Patent ID: 7205598

Claim:
An integrated circuit device comprising: an access device comprising: a substrate having a surface; a pillar of semiconductor material extending from the substrate surface and having a first doped region formed in the semiconductor material at a first end of the pillar and having a second doped region formed in the semiconductor material at a second end of the pillar, the pillar being configured to form the channel of a transistor; a first at least semi-annular ring disposed about at least a portion of the pillar, wherein the first at least semi-annular ring comprises a conductive material; and a second at least semi-annular ring disposed about at least a portion of the pillar, wherein the second at least semi-annular ring is electrically isolated from the first at least semi-annular ring and is more proximate to the substrate surface than the first at least semi-annular ring, and wherein the second at least semi-annular ring comprises a conductive material; and a memory cell in contact with the first doped region, access to the memory cell being controlled by the access device.