Semiconductor device

A semiconductor device, comprising:

• a substrate;
• an isolation layer defining an active region in the substrate;
• a word line crossing the active region in a first horizontal direction, the word line dividing the active region into a first impurity region and a second impurity region;
• a bit line extending on the substrate in a second horizontal direction orthogonal to the first horizontal direction;
• and
• a direct contact electrically connecting the bit line to the first impurity region, the direct contact having a long axis extending in a third horizontal direction intersecting with the first horizontal direction and the second horizontal direction, and a shape of the direct contact includes a first curve and a second curve that meet on the long axis.

A semiconductor device, comprising:

• a substrate;
• an isolation layer in the substrate;
• active regions defined by the isolation layer, each of the active regions including a first impurity region and second impurity regions, the second impurity regions being separated from each other by the first impurity region;
• word lines extending in a first horizontal direction inside the substrate, each of the word lines crossing between the first impurity region and one of the second impurity regions;
• bit lines extending in a second horizontal direction orthogonal to the first horizontal direction, the bit lines being at a higher vertical level than the word lines;
• and
• direct contacts electrically connecting the bit lines to the first impurity regions, each of the direct contacts having a maximum width in a third horizontal direction intersecting with each of the first horizontal direction and the second horizontal direction at an acute angle,
• wherein the first impurity region has a maximum width in the third horizontal direction.