JPH1174591A - Pulse gas laser oscillator and laser annealing device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise stability of laser energy especially for each pulse at a pulse gas laser oscillation device. SOLUTION: The pulse gas laser oscillation device comprises a vessel in which an excitation gas is sealed up, main discharge electrodes 11 provided facing each other in the vessel, a pre-ionization electrode 9 for discharge with the main discharge electrode 11 for pre-ionization, a charge/discharge circuit provided with a main capacitor 3 for charging/discharging an electric power to be supplied between each electrode 11, a power source for supplying the electric power to the charge/discharge circuit, peaking capacitors 7a and 7b in which, connected in parallel to a pair of main discharge electrodes 11, the electric power from the main capacitor 3 is accumulated, and an optical resonator for amplifying the light generated at the main discharge electrode 11. Here, a circuit which connects the main capacitor 3 to the peaking capacitors 7a and 7b is branched into the one resorting to the pre-ionization electrode 9 and the one not resorting to it, while at least one circuit is connected to oversaturation reactors 12a and 12b for raising stability in laser energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulsed gas laser oscillator, and more particularly to a technique for improving the stability of laser energy for each pulse and extending the life of the apparatus, and a laser annealing apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, pulse gas laser oscillation devices such as excimer lasers often use an automatic ultraviolet pre-ionization method as shown in FIG. In these circuits, a charging resistor 2, a main capacitor 3, and a floating inductance 4 are generally connected in series with a DC power supply 1. The DC power supply 1 is connected in parallel with a preionization electrode 9 and a main discharge electrode 11 to which a high-voltage switching element (thyratron) 5, a charging reactor 6, and a peaking capacitor 7 are connected. This main discharge electrode 1
1 has a gap 10 between the main discharge electrodes and faces each other.

[0003] In this state, the time from the ignition between the preliminary ionization electrodes 9 using ultraviolet rays to the ignition in the gap 10 between the main discharge electrodes (hereinafter referred to as delay time _Td ) is the discharge circuit constant. (Peaking capacitor 7 → pre-ionization electrode 9 →
It is determined by the circuit between the main discharge electrode gap 10 and the peaking capacitor 7). The relationship between the delay time and the laser output energy is maximum within a certain range (200 to 400 ns in FIG. 4) as shown by the solid line in FIG. This is considered to be due to the balance between the time during which the initial electrons are formed by photoionization due to ultraviolet light and the electrons are uniformly distributed by diffusion, and the time during which the initial electrons are reduced due to the electron attachment of the halogen gas (gas laser medium).

In such a conventional pulse gas laser oscillation device, a residual current (after-current) flows between the main discharge electrodes 11 after the laser oscillation d as shown in FIG. Energy is so small that a glow discharge cannot be formed, so that the halogen gas between the main discharge electrodes 11 is not excited. Instead, a local arc discharge occurs, and as a result, the current density increases, and the main discharge electrode 11 is damaged by evaporation due to a rise in temperature or sputtering due to ion collision.

In the ultraviolet pre-ionization method, the pre-ionization electrode 9 is worn out by the operation for a long time (10 ⁹ to 10 ¹⁰ pulses), and the gap interval between the pre-ionization electrodes 9 becomes large or irregular. As a result, the uniformity and strength of the preionization are reduced. As a result, the average output of the pulse gas laser oscillation device itself decreases, and the output characteristics between the pulses also increase due to an increase in output fluctuation between pulses.

Further, the consumption of the preionization electrode 9 makes the excitation of the halogen gas occurring between the main discharge electrodes 11 unstable, thereby causing the main discharge electrode 11 to be consumed. In addition, the exhausted dust from the preliminary ionization electrode 9 not only pollutes the inside of the laser chamber but also deteriorates the halogen gas used for excitation. In order to prevent these, the main discharge electrode 11 and the preliminary ionization electrode 9 are periodically replaced. However, the cost and time required for the replacement are increased, and the operation rate of the apparatus is reduced.

When X-rays or corona discharge is used for preliminary ionization, a switching circuit dedicated to preliminary ionization may be provided. In this case, the delay time can be controlled by inserting a delay circuit. However, the pulse gas laser oscillator is not practically used at present because the circuit becomes complicated.

