) into a DC voltage and amplifies it, thereby forming a hybrid circuit 12 whose input and output sides are physically separated. This hybrid circuit 12 may use a hybrid IC, which has become popular in recent years.

The pulse switch 411 is a high-speed switching element M
Based on the output signal of the transistor amplifier circuit 12(b) supplied to the gate of the OS-FETI 3, the output voltage of the DC power supply IO supplied to the source thereof is transmitted to the train side. This MOS-FETI 3 is 1[k
V] or higher withstand voltage, and its rise time is 45
It is about [ns]. The drain output of the MOS-FET 13 is superimposed on a reverse bias voltage via a coupling capacitor 14 made up of a Mayer capacitor, for example.

Next, the operation of the Sipe 1 Heron driver 1 according to this embodiment will be explained. First, an ignition pulse is input to the input side of the hybrid circuit 12 to provide a light source to the photocoupler 12(a). Incidentally, the ignition pulse has an amplitude of 5 [V], and its width and repetition period can be arbitrarily selected. The light source is amplified by the transistor amplifier 12(b) and supplied to the gate of the MOS-FET 13. At this time, switching is performed for the rising time of the ignition pulse, and the pulse DC power supply 10 is rO
The state becomes N. The supply voltage of the pulse DC power supply 10 (
lkv) is superimposed with a reverse bias voltage (150v) via the coupling capacitor 14 and is supplied to the second nigerid 35 of the thyratron 34. Therefore, thyratron 34 is
At the same time, it becomes "ON" and closes the high voltage circuit. As a result, excitation of the oscillation section of the excimer laser shown in FIG. 2 is started.

In this way, this embodiment uses a photocoupler to operate based on the hybrid circuit 12 in which the weak current system and the strong current system are physically disconnected, and the output of this hybrid circuit 12. Since a switching element capable of high voltage resistance and high-speed switching is provided, a conventional pulse transformer is no longer necessary. As a result, it has become possible to significantly control the jitter that occurs when driving the thyratron. Furthermore, the MOS-FET used as a switching element is
The rise time is about 45 [ns], and since a mica:1 capacitor is used as the coupling capacitor, the delay due to coupling is less than 1 [ns], compared to the case of using a conventional SCR, switch, and pulse transformer. , the rise time of the drive pulse can now be shortened to 1/3 to 1/10. In terms of cost, the Zyratron drive machine according to this embodiment is less than 1/10 the cost of the conventional one.
It has become a very effective method because it can be achieved by 6.
The application of the cyler 1 to 1':7 driver according to this embodiment is not limited to excimer lasers, and the wavelength value 1 [k, v
], it can be applied to a wide range of fields as a pulse generator with a width of about 1 [μs] and 3.200 PPS.

〔Effect of the invention〕

As explained in section 2 below, according to the present invention, Zyra 1 to 0
In addition to reducing the jitter that occurs when driving the excimer laser, it also significantly shortens the rise time of the driving pulse. We can provide equipment.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the Zyra 1 Heron driver according to the present embodiment, FIG. 2 is a schematic diagram of the oscillation part of the Zyratron Ii1 according to the present embodiment, and
The figure shows a configuration diagram of a conventional → novi drive Heron driver. 1l- 1... Siler 1 to Ron driver, ]0... Pulse DC power supply, 11... Valse switch, 12... High frit circuit, 1.2 (a)... Between f 1~Coupler, 1.2(b)...Transistor amplifier circuit, 13...
・MOS-F”ET, 14...Coupling capacitor.

Claims (3)

[Claims] 1. A DC power supply unit that specifies the peak value of the pulse voltage that is superimposed on the reverse bias voltage of the thyratron, an amplifier circuit that converts the input signal into an electric signal via a photocoupler and amplifies it, and an electric signal based on the electric signal from the amplifier circuit. and a switching element that controls the DC power supply section and shapes the pulse voltage. 2. In the thyratron driver according to the first claim,
A thyratron driver, wherein the switching element is an insulated gate FET. 3. A thyratron driver characterized in that an insulated gate FET is operated to convert a DC voltage into a pulse voltage, and the converted pulse voltage is applied to a reverse bias voltage of a thyratron via a capacitor.