Access devices formed with conductive contacts
View Patent ↗Systems, apparatuses and methods related to access devices formed with conductive contacts are described. An example apparatus may include an access device that includes a field-effect transistor (FET). A vertical pillar may be formed to include a channel of the FET, with a portion of the vertical pillar formed between at least two gates of the FET (i.e., a multi-gate Fin-FET). A conductive contact may be coupled to a body region of the vertical pillar.
1. An apparatus, comprising:
an access device comprising a field-effect transistor (FET);
a vertical pillar formed to include a channel of the FET, a portion of the vertical pillar formed between at least two gates of the FET (a multi-gate Fin-FET); and
a conductive contact coupled to a body region between the at least two gates positioned on opposite sides of the vertical pillar and within a volume of the vertical pillar determined by areas of the at least two gates.
2. The apparatus of claim 1 , wherein:
the conductive contact is formed from a conductive material; and
the conductive contact is further coupled to a component at a particular bias voltage.
3. The apparatus of claim 1 , wherein the conductive contact is formed from a conductive material that includes at least one of silicon (Si), polycrystalline silicon (polySi), P + Si, P + polySi, germanium (Ge), and Si-Ge (Si 1-x Ge x ).
4. The apparatus of claim 1 , wherein the conductive contact is formed from a conductive material that includes at least one conductive metal.
5. The apparatus of claim 1 , wherein:
the conductive contact is coupled substantially orthogonally to a side surface of the vertical pillar; and
the side surface is substantially parallel to a longitudinal axis of the vertical pillar.
6. The apparatus of claim 1 , wherein:
a storage node is coupled to the access device; and
the storage node and the access device are configured to be operated as a dynamic random access memory (DRAM) cell.
7. The apparatus of claim 1 , wherein the FET of the access device is formed as a metal-oxide semiconductor (MOS).
8. The apparatus of claim 1 , wherein the portion of the vertical pillar is formed between two gates of the multi-gate Fin-FET.
9. The apparatus of claim 1 , wherein the portion of the vertical pillar is formed between three gates of the multi-gate Fin-FET.
10. A system, comprising:
a plurality of dual gate access devices, comprising:
a plurality of trenches formed in a first direction between a corresponding plurality of partitions in an oxide substrate material;
a digit line material to partially fill the plurality of trenches;
an N + polycrystalline silicon (polySi) material formed on the digit line material;
a lightly doped N − material formed on the N + polySi material to fill the plurality of trenches;
a P + polySi material formed as a plurality of conductive contact lines in the first direction on the plurality of partitions; and
a plurality of rails formed from the oxide substrate material in the first direction on a corresponding plurality of the conductive contact lines.
11. The system of claim 10 , wherein the plurality of access devices further comprises:
a plurality of damascene trenches formed in the first direction between a corresponding plurality of the rails; and
a more heavily doped N − polySi material to fill the plurality of damascene trenches.
12. The system of claim 11 , wherein:
the plurality of dual gate access devices further comprises a plurality of trenches formed in a substantially orthogonal second direction;
the plurality of trenches form a plurality of vertical pillars from the more heavily doped N − polySi material in the first direction and the second direction to include channels for a corresponding plurality of the access devices; and
the plurality of vertical pillars are coupled to:
a corresponding plurality of the conductive contact lines; and
the lightly doped N − polySi material in a corresponding plurality of the trenches.
13. The system of claim 12 , wherein the plurality of trenches formed in the second direction extend to an upper surface of the corresponding plurality of the conductive contact lines.
14. The system of claim 12 , wherein the plurality of trenches formed in the second direction extend partially into the corresponding plurality of the conductive contact lines.
15. The system of claim 12 , wherein the plurality of dual gate access devices further comprises:
a gate material formed as separate gates on two opposite surfaces of each of the plurality of vertical pillars in the second direction; and
wherein the gate material is formed:
to couple to the two opposite surfaces of each of the plurality of vertical pillars; and
above the conductive contact lines in order to be uncoupled to the conductive contact lines.