In the ultraviolet pre-ionization system, Japanese Patent Publication No. 7-8386 discloses a known example in which a pre-ionization circuit is provided so that the delay time can be adjusted by a circuit time constant. As a known example in which the delay time of an ionization circuit is adjustable by a delay circuit, Japanese Patent Publication No. 7-78
No. 57 exists.

[0009]

As described above, in the prior art, the preionization electrode 9 and the main discharge electrode 11 are worn out, and the life of each component constituting the pulsed gas laser oscillation device is shortened. Also, the halogen gas deteriorated quickly.

As described above, a method of providing a delay circuit to fix the delay time from the ignition of the preliminary ionization electrode 9 by ultraviolet rays to the ignition of the main discharge electrode 11 has been performed. The maximum range varies depending on the operating conditions (gas mixture ratio, total gas pressure, charging voltage, gas usage time, gap interval between pre-ionization electrodes, etc.). Fluctuations could not be avoided.

[0011]

According to a first aspect of the present invention, there is provided a container for enclosing an excitation gas, a main discharge electrode provided in the container so as to be opposed to the container, and a backup of the excitation gas between the main discharge electrodes. A pre-ionization electrode to be ionized, a charge / discharge circuit including a main capacitor for charging / discharging power supplied between the main discharge electrode and the pre-ionization electrode, a power supply for supplying power to the charge / discharge circuit, and a main capacitor A peaking capacitor electrically connected in parallel to the pair of main discharge electrodes for storing electric power from, and a pulse gas laser oscillation device including an optical resonator for amplifying light generated between the main discharge electrodes, A circuit connecting the main capacitor and the peaking capacitor is branched into a circuit through the preliminary ionization electrode and a circuit not through the preliminary ionization electrode, and at least one of the branched circuits is supersaturated. Akutoru a pulsed gas laser oscillator, wherein a is connected.

According to the second aspect of the present invention, the saturation current of the supersaturated reactor is changed so that the timing of the pulse current flowing through the preliminary ionization electrode and the timing of the other pulse currents are adjusted to the pulse current when the supersaturated reactor is not connected. Plus or minus 300n based on the timing of
The pulse gas laser oscillation device according to claim 1, wherein adjustment is performed within s.

According to a third aspect of the present invention, there is provided the pulse gas laser oscillation device according to the first aspect, wherein the current flowing through the preliminary ionization electrode is 30% or less of the total current. According to claim 4, the saturation time of the supersaturated reactor attached to both the circuit via the preliminary ionization electrode and the circuit without the preliminary ionization electrode is different from each other, wherein the pulse gas laser oscillation device according to claim 1, is there.

According to a fifth aspect of the present invention, there is provided the pulse gas laser oscillation device according to the first aspect, wherein an ionization system between the preliminary ionization electrode and the main discharge electrode is an automatic preliminary ionization system.

According to the sixth aspect, a container for enclosing the excitation gas, a main discharge electrode provided to face the container,
A pre-ionization electrode for pre-ionizing the excitation gas between the main discharge electrodes, a charge / discharge circuit including a main capacitor for charging / discharging electric power supplied between the main discharge electrode and the pre-ionization electrode; And a peaking capacitor electrically connected in parallel to the pair of main discharge electrodes for storing power from the main capacitor, and an optical resonance for amplifying light generated between the main discharge electrodes. And a circuit connecting the main capacitor and the peaking capacitor is divided into a circuit via the preliminary ionization electrode and a circuit without the preliminary ionization electrode, and a circuit not via the preliminary ionization electrode. Is a pulse gas laser oscillator characterized by having a lower impedance than the circuit through the preliminary ionization electrode.

According to the seventh aspect, a pulse gas laser oscillation device for emitting a laser beam, an optical system for shaping the laser beam emitted from the pulse gas laser oscillation device, and a laser beam shaped by the optical system are irradiated. A pulse gas laser oscillation device according to claim 1, wherein the pulse gas laser oscillation device is a pulse gas laser oscillation device according to claim 1. It is a laser annealing apparatus characterized by the following.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an equivalent circuit, in which the same reference numerals as in FIG. 21 denote parts equivalent to or corresponding to the conventional example.

