Muncy, Geissler, Olds & Lowe, PLLC
Mask ROM fabrication method
A mask ROM fabrication method which comprises steps: sequentially forming a gate dielectric layer and a first photoresist layer on a substrate; letting a light having a wavelength of 365 nm pass through a first phase shift mask to photolithographically form on the first photoresist layer a plurality of first trenches having a width of 243-365 nm; doping the substrate to form a plurality of embedded bit lines having a width of 243-365 nm; removing the first photoresist layer; sequentially forming a polysilicon layer and a second photoresist layer on the gate dielectric layer; and letting the light pass through a second phase shift mask to photolithographically form a plurality of polysilicon word lines on the polysilicon layer. Thereby is reduced the line width of mask ROM to 243-365 nm and decreased the area of mask ROM.
Nuvoton Technology Corporation Nyquest Technology Corporation Limited
H H H
H01L H01L H01L
inventional additional additional
Cheng Tao Chin-Yung Kuang-Chu Chung-Lung Chun-Yao
Chen Chang Chen Hsu Chiu