Patent Application
20160370564
A lithography mirror set is an important secondary system for a lithography lens set for manufacture of electronic devices. However, the currently available lithography lens sets are all full refractive lens and long optical extended lens. The former has a large volume. The latter may reduce the number of devices, but it adopts multiple faces and thus involves a difficult manufacture and assembly.
The long optical extended lithography lens set may be seen in the ASML fashion manufactured by a Germany company ZEISS, with the counterpart patents DE9355198 and DE19922209; and in the folded symptotic curvature fashion manufactured by a Japan company NIKON, as shown in
In addition, to save the used material, a French company Thales Group adopts the DYSON return fashion to reduce a light path, so that the light returns back and forth in the mirror sets 40, 50, also seen in its counterpart Chinese patent CN101171546. Thus, the number of mirrors 40, 50 may be reduced. However, the mirror sets 40, 50 and the reflecting faces 20, 22 have to be non-spherical faces, as shown in
A lithography mirror set is an important secondary system for a lithography lens set for manufacture of electronic devices. However, the currently available lithography lens sets are all full refractive lens and long optical extended lens. The former has a large volume. The latter may reduce the number of devices, but it adopts multiple faces and thus involves a difficult manufacture and assembly.
The long optical extended lithography lens set may be seen in the ASML fashion manufactured by a Germany company ZEISS, with the counterpart patents DE9355198and DE19922209; and in the folded symptotic curvature fashion manufactured by a Japan company NIKON, as shown in
In addition, to save the used material, a French company Thales Group adopts the DYSON return fashion to reduce a light path, so that the light returns back and forth in the mirror sets 40, 50, also seen in its counterpart Chinese patent CN101171546. Thus, the number of mirrors 40, 50 may be reduced. However, the mirror sets 40, 50 and the reflecting faces 20, 22 have to be non-spherical faces, as shown in
It is, therefore, an object of the present invention to overcome the issues encountered in the prior art and set forth a conjugate common light path lithography lens set which adopts a spherical and folded assembly in which each of four spherical mirrors and reflecting mirrors all have a spherical surface, a omni-spherical mirror set and two kinds of optical material are mutually arranged to form the novel conjugate common light path lithography lens set.
It is a secondary object of the present invention to set forth a conjugate common light path lithography lens set, which may further achieve the function of the lithography lens, and have a direct effect on the manufacturing cost, and further have the efficacies of reduced component number, easier manufacture of the optical components (satisfied with the lens manufacturing's experience equation), easier calibration, reduced chromatic abberation, optimized aperature F/#, and a reduced cost.
According to the present invention, the conjugate common light path lithography lens set, comprising a spherical mirror set, comprising a first spherical mirror, a second spherical mirror, a third spherical mirror, and a fourth spherical mirror arranged sequentially, the first and second spherical mirrors providing a curvature and a calibrated planatism, and the third and fourth spherical mirror being used to calibrate an astigmatism and a curvature of field; a spherical reflecting mirror, arranged below the fourth spheircal mirror, to reflect a light path and control a dimension of a numerical aperture; a first and second planar reflecting mirrors, inclinedly arranged above the first spherical mirror to guide a light path, so that a conjugate telecentric component pattern is formed by the spherical mirror set, the spherical reflecting mirror, and the first and second planar reflecting mirrors so as to maintain an pattern of an object to have a non-deformed pattern after experiencing the spherical mirror set, the spherical reflecting mirror, and the first and second planar reflecting mirrors.
In an embodiment, the first, second and third spherical mirrors are each a positive curvature mirror.
In an embodiment, the fourth spherical mirror is a concave lens set and a concaved reflecting mirror.
In an embodiment, the first, second, third, and fourth spherical mirrors are arranged in such an order so that a chromatic abberation is calibrated.
In an embodiment, the object is a mask.
In an embodiment, the pattern of the object is outputted after experiencing the first planar reflecting mirror, the first, second, third, fourth spherical mirrors, the spherical reflecting mirror, the fourth, third, second and first spherical mirrors, and the second planar reflecting mirror.
