Seed light generation device, light source device, adjustment method thereof, light irradiation device, exposure device, and device manufacturing method

• US 20110211184A1
• Filed: 12/09/2010
• Published: 09/01/2011
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: INABA, Naoto, TOKUHISA, Akira
• Granted Patent: US 8,792,083 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G02F 1/353 Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
• CPC Class Codes: G03F 7/70025 by lasers
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 5/0085 for modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 5/06216 Pulse modulation or generation
• CPC Class Codes: H01S 5/50 Amplifier structures not provided for in groups H01S5/02 - H01S5/30

Abstract

A light source device including a seed light generation device, a light amplification unit which optically amplifies seed light generated by the seed light generation device, and a wavelength conversion unit which converts the wavelength of the light optically amplified by the light amplification unit. The seed light generation device includes a pulsed light generation unit which generates pulsed light having a single wavelength, a pulse modulation unit which selectively passes and extracts a part of the pulsed light, and a timing adjustment unit which relatively adjusts the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

Claims

1. A light source device, comprising:

a seed light generation device which generates seed light to be optically amplified;

a light amplification unit which optically amplifies the seed light generated by the seed light generation device; and

a wavelength conversion unit which converts a wavelength of the light optically amplified by the light amplification unit, and outputs ultraviolet pulsed light,

the seed light generation device including;

a pulse generation unit which generates pulsed light having a single wavelength;

a pulse modulation unit which selectively passes and extracts a part of the pulsed light; and

a timing adjustment unit which adjusts a spectral width of the ultraviolet pulsed light to be output from the wavelength conversion unit by relatively adjusting the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

2. The light source device according to claim 1, wherein

a range of the relative adjustment of the extracting timing during the generation period by the timing adjustment unit is a range that includes a timing when the part of the pulsed light becomes a part of a portion, of the pulsed light, where a light intensity decreases.

3. The light source device according to claim 1, wherein the pulse generation unit is a laser diode which generates the pulsed light in response to a pulsed electric signal.

4. A method for adjusting the light source device according to claim 1, comprising:

operating the timing adjustment unit so that the spectral width of the ultraviolet pulsed light output from the wavelength conversion unit becomes a desired spectral width, while observing the spectral width of the ultraviolet pulsed light.

5. A light irradiation device for irradiating light onto an object, comprising:

the light source device according to claim 1; and

an irradiation optical system which irradiates ultraviolet pulsed light from the light source device onto the object.

6. An exposure device for transferring a pattern of a mask onto a photosensitive object, comprising:

the light source device according to claim 1;

an irradiation optical system which irradiates ultraviolet pulsed light from the light source device onto the mask; and

a projection optical system which projects the ultraviolet pulsed light from the mask onto the photosensitive object.

7. A device manufacturing method including a lithography step,

the lithography step comprising using the exposure device according to claim 6 to transfer a pattern of the mask onto the photosensitive object.

8. The light source device according to claim 2, wherein the pulse generation unit is a laser diode which generates the pulsed light in response to a pulsed electric signal.

9. An exposure device for transferring a pattern of a mask onto a photosensitive object, comprising:

the light source device according to claim 2,

an irradiation optical system which irradiates ultraviolet pulsed light from the light source device onto the mask; and

a projection optical system which projects the ultraviolet pulsed light from the mask onto the photosensitive object.

10. An exposure device for transferring a pattern of a mask onto a photosensitive object, comprising:

the light source device according to claim 3,

an irradiation optical system which irradiates ultraviolet pulsed light from the light source device onto the mask; and

a projection optical system which projects the ultraviolet pulsed light from the mask onto the photosensitive object.

11. An exposure device for transferring a pattern of a mask onto a photosensitive object, comprising:

the light source device according to claim 8,

an irradiation optical system which irradiates ultraviolet pulsed light from the light source device onto the mask; and

a projection optical system which projects the ultraviolet pulsed light from the mask onto the photosensitive object.