| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in 1T-DRAM that a high GIDL current is mainly caused by a leak current at a PN junction, and it may be a cause of generating a leak current at data holding, which reduces a charge holding time in DRAM. <P>SOLUTION: A portion of a drain diffusion layer which overlaps with a gate electrode is divided into two portions being different in impurity concentration. One portion of the two portions is lower in impurity concentration, which adjoins a body part to reduce electric field, thereby suppressing a leak current. At the other portion which is high in impurity concentration, which is insulated from the body part, a relatively large tunnel effect is available at an interface to a gate insulating layer. As a result, while GIDL current is increased, a leak current caused by PN junction is suppressed, to allow extension of the data holding time. <P>COPYRIGHT: (C)2013,JPO&INPIT |