In an embodiment, the conjugate common light path lithography lens set is applied to collimated image projection device.
The present invention will be better understood from the following detailed descriptions of the preferred embodiments according to the present invention, taken in conjunction with the accompanying drawings, in which:
Referring to
As shown, the present invention is a conjugate light path lithography lens set, which uses a common optical path to reduce a number of optical components required. The conjugate common light path lithography lens set comprises four spherical mirrors 11-14, a spherical reflecting mirror 15, and two planar reflecting mirrors 16, 17.
The four spherical mirrors 11-14 includes a first spherical mirror 11, a second spherical mirror 12, a third spherical mirror 13, and a fourth spheircal mirror 14. The first, second, and third spherical mirrors 11, 12, 13 are each a positive curvature mirror, while the fourth spherical mirror 14 is a concave lens set and a concaved reflecting mirror.
The first and second spherical mirrors 11, 12 each provide a curvature and a calibrated planatism, and the third and fourth spherical mirror 13, 14 are used to calibrate an astigmatism and a curvature of field. Further, the first, second, third, and fourth spherical mirrors 11, 12, 13, 14 have their material orders for calibrating a chromatic abberation.
The spherical reflecting mirror 15 is arranged below the fourth spherical mirror 14 to reflect the light path and control a mimension of a numerical aperture.
The two planar reflecting mirrors 16, 17 comprises a first planar reflecting mirror 16, and a second planar reflecting mirror 17, which are inclinedly arranged above the first spherical mirror 11 to guide a light path. In this manner, a conjugate telecentric component pattern is formed by the spherical mirror set, the spherical reflecting mirror, and the first and second planar reflecting mirrors so as to maintain an pattern of an object to have a non-deformed pattern after experiencing the above optical components. As such, the novel conjugate common light path lithography lens set is completed.
The conjugate common light path lighography lens set may be well applicable to a collimated image projection device. In this case, the object is a mask 1. In operation, the mask 1 has its pattern to be outputted on an image forming face 2 through the first planar reflecting mirror 16, the first, second, third and fourth 11, 12, 13, 14, the spherical reflecting mirror 15, the fourth spherical mirror 14, the third spherical mirror 13, the second spherical mirror 12, the first spherical mirror 11, and the second planar reflecting mirror 17 sequentially.
The lithography lens set is one of the main assemblies in the lighography set, and used to project a mask onto an image forming face by using its lens, where the optical lens is required to have its resolution up to a diffraction limit and a deformity below 0.01% of a maximum field angle.
For this, several embodiments are set forth for tests of diffraction modulation transfer functions (MTFs).
Viewing from the above results in
In this manner, a spherical and folded assembly is adopted, where each of the four spherical mirrors and the reflecting mirror all have a spherical surface, and the omni-spherical mirror set and two kinds of optical material are mutually arranged to form the novel conjugate common light path lithography lens set. This may further achieve the function of the lithography lens, and have a direct effect on the manufacturing cost.
In addition, the present invention has the efficacies of reduced component number, easier manufacture of the optical components (satisfied with the lens manufacturing's experience equation), easier calibration, reduced chromatic abberation, optimized aperature F/#, and a reduced cost.
In summary, the present invention is a conjugate common light path lighography lens set, which may effectively improve the demerits encountered in the prior art, the omni-spherical mirror set and two kinds of optical material are mutually arranged to form the novel conjugate common light path lithography lens set. This may further achieve the function of the lithography lens, and have a direct effect on the manufacturing cost. And, the efficacies of reduced component number, easier manufacture of the optical components (satisfied with the lens manufacturing's experience equation), easier calibration, reduced chromatic abberation, optimized aperature F/#, and a reduced cost may be achieved.
From all these views, the present invention may be deemed as being more effective, practical, useful for the consumer's demand, and thus may meet with the requirements for a patent.
The above described is merely examples and preferred embodiments of the present invention, and not exemplified to intend to limit the present invention. Any modifications and changes without departing from the scope of the spirit of the present invention are deemed as within the scope of the present invention. The scope of the present invention is to be interpreted with the scope as defined in the claims.
