Samsung Electronics Co., Ltd.

Seong-oon Choi

Woo-Sung Han

Cheol-hong Kim

Ho-Young Kang

Chang-jin Sohn

A projection method uses a modified illumination method for a lithography process of semiconductor device, and a projection system and mask use the projection method. An object is exposed by removing the vertical incident component of light passed through a condenser lens. Zero-order diffracted light interferes destructively and the oblique component of .-+.first-order diffracted light, interferes constructively. The obliquely incident component light illuminates a mask having a pattern formed thereon. The vertical incident component of the light is removed by a phase difference of light due to a grating mask or a grating pattern formed on the back surface of the conventional mask. The resolution of a lithography process is improved due to the increased contrast, and the depth of focus is also increased. Thus, patterns for 64 Mb DRAMs can be formed using a conventional projection exposure system.

Projection exposure systems

A projection method uses a modified illumination method for a lithography process of semiconductor device, and a projection system and mask use the projection method. An object is exposed by removing the vertical incident component of light passed through a condenser lens. Zero-order diffracted light interferes destructively and the oblique component of -/+ first-order diffracted light, interferes constructively. The obliquely incident component light illuminates a mask having a pattern formed thereon. The vertical incident component of the light is removed by a phase difference of light due to a grating mask or a grating pattern formed on the back surface of the conventional mask. The resolution of a lithography process is improved due to the increased contrast, and the depth of focus is also increased. Thus, patterns for 64 Mb DRAMs can be formed using a conventional projection exposure system.

Projection method and projection system and mask therefor

A projection method uses a modified illumination method for a lithography process of semiconductor device, and a projection system and mask use the projection method. An object is exposed by removing the vertical incident component of light passed through a condenser lens. Zero-order diffracted light interferes destructively and the oblique component of .-+. first-order diffracted light, interferes constructively. The obliquely incident component light illuminates a mask having a pattern formed thereon. The vertical incident component of the light is removed by a phase difference of light due to a grating mask or a grating pattern formed on the back surface of the conventional mask. The resolution of a lithography process is improved due to the increased contrast, and the depth of focus is also increased. Thus, patterns for 64 Mb DRAMs can be formed using a conventional projection exposure system.

Growing community of inventors

Suwon, South Korea

Seong-oon Choi