A charging resistor 2, a main capacitor 3, and a floating inductance 4 are connected in series to a DC power supply 1. DC power supply 1, DC power supply 1 → Charging resistor 2 →
The main capacitor 3 is charged in a circuit of the main capacitor 3 → the charging reactor 6 → the DC power supply 1. When operated by inputting a trigger pulse to the thyratron 5 (high-voltage switching element), the charged charge is transferred to the main capacitor 3
→ stray inductance 4 → peaking capacitor 7a →
Circuit composed of Thyratron 5 and main capacitor 3 →
An automatic preionization system is formed in which the circuit is shifted to the peaking capacitors 7a and 7b in the circuit composed of the floating inductance 4, the preliminary ionization electrode 9, the peaking capacitor 7a, and the thyratron 5.

At this time, a preionization discharge is ignited between the preionization electrodes (pin electrodes) 9. The main discharge electrode 11 and the preliminary ionization electrode 9 are installed in a laser chamber (airtight container) in which a gas laser medium is sealed. FIG. 3A shows a voltage waveform between the main discharge electrodes 11, 11, and FIG. 3B shows a current waveform flowing through the pre-ionization electrodes 9, 9 and the main discharge electrodes 11, 11. In FIGS. 3A and 3B, when the supersaturated reactor (supersaturated inductance) 12a is not inserted into the circuit, the waveform shown by the solid line is obtained, and the time for the preionization current to start flowing (ignition of the preionization discharge) is shown. The delay time of the time when the main discharge current starts to flow (main discharge firing) is 400
ns.

At this time, as shown in FIG. 5, the energy fluctuation rate (σ) of each pulse of the laser output was 2.8%. By inserting the saturable reactor 12a, the current flowing through the preliminary ionization electrode 9 was delayed by the saturation time of the saturable reactor 12a (approximately 100 ns) to have a waveform shown by a dotted line. As a result, the delay time is reduced from 400 ns to 3
00 ns, and the energy fluctuation rate (σ) was reduced to 2.0%.

Although the output energy at this time does not change as shown by the solid line in FIG. 4, the output characteristic with respect to the delay time becomes as shown by the dotted line by changing the operating conditions such as the gas mixture ratio, and the output increases. In some cases, it is effective to both reduce the energy fluctuation rate.

It is needless to say that a similar effect can be obtained by using a semiconductor switch and a pulse compression circuit which have the same function and obtain a high frequency instead of the thyratron 5 used in the first embodiment. No.

For example, as shown in FIG. 6, the pulse width of the voltage waveform between the main discharge electrodes 11 may be short due to the effect of pulse compression. In this case, when the supersaturated reactor 12b is not inserted into the circuit, the waveform becomes a solid line. In this case, the delay time of the time at which the main discharge current starts to flow (ignition of the main discharge) with respect to the time at which the preliminary ionization current starts to flow (ignition of the pre-ionization discharge) was 200 ns.

At this time, as shown in FIG. 5, the energy fluctuation rate (σ) of each pulse of the laser output is 3.0.
%Met. By inserting the saturable reactor 12b, the current flowing through the peaking capacitor 7b is delayed by the saturation time of the saturable reactor 12b (about 100 n).
s), the voltage waveform was as shown by the dotted line in FIG. As a result, the delay time was changed from 200 ns to 300 ns, and the energy fluctuation rate (σ) was reduced to 2.0%. The output energy at this time does not change as shown by the solid line in FIG.

That is, the peaking capacitors 7a, 7b
The supersaturated reactor 1 is connected to the conductor connecting the main discharge electrode 11 and
By attaching the cores 2a and 12b, the delay time can be adjusted. Since the cores of the supersaturated reactors 12a and 12b are generally half-split types, they can be easily attached and detached. By adjusting the mounting position and the number of stages of the cores of the supersaturated reactors 12a and 12b, the delay time can be adjusted in both the plus direction and the minus direction. Of course, the cores of the supersaturated reactors 12a and 12b may be attached to both the peaking capacitors 7a and 7b, and the cores may be adjusted by the difference in the saturation time.

