Semiconductor device and method of fabricating the same

A semiconductor device comprising:

• a semiconductor substrate including a plurality of device formation regions defined by a plurality of device isolation grooves, each device formation region comprising a plurality of unit regions, each unit region comprising first and second active regions alternately arranged in series to each other, the first active region extending in the first direction, and the second active region extending obliquely to the first direction;
• a plurality of first semiconductor pillars arranged in the first direction and in each of the first active regions;
• a plurality of second semiconductor pillars, each of which is arranged in each of the second active regions;
• a plurality of first bit lines comprising first diffusion layers in the device formation regions, the first diffusion layers extending under the plurality of first semiconductor pillars and the second semiconductor pillars, each of the first bit lines connecting the plurality of first semiconductor pillars and the second semiconductor pillars in each of the device formation regions;
• a plurality of second diffusion regions on tops of the plurality of first semiconductor pillars and the second semiconductor pillars;
• a plurality of second bit lines electrically connected to the second semiconductor pillars, each of the second bit lines being electrically connected through the plurality of second diffusion regions to the second semiconductor pillars;
• a plurality of second bit lines electrically connected to the second semiconductor pillars;
• a plurality of first insulating layers disposed over the plurality of first semiconductor pillars, the plurality of first insulating layers insulating the second bit lines from the plurality of first semiconductor pillars;
• a plurality of second insulating films on side surfaces of the plurality of first semiconductor pillars and a side surface of the second semiconductor pillar;
• and
• a plurality of word lines on the plurality of second insulating films.

A semiconductor device comprising:

• a device formation region comprising plural pairs of first and second active regions alternately arranged in series to each other;
• a plurality of first semiconductor pillars arranged in the first direction and in each of the first active regions;
• a second semiconductor pillar in each of the second active regions;
• a first bit line comprising a first diffusion layer in the device formation region, the first diffusion layer extending under the plurality of first semiconductor pillars and the second semiconductor pillar, the first bit line connecting the plurality of first semiconductor pillars and the second semiconductor pillar;
• a second bit line electrically connected to the second semiconductor pillar;
• and
• a plurality of first insulating layers disposed over the plurality of first semiconductor pillars, the plurality of first insulating layers insulating the second bit line from the plurality of first semiconductor pillars.