Injection locking type or MOPA type of laser device
An injection locking type or MOPA type of laser device capable of always providing stable output energy and wavelength is provided. For this purpose, the laser device includes an oscillator for exciting laser gas by oscillator discharge and oscillating seed laser light with band-narrowed wavelength, an amplifier for amplifying the seed laser light by amplification discharge to emit amplified laser light, a delay circuit for setting at least one of a delay time from light emission of the seed laser light to light emission of the amplified laser light, and a delay time from start of the oscillator discharge to start of the aforementioned amplification discharge, and a delay time compensation circuit for performing compensation of the delay circuit so that the delay time becomes an optimal delay time.
1. An injection locking type or MOPA type of laser device, comprising:
an oscillator having an amplification discharge circuit for exciting a laser gas by oscillator discharge said oscillator emitting oscillated seed laser light having a band-narrowed wavelength;
an amplifier having a discharge circuit for amplifying said oscillated seed laser light to emit amplified laser light;
a delay circuit for selling at least one of a plurality of delay times between parameters associated with a synchronization process of said oscillator and said amplifier;
jitter compensation circuits provided at each of said oscillator and said amplifier, each jitter compensation circuit compensating the jitter of a total elapsed time from a reference trigger signal being a reference to a start of said oscillator discharge and amplification discharge based on a charge voltage applied to each respective discharge circuit of said oscillator and said amplifier; and
drift compensation circuits for compensating said jitter compensation circuits of said oscillator and said amplifier based on changes in characteristics of each respective discharge circuit.
2. The injection locking type or MOPA type of laser device according to claim 1 ,
wherein the compensation of said jitter is performed based on an inverse of said charge voltage.
3. The injection locking type or MOPA type of laser device according to claim 1 , wherein compensation of the jitter is performed for each pulse oscillation.
4. The injection locking type or MOPA type of laser device according to claim 2 , wherein compensation of the jitter is performed for each pulse oscillation.
5. An aligner for integrated circuit manufacturing with an injection locking type or MOPA type of laser device as a light source, the laser device comprising:
an amplifier that amplifies seed laser light to emit amplified laser light;
a laser monitor that receives the emitted amplified laser light and outputs a plurality of laser parameters of the emitted amplified laser light;
an aligner that receives the amplified laser light and outputs a trigger signal; and
a laser controller that receives the trigger signal from the aligner and receives the laser parameters from the laser monitor, the laser controller suspending exposure processing based on a command from the aligner during exposure, performing adjustment oscillation when the exposure is suspended so that the laser parameters are within a predetermined range when the exposure is resumed, and performing compensation for each of a delay time, jitter, and drift during adjustment oscillation, so that resumption of exposure is enabled, wherein when exposure is suspended the amplified laser light is prevented from emitting to the aligner.
6. An exposure method by an injection locking type or MOPA type of laser device, comprising the steps of:
monitoring a plurality of laser parameters of emitted laser light;
suspending exposure processing based on a command from an aligner during exposure;
performing adjustment oscillation when the exposure is suspended, and performing compensation for each of a delay time, jitter, and drift during the adjustment oscillation, wherein when the exposure is suspended amplified laser light is prevented from emitting to the aligner; and
enabling a resumption of exposure the laser parameters being within a predetermined range.
7. An aligner for integrated circuit manufacturing with an injection locking type or MOPA type of laser device as a light source, the laser device comprising:
an amplifier that amplifies seed laser light to emit amplified laser light;
an aligner that receives the amplified laser light and outputs a trigger signal; and
a laser controller that receives the trigger signal from the aligner, the laser controller suspending exposure processing based on a command from the aligner during exposure, performing adjustment oscillation when the exposure is suspended so that the laser parameters are within a predetermined range when the exposure is resumed, and performing compensation for each of a delay time, jitter, and drift during adjustment oscillation, so that resumption of exposure is enabled, wherein when exposure is suspended the amplified laser light is prevented from emitting to the aligner.
8. An injection locking type or MOPA type of laser device comprising:
an amplifier that amplifies seed laser light to emit amplified laser light; and
a laser controller that receives the trigger signal from the aligner, the laser controller suspending exposure processing based on a command from the aligner during exposure, performing adjustment oscillation when the exposure is suspended so that the laser parameters are within a predetermined range when the exposure is resumed, and performing compensation for each of a delay time, jitter, and drift during adjustment oscillation so that resumption of exposure is enabled, wherein when exposure is suspended the amplified laser light is prevented from emitting to the aligner.