ILLUMINATING APPARATUS, PATTERN INSPECTION APPARATUS, AND METHOD OF FORMING ILLUMINATING LIGHT

• US 20120189032A1
• Filed: 01/17/2012
• Published: 07/26/2012
• Est. Priority Date: 01/20/2011
• Status: Active Grant

• Current Assignee: NuFlare Technology, Inc. (Toshiba Corporation)
• Original Assignee: NuFlare Technology, Inc. (Toshiba Corporation)
• Inventors: OGAWA, Riki
• Granted Patent: US 8,755,040 B2
• Time in Patent Office: Days
• US Class Current: 372/101
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: B23K 26/0676 into dependently operating sub-beams, e.g. an array of spots with fixed spatial relationship or for performing simultaneously identical operations
• CPC Class Codes: G01N 2021/95676 Masks, reticles, shadow masks
• CPC Class Codes: G01N 21/9505 Wafer internal defects, e.g. microcracks
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/95607 using a comparative method
• CPC Class Codes: G03F 1/84 Inspecting

Abstract

An illuminating apparatus includes a rotating phase plate having a height equal to or less than a wavelength of light from a light source and including a plurality of randomly arranged step regions so as to change a phase of light from the light source by allowing the light beam to pass therethrough; and a fly'"'"'s eye lens including an array of a plurality of lenses configured to pass the light beam passed through the rotating phase plate, wherein a portion in which a product of a maximum size of the plurality of step regions and an optical magnification from the rotating phase plate to a plane of incidence of the fly'"'"'s eye lens is equal to or less than an arrangement pitch of the plurality of lenses and a portion in which the product is larger than the arrangement pitch of the plurality of lenses are mixed.

Claims

1. An illuminating apparatus, comprising:

a light source configured to generate coherent light;

a rotating phase plate in which a plurality of step regions is arranged randomly and has a height equal to or less than a wavelength of the light, and configured to change a phase of a light beam from the light source by allowing the light beam to pass therethrough; and

a fly'"'"'s eye lens in which a plurality of lenses is arranged like an array and configured to allow the light beam having passed through the rotating phase plate to pass,

wherein a portion in which a product of a maximum size of the plurality of step regions and an optical magnification from the rotating phase plate to a plane of incidence of the fly'"'"'s eye lens is equal to or less than an arrangement pitch of the plurality of lenses and a portion in which the product is larger than the arrangement pitch of the plurality of lenses are mixed.

2. The apparatus according to claim 1, wherein a shape of the plurality of step regions on a surface perpendicular to a direction of an optical axis is formed as a quadrangle.

3. The apparatus according to claim 1, wherein a shape of the plurality of step regions on a surface perpendicular to a direction of an optical axis is formed as a triangle.

4. The apparatus according to claim 1, wherein a shape of the plurality of step regions on a surface perpendicular to a direction of an optical axis is formed as a polygon.

5. The apparatus according to claim 1, further comprising:

a lens configured to be arranged between the rotating phase plate and the fly'"'"'s eye lens and to adjust the optical magnification.

6. An illuminating apparatus, comprising:

a light source configured to generate coherent light;

a rotating phase plate in which a plurality of step regions is arranged randomly and has a height equal to or less than a wavelength of the light, and configured to change a phase of a light beam from the light source by allowing the light beam to pass therethrough; and

a fly'"'"'s eye lens in which a plurality of lenses is arranged like an array and configured to allow the light beam having passed through the rotating phase plate to pass,

wherein a portion in which a maximum size of the plurality of step regions is equal to or less than an arrangement pitch of the plurality of lenses and a portion in which the maximum size is larger than the arrangement pitch of the plurality of lenses are mixed.

7. An illuminating apparatus, comprising:

a light source configured to generate coherent light;

a rotating phase plate in which a plurality of step regions is arranged randomly and has a height equal to or less than a wavelength, and configured to change a phase of a light beam from the light source by allowing the light beam to pass therethrough; and

a plurality of fly'"'"'s eye lenses in which a plurality of lenses is arranged like an array, configured to have different arrangement positions from the rotating phase plate, and configured to allow the light beam having passed through the rotating phase plate to pass,

wherein a portion in which a first product of a maximum size of the plurality of step regions and an optical magnification from the rotating phase plate to a plane of incidence of one of the fly'"'"'s eye lenses is equal to or less than an arrangement pitch of the plurality of lenses of the one of the fly'"'"'s eye lenses and a portion in which the first product is larger than the arrangement pitch of the plurality of lenses of the one of the fly'"'"'s eye lens are mixed, and a portion in which where a second product of the maximum size of the plurality of step regions and the optical magnification from the rotating phase plate to the plane of incidence of the other of the fly'"'"'s eye lenses is equal to or less than the arrangement pitch of the plurality of lenses of the other of the fly'"'"'s eye lenses and a portion in which where the second product is larger than the arrangement pitch of the plurality of lenses of the other of the fly'"'"'s eye lenses are mixed.

8. The apparatus according to claim 7, further comprising:

a lens configured to be arranged between the plurality of fly'"'"'s eye lenses.

9. A pattern inspection apparatus, comprising:

a light source configured to generate coherent light;

a rotating phase plate in which a plurality of step regions is arranged randomly and has a height equal to or less than a wavelength of the light, and configured to change a phase of a light beam from the light source by allowing the light beam to pass therethrough;

a fly'"'"'s eye lens in which a plurality of lenses is arranged like an array and configured to allow the light beam having passed through the rotating phase plate to pass;

an optical image acquisition unit configured to acquire an optical image of a pattern by using the light beam having passed through the fly'"'"'s eye lens as illuminating light and by illuminating a substrate on which the pattern is formed with the illuminating light; and

a comparing unit configured to compare the optical image and a reference image,

wherein a portion in which a product of a maximum size of the plurality of step regions and an optical magnification from the rotating phase plate to a plane of incidence of the fly'"'"'s eye lens is equal to or less than an arrangement pitch of the plurality of lenses and a portion in which the product is larger than the arrangement pitch of the plurality of lenses are mixed.

10. A method of forming illuminating light, comprising:

generating coherent light from a light source;

changing a phase of a light beam from the light source by causing a rotating phase plate that has a plurality of step regions arranged randomly and having a height equal to or less than a wavelength formed thereon to pass the light beam from the light source; and

causing a fly'"'"'s eye lens in which a plurality of lenses is arranged like an array to pass the light beam having passed through the rotating phase plate,

wherein a relationship between the rotating phase plate and the fly'"'"'s eye lens, is configured to mix a portion in which a product of a maximum size of the plurality of step regions and an optical magnification from the rotating phase plate to a plane of incidence of the fly'"'"'s eye lens is equal to or less than an arrangement pitch of the plurality of lenses and a portion in which the product is larger than the arrangement pitch of the plurality of lenses.