The current flowing through the preionization electrode 9 can be adjusted by changing the capacitance ratio between the peaking capacitors 7a and 7b. By reducing the capacitance of the peaking capacitor 7a, the main capacitor 3 → the floating inductance 4 → Supersaturated reactor 7b → Peaking capacitor 7
Most of the current flows through the circuit composed of b → thyratron 5. That is, a bypass circuit for the preliminary ionization electrode 9 is provided.

As a result, the consumption of the preionization electrode 9 can be prevented, and the life of the components and the gas medium of the preionization electrode 9 can be extended. In this embodiment, good results were obtained when the current flowing through the preliminary ionization electrode 9 was 30% or less of the total capacity of the peaking capacitor 7a.

FIG. 7 shows an equivalent circuit of a modified example according to the first embodiment of the present invention. The operation is the same, but the position of the preionization electrode 9 is different (the first embodiment is connected in parallel to the main discharge electrode 11, whereas in this modification, it is connected in series to the main discharge electrode 11). 1), and the operations of the components having the same reference numerals are the same as those in FIG. For these circuit configurations,
It goes without saying that various modifications are possible in accordance with the gist of the present invention.

Next, FIG. 8 shows a schematic configuration diagram of a second embodiment of the present invention. A gas laser medium is sealed in the laser chamber 13, and the DC power supply 1 supplies a gap 10 between the main discharge electrodes 11, that is, a gap 10 between the main discharge electrodes.
, A main discharge occurs. Light oscillated by the main discharge is amplified by a laser resonator (not shown) and output as laser light.

In the second embodiment, before the main discharge is ignited in the gap 10 between the main discharge electrodes, the discharge space between the main discharge electrodes 11 (the gap 10 between the main discharge electrodes) is set.
And a plurality of preionization means including a ballast coil 14 and a preionization electrode (pin electrode) 9 for preionization. The ballast coil 14 is provided to allow a current (current flowing from the main capacitor 3 to the peaking capacitor 7) to flow uniformly between the plurality of preliminary ionization electrodes 9. A supersaturated reactor 12 is connected in parallel with the above-mentioned preionization means, and constitutes a bypass circuit for the preionization means.

FIG. 9 shows an equivalent circuit according to the second embodiment. To the DC power supply 1, a charging resistor 2, a main capacitor 3, and a stray inductance 4 are connected in series. The main capacitor 3 is charged by the DC power supply 1 in a circuit of DC power supply 1 → main capacitor 3 → saturated reactor 12 → reactor 6 for charging → DC power supply 1. Here, the charging reactor 6 also has the function of releasing the saturation of the supersaturated reactor 12. At this time, since the voltage between the preionization electrodes 9 does not increase, the preionization discharge does not fire.

When the thyratron 5 is operated by inputting a trigger pulse, the main capacitor 3
Is charged from the main capacitor 3 to the thyratron 5
The peaking capacitor 7 is transferred to the peaking capacitor 7 by the circuit composed of the peaking capacitor 7, the preliminary ionization electrode 9, the ballast coil 14, and the main capacitor 3. At this time, a preionization discharge is ignited between the preionization electrodes 9. The supersaturated reactor 12 is designed such that when the product of the applied voltage and the voltage time, that is, the flowing current reaches a predetermined value (immediately after the ignition of the preionization discharge), the saturation occurs, the inductance decreases, and the superconducting reactor 12 is brought into a conductive state. .

Therefore, since the impedance in the conducting state is smaller than that of the circuit composed of the ballast coil 14 and the preionization electrode 9, the electric charge charged in the main capacitor 3 immediately after the preionization discharge is Since the circuit shifts to the peaking capacitor 7 in a circuit composed of the capacitor 3, the thyratron 5, the peaking capacitor 7, the supersaturation reactor 12, and the main capacitor 3, it is a bypass circuit for the preliminary ionization means as described above. FIG. 10 shows a current flowing through the preionization electrode 9 and a current flowing through the saturable reactor 12 (bypass circuit).

Although the circuit using the supersaturated reactor 12 has been described so far, the same effect can be obtained by using a thyratron or a gap switch. FIG. 11 shows an equivalent circuit according to the third embodiment of the present invention, which is constituted by the bypass circuit using the thyratron 15. The other configuration is the same as that of the second embodiment shown in FIG. 9 except that the thyratron 15 is used to constitute the bypass circuit.

