Memory cells and memory arrays
View Patent ↗Some embodiments include a memory cell having first, second and third transistors, with the second and third transistors being vertically displaced relative to one another. The memory cell has a semiconductor pillar extending along the second and third transistors, with the semiconductor pillar containing channel regions and source/drain regions of the second and third transistors. A capacitor may be electrically coupled between a source/drain region of the first transistor and a gate of the second transistor.
1. A memory cell comprising:
a three-transistor-one-capacitor (3T-1C) configuration; the three transistors of the 3T-1C configuration being a first transistor, a second transistor and a third transistor;
a semiconductor pillar extending along the second and third transistors and comprising channel regions and source/drain regions of the second and third transistors;
wherein all of the first, second and third transistors are vertically displaced relative to one another;
wherein the capacitor of the 3T-1C configuration has an inner node, an outer node, and a dielectric material between the inner and outer nodes; the inner node being electrically coupled with a source/drain region of the first transistor and with a gate of the second transistor;
wherein the first transistor is between the capacitor and a bitline; and
wherein the outer node of the capacitor is against an electrically conductive structure at a common plate voltage, and wherein the semiconductor pillar has an end against said electrically conductive structure.
2. A memory cell comprising:
a three-transistor-one-capacitor (3T-1C) configuration; the three transistors of the 3T-1C configuration being a first transistor, a second transistor and a third transistor;
a write bitline;
the first transistor being under the write bitline and comprising a first channel region between first and second source/drain regions; the first source/drain region being electrically coupled with the write bitline; the first transistor having a first transistor gate along the first channel region;
the capacitor of the 3T-1C configuration being under the first transistor; the capacitor having an inner node, an outer node, and a capacitor dielectric material between the inner and outer nodes; the second source/drain region being electrically coupled with the inner node;
the second transistor having a second transistor gate electrically coupled with the inner node and having a second channel region;
the third transistor being under the second transistor and having a third transistor gate along a third channel region;
a semiconductor pillar extending along the second and third gates; the second and third channel regions being within semiconductor material of the semiconductor pillar;
a read bitline under the third transistor and directly against the semiconductor pillar; and
wherein the second transistor has third and fourth source/drain regions on opposing sides of the second channel region, and the third transistor has fifth and sixth source/drain regions on opposing sides of the third channel region; wherein the fourth and fifth source/drain regions overlap one another within semiconductor material of the semiconductor pillar; wherein the outer node of the capacitor contacts an electrically conductive structure at a common plate voltage; wherein the semiconductor pillar contacts the electrically conductive structure; and wherein the third source/drain region is within the semiconductor pillar and extends to the electrically conductive structure.
3. The memory cell of claim 2 wherein the sixth source/drain region extends to the read bitline.