Semiconductor device and method of fabricating the same
A semiconductor device includes a semiconductor substrate having a source region and a drain region, a gate formed on the semiconductor substrate, a diode having a cathode region connected to the drain region, and a bit line connected to an anode region of the diode. The drain region and the cathode region are formed by a drain/cathode common region of an N-type semiconductor region.
1 . A semiconductor device comprising:
a semiconductor substrate having a source region and a drain region;
a gate formed on the semiconductor substrate;
a diode having a cathode region connected to the drain region; and
a bit line connected to an anode region of the diode,
the drain region and the cathode region being formed by a drain/cathode common region of an N-type semiconductor region.
2 . The semiconductor device as claimed in claim 1 , wherein the anode region is a P-type semiconductor region having a bottom and sides surrounded by the drain/cathode common region.
3 . The semiconductor device as claimed in claim 2 , further comprising a first silicided metal layer that contacts a surface of the gate, and a second silicided metal layer having a bottom and sides surrounded by the anode region, the second silicided metal layer being connected to the bit line.
4 . The semiconductor device as claimed in claim 1 , wherein the gate comprises a control gate and a floating gate.
5 . The semiconductor device as claimed in claim 4 , wherein data is erased by applying a positive voltage to the semiconductor substrate and applying a negative voltage to the control gate, while the bit line is in an open state.
6 . A method of fabricating a semiconductor device comprising:
forming, by ion implantation, a drain/cathode common region made of an N-type semiconductor in a semiconductor substrate via a first opening formed in a laminate provided on the semiconductor substrate;
forming, by ion implantation, an anode region of a diode made of a P-type semiconductor in the drain/cathode common region through a second opening formed in the laminate, the anode region having a bottom and sides surrounded by the drain/cathode common region; and
connecting the anode region to a bit line.
7 . The method as claimed in claim 6 , further comprising forming a first sidewall on a side of the first opening after ion implantation for forming the drain/cathode common region so that the second opening is defined.
8 . The method as claimed in claim 7 , wherein the first opening is located between gates of adjacent transistors.
9 . The method as claimed in claim 8 , further comprising:
forming a third opening on a side of the second opening after ion implantation for forming the anode region, so that a third opening is defined, and
forming a first silicided metal layer by siliciding surfaces of the gates and simultaneously forming a second silicided metal layer by siliciding a surface of the anode region.