FIG. 10 shows the current flowing through the preliminary ionization electrode 9 and the current flowing through the bypass circuit.
This will be described in conjunction with 1. A trigger pulse is input at time t ₁ in FIG. 10, and the thyratron 5 in FIG. 11 starts operating. After the time required for preliminary ionization is delayed by the delay circuit 16, the thyratron 15 at time t ₂ in FIG.
Starts working. With such a configuration, an effect similar to that of the second embodiment is obtained.

FIG. 12 shows a fourth embodiment in which a bypass reactor 17 (in this case, 1 μH) having an inductance value of 1 μH or less is connected instead of the supersaturated reactor 12 in the second embodiment of the present invention. An equivalent circuit for is shown. Here, even if the thyratron 5 starts to operate after the main capacitor 3 is charged, the value of the bypass reactor 17 is reduced as much as possible for the preliminary ionization discharge to be fired, so that the current flows through the bypass circuit. It was done. Here, the inductance value of the charging reactor 6 is 50 μH, the inductance value of the ballast coil 14 is 10 μH, the capacitance of the main capacitor 3 is 20 nF, and the capacitance of the peaking capacitor is 20 nH.
F is set.

The pre-ionization discharge is ignited between the pre-ionization electrodes 9 by the back electromotive force of the bypass reactor 17. This embodiment has an advantage that the current flowing through the bypass circuit is smaller than that of the above embodiment, but the circuit can be easily configured.

FIG. 13 shows an equivalent circuit according to the fifth embodiment of the present invention. In the fifth embodiment, the main capacitor 3a is connected to a main capacitor 3a which contributes to preliminary ionization discharge.
(A series connection to the ballast coil 14) and a main capacitor 3b (a series connection to the bypass reactor 17) contributing to the bypass circuit. According to the fourth embodiment, although the circuit is more complicated than the fourth embodiment, the inductance value of the bypass circuit can be reduced (several tens μH or less), and the current flowing through the bypass circuit can be reduced. Can be increased.

FIG. 14 shows an equivalent circuit according to the sixth embodiment of the present invention. The main capacitor 3 is charged by the DC power supply 1 in a circuit of DC power supply 1 → charging resistor 2 → main capacitor 3 → saturated reactor 12c → attenuation resistor 18 → variable reactor 19 → DC power supply 1. The conduction state of the supersaturated reactor 12c is released by the current flowing in the circuit for charging the main capacitor 3.

Next, when the trigger pulse is input to the thyratron 5 and the thyratron 5 is operated, the electric charge charged in the main capacitor 3 is changed from the main capacitor 3 → the thyratron 5 → the peaking capacitor 7 → the preliminary ionizing electrode 9 → the circuit of the main capacitor 3. Then, the process shifts to the peaking capacitor 7 and the preionization discharge is ignited between the preionization electrodes 9.

When the product of the applied voltage and the voltage application time, that is, the flowing current reaches a predetermined value (immediately after the ignition of the preionization discharge), the supersaturated reactor 12c is saturated, the inductance value decreases, and the superconducting reactor 12c becomes conductive. It has become. The attenuation resistor 18 and the variable reactor 19 are designed so that the supersaturated reactor 12c is saturated immediately after the ignition of the preionization discharge.

In this conducting state, the impedance charged is smaller than that of the ballast coil 14 and the preionization electrode 9. 3 → supersaturated reactor 12 c → attenuation resistor 18 → variable reactor 19 → transition to attenuation resistor 18 in a circuit composed of main capacitor 3. Since a large part of the electric energy is consumed by the attenuating resistor 18, it forms a bypass circuit for the preliminary ionization means as described above.

In FIG. 15, (a) shows a current I flowing between the main discharge electrodes 11 of the circuit described in the section of [Prior Art], and (b) shows a current I flowing through the main discharge electrode 9.
₁ and (c) shows the current I flowing through the bypass circuit.
₂ is shown, and (d) shows the laser pulse waveform W. As for the supersaturated reactor 12c, the conduction (saturation) timing is indicated by "continuity of supersaturated inductance" (ON state of the supersaturated reactor), and the laser output does not decrease immediately after laser oscillation.

