Laser apparatus and method for manufacturing electronic devices

A method for manufacturing electronic devices, the method comprising:

• generating laser light by a laser apparatus including
• an oscillator configured to output pulse laser light,
• an optical element disposed in an optical path of the pulse laser light,
• a rotary stage configured to support the optical element,
• a grating on which the pulse laser light is incident via the optical element and which is disposed so as to cause diffracted light having a wavelength according to an angle of incidence of the pulse laser light to return to the oscillator,
• a first driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the rotary stage to rotate the optical element,
• a second driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the rotary stage by a smaller amount than an amount driven by the first driving mechanism to rotate the optical element,
• a wavelength monitor configured to measure a center wavelength of the pulse laser light, and
• a processor configured to cyclically change a target wavelength of the pulse laser light and control the center wavelength to coincide with the target wavelength by outputting a drive instruction to the second driving mechanism to change the angle of incidence based on the target wavelength and a value measured by the wavelength monitor,
• the processor configured to calculate a moving average of drive instruction values by which the second driving mechanism is driven over a segment that is an integer multiple of a wavelength instruction cycle in which the target wavelength is cyclically changed, the processor further configured, when the calculated moving average exceeds a threshold, to cause the second driving mechanism to return to an initial position, and drive the first driving mechanism to cancel a change in the angle of incidence caused by the return of the second driving mechanism to the initial position;
• outputting the laser light to an exposure apparatus;
• and
• exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture electronic devices.

A laser apparatus comprising:

• an oscillator configured to output pulse laser light;
• a first optical element disposed in an optical path of the pulse laser light;
• a first rotary stage configured to support the first optical element;
• a second optical element disposed in the optical path of the pulse laser light;
• a second rotary stage configured to support the second optical element;
• a grating on which the pulse laser light is incident via the first and second optical elements and which is disposed so as to cause diffracted light having a wavelength according to an angle of incidence of the pulse laser light to return to the oscillator;
• a first driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the first rotary stage to rotate the first optical element;
• a second driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the second rotary stage by a smaller amount than an amount driven by the first driving mechanism to rotate the second optical element;
• a wavelength monitor configured to measure a center wavelength of the pulse laser light;
• and
• a processor configured to cyclically change a target wavelength of the pulse laser light and control the center wavelength to coincide with the target wavelength by outputting a drive instruction to the second driving mechanism to change the angle of incidence based on the target wavelength and a value measured by the wavelength monitor,
• the processor configured to calculate a moving average of drive instruction values by which the second driving mechanism is driven over a segment that is an integer multiple of a wavelength instruction cycle in which the target wavelength is cyclically changed, the processor further configured, when the calculated moving average exceeds a threshold, to cause the second driving mechanism to return to an initial position, and drive the first driving mechanism to cancel a change in the angle of incidence caused by the return of the second driving mechanism to the initial position.

A method for manufacturing electronic devices, the method comprising:

• generating laser light by a laser apparatus including
• an oscillator configured to output pulse laser light,
• a first optical element disposed in an optical path of the pulse laser light,
• a first rotary stage configured to support the first optical element,
• a second optical element disposed in the optical path of the pulse laser light,
• a second rotary stage configured to support the second optical element,
• a grating on which the pulse laser light is incident via the first and second optical elements and which is disposed so as to cause diffracted light having a wavelength according to an angle of incidence of the pulse laser light to return to the oscillator,
• a first driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the first rotary stage to rotate the first optical element,
• a second driving mechanism configured to change the angle of incidence of the pulse laser light to be incident on the grating by driving the second rotary stage by a smaller amount than an amount driven by the first driving mechanism to rotate the second optical element,
• a wavelength monitor configured to measure a center wavelength of the pulse laser light, and
• a processor configured to cyclically change a target wavelength of the pulse laser light and control the center wavelength to coincide with the target wavelength by outputting a drive instruction to the second driving mechanism to change the angle of incidence based on the target wavelength and a value measured by the wavelength monitor,
• the processor configured to calculate a moving average of drive instruction values by which the second driving mechanism is driven over a segment that is an integer multiple of a wavelength instruction cycle in which the target wavelength is cyclically changed, the processor further configured, when the calculated moving average exceeds a threshold, to cause the second driving mechanism to return to an initial position, and drive the first driving mechanism to cancel a change in the angle of incidence caused by the return of the second driving mechanism to the initial position;
• outputting the laser light to an exposure apparatus;
• and
• exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture electronic devices.