A dynamic random access memory structure having a vertical floating body
cell includes a semiconductor substrate having a plurality of cylindrical
pillars, an upper conductive region positioned on a top portion of the
cylindrical pillar, a body positioned below the upper conductive portion
in the cylindrical pillar, a bottom conductive portion positioned below
the body in the cylindrical pillar, a gate oxide layer surrounding the
sidewall of the cylindrical pillar and a gate structure surrounding the
gate oxide layer. The upper conductive region serves as a drain
electrode, the bottom conductive region serves as a source electrode and
the body can store carriers such as holes. Preferably, the dynamic random
access memory structure further comprises a conductive layer positioned
on the surface of the semiconductor substrate to electrically connect the
bottom conductive regions in the cylindrical pillars.