Patent ID: 7652323

Claim:
A semiconductor device having step gates, the device comprising: a semiconductor substrate including first regions having relatively low steps at both ends of an active region defined by trench isolation films, a second region having a relatively high step at a central part of the active region, and a groove having a predetermined depth being formed at a central part of the second region; step gate stacks formed on the first regions and the second region, a portion of the step gate stack being located on the first region and another portion of the step gate stack being located on a top surface of the second region while exposing the groove of the second region; first impurity regions formed in the first regions exposed by the step gate stacks; and a second impurity region formed in the second region exposed by the step gate stacks while enclosing the groove of the second region, wherein the second impurity region is connected with a bit line by the groove while being insulated from the step gate stacks.