Semiconductor memory device having full depletion type logic transistors and partial depletion type memory transistors

摘要

A semiconductor device includes a semiconductor substrate, an insulating layer, a silicon layer, full depletion type transistors, and partial depletion type transistors. The insulating layer is formed on the Semiconductor substrate. The silicon layer has a first region and a second region. The silicon layer is formed on the insulating layer. The full depletion type transistors are used for a logical circuit, and are formed on the silicon layer at the first region. The partial depletion type transistors are used for a memory cell circuit and are formed on the silicon layer at he second region. The second region of the silicon layer is maintained at a fixed potential.