Nikon Corporation

Fujitsu Corporation

Nippon Kogaku K.k.

Koichi Ohno

Kinya Kato

Koichi Matsumoto

Kyoichi Suwa

Tetsuo Tachibana

Kazuo Ushida

Hiroki Tateno

Satoru Anzai

Toshiyuki Namikawa

Kenji Higashi

A bit rate control circuit of the present invention includes a timer controller and a memory. In one aspect of the present invention, words stored in the memory are addressed by addresses corresponding to data channels. Each of the words includes an enable flag, a set value and an operation value. The set values are determined based on bit rates assigned to the corresponding data channels. The words are scanned at constant intervals. The operation values are updated by adding one when the enable flag is active, in each scan, and if the updated operation value reaches the set value, a command to generate an ATM cell for the corresponding data channel is issued.

Apparatus for controlling ATM cell generation rate

The present invention provides a projection exposure apparatus comprising: a reticle stage; an illumination optical system for illuminating a reticle on the reticle stage; a stage on which a substrate is supported; and a projection optical system having a predetermined numerical aperture to project a pattern formed on the reticle and illuminated by the illumination optical system onto the substrate, and in which a longitudinal spherial aberration thereof regarding the focusing of the pattern formed on the reticle onto the substrate are excessively corrected.

Projection exposure apparatus

In a method and apparatus for highly precisely adjusting the optical performance including the imaging plane and the magnification factor of a projection lens in a projection optical apparatus, adjustment of the projection lens is achieved by changing the barometric pressure, i.e., the refractive index of at least one space which is located on an optical path and which is shielded from the outer atmosphere is changed by changing the barometric pressure therein. At this space, a space or gap present between any two adjacent elements of a plurality of lens elements or a group of lenses constituting a projection lens is preferably selected. The selected space is independent from and is shielded from the outer atmosphere by the lenses defining itself and a housing supporting these lenses, and is filled with air or a gas. The pressure of the air or gas inside the independent space is controlled by a barometric controller.

Method and apparatus for adjusting imaging performance of projection

An apparatus having stage means on which a substrate is placed, holding means for holding a mask formed with at least one mark, and exposing means for exposing the image of said at least one mark on the exposure surface of the substrate which is coated with photoresist includes displacing means for imparting relative displacement between the stage means and the holding means, control means for controlling the exposing means and the displacing means and executing first exposure and second exposure successively, the control means executing the first and the second exposure of exposing the image of said at least one mark on a plurality of predetermined areas of the exposure surface of the substrate placed on the stage means, and controlling the exposing means and the displacing means so that the amount of deviation between the position of the image of said at least one mark in each of the predetermined areas during the first exposure and the position of said image during the second exposure assumes a predetermined value, developing means for developing the substrate in response to the termination of the second exposure, deviation amount detecting means for detecting the amount of deviation between the position of the image of said at least one mark in each of the predetermined areas of the developed substrate during the first exposure and the position of said image during the second exposure and making a detection signal, and determining means for determining the accuracy of the apparatus in accordance with the detection signal and the predetermined value.

Method of and apparatus for detecting the accuracy of superposition

An optical apparatus for projecting a pattern on a first plane onto a second plane comprises a projection optical system disposed between the first plane and the second plane to form an imaging optical path, a structure for forming a space independent from the ambient space and filled with a gas between the first plane and the second plane in such a manner that the imaging optical path passes therethrough, the structure including a first transparent flat member perpendicular to the optic axis of the projection optical system and forming the entrance surface of the imaging light beam to the independent space and a second transparent flat member parallel to the first transparent flat member and forming the exit surface of the imaging light beam from the independent space, the gas filling the independent space having a refractive index different from the refractive index of the ambient space, and a device for regulating the distance between the first transparent flat member and the second transparent flat member and varying the thickness of the independent space in the direction of the optic axis.

Growing community of inventors

Yokohama, Japan

Koichi Ohno