However, the conduction timing is shown in FIG.
Is determined by the area (the product of the applied voltage and the voltage application time) of the hatched portion of the voltage waveform V of the gap 10 between the main discharge electrodes indicated by the symbol (b). As the value of V changes, the conduction becomes as shown in FIG. Also changes. Therefore, in this embodiment, the supersaturated reactor 12
A variable reactor 19 is inserted in series with the saturable reactor 12c in order to compensate for the conduction timing of c. For example, V changes when constant output control is performed with the charging voltage, or when gas is deteriorated or gas mixing conditions change.

In the case where the charging voltage is low, FIG.
As shown in (a), the conduction timing is advanced, and a current required for laser oscillation flows through the bypass circuit as shown in FIG. As a result, current I ₂ is increased relative to the current I ₁ is decreased, the laser output is reduced.

On the other hand, as shown in FIG. 4C, the later the conduction timing is, the smaller the current I ₂ is,
The effect of reducing the residual current (after-current) in the gap 10 between the main discharge electrodes, which has been a problem in the section of [Prior Art], is reduced.

Therefore, by adjusting the value of the variable reactor 19, the voltage waveform applied to the saturable reactor 12c is changed so that the conduction timing of the saturable reactor 12c is always maintained immediately after laser oscillation (optimum value). . For example, when the output of the laser oscillator is controlled to be constant and the gas laser medium is deteriorated and the charging voltage is gradually increased, the value of the variable reactor 19 is gradually reduced by the controller 20 in FIG. Can respond. On the other hand, if the charging voltage sharply decreases during the injection of the gas laser medium, the variable reactor 19
Can be dealt with by rapidly increasing the value of

FIG. 18 shows an equivalent circuit of a modification of the sixth embodiment. This modification takes the protection of the thyratron 5 into consideration. In order to reduce the power consumption of the thyratron 5, a supersaturated reactor 12d connected to the main capacitor 3 in series and using the magnetic assist method is provided. In addition, the thyratron 5 has a diode 21 in order to prevent a current from flowing in the opposite direction.
Furthermore, the charging resistor 2 consumes most of the power, and forms a bypass circuit for the above-mentioned preliminary ionization means.

In each of the above embodiments, FIG.
A dielectric 22 is attached to the preionization electrode 9 as shown in FIG.
It is also effective to reduce the discharge starting voltage by utilizing the creeping discharge of the dielectric 22. The discharge starting voltage can be reduced by keeping the gap interval between the preliminary ionization electrodes 9 as small as about 1 to 2 mm. However, if the interval is too small, the capability of the preliminary ionization is reduced. It is desirable to use a simple dielectric 22.

Next, a seventh embodiment of the present invention will be described. FIG. 20 shows a laser annealing apparatus using the pulsed gas laser oscillator according to the first to sixth embodiments of the present invention. In recent years, in the field of semiconductor devices and liquid crystal display devices, plasma CVs using silane gas (SiH ₄ )
Amorphous silicon (amorphous silicon: a-Si) film formed on a substrate by a D (Chemical Vapor Deposition) method (a process of about 300 ° C.) is irradiated with laser light or the like, and is made of polycrystalline silicon (polysilicon). : P-Si) film to form a polycrystalline semiconductor film with high electron mobility and to activate impurities (donor / acceptor) that cause the semiconductor film to operate as a transistor. Excimer Laser Anneal (ELA) technology has been developed for this purpose.

The laser annealing apparatus shown in FIG. 20, which is used when manufacturing a liquid crystal display device using the above-mentioned polycrystalline silicon film, will be described in detail. This laser annealing apparatus irradiates a substrate 101 (workpiece) on which an a-Si: H film (a-Si film containing hydrogen) is formed with a XeCl laser beam.

The laser light emitted from the pulsed gas laser oscillation device 102 shown in the first to sixth embodiments of the present invention is condensed by a condensing lens 104 such as a cylindrical lens via a collimator 103. The light enters the inside from the entrance end face of the kaleidoscope 105 as an optical system including a homogenizer. This Callide Scope 10
Reference numeral 5 has a cylindrical configuration in which four polished aluminum plates having high reflectivity are combined. It has a rectangular parallelepiped shape and has a rectangular hollow inside. At the emission end face of the kaleidoscope 105, light whose energy intensity distribution is flattened on the irradiation surface of the laser light due to multiple reflection of light at the hollow part of the kaleidoscope 105 is emitted in a line shape.

