Reflection mask, method of producing mask and method of forming pattern using the mask
First Claim
1. A reflection mask used for optically forming patterns, comprising:
- a plurality of optically reflective surfaces for reflecting at least one of ultraviolet rays and X-rays of a wavelength, said reflective surfaces having different levels to change the phase relationship between rays respectively reflected by said reflective surfaces of different levels;
wherein said reflective surfaces each consist of a multilayer mirror; and
wherein the different levels between adjacent ones of said reflective surfaces correspond to one-half the period of the multilayer of the multilayer mirror.
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Accused Products
Abstract
By using a reflection mask for reflective reduction projection exposure which uses vacuum ultraviolet rays or soft X-rays of wavelength λ, there is enhancement of the resolution of the projection exposure by making the height of adjacent or neighboring reflective surfaces to be deviated by about (2n-1) xλ/(4 cos Θ) (where n=1, 2, 3, - - - ) with respect to the angle Θ subtended by the normal to the above reflective surfaces and the direction of incidence of the ultraviolet rays or the soft X-rays, thus inverting the phases of the vacuum ultraviolet rays or the soft X-rays reflected by the neighboring reflection regions. Therefore, the applicable range of the reduction projection exposure can be extended to 0.1 um or smaller.
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Citations
15 Claims
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1. A reflection mask used for optically forming patterns, comprising:
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a plurality of optically reflective surfaces for reflecting at least one of ultraviolet rays and X-rays of a wavelength, said reflective surfaces having different levels to change the phase relationship between rays respectively reflected by said reflective surfaces of different levels; wherein said reflective surfaces each consist of a multilayer mirror; and wherein the different levels between adjacent ones of said reflective surfaces correspond to one-half the period of the multilayer of the multilayer mirror. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of forming a photoreactive surface pattern on an integrated circuit portion during the fabrication of at least LSI, comprising the steps of:
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forming a beam of soft X-rays of a wavelength λ
;providing a mask substrate formed of different surfaces in the pattern so that the height of the surfaces that are adjacent each other differ by about (2n-1)×
λ
/(4 cos θ
) (wherein n=1, 2, 3, - - - ), and wherein the angle θ
is subtended by a normal to said different surfaces and the direction of incidence of the soft X-rays;providing as deposits on the different surfaces multi-layer soft X-ray mirrors as respective different level adjacent reflective surfaces, respectively differing in level corresponding to one-half the period of the multi-layer of the multi-layer mirror to thereby provide a reflection mask; projecting the beam simultaneously on adjacent reflective surfaces of the reflection mask at the substantial acute angle θ
that is subtended by a normal to the reflective surfaces and the direction of incidence of the beam to the reflective surfaces, while maintaining the reflective surfaces respectively differing in level sufficiently to phase shift different portions of the beam as they are reflected from the surfaces so that the phase of the adjacent reflected different portions of the beam will be inverted with respect to each other after reflection from the respective reflective surfaces;passing the reflected portions of the beam through a reduction reflecting optical system and optically reducing the reflected portions of the beam to produce reduced adjacent portions of the beam; projecting the reduction adjacent portions of the beam onto a workpiece substrate for exposing a surface layer of the workpiece substrate; and forming an integrated semiconductor circuit using the exposed surface layer. - View Dependent Claims (13)
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14. A method of forming a mask for radiation of wavelength λ
- to produce a photoreactive surface pattern on an integrated circuit portion during the fabrication of at least LSI, comprising the steps of;
throughout a mask substrate, forming surfaces in the pattern so that the height of the surfaces that are adjacent each other differ by about (2n-1)×
λ
/(4 cos θ
) (wherein n=1, 2, 3, - - - ), and wherein the angle θ
is subtended by a normal to said reflective surfaces and the direction of incidence of the radiation of a wavelength λ
; anddepositing on the surfaces multi-layer soft X-ray mirrors as different level adjacent reflective surfaces respectively differing in level corresponding to one-half the period of the multi-layer of the multi-layer mirror. - View Dependent Claims (15)
- to produce a photoreactive surface pattern on an integrated circuit portion during the fabrication of at least LSI, comprising the steps of;
Specification