Nikon Corporation

Masaki Yamamoto

Hiroyuki Kondo

Katsuhiko Murakami

Noriaki Kandaka

Tetsuya Oshino

Katsumi Sugisaki

A multilayer film reflector capable of simply correcting a wavefront phase and a method of forming the reflector are disclosed. For this purpose, a reflector using reflection by a multilayer film is disclosed. This multilayer film is formed in a number of cycles larger than that necessary to substantially saturate a reflectance, and a wavefront phase of emerging rays is adjusted by cutting away the multilayer film in accordance with an amount of adjustment of the wavefront phase. Further, the formation of a correction film as well as the formation of a multilayer larger than necessary to substantially saturate the reflectance permits the correction of a phase by cutting away also the multilayer film when the phase cannot be corrected only by cutting away the correction film, whereby the phase can be corrected more accurately.

Optical element such as multilayer film reflection mirror, production method therefor and device using it

Apparatus and methods are disclosed for milling selected regions on the surface of a multilayer-film reflective surface of an X-ray mirror to correct the reflected wavefront produced by the mirror, thereby producing a more uniform or otherwise more desirable phase distribution of the reflected wavefront. The milled multilayer films include multiple lamina sets each including respective layers of at least two respective substances. The layers usually are 'stacked' alternatingly at a fixed period length on a mirror substrate. By selectively removing one or more surficial layers in selected locations, local corrections of the phase shift of the reflective wavefront are achieved. At each milling location, the depth profile can be stepwise or smoothly gradated. Milling methods can include lapping, ion-beam bombardment, plasma-enhanced chemical vapor machining (CVM), reactive-ion etching, photochemical reactions, or laser ablation.

Apparatus and methods for surficial milling of selected regions on surfaces of multilayer-film reflective mirrors as used in X-ray optical systems

Methods are disclosed for manufacturing multi-layer film reflection mirrors, in which a desirable shape accuracy of a reflected wavefront can be obtained after locally scraping the multi-layer film. In an exemplary method, a multi-layer film (comprising respective alternating layers of at least two types of substances having different respective refractive indices) is superposedly formed on the surface of a mirror substrate. The multi-layer film has a constant period length, and the multi-layer film on the substrate is locally scraped to correct a phase of a reflected wavefront from the reflective surface of the mirror. The multi-layer film has an internal stress of 50 MPa or smaller. Alternatively or in addition, a compensating adjustment in a film formed on a reverse surface of the substrate can be made to cancel the stress perturbation caused by scraping of the multi-layer film on the obverse surface of the substrate.

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Sendai, Japan

Masaki Yamamoto