Image Number 18 for United States Patent #8003457.
A substrate is provided. A pillar protruding out of a surface of the substrate is already formed on the substrate, and a patterned layer is already formed on the pillar. The pillar includes a lower part, a channel region, and an upper part from bottom to top, and the lower part has a first doped region. A gate dielectric layer is formed on a sidewall at one side of the pillar. A surrounding gate is formed on the gate dielectric layer located on the channel region, and a base line electrically connected to the channel region is formed on a sidewall at the other side of the pillar. A second doped region is formed in the upper part of the pillar.