Methods of manufacturing semiconductor devices

Abstract

Provided are methods of manufacturing semiconductor devices by which two different kinds of contact holes with different sizes are formed using one photolithography process. The methods include preparing a semiconductor substrate in which an active region is titled in a diagonal direction. A hard mask is formed on the entire surface of the semiconductor substrate. A mask hole is patterned not to overlap a word line. A first oxide layer is deposited on the hard mask, and the hard mask is removed to form a piston-shaped sacrificial pattern. A first polysilicon (poly-Si) layer is deposited on the sacrificial pattern and patterned to form a cylindrical first sacrificial mask surrounding the piston-shaped sacrificial pattern. A second oxide layer is coated on the first sacrificial mask to such an extent as to form voids. A second poly-Si layer is deposited in the voids and patterned to form a pillar-shaped second sacrificial mask. The second oxide layer is removed to expose the active region. The sectional area of a buried contact (BC) storage contact pad may be increased, while the sectional area of a direct contact (DC) bit line contact pad may be reduced.