Canon Kabushiki Kaisha

Ryuji Biro

Yasuyuki Suzuki

Kenji Ando

Minoru Otani

Hidehiro Kanazawa

Masaaki Matsushima

Toshiaki Shingu

Hirotaka Fukushima

There is to provide an optical element fabrication method including the steps of forming a thin film onto a substrate, and eliminating a color center produced in the forming step by giving energy to the substrate.

Optical element fabrication method, optical element, exposure apparatus, device fabrication method

In an anti-reflective film including alternating layers of high refractive-index layers and low refractive-index layers, by designing such that a designed central wavelength &#x3bb;is within a wavelength range of 141 nm to 189 nm, and that when the first to eighth layers as counted from a substrate have optical film thicknesses dto drespectively, the equations of:0.45&#x3bb;&#x2266;d&#x2266;0.65&#x3bb;;0.05&#x3bb;&#x2266;d&#x2266;0.20&#x3bb;;0.29&#x3bb;&#x2266;d&#x2266;0.49&#x3bb;;0.01&#x3bb;&#x2266;d&#x2266;0.15&#x3bb;;0.05&#x3bb;&#x2266;d&#x2266;0.20&#x3bb;;0.23&#x3bb;&#x2266;d&#x2266;0.28&#x3bb;;0.23&#x3bb;&#x2266;d&#x2266;0.28&#x3bb;; and0.23&#x3bb;&#x2266;d&#x2266;0.28&#x3bb;are satisfied, the anti-reflective film can be formed so as to have a low reflectance for a light incident at such a large angle as 30 degrees or more, without increasing the whole thickness of the film.

Anti-reflective film and optical element having anti-reflective film

The present invention provides a method for forming a film of aluminum oxide in which a target containing aluminum is sputtered in a gas containing fluorine atoms. The thin film of aluminum oxide according to the present invention has little optical absorption and high refractive index in the ultraviolet and vacuum ultraviolet regions.

Method for forming thin films

In order to provide an antireflection film of a wide wavelength bandwidth excellent in environment resistance performance in the ultraviolet wavelength region, the antireflection film is constructed in four-layered, or five-layered, or six-layered structure, using Al O for high-index layers and AlF or MgF for low-index layers. Vacuum evaporation, sputtering, or CVD is used for formation of the antireflection film.

Antireflection film, optical element with antireflection film, and production method of the antireflection film

A process of producing a thin film is disclosed. The process comprises the steps of providing a vessel; placing a target such that a surface to be sputtered of the target surrounds a discharge space; placing a substrate on a side of an opening of the space such that the substrate faces an anode disposed so as to close another opening of the space surrounded by the target; supplying a sputtering gas and a fluorine-containing gas into the vessel; and supplying a dc power or a power obtained by superimposing pulses with reversing polarities on the dc power, between the target and the anode, wherein a discharge is induced in the discharge space to sputter the target, thereby forming a fluorine-containing thin film on the substrate.

Thin film production process and optical device

The antireflection film of the present invention comprises an alternately multi-layered film of 10 layers formed on a base member and having antireflection characteristics in two wavelength regions including a first wavelength (&lgr; ) of 248 nm and a second wavelength (&lgr; ) of 633 nm as central wavelengths, respectively, the multi-layered film of 10 layers comprising: low-refractive index layers arranged at odd-numbered positions from a side opposite to the base member and having a refractive index of 1.45 to 1.52 at the first wavelength (&lgr; ); and high-refractive index layers arranged at even-numbered positions from the side opposite to the base member and having a refractive index of 1.65 to 1.80 at the first wavelength (&lgr; ), wherein layers arranged at the first, second and third positions from the side opposite to the base member each have an optical thickness ranging from 0.21&lgr; to 0.28&lgr; .

Antireflection film and optical element coated with the antireflection film

A film formation method of forming at least one layered film on a substrate containing fluorite as a main ingredient by using a film formation apparatus which emits electrons or ions, which comprises the step of forming, as a first layered film counted from the side of the substrate, a film having a thickness of 30 nm or less and comprising at least one selected from the group consisting of SiO,, BeO, MgO, and MgF,.

Optical element with substrate containing fluorite as main ingredient, and method and apparatus for producing the optical element

A process is provided for forming a thin film having refractive index thereof varying continuously or stepwise in a thickness direction. The process comprises sputtering in a vacuum chamber by introducing, during film formation, at least two kinds of gases selected from a nitrogen-containing gas, an oxygen-containing gas, and a fluorine-containing gas with the flow rate ratio of the gases varied continuously or stepwise. This process enables variation of the refractive index in the thickness direction, simply without difficulty.

Process for thin film formation by sputtering

In a method for forming a multi-layer optical thin film on a surface of a base material, a multi-layer optical thin film is formed based on thickness setting values for respective layers, an optical characteristic of the thus formed multi-layer optical thin film is measured, thicknesses for the respective layers for a multi-layer optical thin film to have an aimed optical characteristic are obtained based on the thus measured optical characteristic, the thickness setting values are corrected based on the thus obtained film thicknesses for the respective layers, and a next multi-layer optical thin film is formed based on the thus corrected thickness setting values. In another method for forming a thin film by sputtering, a concentration of H.sub.2 O gas in a vacuum chamber or a discharge impedance is measured, and at least one of sputter power, sputter gas partial pressure, and sputter gas flow rate is controlled in accordance with the measurement result so as to keep the sputtering rate constant.

Method for forming thin film

An anti-reflection film is arranged by alternately stacking a plurality of high-refractive index layers containing Al.sub.2 O.sub.3 and a plurality of low-refractive index layers containing SiO.sub.2 on a transparent substrate in turn from the substrate side to the air side, and satisfies:

Anti-reflection film and optical system using the same

This specification discloses antireflection film and an exposure apparatus using the same. The exposure apparatus has an optical system, and antireflection film formed on the refracting surface of the optical system, the antireflection film having a high refractive index layer having Al.sub.2 O.sub.3 or Ta.sub.2 O.sub.5 and a low refractive index layer having SiO.sub.2.

Growing community of inventors

Kawasaki, Japan

Ryuji Biro