Nikon Corporation

Kabushiki Kaisha Toyota Chuo Kenkyusho

Hiroshi Niikura

Tomoyoshi Motohiro

Yasuhiko Takeda

Shoji Noda

Tatsumi Hioki

Mikio Okamoto

Masaaki Mochida

Yutaka Yamaguchi

Atsushi Yanagisawa

A method for evaluating the refractive index homogeneity of an optical member includes passing light through an optical member () used for photolithography. The side surface () with respect to the optical axis (AX) of the optical member () is retained by elastic members () at a plurality of positions disposed at equal intervals to pass light through the optical member () and measure a wave front aberration. The optical member is rotated around the optical axis (AX) by the equal interval to measure a wave front aberration again and determine the difference from the initial measurement. The optical member () is moved in a direction perpendicular to the optical axis (AX) to measure a wave front aberration again and determined the difference from the initial measurement. The refractive index homogeneity of the optical member can be accurately evaluated from those differences by using fitting of the Zernike cylindrical function.

Method for evaluating refractive index homogeneity of optical member

A unit for measuring optical properties. The unit includes the first through sixth reflecting surfaces, a reflecting surface rotating device and an object moving device. In order to accurately measure transmittance, reflectance and phase change in transmittance or reflection of optical elements, especially transmittance of a thick object, the first through the fourth reflecting surfaces M1-M4 are arranged so that an optical path formed by the reflecting surfaces M1-M4 has a shape like an 'N' letter and so that light of incidence L1 has the same optical axis as exit light L2. An optical center O is a point that a line segment that connects a point of incidence A with an exit point D intersects an optical path that connects the reflecting surface M2 with the reflecting surface M3. The reflecting surface M2 is an ellipsoid of revolution having foci of the optical center O and the point of incidence A. The reflecting surface M3 is an ellipsoid of revolution having foci of the optical center and the exit point D. A reflecting surface rotating device rotates M4 at the exit point D in conjunction with the reflecting surface M1 that is rotated at the point of incidence A. The reflecting surface M5 is a parabolic mirror that makes light reflected from the reflecting surface M1 parallel. M6 is a parabolic mirror that converges light reflected from the reflecting surface M5 onto the reflecting mirror M4.

Unit for measuring optical properties

By providing a normally deposited layer as a buffer layer between a substrate and an obliquely deposited layer, it is possible to prevent contaminants on the substrate from diffusing into the obliquely deposited layer. Also, by providing a normally deposited layer as a passivation layer on the uppermost obliquely deposited layer, absorption of water vapor in the air by the obliquely deposited layer is prevented. Further, by forming a laminated object comprising obliquely deposited layers and dense normally deposited layers, strength of each obliquely deposited layer itself is increased and relaxation of its columnar structure can be suppressed with certainty because both the diffusion of contaminants from the substrate and the absorption of water in the air is prevented. Thus, by removing factors to accelerate the relaxation of columnar structure in the obliquely deposited layer, clouding of the obliquely deposited film layer can be prevented.

Obliquely deposited film element

Growing community of inventors

Chigasaki, Japan

Hiroshi Niikura