Fly eye lens and proximity exposure machine optical system

Patent metadata

Field	Value
Publication number	US-9274433-B2
Application number	US-201314065647-A
Country	US
Kind code	B2
Filing date	Oct 29, 2013
Priority date	Dec 14, 2012
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

An embodiment of the present invention provides a fly eye lens which is applied to a proximity exposure machine optical system. The fly lens includes a first lens assembly and a second lens assembly, wherein the first lens assembly includes a plurality of lenses which form a first lens face, and the second lens assembly includes a plurality of lenses which form a second lens face. The first lens face is used to split an incident broad light beam into narrow light beams and then refract the narrow light beams onto the second lens face, and the second lens face is used to dispersively refract the received narrow light beams onto a concave mirror in the optical system. A lens closer to a center of the second lens face has a higher transmittivity, and a lens farther from the center of the second lens face has a lower transmittivity. According to the embodiment of the present invention, since different lenses on the second lens face have different transmittivities, the illuminances of light radiated to different regions of a mask plate through the fly eye lens are different, and thus the uniformity of the critical dimensions of the exposed patterns can be improved to a certain extent.

First claim

What is claimed is:

1. A fly eye lens applied to a proximity exposure machine optical system, comprising:
a first lens assembly which includes a plurality of lenses forming a first lens face; and
a second lens assembly which includes a plurality of lenses forming a second lens face,
wherein the first lens face is used to split an incident broad light beam into narrow light beams and then refract the narrow light beams onto the second lens face, and the second lens face is used to dispersively refract the received narrow light beams onto a concave mirror in the optical system,
among the plurality of lenses in the second lens assembly, a lens which is closer to a center of the second lens face has a higher transmittivity than a lens which is farther from the center of the second lens face.

2. The fly eye lens according to claim 1 , wherein transmittivities of the lenses in the second lens assembly are between 60% and 100%.

3. The fly eye lens according to claim 2 , wherein
a lens closest to the center of the second lens face in the second lens assembly has a highest transmittivity among the plurality of lenses forming the second lens face.

4. The fly eye lens according to claim 3 , wherein
a distance from each lens in the second lens assembly to the center of the second lens face is defined as a distance from a center of each lens in the second lens assembly to the center of the second lens face.

5. The fly eye lens according to claim 2 , wherein
a distance from each lens in the second lens assembly to the center of the second lens face is defined as a distance from a center of each lens in the second lens assembly to the center of the second lens face.

6. The fly eye lens according to claim 1 , wherein
the transmittivity of each lens in the second lens assembly can be obtained by the following formulae:

∑

i
,
j

⁢

⁢

T
ij

×

P
Eij

⁡

(

x
,
y

)

=

P
0

-

Δ
⁢

⁢
P

Δ
⁢

⁢
P

=

Δ
⁢

⁢
T

=

1
t

×

K
1

K
2

×
H
×

[

1
-

(

l
L

)

n

]

wherein T ij denotes a transmittivity of each lens in the second lens assembly,

∑

i
,
j

⁢

⁢

T
ij

×

P
Eij

⁡

(

x
,
y

)

denotes illuminance on the concave mirror onto which the second lens face refracts the received light beams,
P 0 denotes a known illuminance at a center of the concave mirror,
ΔP denotes a difference of the illuminance at the selected point other than the center and the illuminance at the center, on the concave mirror to which the second lens face refracts the received light beams,
ΔT denotes a difference of an illuminance at the selected point other than a center and an illuminance at the center, on a mask plate, to which the second lens face refracts the received light beams, in the optical system,
t, n, K 1 and K 2 are constants, 0<K 1 <1, 0<K 2 <1, and n>1,
l denotes a distance between the selected point other than the center on the mask plate and the center of the mask plate,
L denotes a distance between the center of the mask plate and an intersection, which is a point at which a straight line formed by connecting the selected point on the mask plate and the center of the mask plate intersects with an edge of the mask plate, on the edge of the mask plate, and
H denotes a maximum variation of amount of an exposure distance at the center of the mask plate.

7. The fly eye lens according to claim 6 , wherein
a distance from each lens in the second lens assembly to the center of the second lens face is defined as a distance from a center of each lens in the second lens assembly to the center of the second lens face.

8. The fly eye lens according to claim 1 , wherein
the transmittivities of the lenses in the second lens assembly are determined according to a bending degree of a mask plate caused by the proximity exposure machine optical system.

9. The fly eye lens according to claim 8 , wherein
a distance from each lens in the second lens assembly to the center of the second lens face is defined as a distance from a center of each lens in the second lens assembly to the center of the second lens face.

10. The fly eye lens according to claim 1 , wherein
a distance from each lens in the second lens assembly to the center of the second lens face is defined as a distance from a cente

Assignees

• Boe Technology Group Co Ltd
• Beijing Boe Display Tech Co

Inventors

• Li Min
• Wu Hongjiang
• Lee Gyuhyun
• Zhang Jikai
• Yang Tonghua

Classifications

• G03F7/7035

  Proximity or contact printers · CPC title

• G03F7/70058

  Mask illumination systems · CPC title

• G03F7/70075 Primary

  Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection · CPC title

• G03F7/70066

  Size and form of the illuminated area in the mask plane, e.g. reticle masking blades or blinds · CPC title

• G03F7/70083 Primary

  Non-homogeneous intensity distribution in the mask plane · CPC title