JPH088385B2 - Excimer laser device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excimer laser device using an automatic preionization capacity transfer type discharge excitation method.

[0002]

2. Description of the Related Art FIG. 2 shows an excimer laser device of a conventional example. Discharge by turning on. Due to the discharge current I1 due to this discharge, electric charges are transferred to the capacitor C2 and pulse charging is performed.

Since this pulse charging is carried out via the preionization PI pin, an arc discharge is caused between the preionization pins PI, whereby ultraviolet ray preionization is automatically carried out. When the capacitor C2 completes charging, the magnetic switch MS, which is a saturable reactor, saturates and the discharge current I
2 flows and a main discharge is generated between the main electrodes ME1 and ME2.

By the way, in such a structure, the main electrode ME1 remains in the coil L until the magnetic switch MS is saturated.
Since it is set to the ground potential via 12, almost the entire charging voltage of the capacitor C2 is applied to the magnetic switch MS. Since the magnetic switch MS is not saturated until the charging of the capacitor C2 is completed, a core having a large cross-sectional area is required.

Further, a potential difference corresponding to almost the entire charging voltage of the capacitor C2 is generated between the main electrodes ME1 and ME2 and the preionization pin PI until the magnetic switch MS is saturated. On the other hand, since the main electrodes ME1 and ME2 and the preionization pin PI need to be installed at positions close to each other, when such a large potential difference occurs, there is a drawback that insulation design between them becomes difficult.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to an excimer laser device adopting a discharge excitation system of a preliminary automatic ionization capacity transfer type, and a magnetic switch used for suppressing discharge between main electrodes until capacity transfer. Along with miniaturization,
The purpose is to simplify the insulation design of the preionization pins.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a main discharge circuit consisting of a series circuit of a magnetic switch and a main electrode for discharging excimer laser excitation is connected across a capacitor whose capacity is transferred by pulse charging, and A preionization pin circuit in which preionization pins are connected in series between a pair of voltage dividing capacitors is connected across the capacitors, and one of the preionization pins is connected to one of the main electrodes.

When the capacitor is pulse-charged, a part of the charging current flows to the preionization pin, and arc discharge is generated at the preionization pin to perform preionization. Further, since the preionization pin is connected between both voltage dividing capacitors, the potential thereof is a value (0 to 0) determined by the ratio of the voltage dividing capacitors.
Between the charging voltage). Since one of the main electrodes is connected to the preliminary ionization pin and has the same potential, the potential of the main electrode also takes a value between 0 and the charging voltage.

Since the potential of the main electrode becomes low, a voltage lower than the charging voltage is applied to the magnetic switch. This eliminates the need for large cross-section magnetic switches that are unsaturated until the capacitor is pulse charged. Since the preliminary ionization pin and the main electrode have the same potential, insulation design between them becomes easy.

[0010]

EXAMPLE FIG. 1 shows an example of the present invention. In addition, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts. According to the present invention, a main discharge circuit including a series circuit of the magnetic switch MS and the pair of main electrodes ME1 and ME2 is formed across the capacitor C2 whose capacity is transferred by pulse charging.

A pair of voltage dividing capacitors CP1 and CP2
To prepare a preionization pin circuit in which the preionization pin PI is connected between both capacitors. Then, this preionization pin circuit is connected across the capacitor C2. Further, one of the preionization pins PI is connected to the main electrode ME1 so that a part of the charging current I1 ′ when the capacitor C2 is pulse-charged flows to the preionization pin circuit.

When charging of the capacitor C1 is completed,
The high-speed switching element SW is turned on and discharged, and the electric charge is transferred to the capacitor C2. Capacitor C at this time
Part of the pulse charge current of 2 flows to the preionization pin circuit,
Pre-ionization is performed here.

In this case, both voltage dividing capacitors CP1 and CP
Assuming that the capacitances of 2 are set to be substantially equal, the potential of the preionization pin PI is almost half of the charging voltage of the capacitor C2. When the transfer of charge to the capacitor C2 is completed,
The magnetic switch is saturated, the discharge current I2 flows, discharge is generated between the main electrodes, and laser excitation is performed as in the conventional configuration.

However, as described above, the potential of the preionization pin PI is almost half the charging voltage of the capacitor C2, and one of the preionization pins PI and the main electrode ME1 have the same potential, so that both ends of the magnetic switch MS are connected. The voltage applied to is also about half the charging voltage of the capacitor C2. That is, the cross-sectional area of the core required for the magnetic switch MS is almost half by half that of the conventional configuration, and the size can be reduced accordingly.

Further, since the preliminary ionization pin PI and the main electrode ME1 have the same potential, the insulation design between them is easier than that of the conventional configuration, and a highly reliable device can be designed.

Although the capacitances of the voltage dividing capacitors CP1 and CP2 are substantially the same in the above-mentioned example, the capacitances are not limited to this, and the ratio of the two capacitances is set within the optimum range for downsizing the magnetic switch MS. Just set it. For example, the capacitance of the voltage dividing capacitor CP1 may be set within a range of half or twice the capacitance of the voltage dividing capacitor CP2.

[0017]

As described above in detail, according to the present invention, in an excimer laser device adopting a discharge excitation method of a preliminary automatic ionization capacity transfer type, it is used for suppressing discharge between main electrodes until capacity transfer. The magnetic switch can be manufactured in a small size, and the insulation design of the preionization pins can be simplified.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional example.

[Explanation of symbols]

 C2 Capacitor MS Magnetic switch ME1 Main electrode ME2 Main electrode PI Pre-ionization pin CP1 voltage dividing capacitor CP2 voltage dividing capacitor

Claims (1)

[Claims] 1. A main discharge circuit consisting of a series circuit of a magnetic switch and a main electrode for discharging by excimer laser excitation is connected across a capacitor whose capacity is transferred by pulse charging, and a spare is provided between a pair of voltage dividing capacitors. Straighten the ionization pin
An excimer laser device in which a preionization pin circuit connected to a column is connected across the capacitor, and one of the preionization pins is connected to one of the main electrodes.