SEMICONDUCTOR DEVICE AND SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A semiconductor device and a semiconductor memory are provided to extend data holding time by using a field effect transistor having a low off current as a first field effect transistor. CONSTITUTION: A memory circuit comprises first, second, and third field effect transistors(121,122,123). The first field effect transistor includes an oxide semiconductor layer. Either a source or drain in the first field effect transistor receive data signal. The oxide semiconductor layer includes a pair of regions which respectively include low-dopant region and a high-dopant region contacting a channel. The channel is formed between a pair of the regions. A dopant is added to a pair of the regions.