Kabushiki Kaisha Toshiba

Shin-ichi Ito

Soichi Inoue

Takashi Sato

Keiji Horioka

Tadahito Fujisawa

Shuichi Tamamushi

Takayuki Iwamatsu

A projection exposure apparatus is constituted by a first focusing optical system for focusing light from a mercury-vapor lamp as a light source, a uniforming optical system for uniforming the focused light, a second focusing optical system for focusing the uniformed light and radiating the light onto a reticle mask, and a projection optical system for projecting the light, transmitted through the reticle, onto a wafer. The apparatus is designed to project/expose a predetermined mask pattern, formed on the mask, onto the wafer through the projection optical system. A special stop (i.e., a four-eye filter) is arranged as a secondary source for uniformly illuminating the mask. The special stop serves to set an intensity distribution within the exit plane of the secondary source such that intensities in four regions quadruple-symmetrical about the optical axis of the secondary source and decentered therefrom are higher than intensities in other regions. A translucent pattern is formed as the mask on a light-transmitting substrate. The phase difference between light passing through the translucent film and light passing through the light-transmitting substrate is represented by 180.times.(2n+1).+-.30 (degree) (where n is an integer). In addition, the apparatus includes a halftone mask which allows an amplitude transmittance T of the translucent film and an amplitude transmittance T0 of the light-transmitting substrate to satisfy 0.01.times.T0.ltoreq.T.ltoreq.0.30.times.T0. Furthermore, a projection exposure apparatus is provided, in which a light source and a secondary source is coupled to each other through fibers, and an optical modulator is inserted therebetween so that the spatial distribution of light amounts can be electrically and optically controlled.

Filter manufacturing apparatus

There is disclosed a mask for light exposure which comprises being provided with a light transparent substrate and a mask pattern formed on the light transparent substrate, the mask pattern comprising a light screening pattern composed of a material which screens the exposure light and transmits the light having the longer wavelength than that of the exposure light and a phase shift pattern formed by engraving a part of the light transparent substrate.

Mask for light exposure and process for production of the same

An exposure mask is formed by providing a mask pattern including a transparent phase shift pattern and a translucent phase shift pattern on a light-transmissive substrate. Each of the transparent phase shift pattern and the translucent phase shift pattern causes a relative phase difference of 180.degree. to exposure light passing through each of the transparent phase shift pattern against exposure light passing through the light-transmissive substrate and the translucent phase shift pattern. The transparent phase shift pattern and the translucent phase shift pattern partly overlap each other. At least one opening portion in the mask pattern has at an adjacent region an overlap region of the transparent phase shift pattern and the translucent phase shift pattern region. A region of the translucent phase shift pattern is provided on the outside of the overlap region.

Exposure mask comprising transparent and translucent phase shift patterns

A projection exposure apparatus is constituted by a first focusing optical system for focusing light from a mercury-vapor lamp as a light source, a uniforming optical system for uniforming the focused light, a second focusing optical system for focusing the uniformed light and radiating the light onto a reticle mask, and a projection optical system for projecting the light, transmitted through the reticle, onto a wafer. A special stop is arranged as a secondary source for uniformly illuminating the mask. The special stop serves to set an intensity distribution within the exit plane of the secondary source so that intensities of both peripheral and central portions are larger than an intensity of an intermediate portion. In addition, the apparatus includes a halftone mask which allows an amplitude transmittance T of the translucent film and an amplitude transmittance T0 of the light-transmitting substrate to satisfy 0.01.times.TO&lt;or=T&lt;or=0.30.times.TO. The phase difference between light passing through the light-transmitting substrate is represented by 180.times.(2n+1)+or -30 (degree) (where n is an integer).

Projectin exposure apparatus

A projection exposure apparatus is constituted by a first focusing optical system for focusing light from a mercury-vapor lamp as a light source, a uniforming optical system for uniforming the focused light, a second focusing optical system for focusing the uniformed light and radiating the light onto a reticle mask, and a projection optical system for projecting the light, transmitted through the reticle, onto a wafer. The apparatus is designed to project/expose a predetermined mask pattern, formed on the mask, onto the wafer through the projection optical system. A special stop (i.e., a four-eye filter) is arranged as a secondary source for uniformly illuminating the mask. The special stop serves to set an intensity distribution within the exit plane of the secondary source such that intensities in four regions quadruple-symmetrical about the optical axis of the secondary source and decentered therefrom are higher than intensities in other regions. A translucent pattern is formed as the mask on a light-transmitting substrate. The phase difference between light passing through the translucent film and light passing through the light-transmitting substrate is represented by 180.times.(2n+1).+-.30 (degrees) (where n is an integer). In addition, the apparatus includes a halftone mask which allows an amplitude transmittance T of the translucent film and an amplitude transmittance T0 of the light-transmitting substrate to satisfy 0.01.times.T0.ltoreq.T.ltoreq.0.30.times.T0. Furthermore a projection exposure apparatus are provided, in which a light source and a secondary source is coupled to each other through fibers, and an optical modulator is inserted therebetween so that the spatial distribution of light amounts can be electrically and optically controlled.

Projection exposure apparatus

An exposure mask according to the invention comprises a light-transmissive substrate, and mask patterns formed on the light-transmissive substrate, and including transparent phase shift patterns and translucent phase shift patterns, each of the translucent phase shift patterns having a phase difference of at least 180.degree. for exposure light corresponding to an optical path difference between a transparent portion of the light-transmissive substrate and a transparent portion of the transparent phase shift pattern, the transparent phase shift patterns and translucent phase shift patterns overlapping with each other, wherein the mask patterns include pattern groups each having a first region consisting of an exposed portion of the light-transmissive substrate, a second region adjacent to the first region, in which only a corresponding one of the translucent phase shift patterns exists, a third region adjacent to the second region, in which a corresponding one of the transparent phase shift patterns is laminated on the corresponding translucent phase shift pattern, and a fourth region adjacent to the third region, in which only the corresponding transparent phase shift pattern exists.

Exposure mask

This invention provides an exposure mask having mask patterns formed on a transparent substrate, the mask patterns including translucent phase shift patterns having a light path length for exposure light differentiated by 180.degree. from that of transparent areas of said transparent substrate and transparent phase shift patterns. Such an exposure mask can be advantageously used to realize highly defined patterns.

Growing community of inventors

Yokohama, Japan

Shin-ichi Ito