Semiconductor memory devices having selection transistors with nonuniform threshold voltage characteristics

摘要

Provided is a semiconductor memory device. In the semiconductor memory device, a lower selection gate controls a first channel region that is defined at a semiconductor substrate and a second channel region that is defined at the lower portion of an active pattern disposed on the semiconductor substrate. The first threshold voltage of the first channel region is different from the second threshold voltage of the second channel region.

主权项

1. A semiconductor memory device, comprising:
an active pattern on a semiconductor substrate, and extended toward a direction far away from the semiconductor substrate; a nearest gate to the semiconductor substrate, the nearest gate configured to control a semiconductor channel region adjacent the nearest gate, the semiconductor channel region comprising a first channel region that is defined at the semiconductor substrate and a second channel region that is defined at a lower portion of the active pattern; and a selection transistor of non-volatile memory cells on the semiconductor substrate, wherein the selection transistor comprises the nearest gate and the semiconductor channel region therein, and wherein the first channel region extends along a bottom of the nearest gate and the second channel region extends along a sidewall of the nearest gate.