CPC H01L 21/76897 (2013.01) [H01L 21/76831 (2013.01); H10B 12/0335 (2023.02); H10B 12/482 (2023.02)] | 8 Claims |
1. A method of fabricating a semiconductor device comprising:
forming a device isolation layer defining a plurality of active regions in a substrate;
forming a conductive layer over the device isolation layer and the active regions;
etching the conductive layer, and forming conductive lines extending in a first direction and trenches between the conductive lines;
forming a spacer on sidewalls of the trenches;
forming hole-shaped recess portions by etching active regions disposed below the trenches so that the active regions are aligned with the spacer,
forming lower-level plugs filling the hole-shaped recess portions;
forming buried bit lines over the lower-level plugs; and
forming upper-level plugs between the buried bit lines by etching the conductive lines along a second direction, the second direction intersecting the first direction.
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