Canon Kabushiki Kaisha

Fujitsu Corporation

Yasuhisa Sato

Yasuyuki Yamada

Hiroki Nakayama

Kouji Oizumi

Sadahiko Tsuji

Hideo Yokota

Masaki Okuno

Kazuo Fujibayashi

Katsumi Tanaka

Akira Tajima

Kazuo Ishikawa

Toshiro Nakanishi

Rinji Sugino

Yukiharu Ono

Susumu Matsumura

Keiji Ikemori

Nozomu Kitagishi

Takayuki Tsuboi

Isao Nakazawa

Takashi Matsushita

Takushi Motoyama

Shinya Yomogizawa

Yoshihiro Harunari

Kouji Oizumu

A dry cleaning method for removing metal contaminants from a surface of an oxide film such that no substantial etching of the oxide film occurs, includes the steps of supplying a halide gas containing an element that is selected from the group IIIa elements, group IVa elements and the group Va elements in a form of halide, to the oxide film, thereby dry cleaning the surface of the oxide film.

Dry cleaning process for cleaning a surface

A method of forming a silicon oxide film by setting a silicon wafer in a chamber capable of introducing oxidizing gas and being evacuated and by heating the silicon wafer in an oxidizing atmosphere. The method includes the steps of: transporting the silicon wafer into the chamber without contacting the silicon wafer with air; introducing an ozone containing gas into the chamber and setting the interior of the chamber to a predetermined pressure; and heating the silicon wafer to a predetermined temperature and oxidizing the surface of the silicon wafer. The predetermined pressure is preferably between 200 Torr and 0.1 Torr. Ozone may be generated from oxygen by applying ultraviolet rays to the upper space of a silicon wafer. The temperature of ozone to be introduced is preferably low. It is preferable to incorporate infrared heating in order not to excessively heat ozone and to heat a silicon wafer to a high temperature.

Method of forming thin silicon oxide film with high dielectric breakdown

A dry cleaning process for removing metal contaminants from a surface of an oxide film includes the steps of: forming a reaction area on the oxide film such that a silicon surface is formed in correspondence to the reaction area, supplying a dry cleaning gas selected from a group essentially consisting of chlorine, bromine, hydrogen chloride, hydrogen bromide and a mixture thereof, to the oxide film including the reaction area, to produce silicon halide molecules as a result of a reaction between the dry cleaning gas and the silicon surface, supplying the silicon halide molecules to a surface of the oxide film, and removing metal elements existing on the surface of the oxide film as a result of a reaction between the metal element and the dry cleaning gas under a presence of the silicon halide molecules.

A method of forming a non-volatile semiconductor memory device includes the steps of forming a generally periodical undulation on a surface of a silicon substrate with a pitch of 1-20 nm, by cleaning the surface of the substrate by a cleaning solution to form a native silicon oxide film that covers the surface of the silicon substrate with a thickness that changes generally periodically, followed by a selective etching process applied to the native silicon oxide film thus formed to expose the surface of the silicon substrate, and forming a tunneling oxide film on the undulated surface of the substrate by applying a thermal oxidation such that the tunneling oxide film has a thickness that changes generally periodically with a pitch of 1-20 nm.

Method of making a semiconductor memory device having a floating gate

A zoom lens comprising, from front to rear, a first lens unit of negative power, a second lens unit of positive power and a third lens unit of negative power, the second and third lens units being moved to effect zooming, and the third lens unit having its focal length f.sub.3 laid in the following range:

Compact zoom lens

A method of manufacturing a semiconductor integrated circuit comprises steps of forming at least one semiconductor device on a substrate, depositing an insulator layer on the substrate so as to bury the semiconductor device, providing a contact hole through the insulator layer for exposing a desired part of the semiconductor device, filling the contact hole by a refractory metal for electrical connection, covering the insulator layer by a second insulator layer, forming a groove through the second insulator layer according to a predetermined interconnection pattern such that the groove passes at least one contact hole and such that a top surface of the refractory metal filling the contact hole and a top surface of the first insulator layer are exposed by the groove, forming a material layer acting as nuclei for crystal growth of a second refractory metal at a bottom of the groove substantially continuously along the groove, and depositing the second refractory metal in the groove until the groove is substantially filled by a conductor of the second refractory metal.

Method of manufacturing a semiconductor integrated circuit having an

A photographic optical device of this invention comprises: a master lens unit having a positive refractive power, determining a photographic optical path and moving along the optical axis to change magnification; a first auxiliary lens unit having a positive refractive power and being capable of being placed on and off the optical path; and a second auxiliary lens unit having a negative refractive power and being capable of being placed on and off the optical path. The first auxiliary lens unit is attached to an image-plane side of the master lens unit to form a photographic unit giving a low ratio of magnification. The second auxiliary lens unit is attached to an image-plane side of the master lens unit to form another photographic unit giving a high ratio of magnification. The first and second auxiliary lens units are placed outside of the optical path to form another photographic unit giving a middle ratio of magnification.

Photographic optical device with variable magnification

A magnification change-over device for a camera is provided with an incident optical path for the incidence of the light of an object to be photographed; a first optical path for guiding the object light incident on the incident optical path to a first aperture; a second optical path for guiding the object light incident on the incident optical path to a second aperture; changeover means for selection between the first and second optical paths; and optical means for differentiating the magnification of an image formed through the second aperture from that of an image formed through the first aperture.

Magnification change-over device for camera

The disclosed variable magnification finder includes, from front to rear, a first lens unit of negative power, a second lens unit of positive power, a third lens unit of positive power, the first, second and third lens units constituting an objective lens of positive power, and an eyepiece of positive power. The first and second lens units form a finder image on a plane just in front of the third lens unit. The second lens unit is moved axially forward to increase the image magnification, while the shift of diopter of the finder is simultaneously compensated for by moving the first lens unit.

Finder of variable magnification

A changeover type variable magnification optical system whose focal length is changed by locating an auxiliary lens on the image side of a master lens assembly. The system satisfies following inequalities of:

Variable magnification optical system

A zoom lens including a first lens unit of positive power and a second lens unit of negative power with the axial separation therebetween varies to bring about zooming. The first lens unit includes at least one positive lens and at least one negative lens and the second lens unit consists of a forwardly concave negative meniscus lens, thereby making the lens system small.

Small sized zoom lens

A variable magnification finder including from front to rear, a first lens unit of negative power, a second lens unit of positive power and a third lens unit of positive power, these three units constituting an objective lens of positive overall power, followed by an eyepiece lens of positive power, wherein a finder image formed by the first and second units near the third lens unit is observed by the eyepiece lens, and, with the other lens units being held stationary, the second lens unit is axially moved to vary the finder magnification.

Finding device of variable magnification

A conversion lens for attachment to the rear of a master lens to increase the focal length of the entire system, includes a positive lens, and a negative lens positioned on the image side of the positive lens, wherein at least one of the lens surfaces of the positive lens and the negative lens is an aspherical surface.

Conversion lens releasably attached behind master lens

A view finder having, from front to rear, a first lens unit of negative power, a second lens unit of positive power and a third lens unit of negative power, the second lens unit being moved axially forward as the magnification varies from the smallest to the largest value, while the first lens unit is moved to compensate for the diopter shift resulting from the variation of the magnification.

View finder of variable magnification

A variable power finder having an objective lens of positive refracting power comprising a first lens unit of positive refracting power movable along an optical axis and a second lens unit releasably attached to the first lens unit in axial alignment, wherein a real image to be observed is formed by the objective lens.

Growing community of inventors

Kanagawa, Japan

Yasuhisa Sato