Semiconductor memory device

摘要

A drain ( 7 ) includes a lightly-doped shallow impurity region ( 7 a) aligned with a control gate ( 5 ), and a heavily-doped deep impurity region ( 7 b) aligned with a sidewall film ( 8 ) and doped with impurities at a concentration higher than that of the lightly-doped shallow impurity region ( 7 a). The lightly-doped shallow impurity region ( 7 a) leads to improvement of the short-channel effect and programming efficiency. A drain contact hole forming portion ( 70 ) is provided to the heavily-doped impurity region ( 7 b) to reduce the contact resistance at the drain ( 7 ).