Patent ID: 7372091

Claim:
A vertical memory cell, comprising: a substantially planar surface; a first insulator adjacent the planar surface, a second insulator spaced apart from the first insulator, wherein an annular depression is formed in the first insulator and the second insulator; an access device including a mesa, the mesa formed partly within the annular depression and extending outwardly from the planar surface; a buried conductive path bounded by the first insulator and the second insulator, the buried conductive path enclosing a section of the mesa, the mesa circumferentially contacting the buried conductive path at a specified radius along a vertical sidewall region of the mesa above the first insulator, wherein a portion of the mesa extending radially inward from the buried conductive path and extending vertically along the buried conductive path between the first insulator and the second insulator consists essentially of dopant atoms of one conductivity type, and wherein the dopant atoms in the portion form with a diffused concentration profile in the radial direction; and a storage device on the mesa.