The laser light emitted from the exit end face of the kaleidoscope 105 is reflected downward by the mirror 106 and is formed by the imaging lens 107 through the window 108 to form an a-Si: H film in the processing chamber 109. Filmed substrate 1
01. That is, at this time, the image plane of the laser beam is on the substrate 101. The substrate 101 is an XY table 110
On which the laser light and the substrate 101 are placed.
Are scanned relative to. The processing chamber 10
9 is cut off from the outside world by the gate valve G,
The inside thereof is evacuated by a vacuum pump via a valve, or is filled with an inert gas represented by N ₂ supplied from a N ₂ cylinder via a valve, depending on these setting conditions. It is in a state where an optimal annealing process can be performed.

Here, by using the pulse gas laser oscillators according to the first to sixth embodiments of the present invention, it is possible to obtain a highly stable pulse gas laser oscillator having a small variation in laser energy for each pulse. It has become possible to perform good annealing treatment. Also,
The periodic replacement cycle of the main discharge electrode and the preionization electrode is extended, the cost and time required for replacement are reduced, the operation rate is improved, and the life of the laser annealing apparatus can be extended.

[0055]

As described above, according to the pulse gas laser oscillation apparatus of the present invention, according to the first to seventh aspects of the present invention, it is difficult to adjust the delay time of the main discharge with respect to the preionization discharge. In the UV-excited automatic preionization method, the circuit connecting the main capacitor and the peaking capacitor was branched into one through the preionization electrode and one without, and a saturable reactor was connected to at least one of the circuits. Thus, a highly stable laser oscillation device with small fluctuations in laser energy for each pulse was made possible, and the input to the preliminary ionization electrode could be reduced.

Further, when the circuit is branched into a circuit through the preliminary ionization electrode and a circuit without the preliminary ionization electrode, the impedance is lower than that through the impedance without the preliminary ionization electrode, so that the life of the device can be extended. Became. Further, by using this pulse gas laser oscillation device, the operating rate of the laser annealing device is improved, and the life of the laser annealing device can be extended.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a connection structure of a main part of the pulse gas laser oscillation device of FIG.

3 is a graph showing a voltage waveform and a current waveform between main discharge electrodes according to the pulsed gas laser oscillation device of FIG.

FIG. 4 is a graph of laser output energy and delay time according to the pulsed gas laser oscillation device of FIG. 1;

FIG. 5 is a graph of a laser output energy variation rate and a delay time according to the pulse gas laser oscillation device of FIG. 1;

FIG. 6 is a graph showing a voltage waveform between main discharge electrodes according to the pulse gas laser oscillation device of FIG. 1;

FIG. 7 is an equivalent circuit diagram of a pulse gas laser oscillation device according to another example of the first embodiment of the present invention.

FIG. 8 is a cross-sectional configuration diagram of a pulse gas laser oscillation device according to a second embodiment of the present invention.

FIG. 9 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a second embodiment of the present invention.

10 is a graph showing current waveforms between pre-ionization electrodes and in a bypass circuit according to the pulsed gas laser oscillation device of FIG. 9;

FIG. 11 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a third embodiment of the present invention.

FIG. 12 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a fourth embodiment of the present invention.

FIG. 13 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a fifth embodiment of the present invention.

FIG. 14 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a sixth embodiment of the present invention.

FIG. 15 shows a conventional pulse gas laser oscillation device and FIG.
4 is a graph showing a current waveform and a laser pulse waveform between main discharge electrodes and in a bypass circuit according to the pulse gas laser oscillation device of FIG.

16 is a graph showing a voltage waveform and a current waveform between main discharge electrodes and a current waveform of a bypass circuit in the pulse gas laser oscillation device of FIG.

FIG. 17 is a graph showing a case where the conduction timing of the supersaturated reactor in the graph of FIG. 16 is changed.

FIG. 18 is an equivalent circuit diagram of a pulse gas laser oscillation device according to another example of the sixth embodiment of the present invention.

FIG. 19 is an enlarged configuration diagram of a preliminary ionization electrode of the pulse gas laser oscillation device according to the present invention.

FIG. 20 is a schematic configuration diagram of a laser annealing apparatus according to a seventh embodiment of the present invention.

FIG. 21 is an equivalent circuit diagram of a pulse gas laser oscillation device according to a conventional example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DC power supply, 2 ... Charge resistance, 3.3a / 3b ... Main capacitor 4 ... Floating inductance, 5-15 ... Thyratron, 6
... Charging reactors 7,7a, 7b ... Peaking capacitors, 9 ... Pre-ionization electrodes 10 ... Gap between main discharge electrodes, 11 ... Main discharge electrodes 12a, 12b, 12c, 12d ... Supersaturated reactors,
DESCRIPTION OF SYMBOLS 13 ... Laser chamber 14 ... Ballast coil, 16 ... Delay circuit, 17 ... Bypass reactor 18 ... Attenuation resistor, 19 ... Variable reactor, 20 ... Controller 21 ... Diode, 22 ... Dielectric, 101 ... Substrate 102 ... Pulse gas laser oscillation Apparatus, 103 Collimator, 104 Condensing lens 105 Callide scope, 106 Mirror, 107
Imaging lens 108 Window, 109 Processing chamber 110 XY table

Claims (7)

[Claims] 1. A container for enclosing an excitation gas, a main discharge electrode provided in the container so as to face the same, a preionization electrode for preionizing the excitation gas between the main discharge electrodes, and a main discharge electrode. A charge / discharge circuit including a main capacitor for charging / discharging power supplied between the preliminary ionization electrodes; a power supply for supplying power to the charge / discharge circuit; and the pair of main discharges for storing power from the main capacitor. A pulse gas laser oscillation device comprising: a peaking capacitor electrically connected in parallel to electrodes; and an optical resonator that amplifies light generated between the main discharge electrodes. A circuit connecting the main capacitor and the peaking capacitor. Are divided into those via the preliminary ionization electrode and those not through the preliminary ionization electrode, and the supersaturated reactor is connected to at least one of the branched circuits. Pulsed gas laser oscillator according to symptoms. 2. The timing of the pulse current flowing through the preliminary ionization electrode and the timing of the other pulse current by changing the saturation time of the supersaturated reactor, and the timing of the pulse current flowing when the supersaturated reactor is not connected. 2. The pulse gas laser oscillation device according to claim 1, wherein the pulse gas laser oscillation device is adjusted within ± 300 ns within ± 300 ns. 3. The pulse gas laser oscillation device according to claim 1, wherein a current flowing through the preliminary ionization electrode is 30% or less of a total current. 4. The pulse gas laser oscillation device according to claim 1, wherein the saturation times of the supersaturated reactors attached to both the circuit via the preliminary ionization electrode and the circuit without the preliminary ionization electrode are different. 5. The pulse gas laser oscillation device according to claim 1, wherein an ionization method between the preliminary ionization electrode and the main discharge electrode is an automatic preionization method. 6. A container for enclosing an excitation gas, a main discharge electrode provided in the container so as to face the same, a preionization electrode for preionizing the excitation gas between the main discharge electrodes, and a main discharge electrode. A charge / discharge circuit including a main capacitor for charging / discharging power supplied between the preliminary ionization electrodes; a power supply for supplying power to the charge / discharge circuit; and the pair of main discharges for storing power from the main capacitor. A pulse gas laser oscillation device comprising: a peaking capacitor electrically connected in parallel to electrodes; and an optical resonator that amplifies light generated between the main discharge electrodes. A circuit connecting the main capacitor and the peaking capacitor. Are divided into those through the preliminary ionization electrode and those not through the preliminary ionization electrode, and the circuit that does not pass through the preliminary ionization electrode is the circuit that passes through the preliminary ionization electrode. Remote pulsed gas laser oscillator, characterized by having a low impedance. 7. A pulse gas laser oscillation device for emitting a laser beam, an optical system for shaping a laser beam emitted from the pulse gas laser oscillation device, and an object to be irradiated with the laser beam shaped by the optical system. 7. A laser annealing apparatus comprising: a chamber in which a pulse gas laser oscillating device is provided. 7. The laser annealing device according to claim 1, wherein the pulse gas laser oscillating device is the pulse gas laser oscillating device according to any one of claims 1 to 6. apparatus.